Showing papers by "University of Alabama published in 1986"
TL;DR: The results indicated that variation throughout the viral genome is extensive and that the envelope gene in particular is most highly variable, and changes were most prevalent within the extracellular region where clustered nucleotide substitutions and deletions/insertions were evident.
829 citations
TL;DR: The marketing concept has been misunderstood and misused over the years as mentioned in this paper and it is not obsolete nor is it the optimal managerial approach to marketing. The marketing concept is restated in a way that m...
Abstract: The marketing concept has been misunderstood and misused over the years. It is not obsolete nor is it the optimal managerial approach to marketing. The marketing concept is restated in a way that m...
588 citations
TL;DR: The repeated isolation from a given individual of only highly related viruses raises the possibility that some type of interference mechanism may prevent simultaneous infection by more than one major genotypic form of the virus.
Abstract: In a study of genetic variation in the AIDS virus, HTLV-III/LAV, sequential virus isolates from persistently infected individuals were examined by Southern blot genomic analysis, molecular cloning, and nucleotide sequencing. Four to six virus isolates were obtained from each of three individuals over a 1-year or 2-year period. Changes were detected throughout the viral genomes and consisted of isolated and clustered nucleotide point mutations as well as short deletions or insertions. Results from genomic restriction mapping and nucleotide sequence comparisons indicated that viruses isolated sequentially had evolved in parallel from a common progenitor virus. The rate of evolution of HTLV-III/LAV was estimated to be at least 10(-3) nucleotide substitutions per site per year for the env gene and 10(-4) for the gag gene, values a millionfold greater than for most DNA genomes. Despite this relatively rapid rate of sequence divergence, virus isolates from any one patient were all much more related to each other than to viruses from other individuals. In view of the substantial heterogeneity among most independent HTLV-III/LAV isolates, the repeated isolation from a given individual of only highly related viruses raises the possibility that some type of interference mechanism may prevent simultaneous infection by more than one major genotypic form of the virus.
570 citations
529 citations
370 citations
TL;DR: It is reported that the production of ACTH and endorphins by leukocytes is indeed induced by synthetic CRF10 and, in turn, suppressed by dexamethasone, suggesting that, as in pituitary cells, the pro-opiomelanocortin (POMC) gene may be expressed and similarly controlled in leukocyte.
Abstract: Corticotropin releasing factor induction of leukocyte-derived immunoreactive ACTH and endorphins
340 citations
TL;DR: The presence of thin-walling, autoinfective oocysts and recycling of type I meronts may explain why a small oral inoculum can produce an overwhelming infection in a suitable host and why immune deficient persons can have persistent, life-threatening cryptosporidiosis in the absence of repeated oral exposure to thick-walled oocyst membrane.
Abstract: Suckling mice were used as a model host to compare the endogenous development of three different isolates of Cryptosporidium: one from a naturally infected calf, one from an immunocompetent human with a short-term diarrheal illness, and one from a patient with acquired immune deficiency syndrome (AIDS) and persistent, life-threatening, gastrointestinal cryptosporidiosis. After oral inoculation of mice with oocysts, no differences were noted among developmental stages of the three isolates in their sites of infection, times of appearance, and duration, morphology, and fine structure. Sporozoites excysted within the lumen of the duodenum and ileum, penetrated into the microvillous region of villous enterocytes, and developed into type I meronts with six or eight merozoites. Type I merozoites penetrated enterocytes and underwent cyclic development as type I meronts or they became type II meronts with four merozoites. Type II merozoites did not exhibit cyclic development but developed directly into sexual forms. Microgamonts produced approximately 16 small, bullet-shaped microgametes, which were observed attaching to and penetrating macrogametes. Approximately 80% of the oocysts observed in enterocytes had a thick, two-layered wall. After sporulating within the parasitophorous vacuole, these thick-walled oocysts passed through the gut unaltered and were the resistant forms that transmitted the infection to a new host. Approximately 20% of the oocysts in enterocytes consisted of four sporozoites and a residuum surrounded only by a single oocyst membrane that ruptured soon after the parasite was released from the host cell. The presence of thin-walled, autoinfective oocysts and recycling of type I meronts may explain why a small oral inoculum can produce an overwhelming infection in a suitable host and why immune deficient persons can have persistent, life-threatening cryptosporidiosis in the absence of repeated oral exposure to thick-walled oocysts.
