Pediatric emergency department physicians' perceptions of virtual mental health assessments for urgent needs.

PURPOSE: Pressures related to the COVID-19 pandemic have created the need to develop innovative ways to deliver mental health care, especially for urgent needs. After the launch of a pediatric Emergency Department (ED) Virtual Care service, we aimed to evaluate pediatric ED physicians' experiences with the use of ED virtual care for mental health assessments. METHODS: This mixed-methods study was conducted at a pediatric academic health center in Ontario, Canada. Pediatric ED physicians who conducted ED virtual mental health assessments from May to December 2020 were eligible. Participants completed a 22-question novel survey and were invited to participate in a focus group. Descriptive and thematic analyses were used to analyze the data. RESULTS: Twenty-nine physicians provided mental health services through the ED virtual care platform. Twenty-five physicians (86% response rate) completed the survey and 3 (10%) participated in a focus group. While many agreed that virtual care benefits patients (67%), key barriers identified included time constraints, lack of mental health clinician support, and uncertainty around the pediatric ED physicians' role in these types of assessments. Despite these barriers, physicians recognized the potential benefit of the ED virtual care service for mental health assessments and were largely amenable to improving this process should mental health support be available. CONCLUSIONS: While many physicians agreed that there is a potential benefit of the ED virtual care platform for urgent mental health assessments, time constraints and lack of confidence in providing satisfactory virtual mental health care with minimal mental health support limited its acceptability. These findings can inform the future implementation of mental health services using an innovative virtual ED platform.

RéSUMé: OBJECTIF: Les pressions liées à la pandémie de COVID-19 ont créé le besoin de développer des moyens innovants pour fournir des soins de santé mentale, en particulier pour les besoins urgents. Après le lancement d'un service de soins virtuels aux urgences pédiatriques, nous avons cherché à évaluer les expériences des médecins des urgences pédiatriques avec l'utilisation des soins virtuels aux urgences pour les évaluations de la santé mentale. MéTHODOLOGIE: Cette étude à méthodes mixtes a été menée dans un centre universitaire de santé pédiatrique en Ontario, au Canada. Les médecins pédiatriques qui ont effectué des évaluations virtuelles de la santé mentale aux urgences de mai à décembre 2020 étaient admissibles. Les participants ont rempli une enquête inédite de 22 questions et ont été invités à participer à un groupe de discussion. Des analyses descriptives et thématiques ont été utilisées pour analyser les données. RéSULTATS: Vingt-neuf médecins ont fourni des services de santé mentale par le biais de la plateforme de soins virtuels des urgences. Vingt-cinq médecins (taux de réponse de 86 %) ont répondu au sondage et trois (10 %) ont participé à un groupe de discussion. Si beaucoup s'accordent à dire que les soins virtuels sont bénéfiques pour les patients (67 %), les principaux obstacles identifiés sont les contraintes de temps, le manque de soutien des cliniciens en santé mentale et l'incertitude quant au rôle des urgentistes pédiatriques dans ces types d'évaluations. Malgré ces obstacles, les médecins ont reconnu l'avantage potentiel du service de soins virtuels de l'urgence pour les évaluations de la santé mentale et étaient largement disposés à améliorer ce processus si un soutien en santé mentale était disponible. CONCLUSIONS: Bien que de nombreux médecins s'accordent à dire que la plateforme de soins virtuels des urgences présente un avantage potentiel pour les évaluations urgentes de la santé mentale, les contraintes de temps et le manque de confiance dans la prestation de soins de santé mentale virtuels satisfaisants avec un soutien minimal en matière de santé mentale ont limité son acceptabilité. Ces résultats peuvent éclairer la mise en œuvre future des services de santé mentale à l'aide d'une plateforme virtuelle d'urgence innovante.

Low energy (1-19 eV) electron scattering from condensed thymidine (dT) I: absolute vibrational excitation cross sections.

Absolute cross sections (CSs) for vibrational excitation by electrons of energy between 1-19 eV scattering from condensed thymidine (dT) were measured by means of high-resolution electron energy loss spectroscopy (HREELS). The CSs were extracted from electron energy loss spectra of dT condensed on multilayers film of Ar held at about 20 K under ultra-high vacuum (∼1 × 10-11 Torr). dT is one of the most complex molecules to be studied in condensed phase by HREELS. The magnitudes of the vibrational CSs lie within the 10-17 cm2 range. Structures observed in the energy dependence of the vibrational CSs under 3 eV and around 4 eV were compared with previous results of gas- and solid-phase studies on dT and related molecules (e.g., thymine and tetrahydrofuran). These structures were attributed to the formation of shape resonances.

