Identification of a new contingency-based response in honey bees (Apis mellifera) through revision of the proboscis extension conditioning paradigm

The two experiments reported present new information in the area of classical conditioning experiments with honey bees. Experiment 1 establishes a single unconditioned stimulus (US) technique as a preferred technique for conditioning of the proboscis extension response. Experiment 1 further identifies a new head turn response which occurs when the standard compound US technique is used. Experiment 2 demonstrates that the newly identified head turn response is contingency-based and provides important new response to the repertoire of honey bee learning experiments.     

A DNA microarray-based methylation-sensitive (MS)-AFLP hybridization method for genetic and epigenetic analyses

We previously developed a PCR-based DNA fingerprinting technique named the Methylation Sensitive (MS)-AFLP method, which permits comparative genome-wide scanning of methylation status with a manageable number of fingerprinting experiments. The technique uses the methylation sensitive restriction enzyme Not I in the context of the existing Amplified Fragment Length Polymorphism (AFLP) method. Here we report the successful conversion of this gel electrophoresis-based DNA fingerprinting technique into a DNA microarray hybridization technique (DNA Microarray MS-AFLP). By performing a total of 30 (15×2 reciprocal labeling) DNA Microarray MS-AFLP hybridization experiments on genomic DNA from two breast and three prostate cancer cell lines in all pairwise combinations, and Southern hybridization experiments using more than 100 different probes, we have demonstrated that the DNA Microarray MS-AFLP is a reliable method for genetic and epigenetic analyses. No statistically significant differences were observed in the number of differences between the breast-prostate hybridization experiments and the breast-breast or prostate-prostate comparisons.Electronic Supplementary Material Supplementary material is available in the online version of this article at Communicated by M. Johnston     

THE PREPARATION OF THE GRADED COLLODION MEMBRANES OF ELFORD AND THEIR USE IN THE STUDY OF FILTERABLE VIRUSES

1. The method described by Elford for the preparation of graded collodion membranes suitable for ultrafiltration was found to give excellent results, and his findings are fully confirmed. 2. A formula is given for the preparation of collodion from which satisfactory membranes of graded porosity can be prepared. 3. The technique and apparatus used in the preparation, and standardization of membranes are described in detail. 4. The technique and apparatus required for ultrafiltration experiments are described, and some drawbacks encountered in the experiments are discussed. 5. The results of ultrafiltration experiments show that the pores of the membranes are remarkably uniform in size.     

Optimizing the application of entomopathogenic nematodes: experimental set-up

The complex issue concerning the spray application of Entomopathogenic Nematodes (EPNs) with a hydraulic sprayer is still not solved. This research project focuses on the effect of spray application technique on the viability and deposition of EPNs. In this paper the experimental set-up used for this evaluation is described. A modular spray application system has been developed and is currently used to evaluate the effect of different parts of a sprayer on the viability of the EPNs. Based on the results of experiments using this modular spray application system, recommendations regarding pump type, mixing system, nozzle type and filter size will be formulated. Because of the large number of experiments in this research project, an image analysis system for the determination of the viability of the nematodes is developed. This paper describes two experiments comparing the new developed image processing technique with the standard microscopic counting technique.     

SOME STUDIES OF THE COLONY COUNT TECHNIQUE FOR SOIL BACTERIA

SUMMARY: A series of co-operative experiments was conducted to compare the bacterial colony counts of soil obtained by workers in different laboratories, using soil extract agar and other media for the determinations.
In the earlier experiments it was not possible to obtain a reasonable degree of reproducibility of results between laboratories even when the plating technique was carefully prescribed. By modification and more rigid standardization of the technique closer agreement was obtained in subsequent experiments. It is suggested that when co-operative investigations are contemplated the participating laboratories should check their technique by the examination of 'control' soils.
No evidence could be obtained to support the suggestion that higher colony counts are obtained by the use of soil extract media containing extract prepared from the same soil as the sample tested. The source appears to be immaterial so long as the soil for extract preparation is not of extreme type and has been well manured and cultivated.     