257 citations
TL;DR: The presence of thin-walled, autoinfective oocysts and the recycling of Type I meronts may explain why chickens develop heavy intestinal infections lasting up to 21 days.
Abstract: The life cycle and morphology of a previously undescribed species of Cryptosporidium isolated from commercial broiler chickens is described. The prepatent period for Cryptosporidium baileyi n. sp. was three days post oral inoculation (PI) of oocysts, and the patent period was days 4-24 PI for chickens inoculated at two days of age and days 4-14 for chickens inoculated at one and six months of age. During the first three days PI, most developmental stages of C. baileyi were found in the microvillous region of enterocytes of the ileum and large intestine. By day 4 PI, most parasites occurred in enterocytes of the cloaca and bursa of Fabricius (BF). Mature Type I meronts with eight merozoites first appeared 12 h PI and measured 5.0 x 4.9 micrometers. Mature Type II meronts with four merozoites and a large granular residuum first appeared 48 h PI and measured 5.1 x 5.1 micrometers. Type III meronts with eight short merozoites and a large homogeneous residuum first appeared 72 h PI and measured 5.2 x 5.1 micrometers. Microgamonts (4.0 x 4.0 micrometers) produced approximately 16 microgametes that penetrated into macrogametes (4.7 x 4.7 micrometers). Macrogametes gave rise to two types of oocysts that sporulated within the host cells. Most were thick-walled oocysts (6.3 x 5.2 micrometers), the resistant forms that passed unaltered in the feces. Some were thin-walled oocysts whose wall (membrane) readily ruptured upon release from the host cell. Sporozoites from thin-walled oocysts were observed penetrating enterocytes in mucosal smears. The presence of thin-walled, autoinfective oocysts and the recycling of Type I meronts may explain why chickens develop heavy intestinal infections lasting up to 21 days. Oocysts of C. baileyi were inoculated orally into several animals to determine its host specificity. Cryptosporidium baileyi did not produce infections in suckling mice and goats or in two-day-old or two-week-old quail. One of six 10-day-old turkeys had small numbers of asexual stages only in the BF. Four of six one-day-old turkeys developed mild infections only in the BF, and sexual stages of the parasite were observed in only one of the four. All seven one-day-old ducks and seven two-day-old geese developed heavy infections only in the BF with all known developmental stages present.
249 citations
TL;DR: In fourteen renal transplant patients converted from cyclosporin to azathioprine for financial reasons renal blood flow was greater and renal vascular resistance lower after conversion, and changes occurred without any change in serum creatinine, suggesting that the renal allograft vasoconstriction induced by cyclospora occurs before evidence of nephrotoxicity.
234 citations
TL;DR: The authors developed a 17-item scale to measure people's sense of community with their city of residence, which was then evaluated for homogeneity and external validity in three studies using telephone interviews on random samples in Alabama and South Carolina.
Abstract: Based on a deductive process, several objective items were developed to measure people's sense of community with their city of residence. An item analysis produced a 17-item scale, which was then evaluated for homogeneity and external validity in three studies using telephone interviews on random samples in Alabama and South Carolina. Of seven hypotheses that were tested, six received support. Results described the scale as internally reliable and unidimensional, and the scale differentiated between people who differed in terms of demographics, home ownership, and civic contributions. Contrary to prediction, the scale did not relate to how long people had lived in their city. Explanations for this were offered and then conclusions were drawn about the potential usefulness of the scale.
207 citations
TL;DR: Intralesional alpha-2 IFN is of benefit in the treatment of a single condyloma; its role in the Treatment of multiple lesions remains to be clarified.
Abstract: We conducted a multicenter double-blind study comparing human recombinant intralesional alpha-2 interferon (IFN) and placebo in 237 patients with the clinical diagnosis of condyloma acuminatum or verruca plantaris. A single wart on each patient was injected with 0.1 mL containing 10(6) IU of IFN, 10(5) IU of IFN, or placebo three times weekly for three weeks, and the response to treatment was followed up for 12 weeks. Among 91 of the 114 patients with condyloma acuminatum who completed the study, complete clearing of the treated wart occurred in 16 (53%) of 30 patients receiving 10(6) IU of IFN compared with six (19%) of 32 receiving 10(5) IU of IFN and four (14%) of 29 receiving placebo. In the group of 100 patients with plantar warts, there was no apparent benefit associated with interferon administration. Seven patients (3%) had treatment discontinued due to adverse reactions. Intralesional alpha-2 IFN is of benefit in the treatment of a single condyloma; its role in the treatment of multiple lesions remains to be clarified. Its role in the treatment of verruca plantaris, where no response was seen, also remains to be clarified.