Low energy (1-19 eV) electron scattering from condensed thymidine (dT) II: comparison of vibrational excitation cross sections with those of tetrahydrofuran and the recalibrated values of thymine.

Recent measurements of absolute vibrational cross sections (CSs) for low-energy electron (LEE) scattering from condensed thymidine (dT) allows comparison with CSs of its constituents; thymine and tetrahydrofuran (THF). To facilitate this comparison, the vibrational CSs of condensed thymine were remeasured at six electron incident energies and a correction was applied to the earlier thymine CS values measured by Lévesque et al. [Nucl. Instrum. Methods Phys. Res., Sect. B, 2003, 208, 225]. The incident energy dependence of the CS of each vibrational mode of dT is compared with the corresponding modes in thymine and/or THF. It is found that the magnitude of the CSs of the thymine breathing mode and the C-C stretch mode of THF are greatly attenuated in dT. Finally, the magnitudes of the total vibrational CSs of each molecule are compared. Below 4 eV, the total vibrational CSs of dT is greater than each of its two constituents. Interestingly, at higher energy (>6 eV), the magnitude of the total vibrational CS of dT is roughly equal to that of THF and is greater than thymine by only 15% at 10 eV, showing that the CSs of dT cannot be approximated by the addition of the CSs of its constituents over the entire energy range. These comparisons are discussed in terms of the basic principles involved in the formation and decay of shape resonances, which are known to be responsible for major enhancements of LEE-induced vibrational excitation at low electron energies.

Absolute cross section for DNA damage induced by low-energy (10 eV) electrons: Experimental refinements and sample characterization by AFM.

This work describes multiple experimental improvements for measuring absolute cross sections of DNA damage induced by low-energy electrons in nanometer-thick films in vacuum. Measurements of such cross sections are particularly sensitive to film thickness and uniformity. Using atomic force microscopy in 70% ethanol, we present a novel and effective method to determine plasmid DNA film thickness and uniformity that combines height histograms and force-distance curves. We also investigate film deposition with DNA intercalated with 1,3-diaminopropane (Dap) on tantalum-coated substrates as a convenient and cost-effective alternative to the previously-used graphite substrate. The tantalum substrate permits deposition of films very similar to those formed on graphite. Using these refinements and further optimizations of the experimental procedure, we measure an absolute cross section of (7.4 ± 2.3) × 10-18 cm2 per nucleotide for conformational damage to a 3197 base-pair plasmid, induced by 10 eV electrons, which we believe should be considered as a reference value.

Electron stimulated desorption from condensed pyrimidine and pyridazine.

Low energy electron (LEE) interactions and the formation of transient negative ions play a dominant role in radiation-induced dissociation of condensed-phase biomolecules (e.g. in radiotherapy). Here we present data on the LEE-induced dissociation and desorption of the DNA/RNA-base and radiosensitizing agent analogues pyrimidine and pyridazine. Vapors of each molecule were condensed on either a Pt or Ar substrate to form a multilayer film or a submonolayer molecular target, respectively. These were irradiated with electrons of 0-80 eV and the desorbing anionic and cationic fragments analysed via time of flight mass spectrometry. The detected cations are the same species seen in gas-phase mass spectra, albeit of differing relative intensity. Anion yield functions exhibit strong maxima, indicating that transient negative ions contribute significantly, via dissociative electron attachment (DEA), to molecular dissociation below 20 eV. For both molecules, the <5 eV shape resonances, seen experimentally and predicted by theory, do not result in fragment desorption. The main anionic fragments are H- and CN- for both molecules, additionally the fragments C-, CH- C2H- and CHN- desorb from pyrimidine and C- and C2H- from pyridazine, with some resonances lying above the ionization limit. Pyrimidine shows higher anion desorption yields than pyridazine for all species except H-. The anion signal also comprises dipolar dissociation (DD), investigated in both anionic and cationic yield functions. From analysis of anion and cation yields, fragmentation pathways are suggested. The direct ionization pathway provides information on the appearance energies for cations and their production processes in condensed phase.

Predictors of Repeated Visits to a Pediatric Emergency Department Crisis Intervention Program.