软锤石片辨识的实验史及争议

在打制石器中,软锤法能够更有效地控制石片形态,是古人类认知与技术水平提升的一个重要标志。传统认为,使用软锤法打下的石片具有打击泡散漫、台面处有唇等特征。随着针对性实验的开展,上述石片特征已经不再被认为仅是软锤剥片所致,而是打制过程中如打击角度、背缘角等诸多因素共同作用的结果,通过石片特征区分软、硬锤存在很大争议。本文旨在梳理学术界对软锤法的认知过程和系统实验历史。根据国际上大量的实验可知,目前的实验以燧石、黑曜石为主要石料,根据石片特征区分软、硬锤尚存在很大争议,石片特征的产生可能受锤的质地、石料、打制者、打击角度等多种因素的影响,因此,不宜仅凭个别石片特征判断遗址中存在软锤剥片。在对具体考古材料的技术分析中,需综合考量整个石器打制过程中涉及到的多种因素,有必要建立一个汇集实验数据与遗址出土石片相关特征的数据库,为打制技术与技法分析提供更为丰富的对比材料。     

Membrane digestion and transport under physiological conditions: a review of available data

A technique to study membrane digestion and transport in the small intestine under physiological conditions has been developed. The technique is based on a continuous perfusion of a chronically isolated loop of the rat small intestine. Membrane hydrolysis and transport of some nutrients in the rat small intestine in chronic, as well as in acute (in situ) experiments was investigated. The absorption of hexoses and amino acids has been found to be 2.5-4 times higher under physiological conditions than in acute in situ experiments. Both the active transport of glucose released from maltose hydrolysis and the hydrolysis of the latter is increased under physiological conditions. A coupling between the final stages of hydrolysis and the initial stages of transport in chronic experiments was shown to be highly efficient; practically all or nearly all glucose released is being transported without entering the luminal phase. The hydrolysis rate of starch during the perfusion of a small intestinal segment in chronic experiments is many times higher than that in acute experiments or under anaesthesia. The enzymatic and transport activities revealed using a widely accepted technique in situ, the more so, in vitro account for only a small fraction of those which are typical of undisturbed processes under conditions close to the physiological. The levels of functioning of the digestive-transport systems of the small intestine considered as natural levels developed in the process of evolution, actually reflect only residual processes and, in most cases, they account for 1/3 to 1/10 of the true level of an actual physiological process.     

A reliable whole cell clamp technique

This article describes a simple whole cell formation technique that the author invented in teaching and experiments. The implementation of the invented technique is a syringe with a hole and slot. With the newly invented technique, novices will shorten their learning curve and veterans will increase their success rate. The invented technique lightens the labor of the experimenter and improves the success rate and quality of whole cell preparations. The article also provides an idea to design an automated whole cell formation implementation. The tools developed in this technique make the patch-clamp experiment easy to teach and learn.     

A method for plasmid purification directly from yeast

A rapid technique for purifying plasmids from yeast Saccharomyces cerevisiae is described that yields high-quality DNA suitable for bacterial transformation, yeast transformation, and direct DNA sequencing. The method requires only small culture volumes and proprietary bacterial plasmid miniprep kits that allow one to simultaneously prepare a large number of samples in a very short period of time while avoiding the use of toxic organic chemicals. Both yeast single-copy CEN/ARS and high-copy 2micro shuttle plasmids can be isolated using this method. This technique is useful for plasmid purification from yeast two-hybrid experiments as well as yeast genetics and molecular biology experiments.     

ASSESSMENT OF VIABILITY OF FROZEN BONE MARROW CELLS USING A CELL-CULTURE METHOD

The survival of mouse bone marrow after freezing and thawing was assessed using two methods: the spleen-colony technique; and a cell-culture method. The results of these experiments indicate that both methods yield similar estimates of marrow cell viability. It is suggested that the cell-culture method be used as an assay of marrow-cell viability in situations where the spleen-colony technique is not applicable.     

Functional Mixed-Effect Models for Electrophysiological Responses

In electro/psychophysiological experiments, linear mixed-effect modeling is an effective statistical technique for data repeatedly observed from the same experimental participants or stimulus items. This review describes the application of mixed-effect modeling to functional responses, in particular those observed in event-related EEG or MEG experiments, using a discrete wavelet transform. The technique is illustrated with a design with several covariates, and procedures for generating posterior samples and computing a Bayesian false discovery rate are described. Neirofiziologiya/Neurophysiology, Vol. 41, No. 1, pp. 79–87, January–February, 2009.     

Effect of rifampicin on development of tolerance to analgesic actions.

Two series of experiments were performed. In the first series the reaction times of mice were determined using the hotplate technique. In the second series of experiments the reactions of rats were determined using the electric footshock technique. In both series of experiments morphine was observed to alter the responses, and chronic morphine administration resulted in tolerance to these actions of morphine. In both series of experiments, tolerance, defined by these same criteria, was inhibited by the concurrent administration of rifampicin.     