TL;DR: It is emphasized that bronchiolitis obliterans and usual interstitial pneumonia represent separate and distinct clinicopathologic entities.
Abstract: The clinical, radiographic, and pathologic features were studied in 24 cases of bronchiolitis obliterans and 16 cases of usual interstitial pneumonia, to define better their distinguishing characteristics. Bronchiolitis obliterans had a more acute onset often associated with fever, while the presentation of usual interstitial pneumonia was insidious with dyspnea and cough. The radiographs in usual interstitial pneumonia uniformly showed bilateral interstitial opacities, while they were more variable in bronchiolitis obliterans, with air space densities in 15 and interstitial opacities in nine. Prognosis was considerably better for bronchiolitis obliterans patients. Resolution of disease occurred in nearly half, while no patient with usual interstitial pneumonia recovered. Three individuals with bronchiolitis obliterans (12.5%) died of progressive disease, compared to 10 with usual interstitial pneumonia (62.5%). Pathologically, the lesion in bronchiolitis obliterans affected mainly air spaces in a peribronchiolar distribution, while the changes in usual interstitial pneumonia were mainly interstitial and randomly distributed. The fibrosis in bronchiolitis obliterans was composed of proliferating fibroblasts, compared to collagen deposition in usual interstitial pneumonia. These findings emphasize that bronchiolitis obliterans and usual interstitial pneumonia represent separate and distinct clinicopathologic entities.
TL;DR: In this article, the authors investigated the importance of nonenvironmental benefits for the design of an efficient pollution tax and found that the efficient tax may be higher or lower than that conventionally defined as optimal, and that the net benefit from unrestrained pollution can have important implications for the size of the tax.
TL;DR: In this paper, a 4 ps, 510 nm laser pulse was used to electronically excite toluene solutions of all-trans-β-carotene, canthaxanthin, and β-8'-apocarotenal.
TL;DR: In this paper, a typical upwelling event is analyzed using Dynamic Explorer 1 satellite retarding ion mass spectrometer (RIMS) observations of the low-energy plasma, and energetic ion and local electromagnetic field observations.
Abstract: The characteristics of an upwelling ion source are discussed. A typical upwelling event is analyzed using Dynamic Explorer 1 satellite retarding ion mass spectrometer (RIMS) observations of the low-energy plasma, and energetic ion and local electromagnetic field observations. The RIMS spectrograms of the O(+) ion species, radial and axial head data for O(+), and spin plan O(+) distribution functions are examined. The features of the upwelling observed include: (1) transverse ion heating to temperature of 100,000 K, (2) large outward flows of O(+), (3) enhanced flow of H(+) and He (+), (4) moderately strong field-aligned current sheets, (5) an associated intense eastward convection channel, and (6) strong wave emissions in the range near and below the proton gyrofrequency. The association between the upwelling O(+) signature and auroral current is investigated. Plasma wave and electric field environments are studied and plasma flows and densities are derived. It is noted that the mechanism for ion heating which defines the source region for these polar ion outflows is related to field-aligned currents and an associated auroral convection channel or jet.
TL;DR: Levels of IgA1, IgA2, IgM, and IgG antibodies specific for 10 ubiquitous food and bacterial antigens were examined by radioimmunoassay in the sera of 29 patients with IgA-associated renal diseases and 22 normal individuals and there was no preponderance of one form in either patient or normal groups.
