A Upf3b-mutant mouse model with behavioral and neurogenesis defects

Nonsense-mediated RNA decay (NMD) is a highly conserved and selective RNA degradation pathway that acts on RNAs terminating their reading frames in specific contexts. NMD is regulated in a tissue-specific and developmentally controlled manner, raising the possibility that it influences developmental events. Indeed, loss or depletion of NMD factors have been shown to disrupt developmental events in organisms spanning the phylogenetic scale. In humans, mutations in the NMD factor gene, UPF3B, cause intellectual disability (ID) and are strongly associated with autism spectrum disorder (ASD), attention deficit hyperactivity disorder (ADHD) and schizophrenia (SCZ). Here, we report the generation and characterization of mice harboring a null Upf3b allele. These Upf3b-null mice exhibit deficits in fear-conditioned learning, but not spatial learning. Upf3b-null mice also have a profound defect in prepulse inhibition (PPI), a measure of sensorimotor gating commonly deficient in individuals with SCZ and other brain disorders. Consistent with both their PPI and learning defects, cortical pyramidal neurons from Upf3b-null mice display deficient dendritic spine maturation in vivo. In addition, neural stem cells from Upf3b-null mice have impaired ability to undergo differentiation and require prolonged culture to give rise to functional neurons with electrical activity. RNA sequencing (RNAseq) analysis of the frontal cortex identified UPF3B-regulated RNAs, including direct NMD target transcripts encoding proteins with known functions in neural differentiation, maturation and disease. We suggest Upf3b-null mice serve as a novel model system to decipher cellular and molecular defects underlying ID and neurodevelopmental disorders.

Atmospherically relevant core–shell aerosol studied using optical trapping and Mie scattering

Solid core–liquid shell aerosols have been trapped in a counter-propagating optical trap confirming potential core–shell morphology in the atmosphere.

Characterization of Escherichia coli populations from gulls, landfill trash, and wastewater using ribotyping

Due to their opportunistic and gregarious nature, gulls may be important reservoirs and vectors for anthropogenically derived fecal pathogens in coastal areas. We used ribotyping, a genotypic bacterial source tracking method, to compare populations of Escherichia coli among herring gulls Larus argentatus, great black-backed gulls L. marinus, wastewater, and landfill trash in New Hampshire and Maine, USA. Concentrations of E. coli in gull feces varied widely among individuals, but were generally high (6.0 x 10(1) to 2.5 x 10(9) g(-1) wet weight). Of 39 E. coli isolates from L. argentatus, 67% had banding patterns that were > or = 90% similar to those from wastewater and trash, whereas only 39% of 36 L. marinus isolates exhibited > or = 90% similarity to these sources. Strains of E. coli from gulls matched (> or = 90% similarity) more strains from wastewater (39% matching) than from trash (15% matching). E. coli isolates from L. marinus feces exhibited a greater diversity of banding patterns than did isolates from L. argentatus. There were more unique E. coli banding patterns in trash samples than in wastewater, and higher diversity indices in the former compared to the latter. These findings suggest that both species of gulls, especially L. argentatus, obtain fecal bacteria from wastewater and landfill trash, which they may transport to recreational beaches and waters. Our results also indicate that E. coli populations may vary widely between gull species, and between the anthropogenic habitats that they frequent, i.e. landfills and wastewater treatment facilities.

Circadian rhythms, multilevel models of emotion and bipolar disorder--an initial step towards integration?

This paper sets out possible links between disruption of circadian rhythms in bipolar disorder and the affective symptom, which are experienced in this disorder. Evidence is drawn from Healy and Williams' [Psychiatr. Dev. 1 (1989) 49.] review of circadian function in manic depression, along with later reports, which indicate a role for disrupted circadian rhythms in both depressed and manic phases of manic depression (bipolar disorder). This is integrated within a version of the multilevel model of emotion proposed by Power and Dalgleish [Cognition and emotion: from order to disorder. Hove: Psychology Press (1997); Behav. Cognit. Psychother. 27 (1999) 129.]. The aim of this process is to propose a possible psychological mechanism by which the disruption of circadian rhythms might result in the observed clinical symptoms of bipolar disorder. The integration of these approaches leads to a number of specific testable hypotheses that are relevant to future research into the psychological treatment and understanding of bipolar disorder.

