Excitation energies, photoionization cross sections, and asymmetry parameters of the methyl and silyl radicals.

Vertical excitation energies of the methyl and silyl radicals were inferred from ab initio electron propagator calculations on the electron affinities of CH3(+) and SiH3(+). Photoionization cross sections and angular distribution of photoelectrons for the outermost orbitals of both CH3 and SiH3 radicals have been obtained with the Molecular Quantum Defect Orbital method. The individual ionization cross sections corresponding to the Rydberg channels to which the excitation of the ground state's outermost electron gives rise are reported. Despite the relevance of methyl radical in atmospheric chemistry and combustion processes, only data for the photon energy range of 10-11 eV seem to be available. Good agreement has been found with experiment for photoionization cross section of this radical. To our knowledge, predictions of the above mentioned photoionization parameters on silyl radical are made here for the first time, and we are not aware of any reported experimental measurements. An analysis of our results reveals the presence of a Cooper minimum in the photoionization of the silyl radical. The adequacy of the two theoretical procedures employed in the present work is discussed.

Photoionization cross sections and asymmetry parameters for the valence shell of methanol.

Theoretical cross sections for photoionization of the methanol valence orbitals in covering a region up to 80 eV beyond the first ionization potential are reported. The molecular quantum defect orbital, MQDO, method, which has proved to be reliable in previous applications to molecular photoionization, has been used. To our knowledge, predictions of electronic partial cross section profiles on this molecule are made here for the first time, and we are not aware of any reported experimental data. Partial cross sections for production of parent and fragment ions of methanol have also been calculated and compared with previous measurements. In addition, the MQDO method has been used to calculate the angular distribution of photoelectrons for the valence orbitals of methanol over the 11-50 eV photon energy range. Our results are compared with experimental data, showing a good agreement in most cases. We hope that the present results might be of use in atmospheric and interstellar chemistry, where this molecule plays an important role.

Angular distribution of photoelectrons in small molecules: a molecular quantum defect calculation.

The molecular quantum defect orbital (MQDO) method, previously used in the determination of molecular photoionization cross sections, is applied here to calculate the angular distribution of photoelectrons arising from the molecular photoionization. Calculations are performed for the ionization from outer valence orbitals of HF, H(2)O, NH(3), N(2)O, and H(2)CO molecules. The results are compared with previous measurements and with theoretical curves found in the literature. Profiles of the angular distribution parameter as a function of photoelectron energy covering a range from the photoionization threshold to 120 eV are presented for the above molecules. The energy dependence of the angular distributions predicted by the MQDO calculations agrees fairly well with predictions from more sophisticated theories and with observed results.

The electronic spectrum of SiH4: Jahn-Teller Rydberg series.

The aim of the present theoretical work is to provide data necessary for a better understanding of the electronic spectrum of the silane molecule, which is affected by the Jahn-Teller effect. By selecting an adequate distorted C(2v) geometry of SiH(4), the three lower Koopmans ionization potentials are evaluated with the equation of motion coupled cluster of singles and doubles method. Vertical excitation energies for the different Rydberg series converging to the three Jahn-Teller components are inferred from ab initio coupled cluster linear response calculations. Absorption oscillator strengths for dipole-allowed electronic transitions are also determined with the molecular-adapted quantum defect orbital methodology. Predictions of new spectroscopic data on SiH(4) are reported.

Absorption oscillator strengths for vibronic transitions of nppi Rydberg series in NO.

The vibronic intensities for band systems of NO corresponding to transitions with origin in both the X(2)Pi ground and the 3ssigma(A(2)Sigma(+)) Rydberg states, and ending in the nppi Rydberg series with n = 3-5, have been determined. The description of the Rydberg states has been made with the molecular quantum defect orbital methodology. The Rydberg-valence interaction of the (2)Pi symmetry states involved in the studied transitions has been analyzed through a vibronic matrix. The present results have been compared with experimental and theoretical data available in the literature. Additionally, predictions for a number of unknown intensities have been made, which may be useful for the interpretation of the spectrum of NO.

Partial photoionization cross sections of NH4 and H3O Rydberg radicals.

Photoionization cross sections for various Rydberg series that correspond to ionization channels of ammonium and oxonium Rydberg radicals from the outermost, occupied orbitals of their respective ground states are reported. These properties are known to be relevant in photoelectron dynamics studies. For the present calculations, the molecular-adapted quantum defect orbital method has been employed. A Cooper minimum has been found in the 3sa(1)-kpt(2) Rydberg channel of NH(4) beyond the ionization threshold, which provides the main contribution to the photoionization of this radical. However, no net minimum is found in the partial cross section of H(3)O despite the presence of minima in the 3sa(1)-kpe and 3sa(1)-kpa(1) Rydberg channels. The complete oscillator strength distributions spanning the discrete and continuous regions of both radicals exhibit the expected continuity across the ionization threshold.