OBJECTIVES: Despite documented increases in emergency department (ED) mental health (MH) presentations, there are inconsistent findings on the characteristics of patients with repeat presentations to pediatric EDs (PEDs) for MH concerns. Our study sought to explore the characteristics of MH patients with repeat PED visits and determine predictors of return visits, of earlier repeat visits, and of more frequent repeat visits. METHODS: We examined data collected prospectively in a clinical database looking at MH presentations to a crisis intervention program housed within a PED from October 2006 to December 2011. Predictive models based on demographic and clinical variables were constructed using logistic, Cox, and negative binomial regression. RESULTS: A total of 4,080 presentations to the PED were made by the 2,900 children and youth. Repeat visits accounted for almost half (45.8%) of all presentations. Multivariable analysis identified five variables that independently predicted greater odds of having repeat presentations, greater risk of earlier repeat presentations, and greater risk of frequent repeat presentations. The five variables were: female, living in the metropolitan community close to the PED, being in the care of child protective services, taking psychotropic medications, and presenting with an actionable need in the area of mood disturbances. CONCLUSIONS: Repeat visits account for a large portion of all MH presentations to the PED. Furthermore, several patient characteristics are significant predictors of repeat PED use and of repeating use sooner and more frequently. Further research is needed to examine interventions targeting this patient group to ensure appropriate MH patient management.

Absolute cross sections for electronic excitation of condensed tetrahydrofuran (THF) by 11-16 eV electrons.

Absolute cross section (CS) data on the interaction of low energy electrons with DNA and its molecular constituents are required as input parameters in Monte-Carlo type simulations, for several radiobiological applications. Previously [V. Lemelin et al., J. Chem. Phys. 144, 074701 (2016)], we measured absolute vibrational CSs for low-energy electron scattering from condensed tetrahydrofuran, a convenient surrogate for the deoxyribose. Here we report absolute electronic CSs for energy losses of between 6 and 11.5 eV, by electrons with energies between 11 and 16 eV. The variation of these CSs with incident electron energy shows no evidence of transient anion states, consistent with theoretical and other experimental results, indicating that initial electron capture leading to DNA strand breaks occurs primarily on DNA bases or the phosphate group.

Improving mental health care transitions for children and youth: a protocol to implement and evaluate an emergency department clinical pathway.

BACKGROUND: While the emergency department (ED) is often a first point of entry for children and youth with mental health (MH) concerns, there is a limited capacity to respond to MH needs in this setting. Child MH systems are typically fragmented among multiple ministries, organizations, and providers. Communication among these groups is often poor, resulting in gaps, particularly in transitions of care, for this vulnerable population. The evidence-based Emergency Department Mental Health Clinical Pathway (EDMHCP) was created with two main goals: (1) to guide risk assessment and disposition decision-making for children and youth presenting to the ED with MH concerns and (2) to provide a streamlined transition to follow-up services with community MH agencies (CMHAs) and other providers. The purpose of this paper is to describe our study protocol to implement and evaluate the EDMHCP. METHODS/DESIGN: This mixed methods health services research project will involve implementation and evaluation of the EDMHCP in four exemplar ED-CMHA dyads. The Theoretical Domains Framework will be used to develop a tailored intervention strategy to implement the EDMHCP. A multiple baseline study design and interrupted time-series analysis will be used to determine if the EDMHCP has improved health care utilization, medical management of the MH problems, and health sector coordination. The primary process outcome will be the proportion of patients with MH-specific recommendations documented in the health record. The primary service outcome will be the proportion of patients receiving the EDMHCP-recommended follow-up at 24-h or at 7 days. Data sources will include qualitative interviews, health record audits, administrative databases, and patient surveys. A concurrent process evaluation will be conducted to assess the degree of variability and fidelity in implementation across the sites. DISCUSSION: This paper presents a novel model for measuring the effects of the EDMHCP. Our development process will identify how the EDMHCP is best implemented among partner organizations to deliver evidence-based risk management of children and youth presenting with MH concerns. More broadly, it will contribute to the body of evidence supporting clinical pathway implementation within novel partnerships. TRIAL REGISTRATION: ClinicalTrials.gov ( NCT02590302 ).

Absolute vibrational cross sections for 1-19 eV electron scattering from condensed tetrahydrofuran (THF).