Gulfwatch: monitoring spatial and temporal patterns of trace metal and organic contaminants in the Gulf of Maine (1991-1997) with the blue mussel, Mytilus edulis L

Gulfwatch, established in 1991, is an international contaminant monitoring program in which the blue mussel, Mytilus edulis, is used as an indicator of the level and extent of contamination in the Gulf of Maine. Since 1991, trace metals, PAHs, PCBs, and OC pesticides have been measured in mussel tissues at 56 sites. The distribution of most metals was relatively uniform throughout the Gulf with the exception of Ag, Pb and Cr. However, the concentration of organic contaminants increased in a north-to-south direction. High concentrations of contaminants were correlated with large human population density and proximity to large rivers. Temporal analysis of five sites revealed that the majority of contaminant concentrations were either unchanged or decreasing. The concentrations of most contaminants were lower than the median of the National Status and Trends (NS & T) Mussel Watch with the exceptions of Cr, Hg, Pb and sigma PCB24. Hg concentrations at > 80% of the Gulfwatch sites exceeded the NS & T median +1 SD. Gulfwatch continues as a primary contaminant monitoring program in the Gulf of Maine.

Impaired associative learning in chronic schizophrenics and their first-degree relatives: a study of latent inhibition and the Kamin blocking effect

The performance of chronic schizophrenic probands (n=21), their first-degree schizotypal (22) and non-schizotypal (19) relatives, and normal controls (24), was measured in two associative learning paradigms, latent inhibition and the Kamin blocking effect. These paradigms assess the effects on learning of initial exposure to other learning contingencies. The normal subjects showed latent inhibition (retarded learning of an association between a burst of white noise and a visually displayed counter increment, if the subject had first been pre-exposed to the white noise without any other consequence) and Kamin blocking (retarded learning of an association between two visual stimuli, if the conditioned stimulus was presented simultaneously with a second, already conditioned stimulus). The schizophrenic probands and both the schizotypal and non-schizotypal relatives were severely impaired in basic associative learning, performing much worse than the normal subjects in the control conditions (i.e. those lacking stimulus pre-exposure of any kind) of both the latent inhibition and the Kamin paradigms and also showed a loss of the normal latent inhibition and Kamin blocking effects. The performance of the three clinically defined groups was statistically indistinguishable. These findings contrast with previous reports of the performance of normal subjects classified as schizotypal by questionnaire, who are not impaired in basic associative learning, and are particularly fast to learn after stimulus pre-exposure. The results question the assumption that high schizotypy, as assessed by questionnaire, is like schizotypy in schizophrenic kin. The severe impairment in basic associative learning in schizophrenic patients and their kin warrants further investigation.

A program design to promote clinical judgment

This article describes a unique continuing education program designed to enhance critical thinking, clinical judgment, and communication skills of practicing nurses in an acute care setting. The program design and implementation strategies are described in detail. The authors include specific examples for those who want to develop a similar program to improve the practice of registered nurses in the acute care setting.

Interesting times on Krakatau: stand dynamics in the 1990s

The Krakatau Islands, Indonesia, have provided an opportunity for ecologists to track primary succession from the 'clean slate' of 1883, through forest closure in the 1920s, to the contemporary period, in which successional changes take the form of alterations in composition and stature of forest stands rather than gross changes in ecosystem type. This paper reports on permanent forest plots established on the islands in 1989, and fully surveyed again in both 1992 and 1997. Since 1989, the plots have been subject to natural disturbance phenomena in the form of varying combinations of, for example, deposition of volcanic ejecta, landslides, lightning strikes, storm damage and drought. These effects have been concentrated between 1992 and 1997, during which the volcano Anak Krakatau has deposited ash on the islands of Sertung and Panjang, but not on Rakata. Data on stand responses are presented for growth rates (dbh (diameter at breast height, 1.3 m) increment), stem recruitment and mortality, biomass changes partitioned into mortality, ingrowth and growth of established trees), and compositional shifts. The discussion focuses on evaluation of questions and successional models framed earlier in the programme. One general finding is that the stand dominants as of 1989 have tended to decline in number within the plots, generally through low levels of recruitment failing to balance rates of mortality. The effects of disturbance to the plots appear to be evident in terms of mortality and recruitment, dbh increment, and changes in biomass. The patterns of change in the eight plots are quite varied, such that relatively few generalizations are possible. The difficulties of establishing meaningful baseline rates for tree growth and stand biomass are discussed.

