Showing papers by "Monash University published in 1987"
TL;DR: The systematic variation within a set of data, as represented by a usual statistical model, may be used to encode the data in a more compact form than would be possible if they were considered to be purely random.
Abstract: SUMMARY The systematic variation within a set of data, as represented by a usual statistical model, may be used to encode the data in a more compact form than would be possible if they were considered to be purely random. The encoded form has two parts. The first states the inferred estimates of the unknown parameters in the model, the second states the data using an optimal code based on the data probability distribution implied by those parameter estimates. Choosing the model and the estimates that give the most compact coding leads to an interesting general inference procedure. In its strict form it has great generality and several nice properties but is computationally infeasible. An approximate form is developed and its relation to other methods is explored.
556 citations
460 citations
Book•
24 Apr 1987TL;DR: In this article, the structure of magnetic materials and their properties are discussed, including the electrical resistivity of simple metals and alloys, as well as magnetic and nearly magnetic alloys.
Abstract: 1. Basic concepts 2. Atomic configuration of an alloy 3. The structure of magnetic materials 4. Electrons in simple metals and alloys 5. Electrical resistivity of simple metals and alloys 6. Non-simple, non-magnetic metals and alloys 7. Magnetic and nearly magnetic alloys 8. Other phenomena Appendices References Index.
430 citations
TL;DR: Three proteins (31, 35 and 39 kDa) with inhibin-like activity have been isolated from bovine follicular fluid with identical NH2-terminal amino acid sequences and their ability to suppress FSH cell content by pituitary cells in culture are 5-10% of bovines 31 kDa inhibin.
355 citations
TL;DR: It is concluded that circulating inhibin is detectable throughout the normal menstrual cycle and in the late follicular phase, inhibin levels rise in parallel with estradiol, consistent with the concept that both are products of the maturing follicle.
Abstract: Serum inhibin concentrations were measured daily by RIA in six normal women throughout one menstrual cycle. The RIA was specific for inhibin, and inhibin subunits and related proteins cross-reacted minimally in it. In the early to midfollicular phase, inhibin levels changed little, while in the late follicular phase, inhibin levels rose, in parallel with estradiol (r = 0.43; P less than 0.05; n = 22), to a peak level of 714 (407-1267) U/L (geometric mean +/- 67% confidence limits) coincident with the midcycle LH and FSH surges. An inverse relationship was found between serum inhibin and FSH during the mid- to late follicular phase (r = 0.42; P less than 0.01; n = 45). Inhibin levels rose further during the luteal phase to a peak level of 1490 (1086-2028) U/L 7-8 days after the LH surge, and they correlated positively with serum progesterone (r = 0.76; P less than 0.001; n = 49) and inversely with serum FSH (r = 0.43; P less than 0.01; n = 49) throughout the luteal phase. We conclude that 1) circulating inhibin is detectable throughout the normal menstrual cycle; 2) in the late follicular phase, inhibin levels rise in parallel with estradiol, consistent with the concept that both are products of the maturing follicle; 3) in the luteal phase, the profile of inhibin suggests that it is a secretory product of the corpus luteum; and 4) the inverse relationship between inhibin and FSH in the follicular phase is consistent with the inhibin hypothesis, while at midcycle there is loss of the inhibitory effect of inhibin on FSH secretion. The inverse relationship between FSH and inhibin during the luteal phase suggests a hitherto unsuspected role for inhibin in the feedback regulation of FSH secretion.
313 citations
TL;DR: Both salivary melatonin concentrations and urinary 6‐hydroxymelatonin sulphate excretion rates are reliable indices of serummelatonin concentrations, providing two convenient, non‐invasive techniques for monitoring melatonin circadian rhythmicity.
