Short-range charge-order in RRNiO3_{3} perovskites (RR=Pr,Nd,Eu) probed by X-ray absorption spectroscopy

The short-range organization around Ni atoms in orthorhombic $R$NiO$_{3}$ ($R$=Pr,Nd,Eu) perovskites has been studied over a wide temperature range by Ni K-edge x-ray absorption spectroscopy. Our results demonstrate that two different Ni sites, with different average Ni-O bond lengths, coexist in those orthorhombic compounds and that important modifications in the Ni nearest neighbors environment take place across the metal-insulator transition. We report evidences for the existence of short-range charge-order in the insulating state, as found in the monoclinic compounds. Moreover, our results suggest that the two different Ni sites coexists even in the metallic state. The coexistence of two different Ni sites, independently on the $R$ ion, provides a common ground to describe these compounds and shed new light in the understanding of the phonon-assisted conduction mechanism and unusual antiferromagnetism present in all $R$NiO$_{3}$ compounds.Comment: 4 pages, 3 figures, accepted PRB - Brief Report Dec.200

Curricular Practices of Selected Tertiary Private-Sectarian Institutions

Gap between curricular practice and the idealism in the goals of education exists. This study evaluated the status of the curricular practices of selected tertiaryprivate-sectarian institutions using the Context, Input, Process, and Product (CIPP)evaluation model and answered the following research questions: (1) What is thestatus of the curricular practices of the selected tertiary private-sectarian institutionsas evaluated by the school administrators, faculty, staff, and students in terms of thefollowing: (a) goals and objectives; (b)faculty qualifications and performance; (c)on program of studies and curriculum; (d)teaching methodologies, techniques andassessments (f) values practice and integration(g) library services; (h) communityservices and social awareness; (f) research. (2) Is there a significant difference onthe assessments of the three groups of respondents as to the above-mentionedvariables? (3) What factors hinder and facilitate the implementation of thecurricular practices in the selected tertiary private-sectarian institutions? Usingdescriptive method, data were gathered from 207 respondents from three tertiaryAdventist schools in the Philippines, namely the Northern Luzon Adventist College(NLAC), the Northeast Luzon Adventist College (NELAC), and the North VisayanAdventist College. The findings reveal that the curricular practices for all threegroups, namely the administrators, the faculty, and the students were generally ratedas implemented. There is significant difference on the evaluation of the threegroups of respondents on goals and objectives; on teaching methodologies,techniques, and assessments; on values practice and integration; on library services;on community extension services and social awareness. There is no significantdifference though on faculty qualifications and performance; on program of studiesand curriculum; and the dissemination and relevance of research. The factors that hinder the implementation of the curricular practices include among others: a) weakresearch; b) need for the tertiary private-sectarian institutions to hire and train young faculty members

Role of STAT3 in Transformation and Drug Resistance in CML

Chronic myeloid leukemia (CML) is initially driven by the bcr–abl fusion oncoprotein. The identification of bcr–abl led to the discovery and rapid translation into the clinic of bcr–abl kinase inhibitors. Although, bcr–abl inhibitors are efficacious, experimental evidence indicates that targeting bcr–abl is not sufficient for elimination of minimal residual disease found within the bone marrow (BM). Experimental evidence indicates that the failure to eliminate the leukemic stem cell contributes to persistent minimal residual disease. Thus curative strategies will likely need to focus on strategies where bcr–abl inhibitors are given in combination with agents that specifically target the leukemic stem cell or the leukemic stem cell niche. One potential target to be exploited is the Janus kinase (JAK)/signal transducers and activators of transcription 3 (STAT3) pathway. Recently using STAT3 conditional knock-out mice it was shown that STAT3 is critical for initiating the disease. Interestingly, in the absence of treatment, STAT3 was not shown to be required for maintenance of the disease, suggesting that STAT3 is required only in the tumor initiating stem cell population (Hoelbl et al., 2010). In the context of the BM microenvironment, STAT3 is activated in a bcr–abl independent manner by the cytokine milieu. Activation of JAK/STAT3 was shown to contribute to cell survival even in the event of complete inhibition of bcr–abl activity within the BM compartment. Taken together, these studies suggest that JAK/STAT3 is an attractive therapeutic target for developing strategies for targeting the JAK–STAT3 pathway in combination with bcr–abl kinase inhibitors and may represent a viable strategy for eliminating or reducing minimal residual disease located in the BM in CML

The Relationship Among Adult Attachment Styles, Shame, Dissociation, and Abuse Characteristics in Women Survivors of Intrafamilial Child Sexual Abuse Perpetrated by a Parental-Figure

The consequences of intrafamilial child sexual abuse (CSA) often evolve beyond the termination of abuse and pervade into adulthood, posing complex and enduring consequences for survivors (Courtois, 1999; Briere, 1992; Herman, 1981, 1991; van der Kolk & Kadish, 1987; Chu & Dill, 1990). The concepts of attachment, shame, and dissociation- in the context of childhood sexual abuse-are significant areas of study when working with adult survivors. The present study included 49 women with a history of childhood sexual abuse perpetrated by a parental-figure. The purpose of the study was to identify the relationships among adult attachment styles, shame, dissociation, and specific CSA characteristics (age at onset, relationship to the perpetrator, duration of abuse, experience of other types of abuse). Participants voluntarily and anonymously participated in completing 4 self-administered measures on demographics, adult attachment styles, levels of shame, and levels of dissociation. Treatment variables were also investigated including type of treatment currently being received at the agency, frequency of this treatment, and overall duration of treatment to assess their possible relationships to adult attachment styles, levels of shame and dissociation, and CSA characteristics. The major findings suggest that the experience of earlier age at onset, having a father as the perpetrator, longer duration of abuse, and experience of other types of abuse lends to a greater likelihood towards fearful attachment style; adult survivors with fearful attachment styles are more likely to have high level of shame; and adult survivors with high level of shame have high level of dissociation. Additional findings of importance are that the experience of earlier age at onset, having a father as the perpetrator, longer duration of abuse, and experience of other types of abuse lends to a greater likelihood towards both high levels of shame and high levels of dissociation which in turn were related to more frequent treatment. The finding also suggests that adult survivors with a high level of dissociation stay longer in treatment