Is Bradburn's measure of psychological well-being fair to introverts? A study among 16- to 18-yr.-old students

A sample of 242 students between the ages of 16 and 18 years, attending schools in the North East of England, completed the Bradburn Balanced Affect Scale together with the abbreviated form of the Revised Eysenck Personality Questionnaire. The findings show that scores on the Bradburn scale (indicating psychological well-being as assessed by balanced affect) are correlated significantly and positively with scores for Extraversion (.25), negatively with Neuroticism (.52) and nonsignificantly with Psychoticism. The implications of these findings are discussed for the assessment of psychological well-being among introverts.

Kamin blocking is not disrupted by amphetamine in human subjects

The effect of oral amphetamine administration on the Kamin-blocking effect in healthy volunteer subjects was investigated. Against predictions, Kamin blocking was not disrupted by either a high or low oral dose of D-amphetamine under conditions which have, in previous studies, led to disruption of a related learning phenomenon (latent inhibition). This lack of effect of amphetamine administration upon Kamin blocking weakens hypotheses that this cognitive process is mediated by the same changes in dopaminergic activity which affect latent inhibition. Currently, the only data which show strong comparative associations between Kamin blocking and latent inhibition are when they are applied to schizophrenic populations. These results may suggest that Kamin blocking and latent inhibition may be measuring different aspects of schizophrenic cognitive dysfunction.

Cognitive functioning and GABAA/benzodiazepine receptor binding in schizophrenia: a 123I-iomazenil SPET study

BACKGROUND

The role of the inhibitory neurotransmitter gamma aminobutyric acid (GABA) in schizophrenia has previously been investigated using postmortem material. Recently, using single photon emission tomography (SPET) with the selective benzodiazepine antagonist 123I-Iomazenil as the radioligand, we have demonstrated an in vivo relationship between reduced GABAA/benzodiazepine receptor binding and the severity of positive symptomatology in schizophrenia. The present study aimed to build on this using the same in vivo scanning techniques, and relating findings to cognitive functioning.

METHODS

Ten nonpsychiatric control subjects and 15 schizophrenic patients, matched for age and handedness, were scanned. A battery of neuropsychologic tests was also administered.

RESULTS

Correlational analysis revealed a pattern of increased correlations between GABAA/benzodiazepine receptor binding and task performance, in the schizophrenic group compared to the control group.

CONCLUSIONS

Findings are preliminary but suggest a relationship between reduced GABAA/benzodiazepine receptor binding and poorer cognitive functioning, involving memory and visual attention processes, in the schizophrenic group but not in the control group. A role for GABA in the pathophysiology of schizophrenia is suggested. Limitations of the present study and suggestions for future research are discussed.

Babesia bovis: genome size, number of chromosomes and telomeric probe hybridisation

Pulsed field gel electrophoresis of intact chromosomes of Babesia bovis revealed four chromosomes in the haploid genome. A telomere probe, derived from Plasmodium berghei, hybridised to eight SfiI restriction fragments of genomic B. bovis DNA digests indicating the presence of four chromosomes. A small subunit (18S) ribosomal RNA gene probe hybridised to the third chromosome only. The genome size of B. bovis is estimated to be 9.4 million base pairs. The sizes of chromosomes 1, 2, 3 and 4 are estimated to be 1.4, 2.0, 2.8 and 3.2 million base pairs, respectively.

Disruption of the Kamin blocking effect in schizophrenia and in normal subjects following amphetamine

The Kamin blocking effect (KBE) is an established animal learning paradigm measuring selective processing, in which reduced blocking reflects allocation of greater processing resources to non-relevant information. Two KBE tasks are described below. Results from studies using the first (between-subjects) task indicate that KBE is abolished in acute schizophrenics with positive psychotic symptoms. It is also abolished in the relatives of schizophrenic subjects, although interpretation of this finding is hampered by poor performance of subjects in the control condition. The second (within-subjects) task indicated abolition of KBE in schizophrenic patients with positive psychotic symptoms. Administration of acute amphetamine to normal human subjects did not significantly disrupt performance on the first task. Whilst for the second task, although blocking was limited to placebo subjects, overall pre-exposure effects are not sufficiently strong to indicate specific drug effects.

