THE ORIGIN OF DOLOMITE IN THE ASMARI FORMATION (OLIGOCENE-LOWER MIOCENE), DEZFUL EMBAYMENT, SW IRAN

Dolomitisation is an important factor controlling reservoir quality in the Asmari Formation in many producing fields in SW Iran. Dolostones have higher average porosities than limestones. Petrographic and geochemical studies have been used to determine the causes of Asmari dolomitisation at the Bibi Hakimeh and Marun fields and at the Khaviz anticline. The formation is generally characterized by a large‐scale trend of upward‐decreasing accommodation. Basal strata were deposited under relatively open‐marine, high‐energy conditions, whereas the Middle to Upper Asmari succession was deposited in relatively protected settings with more frequent evidence of exposure and evaporitic conditions. There is a general upward increase in the abundance of both anhydrite (occurring as nodules and cement) and dolomite. Two main types of dolomite fabric are recognised, reflecting the textures of the precursor limestones: (1) finely crystalline pervasive dolomite (commonly <20μ) replacing mud‐rich facies; and (2) combinations of finely crystalline replacive dolomite and surrounding areas of coarser dolomite cement (crystals up to 100μ) in grain‐supported facies. Fluid inclusion data indicate that finely crystalline dolomites formed at low temperatures (ca. <50°C), while the coarser dolomite formed at higher temperatures (50–;140°C). Whole rock‐carbonate oxygen and carbon isotope analyses of pure dolostone samples show no apparent correlation with either depositional or diagenetic textures: δ¹⁸O is generally 0 to 2.7‰ PDB, and δ¹³C is ?1 to 4‰ PDB. The importance of evaporated seawater to Asmari dolomitisation is indicated by the ubiquitous occurrence of felty‐textured anhydrite nodules in dolostone beds and the presence of high‐salinity fluid inclusions in dolomite. The derivation of dolomitising fluids from contemporaneous seawater is supported by the general correspondence between age estimates derived from the strontium isotope composition of anhydrites and dolomites and those derived from stratigraphic considerations. This suggested synsedimentary dolomitisation. Dolomitisation of the upper half of the Asmari Formation may have occurred as a result of two syn‐sedimentary mechanisms: (1) by the reflux of evaporative brines concentrated in shallow lagoons or sabkhas, through immediately underlying strata (mainly during highstands); and (2) by the flushing of platform‐top carbonates by basinal evaporated waters during lowstand/early transgression. Continued dolomitisation during deeper burial is supported by the presence of high‐temperature fluid inclusions and iron‐rich crystal rims. Dolomite within the lower part of the Asmari Formation probably mostly formed during burial as a result of compaction of, and fluid exclusion from, the underlying Pabdeh marls and shales.     

The HLA A1-B8 haplotype extends 6 Mb beyond HLA-A: associations between HLA-A, B, F and 15 microsatellite markers

Ornithodoros (Alectorobius) amblus Chamberlin 1920 specimens were collected from a seagull (Larus spp.) nest in northern Chile. This reports the occurrence of this species outside Peru. The biology of 79 specimens reared under laboratory conditions at 27 degrees C, 75-80% RH, and total darkness was determined. A 13% mortality rate from larval to adult was observed. Larval ticks were fed on chicks, Gallus gallus domesticus; and nymphs and adults were fed on chickens. We recorded the number of eggs per female per gonotrophic cycle and the mean duration of the periods of preoviposition, oviposition, and incubation. The total duration of their life cycle ranged from 111 to 239 d, depending on the number of molts. Males were found after the 4th molt, and after the 5th molt the proportion of females was greater than that of males or remaining nymphs. The feeding period of larvae was 4-6 d, N1 nymphs do not feed. The N2-N6 nymphs, males and females, had a 10- to 60-min feeding period. From N2 on, there was emission of coxal fluid while on the host and during or immediately after feeding.     

Percentage discounts, initial price, and bargain hunting: A heuristic-systematic approach to price search behavior.

