Meteoritic Evidence for a Ceres-sized Water-rich Carbonaceous Chondrite Parent Asteroid.

Carbonaceous chondrite meteorites record the earliest stages of Solar System geo-logical activities and provide insight into their parent bodies' histories. Some carbonaceous chondrites are volumetrically dominated by hydrated minerals, providing evidence for low temperature and pressure aqueous alteration1. Others are dominated by anhydrous minerals and textures that indicate high temperature metamorphism in the absence of aqueous fluids1. Evidence of hydrous metamorphism at intermediate pressures and temperatures in carbonaceous chondrite parent bodies has been virtually absent. Here we show that an ungrouped, aqueously altered carbonaceous chondrite fragment (numbered 202) from the Almahata Sitta (AhS) meteorite contains an assemblage of minerals, including amphibole, that reflect fluid-assisted metamorphism at intermediate temperatures and pressures on the parent asteroid. Amphiboles are rare in carbonaceous chondrites, having only been identified previously as a trace component in Allende (CV3oxA) chondrules2. Formation of these minerals requires prolonged metamorphism in a large (~640-1800 km diameter), unknown asteroid. Because Allende and AhS 202 represent different asteroidal parent bodies, intermediate conditions may have been more widespread in the early Solar System than recognized from known carbonaceous chondrite meteorites, which are likely a biased sampling.

Evaluation of measures of technical image quality for intracranial magnetic resonance angiography.

We evaluate three measures of technical image quality for intracranial magnetic resonance angiography (MRA): (1) a two-alternative forced choice (2AFC) evaluation of vessel visibility, (2) vessel-to-background signal-difference-to-noise ratio (SDNR), and (3) observer ranking of the fidelity of vessel morphology compared to that in a gold standard image. The gold standard used for both the 2AFC and ranking measures is intraarterial catheter angiography. These measures are applied to healthy arterial segments. The 2AFC and SDNR measures directly evaluate the visibility of artery segments for which the existence is known from the gold standard images. We argue that (1) 2AFC evaluates the carrier signals on which any vascular disease process is modulated and provides an upper bound on the detectibility of vascular lesions, (2) SDNR is a predictor of 2AFC, and (3) ranking may be used to predict the relative performance of techniques in the detection of vascular lesions.

The association of elder abuse and substance abuse in the Illinois Elder Abuse System.

This article explores the role of abuser substance abuse in 552 cases of substantiated elder abuse in Illinois. When the abuser was identified as having a substance abuse (SA) problem, the type of elder abuse substantiated was more likely to involve either physical or emotional abuse than neglect or financial exploitation. Abusers with SA problems were more frequently men and children of their victims, and less likely to be caregivers. Abuser SA was associated with victim SA. Cases involving abusers with SA problems were more likely to be evaluated by case workers as having a high potential risk for future abuse. Elder abuser case workers should be trained to identify both victim and abuser SA and appropriate intervention strategies.

The Illinois elder abuse system: program description and administrative findings.

In this article we describe the Illinois statewide elder abuse social service program, which is unusual in its comprehensive approach to the assessment and documentation of reported cases of abuse and its extensive data monitoring system. Descriptive information on the number and types of cases of elder abuse reported to the system are presented, along with information on the amount of social work time and administrative effort spent on substantiating abuse reports and providing services. Financial exploitation, emotional abuse, and neglect were the most common types of abuse reported, although emotional abuse was the type most frequently substantiated. The most frequent reasons for case closure were (a) victim entered long-term care, and (b) the workers' assessment that the victim was not at risk for future abuse. A detailed description of the comprehensive assessment and substantiation process is provided.

Central versus peripheral effects on temperature preference and body temperature following alteration of 5-HT in maturing mice.

Experiments were designed to distinguish between central and peripheral effects on temperature preference and body temperature of drugs injected intraperitoneally (IP) in infant mice ranging in age from 3 to 10 days postpartum. These compared a drug restricted to the periphery ("peripheral" drug) with a drug of similar action that reaches the central nervous system (CNS) as well as the periphery. Two different classes of drugs were utilized to test central versus peripheral actions independently with drugs that have different modes of action: 1-aromatic amino acid inhibitors and serotonin receptor antagonists. Although the decarboxylase inhibitor NSD 1015, which reaches the central nervous system from IP injection, can significantly decrease temperature preference (Tpref), the peripheral inhibitor carbidopa had no significant effects on Tpref or on body temperature (Tb). Furthermore, pretreatment with NSD 1015 prevented the elevation of Tpref produced by the serotonin precursor 5-hydroxytryptophan (5-HTP); however carbidopa pretreatment had no effect on the increased Tpref produced by 5-HTP. In other experiments, the peripheral serotonin antagonist BW 501C was not able to prevent elevated Tpref produced by 5-HTP, although the specific 5-HT2 antagonist pirenperone, which reaches the CNS as well as the periphery, blocks the 5-HTP elevation of Tpref. Taking all of these results together, we conclude that the changes in Tb and Tpref following these treatments require a decarboxylase inhibitor or 5-HT antagonist that reaches the CNS. However, the well known and potent peripheral vasoconstrictor action of serotonin requires that peripheral effects of drugs be considered when manipulations are not restricted to the CNS.