Environment of Er in a-Si:H: co-sputtering versus ion implantation

We report a comparative Extended X-Ray Fine Structure (EXAFS) study of Er in a-Si:H prepared by Er implantation in a-Si:H and by co-sputtering undergoing the same cumulative annealing processes. It was found that the Er environment in as-implanted samples is formed by Si atoms, which are replaced by oxygen under annealing. In the co-sputtered samples, the initial low coordination oxygen environment evolves under thermal treatment to an Er2O3 -like neighborhood.756759Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Spin-orbit induced mixed-spin ground state in RRNiO3_3 perovskites probed by XAS: new insight into the metal to insulator transition

We report on a Ni L$_{2,3}$ edges x-ray absorption spectroscopy (XAS) study in $R$NiO$_3$ perovskites. These compounds exhibit a metal to insulator ($MI$) transition as temperature decreases. The L$_{3}$ edge presents a clear splitting in the insulating state, associated to a less hybridized ground state. Using charge transfer multiplet calculations, we establish the importance of the crystal field and 3d spin-orbit coupling to create a mixed-spin ground state. We explain the $MI$ transition in $R$NiO$_3$ perovskites in terms of modifications in the Ni$^{3+}$ crystal field splitting that induces a spin transition from an essentially low-spin (LS) to a mixed-spin state.Comment: 4 pages, 4 figures, accepted as PRB - Rapid Comm. Dez. 200

Differences in decision-making behavior between elite and amateur team-handball players in a near-game test situation

Athletic features distinguishing experts from non-experts in team sports are relevant for performance analyses, talent identification and successful training. In this respect, perceptual-cognitive factors like decision making have been proposed to be important predictor of talent but, however, assessing decision making in team sports remains a challenging endeavor. In particular, it is now known that decisions expressed by verbal reports or micro-movements in the laboratory differ from those actually made in on-field situations in play. To address this point, our study compared elite and amateur players' decision-making behavior in a near-game test environment including sport-specific sensorimotor responses. Team-handball players (N = 44) were asked to respond as quickly as possible to representative, temporally occluded attack sequences in a team-handball specific defense environment on a contact plate system. Specifically, participants had to choose and perform the most appropriate out of four prespecified, defense response actions. The frequency of responses and decision time were used as dependent variables representing decision-making behavior. We found that elite players responded significantly more often with offensive responses (p < 0.05, odds ratios: 2.76-3.00) in left-handed attack sequences. Decision time decreased with increasing visual information, but no expertise effect was found. We suppose that expertise-related knowledge and processing of kinematic information led to distinct decision-making behavior between elite and amateur players, evoked in a domain-specific and near-game test setting. Results also indicate that the quality of a decision might be of higher relevance than the required time to decide. Findings illustrate application opportunities in the context of performance analyses and talent identification processes

Inhibition of DNA replication fork progression and mutagenic potential of 1, N6-ethenoadenine and 8-oxoguanine in human cell extracts

Comparative mutagenesis of 1,N6-ethenoadenine (εA) and 8-oxoguanine (8-oxoG), two endogenous DNA lesions that are also formed by exogenous DNA damaging agents, have been evaluated in HeLa and xeroderma pigmentosum variant (XPV) cell extracts. Two-dimensional gel electrophoresis of the duplex M13mp2SV vector containing these lesions established that there was significant inhibition of replication fork movement past εA, whereas 8-oxoG caused only minor stalling of fork progression. In extracts of HeLa cells, εA was weakly mutagenic inducing all three base substitutions in approximately equal frequency, whereas 8-oxoG was 10-fold more mutagenic inducing primarily G→T transversions. These data suggest that 8-oxoG is a miscoding lesion that presents a minimal, if any, block to DNA replication in human cells. We hypothesized that bypass of εA proceeded principally by an error-free mechanism in which the undamaged strand was used as a template, since this lesion strongly blocked fork progression. To examine this, we determined the sequence of replication products derived from templates in which a G was placed across from the εA. Consistent with our hypothesis, 93% of the progeny were derived from replication of the undamaged strand. When translesion synthesis occurred, εA→T mutations increased 3-fold in products derived from the mismatched εA: G construct compared with those derived from the εA: T construct. More efficient repair of εA in the εA: T construct may have been responsible for lower mutation frequency. Primer extension studies with purified pol η have shown that this polymerase is highly error-prone when bypassing εA. To examine if pol η is the primary mutagenic translesion polymerase in human cells, we determined the lesion bypass characteristics of extracts derived from XPV cells, which lack this polymerase. The εA: T construct induced εA→G and εA→C mutant frequencies that were approximately the same as those observed using the HeLa extracts. However, εA→T events were increased 5-fold relative to HeLa extracts. These data support a model in which pol η-mediated translesion synthesis past this adduct is error-free in the context of semiconservative replication in the presence of fidelity factors such as PCNA