Abstract: Although there is a circadian rhythm in blood melatonin concentrations in humans, the problems associated with frequent blood collection limit the use of this rhythm in the investigation of the circadian system and in the diagnosis and treatment of chronobiological disorders. Therefore, to establish a convenient, non-invasive technique for monitoring melatonin circadian rhythmicity, we compared the melatonin concentrations in blood samples collected from five subjects every 2-4 h over a 26 h period, with the melatonin concentrations in saliva samples and with the total amount of 6-hydroxymelatonin sulphate excreted in the urine during 2-h periods. There was significant correlation between serum and salivary melatonin concentrations (r = 0.81, P less than 0.001), and between serum melatonin concentrations and 6-hydroxymelatonin sulphate excretion rates (r = 0.72, P less than 0.001). The results demonstrate that both salivary melatonin concentrations and urinary 6-hydroxymelatonin sulphate excretion rates are reliable indices of serum melatonin concentrations. These measurements, in combination with frequent sample collection, provide two convenient, non-invasive techniques for monitoring melatonin circadian rhythmicity.
177 citations
01 Apr 1987
158 citations
TL;DR: It is demonstrated that most tripronuclear human oocytes have an altered cleavage pattern at the first cleavage division, that most oocytes do not develop into triploid embryos, and that a correlation exists between the pattern of the first Cleavage division and the subsequent karyotype of these embryos.
Abstract: Between 1 and 4% of human oocytes fertilized in vitro are tripronuclear. It has been reported that these tripronuclear oocytes can develop to grossly normal-appearing morulae and that chromosomally, these embryos could be triploid, diploid, or severely depleted. The etiology and proportion of apparently diploid and aneuploid embryos deriving from tripronuclear human oocytes is unknown. This study provides evidence for the first time that most (18 of 29) tripronuclear human oocytes cleave directly to 3-cells at the first cleavage division. These embryos have a severely abnormal (but not triploid) chromosomal complement. Furthermore, some (4 of 29) tripronuclear human oocytes cleave to 2-cells plus an extrusion, and these embryos are diploids, whereas some (7 of 29) cleave to 2-cells, and these embryos are triploid after the first cleavage division. These findings demonstrate that most tripronuclear human oocytes have an altered cleavage pattern at the first cleavage division, that most tripronuclear human oocytes (76% in this study) do not develop into triploid embryos, and that a correlation exists between the pattern of the first cleavage division and the subsequent karyotype of these embryos. Insight into the mechanisms by which these oocytes fail to develop into triploid embryos is also provided.
139 citations
Journal Article•
TL;DR: Serum levels of relaxin in normal and special-interest pregnancies using an homologous radioimmunoassay for human relaxin were higher than those reported in studies using heterologous assays, but the trend in serum levels was similar.
130 citations
01 Jun 1987
TL;DR: In this article, the authors show that the existence of relative-income effects may mean that the optimal level of expenditure on public goods may be higher than indicated by using E MRS = MRT and that the suboptimality of the traditional formula is due to the pre-existence of relative income effects, not due to possible changes in relative incomes created by the public exenditure or the financing of it.
Abstract: depends not only on his absolute income but also on his income relative to that of others) and the issue of the appropriate level of public expenditure have both attracted considerable attention.2 However, to my knowledge, the implication of the former on the latter has never been discussed. This paper shows that the existence of relative-income effects may mean that the optimal level of expenditure on public goods may be higher than indicated by using E MRS = MRT. To avoid possible misunderstanding, it may be noted that the suboptimality of the traditional formula is due to the pre-existence of relative-income effects, not due to possible changes in relative incomes created by the public exenditure or the financing of it. That public finance and expenditure may entail a redistribution of income is well-known. Thus, to concentrate on the relationship between (pre-existent) relative-income effects and the optimal level of public expenditure, let us
125 citations
TL;DR: Livedo reticularis may be a cutaneous marker for the later development of important systemic events in systemic lupus erythematosus and the recognized association of anticardiolipin antibodies with thrombotic events suggests a possible pathogenetic role.