Consumer decisions concerning price search were investigated using the heuristic-systematic model of social judgment (S. Chaiken, A. Liberman, & A. H. Eagly, 1989). Consumers used the size of the percentage discount as a heuristic cue to help decide whether a better price was likely to be available elsewhere. However, as predicted, participants relied on this cue only when the initial base price of the item was low. In contrast, search was continued despite the offer of a large percentage discount when consumers were shopping for items that were relatively expensive. This finding was attributed to the higher potential costs associated with missing a better price when consumers were shopping for more expensive items. In general, the heuristic-systematic model proved to be a useful way to characterize price search decisions. It was also suggested that these findings might be useful in explaining some conflicting results in the price search literature. Implications for behavioral price theories are also discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of anxiety on inferential reasoning task performance.

Three experiments were conducted in which high anxiety and low anxiety subjects were required to construct inferences. In Experiment 1 there was no anxiety-related performance deficit when inferring a necessary anaphoric relation, a process argued to be automatic. Experiments 2 and 3 involved the verification of unnecessary inferences, a process argued to involve the utilization of the working memory system. In both Experiments 2 and 3 there was an anxiety-related performance deficit. The results are consistent with a working memory-oriented account of anxiety-related performance effects, as deficits were restricted to capacity-demanding tasks. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Nature of HLA-associated predisposition to childhood acute lymphoblastic leukemia

A molecular analysis was carried out in 63 sequentially diagnosed childhood acute lymphoblastic leukemia (ALL) patients and 1011 controls to investigate the homozygosity rate for HLA-DR53. HLA-DR53 is associated with acute myeloblastic leukemia at the protein level, and our previous study has shown its association with early-onset chronic myeloid leukemia only in homozygous form at the DNA level. In the present study, the homozygosity rates for DR53 were 17.5 and 13.6% in patients and controls, respectively. Ten of the 11 homozygous patients were boys. In the common ALL group (n = 40), all seven DR53 homozygous patients were boys, and among 19 girls this genotype was not observed (P = 0.006). For males, homozygosity for DR53 revealed a relative risk (RR) of 3.29 (P = 0.008) for common ALL. Five of the 11 relapsed patients were homozygous for DR53. Heterozygous frequencies for HLA-DR53 were not different between patients and controls. Homozygosity for DR53 was associated with a very high relapse rate (45.5 vs 7.7%, P = 0.002, RR = 9.1). These results extended our findings in chronic myeloid leukemia and showed the recessive nature and the male predominance of the interactive HLA influence on the development of childhood leukemia. Molecular mimicry of an HLA-DR53 epitope by oncogenic (retro)viruses or putative susceptibility genes in linkage disequilibrium with HLA-DR53 may be responsible for this association.     

Clinical efficacy and safety of a novel controlled-release morphine suppository and subcutaneous morphine in cancer pain: a randomized evaluation

PURPOSE: A significant number of cancer patients will require an alternate route of morphine administration at some point during their illness. This study compared the clinical efficacy and safety of a novel morphine sulfate controlled-release suppository (MS-CRS) and subcutaneous (SC) morphine in patients with cancer pain. METHODS: Thirty patients with cancer pain were randomized in a double-blind crossover study to MS-CRS every 12 hours or SC morphine every 4 hours for 4 days each, using a 2.5:1 analgesic equivalence ratio. Pain intensity was assessed using a visual analog scale (VAS) and the Present Pain Intensity Index of the McGill Pain Questionnaire. Nausea and sedation were also assessed with a VAS. Evaluations were made by the patient at 8 AM, noon, 4 PM, and 8 PM and rescue morphine consumption recorded. RESULTS: Twenty-three patients completed the study (13 men and 10 women; mean age, 64.0 +/- 2.0 years) and were treated with mean daily MS-CRS and SC morphine doses of 326 +/- 69 mg and 138 +/- 28 mg, respectively. There was a small but significant difference in overall ordinal pain-intensity scores in favor of MS-CRS (0.7 +/- 0.1 v 0.9 +/- 0.1, P = .0459). There were no significant differences between MS-CRS and SC morphine in overall VAS scores for pain intensity (13 +/- 3 v 13 +/- 3 mm), sedation (23 +/- 3 v 25 +/- 4 mm), and nausea (8 +/- 2 v 9 +/- 2 mm). The mean daily rescue analgesic consumption during MS-CRS and SC morphine did not differ significantly (1.2 +/- 0.4 v 1.2 +/- 0.4 doses/d). CONCLUSION: MS-CRS, administered every 12 hours, provides analgesia comparable to SC morphine and represents a reliable, noninvasive alternative method of pain control for patients unable to take oral morphine.     