A brief mental health outcome scale: relationships between scale scores and diagnostic/sociodemographic variables in the long-term mentally ill

The Global Assessment of Functioning (GAF) scale is a quick and simple measure of overall psychological disturbance. A recent study by our group reported the reliability and validity of the scale in a population of severely mentally ill people. The current study extends the analysis of this population to consider a number of questions, i.e. what are the associations for this group between variations in GAF scores and sociodemographic variables? Are lower scores associated with particular diagnoses for the group assessed? What are the characteristics of those patients whose scores were most variable? What were the completion rates for use of the scale? No associations were observed between GAF score and the sociodemographic variables used in this study. Lower GAF scores were associated with psychotic diagnoses. Those with most varying scores were, in the main, white European non-immigrant males with a diagnosis of schizophrenia. Completion rates for the study were reasonable at 73.8%. This study involved the repeated assessment of a large number of clients by a changing multidisciplinary team. Inspite of the extended nature of the study, completion rates remained reasonable, suggesting that the scale was acceptable for routine clinical use. The GAF in itself, however, appears to be unsuitable for making individual treatment decision but could be used as a first step before using more sophisticated scales.

A brief mental health outcome scale-reliability and validity of the Global Assessment of Functioning (GAF)

BACKGROUND

The Global Assessment of Functioning (GAF) is a quick and simple measure of overall psychological disturbance. However, there is little research on the reliability and validity of this measure in severely mentally ill populations.

METHOD

Multidisciplinary keyworkers assessed 103 patients at monthly intervals over a 6-month period. Overall GAF scores were obtained, with additional separate ratings for symptoms and disability. These were compared with changes in antipsychotic medication and support needs over the same period.

RESULTS

Satisfactory reliability was obtained for total GAF score and for symptom and disability measures, in spite of raters having only one brief training session. All GAF scores were associated with current support needs of patients. Symptom and disability scores were associated with changes in antipsychotic medication in the previous month. Only symptom score was associated with increases in antipsychotic medication at time of rating.

CONCLUSION

GAF proved to be a reliable and, within the limits of the indicators used, a valid measure of psychiatric disturbance in our sample of the severely mentally ill. Differences in relationships between the three GAF scores and medication/support needs indicate the usefulness of obtaining all three scores for monitoring levels and type of psychiatric disturbance in this population.

Analysis of the functional potential of mouse CD4+ T cells using a high-efficiency cloning system

In order to examine the functional potential of individual mouse CD4+ T cells selected, as far as possible, in a random manner, a high-efficiency cloning system driven by Con A was utilized. Under optimal conditions, cloning efficiencies of CD4+ cells of about 50% were regularly attained. Although the relative proportion of different TH subsets varied depending on the cloning conditions, the high cloning efficiency, coupled with the analysis of over 100 clones, allowed important conclusions to be drawn regarding the general construction of the mouse CD4+ T cell repertoire. (1) At least 50% of all mouse splenic CD4+ T cells have the potential to produce IL4, supporting the view that TH subsets arise by an instructional or regulatory mechanism, rather than by selection. (2) TH0 clones produce amounts of IL2 and IL4 similar to those produced by TH1 and TH2 clones, respectively, but secrete much lower quantities of IFN than TH1 clones. (3) A large proportion of TH2 clones secrete measurable amounts of IFN. (4) Lymphokine secretion patterns among CD4+ T cells are clearly not determined at random, since IL2 production is always accompanied by IFN production. (5) At least 50% of all mouse splenic CD4+ T cells have cytolytic capacity as shown by killing in a 20-hr assay, but only a proportion can also kill in 4-hr assays. Killing in 4-hr assays was strongly correlated with the ability to secrete IL2, regardless of whether IL4 was also secreted.

