Search

A 74-item attitude questionnaire was administered in six companies to 101 black and 87 white male blue-collar employees holding similar jobs in the same company. Differences between the two ethnic groups were not marked, both in terms of job satisfaction and in other respects; Where there were differences the black workers were usually slightly more favorable. However, the picture was not uniform across the different companies.

In response to internal parasitization by Banchus flavescens Cresson, larvae of Trichoplusia ni (Hubner) form a bubble-like cyst between the cuticle and epidermis on the dorsum of the penultimate segment. After the parasite egg hatches, its larva migrates to and enters the cyst and is then sluffed off with the exuviae at the next moult. The nature and development of the cyst is discussed. We propose that this unique and successful defense reaction by T. ni be called cuticular encystment.

The metamorphosis of 19 Atrichopogon species, 14 of which are described as new, is treated from a morphological point of view. Most of the characters that are employed in distinguishing adults of the species are of a quantitative nature and subject to great individual variation. Hence, we are forced to base the taxonomy to a great extent upon the immature stages; and yet at present the genus can be clearly separated from Forcipomyia only by adult characters. Three broad groups are distinguished on the basis of larval morphology. They are presented with the object of providing a foundation for the establishment of subgenera in the future when more material becomes available.

The gross anatomy of the central nervous system and retrocerebral complex of adult Liocoris unctuosus is described and figured. There are three ventral ganglia; the suboesophageal and first thoracic ganglia are separate, while the second and third thoracic are fused with the abdominal ganglia into a common center. Innervation of the reproductive organs in the male is described. The retrocerebral complex consists of the hypocerebral ganglion, paired corpora paracardiaca, and a single corpus allatum, and their associated nerves.

In the first paper on this subject Arnot and Milligan (1936), using a mass spectrograph, showed that diatomic mercury molecules were formed by attachment of excited atoms to normal atoms, the products of the collision being an ionized molecule and a free electron. It was shown that for this process to occur the excited atom must be in an energy state about 9⋅5 V above the normal. The primary object of the work described in this paper was to determine this appearance potential more precisely by using the balanced space charge method. The lowest excited state of an atom which, on collision with a normal atom, leads to the formation of a molecular ion is shown to be the 6 s 8 p 4 1 P 1 state of 9⋅722 V energy. In addition we have detected molecular ions formed by the attachment of two excited atoms, and evidence is put forward to show that only atoms in P states form attachments with normal atoms which lead to the formation of molecular ions.

A fungus of the genus Entomophthora attacks female fifth instar nymphs and adults of the alfalfa plant bug, Adelphocoris lineolatus (Goeze). It destroys all the non-chitinized tissues of the abdomen, beginning with the ovaries and fat bodies, but does not invade tissues of the thorax and head. However, perhaps in response to the effects of castration by the parasite, activity in the host's neurosecretory A-cells of the brain ceases and the corpus allatum hypertrophies.

Neurosecretory cells of only one type (A, sub type A2) are seen in adult Melanoplus. Two groups of about 400 cells each are located dorsally in the pars intercerebralis medialis; four cells are located deep within the protocerebrum. We found no neurosecretory cells in other parts of the central or sympathetic nervous systems. In about 10% of the specimens, there was marked asymmetry in the location of the dorsal cell groups, with both of these groups and their axons located in one lobe of the protocerebrum. The nervi corporis cardiaci 1 cross-over in the corpus cardiacum, with the result that material produced by neurosecretory cells on one side of the brain is transported along axons that undergo two chiasmata to the corpus cardiacum of the same side. Stainable secretory material could be traced clearly from the cerebral cells to the corpus cardiacum, and even into the oesophageal nerves from the hypocerebral ganglion. However, stainable neurosecretory material is never present in the corpus allatum or along any of the nerves to this gland.

