Common Cavity Research Articles

Heterostructure injection lasers

A state-of-the-art discussion of heterostructure injection lasers is presented. These lasers are first considered as configurations of uniformly pumped semiconductor slabs that constitute the transmission medium of multilayered slab waveguides, whose boundaries are trapless heterojunctions. Emphasis is on lasers whose electrically active and waveguiding layers are Al x Ga 1-x As or GaAs, although several other semiconductors are discussed. Single, double, and separate confinement hetrostructure lasers, all of which yield carrier and optical confinement normal to the plane of the heterojunctions, are described. Lateral electrical and optical confinement in various stripe geometry double-hetrostructure lasers is illustrated. In addition to the more common Fabry-Perot cavity lasers, there are now also several new varieties that use corrugated surfaces as Bragg gratings for internal distributed feedback or reflection. Some of these heterostructure lasers have permitted the demonstration of CW-room temperature injection lasers with low threshold current densities ( 105) h), and a considerable degree of control over modes and beam divergence. In addition, the use of heterostructures has permitted the demonstration of the first integratedoptical structures that include both active light generating and passive elements on a single chip.

Stomach and Upper Intestine of the Rat in the Regulation of Food Intake

The role of the upper intestine in the regulation of food intake and gastric emptying has been studied in normal, gastrectomized, and "crossover" rats, parabiotic rats with a common visceral cavity in which the proximal duodenum of each parabiont is anastomosed to the pylorus of the stomach of the partner. One rat of "crossover" pairs eats and the partner eats little or nothing. Normal rats fed a raw soybean (RS) diet ate less and gastric evacuation proceeded more slowly than in normal rats fed a heated soybean (HS) diet. It is postulated that RS contains a heat-labile intestinal irritant. The upper intestine of gastrectomized rats regulates food intake and prevents overloading of the intestine. Force feeding of excessive amounts of the RS diet elicited the secretion of much more solids and nitrogen into the upper intestine than did similar amounts of the HS diet. The upper intestines of "crossover" rats lose all control over entry of gastric contents into their duodena. Fed ad libitum, the parabiont whose stomach emptied first, ate continuously, while the recipient partner showed diarrhea. It is postulated that the control of food intake traditionally assigned to the stomach resides, rather, in the upper intestine.

Ultrastructure des glandes genales ventrales de Campodea Sensillifera Conde et Mathieu et de C. Kervillei Denis (Diplura)

The ventral genal glands of Campodea sensillifera and C. kervillei are integumentary glands that secrete into the gnathal cavity. They are composed of cells which open into a common cavity by means of ductules. The glandular cells have a reservoir without receptor tubules. The cytoplasm is packed with rough endoplasmic reticulum from which secretion granules arise. Secretion is discharged without changes in the ultrastructure of the granules, and is probably proteinaceous in nature. The glands are innervated with axon endings that are without glial sheath and filled with aminergic granules.

Effect of increased intraabdominal pressure on lower esophageal sphincter pressure.

This study evaluates the effect of intraabdominal pressure increases on lower esophageal sphincter (LES) pressure in normal subjects and in patients with reflux esophagitis. Intraabdominal and intragastric pressure were increased by abdominal compression, the Valsalva maneuver, and leg raising. In normal subjects changes in pressure recorded from the LES equaled the changes in gastric pressure induced by abdominal compression and Valsalva. Consquently the LES-gastric pressure gradient remained unchanged. During leg raising, pressure recorded from the LES increased more than gastric pressure, thereby increasing the LES-gastric pressure gradient. Although statistically significant, the LES pressure increases associated with leg raising were modest, unrelated to initial sphincter pressure, and unaffected by atropine. When individuals demonstrating a "common cavity" phenomenon were exculed, LES pressure changes during abdominal compression were similar in patients with esophagitis and in normal volunteers. Consequently, response of the LES to abdominal compression generally does not separate patients with esophagitis from normal subjects. We believe that the LES responses to increased intra-abdominal pressure observed in this study are better accounted for by mechanical factors than by a physiologic adaptive response of intrinsic LES tone.

A Commercial Microwave Oven Using a Near Field Applicator*

ABSTRACTA new commercial microwave oven using a near field applicator instead of the common multi-mode resonant cavity principle is described. It offers advantages such as reduced edge heating effect, high microwave efficiency for small food loads and simplified microwave leakage control. The oven is adapted for reheating of pre-cooked food on a plate or in a paper-plastic container. The one-sided microwave penetration is considered a negligible drawback, as most load types for which the oven is used are thin and the use of plastic-paper containers eliminates the problems associated with metal foil containers.

