Lipoxygenase activity associated to fruit ripening and senescence in chayote (Sechium edule Jacq. Sw. cv. “virens levis”)

Lipoxygenase (LOX) enzyme activity and their putative isoforms were investigated during postharvest life in chayote fruit (Sechium edule Jacq. Sw. cv. “virens levis”). Possible associations of LOX with fruit quality parameters are discussed. Five LOX isoforms were identified (SeLOX‐1 to ?5) displaying different activity patterns during ripening and senescence as well as in roots, stems, and leaves. The probable role of SeLOX‐5 as a specific isoform linked to senescence was examined. The highest relative activity of LOX was registered in fruit tissue, followed by leaves, stem, and roots. Correlations were found between LOX and fruit composition variables such as the contents of linoleic (LA) and linolenic (LNA) acids, weight loss, CO₂ and ethylene production rates. LOX activity, and LA and LNA concentration decreased from Day 1 to Days 13–17, when early seed germination events became visible, indicating a transition stage between late fruit ripening and early senescence characterized by a deteriorative process.

Practical applications

Detrimental effects on fruit composition variables such as dehydration, weight loss, wilting, and sprouting symptoms, have been reported as the main causes that reduce the commercial quality and shelf life in chayote fruit and prevent their export to distant markets. To the best of our knowledge, the association of lipoxygenase (LOX) enzymes to non‐climacteric fruit ripening—like chayote—or their loss of commercial quality during prolonged shelf life has not yet been described. This is the first study that explores the role of chayote LOX activity in fruit, identifies various specific LOX isoforms associated to ripening or to the senescence process and provides new evidence that supports the hypothesis that putative LOX isoforms might be related to several postharvest detrimental effects on chayote fruit. This information could be useful to food processors or packers to pursue better profitability and consumer satisfaction.     

Kinetic and Mechanistic Study of Ozonation of Three Dichlorophenols in Aqueous Solutions

This research investigates the kinetic parameters associated with the ozonation of 2,3-, 2,4-, and 2,5-dichlorophenols (DCPs) in aqueous solutions at 25°C. The overall ozonation kinetics of each DCP was found to be first order with respect to each reactant concentration (i.e., DCP and ozone). Among the three isomers studied, the ozonation of 2,5-DCP was the fastest with the overall rate constant varying from 68,500 to 7,750,000 M?1 s?1 within a pH range of 2.1 to 5.0. The overall rate constant increased with pH because of the increase in the degree of dissociation of the DCP molecules to dichlorophenoxide ions. The electrophilic addition of ozone at the ortho and para positions of the molecular and ionic forms of the DCPs was postulated to be the likely mechanism for the degradation of the DCPs to chlorobenzenediols, monochlorophenols, chlorocyclohexadienediones, ethylacetate, heptanone, carboxylic acids, and other by-products that were detected using gas chromatograph∕mass spectrometry analysis.     

Adjunctive psychotherapy for bipolar disorder: Effects of changing treatment modality.

In a randomized, controlled trial, the authors studied an adjunctive, individual psychotherapy, interpersonal and social rhythm therapy (IPSRT) for bipolar disorder. After stabilizing participants with episode appropriate pharmacotherapy and either IPSRT or intensive clinical management (CM), participants were reassigned to IPSRT or CM in conjunction with pharmacotherapy for 2 years of preventative treatment. Early results (n?=?82) suggest that altering participants' treatment assignment at entry to the preventative phase is related to risk of recurrence. Participants remaining in the same treatment for both acute and preventative phases had lower rates of recurrence (40%) and levels of symptomatology over the subsequent 52 weeks than those reassigned to the alternate modality. This finding, consistent with the authors' philosophy that bipolar patients benefit from stable routines, suggests that disruptions in the psychosocial treatment plan contribute to worse outcomes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Mechanisms of reorientation and object localization by children: A comparison with rats.