The occurrence of band spectra in the chemically monatomic gases leads to the belief that molecules are formed in the gas by the electrons or photons producing the spectra. Arnot and Milligan (1936) and Arnot and M’Ewen (1938) have shown that diatomic mercury molecules are formed by the attachment of excited atoms in P-states to each other and to normal atoms. Although it has been inferred from the band spectra found in helium that molecules are formed by some such attachment process, these have not previously been studied electrically, nor have the details of the attachment process been investigated. No definite evidence has been put forward to show that band spectra occur in the other rare gases. This paper contains the results of an investigation made by the balanced space-charge method of the ionization produced in argon, neon and helium when these gases are subjected to bombardment by electrons whose energy was varied from a few volts below the first excitation potential to a few volts above the atomic ionization potential of the gas. Only atomic ionization has been found to occur in argon and neon, but molecular ions are found to be produced in helium when the energy of the electrons exceeds the resonance potential of the gas.

During some experiments involving the acceleration and subsequent retardation of positive ions of mercury we found that the retarding potential had to be twice as great as the accelerating potential in order to stop completely the flow of ions. Investigation showed that this was due to some ions being accelerated as doubly charged Hg 2+ ions and retarded as singly charged Hg + ions, the change of charge being due to the Hg 2+ ion capturing an electron from a neutral atom with which it collided in the space between the accelerating and retarding fields. Since this process of electron transfer in mercury vapour had not been previously studied in detail we modified the apparatus to enable it to be investigated.

Summary.— A patient with histologically proven Crohn's disease of the ileum and caecum presented with unusual ulceration of the mouth 3 years after subtotal colectomy. Worsening of bowel symptoms was associated with exacerbation of oral ulceration on several occasions. The areas of ulceration in the mouth were in relation to a sarcoid reaction typical of Crohn's disease.

The rate of egg-laying by female Melanoplus sanguinipes was reduced to about 60 per cent of that for normal mated females following severance of the recurrent nerve or the frontal ganglion connectives or removal of the frontal ganglion, but it was still somewhat higher than the rate for normal virgin females. Although the fat body was markedly reduced in size, the fact that eggs and some faeces were produced suggests that protein digestion and synthesis did not stop in our experimental insects. Feeding was not affected but food passage along the gut was severely restricted following these operations; however, the corpus allatum was not affected.

The morphology of the cephalic ganglia and their main nerves in Adelphocoris lineolatus (Goeze), including the sympathetic system of the head and the retrocerebral complex, is described and figured, and compared with that of Liocoris unctuosus Kelton. There are only two ganglia in the ventral chain; the suboesophageal and prothoracic ganglia make up one unit; the meso- and meta-thoracic and all the abdominal ganglia and, fused into a common mesothoracic center, make up the second. The major nerve branches from these centers are also described. A distinct branch, the "nerf laterale," from the suboesophageal–prothoracic ganglion to the corpora paracardiaca, was seen. This ganglion also innervates the thoracic glands. The sympathetic system of the head includes the frontal ganglion and its connectives, a single recurrent nerve, the hypocerebral ganglion, and an unpaired oesophageal nerve. The corpora paracardiaca are paired and are closely applied to the anterior surface of the unpaired corpus allatum.

Melanotic lesions were found in several tissues of larval Drosophila melanogaster following treatment with Rous sarcoma virus, methylcholanthrene, and dimethyl sulfoxide. Similar lesions were found in adults of Melanoplus sanguinipes after they had been injected with sublethal doses of an insecticide. We do not think that either of these lesions are analogous to mammalian neoplasia, and thus should not be called “tumors.”

The synthetic ability of type-A neurosecretory cells (NSC) and corpus allatum (CA) was investigated autoradiographically in both normal virgin females and those from which the frontal ganglion had been removed. Incorporation of3H-cystine and3H-uridine into the NSC was significantly lower in frontal ganglionectomized insects than in controls. There appeared to be no relationship between the level of isotope uptake and the amount of stainable material in the NSC. Ability of the CA to incorporate3H-uridine seemed unaffected by the operation.

Following removal of the corpora allata from newly emerged adult females of Melanoplus sanguinipes there was no maturation of eggs by about two-thirds of the operated animals. The remaining one-third had well-developed ovaries and deposited normal egg pods, but at a reduced rate as compared with normal females. There was marked growth of nervous and connective tissue from the area of the corpus cardiacum in these egg-laying, allatectomized females. We suggest that this regenerative-type growth of nervous and connective tissue may stimulate the cerebral neurosecretory cells and that the cerebral hormone(s) may be responsible for the maturation and deposition of eggs.