Absolute cross sections (CSs) for vibrational excitation by 1-19 eV electrons impacting on condensed tetrahydrofuran (THF) were measured with a high-resolution electron energy loss spectrometer. Experiments were performed under ultra-high vacuum (3 × 10(-11) Torr) at a temperature of about 20 K. The magnitudes of the vibrational CSs lie within the 10(-17) cm(2) range. Features observed near 4.5, 9.5, and 12.5 eV in the incident energy dependence of the CSs were compared to the results of theoretical calculations and other experiments on gas and solid-phase THF. These three resonances are attributed to the formation of shape or core-excited shape resonances. Another maximum observed around 2.5 eV is not found in the calculations but has been observed in gas-phase studies; it is attributed to the formation of a shape resonance.

Electron Resonance Decay into a Biological Function: Decrease in Viability of E. coli Transformed by Plasmid DNA Irradiated with 0.5-18 eV Electrons.

Transient negative ions (TNIs) are ubiquitous in electron-molecule scattering at low electron impact energies (0-20 eV) and are particularly effective in damaging large biomolecules. Because ionizing radiation generates mostly 0-20 eV electrons, TNIs are expected to play important roles in cell mutagenesis and death during radiotherapeutic cancer treatment, although this hypothesis has never been directly verified. Here, we measure the efficiency of transforming E. coli bacteria by inserting into the cells, pGEM-3ZfL(-) plasmid DNA that confers resistance to the antibiotic ampicillin. Before transformation, plasmids are irradiated with electrons of specific energies between 0.5 and 18 eV. The loss of transformation efficiency plotted as a function of irradiation energy reveals TNIs at 5.5 and 9.5 eV, corresponding to similar states observed in the yields of DNA double strand breaks. We show that TNIs are detectable in the electron-energy dependence of a biological process and can decrease cell viability.

Non-DSB clustered DNA lesions induced by ionizing radiation are largely responsible for the loss of plasmid DNA functionality in the presence of cisplatin.

The combination of cisplatin and ionizing radiation (IR) increases cell toxicity by both enhancing DNA damage and inhibiting repair mechanisms. Although the formation of cluster DNA lesions, particularly double-strand breaks (DSB) at the site of cisplatin-DNA-adducts has been reported to induce cell death, the contribution of DSB and non-DSB cluster lesions to the cellular toxicity is still unknown. Although both lesions are toxic, it is not always possible to measure their frequency and cell survival in the same model system. To overcome this problem, here, we investigate the effect of cisplatin-adducts on the induction of DSB and non-DSB cluster DNA lesions by IR and determine the impact of such lesions on plasmid functionality. Cluster lesions are two or more lesions on opposite DNA strands with a short distance such that error free repair is difficult or impossible. At a ratio of two cisplatin per plasmid, irradiation of platinated DNA in solution with (137)Cs γ-rays shows enhancements in the formation of DNA DSB and non-DSB cluster lesions by factors of 2.6 and 2.1, respectively, compared to unmodified DNA. However, in absolute terms, the yield for non-DSB cluster lesions is far larger than that for DSB, by a factor of 26. Unmodified and cisplatin-modified DNA were irradiated and subsequently transformed into Escherichia coli to give survival curves representing the functionality of the plasmid DNA as a function of radiation dose. Our results demonstrate that non-DSB cluster lesions are the only toxic lesions present at a sufficient frequency to account for the loss of DNA functionality. Our data also show that Frank-DSB lesions are simply too infrequent to account for the loss of DNA functionality. In conclusion, non-DSB cluster DNA damage is known to be difficult to repair and is probably the lesion responsible for the loss of functionality of DNA modified by cisplatin.

Hydrated electrons react with high specificity with cisplatin bound to single-stranded DNA.

Short oligonucleotides TTTTTGTGTTT and TTTTTTTGTTT in solution with and without cisplatin (cisPt) bound to the guanine bases were irradiated with γ-rays at doses varying from 0 to 2500 Gy. To determine the effect of hydrated electrons from water radiolysis on the oligonucleotides, we quenched (•)OH radicals with ethylenediaminetetraacetic acid (EDTA) and displaced oxygen, which reacts with hydrated electrons, by bubbling the solution with wet nitrogen. DNA strand breaks and platinum detachment were quantified by gel electrophoresis. Our results demonstrate that hydrated electrons react almost exclusively at the position of the cisPt adduct, where they induce cisPt detachment from one or both guanines in the oligonucleotide. Given the high yield of hydrated electrons in irradiated tissues, this reaction may be an important step in the mechanism of radiosensitization of DNA by cisPt.

Electron stimulated desorption of anions and cations from condensed allyl glycidyl ether.