Water proton NMR relaxation mechanisms in lung tissue.

The NMR relaxation times T'2, T2, and T1 were measured in isolated rat lungs as functions of external magnetic field B0, temperature, and lung inflation. The observed linear dependence on B0 of the tissue-induced free induction decay rate (T'2)-1 provides independent confirmation of the air/water interface model of the lung. Furthermore, measurements of the Larmor frequency dependence of T1 are consistent with a spin-lattice relaxation rate of the form 1/T1 = A omega -1/2 + B as expected for the case in which the relaxation arises from water-biopolymer cross-relaxation, which should be proportional to the surface area of the lung. This prediction was verified by observations of an approximately linear dependence of 1/T1 on transpulmonary pressure and thus on the lung surface area.

Increased REM sleep in rats selectively bred for cholinergic hyperactivity.

We have examined the sleep profile of the Flinders Sensitive Line (FSL) of rats, which were selectively bred for supersensitive responsivity to an acetylcholinesterase inhibitor (DFP). These animals have an increased density of muscarinic receptors in striatum and hippocampus and display a number of behavioral and neuroendocrine characteristics that may represent a rodent analogue of clinical depression. A continuous 48-hour sleep EEG recording was obtained. Compared to control rats (the Flinders Resistant Line), the FSL rats had selectively more rapid-eye-movement (REM) sleep as a percentage of total sleep time. In addition, the REM sleep latency was significantly shorter and the REM-REM cycle length was significantly faster in the FSL than in the FRL strain. The two strains did not differ in total sleep time, drowsy sleep, or slow-wave sleep. The increased REM sleep in the FSL rats is consistent with the amassed evidence that cholinergic mechanisms selectively promote REM sleep, and suggests that the FSL rats may be useful in understanding the mechanism responsible for short REM latency in depression and narcolepsy.

Maturational age affects pirenperone dose-response pattern.

The effects of the 5-HT2 antagonist pirenperone on temperature preference were observed 1 hr after injection in mice aged 3, 5 and 7 days and at doses of 0.16, 0.48 and 1.6 mg/kg body weight. Although all 3 doses produced significant decreases in preferred temperature at 3 days, only the highest dose had significant effects at ages 5 and 7 days. Analysis of the data suggests that the dose-response relationship depends on age in a way that would be consistent with a shift in the dose-response curve with increasing age.

Pirenperone effects on temperature preference and body temperature in maturing mice.

Thermoregulatory effects of the selective 5-HT2 antagonist pirenperone were studied 1 hr after IP injection in mice aged 1, 3, 5, 7 and 10 days postpartum. Compared with vehicle injected littermates, a dose of 0.16 mg/kg decreased temperature preference (T pref) on a thermal gradient at all ages. No significant effects were observed on body temperature (Tb) at any of the ages. An increased dose (0.48 mg/kg) caused no greater effect on T pref and no significant effect on Tb. These results indicate that Tb and T pref are separable on the basis of receptor pharmacology, and are discussed in relation to drug effects on 5-HT2 receptors.

The maturational onset of the 5-HT mediated head twitch in mice.

The effect of elevated brain serotonin (5-hydroxytryptamine, 5-HT) on the head twitch was examined to determine an age of onset in mice for this 5-HT mediated motor activity. Two different treatments were used to elevate 5-HT: 100 mg/kg L-tryptophan with 100 mg/kg pargyline; and 100 mg/kg 5-HTP with 25 mg/kg carbidopa. Mice from ages 14 to 42 days postpartum were examined. Both treatments showed an onset of the head twitch at 15 days. Juvenile mice of 15-18 days appeared to differ in their response to the two treatments. Although 5-HTP and carbidopa stimulated head twitches, 5-HTP alone had a greater stimulatory effect at these ages, while in the other experiment only those animals receiving the combined tryptophan and pargyline treatment showed significant responses.

Biochemical and functional effects of fenfluramine in maturing mice.