The rate of egg deposition by mature virgin females of the migratory grasshopper, Melanoplus sanguinipes (F.), increased markedly after implantation of accessory glands from mature males. Implants consisting of one-half of a complete set of glands, or of the 10 short hyaline glands alone, were about equally effective in increasing the rate of egg deposition. However, in each case the oviposition rate was less than that of normally mated females of the same age. Implanting only the white glands of the accessory gland complex had a lesser effect on egg-laying and implants of the long hyaline gland or of the seminal vesicle had little or no effect.Our results indicate that the physical act of mating per se or the presence of sperm probably do not provide the primary stimulus to egg-laying. The abdominal location of the implanted accessory gland does, however, suggest that some diffusible chemical substance is responsible for increasing egg deposition in these virgin females.

1. Free perforation is a not infrequent complication of regional enteritis; 95 cases have now been recorded. It can occur in any age group and at any stage in the disease.

The corpus allatum undergoes marked changes in volume and histological appearance during egg maturation in the adult female of Adelphacoris lineolatus (Goeze). The allatum is very active just before yolk is deposited in the developing oöcytes, but activity declines rapidly at oviposition. This activity in the corpus allatum cannot be correlated with cyclical activity in the cerebral neurosecretory cells. Experiments involving removal of the corpus allatum show that the gland is necessary for oöcyte growth. Implantation of active corpora allata into allatectomized females will not restore egg maturation, and the implanted glands lose their secretory ability. It seems that the corpus allatum in this insect must retain anatomical connection with the central nervous system to produce its hormone.

SUMMARY.— A case of generalized muscle weakness due to prolonged chloroquine ingestion is described. The clinical and histological findings are discussed. Eventual recovery of function can be expected.

Immature Drosophila melanogaster were reared on a normal growth medium containing 10 ppm of the carcinogen, aflatoxin B1. Considerable prolongation of the larval and pupal instars resulted, even when the duration of exposure to the carcinogen was only 24 hr. Histological examination of the larvae indicated suppression of activity in the cerebral neurosecretory cells.

Whole Aedes aegypti female mosquitoes were ground and injected into rabbits or guinea pigs. Aedes females that subsequently fed on these sensitized mammals showed substantially reduced fecundity. In another mosquito, Culex tarsalis, that fed on the same mammals, fecundity was not reduced. Other life stages of the mosquitoes apparently were not affected.

This chapter presents the analysis of variance (ANOVA), which is a procedure for testing differences among three or more means for statistical significance. It is also used with just two samples. It permits null hypotheses to be tested that involve the means of three or more samples (groups); however, one-way ANOVA deals with one independent variable. The null hypothesis tested by ANOVA is the means of the populations from which the samples were randomly drawn are all equal; for example, the null hypothesis in the caffeine experiment is H O : μ 1 = μ 2 = μ 3 = μ 4 = μ 5. The alternative hypothesis states that H O is not true. The ANOVA procedure is based on a mathematical proof that the sample data can be made to yield two independent estimates of the population variance. The first step in the ANOVA design is to compute the sum of squares between groups (symbolized by SS B ), the sum of squares within groups (symbolized by SS W ), and the total sum of squares (symbolized by SS T ). A sum of squares is nothing more than a sum of squared deviations.

This chapter describes inferences about the mean of a single population. The chapter states the general considerations for hypothesis testing. The null hypothesis (denoted by the symbol H 0 ) and the alternative hypothesis (denoted by H 1 ) are stated. It is important to understand that it cannot be proved whether H 0 or H 1 is true because the entire population cannot be measured. It is assumed that H 0 is true. Then the data is obtained and the assumption is tested out. If this assumption is unlikely to be true, it is abandoned and the “bets should be switched” to H 1 , otherwise the assumption is retained. Before collecting any data, it is necessary to define in numerical terms what is meant by “unlikely to be true.” In statistical terminology, this is called selecting a criterion (or level) of significance, represented by the symbol a. Having selected a criterion of significance, data is selected and the appropriate statistical test is computed.

