Showing papers on "Literature survey published in 1984"

DNA repair protects against cutaneous and internal neoplasia: evidence from xeroderma pigmentosum

Abstract: Xeroderma pigmentosum (XP), is a rare, autosomal recessive disease with sun sensitivity and multiple neoplasms in association with reduced DNA repair. As a reflection of the clinical consequences of deficient DNA repair, XP serves as a model for determining the effects of proficient DNA repair. To estimate the risk of developing neoplasms in XP, we abstracted reports of 726 XP patients (from 41 countries) published from 1874 to 1982. Despite limitations of a literature survey, the XP patients under age 20 years had an estimated 2000-fold increase in frequency of basal cell and squamous cell carcinoma of the skin, of cutaneous melanoma, of cancer of the anterior eye, and of cancer of the anterior tongue, in comparison to the general population. These sites are all potentially exposed to u.v. radiation, a strong carcinogen which produces DNA damage that is poorly repaired by XP cells. XP patients under age 20 years also had an estimated 12-fold increase in occurrence of neoplasms in sites not exposed to u.v. radiation. Among the XP patients under age 40 years with internal cancer, there was a disproportionate representation of malignant neoplasms of the brain (especially sarcomas), and oral cavity (excluding tongue) compared to US whites under age 40 years. These internal neoplasms may be related to exposure to chemical environmental carcinogens that cause DNA damage which, like u.v.-induced damage, is poorly repaired by XP cells. These reports provide no evidence of an increase in XP of common lethal neoplasms such as lymphomas, or female genital tract or endocrine system cancers. These findings suggest that DNA repair plays a role in protection against u.v.-induced neoplasia and in protection against some internal neoplasms in the general population.

From organic metals to superconductors: managing conduction electrons in organic solids

Abstract: The conduction of electricity in organic solids, especially the parameters required for metallic electron flow and the phenomena responsible for its permanent interruption or perpetual flow are discussed in detail. Specifically, the permanent interruption, termed metal-to-insulator transition, or perpetual flow, termed metal-to-superconductor, are discussed as exhibited by tetrathiofulvalene (TTF), tetracyanoquinodimethane (TCNQ), tetraselenafulvalene (TTMTSF), and salts of each of these compounds. A rather extensive literature survey is included with 60 references being cited.

Nitrification inhibitors in agriculture and horticulture: A literature review

Abstract: This literature survey is the English version of P. Kerkhoff and J.H.G. Slangen “Nitrificatieremstoffen in Land- en Tuinbouw, Interne Mededeling 54, Vakgroep Bodemkunde en Bemestingsleer, Landbouwhogeschool, Wageningen, 99 p, 1980”, supplemented by reference to the literature of 1980 and a partly of 1981. The literature cited has been taken from sources in East and West Europe and North America.

Continental margins and the extent and number of the continents

Abstract: A new map of the extent of continental crust shows that the continents are more extensive and less dispersed than they are conventionally thought to be. Their total area is 210.4 × 106 km², or 41% of the earth's surface, and there are 14 of them. Continent-ocean contacts are mapped on the basis of a literature survey, and continent-continent contacts are drawn along plate boundaries; thus although Eurasia is still the largest continent, it does not include the separate continents India and Arabia and surrenders northeastern Siberia to North America. Much of the Arctic Ocean is underlain by North American continental crust, and North America is the second-largest continent. Central America and New Zealand are recognized as continents, the latter being nine-tenths submerged, and there are four microcontinents: Rockall, Seychelles, Agulhas, and Jan Mayen. Several oceanic windows, enclaves within the continents, must be recognized if the extent of the continents is to be accurately delineated. The average thickness of continental crust is 36 km; small continents seem to be thinner than large ones, and height and thickness are strongly interdependent. The total volume of continental crust is 7.2 × 109 km³, somewhat less than the 8.0 × 109 km³ estimate of Ronov and Yaroshevskiy (1977). Mean heights are significantly lower than the 875 m commonly quoted from Kossinna (1933), because submerged parts of the continents (30.6% of their total area) are correctly accounted for; the new estimate of mean height is ∼120 m. The relationship between mean height and area for individual continents, however, is still observed. Modal heights are not correlated with area and are ∼ 250 m for most of the large continents. Certain continents have anomalous mean or modal heights, suggesting that the mean height-area relationship arises from greater relative lengths of orogenic belts around and internal tectonism within larger continents; anomalous modal heights suggest anomalous epeirogenic activity. These results may have implications for the hypsometry of ancient continents: in particular, Pangea need not have had a modal height much different from that observed today.