Radiaxial fibrous calcite: a replacement after acicular carbonate

ABSTRACTRadiaxial fibrous calcite, a common cavity fill in ancient limestones, is characterized by curved twin lamellae, optic axes that converge away from the substrate and subcrystals which diverge in this same direction. The optic axes radiate about three or four axes located in positions between adjacent crystals and orientated parallel with the crystal elongation. The crystals are commonly turbid with inclusions, which may be concentrated along twin lamellae and subcrystal and inter‐crystalline boundaries, or form zones parallel to the substrate. Some inclusion patterns reveal the position of former crystal faces.From a consideration of the occurrences, gross morphological characters, the fabrics of the crystals and the inclusion patterns, radiaxial fibrous calcite is interpreted as a replacement of an early diagenetic acicular cement, composed of interfering bundles of radiating crystals. It is suggested that replacement takes place by a solution‐precipitation process and the migration of a fluid film through the acicular host, with replacement occurring most rapidly between bundles of acicular carbonate. The optic axis pattern of the fibrous calcite is considered to be inherited from the c‐axis orientations of the host acicular crystals. Fibrous calcite intercrystalline boundaries form as fractures after replacement. Some inclusion patterns record the characters of the replaced acicular cement; others, formed of impurities reorganized during the replacement, reveal the form of the replacement front.

Ultrastructure of the protonephridial system of Polystomoides malayi Rohde and P. renschi Rohde (Monogenea: Polystomatidae)

Rohde K. 1973. Ultrastructure of the protonephridial system of Polystomoides malayi Rohde and P. renschi Rohde (Monogenea : Polystomatidae). International Journal for Parasitology 3: 329–333. Polystomoides malayi and P. renschi have three types of protonephridial flames. The first type is a typical flame cell with internal and external ribs connected by a weir membrane without nephrostomes, and with internal and external leptotriches. The second type is a flame cell complex consisting of at least two flames reaching into a common cavity. The third type is a non-terminal (= lateral) flame in the protonephridial ducts, consisting of loosely arranged cilia many of which have lateral tube-like extensions and whose tips have irregularly arranged filaments gradually decreasing in number. The number of cilia in all types of flames varies. The smallest capillaries are strongly convoluted and have a smooth or slightly reticulated surface, the larger ducts have strongly reticulated walls and single cilia may be found in the cavities of the reticulum.

The Mondini type of cochlear malformation. A survey of the literature.

The pathological-anatomical change in the inner ear with congenital perceptive hearing loss is, in some cases, a malformation of the cochlea, where the modiolus is developed in such a manner that only the basal turn of the cochlea is present, while the upper turns form a common cavity—the scala communis. There can also be varying degrees of changes in the pars inferior of the membranous labyrinth and slight changes in the pars superior. This defect (Mondini defect) can be demonstrated by tomography in the axial-pyramidal projection. The Mondini defect is thought to be an arrest malformation occurring in the seventh fetal week, as a nonspecific reaction to a large number of endogenous and exogenous stimuli. It can occur spontaneously, or it can be hereditary, possibly as a part of Pendred's syndrome, where it occurs frequently. Chemical or infectious stimuli can be the cause, and the defect can be found as an isolated phenomenon or as a component of widespread malformation.

Fifteen cases of Pendred's syndrome. Congenital deafness and sporadic goiter.

Pendred's syndrome is defined as a triad: congenital perceptive hearing loss, goiter, and an abnormal perchlorate test. Fifteen patients have been discovered who comply with these three criteria. Bilateral malformation of the cochlea of Mondini type was found in one patient by histological examination. Six, possibly seven, cases of the same defect were found in the remaining 14 patients by tomography of the temporal bones in the axial-pyramidal projection. The most important feature of the defect is that only the basal cochlear turn is retained while the apical turns form a common cavity. The defect is caused by a fault in the development of the modiolus in the seventh fetal week. The lesions in the ears of patients with Pendred's syndrome, similar to the thyroid defect, possibly results from a deficiency in the peroxidase enzyme system.

A test of gastroesophageal sphincter competence. The common cavity test.