Abstract: Levels of IgA1, IgA2, IgM, and IgG antibodies specific for 10 ubiquitous food and bacterial antigens were examined by radioimmunoassay in the sera of 29 patients with IgA-associated renal diseases and 22 normal individuals. No significant differences were observed between patient and normal groups in the levels of IgA1 antibodies, and IgA2 antibodies were detected in only a few individuals in either group. Minor differences in IgM or IgG antibodies were seen against some antigens. Significant positive correlations between IgA1 and IgG and between IgA1 and IgM antibodies to casein were found in the patient group. Analysis of the molecular form of serum IgA1 antibodies revealed that although the pattern of polymeric and monomeric forms varied between individuals and between antibody specificities, there was no preponderance of one form in either patient or normal groups. Examination of kidney biopsies from 50 patients with IgA-associated renal diseases revealed that IgA1 represented the predominant subclass deposited in the glomerular mesangium; glomeruli from three patients contained both IgA1 and IgA2. Seventy-eight percent of the patients also had deposits of IgM, although IgA and IgM deposits did not always coincide. When IgG was present in glomeruli (45% of patients), the IgG1 subclass predominated. J chain was detectable in glomeruli of only four patients. C3 was detected in glomeruli of 95% of the patients, although the distribution of C3 did not always coincide with that of IgA. Indirect immunofluorescence staining with rabbit antisera to various environmental antigens showed that milk protein antigens could be deposited in association with IgA in the glomerular mesangium.
TL;DR: In this article, the attitudes of 521 teachers in the Tuscaloosa, Alabama City School (82% of the teacher population) toward stuttering were assessed using the Teachers' Perceptions of Stuttering Inventory (TPSI) consisting of five teacher identification questions and 10 attitudinal statements about which teachers are asked to indicate their strength of agreement.
TL;DR: With the exception of pepsin, which was not found until day 16, all of the measured enzymes were present in the digestive tract at the time of first feeding and activities of these enzymes were 25 to 60% of those at day 32.
Abstract: Growth and activities of the digestive enzymes trypsin, chymotrypsin, carboxypeptidase A, α-amylase, and pepsin in striped bass Morone saxatilis were measured from the day before the fish first accepted food (day 4) to near the end of larva development (day 32). Fish were fed either live brine shrimp nauplii Artemia sp. (BSN), heat-killed BSN, or a prepared diet designed to be nutritionally complete with satisfactory physical and palatability properties. The larvae consumed the prepared diet but did not grow and all larvae fed this diet died soon after day 16. Larvae fed live or heat-killed BSN grew satisfactorily but growth of fish fed live BSN was faster (P < 0.05). With the exception of pepsin, which was not found until day 16, all of the measured enzymes were present in the digestive tract at the time of first feeding and activities of these enzymes were 25 to 60% of those at day 32, For the first 12 d, specific activity of the enzymes was not influenced by growth or diet. Near day 16, enzyme...
TL;DR: Channel catfish were stocked in ponds with maximum daily feeding rates of 0, 28, 56, 84, 112, 168, and 224 kg/hectare and strong correlations were obtained between feeding rates and concentrations of DO at dawn, chlorophyll a, chemical oxygen demand, carbon dioxide, and total ammonia nitrogen.
Abstract: Channel catfish (Ictalurus punctatus) were stocked in ponds at 1,200, 4,300, 8,600, 17,300, 26,000, and 34,600 fish per hectare (486, 1,740, 3,480, 7,000, 10,520, and 14,000 fish per acre), and maximum daily feeding rates of 0, 28, 56, 84, 112, 168, and 224 kg/hectare (0 25, 50, 75, 100, 150, and 200 lb/acre), respectively, were established Aeration was applied at 61 kW/hectare (33 horsepower/acre) when dissolved oxygen (DO) concentrations were expected to fall below 2 mg/L Strong correlations were obtained between feeding rates (X) and concentrations (Y) of DO at dawn, chlorophyll a, chemical oxygen demand, carbon dioxide, and total ammonia nitrogen The correlation for DO was negative Net fish production was correlated with feeding rates up to a maximum daily feeding rate of 112 kg/hectare (100 lb/acre) Feed conversion ratios were essentially constant up to a maximum feeding rate of 112 kg/hectare (100 lb/acre) At higher feeding rates, feed conversion ratios increased and fish productio
TL;DR: An extensive set of plasmaspheric measurements from the DE 1 satellite and ionospheric measurements by the DE 2 satellite are presented in this paper. But the analysis is limited to the recovery phase of a magnetospheric storm.
Abstract: An extensive set of plasmaspheric measurements by the DE 1 satellite and ionospheric measurements by the DE 2 satellite are presented. The developments in the ionosphere and plasmasphere during the recovery phase of a magnetospheric storm are described. Isolated profile comparisons are used to indicate some of the structural relations and complexities involving the ionosphere and plasmasphere latitudinal profiles. A transition in the ionospheric electron temperature Te from a relatively smooth profile of low Te at the base of the inner plasmasphere to enhanced and highly structured Te at higher invariant latitudes occurs near or along a plasmaspheric density gradient. Plasmaspheric enhancements of the heavy ions O(+) and O(2+) are often closely aligned with distinct ionospheric Te enhancements.