To compare scores based on different means and standard deviations, it is desirable to convert the raw scores to transformed scores with a common mean and standard deviation. Some frequently used transformed scores are Z scores (standard scores), with a mean of 0 and a standard deviation of 1 ; T scores, with a mean of 50 and a standard deviation of 10 ; and SAT scores, with a mean of 500 and a standard deviation of 100. A transformed score shows at a glance whether a score is above or below average, and how far in terms of standard deviation units, with respect to a specified reference group. As one function of behavioral scientists is to report test scores to people who are not statistically sophisticated, several alternatives to Z scores have been developed. The mean and standard deviation of each such common denominator have been chosen so that all scores are positive, and so that the mean and standard deviation will be reasonably easy to remember.

Publisher Summary A normal distribution model is a theoretical distribution as its shape is defined by a mathematical equation and it would never be exactly duplicated by empirical data. One frequently used theoretical model is the normal curve. One use of this model is as follows: If it is assumed that raw scores in the population are normally distributed, and that one knows or can estimate the population mean and standard deviation, one can obtain the percent of the population with raw scores above or below or between specified values and/or the raw score that demarcates specified percent in the population. The shape of the normal curve looks like a bell; it is high in the middle and low at either ends or tails. Values in the middle of the curve (close to the mean of the distribution) have a greater probability of occurring than values further away (nearer the tails of the distribution). The normal curve is unimodal, as it has one peak and is symmetrical. The normal curve does not touch the X axis until it reaches (+ and –) infinity. Extreme positive and negative values can occur, but are extremely unlikely.

Publisher Summary This chapter focuses on other correlational techniques. With ranked data, the Spearman rank-order correlation coefficient is used. With one continuous and one dichotomous variable, the point biserial correlation coefficient (rpb) is used. Alternatively, the correlation could be computed by using the formula for the Pearson r. rpb is tested for significance in the same way as the Pearson r.

The primary goal of descriptive statistics is to bring order out of chaos. Descriptive statistics help resolve problems by making it possible to summarize and describe large quantities of data. Among the various techniques that are found particularly useful are the following: (1) frequency distributions and graphs; (2) measures of central tendency; (3) measures of variability; and (4) transformed scores. Each of these procedures serves a different and important function. The first step in constructing a regular frequency distribution is to list every score value in the first column. This chapter explains how to make a complete regular frequency distribution table, a cumulative frequency distribution table, and grouped frequency distributions. It is often effective to express frequency distributions pictorially as well as in tables. The two procedures for accomplishing this are: (1) histograms or bar graphs and; (2) regular frequency polygons and cumulative frequency polygons. Cumulative frequency distributions are also commonly graphed in the form of frequency polygons, and the resulting figure is called a cumulative frequency polygon. The chapter also discusses the shapes of frequency distributions.

Publisher Summary The testing of hypotheses about frequency data falling in category-sets is similar in strategy to testing differences between an observed sample mean and the hypothesized value of the population mean. A question normally asked by an investigator dealing with frequencies is: Can the differences between the observed frequencies (symbolized as fO) and the frequencies expected if the null hypothesis is true (symbolized as fe) be attributed to random sampling fluctuations, or are the differences likely to be because of non-chance factors—that is, to the falsity of the null hypothesis? The statistic used to test such hypotheses is chi square χ2. If the differences between the observed frequencies and the expected frequencies are small, therefore, χ2 will be small. The greater the difference between the observed frequencies and those expected under the null hypothesis, the larger χ2 will be. If the differences between observed and expected values are so large collectively as to occur by chance only .05 or less of the time when the null hypothesis is true, the null hypothesis is rejected.

This chapter discusses the concepts involved in power analysis. It presents the methods for accomplishing the two major kinds of power analysis, which can be applied to the null hypothesis tests. There are four major parameters involved in power analysis, such as the significance criterion, the sample size, the population effect size, and power. These four parameters are mathematically related in such a way that any one of them is an exact function of the other three. The chapter discusses how power analysis of significance tests of the Pearson r of a sample proceeds quite simply. The test of the difference between the means of two independently drawn random samples is probably the most frequently performed test in the behavioral sciences. The chapter also presents the techniques for determining power that make possible the planning of efficient experiments designed to yield more conclusive statements if H O is not rejected.