Abstract: • Seventy-eight consecutive patients with systemic lupus erythematosus were assessed for the presence of livedo reticularis. The possible association of livedo reticularis with other clinical and laboratory features including anticardiolipin antibodies was explored. Thirty-eight patients had livedo reticularis. Four cases were severe, 11 moderate, and 23 mild. There was a statistically significant association between the combined moderate and severe livedo reticularis group and elevated levels of anticardiolipin antibodies. The recognized association of anticardiolipin antibodies with thrombotic events suggests a possible pathogenetic role. The presence or history of central nervous system disease, renal disease, vasculitis, or lupus inhibitor was significantly associated with the moderate and severe livedo reticularis group. Livedo reticularis may be a cutaneous marker for the later development of important systemic events in systemic lupus erythematosus. ( Arch Dermatol 1987;123:596-600)
TL;DR: It is suggested that the administration of PS enhances the toxicity of AMNS on the glomerulus and readily produces progressive FSGS in rats resulting in the end-stage renal disease.
TL;DR: An analysis of the times to recurrence revealed that half of the lung recurrence, were clinically obvious within 32 months for rectal tumors and 34 months for colonic, compared to 22 and 21 months, respectively, for liver recurrences, excluding those with other distant metastases.
Abstract: A total of 1578 patients were treated with potentially curative surgical resection for colon and rectal cancer by one surgeon from 1950 to 1982. Follow-up revealed that 117 (11.5 percent) of 1013 patients with rectal carcinoma eventually presented with clinical evidence of pulmonary recurrence, with or without evidence of spread elsewhere; the corresponding figures for the colon were 20 (3.5 percent) of 565 (P less than 0.001). An analysis of the times to recurrence revealed that half of the lung recurrences were clinically obvious within 32 months for rectal tumors and 34 months for colonic, compared to 22 and 21 months, respectively, for liver recurrences, excluding those with other distant metastases. The slower recurrence rate and the longer survival in patients with recurrences in the lung compared to the liver were statistically significant only for rectal primaries (P less than 0.02 and P = 0.001, respectively). Sixteen patients underwent surgery with curative intention for lung recurrences; four of these remain alive at two, six, 11, and 15 years, and one patient was free of recurrence when he died from other causes 15 months after surgery. The conditional probability survival rate for the 16 patients was 38 +/- 13 percent at five years after recurrence operation.
Journal Article•
TL;DR: It is suggested that exaggerated neurogenic inflammatory responses in patients with fibrositis syndrome reflect increased activity of polymodal nociceptors of unmyelinated primary afferent nerves, which may also contribute to the pain and tenderness experienced by these patients.
Abstract: Mechanically induced vasodilatation or flare on the skin, known as dermatographia, is a common clinical observation in fibrositis syndrome and is thought to be a neurogenically mediated axon reflex response. In our study, mechanically and chemically induced flares were quantitated in 13 patients with fibrositis syndrome and 14 control subjects. There was a reduced threshold for chemically induced flare response and the area of flare was greater in patients compared to controls, although there was a wide range of responses in both groups. There was also a significant positive correlation between mechanically and chemically induced flares, and the number of tender points in all subjects correlated with the size of the chemically induced flare. We suggest that exaggerated neurogenic inflammatory responses in patients with fibrositis syndrome reflect increased activity of polymodal nociceptors of unmyelinated primary afferent nerves. This increased receptor activity may also contribute to the pain and tenderness experienced by these patients.
01 Dec 1987
TL;DR: In this paper, sexual discrimination in invitation to job interview was tested by a controlled experimental method of send ing carefully-matched pairs of letters in response to newspaper adver tisements-one from a female and one from a male applicant.
Abstract: Sexual discrimination in invitation to job interview was tested by a controlled experimental method of send ing carefully-matched pairs of letters in response to newspaper adver tisements-one from a female and one from a male applicant. On 363 of the occasions, when invitations were issued, the applicants were trea ted equally, but there were 144 occasions of differential treatment. Females encountered discrimination 40 percent more frequently than ma les. Discrimination against females was statistically significant for the data in aggregate and for two of the seven occupations involved- gardener and computer analyst-programmer. Copyright 1987 by Blackwell Publishers Ltd/University of Adelaide and Flinders University of South Australia
TL;DR: In this article, it was shown that the dominant vortex is generated largely as a component of cross-stream vorticity at the boundary, shed as a shear layer from the body, and turned inertially by the flow to form trailing vortices.