Sand transport by wind on a wet sand surface

Abstract: Using those results which were judged to be reasonable among various experiments, an equation predicting the threshold shear velocity on a wet sand surface was obtained. Then, based on a literature survey, results from fundamental experiments, and information obtained from a series of field observation carried out by the authors, a hypothesis to explain the blown sand phenomena on a wet sand surface was developed. Experiments with a well-sorted sand having a median diameter of 0.3 mm showed that the prediction was valid if the water content of the sand layer was less than 8 %.

Salt tolerance of food crops: Prospectives for improvements

Abstract: A recent assessment of crop tolerance to salinity employing an extensive literature survey covering 30 years has classified crops into four general tolerance categories based on the electrical conductivity of soil saturation extracts at which yields begin to decline. It is evident that the majority of crop plants for which adequate information exists fall within the sensitive end of the salt tolerance spectrum. This includes such staples as rice, com, and potatoes. Plant salt tolerance is a relative concept and the above categories of necessity tend to obscure varietal and ecotypic differences. This article focuses upon biological variability and its possible exploitation for improving plant salt tolerance both by conventional means and by ‘in vitro’ methods.

Minor elements and ore genesis of the Fankou lead-zinc deposit, China

Abstract: The Fankou Pb-Zn deposit occurs in the Middle-Upper Devonian and Lower Carboniferous carbonate and argillaceous carbonate formations. In principle, the deposit can be classified as a carbonate-hosted strate-bound deposit. Representative sphalerite, galena, and pyrite separates from Fankou have been analysed. For the purpose of comparison a literature survey on minor elements of other districts have been carried out. The comparison of determined data with the quoted data shows that the Fankou sphalerites are rich in Ga, Ge and Ag, but poor in Se and Te; the Fankou galenas are rich in Ag, Hg, Sb and As, but poor in Se, Te, Tl and Bi; the Fankou pyrites are rich in As, Cd and In, but poor in Se, Te, Co and Ni. Zn/Cd and Se/S×10−4 ratios for sphalerites, Sb/Ag, Sb/Bi and Se/S×10−4 ratios for galenas and Co/Ni ratios for pyrites from Fankou and other districts have been calculated. Ga-Ge-Ag atomic ratios in sphalerites, Sb-Bi-Ag atomic ratios in galenas and Co-Ni relations in pyrites have been plotted. The average value (311) of Zn/Cd ratios for sphalerites from Fankou is similar to values of sphalerites from Gaobanhe, Heqing, Accesa and Broken Hill. The average Sb/Ag ratio (0.74) and the Sb-Bi-Ag atomic ratios in Fankou galenas are similar to those in the syngenetic galena from the British Island. The Ga-Ge-Ag atomic ratios for Fankou sphalerites are similar to those for the syngenetic sphalerites and Gorno sphalerites. The average Co/Ni ratio (1.1) for micro to fine-grained pyrites from Fankou laminated-bedded pyrite ore is similar to that (0.8) for the sedimentary pyrites from other districts. As to the fine to medium-grained pyrites from Fankou massive pyritic ores, their higher Co/Ni ratios (1.6–1.8) may relate to the fact that more Ni is lost than Co, during the reformation or recrystallization. Sphalerite, galena and pyrite from Fankou all are rather poor in Se and have very low values of Se/S×10−4, so they may bear no genetic relation to volcanism. To sum up, the following conclusions can be reached: (1) The Fankou deposit possesses some syngenetic features. (2) Evidently it differs from skarn type, hydrothermal type, and volcanogenic type deposits. (3) Surely it is a reformed sedimentary Pb-Zn deposit.

Teacher Stress: A Literature Survey with a Few Surprises.

Abstract: A review of 71 articles on teacher stress revealed little empirical support for the common claim that teaching is a stressful occupation. Seventy percent (70%) of the articles tabulated contained no data support; these papers were expressions of personal opinion and usually contained claims of a high incidence of teacher stress. Only 30% of the articles surveyed offered any empirical support for their claims. Most of these articles focused on identifying the sources of teacher stress. On the whole, the papers reviewed suggest that there is little empirical support for the widespread claim that teaching is a highly stressful job.

Clear cell ovarian adenocarcinoma.

Abstract: A retrospective analysis of the clinico-pathologic aspects of 22 cases of clear cell ovarian carcinoma with a literature survey is the subject of this report. The rarity of these neoplasms below the age of 40 is reaffirmed. Tumor-related hypercalcemia was observed in two patients and postoperative thromboembolic complications were encountered in three others. Electron microscopic examination revealed abundant cytoplasmic glycogen content in two cases. Ten patients in this group and 26% in reported series had coexistent endometriosis. Association with endometrial carcinoma was observed in two patients and was reported in 14% of the cases. No patient of ours with Stage III or IV disease survived 5 years or longer and only 8% have reportedly survived in collective series. There was suggestive evidence of radiation tumor response in two patients with Stage IIC disease who had received 5,000 rads pelvic radiotherapy. Objective partial responses were also observed with adriamycin-, cytoxan-, and cis-platinum-containing combinations. A management plan is outlined.