Loss of the Kamin blocking effect in acute but not chronic schizophrenics

Differences between research diagnostic criteria (RDC)-diagnosed acute and chronic schizophrenics and normal controls were studied using a Kamin blocking procedure. Blocking is an established animal learning procedure, thought by some researchers to reflect selective attention; decreased blocking indicates increased processing of irrelevant stimuli. It was predicted that this pattern would be obtained in acute schizophrenics, tested soon after admission, for two reasons: (1) evidence from previous clinical studies indicates that acute schizophrenics are more aware of nonsalient aspects of their environment than controls; and (2) blocking is disrupted in animals in a hyperdopaminergic state and restored by neuroleptic medication. This was the case: acute, but not chronic, schizophrenics showed disrupted blocking. This disruption was especially clear in those acute schizophrenics tested within 2 weeks of hospital admission. By the second test session (in a cross-over design), there was some evidence of normalization in performance in the acute schizophrenics. These findings are considered with regard to the dopamine hypothesis of schizophrenia.

Improving retention and graduation rates for black students in nursing education: a developmental model

High attrition rates among black students are a significant factor in the decline in graduation rates from nursing programs. Nursing education needs a program to address problems of anger, frustration, and loneliness and to develop the black student as a whole person.

Components of supervisors' ratings of therapists' skillfulness

A questionnaire was developed to assess the skillfulness of therapists from the perspective of the supervisor. This supervisor report yielded two scores: one for psychotherapeutic techniques and one for the educational alliance. These scores had high internal consistency and were relatively independent of one another. Ratings of proficiency in psychotherapeutic techniques accounted for 54% of the variance in supervisors' rating? of global skillfulness; educational alliance contributed an additional 12%. Compared with other supervisors, those who espoused self psychology based more of their appraisal of skill fulness on the trainee's use of the supervisory relationship.

Contextual effects on choice reaction time and accuracy in acute and chronic schizophrenics. Impairment in selective attention or in the influence of prior learning?

Two hypotheses were tested concerning the nature of the cognitive dysfunction in schizophrenia: (a) that there is a broadening of selective attention; and (b) that there is an impairment in associational learning. RDC-diagnosed acute and chronic schizophrenics and normal controls carried out a choice reaction time (RT) task in which conflict between the correct response to a target (a letter in the centre of a computer screen) and that cued by simultaneously presented flankers (two letters either side of the target) increased RT. For 80 ('valid') trials, flankers and targets were consistent in the response cued (pressing a button with either left or right hand); on 8 ('invalid') trials they conflicted. On invalid trials there was a slowing of RT, and an increase of errors for left-hand responses. Chronic schizophrenics showed the same reactions to cue validity as normal controls, both groups differing significantly from acute schizophrenics. For the latter, the RT data supported hypothesis (b), but the error rates appeared to support hypothesis (a).

Incidence of Vibrio vulnificus in northern New England water and shellfish

Vibrio vulnificus, an autochthonous inhabitant of the estuarine environment, was detected in water and oysters from the Great Bay Estuary System of New Hampshire and Maine. Previously, it had not been detected north of Boston Harbor on the east coast of the United States. V. vulnificus was detected in water and shellfish samples at five out of ten sites, and only in areas that were not open to recreational shellfishing. Although samples were collected from May into December, V. vulnificus was only detected in shellfish in July and August. Water sampling began in August, and V. vulnificus persisted at one site into October.

Mechanism of phenylalanine regulation of phenylalanine hydroxylase

The mechanism of phenylalanine regulation of rat liver phenylalanine hydroxylase was studied. We show that phenylalanine "activates" phenylalanine hydroxylase, converting it from an inactive to active form, by binding at a true allosteric regulatory site. One phenylalanine molecule binds per enzyme subunit; it remains at this site during catalytic turnover and, while there, cannot be hydroxylated. Loss of phenylalanine from the site causes a loss of enzymatic activity. The rate of loss of activation is dramatically slowed by phenylalanine, which kinetically "traps" activated enzyme during relaxation from the activated to unactivated state. An empirical equation is presented which allows calculation of relaxation rates over a wide range of temperatures and phenylalanine concentrations. Kinetic trapping by phenylalanine is a novel effect. It was analyzed in detail, and its magnitude implied that phenylalanine activation involves cooperativity among all four subunits of the enzyme tetramer. A regulatory model is presented, accounting for the properties of the phenylalanine activation reaction in the forward and reverse directions and at equilibrium. Fluorescence quenching studies confirmed that activation increases the solvent accessibility of the enzyme's tryptophan residues. Physical and kinetic properties of purified phenylalanine hydroxylase from rat, rabbit, baboon, and goose liver were compared. All enzymes were remarkably alike in catalytic and regulatory properties, suggesting that control of this enzyme is similar in mammals and birds.