Abstract: The generation of trailing vortices in the wakes of surface-mounted obstacles at moderate Reynolds numbers is examined by channel-flow experiments and numerical simulation. A skew-mounted obstacle generates a single concentrated trailing vortex, together with weak streamwise vorticity of opposite sense extending to considerable distances on either side and zero gross circulation across the whole stream. Cross-stream-symmetrical obstacles (having a streamwise plane of symmetry normal to the plane surface) generate one or more nested vortex pairs, usually of alternate sense, of which one pair is normally dominant. The sense of rotation of the dominant vortex pair depends on both the shape of the obstacle and its depth relative to that of the boundary layer. Obstacles that divide the stream laterally produce dominant vortex pairs with a central downwash, whereas those lifting the flow predominantly over their crests produce dominant vortex pairs with a central upwash. It is argued that the vorticity of the dominant trailing vortices is generated largely as a component of cross-stream vorticity at the boundary, shed as a shear layer from the body, and turned inertially by the flow to form trailing vortices. It should also be emphasized that the dominant trailing vortex or vortex pair is generally embedded in a weak distribution of trailing vorticity of opposite signs, but with net circulation comparable with that of the dominant core.
TL;DR: This chapter discusses the most common types of options-those on common stocks, which play a central role in modern financial practice and complex trading strategies are involved.
Abstract: Options are contracts whose value is contingent upon the value of underlying assets. We will focus on the most common types of options-those on common stocks. A call option gives owners the right to buy (exercise the option) a fixed number of shares at a fixed (exercise/strike) price until a certain (maturity/expiration) date. Conversely, aput option gives owners the right to sell shares at a fixed price. Option contracts are usually purchased in lots of 100 shares. Individuals creating or issuing options are known as sellers/writersand purchasers as holders/buyers-of options. For example, a call option on \"XYZ Jan 50\" at a cost of $800 will give buyers the right to purchase 100 shares of XYZ at $50 a share until January 18, 1988. At any time before this, holders can (1) sell the call at current market price, (2) exercise it by paying $5000 for 100 shares of XYZ, or (3) do nothing. If holders don't exercise the call by January 18, then it will either expire (worthless because XYZ is below $50) with a loss of $800 or, if XYZ is above $50 (say at $60), it will generate a profit of (6050)*100800 = $200. Option trading involves complex combinations of options together with shares, bonds, and other options.\" 2 For example, a butterfly consists of buying two calls-one at a lower strike price and one at a higher strike price-and of selling two calls at a middle strike price. While loss is limited if the stock moves by a large amount, a profit is made if the share stays around the middle strike price. The following features make option trading an interesting domain for expert system applications: * Options play a central role in modern financial practice; * Complex trading strategies are involved; * Returns are contingent on future, uncertain market states-presenting many possibilities for large portfolios; * Traders use heuristic and ad hoc techniques widely, basing their theory on many assumptions-assumptions often violated in practice; * Valuation techniques frequently involve significant numerical computation; and
Journal Article•
TL;DR: The results suggest that the reduced response of capsaicin-treated animals to an antigenic stimulus is due to an effect of Capsaicin on the SP-containing primary afferent nerves rather than a toxic effect of capsicin onThe immune system.
Abstract: The undecapeptide substance P (SP) contained in primary afferent nerves is thought to mediate that part of the neurogenic inflammatory response consisting of vasodilation and plasma extravasation. This response is diminished in rats pretreated as neonates with the neurotoxin capsaicin. It is not known whether primary afferent nerves influence cellular responses of the immune response to antigenic stimulation. Using 6- to 12-wk-old Sprague-Dawley rats pretreated as neonates with capsaicin, we examined the regional lymph node response to a s.c. antigenic stimulus of sheep red blood cells. The number of cells secreting antigen-specific antibody in these animals was reduced by more than 80% using direct and indirect plaque assay methods. The reduced antibody response in capsaicin-pretreated animals was reversed by a s.c. infusion of SP given over a 4-hr period at the injection site immediately after antigen stimulation. This response had a threshold at approximately 1.0 X 10(-5) M SP. SP1-7 (1.0 X 10(-5) M) was without effect but an infusion of SP5-11 (1.0 X 10(-5) M) reversed the effects of capsaicin treatment indicating a carboxyl-terminal effect of SP. The results suggest that the reduced response of capsaicin-treated animals to an antigenic stimulus is due to an effect of capsaicin on the SP-containing primary afferent nerves rather than a toxic effect of capsaicin on the immune system.