Gastroesophageal manometrics, using continuously perfused polyvinyl tubes, and acid reflux (pH test) were studied prospectively in 13 patients with, and 14, without symptoms and/or signs of gastroesophageal reflux. Pressures were recorded simultaneously from stomach, gastroesophageal sphincter and distal esophagus at rest and during gradual abdominal compression to 80 mm Hg. Neither the mean resting pressures nor the mean increase in gastric or sphincter pressures, during abdominal compression, were significantly different (P>0.10). Sphincteric yield pressures did not separate the 2 groups. However, the mean esophageal pressure rise was significantly greater (P<0.001) in the symptomatic patients (34±4.5 vs 9.9±3.2 mm Hg). The mean pressure in the stomach, sphincter and esophagus became almost identical in the symptomatic patients—a “common cavity” occurred between stomach and esophagus. Two symptomatic patients had negative pH but positive common cavity tests. No asymptomatic patient had evidence of either reflux or a positive common cavity test.

Biosystematic Studies onMaianthemum (Liliaceae-Polygonatae)

A similar floral vascular anatomy involving a constant dimerous, bicarpellate plan for each of the threeMaianthemum species is reported. All of the tepal, stamen and ovary traces are derived via repeated radial division of two pedicel bundles. The four tepal and stamen traces are fusion products, as are the two dorsals. A third, smaller (vestigial) pedicel bundle which continues unbranched and uninvolved into the ovary was observed in all three species. It could indicate a past reduction from a trimerous, tricarpellate condition, and gives a basis for comparison to the closely related genusSmilacina. The gynoecial vasculature lacks peripheral laterals, septal axials and terminal cross-connections between the dorsal and ventral supplies. The placentation is only apparently axile, since the two septa divide at the mid-ovary level. Consistently the four co-lateral ovules which are anatropous and bitegmic are supplied by four free placentals. The placentals supplying the two ovules of a given carpel have had a common origin in a single pedicel bundle. Raphides characterize post-fertilization ovaries in all species. ADrusa-type of embyro sac formation shown forM. dilatatum corresponds with that known for the other species. An internal stigmoidal tissue system involving micropylar obturators extends from the base of each locule through the hollow stylar canal. Temporal separation occurs between male and female meiosis (protandry), and outbreeding is further promoted by terminal septal glands functioning as nectaries and the synchronized closure of the common carpellary cavity by inter-digitating papillae on the inner septal margins.

The placenta of the four-eye opossum (Philander opossum).

AbstractThe placental membranes of the four‐eyed opossum were studied by light and electron microscopy. The individual fetuses in each uterus were surrounded by amnion, had allantoic sacs of approximately the same size as each fetus, and were situated in a common yolk sac cavity. The extent of the choriovitelline placenta was marked by a prominent sinus terminalis, and at this margin there was a region where the trophoblast cells penetrated folds of the endometrium. Elsewhere the choriovitelline placenta was closely applied to the uterine epithelium along most of its surface, but the microvilli of the two epithelia did not interdigitate. Numerous inclusion bodies were seen in the trophoblast of both the choriovitelline and bilaminar omphalopleure portions of the placenta, but the aggregates were larger in the latter. The endoderm cells of the choriovitelline placenta had extensive endoplasmic reticulum and numerous mitochondria, but did not have conspicuous absorption canaliculi.Placentation in the four‐eyed opossum appears to represent a progressive advance over that of the Virginia opossum both in confluence of the yolk sacs of the fetuses and in having a region of penetration of the maternal endometrium by trophoblast.

マイズルソウ属の進化生物学的研究

A similar floral vascular anatomy involving a constant dimerous, bicarpellate plan for each of the threeMaianthemum species is reported. All of the tepal, stamen and ovary traces are derived via repeated radial division of two pedicel bundles. The four tepal and stamen traces are fusion products, as are the two dorsals. A third, smaller (vestigial) pedicel bundle which continues unbranched and uninvolved into the ovary was observed in all three species. It could indicate a past reduction from a trimerous, tricarpellate condition, and gives a basis for comparison to the closely related genusSmilacina. The gynoecial vasculature lacks peripheral laterals, septal axials and terminal cross-connections between the dorsal and ventral supplies. The placentation is only apparently axile, since the two septa divide at the mid-ovary level. Consistently the four co-lateral ovules which are anatropous and bitegmic are supplied by four free placentals. The placentals supplying the two ovules of a given carpel have had a common origin in a single pedicel bundle. Raphides characterize post-fertilization ovaries in all species. ADrusa-type of embyro sac formation shown forM. dilatatum corresponds with that known for the other species. An internal stigmoidal tissue system involving micropylar obturators extends from the base of each locule through the hollow stylar canal. Temporal separation occurs between male and female meiosis (protandry), and outbreeding is further promoted by terminal septal glands functioning as nectaries and the synchronized closure of the common carpellary cavity by inter-digitating papillae on the inner septal margins.