Theoretical study of spectral intensities of formaldehyde in the discrete and continuum regions.

Theoretical absorption oscillator strengths for transitions involving Rydberg states in molecular formaldehyde as well as cross sections for photoionization Rydberg channels associated with the production of the lowest parent ion electronic state are reported. The calculations have been performed with the molecular quantum defect orbital (MQDO) method. A test on the MQDO f values has been its comparison with previous experiments and calculations and its compliance with the expected systematic trends along the Rydberg series. The use of the MQDO method as an alternative to ab initio methods, which find serious difficulties in calculating spectral intensities in formaldehyde, is proposed. We hope that the spectroscopic data, many of them reported here for the first time, may be useful for the interpretation of the vacuum ultraviolet spectrum of this molecule.

Low-lying Rydberg states of HCl.

Vertical excitation energies belonging to some different Rydberg series of hydrogen chloride have been determined with a coupled-cluster theoretical approach. These excitation energies have allowed us to calculate electric dipole transition intensities in HCl and allow additional assessment of the calculation approach presently used to provide an adequate description of the valence and Rydberg states of HCl. The molecular quantum defect orbital has been applied to the calculation of oscillator strengths. In particular, new insight is given on the assignment of states as the R1Pi, the 1Delta(4dpi and 5ppi), the 1Sigma+(4dpi), and the nddelta(1Pi, 1Phi) and 4f states.

Categorización diagnóstica del síndrome postaborto / Diagnostic categorization of post-abortion syndrome

Actualmente todavía se observa cierta resistencia a reconocer como entidad nosológica diferenciada a un cuadro psicopatológico conocido como síndrome postaborto (SPA) descrito en mujeres que se han provocado un aborto. Con el objetivo de asignar categoría diagnóstica al SPA se investiga hasta qué punto una muestra de pacientes con dicho diagnóstico cumple los criterios diagnósticos de las clasificaciones internacionales. En los 10 casos de SPA estudiados se cumplen los criterios diagnósticos de trastorno de estrés postraumático (TEPT). Además, las pacientes con SPA presentan algunos síntomas de especial interés cualitativo, como reiterados y persistentes sueños y pesadillas relacionados con el aborto, intensos sentimientos de culpa y la «necesidad de reparar». El SPA debe considerarse un tipo más de TEPT, aunque con características propias muy relevantes a la hora de la comprensión vivencial de la paciente de la intervención psicoterapéutica

Some psychopathological characteristics are frequently observed in women who have voluntarily aborted. However, some resistance currently remains to their recognition as a differentiated nosological category, known as Post-Abortion Syndrome (PAS). We tried to assign a diagnostic category to women with PAS by determining the extent by which they fulfilled the diagnostic criteria of international classifications. Criteria for Post-Traumatic Stress Disorder (PTSD) were met in the ten PAS cases studied. In addition, patients also showed other non-specific symptoms such as repeated and persistent dreams and nightmares related with the abortion, intense feelings of guilt and the «need to repair». PAS should be considered as an additional type of PTSD. It also has some specific characteristics that could help to understand the patient’s life experience and to establish a psychotherapeutic intervention

Diagnostic categorization of post-abortion syndrome.

Some psychopathological characteristics are frequently observed in women who have voluntarily aborted. However, some resistance currently remains to their recognition as a differentiated nosological category, known as Post-Abortion Syndrome (PAS). We tried to assign a diagnostic category to women with PAS by determining the extent by which they fulfilled the diagnostic criteria of international classifications. Criteria for Post-Traumatic Stress Disorder (PTSD) were met in the ten PAS cases studied. In addition, patients also showed other non-specific symptoms such as repeated and persistent dreams and nightmares related with the abortion, intense feelings of guilt and the "need to repair". PAS should be considered as an additional type of PTSD. It also has some specific characteristics that could help to understand the patient's life experience and to establish a psychotherapeutic intervention.

Ground and excited states of the Rydberg radical H3O: electron propagator and quantum defect analysis.

