Steering responses of adult and nymphal crickets to light,with special reference to the head rolling movement

Most tethered adult crickets (Gryllus bimaculatus) assumed flight postures with or without flapping their wings in a windstream. Nymphal crickets (sixth and seventh, i.e. final, instars) also displayed the flight posture in spite of the incompleteness of wing development. These adult nymphal crickets rolled their heads towards the light source in response to unequal illumination of the compound eyes only while maintaining the flight posture. The amphtude of the head rolling movements was proportional to the change of light position up to 120°C, and independent of the light intensity if the duration was longer than 1 sec. The unequal illumination could also induce a transient increase in discharge frequency of the wing muscles on both sides, a decrease in wing beat amplitude of the ipsilateral wing on the illuminated side, and bending movements of the legs and abdomen towards the light. Cutting either of the nerve connectives at any level between the subosophageal and metathoracic ganglia did not affect the response of either the head or the abdomen to illumination. These results are discussed in relation to the steering mechanism associated with the dorsal light reaction.     

The posteromedial hypothalamus and pain, behavior, with special reference to endocrinological findings.

Stereotactic intervention into the posterior hypothalamus gives satisfactory results for controlling both aggressive, violent behavioral disorders and intractable pain. From the endocrinological point of view, this procedure activates the hypothalamic-hypophyseal axis only temporarily, without causing any serious dysfunctions.     

Pollen carryover,nectar rewards,and pollinator behavior with special reference to Diervilla lonicera

Summary Pollen carryover was measured in three species of bumble bee pollinated plants by counting the numbers of foreign grains applied to the stigmas of a series of flowers by bumble bees. Deposition declined with the number of flowers visited in a roughly exponential fashion; most grains were deposited on the first few flowers, but some grains went much farther, the maximum carryover being 54 flowers. Variation in deposition was very high. In Diervilla lonicera, bees desposited significantly more grains on flowers which contained large amounts of nectar than on drained flowers. The implications are discussed in terms of plant strategies for optimizing pollination.     

On intrauterine selection by AB0-incompatibility with special reference to maternal age

Summary As follows from the analysis of AB0 system blood-groups for 3186 mothers with children, a selection takes place in the period of intrauterine growth, this selection being directed against AB0-incompatible zygotes (fetuses). Only in the age-group of mothers below 26 a statistically significant (P>99%) selection effect is observed.

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Zusammenfassung Die Analyse der AB0-Blutgruppenverteilung bei 3186 Müttern und ihren Kindern zeigt, daß während der intrauterinen Entwicklung eine gegen AB0-inkompatible Zygoten (Früchte) gerichtete Selektion stattfindet. Der statistisch gesicherte Effekt (P>99%) der Selektion wurde nur bei den jüngeren als 26jährigen Müttern nachgewiesen.

     

Cholinergic innervation to the upper esophageal sphincter muscle in the eel,with special reference to drinking behavior

To elucidate innervation in the upper esophageal sphincter (UES) muscle of the eel, a key muscle in swallowing, repetitive electrical field stimulation (EFS; 30 mA, 40 V, 300 micros, 10 Hz, 10 trains) was employed. Anatomically, the eel UES muscle consists of striated fibers. The EFS-induced contraction of the UES was completely blocked by tetrodotoxin and curare, and abolished in Ca2+ -free Ringer solution. These results suggest that the EFS stimulates nerve fibers specifically and releases acetylcholine as a neurotransmitter. In fact, acetylcholine and carbachol constricted the UES in a concentration-dependent manner. Even after blocking neuronal firing with tetrodotoxin, acetylcholine constricted the UES muscle, suggesting the existence of acetylcholine receptors on the UES muscle cells. Both EFS- and carbachol-evoked contractions of the UES were blocked by curare at a lower concentration than by atropine or hexamethonium, suggesting that the acetylcholine receptor is nicotinic. Even in Ca2+ -free Ringer solution, a direct current stimulus (2 s duration) constricted the UES muscle to an extent similar to that in the presence of Ca2+, indicating that the muscle contraction itself does not need extracellular Ca2+, i.e., the muscle can be constricted by a release of Ca2+ from the sarcoplasmic reticulum.     