The structure and development of the reproductive organs of the female African elephant

The anatomy of the reproductive tract has been studied in several foetuses and one young calf. The external genitalia are characterized by the position of the vulva immediately behind the umbilicus, and a long urogenital canal extending from the vulva to the vaginal opening, which is within the pelvic girdle. The clitoris is relatively large; its tip is partially enveloped in a fold of skin which is referred to as a preputial fold by some writers, but no true prepuce is formed in either sex. The uterine horns of the foetus traverse a ‘ram’s horn’ flexure such as is found in many ungulates, and the mesometrium is produced into elaborate lappets the significance of which is not known. The blood vessels in the region of the kidneys and ovaries were found to be complex and variable in plan. The abdominal reproductive organs are described. The external musculature of the reproductive tract is described. The retractor clitoris (penis) muscle is of unusual form; the muscles of right and left sides do not meet below the rectum and they do not extend far along the genital canal. The ischio-cavernosus muscle is prominent, as is the levator clitoris muscle which appears to have an important function. These muscles are of comparable size and identical disposition in both sexes, at least in foetal stages. The arrangement is contrasted with that in the horse and with that in the hyena, and the significance of the differences is discussed. The bulbo-cavernosus muscle is similar in disposition in both sexes but it is smaller in the female, where the corpus spongiosum is much less prominent. The urethral muscle (compressor of Cowper’s gland) is absent from the female, where Cowper’s gland is relatively minute. A corpus spongiosum is present in the female and is fairly prominent in the foetus, though not comparable in bulk with that of the male. It does not extend to the tip of the clitoris (or of the penis in the male) but does partially invest this organ near its tip by a lateral extension which is served by an elaborate network of nerves and blood vessels homologous with, and similar to, the blood and nerve supply of the true glans penis typical of many mammals. The corpora cavernosa of the clitoris are invested by a thick tunica albuginea, which also invests the strong median tendon into which the levator muscles insert, and extends part way around the roof of the urogenital canal. The two separate uterine cornua unite to form the body of the uterus but the lumina remain separate for most of its length. Implantation usually occurs in this part of the uterus. The two lumina open simply into a common cavity which in turn opens into the vagina, the os uteri being marked by a relatively massive papilla and a prominent sphincter muscle in the foetus. The obstruction evidently becomes progressively less prominent as development proceeds. The vaginal opening into the urogenital canal is complex in early stages and in some foetuses the opening was not patent. The canals of Gaertner were identified in the foetus and were also found in the calf, where they were relatively minute.

Mechanism of Belching: Effects of Gastric Distension With Air

Summary The mechanisms of belching and gastroesophageal reflux have been studied by recording radiologically and manometrically the effects of distending the human stomach with air. After a slight initial rise, intragastric pressure plateaued in the face of continued injection of air, suggesting that both gastric and abdominal cavities relax receptively in response to increased gastric volume. At inconstant time intervals after gastric pressure had reached a plateau, either simple gastroesophageal reflux or reflux with belching occurred in most but not all subjects. During simple reflux, the gastroesophageal barrier opened widely and a common gastroesophageal cavity was established. The esophagus was then emptied of air by a secondary peristaltic wave, returning air to the stomach and reestablishing the competency of the gastroesophageal barrier. No sensations were experiencedduring simple reflux, which appeared to be the result of an involuntary mechanism not involving somatic muscles. Belching, on the other hand, appeared to require contraction of somatic musculature, usually superimposed on antecedent or simultaneous opening of the gastroesophageal barrier, and resulting in the expulsion of air from a common gastroesophageal cavity.

Some experiments on parallel gas lasers within a common optical cavity

Some experiments on parallel gas lasers within a common optical cavity

Iniencephaly.