Recognizing and Preventing Relapse in Patients With Schizophrenia

Abstract: Although clinicians know that the acute symptoms of schizophrenia exacerbate and remit during the course of the illness, few studies detail the process leading to psychotic episodes. As an introduction to the problem of recognizing relapse in schizophrenic outpatients, the author discusses interviews that were conducted with one group of family members and two groups of schizophrenic patients, one whose psychotic episodes had just occurred and one whose episodes had occurred more than six months previously. The results confirm the existence of a prodromal period before relapse and the importance of prompt therapeutic interventions during such periods. Finally, the author presents a literature survey of the role of stress, the family, and psychotropic medication in relation to the relapse process, and discusses comprehensive therapeutic strategies that aim to either prevent or mitigate full-blown relapse.

An experimental study of tone excited heated jets

Abstract: The objective of this investigation was to obtain detailed experimental data on the effects of upstream acoustic excitation on the mixing of heated jets with the surrounding air. Based on the information gathered in the literature survey, a technical approach was developed to carry out a systematic set of mean flowfield measurements for a broad range of jet operating and acoustic excitation conditions. Most of the results were obtained at Mach numbers of 0.3 and 0.8 and total temperatures of up to 800 K. Some measurements were made also for the fully expanded supersonic jet of Mj = 1.15. The maximum level of excitation was Le equal to or less than 150 dB and a range of excitation frequencies up to fe = 4 kHz was used. The important results derived from this study can be summarized as follows: (1) the sensitivity of heated jets to upstream acoustic excitation varies strongly with the jet operating conditions, (2) the threshold excitation level increases with increasing jet temperature, and (3) the preferred Strouhal number does not change significantly with a change of the jet operating conditions.

Thermal and Mechanical Properties of Polyurethane Foams and a Survey of Insulating Concretes at Cryogenic Temperatures.

Abstract: : Thermal and mechanical properties of expanded plastics, foams, are reported. The system studied was rigid, closed cell, CCl3 blown, polyether based polyurethane. The primary temperature range study was 100 to 300K; however, several properties were determined to 4 K. the nominal densities of the foams tested were 32, 64, and 96 Kg/m3. Properties reported are thermal conductivity, thermal expansion, strength and moduli in tension and in compression, proportional limit, yield strength, ultimate strength, and shear strength. Physical properties were determined both parallel and perpendicular to the orthogonal axes of the bulk supplies. The gas content of the specimens was determined using a gas chromatograph mass spectrometer and with gas displacement pychomer. Empirical procedures for estimating the temperature dependent thermophysical properties were developed. These procedures are based on the experimental data and utilize the characterization parameters for molar gas concentration, gas pressure, and cell morphology. Regulations affecting vapor dispersion in the aera around liquefied natural gas facilities make it attractive to construct dikes and impounding areas out of materials having low thermal conductivities. several insulating concretes have the general properties required for such applications. Screening tests were done to determine the thermal con- ductivity, modulus of rupture, and the compressive strength of several polyesterbased materials with glass bead or perlite aggregate and of portland cement based materials with vermiculite or polystyrene aggregate. Abibliography resulting from an extensive literature survey of lightweigth concretes is presented

Experimental study of direct in-situ generation of steam in a line focus solar collector. Final report

Abstract: This report summarizes the results of an investigation to experimentally determine the practicality of generating steam directly within the receiver tube of a parabolic trough solar collector. Identified in the literature as in-situ boiling, this system concept features nucleate boiling and two-phase flow within the receiver tube. This effort included a literature survey of past work, design of a proof-of-concept test, system operation under a range of steam delivery temperatures and qualities, and analysis of the results. The proof-of-concept test was performed using an existing 120 foot long row of collector installed in McKittrick, California.

Clofibrate-induced muscular syndrome. Case report with ultrastructural findings and review of the literature.

Abstract: A 70-year-old man with chronic renal failure was treated with clofibrate, 2.0 g daily for 6 days, and subsequently developed clofibrate-induced muscular syndrome (CMS), i.e., myalgia with severe muscle weakness and tenderness. Elevated muscular enzyme activities were found upon examination of his blood. Electron microscopic studies revealed atrophy of some muscle fibers and massive degenerative changes. The atrophic fibers were associated with damaged neuromuscular junctions. A literature survey of 44 cases with CMS is included.