We report measurements of the electron stimulated desorption (ESD) of anions and cations from thin films of allyl glycidyl ether (AGE), formed by condensation onto multilayer Kr and Pt substrates using a high sensitivity time of flight mass analyser. Measurements were performed as a function of film thickness, incident electron energy (E(i)) and effective incident current. Below incident electron energies of 20 eV the desorption of anions is dominated by the process of dissociative electron attachment (DEA) via several transient negative ions at E(i) between 5.5 and 16.5 eV. Comparisons between measurements for AGE and ethyl oxirane show that the ESD of anions is essentially that of the glycidyl (epoxide) ring, though DEA occurring at the ether, within the linear part of the AGE molecule is also observed. Cation yields are dominated by the desorption of small fragments formed via scission of the same ether bond.

Low-energy electron-induced processes in fluorinated copper phthalocyanine films observed by F- desorption: why so little damage?

As an indication of damage induced by hot electrons in an organic electronic material, the desorption of F- ions from a thin perfluorinated copper phthalocyanide film on SiO2 under low-energy (0-25 eV) electron impact has been recorded mass spectrometrically. Yields and damage cross sections are very low. No strong features due to negative ion resonances are found in the electron energy dependence of the desorption yield; rather the yield function rises from a threshold at about 5-6 eV continuously (with some weak structure) throughout the measured range. We discuss these findings in terms of the electronic structure of the film, as well as parameters influencing the relevant bond breaking process. We emphasize the strong influence of energy redistribution, which quenches normally long-lived negative ion resonances and selects localized and strongly repulsive excitations, as often observed in electronically induced bond breaking at surfaces. The improved understanding should be helpful in the selection of low-damage materials for organic semiconductor devices and for selection of operation parameters.

Electron photoemission from charged films: absolute cross section for trapping 0-5 eV electrons in condensed CO2.

The electron trapping or attachment cross section of carbon dioxide (CO2) condensed as thin films on a spacer of Ar is obtained using a simple model for electron trapping in a molecular film and then charge releasing from the same film by photon absorption. The measurements are presented for different electron exposures and impact energies, film thicknesses, and probing photon energies. The cross section for trapping an electron of incident energy between 0 and 5 eV reveals three different attachment processes characterized by a maximum at about 0.75 eV, a structured feature around 2.25 eV, and a shoulder around 3.75 eV. From the measurement of their dependence with the probing photon energy, the two lowest processes produce traps having a vertical electron binding energy of approximately 3.5 eV, whereas the highest one yields a slightly higher value of approximately 3.7 eV. The 0.75 eV maximum corresponds to the formation of vibrational Feshbach resonances in (CO2)n- anion clusters. The 2.25 eV feature is attributed to the formation of a vibrationally excited 2Piu anion in (CO2)n- clusters, followed by fast decay into its vibrational ground state without undergoing autodetachment. Finally, 3.75 eV shoulder is assigned to the well-known dissociative electron attachment process from 2Piu anion state producing the O- anion in the gas phase and the (CO2)nO- anions in clusters.

Low-energy (3-24 eV) electron damage to the peptide backbone.

We report the mass spectrometric measurement of anions desorbed by 3-24 eV electron impact on thin films of formamide-1-d (DCONH2) and on the self-assembled monolayer (SAM) of two different Lys amide molecules used as a molecular model of the peptide backbone. In the present SAM configuration, the amides are elevated from a gold substrate by hydrocarbon chains to remove the effects of the metal substrate. Electron irradiation produces H- and D- from the formamide-1-d film and H-, CH3-, O-, and OH- from the SAM Lys amides. Below 13 eV, the dependence of the anion yields on the incident electron energy exhibits structures indicative of the dissociative electron attachment process, which is responsible for molecular fragmentation via the initial formation of core-excited anions. Above 13 eV, anion desorption is dominated principally by non-resonant dipolar dissociation. Our results suggest that the sensitivity of the peptide backbone to secondary electrons produced by ionizing radiation depends on the chemical environment (i.e., the amino acids sequence).

Validity of foot-to-foot bioelectrical impedance analysis in overweight and obese children and parents.