Journal Article•
TL;DR: The results indicate that NK cells become cytotoxic for noncultured solid tumor cells by a brief contact with rIL 2, and increase cytot toxic activity after culture with ril 2.
Abstract: The ability of NK cells to lyse noncultured solid tumor cells was investigated, and the results were compared with lysis of K562. Purified NK cell fractions separated by either Percoll centrifugation or a cell sorter exhibited higher level of lysis against noncultured melanoma cells than did NK-depleted cell fractions. However, the level of lysis was low (less than 10% lysis). Adding recombinant interleukin 2 (rIL 2) to the 4-hr assay induced significant lysis (more than 10%) of noncultured melanoma cells in 18 of 23 (78%) Percoll-enriched NK cell fractions and seven of 11 (64%) sorted Leu-11a+ cells at an E:T ratio of 80 and 10, respectively. In contrast, only two of 13 (14%) PBMC, five of 17 (29%) Percoll-decreased NK cell fractions, and one of 12 (8%) sorted Leu-11a- cells lysed noncultured melanomas in the presence of rIL 2. rIL 2 induced NK cells to lyse noncultured lung and breast cancer cells, as well as melanoma tumors. Exposure of NK cells to 2000 rad radiation abrogated the rIL 2-induced cytotoxicity against noncultured melanomas. Preculture of PBMC for 18 hr with recombinant interferon-gamma (rIFN-gamma) resulted in a modest level of lysis of non-cultured melanomas by sorted Leu-11a+ cells. Adding rIL 2 to the assay increased the cytotoxic activity in both rIFN-gamma-activated Leu-11a+ and Leu-7+ NK subsets. The level of noncultured tumor lysis correlated well with that of K562 lysis in all of the experiments. Purified NK cell fractions in rIL 2 cultures increased cytotoxic activity against noncultured tumor cells with incubation time for up to 3 days, and the level of NK cell-mediated lysis was dependent on both doses of rIL 2 and length of incubation. In contrast, both NK-depleted and sorted Leu-11a- cells demonstrated very low levels of solid tumor lysis after 3-day cultures with a high dose of rIL 2. Killer cell precursors induced by 3-day cultures of sorted cell fractions with rIL 2 and rIFN-gamma were found in both Leu-11a+ and Leu-7+ NK subsets, but not Leu-4+ or Leu-3a+ T lymphocytes. These results indicate that NK cells become cytotoxic for noncultured solid tumor cells by a brief contact with rIL 2, and increase cytotoxic activity after culture with rIL 2.
01 Jan 1986
TL;DR: Nickel-copper sulfide deposits associated with rocks of komatiitic affinity may be divided into two associations on the basis of host rock composition and ore distribution as mentioned in this paper.
Abstract: Nickel-copper sulfide deposits associated with rocks of komatiitic affinity may be divided into two associations on the basis of host rock composition and ore distribution: (1) stratiform, massive-matrix-disseminated sulfides hosted by cumulate komatiite lava flows (lava conduits), or strata-bound, coarse disseminated sulfides hosted by cumulate komatiite bodies near volcanic vents, and (2) strata-bound, finely disseminated sulfides and more restricted massive sulfides hosted by subvolcanic komatiitic dunites (high-level magma chambers). These deposits represent a continuum in environments of emplacement from distal volcanic through proximal and central volcanic to subvolcanic.
TL;DR: A survey of the literature in the field of affective responsiveness was undertaken by the Affective Response SRIG in order to extract a listing of commonly used words and recommended definitions based upon common usage as mentioned in this paper.