Vertical excitation energies of the Rydberg radical H(3)O are inferred from ab initio electron propagator calculations on the electron affinities of H(3)O(+). The adiabatic ionization energy of H(3)O is evaluated with coupled-cluster calculations. These predictions provide optimal parameters for the molecular-adapted quantum defect orbital method, which is used to determine oscillator strengths. Given that the experimental spectrum of H(3)O does not seem to be available, comparisons with previous calculations are discussed. A simple model Hamiltonian, suitable for the study of bound states with arbitrarily high energies is generated by these means.

Ground and excited states of NH4: Electron propagator and quantum defect analysis.

Vertical excitation energies of the Rydberg radical NH4 are inferred from ab initio electron propagator calculations on the electron affinities of NH4+. The adiabatic ionization energy of NH4 is evaluated with coupled-cluster calculations. These predictions provide optimal parameters for the molecular-adapted quantum defect orbital method, which is used to determine Einstein emission coefficients and radiative lifetimes. Comparisons with spectroscopic data and previous calculations are discussed.

Clients' perceptions of the benefits of reflexology on their quality of life.

Awareness has increased among health-care professionals, patients and the general public of the importance of an holistic approach to cancer care. Psychosocial interventions, including complementary therapies, may help to improve the quality of life (QoL) of people with cancer by helping to reduce the distress associated with the diagnosis and treatment of cancer and by facilitating improved psychological adjustment to the experience of cancer. The following article presents anecdotal findings at ARC Cancer Support Centre Dublin, Ireland, of clients' perceptions of the benefits of reflexology interventions on their QoL. Reflexology interventions were perceived to impact positively upon clients' levels of impairment and functional status, including physical and psychological function, with implications for general health perceptions. The paper discusses how these findings might form the basis of further, more rigourous evaluation of the benefits of reflexology for people with cancer at ARC Cancer Support Centre.

Activation of flavin-containing oxidases underlies light-induced production of H2O2 in mammalian cells.

Violet-blue light is toxic to mammalian cells, and this toxicity has been linked with cellular production of H2O2. In this report, we show that violet-blue light, as well as UVA, stimulated H2O2 production in cultured mouse, monkey, and human cells. We found that H2O2 originated in peroxisomes and mitochondria, and it was enhanced in cells overexpressing flavin-containing oxidases. These results support the hypothesis that photoreduction of flavoproteins underlies light-induced production of H2O2 in cells. Because H2O2 and its metabolite, hydroxyl radicals, can cause cellular damage, these reactive oxygen species may contribute to pathologies associated with exposure to UVA, violet, and blue light. They may also contribute to phototoxicity often encountered during light microscopy. Because multiphoton excitation imaging with 1,047-nm wavelength prevented light-induced H2O2 production in cells, possibly by minimizing photoreduction of flavoproteins, this technique may be useful for decreasing phototoxicity during fluorescence microscopy.

The cellular mechanism of epithelial rearrangement during morphogenesis of the Caenorhabditis elegans dorsal hypodermis.

The mechanism by which epithelial cells rearrange is a process that is central to epithelial morphogenesis, yet remains poorly understood. We have investigated epithelial cell rearrangement in the dorsal hypodermis of the Caenorhabditis elegans embryo, in which two rows of epithelial cells rearrange in a morphogenetic process known as dorsal intercalation. The intercalating cells extend basal protrusions which squeeze between their opposing neighbors beneath their adherens junctions. As the intercalating cells move forward, these protruding tips become broader in the anterior-posterior and dorsoventral dimensions, effectively "plowing through" the adherens junctions and forcing an opening for the remainder of the intercalating cell to insert between the contralateral cells. These cell movements are dependent upon intact cytoarchitecture, since the pharmacological disruption of microtubules or actin filaments blocks cell rearrangement. The cells appear to intercalate independently of immediately adjacent neighboring hypodermal cells because dorsal intercalation is not blocked by the ablation of the progenitors for either half of the lateral hypodermal cells or the posterior half of the dorsal hypodermis. This is the first case in which the protrusive mechanism underlying epithelial cell rearrangement has been characterized, and we propose a model describing how epithelial cells rearrange within the confines of an epithelial monolayer, and discuss the mechanisms that may be guiding these directed cell movements.

Creating statewide tobacco control programs after passage of a tobacco tax: executive summary.

The tobacco control leaders of four states that have successfully passed tobacco tax ballot initiatives (California, Massachusetts, Arizona, and Oregon) were brought together to this conference to discuss what happens after the passage of such an initiative, how to defend tobacco control funds against diversion for other purposes by a state's legislature, and how to use the revenues maximally to reduce the health and economic toll taken by tobacco use. At the conference, the attendees from each state presented reports that will undoubtedly be useful to other states seeking to pass their own tobacco tax legislation or initiatives.