Fifth disease: role for nurses in pediatric practice

Parvovirus B19 infection is a common childhood disease. Infection is usually mild but may have serious consequences in pregnant women. Nurses in pediatric practice may be the only health professionals in a position to recognize and intervene in this potentially serious condition in certain high risk individuals.

The Kamin blocking effect, incidental learning and psychoticism

The Kamin blocking effect consists in impaired learning of an association between a conditioned stimulus (CS2) and an unconditioned stimulus (UCS) if CS2 is presented simultaneously with a different CS (CS1) already associated with the UCS. It is well established with animal but not human subjects. In the two experiments presented here, the effect was clearly demonstrated with UCS = a computer-presented yellow square, CS1 = a blue square and CS2 = a noise (Expt 1) or two smaller white squares (Expt 2). The Kamin effect has, by some theorists, been attributed to switching of attention away from CS2, which conveys only redundant information. If so, the size of the effect should co-vary with indices of selective attention commonly used with human subjects. As predicted, the blocking effect was found to be smaller in subjects who displayed a high degree of incidental learning in either of two tasks in which intentional vs. incidental learning corresponded to (1) words vs. word position, or (2) a target initial word letter vs. non-target initial letters. We report elsewhere that the blocking effect is absent in acute schizophrenics. In the present experiments, however, there was no systematic relation between any of four measures of psychoticism, or intelligence, and either the blocking effect or incidental learning.

Effect of inorganic nutrients on the acclimation period preceding mineralization of organic chemicals in lake water

The addition of phosphate, nitrate, or sulfate (each at 10 mM) decreased the acclimation period for the mineralization of low concentrations of p-nitrophenol (PNP) in lake water. Added phosphate shortened the acclimation period for biodegradation of 2 ng to 2 micrograms of PNP per ml in various lake water samples and of 2,4-dichlorophenoxyacetate at 100 ng/ml. Added P enhanced the rate of growth of PNP-mineralizing microorganisms in waters containing 200 ng or 2 micrograms of PNP per ml. We suggest that the effect of P on the acclimation period results from an increase in the growth rate of the initially small population of microorganisms able to mineralize the synthetic chemicals.

Explanations for the acclimation period preceding the mineralization of organic chemicals in aquatic environments

A study was conducted of possible reasons for acclimation of microbial communities to the mineralization of organic compounds in lake water and sewage. The acclimation period for the mineralization of 2 ng of p-nitrophenol (PNP) or 2,4-dichlorophenoxyacetic acid per ml of sewage was eliminated when the sewage was incubated for 9 or 16 days, respectively, with no added substrate. The acclimation period for the mineralization of 2 ng but not 200 ng or 2 micrograms of PNP per ml was eliminated when the compound was added to lake water that had been first incubated in the laboratory. Mineralization of PNP by Flavobacterium sp. was detected within 7 h at concentrations of 20 ng/ml to 2 micrograms/ml but only after 25 h at 2 ng/ml. PNP-utilizing organisms began to multiply logarithmically after 1 day in lake water amended with 2 micrograms of PNP per ml, but substrate disappearance was only detected at 8 days, at which time the numbers were approaching 10(5) cells per ml. The addition of inorganic nutrients reduced the length of the acclimation period from 6 to 3 days in sewage and from 6 days to 1 day in lake water. The prior degradation of natural organic materials in the sewage and lake water had no effect on the acclimation period for the mineralization of PNP, and naturally occurring inhibitors that might delay the mineralization were not present. The length of the acclimation phase for the mineralization of 2 ng of PNP per ml was shortened when the protozoa in sewage were suppressed by eucaryotic inhibitors, but it was unaffected or increased if the inhibitors were added to lake water.(ABSTRACT TRUNCATED AT 250 WORDS)

A graphical presentation of three-dimensional joint mobility

Reduction of joint mobility in humans is a very common medical condition which results from trauma or joint disease. However, there is currently no satisfactory way of plotting the three-dimensional rotations which completely define this mobility. The most usual method of presenting the results from the many systems for measuring joint mobility is to plot graphs of the three angles of rotation, individually, against time, or to plot two angles of rotation against one another. However, this latter excludes the third angle of rotation which has to be presented separately. This paper suggests a technique known as the hemispherical projection method for the plotting of three-dimensional joint mobility data. The technique is derived from the fields of structural geology and rock mechanics where it is used for presenting and analysing orientation information on discontinuity planes in rock. Data from human hip and spine movements have now been successfully plotted using a microcomputer. This will provide an opportunity for straightforward comparison of movements between individuals and patient groups using the shape of the output graphs as a clinical aid. In addition, it is suggested that 'indices of mobility' may be derived from the plots. These indices could be used to quantify joint disability using the area enclosed by, and the asymmetry of, the plot.