Neurophysiological studies show that the firing of place and head-direction (HD) cells in rats can become anchored to features of the perceptible environment, suggesting that those features partially specify the rat's position and heading. In contrast, behavioral studies suggest that disoriented rats and human children rely exclusively on the shape of their surroundings, ignoring much of the information to which place and HD cells respond. This difference is explored in the current study by investigating young children's ability to locate objects in a square chamber after disorientation. Children 18–24 months old used a distinctive geometric cue but not a distinctively colored wall to locate the object, even after they were familiarized with the colored wall. Results suggest that the spatial representations underlying reorientation and object localization are common to humans and other mammals. Together with the neurophysiological findings, these experiments raise questions for the hypothesis that hippocampal place and HD cells serve as a general orientation device for target localization. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A randomized trial of cognitive therapy and imaginal exposure in the treatment of chronic posttraumatic stress disorder.

A randomized trial was performed in which imaginal exposure (IE) and cognitive therapy (CT) were compared in the treatment of chronic posttraumatic stress disorder (PTSD). Patients who continued to meet PTSD caseness at the end of a 4-week symptom-monitoring baseline period (n?=?72) were randomly allocated to either IE or CT. There was a significant improvement in all measures over treatment and at follow-up, although there were no significant differences between the 2 treatments at any assessment. A significantly greater number of patients who showed worsening over treatment received IE, although this effect was not found at follow-up. Patients who worsened showed a greater tendency to miss treatment sessions, rated therapy as less credible, and were rated as less motivated by the therapist. It was concluded that either exposure or a challenge to cognition can result in symptom reduction, although neither resulted in complete improvement. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Dream interpretation and false beliefs.

Dream interpretation is a common practice in psychotherapy. In the research presented in this article, each participant saw a clinician who interpreted a recent dream report to be a sign that the participant had had a mildly traumatic experience before age 3 years, such as being lost for an extended time or feeling abandoned by his or her parents. This dream intervention caused a majority of participants to become more confident that they had had such an experience, even though they had previously denied it. These findings have implications for the use of dream material in clinical settings. In particular, the findings point to the possibility that dream interpretation may have unexpected side effects if it leads to beliefs about the past that may, in fact, be false. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Obituary: Ursula Marie Delworth (1934-2000).

Memorializes Ursula Marie Delworth, known for her work on outreach, community models of mental health and service delivery, and training and supervision. She coupled her research interests with a commitment to issues of justice and equality and to the advancement of unempowered and disenfranchised people. She advocated strongly for the promotion of women in academe, and as chair of a committee on the subject analyzed the climate for women in academe and developed significant concrete remedies that are still being implemented. She served as the third woman president of APA's Division 17 (Counseling Psychology). (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Spiritual issues in counseling: Clients' beliefs and preferences.

The current study assessed psychotherapy clients' beliefs about the appropriateness of discussing religious and spiritual concerns in counseling, clients' preferences for such discussion, and identified explanatory variables for these beliefs and preferences. These variables were assessed using the Client Attitudes toward Spirituality in Therapy survey; the Index of Spiritual Experiences (J. D. Kass, R. Friedman, J. Leserman, P. C. Zuttermeister, & H. Benson, 1991); the Expectations About Counseling-Brief Form (H. E. A. Tinsley, 1982); the Religious scale of the Counseling Appropriateness Check List (R. Warman, 1960); the Socially Desirable Response Set-5 Scale (R. D. Hays, T. Hayashi, & A. L. Stewart, 1989); and the Religion Section of the Mooney Problem Check List-Adult Form (L. V. Gordon & R. L. Mooney, 1950). Clients believed religious concerns were appropriate for discussion in counseling and had a preference for discussing spiritual and religious issues in counseling. Spiritual experience was the most potent variable for explaining preferences for discussing spiritual issues. Implications and limitations of the study are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Modulation of the attentional blink by differential resource allocation.

When one masked target (T2) follows another (T1) in close temporal proximity, identification accuracy of the second target is reduced for a period referred to as the attentional blink. Analysis of the attentional blink literature suggests that increasing the difficulty of T1 processing increases the magnitude of the blink. In a previous study that eliminated several untoward features of the typical attentional blink design (e.g., task switching, location switching, and stream contribution), we found no effect on blink magnitude when three levels of T1 difficulty (manipulated in a data-limited manner) were randomly intermixed. Here, when we repeated the previous study, with 20 college students, using a blocked manipulation of T1 difficulty, which is characteristic of the literature, a significant positive relation between T1 difficulty and blink magnitude was found. Resource allocation put in place to encode T1 in advance of a dual-target trial thus seems to be the critical factor in mediating this relation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)