Biochemical and functional effects of a single dose of fenfluramine were studied in maturing mice aged 1 day or 1, 2 or 6 weeks postpartum. 5-HT and 5-HIAA stores in hemispheres and brain stem were significantly reduced at all ages 1 day after the drug injection. In contrast to adult animals which showed continuing reductions in 5-HT and 5-HIAA 4 weeks after the fenfluramine injection, animals at all younger ages returned to normal by 1 week after the injection. Body weight was reduced 2-4 weeks after fenfluramine injection in 1 week old animals; however 2 week animals showed only a small transient reduction during the first week following fenfluramine. No significant effects were found on body temperature or temperature preference. The results are discussed in relation to the effects of various amine depleting agents.

A differential sex effect of amphetamine on exploratory behavior in maturing mice.

The effects of amphetamine (5-20 mg/kg) were studied 60 min after injection in mice aged 2, 3, 4 and 6 weeks postpartum. Exploratory behavior as indicated by the "head poke" test was depressed at all ages, but appeared to be relatively uncomplicated by other effects at the 5 mg/kg dose. At 4 and 6 weeks control females showed significantly greater activity than males, and amphetamine produced a greater reduction for control levels than in males.

Spatial development across the life span.

Fifth graders, ninth graders, college students, and persons over age sixty-five were given three pencil-and-paper tasks in spatial development. Knowledge of Euclidean space was assessed in each of these three tasks. In Task 1, the participants were asked to draw water lines in tilted bottles on a horizontal stand. In Task 2, they were asked to draw water lines in tilted bottles on a tilted stand. In Task 3, they were asked to give directions from one place to another on a hypothetical map. The performance on Task 1 and 2 increased from fifth grade to college. The performance of the elderly was the same as the college students on Task 1, and less than the college students in Task 2. The elderly participants' performance on Task 3 was better than the other three age groups. These results were discussed in terms of ecological validity, experience, and the number of competing cues to be processed simultaneously. Piaget's formulation on adult cognitive development was used to explain the elderly's performance in relation to other groups [1].

Thermoregulatory effects of the specific uptake inhibitor citalopram in maturing mice.

The effects of a single 20 mg/kg dose of citalopram (Lu 10-171) were studied in mice aged 1-10 days. Body temperature measured 2 and 24 hr after treatment was decreased in treated animals as compared with saline injected littermate controls. Two hours after treatment, temperature preference in a thermal gradient was unchanged in animals younger than 6 days; however, in animals 6 days or older, temperature preference was increased as compared with littermate controls. Twenty-four hours after treatment, temperature preference was increased in citalopram-treated animals at all ages tested. The results are discussed in relation to nervous system maturation.

Effect of lithium on reproduction and postnatal growth of mice.

Mating pairs of mice were maintained continuously on drinking water containing 50 mEq/l LiCl and its effects on reproduction and postnatal development were monitored. In mating pairs put on lithium at 6-8 weeks of age, the lithium does not appear to reduce litter size at birth but it does increase postnatal mortality and the length of time between litters, and reduces the total number of litters a mating pair may have. In mating pairs put on lithium at 3 weeks of age, it severely delays postnatal growth and development of all pups in the litter. With the exception of the liver, this delayed growth and development does not appear to affect internal organs as severely as somatic body parts. This delayed growth may be the result of some effect lithium may have on certain hormones such as prolactin, thyroxine and growth hormone.

Reserpine effects on body temperature in maturing mice.

1. The effects of a single dose of reserpine (1 mg/kg body wt) have been studied 1 hr and 24 hr after injection. Young mice were tested on days 3, 7, 10 and 14 after birth and compared with 6-week-old adults. 2. Body temperature (Tb) fell in reserpine-treated young animals 1 hr after injection, as compared with vehicle-treated littermate controls; however, the effect was small in 3- and 7-day animals when compared with 10- and 14-days. 3. Tb was significantly depressed in young reserpine-treated animals 24 hr after injection, with greater effects again found in the 10- and 14-day animals. In contrast, the adult animals failed to show an effect on Tb at either 1 hr or 24 hr after injection. 4. A second dose of reserpine 24 hr after the first dose was ineffective in producing further changes in Tb in 3-, 7-, and 10-day animals; but in 14-day and adult animals the second dose produced a significant decrease in Tb.

The effects of the specific uptake inhibitor Lu 10-171 (citalopram) upon brain indoleamine stores in the maturing mouse.

1. The specific 5-HT uptake inhibitor Lu 10-171 (Citalopram) was used to test uptake inhibition and reduced turnover in maturing mouse brain. 2. All ages showed 5-hydroxyindole acetic acid (5-HIAA) elevation indicative of inhibition and reduced turnover. Enzymatic blockade in conjunction with Lu 10-171 supported the evidence for reduced turnover. 3. The significance of early serotonergic maturation is discussed.