Abstract: ogy associated with this [affective response] area\" (McMullen, 1982). These efforts were presented at a special session titled \"The Affective Experience: A Dialogue,\" and were summarized by Asmus (1982). During the Music Educators National Conference (MENC) National Convention in March 1984, members of the Affective Response SRIG discussed the continuing problems with the use of terminology in the field. It was felt that the terminology was used inconsistently or carelessly, thus contributing to difficulty in communication among members of the profession. It was decided that a survey of the literature in the field of affective responsiveness be undertaken by the SRIG in order to extract a listing of commonly used words and recommended definitions based upon common usage. A proposed strategy was developed. It was presented for feedback at the Southern Division Convention of MENC (Price, 1985) and to the members of the Affective Response SRIG through the April 1985 issue of the Affective Response SRIG Newsletter. This strategy included the methodology to be used, with a listing of specific texts and journals to be surveyed. After feedback, the techniques and listing literature to be surveyed were revised and the survey was begun. An interim glossary, along with the listing of books and journals surveyed to date, was distributed through the September 1985 Affective Response SRIG Newsletter. Included was a request for feedback on additional sources or terminology and modification of definitions. A second interim report was distributed through the January 1986 Affective
TL;DR: It is demonstrated that physiological concentrations of ANG II can elicit receptor-dependent and reversible vasoconstriction of the juxtamedullary nephron microvasculature at both pre- and postglomerular sites.
Abstract: The purpose of this study was to determine the specific renal microvascular segments that are functionally responsive to angiotensin II (ANG II) and other vasoactive hormones. Experiments were performed on juxtamedullary tissue from captopril-treated rats during perfusion with blood at a constant pressure of 110 mmHg. Epifluorescence videomicroscopy was utilized to measure diameters of arcuate and interlobular arteries (ART), mid- (MA) and late- (LA) afferent arterioles, and efferent arterioles (EA). Norepinephrine (700 nM) significantly decreased, and sodium nitroprusside (380 nM) increased, inside diameters of all segments. Topical application of ANG II (0.01 to 1 nM) induced significant reductions in diameters of all vessel segments: ART, 17.5 +/- 2.0%; MA, 19.6 +/- 2.5%; LA, 13.5 +/- 1.5%; and EA, 16.9 +/- 2.7%. The preglomerular response to ANG II was blocked by saralasin (10 microM) and, in most cases, was dose dependent; however, an initial hypersensitivity to low ANG II doses (30% decrease in diameter) was exhibited by 38% of the preglomerular vessels studied. Under these experimental conditions, single-nephron glomerular filtration rate decreased significantly in response to 0.01 nM ANG II exposure. These observations demonstrate that physiological concentrations of ANG II can elicit receptor-dependent and reversible vasoconstriction of the juxtamedullary nephron microvasculature at both pre- and postglomerular sites.
TL;DR: Monthly sensory (taste) analyses of channel catfish Ictalurus punctatus from 11 commercial culture ponds in Alabama during April-October 1983 showed that earthy-musty flavor was the major off-flavor during the summer growing season.
Abstract: Monthly sensory (taste) analyses of channel catfish Ictalurus punctatus from 11 commercial culture ponds in Alabama during April-October 1983 showed that earthy-musty flavor was the major off-flavor during the summer growing season. Geosmin (1,10-trans-dimethyl-trans-(9)-decalol) was found by gas chromatography in detectable amounts, 3.7 to over 200 μg/kg of fish flesh, in 80% of fish having earthy-musty or detritus (pond mud) flavor. Geosmin was not found in fish without these flavors. The geosmin analysis procedure used in this study recovered 68 to 85% of geosmin added to fish flesh, at concentrations ranging from 8 to 32 μg/kg, with relatively high consistency (SD = 2.5–3.3). Reproducibility in analysis of fish with naturally occurring geosmin (6–15 μg/kg fish) was also favorable (coefficients of variation, 100˙SD/mean, 6.9–16.8%). The compound 2-methylisoborneol, found in muddy-flavored rainbow trout Salmo gairdneri, could not be confirmed as an off-flavor compound in channel catfish. The us...
TL;DR: In this article, the authors demonstrate that interspinifex Fe-Ni-Cu sulphide ores formed by thermal erosion of underlying komatiite flows and possibly also sediments, provided proof of thermal erosion.
Abstract: Huppert et al.1 calculated that komatiites flow turbulently, transfer heat efficiently to their substrate, and thus potentially produce thermal-erosion channels in sequences onto which they were erupted. Their suggestion that komatiite-hosted (Kambalda-type2) nickel ores reside in such channels has led to resurgence of interest in volcanic models for ore emplacement3–5 and caused controversy6,7. Such models have important implications, not only to ore-genetic studies but also to interpretation of the geochemistry of komatiites8 and their Sm–Nd systematics9,10. Here we demonstrate that interspinifex Fe–Ni–Cu sulphide ores, which underlie some hanging wall massive sulphide ores at Kambalda the site of one of the world's major nickel deposits, formed through thermal erosion of underlying komatiite flows and possibly also sediments, providing proof of thermal erosion. However, we caution against the general application of thermal-erosion models to the eruption of komatiites. It seems that significant thermal erosion occurred rarely, and only where basal concentrations of highly thermally conductive sulphide liquid were present at the base of localized lava channels. Isotope data11,12 and theoretical considerations13 suggest that the komatiites were contaminated by crustal rocks before eruption, although there is limited evidence that localized contamination, including sulphide assimilation4, may also have occurred below lava channels localized in pre-existing embayments or troughs.