“Chance favors only the prepared mind.” The purpose of this note is to draw the attention of radiologists to a rare fetal anomaly, iniencephaly, which can be rationally diagnosed in utero radiologically. Incidence: Iniencephaly is said to comprise a little over 1 per cent of all fetal abnormalities (5). The incidence has been estimated to be between 1 in 900 (4) and 1 in 2,200 deliveries (5). Only about 70 cases have been reported. Occurrence of the anomaly, however, is unquestionably greater than indicated by the literature: depending on local interest in teratology, some iniencephalic monsters may be discarded, or assigned to a specimen jar, in either case unreported. Too, there is a reluctance (or inertia) in many quarters to make single case reports. Pathology: The abnormalities of iniencephaly (inion, nape of neck) have been repeatedly detailed throughout the scanty literature, and only the salient findings need be given here: the fetal head is hyperextended, with a much enlarged foramen magnum opening directly into the upper cervical reaches of the spinal canal via defective neural arches and widened pedicles, making essentially a common cavity between the brain and much of the spinal cord. The vertebrae, especially the cervical, are fused, reduced in number, and of bizarre shape. The ventricular system may be dilated, with thinning of the cortex; all degrees of anencephaly may be present (2); the spinal cord is usually defective. There may be a meningocele. The soft parts of the anterior chest pass directly onto the permanently star-gazing face, by-passing a neck, resulting in a characteristic appearance. Associated anomalies of other structures are common, especially talipes and defective diaphragm. Iniencephaly has been regarded as an especially severe form of the Klippel-Feil syndrome (1). Most of these monsters are female, and most are stillborn; survival beyond the first day is rare. Antenatal Diagnosis: As with other fetal anomalies, polyhydramnios is frequent. There is some evidence that the mothers are not young and that there has been a rather long interval since the preceding pregnancy (4). This is doubted by some (5). Breech presentations are common. Delivery may be surprisingly easy, especially in view of the extension of the head, or may be difficult (5). Roentgen examination is the only way by which a positive antenatal diagnosis may be made. Although many of the cases in the literature were so examined, usually for polyhydramnios, never to our knowledge has the specific diagnosis been offered; only that the fetus was abnormal. Nor was the specific diagnosis made in the present case. Case Report Mrs. M. H., white, twenty-eight years old, patient of Drs. Gordon Jones and Lee Earnhardt, had been delivered four years earlier of a normal child who died of “pneumonia” at twenty days. Except for this and early abortions three and two years before, the past history and family history were normal.

Evidence for a humoral factor in vagotomy-induced pulmonary edema

Two types of experiments were performed on unanesthetized guinea pigs: a) acute parabiotic union with common peritoneal cavity; and b) continuous cross circulation. Three combinations of animal pairs were employed in each type of experiment, grouped as follows: group 1, both partners were not vagotomized; group 2, both partners were vagotomized; group 3, one partner was vagotomized and its mate was not vagotomized. Lung-to-body weight ratio served as the index of pulmonary edema. In the parabiosis series, the vagotomized partner of group 3 was protected from edema by being joined with a nonvagotomized animal. In the cross-circulation series, the nonvagotomized partner of group 3 developed pulmonary edema as a result of being cross-perfused with a vagotomized animal. In both series, survival time of vagotomized animals was prolonged by their being juxtaposed to nonvagotomized animals. Interaction between vagotomized and nonvagotomized partners in parabiosis as well as in cross-circulation experiments is best explained by exchange of an edemagenic substance.

Parabiosis in rabbits as preliminary to homotransplantation of tissues.

Summary1. Prolonged parabiosis in rabbits, which have a complex and sensitive immunologic mechanism, has been unsuccessful. 2. Using a common peritoneal cavity method of parabiosis, rapid absorption of an antigen that is lethal to one of the parabiotic animals occurred in one day. 3. Administration of Evans Blue and pneumococcic polysaccharide prolonged duration of parabiotic union in rabbits by their effect on animals' immune reactions. 4. Secondary and tertiary attempts at parabiosis are rejected more rapidly than the initial parabiosis, again confirming the sensitivity theory of homograft rejection.

Il Fattore Costituzionale Del Cancro Studiato Sul Ratto Col Metodo Della Parabiosi

SummaryWe describe a fortuitous observation on two rats united in parabiosis since nearly a year.One of the two, belonging to an oncoreceptive race, fell sick of a round cell sarcoma, of extremely malignant nature, which spread itself through various metastases to all the organism, invading especially the lungs and causing tha animal’s death.The other, of oncorefractory race, did not fall sick, although he was united to the first by abundant vascular and lymphatic communications, and that the common abdominal cavity was full of an hemorrhagic exsudation containing numberless cells coming from the tumorous decomposition. As the question is of a parabiosis of long duration and of a natural tumor of great malignity, the observation, better than the preceding ones on grafted tumors, favours the demonstration of the importance of the individual constitution of a subject sick or not of cancer.