Reproductive anatomy and morphology of Myrtales in relation to systematics.

Abstract: Evidence from reproductive morphology and anatomy (excluding palynology) favors an inclusive Myrtales of 11 core families (see below) over either a much broader Myrtales, as advocated, for example, by the Englerian school (most recently Melchior, 1964) or a narrower Myrtales and accompanying Lythrales, as advocated by Novak (1961, 1972) and more recently and in a rather different manner by Briggs and Johnson (1979), who, however, withdrew their concept in this symposium (Johnson & Briggs, 1984; see also argumentation in the appendix in Schmid, 1980). Embryology provides the best evidence for a concept of core Myrtales consisting of Combretaceae, Crypteroniaceae, Lythraceae, Melastomataceae sensu lato, Myrtaceae (including Psiloxylaceae3 and Heteropyxidaceae; Schmid, 1980), Oliniaceae, Onagraceae, Penaeaceae, Punicaceae, Sonneratiaceae, and Trapaceae (familial arrangement strictly alphabetical; see also Tobe & Raven, 1983a). The following embryological traits unite core Myrtales: anthers tetrasporangiate*, with conspicuous endothecium*, glandular tapetum, simultaneous cytokinesis; ovules anatropous*, bitegmic*, crassinucellate; antipodals ephemeral or absent*; endosperm nuclear*; seeds exalbuminous*. The asterisks indicate that exceptions are known. Table 1 (pp. 834-835) lists such exceptions, which in some cases are known for only one family or even only one species, for example, the trisporangiate anther of Corynanthera flava of Myrtaceae (Green, 1979). Other embryological features such as nuclear condition of pollen at time of shedding, persistence of anther epidermis, and types of anther wall development, embryo sac, and embryogeny vary appreciably (see Table 1). Significantly, Dahlgren and Thorne (1984) and Tobe and Raven (1983a) independently arrived at a very similar complex of embryological characters unifying core Myrtales. Reproductive anatomy, that is, histology and vasculature, gives no special aid in resolving the makeup of Myrtales. Features such as bicollateral bundles (internal or intraxylary phloem) occur in peduncles, inflorescence axes, pedicels, flowers, and fruits of most myrtalean taxa (Schmid, 1972b, 1980, for Myrtaceae and Lythraceae; Schmid, unpubl. data and literature survey for other families). However, bicollateral bundles are really histological markers first described for vegetative parts of Myrtales and other orders (Cronquist, 1981; Dahlgren & Thorn, 1984; Metcalfe & Chalk, 1983; van Vliet & Baas, 1984) and then applied to their reproductive parts. The same pertains to vestured pits, which are unreported for myrtalean reproductive structures, but which occur in Lythraceae, Melastomataceae, Myrtaceae, Alzatea (Schmid, unpubl. data). In Myrtales, amphicribral bundles are common, especially in androecia and placentae (Schmid, 1972b, 1980, for Myrtaceae and Lythraceae; Schmid, unpubl. data and literature survey for other families). However, amphicribral bundles seem related to functional, nutritional factors for reasons elaborated elsewhere (Schmid, 1976, 1978). There are no unifying features of floral vasculature for Myrtales (nor for other orders), let alone Myrtaceae. An axile ovular supply (Schmid, 1972a) is most common and clearly basic; the derived transeptal ovular supply (Schmid, 1972a) occurs variously in Myrtaceae, Oliniaceae, Onagraceae, Punicaceae, and Rhynchocalyx of core Myrtales (Eyde, 1981; Schmid, 1972a, 1972b, 1980, unpubl. data and literature survey), as well as in Lecythidaceae sensu lato, Rhizophoraceae

Third ventricle choroid plexus carcinoma

Abstract: Benign and malignant tumors of the choroid plexus in infancy are extremely uncommon. Diagnosis and management of a malignant tumor is described and the literature survey of the problem is presented.

Prenatal diagnosis of Meckel syndrome: case reports and literature review.

Abstract: We report on 2 couples at risk to have Meckel syndrome (MS) offspring. Three pregnancies were monitored by ultrasonography and alpha-fetoprotein (AFP) assay in midtrimester. Of the 2 involving an affected fetus, one was thought to be unaffected. A literature survey was undertaken. Sources of error seem to lie in the heterogeneity of clinical manifestations and the variable onset and rate of progression of clinical components of MS and limitations in ultrasonographic resolution inherent in the scanner or due to the associated oligohydramnios. The following observations/suggestions are made concerning the prenatal diagnosis of MS: 1) Utilize as many tests as are available. 2) Amniotic fluid AFP is more likely to show significant elevation than serum AFP. 3) Ultrasonography should concentrate on presence of oligohydramnios, small head diameter, cystic mass at the occiput, large kidneys, and absent bladder. 4) Use serial AFP and sonographic examination if findings are initially normal or equivocal.