TL;DR: The results indicate that, in the C-57 black mouse, MPTP causes a depletion of striatal dopamine without causing nigral cell loss or axon swelling as is observed with other experimental treatments such as 6-hydroxydopamine.
TL;DR: In this paper, the authors measured serum inhibin in 19 women undergoing ovulation induction within an in vitro fertilization program, and found that inhibin rose during the luteal phase to reach a peak (2.5 U/ml) 6 days after oocyte retrieval; it then fell to undetectable levels by day 14.
TL;DR: It is argued that the models of lexical access developed for the written form are also appropriate for speech, provided that the authors allow for obvious differences due to the physical characteristics of speech signals.
TL;DR: Inositol-(l,3,4)-trisphosphate was not detected in heart preparations, suggesting unusual metabolism of inositol)-l,4,5-trisPhosphate in heart tissue, and these data are consistent with the hydrolysis of phosphatidylinositol-4-5-bisphosphates yielding inositl-4,4- Trisph phosphate.
Abstract: Receptor-stimulated phosphatidylinositol turnover has been studied in isolated, perfused, [3H]inositol-labelled rat hearts by measuring accumulation of inositol phosphates in the presence of lithium chloride. Inositol phosphate accumulation was stimulated by norepinephrine (3 X 10(-5) M) and carbachol (10(-3) M), the increases averaging from 931 +/- 59 (n = 6, mean +/- SEM, cpm/g heart) to 4,165 +/- 609 (n = 6, p less than 0.01) for norepinephrine and to 1,853 +/- 354 (n = 6, p less than 0.05) for carbachol. The norepinephrine stimulation was antagonized by prazosin (10(-7) M) but not by propranolol (10(-7) M), indicating mediation via alpha 1-adrenoceptors. The carbachol stimulation was antagonized by atropine (10(-7) M). The stimulation by norepinephrine was significantly higher in right atria (837 +/- 151 to 6,614 +/- 1,210, n = 6, cpm/g tissue) than in other regions of the heart. Both norepinephrine and carbachol stimulated the formation of inositol monophosphate, inositol bisphosphate, and inositol trisphosphate with norepinephrine stimulation being detected as early as 15 seconds. Furthermore, the inositol trisphosphate was identified as the -1,4,5 isomer by anion exchange high-performance liquid chromatography. These data are consistent with the hydrolysis of phosphatidylinositol-(4,5)-bisphosphate yielding inositol-(1,4,5)-trisphosphate. Inositol-(1,3,4)-trisphosphate was not detected in heart preparations, suggesting unusual metabolism of inositol-(1,4,5)-trisphosphate in heart tissue.
TL;DR: Under certain assumptions, necessary and sufficient conditions for a recursive structure to be Δ 0 α -categorical are obtained and these results may be applied, for example, to superatomic Boolean algebras.
TL;DR: Morbidite du cancer non melanotique, mortalite, etiologie, relation entre keratose solaire et cancer cutane non melanOTique.
Abstract: Morbidite du cancer non melanotique, mortalite, etiologie, relation entre keratose solaire et cancer cutane non melanotique
TL;DR: The concentration of immunoreactive inhibin in serum was measured in three pregnant women with premature ovarian failure involved in a donor oocyte in‐vitro fertilization programme indicating that the maternal ovary does not contribute significantly to inhibin secretion during pregnancy.