AIM: The aim of this study was to evaluate the validity of foot-to-foot bioelectrical impedance analysis (FF-BIA) in the measurement of body composition in overweight and obese children and their parents by comparison to dual-energy X-ray absorptiometry (DXA). METHODS: Seventeen, 7-12 year old overweight and obese children (6 boys, 11 girls) and 17 parents (5 fathers, 12 mothers) were evaluated for body composition with FF-BIA and DXA. Measures of percent body fat (PBF), fat mass (FM) and fat free mass (FFM) derived from FF-BIA and DXA were compared. Measures of validity were determined by Pearson correlations between FF-BIA and DXA, paired t-tests to assess mean differences, as well as biases and limits of agreement using the Bland Altman tests. RESULTS: FF-BIA produced estimates of body composition that were highly correlated with DXA in overweight and obese children and parents. For children, the correlations for PBF, FM, and FFM were 0.85, 0.97, and 0.94, respectively. For parents, the correlations for PBF, FM, and FFM were 0.92, 0.97, and 0.91, respectively. However, mean differences between FF-BIA and DXA were significant in children but not in parents. Bland-Altman tests of agreement showed moderate to large within-subject differences in body composition variables between FF-BIA and DXA. CONCLUSIONS: FF-BIA is strongly related to DXA in the measurement of body composition in both overweight and obese preadolescent children and parents, but the two measures may not be used interchangeably. Although FF-BIA may lack the precision to assess small changes in body composition in overweight and obese individuals, it is appropriate for epidemiological use.

Electron stimulated desorption of anionic fragments from films of pure and electron-irradiated thiophene.

The electron stimulated desorption (ESD) of anions is used to explore the effects of electron irradiation on a thiophene film and we report measurements for electron impact on multilayer thiophene condensed on a polycrystalline platinum substrate. Below 22 eV and at low electron dose, desorbed anions include H- (the dominant signal) as well as S-, CH2-, SH- and SCH2-. Yield functions show that anions are desorbed both by dissociative electron attachment (DEA) with resonances observed at 9.5, 11, and 16 eV, and for energies >13 eV, by dipolar dissociation (DD). An increase in the S- signal from electron irradiated (beam-damaged) thiophene films and the appearance of a new DEA resonance in the S- yield function at 6 eV are linked to rupture of the thiophene ring and the formation of sulfur-terminated products within the film. The threshold energy for ring rupture is 5 eV. The desorption of new anions such as C4H3S- (Thiophene-H)- is also observed from electron irradiated films and these likely arise from the decomposition of large radiation product molecules synthesized in the film. The yield functions of H-, S-, SH-, (Thiophene-H)-, and (Thiophene+H)- anions from irradiated thiophene films that have been annealed to 300 K, each exhibit a single resonant feature centered around 5.1 eV, suggesting that all signals derive from DEA to the same molecular radiation product. In contrast, only H- and S- are observed to desorb from films of 2-2-bithiophene and no resonance is seen below approximately 10 eV in the anion yield functions. These data suggest that electron irradiation causes formation of ring-opened oligomers, and that closed-ring or 'classical" oligomers, (similar to bithiophene) if formed, contribute little to the ESD of anions.

Script generation following frontal and parietal lesions.

The purpose of this investigation was to distinguish putative effects of parietal lobe lesions on script generation, in distinction from the better known and established effects of frontal lobe lesions. Nine patients, most with excised parietal lesions, were compared to nine age, gender and education matched normal participants. Eleven patients with excised tumors of the frontal lobe were compared to twelve age, gender and education matched normal subjects. Participants were requested to generate, out loud, scripts corresponding to everyday activities. Half the scripts were relatively more demanding with respect to temporal representation (understanding the time line of events) and the other half with respect to spatial representation (understanding the layout of the actions in space). These two conditions were further broken down into conditions of high and low demands on working memory (reciting the scripts backwards versus forward). The frontal lobe patients enunciated significantly fewer actions overall. They were also significantly more impaired than the normal participants on all tasks with high demands on working memory, and more often, high temporal demands (sequencing and perseverative errors). The parietal lobe patients had significant difficulty in sequencing in all conditions, and manifested no perseveration. Though script generation tasks have been primarily associated with frontal lobe function until now, consideration should be given to the type of activity being scripted as a function of relative demands on spatial or temporal representation, as well as working memory, and the contributions of other lobes ought to be taken into consideration.

Dissociative electron attachment to DNA.

Electron-stimulated desorption of anions from thin films of linear and supercoiled DNA is investigated in the range 3-20 eV. Resonant structures are observed with maxima at 9.4+/-0.3, 9.2+/-0.3, and 9.2+/-0.3 eV, respectively, in the yield dependence of H-, O-, and OH- on the incident electron energy. Their formation is attributed to dissociative electron attachment.