Agitation Dredging: Lessons and Guidelines from Past Projects

Abstract: : This report is based on a comprehensive literature survey of agitation dredging projects and the field data obtained from a small-scale monitoring study. Twenty-two agitation dredging projects are described from the standpoints of technical performance, environmental effects, and economic results. The projects encompassed seven different categories of agitation dredging equipment and several combinations of physical environment and sediment characteristics. The information gathered from these projects is used to develop a number of general and specific conclusions about agitation dredging and the types of applications for which it is best suited. Several categories of agitation dredging equipment are selected as having the most technical potential. The author recommends that existing agitation dredging technology be improved and standardized and that a comprehensive approach be developed for planning and conducting agitation dredging.

On In-Place Strength of Concrete and Pullout Tests

Abstract: The current status of in-place strength evaluation of concrete is discussed. A literature survey regarding the controversy surrounding the assessment of concrete strength through field-cast laboratory-cured cylinder tests is presented. Inconsistencies associated with the drilling and testing of cores for determining in-place concrete strength are pointed out. On the basis of these arguments, the necessity of developing alternative nondestructive test procedures is emphasized. This is followed by a detailed discussion on the status of the pullout test method as a measure of compressive strength of in-place concrete, which appears to be a potentially feasible nondestructive test procedure. The present paper constitutes a state of the art report on the aforementioned topics and contains appropriate recommendations from the authors.

Pyrotechnic shock: A literature survey of the Linear Shaped Charge (LSC)

Abstract: Linear shaped charge (LSC) literature for the past 20 years is reviewed. The following topics are discussed: (1) LSC configuration; (2) LSC usage; (3) LSC induced pyroshock; (4) simulated pyrotechnic testing; (5) actual pyrotechnic testing; (6) data collection methods; (7) data analysis techniques; (8) shock reduction methods; and (9) design criteria. Although no new discoveries have been made in LSC research, charge shapes are improved to allow better cutting performance, testing instrumentation is refined, and some new explosives, for use in LSC, are formulated.

Floc Strength Measurements Giving Experimental Support for a Four Level Hydroxyde Floc Structure

Abstract: A literature survey about floc structure research is given. In this investigation, hydrolysing metal salts were used during the coagulation-flocculation of very diluted kaolinite suspensions. The different experiments are briefly described and explained. The influence of the kinetic process parameters on the floc strength is used to prove the validity of a four level organisation of hydroxydc floc aggregates. The different levels of organisation are: primary particles, flocculi, flocs and floc aggregates. The bonds between the particles are elastic. The influence of the kinetic process parameters on the floc structure is deduced as well.

The taxonomy, morphology and ecology of some smaller Euastrum species (Conjugatophyceae, Desmidiaceae)

Abstract: A morphological study of a large population of a small Euastrum species from a peat-pit in the Auvergne (France) revealed a very confusing taxonomy. A literature survey disclosed a gradual change in the concept of Euastrum sublobatum Breb. in Ralfs by successive authors. The original diagnosis and illustrations are considered inadequate. Because no type material seems to have been preserved, it is proposed to reject E. sublobatum as a “nomen dubium” and to recognize the taxa E. brevisinuosum (Nordst.) stat. nov. and its variety E. brevisinuosum var. dissimile (Nordst.) comb. nov. Some of the forms from the population were rather similar to E. elobatum (Lund.) Roy, while others in front view resembled E. crispulum (Nordst.) W. & G. S. West. The large number of intermediate forms gave reason to unite both species into E. elobatum. Because morphologically simpler forms were found, E. elobatum is considered a highly polymorphic species. The diagnosis is emended, and the observed polymorphism is discussed. In ...

Contemporary trends in group psychotherapy: a literature survey.

Abstract: Group psychotherapy in the 1980s is a dynamic discipline characterized by increasingly refined techniques, expanded applicability, and greater rigor in evaluating outcome. The author provides a brief history of group therapy during the past three decades and then surveys the current literature in the field to link some past trends with recent developments. He concentrates on group therapy for borderline and narcissistic patients, physically ill patients, geriatric patients, chronic psychiatric patients, and patients with sexual and marital problems. Recent innovations in facilitating entry into groups, reducing dropouts, and ensuring meaningful group experiences are also discussed.