Abstract: SUMMARY
The concentration of immunoreactive inhibin in serum was measured in three pregnant women with premature ovarian failure involved in a donor oocyte in-vitro fertilization programme. Inhibin was not detectable in peripheral serum prior to conception but rose within 2-4 weeks of embryo transfer, whereafter levels rose gradually during pregnancy ( 20 weeks 2.28 U/ml (1.42-3.67), P < 0.01; geometric mean ± 67% confidence interval) and were similar to those observed in 24 normal pregnant women. hCG rose in parallel with inhibin during early gestation, but declined after 3 months. FSH levels were elevated before conception and were suppressed during pregnancy. In conclusion (i) immunoreactive inhibin is detectable from early gestation in women with no endogenous ovarian function indicating that the maternal ovary does not contribute significantly to inhibin secretion during pregnancy; (ii) the trophoblast is the likely source of inhibin during pregnancy; (iii) the regulation of hCG and inhibin secretion differs throughout gestation; and (iv) inhibin may have a role in FSH regulation during pregnancy and/or a local role within the feto-placental unit.
TL;DR: It is concluded that in the late gestation fetal sheep, elongation of the appendicular skeleton is under some direct pituitary control whereas appendicular maturation exhibits some dependence on circulating T4 concentrations.
Abstract: The role of the pituitary gland in the regulation of skeletal growth and plasma insulin-like growth factor (IGF)-I and IGF-II concentrations in the late gestation sheep fetus has been studied. Singleton fetuses were either hypophysectomized (n = 14) or sham operated (n = 8) between days 110 and 125. Fetal and maternal blood samples were collected three times weekly through the remainder of gestation. In some hypophysectomized fetuses (HXT4 group, n = 4), T4 was administered (100 micrograms L-T4/day) to overcome the hypothyroidism caused by hypophysectomy. The other hypophysectomized fetuses received no replacement therapy (HXNR group, n = 10). Six HXNR fetuses were allowed to remain in utero post term and were killed at day 163 of gestation. All other animals were killed at day 147. All values are group means +/- SE. Hypophysectomized fetuses had significantly shorter limbs and long bones and delayed osseous maturation at term compared to sham controls. Plasma free T4 concentrations in HXT4 fetuses were not significantly different from those measured in sham fetuses (P greater than 0.05). Bone maturation at term was normal in HXT4 fetuses although there was no improvement in limb or bone elongation. Retention of hypophysectomized fetuses in utero until 16 days past term yielded fetuses which were heavier than controls but whose limb and bone lengths were no greater than hypophysectomized fetuses killed at term. Osseous maturation was appropriate for term in five of the six postterm hypophysectomized fetuses. The plasma IGF-I and IGF-II concentrations were not significantly affected by hypophysectomy, hypophysectomy with T4 replacement, gestational age, or prolonged gestation. The plasma IGF-I concentrations in the sham, HXNR, and HXT4 fetuses were 35.4 +/- 6.6, 28.2 +/- 3.0, and 34.4 +/- 1.7 ngeq human (h)IGF-I/ml, and the IGF-II concentrations were 656.3 +/- 59.2, 635.3 +/- 56.3, and 645.5 +/- 71.9 ngeq hIGF-II/ml, respectively, and remained within these ranges throughout the experiment. Fetal IGF-I concentrations were significantly lower than mean maternal IGF-I concentrations (88.0 +/- 6.8 ngeq hIGF-I/ml, P less than 0.05), and fetal IGF-II concentrations were significantly higher than mean maternal IGF-II concentrations (362.4 +/- 24.0 ngeq hIGF-II/ml, P less than 0.05). We conclude that in the late gestation fetal sheep, elongation of the appendicular skeleton is under some direct pituitary control whereas appendicular maturation exhibits some dependence on circulating T4 concentrations.(ABSTRACT TRUNCATED AT 400 WORDS)
TL;DR: In this paper, a reanalysis of vibration-rotation spectral data of formamide using the semi-rigid-bender technique adopted for unsymmetrical 1 large-amplitude motions (LAM) reveals that formamide has a very shallow single-minimum inversion potential.