Motor unit recruitment in the trapezius muscle with special reference to coarse arm movements.

Chronic shoulder pain is common in a variety of occupations. The "Cinderella hypothesis" suggests that the pain originates from damaged type I muscle fibres driven into degenerative processes as a result of too long activation and too short recovery time. The main purpose of this study was to investigate if the same motor units are active during all phases of coarse arm movements. Eight healthy volunteers participated in the study. Intramuscular electromyographic signals were picked up with a four-lead fine wire electrode, during a unilateral straight arm movement. The movement started with either (part 1) an abduction or a flexion, then (2) a movement in the horizontal plane from the sagittal to the frontal plane or vice versa, and finally (3) an adduction or an extension to the start position. The movement cycle was performed in three different speeds, slow, medium, and high, with one, two or five cycles per 20 s, respectively. On an average, the motor unit action potentials (MUAPs) of 6 motor units (range, 1-15) were identified per trail. In total 94% of the MUAP trains that were identified showed firings in all 3 parts of the movements. The findings support the Cinderella hypothesis, although there is a need to further investigate the temporal pattern of long-term motor unit activity.     

Citrus in West Africa,with special reference to Liberia

Although ample evidence has been gathered to show that citrus can be grown in many parts of West Africa, relatively little of it is cultivated there at present because of difficulties in transportation and communication. Shifting agriculture is still characteristic of the region, and tradition makes the growing of any introduced tree crop difficult.     

Selective mechanisms operating on ABO and MN blood groups with special reference to prezygotic selection

Abstract

There is evidence from diverse sources to indicate that ABO blood groups are subject to natural selection at various developmental stages. This paper reviews the findings on associations between ABO blood groups and diseases and on ABO incompatibility as a major cause of prenatal and perinatal selection; provides evidence for prezygotic selection in ABO blood groups; and discusses selection for heterozygotes in ABO blood groups and in MN blood groups. From the evidence examined, the author concludes that the principal mechanism which maintains the ABO blood groups acts during prenatal and perinatal periods in addition to prezygotic stages; that the effective result of associations between ABO blood groups and adult diseases seems to be small; and that the MN polymorphism is probably maintained by the advantage of heterozygotes, apparently limited to MN mothers.     

ABO blood groups and fertility—with special reference to intrauterine selection due to materno-fetal incompatibility

The purpose of the present investigation was to study whether there is differential fertility between different mating types of ABO blood group system. Selective force which is operating through maternal-fetal incompatibility has been observed in the differential fertility between compatible and incompatible mating groups in the present sample of 183 families of Visakhapatnam town of Andhra Pradesh, India. The differences in the mean numbers of pregnancies as well as living children between the two major mating groups, compatible and incompatible are significant. The fertility rates of O fathers and O mothers were significantly higher than those in matings in which neither parents belongs to O. The selection is operating to reduce the gene ratio of A and to increase the gene ratios of O and B in this sample.     

Paleopathology in an Iroquoian ossuary, with special reference to tuberculosis

Pathological skeletal remains from the Uxbridge Ossuary (1490 +/- 80 A.D., N = 457) are classified into four broad categories: trauma, congenital disability, tumor, and infection. Traumatic injuries are relatively common (fractures in 5-9.4% of total), considering the date and subsistence pattern of the population. Congenital disabilities and tumors are rare, affecting approximately 2% of the population. Nonspecific periosteitis and osteitis affect 5% of the sample. By far the most common pathological skeletal changes are lytic lesions leading to cavitation of cancellous bone, especially in the lower vertebral and sacro-iliac regions. It is argued that the changes seen and their distribution are most consistent with a diagnosis of tuberculosis. Applying clinical observations regarding bone involvement, it is estimated that a minimum of 26 skeletons were affected. This in turn indicates a very high population tuberculosis incidence. The Uxbridge sample is neither the only nor the earliest Iroquoian ossuary to display apparent tuberculosis (Hartney 1981). The common presence of this disease in some communities and its low incidence in others are discussed in the context of the epidemic wave phenomenon. There is strong evidence for warfare at Uxbridge, and this warfare may have produced crowding, poor hygiene and diet, such that the disease could flourish.