The histochemical demonstration of catecholamines, tyramines, tryptamines, and related substances depends upon condensation reactions leading to ring closure, ultimately forming a fluorescentisoquinoline, quinonoid or β-carboline. At present, formaldehyde is widely used for such reactions. In this paper the possibilities of other histochemical reagents are considered, and preliminary results obtained with fixative vapours of some other aldehydes (acetaldehyde, glutaraldehyde) and carboxylic acids (formic and acetic acids) are described.

Publisher Summary This chapter describes three main topics: the description of the relationship between two variables for a set of observations; making inferences about the strength of the relationship between two variables in a population given the data of a sample; and the prediction or estimation of values on one variable from observations on another variable with which it is paired. The chapter discusses the principles of linear regression, computation of the equations for predicting y from x and x from y, and how to measure prediction error, the standard error of estimate. Correlation refers to the co-relationship between two variables. The Pearson r coefficient is a useful measure of linear correlation; the sign of r indicates the direction of the relationship and the size of the numerical value of r indicates the strength of the relationship. The maximum values of the Pearson r are: –1 (perfect negative linear relationship) and +1 (perfect positive linear relationship). The Pearson r can be tested for statistical significance; however, it cannot be interpreted as a percent. Linear regression is used to predict scores on one variable given scores on the other. The standard error of estimate is a measure of error in the prediction process.

This chapter provides a definition of percentile and illustrates the computation of percentiles. The percentile rank corresponding to a given score refers to the percent of cases in a given reference group scoring at or below that score. A specified raw score may be converted to the corresponding percentile rank to express its standing relative to the reference group, or the raw score corresponding to a specified percentile may be determined. The percentile divides the scale into 100 equal parts; however, the decile divides the scale into 10 equal parts and the quartile divides the scale into four equal parts. The score corresponding to the 50th percentile has the unique property that exactly half the scores in the group are higher and exactly half the scores in the group are equal or lower. It is called the median and it is one of the measures of central tendency.

The Pearson correlation coefficient r is an appropriate statistic for describing the relationship between two variables when a linear model is appropriate and when data are continuous. For other kinds of data, however, other correlational techniques are necessary. The Spearman rank-order correlation coefficient, a Pearson r , is used when data are in the form of ranks. The point-biserial correlation coefficient, also a Pearson r , is used when one variable is dichotomous (has only two possible values) and one is continuous. This chapter describes the relationship between one dichotomous and one continuous variable. It examines the biserial correlation coefficient and tetrachoric correlation coefficient. When relationship between two variables is to be determined and both of them are genuinely dichotomous, the appropriate correlation coefficient to compute is the phi coefficient. This coefficient is closely related to the chi square statistic.

The amyloid material in a series of seven endocrine polypeptide tumours (Apudomas) has been compared, in a variety of histochemical tests, with that present in two unselected cases of secondary amyloid. Significant differences include the absence, from apudamyloid, of tryptophan and tyrosine. The N-terminal immunoglobulin light chain sequence hypothesis of Glenneret al. (1971), which derives secondary amyloid fibril protein from this source, is strongly supported by histochemical evidence. Absence of the two aromatic amino acids from apudamyloids indicates a different source for their fibril protein. It is suggested that in the case of insulinomas the fibril protein is derived from C-peptide chains and that similar products (prohormone derivatives or amine-binding granule protein derivatives) are responsible for other endocrine tumour amyloids. The hyaline materials deposited in abnormal isletβ cells, and pituitary hyaline basophils (ACTH-secreting Crooke cells), may clearly have a similar type of origin. The autofluorescence of immune amyloid has been shown to be due to oxidation of some of its tryptophan residues toN′-formylkynurenine. The mechanism by which this occurs is unknown but the participation of tryptophan pyrrolase is presumed.