TL;DR: Both contiguous and independent insertions of IS256 into the staphylococcal chromosome have been observed, the latter suggesting that the element may play a role in molecular rearrangements of the genome.
Abstract: SUMMARY: Resistance to the aminoglycosides gentamicin (Gmr), tobramycin (Tmr) and kanamycin (Kmr) in strains of Staphylococcus aureusisolated in Australia is mediated by the transposon Tn4001. The 1·35 kb inverted repeat of this transposon exhibits many of the characteristics of an insertion sequence and has consequently been designated IS256. Tandem duplication of IS256 contiguous with Tn4001 results in an increase in the level of GmrTmrKmr, thereby implying that the element possesses strong promoter sequences. Both contiguous and independent insertions of IS256 into the staphylococcal chromosome have been observed, the latter suggesting that the element may play a role in molecular rearrangements of the genome.
TL;DR: The Nabarlek mine as mentioned in this paper is a high-grade uranium mine with a prominent reverse fault, which is part of a larger zone of reverse faulting and is associated with a small desilicification zone within, and superimposed on, this larger envelope.
Abstract: The Nabarlek deposit is an unusually high-grade uranium orebody (1.84% U 3 O 8 , 12,000 metric tons) hosted by amphibolite and semipelitic schist of lower Proterozoic age. It is unusual in the Alligator Rivers uranium field in being hosted by amphibolite. The disposition of the ore is controlled by a prominent reverse fault, which is part of a larger zone of reverse faulting. The fault zone is nearly perpendicular to prominent metamorphic S 2 and S 3 fabrics; a geometry which might enhance the fluid-rock ratio. A striking feature of the deposit is the extent and intensity of hydrothermal alteration which extends more than 1 km from the ore. Alteration remote from the ore resulted in pseudomorphous replacement of metamorphic biotite, amphibole, and feldspar, under conditions of a low fluid-rock ratio and mass transfer. Ore is associated with a small desilicification zone within, and superimposed on, this larger envelope. The fluid-rock ratio and mass transfer, resulting mainly in silica loss, were high within this interior zone and produced intense pervasive alteration, leading to an assemblage of phengitic white mica, magnesian chlorite, and hematite. Large volumes of fluid were required to effect the massive desilicification (and deposit such a volume of uranium), given the current knowledge of the solubility of quartz and uraninite.Ore deposition (predominantly as uraninite) postdated intense phengitic white mica alteration. Chlorite, however, is the main gangue mineral, possibly reflecting a change in redox conditions accompanying ore deposition. A redox control on ore deposition is supported by the sparse ocurrence of host-rock graphite which evidently participated in CH 4 -forming reactions. Abundant hematite in the alteration halo suggests the presence of an oxidized fluid (log f (sub O 2 ) approx. -35 at 200 degrees C) which was thus suitable for transporting ore-forming quantities of uranium, probably as chloride complexes. Primary mineralization underwent incongruent dissolution to coffinite, in equilibrium with a vanadian illite, kaolinite, and secondary hematite assemblage (residual ore). Weathering of primary and residual ore produced yellow and green secondary uranium minerals, both pseudomorphous after earlier ore types and as crusting of open goethite-lined fractures.
TL;DR: In this paper, an index designed to identify this signal has been computed from the station data, consistent with the greenhouse effect at most of the stations, and the signal is statistically significant over the hemisphere.
Abstract: Radiosonde temperature data from 147 stations in the Northern Hemisphere for the period 1964-85 have been used to investigate recent temperature trends in the troposphere and lower stratosphere. Experiments with atmospheric general circulation models indicate that increased concentrations of greenhouse gases in the atmosphere will lead to reduced temperatures in the stratosphere as well as increased temperatures in the troposphere. An index designed to identify this signal has been computed from the station data. This index has positive trend at most of the stations, consistent with the greenhouse effect. Over the hemisphere, the signal is statistically significant. However, opposing temperature variations in the troposphere and stratosphere are associated with many other forcing mechanisms and the results cannot be used to identify a specific mechanism.