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TL;DR: Nagel as mentioned in this paper argued that it seems irrational to take or dispense credit or blame for matters over which a person has no control, and that if the condition of control is consistently applied, it threatens to undermine most of the moral assessments we find it natural to make.
Abstract: One 'condition of moral judgment' is that matters beyond a person's control cannot bear on what he deserves. For example, to be born in Pakistan cannot make you deserve to fare less well than if you had been born somewhere else. Nor can you deserve credit for winning a lottery through sheer luck, or blame for bleeding when you are cut. Those are all matters beyond your control, and thus beyond your responsibility: a connection so fundamental that Nagel can say 'It seems irrational to take or dispense credit or blame for matters over which a person has no control .... And yet, Nagel also argues, 'If the condition of control is consistently applied, it threatens to undermine most of the moral assessments we find it natural to make.'3 For one thing, says Nagel, we take the consequences of a person's behaviour to bear on just how bad a thing he has done, and thus on how harsh a response he should receive-even though the consequences may be determined by something beyond his control! Consider the driver who roars through a school zone at 70 m.p.h., oblivious to the children darting a few feet from his path. If he is lucky enough to pass through without hitting anyone, he is guilty of reckless driving, and will be criticized accordingly. But what if a child chooses precisely the wrong moment to dash after a ball, and ends up crushed beneath our driver's wheels? Then it will be manslaughter he has committed, a far worse thing to have done, and we will take him to deserve much harsher treatment. What makes the difference, though, is something beyond the driver's control: his luck in what the children do. So here, Nagel would argue, we give luck the very power we deny it can have: the power to make a person deserve harsher or milder treatment. And, says he, we could not stop doing so without abandoning an equally fundamental tenet that those who do more harm deserve harsher treatment than those who do less. Similarly,
TL;DR: The degree to which the O(+) + N2 reaction rate is increased as a result of enhanced vibrational excitation of the N2 molecule in the thermosphere was investigated in this article.
Abstract: The degree to which the O(+) + N2 reaction rate is increased as a result of enhanced vibrational excitation of the N2 molecule in the thermosphere was investigated. It is found that the reaction rate may be sufficiently elevated in summer at solar maximum to decrease the peak O(+) density by a factor of 2, but there is only a small reduction in the winter peak density. Therefore the vibrational excitation of N2 acts to increase the magnitude of the seasonal anomaly. This work emphasizes the need for more laboratory work to clear up uncertainties in some of the key parameters.
01 Jan 1986
TL;DR: In this article, two years of data from Mobile Bay show that subtidal shelf-estuarine exchanges at periods of 2 to 4 days are driven by the cross-shelf along-estuary wind stress.
Abstract: Two years of data from Mobile Bay show that subtidal shelf-estuarine exchanges at periods of 2 to 4 days are driven by the cross-shelf along-estuary wind stress. At periods of 3 to 20 days, coastal Ekman convergence/divergence, driven by the alongshore wind stress, becomes important in driving the exchanges. Such a situation is common to many estuaries around the northern rim of the Gulf of Mexico. At seasonal scales, river runoff becomes important to both the barotropic and baroclinic exchanges.
TL;DR: In this paper, the relationship between the maximal covering problem and the P-median problem is reviewed, and two multiple coverage models, theyaximumexpectedcoverage problem (MECP) and thebackupcoverageproblem (BACOP), are special cases of the vector assignmentP-mediansproblem (VAPMP).
Abstract: The relationship between the maximal covering problem and the P-median problem is reviewed. It is shown that two multiple coverage models, themaximumexpectedcoverageproblem (MECP) and thebackupcoverageproblem (BACOP), are special cases of thevectorassignmentP-medianproblem (VAPMP). This relationship is utilized to solve both MECP and BACOP on test sets from the literature. Computational experience is reported.