Control of Gaseous Environment of Organisms using a Diffusion Column Technique

A technique based on the theory of steady-state diffusion ofgases in a long column provides a simple means of controllingthe gas concentration in biological experiments. The diffusioncolumn consists of a sand-filled tube with side-arms along itslength. Selected gas concentrations are applied at both endsof the column and maintain a predictable concentration gradientalong the column. The gas composition at each side-arm is thusknown and can be adjusted by alteration of the controlling concentrationsat the ends of the column. The response to gas concentrationof small bodies such as seeds and micro-organisms can be testedby placing them in small cuvettes attached to the side-arms.The technique is well suited for experiments needing a closelygraded series of gaseous concentrations. The design and useof an electrode to monitor oxygen concentration is also described.     

Simultaneous-equation estimation in a clinical trial of the effect of smoking on birth weight

Controlled experiments can be used to study the effects on health of behaviors that cannot be perfectly controlled. A simple statistical technique allows causal effects to be distinguished from selection effects. The technique is applied to measure the effect of maternal smoking on birth weight.     

Combined histochemical staining of 1,2-glycol and sulfate groupings of mucopolysaccharides in paraffin sections

Summary A staining procedure has been developed for the simultaneous demonstration of 1.2-glycol and sulfate groupings of mucopolysaccharides in paraffin sections. It is a combined periodic acid-Schiff (PAS) and acriflavine technique, and by this technique the different groupings of mucopolysaccharides in several tissues of the rat and mouse have been stained. The results of a series of histochemical experiments on the dual staining reaction of the mucopolysaccharides have substantiated the reliability of the present technique.     

Implications of experimental technique for analysis and interpretation of data from animal experiments: outliers and increased variability resulting from failure of intraperitoneal injection procedures

Intraperitoneal (i.p.) injections are widely used in laboratory animal experiments. This technique has a failure rate that is typically reported to be of the order of 10-20%. It is not apparent that failures of i.p. injection and their consequences for the experimental results are as widely recognized as the use of the technique. We illustrate the consequences of i.p. injection failure for the analysis and interpretation of several bioassays. We suggest approaches to data analysis that should be considered, and emphasize the need to recognize and allow for the possibility of i.p. injection failure in the analysis and interpretation of laboratory animal experiments involving this technique.     

Fibroblast monolayer cultures in scintillation counting vials: Metabolic and growth experiments using radioisotopes and a microfluorometric DNA assay

Summary We have developed a simple technique for the investigation of cellular metabolism and growth in cultured human fibroblasts which facilitates experiments using up to 3×10⁵ cells in each of 100 or more culture vessels. The method has been used to study cell growth, glucose utilization and oxidation, and protein, RNA and DNA synthesis. The use of radiolabeled substrates in tracer experiments is simplified since transfer of cell material is not required. Methods for measuring both total cellular protein and DNA have been adapted to this culture system. Although we have used this technique for fibroblast cultures, it also can be easily applied to experiments on any other type of cell that can be grown in a monolayer. Supported by PHS grants AM-02456, AM-05020 and AM-15312, and by the Kroc Foundation. Recipient of Research Career Development Award AM-47142 from NIAMDD     

Measurement of cardiac output in waking rats using a Doppler ultrasonic technic

The ultrasound Doppler technique was used for the determination of cardiac output in conscious Wistar rats. The cuff probes were placed on the ascending aorta and calibrated with the radioactive microsphere technique. The results of experiments show that Doppler ultrasound technique determines the cardiac output with high linearity. The possibility of using both methods in one and the same animal was also confirmed.     

A new method for early in utero experiments in rat embryos: endoscopy

The merits of in vitro and in vivo techniques for experiments in rat embryos are discussed in this paper. Time limitation of culture, which is only feasible during 48 hours, up to day 13 post coitum (p.c.) is a major draw-back in the in vitro whole embryo culture. With the in utero operation technique used to date, no controlled experiments can be performed in rat embryos of 15 days p.c. and younger due to the high mortality of the embryos. Therefore a new technique has been developed, in which successful in utero operations can be performed as early as day 12 of gestation. Controlled micro-injection with the help of an endoscope can be given in any desired embryonic organ or structure. This paper describes this technique. Endoscopy in rat embryos of 12 days p.c. onwards has proven to be a new facility for in utero operations.