Kinetics of mineralization of phenols in lake water

The kinetics of mineralization of phenol and p-nitrophenol in lake water was determined at concentrations from 200 pg/ml to 5 micrograms/ml. The mineralization data were fit by nonlinear regression to equations for 14 kinetic models that describe patterns of biodegradation by nongrowing cells or by microorganisms growing on either the test chemical or other organic substrates. The kinetics od mineralization of phenol in water samples collected in July was best described by first-order models for 0.5 ng of phenol per ml; by Monod-without-growth, logistic, and logarithmic models for 1.0 and 2.0 ng/ml and 5.0 ng/ml to 1.0 micrograms/ml, respectively, if it is assumed that the mineralizing population uses phenol as the sole carbon source for growth; by models (for phenol at concentrations of 2.0 ng/ml to 1.0 micrograms/ml) that assume that the phenol-mineralizing populations do not grow or grow logarithmically or logistically on uncharacterized carbon compounds but metabolize the phenol when present at levels below and above Km, respectively, for that compound; and by a logarithmic model at 5.0 micrograms/ml. Under the test conditions, usually less than 10% of the phenol C that was metabolized was incorporated into microbial cells or retained by other particulate material in the water at substrate concentrations of 10 ng/ml or less, and the percentage increased at higher substrate concentrations.(ABSTRACT TRUNCATED AT 250 WORDS)

Anomalies in mineralization of low concentrations of organic compounds in lake water and sewage

The rates of mineralization of nitrilotriacetic acid (NTA), 2,4-dichlorophenoxyacetic acid (2,4-D), p-nitrophenol, aniline, and isopropyl N-phenylcarbamate (IPC) at one or more concentrations ranging from 100 pg/ml to 1.0 microgram/ml were proportional to chemical concentrations in samples of three lakes. The rates at 100 pg of NTA, 2,4-D, p-nitrophenol, and aniline per ml in samples of one or more lakes were less than predicted, assuming the rates were linearly related to the concentration. Neither NTA nor 2,4-dichlorophenol at 2.0 ng/ml was mineralized in some lake waters, but higher levels of the two chemicals were converted to CO2 in samples of the same waters. In samples from two lakes, little or no mineralization of IPC or 2,4-D occurred at 1.0 microgram/ml, but 10 ng/ml or lower levels of the herbicides were mineralized. The mineralization in sewage of 1.0 microgram of NTA per ml was biphasic; about 20% of the substrate was mineralized in 20 h, and mineralization was only reinitiated after a period of 130 h. The biphasic transformation was not a result of the accumulation of organic products, and it was still evident if protozoan activity was inhibited. NTA also underwent a biphasic mineralization in lake waters, and the biphasic pattern was not altered by additions of growth factors and inorganic nutrients. From 40 to 60% of the carbon of aniline added to lake water at levels of 100 pg/ml to 1.0 microgram/ml was mineralized, but more than 90% of the carbon of NTA, 2,4-D, or p-nitrophenol added to lake water at 10 ng/ml or 1.0 microgram/ml was mineralized.(ABSTRACT TRUNCATED AT 250 WORDS)

Reactions of trifluoromethyl and methyl radicals with ethylene oxide

The reaction between CF3 radicals and ethylene oxide was studied in the range 60–228 °C using CF3I as a radical source. For the reactions,[Formula: see text]we obtain[Formula: see text]where θ = 2.3 RT kcal mole−1Published data of Phibbs and Darwent on the reaction[Formula: see text]have been re-calculated and it is suggested that both the original and re-calculated values of the activation energy E5 are too low. The Arrhenius parameters for the reactions of CF3 and CH3 radicals with ethylene oxide are compared with those for related reactions.