Giant magnetothermopower of magnon-assisted transport in ferromagnetic tunnel junctions

We present a theoretical description of the thermopower due to magnon-assisted tunneling in a mesoscopic tunnel junction between two ferromagnetic metals. The thermopower is generated in the course of thermal equilibration between two baths of magnons, mediated by electrons. For a junction between two ferromagnets with antiparallel polarizations, the ability of magnon-assisted tunneling to create thermopower $S_{AP}$ depends on the difference between the size $\Pi_{\uparrow, \downarrow}$ of the majority and minority band Fermi surfaces and it is proportional to a temperature dependent factor $(k_{B}T/\omega_{D})^{3/2}$ where $\omega_{D}$ is the magnon Debye energy. The latter factor reflects the fractional change in the net magnetization of the reservoirs due to thermal magnons at temperature $T$ (Bloch's $T^{3/2}$ law). In contrast, the contribution of magnon-assisted tunneling to the thermopower $S_P$ of a junction with parallel polarizations is negligible. As the relative polarizations of ferromagnetic layers can be manipulated by an external magnetic field, a large difference $\Delta S = S_{AP} - S_P \approx S_{AP} \sim - (k_B/e) f (\Pi_{\uparrow},\Pi_{\downarrow}) (k_BT/\omega_{D})^{3/2}$ results in a magnetothermopower effect. This magnetothermopower effect becomes giant in the extreme case of a junction between two half-metallic ferromagnets, $\Delta S \sim - k_B/e$.Comment: 9 pages, 4 eps figure

Genetic variability in the Skyros pony and its relationship with other Greek and foreign horse breeds

In Greece, seven native horse breeds have been identified so far. Among these, the Skyros pony is outstanding through having a distinct phenotype. In the present study, the aim was to assess genetic diversity in this breed, by using different types of genetic loci and available genealogical information. Its relationships with the other Greek, as well as foreign, domestic breeds were also investigated. Through microsatellite and pedigree analysis it appeared that the Skyros presented a similar level of genetic diversity to the other European breeds. Nevertheless, comparisons between DNA-based and pedigree-based results revealed that a loss of genetic diversity had probably already occurred before the beginning of breed registration. Tests indicated the possible existence of a recent bottleneck in two of the three main herds of Skyros pony. Nonetheless, relatively high levels of heterozygosity and Polymorphism Information Content indicated sufficient residual genetic variability, probably useful in planning future strategies for breed conservation. Three other Greek breeds were also analyzed. A comparison of these with domestic breeds elsewhere, revealed the closest relationships to be with the Middle Eastern types, whereas the Skyros itself remained isolated, without any close relationship, whatsoever

Downregulation of FIP200 Induces Apoptosis of Glioblastoma Cells and Microvascular Endothelial Cells by Enhancing Pyk2 Activity

The expression of focal adhesion kinase family interacting protein of 200-kDa (FIP200) in normal brain is limited to some neurons and glial cells. On immunohistochemical analysis of biopsies of glioblastoma tumors, we detected FIP200 in the tumor cells, tumor-associated endothelial cells, and occasional glial cells. Human glioblastoma tumor cell lines and immortalized human astrocytes cultured in complete media also expressed FIP200 as did primary human brain microvessel endothelial cells (MvEC), which proliferate in culture and resemble reactive endothelial cells. Downregulation of endogenous expression of FIP200 using small interfering RNA resulted in induction of apoptosis in the human glioblastoma tumor cells, immortalized human astrocytes, and primary human brain MvEC. It has been shown by other investigators using cells from other tissues that FIP200 can interact directly with, and inhibit, proline-rich tyrosine kinase 2 (Pyk2) and focal adhesion kinase (FAK). In the human glioblastoma tumor cells, immortalized human astrocytes, and primary human brain MvEC, we found that downregulation of FIP200 increased the activity of Pyk2 without increasing its expression, but did not affect the activity or expression of FAK. Coimmunoprecipitation and colocalization studies indicated that the endogenous FIP200 was largely associated with Pyk2, rather than FAK, in the glioblastoma tumor cells and brain MvEC. Moreover, the pro-apoptotic effect of FIP200 downregulation was inhibited significantly by a TAT-Pyk2-fusion protein containing the Pyk2 autophosphorylation site in these cells. In summary, downregulation of endogenous FIP200 protein in glioblastoma tumor cells, astrocytes, and brain MvECs promotes apoptosis, most likely due to the removal of a direct interaction of FIP200 with Pyk2 that inhibits Pyk2 activation, suggesting that FIP200 expression may be required for the survival of all three cell types found in glioblastoma tumors

Exploring silence in short-term psychoanalytic psychotherapy with adolescents with depression

Psychotherapy process research is important in developing technique and enhancing clinical skills. Silence, as an aspect of child and adolescent psychoanalytic psychotherapy, has been a neglected area of research, despite it being acknowledged as an often challenging yet therapeutically useful aspect of the work. This study aims to explore silence in adolescent psychoanalytic psychotherapy, by studying the emergence of silence in therapy sessions. Three Short-Term Psychoanalytic Psychotherapies of adolescents with depression were used in the study, and silences occurring in six sessions of each therapy were coded, using the Pausing Inventory Categorization System (PICS). Findings showed that, in the three therapies sampled, almost one-third of session time was spent on average in silence, and most of this silence was coded as ‘obstructive’. Moreover, the amount of silence in every stage of therapy was different for each patient-therapist dyad. Follow-up interviews conducted with the adolescents were analysed using thematic analysis, and showed that the adolescents generally expressed negative feelings about silence in their therapy. Analysis suggests that the majority of the silence in these therapies related to conflict, which could be viewed as both an aspect of the developmental stage of adolescence, and a symptom of depression. These findings suggest that silences may not always be therapeutically productive in adolescent therapy, even if they are considered to be so in psychotherapy with adults, and so adaptations in therapeutic technique are required

Evaluating the therapeutic use of photocards in European prisons

This paper focuses on the evaluation of the therapeutic use of photocards by prisoners and facilitators in a counselling psychology led European project, based on responses to open-ended questionnaires. It is part of a wider project, involving seven partner organisations in six European countries (England, Finland, Greece, Italy, Malta and Romania), which developed and trialled four different approaches to using photography in the context of counselling in prisons. Of the 51 inmates that participated in the project, 48 (94%) completed the questionnaires; of those, 39 (77%) were available for individual analysis due to prison restrictions in one partner organisation only allowing group data. Of those 39, who returned their completed questionnaires, over 92% found the therapeutic use of photographs either very helpful (56.4%) or helpful (35.9%), and the remaining 7.7% described it as average. From the thematic analysis, main themes emerging regarding inmates’ experiences of working with photocards were that it: facilitates emotional expression and sharing; unlocks memories and reconnects with life outside; fosters insight, reflection and self-growth; breaks the monotony of prison life and, overall aids emotional learning. A thematic analysis of 11 psychological therapists/facilitators’ perspectives showed that the use of photocards: gives clients a voice; provides a safe and collaborative frame and a therapeutic relationship; and, provides a useful icebreaker, helpfully overcoming anxieties of both client and psychotherapist/facilitator. Overall, photocards were considered useful as their projective nature can help facilitate prisoners’ strong need for expression in a context where there are limited opportunities and trust is fragile. © 2016 Informa UK Limited, trading as Taylor & Francis Group