Glass formation and dormancy in bacterial spores

Summary Differential scanning calorimetry (DSC) and nuclear magnetic resonance (NMR) techniques were used to obtain evidence whether a glassy state exists within fully hydrated dormant Bacillus subtilis spores. DSC thermograms of hydrated dormant spores contained two major transitions; one at ∼60 °C assigned to be associated with the initial 'activation' stage for germination, and the other at ∼120 °C assigned to be associated with the 'inactivation' process (i.e. killing of the spores). The peak at ∼60 °C had characteristics which were all consistent with at least some region of the compartmentalised structure of fully hydrated dormant spores being in a glassy state. Solid (CPMAS) and liquid state (SPMAS) mobility resolved ¹³C NMR spectroscopy studies on the calcium dipicolinic acid (CaDPA) resonances, which are only present in the central protoplast of bacterial spores, showed it to be present in an amorphous solid-like environment. The DSC and NMR results were both found to be consistent with the hypothesis that the dormancy of bacterial spores is due to at least the central protoplast region being maintained in a low moisture content glassy state.     

HLA class I (A, B) and II (DR, DQ) gene and haplotype frequencies in blood donors from Wales

Recent studies have disclosed several oscillations occurring during resting sleep within the frequency range of the classical delta band (0.5-4 Hz). There are at least 3 oscillations with distinct mechanisms and sites of origin: a slow (<1 Hz) cortically-generated oscillation, a clock-like thalamic oscillation (1-4 Hz), and a cortical oscillation (1-4 Hz). The present paper reviews data on these oscillations and the possible mechanisms which coalesce them into the polymorphic waves of slow wave sleep. Data stem from intracellular (over 500 single cell and 50 double impalements) and field potentials recorded from the cortex and thalamus of cats (120 animals) under ketamine and xylazine anesthesia. Other experiments were based on whole night EEG recordings from humans (5 subjects). The frequency of the slow oscillation both in anesthetized animals and in naturally sleeping humans ranged between 0.1 and 1 Hz (89% of the cases being between 0.5 and 0.9 Hz). The slow (<1 Hz) oscillation is reflected in the EEG as rhythmic sequences of surface-negative waves (associated with hyperpolarizations of deeply-lying neurons) and surface-positive K-complexes (representing excitation in large pools of cortical neurons). Through its long-range synchronization, the slow oscillation has the ability to trigger and to group thalamically-generated spindles and two delta (1-4 Hz) oscillations. Finally, it is argued that the analysis of the electroencephalogram should transcend the spectral analyses, by taking into account the shape of the waves and, when possible, the basic mechanisms that generate those waves.     

Fatal heroin 'overdose': a review

The current paper examines critically the literature on deaths attributed to heroin overdose, and examines the characteristics and circumstances of such deaths. In particular, the dominance of the widely held belief that heroin-related fatalities are a consequence of overdose is challenged. Deaths attributed to overdose represented in the literature are typically older, heroin-dependent males not in drug treatment at the time of death. Fatalities involving only heroin appear to form a minority of overdose occasions, the presence of other drugs (primarily central nervous system depressants such as alcohol and benzodiazepines) being commonly detected at autopsy. Furthermore, deaths attributed to overdose are likely to have morphine levels no higher than those who survive, or heroin users who die from other causes. It is concluded that the term overdose is, in many cases, a misleading term, since it implies the same mechanism of death in all cases, an implication that is neither clinically useful nor consistent with published data. Implications for the prevention of heroin-related deaths are discussed.     

Diamagnetic susceptibility changes in apple tissue after bruising

In nuclear magnetic resonance images of bruised apples, the bruised tissue regions appear brighter than intact tissue regions. The cause for the contrast was investigated. The spin-spin relaxation rates (1/T₂) of the bruised regions were found to be greater than those of firm tissue regions ruling out this mechanism as a cause for the contrast. By comparing spin-echo images (with echo delays of 14 ms and 50 ms) with gradient-recalled-echo images (with echo delay of 5.5 ms) it was concluded that the contrast may be attributed to the decrease in the diamagnetic susceptibility variations within the bruised regions as a result of the partial destruction of the cellular structure caused by bruising. Images of a bruised apple were acquired before bruising, immediately after bruising and approximately every 4 h thereafter, and showed that the contrast between bruised and non-bruised regions increased with time.