Getting key players to work together and defending against diversion--Massachusetts.

In this report, the authors trace the development of an effective statewide tobacco control program following victory at the Massachusetts polls in 1992. They examine the pitfalls standing in the way of coalition building and present important lessons for states in similar positions.

Follow-up of abnormal Papanicolaou smears in a hospital-based adolescent clinic.

STUDY OBJECTIVE: To present data on the spectrum of abnormal Papanicolaou (PAP) smears in adolescents and to determine factors that influence compliance with recommendations to return for repeat PAP smears or for colposcopic examination. DESIGN: Retrospective chart review with follow-up telephone calls to patients who did not follow recommendations for colposcopy. SETTING: Adolescents receiving health care in a hospital-based adolescent clinic. PARTICIPANTS: Patients with abnormal PAP smears between July 1, 1994 and June 30, 1995. MAIN OUTCOME MEASURES: Compliance with follow-up for abnormal PAP smears including referral to the colposcopy clinic, and the results of repeat PAP smears and colposcopy. RESULTS: Of 888 adolescents undergoing PAP smear evaluation 119 (13.4%) had an abnormal PAP smear during the study year (index PAP). The results of the index PAP were 97 (81.5%) atypia and 22 (18.5%) squamous intraepithelial lesion low grade (SIL LG). The index PAP was the first abnormal PAP smear for 92 of the patients (77%); 27 had one or more previous abnormal PAP smears (18 atypia, 7 SIL LG, 2 SIL high grade [HG]), and 13 had been referred for colposcopy in the past. For 76 of 92 patients with atypia on index PAP (84%), the index PAP was the first abnormal PAP smear. Of these 76 patients, 51 had a second PAP smear: 27 (53%) were normal, 13 (25%) atypia, and 11 (22%) SIL LG. Sixty patients were referred to the colposcopy clinic, but only 37 actually kept the colposcopy appointment despite outreach. The only significant factor for obtaining colposcopy was a visit to the Adolescent Clinic after notification of the abnormal PAP smear result and before the colposcopy appointment; 79% of those who had a visit obtained colposcopy compared with 45% of those who did not have such a visit (p = 0.007). There were no significant differences by race, insurance status, age, PAP smear result, previous referral for colposcopy, or number of reminders with compliance with recommendations for repeat PAP smears or colposcopy. CONCLUSIONS: Although a sizable proportion of adolescents with abnormal PAP smears have significant pathology on repeat PAP smears, adolescents with abnormal PAP smears have a high failure rate in keeping appointments for follow-up PAP smears and colposcopy. Interventions that target all adolescents with abnormal PAP smears need to be designed and tested to aid follow-up.

Comparative ultrastructure of plasmodesmata of Chara and selected bryophytes: toward an elucidation of the evolutionary origin of plant plasmodesmata.

We have used transmission electron microscopy to examine plasmodesmata of the charophycean green alga Chara zeylanica, and of the putatively early divergent bryophytes Monoclea gottschei (liverwort), Notothylas orbicularis (hornwort), and Sphagnum fimbriatum (moss), in an attempt to learn when seed plant plasmodesmata may have originated. The three bryophytes examined have desmotubules. In addition, Monoclea was found to have branched plasmodesmata, and plasmodesmata of Sphagnum displayed densely staining regions around the neck region, as well as ring-like wall specializations. In Chara, longitudinal sections revealed endoplasmic reticulum (ER) that sometimes appeared to be associated with plasmodesmata, but this was rare, despite abundant ER at the cell periphery. Across all three fixation methods, cross-sectional views showed an internal central structure, which in some cases appeared to be connected to the plasma membrane via spoke-like structures. Plasmodesmata were present even in the incompletely formed reticulum of forming cell plates, from which we conclude that primary plasmodesmata are formed at cytokinesis in Chara zeylanica. Based on these results it appears that plasmodesmata of Chara may be less specialized than those of seed plants, and that complex plasmodesmata probably evolved in the ancestor of land plants before extant lineages of bryophytes diverged.

Scores on the Wechsler Intelligence Scale for Children-Third Edition and Woodcock-Johnson Tests of Achievement-Revised for a sample of children with emotional handicaps.

Because there is little available research, this study examined the associations between scores on the Wechsler Intelligence Scale for Children-Third Edition and the Woodcock-Johnson Tests of Achievement-Revised for 85 children with diagnosed emotional handicaps. Analysis indicated associations were significant.