Effects of species turnover on reserve site selection in a fragmented landscape

Changes in species composition is an important process in many ecosystems but rarely considered in systematic reserve site selection. To test the influence of temporal variability in species composition on the establishment of a reserve network, we compared network configurations based on species data of small mammals and frogs sampled during two consecutive years in a fragmented Atlantic Forest landscape (SE Brazil). Site selection with simulated annealing was carried out with the datasets of each single year and after merging the datasets of both years. Site selection resulted in remarkably divergent network configurations. Differences are reflected in both the identity of the selected fragments and in the amount of flexibility and irreplaceability in network configuration. Networks selected when data for both years were merged did not include all sites that were irreplaceable in one of the 2 years. Results of species number estimation revealed that significant changes in the composition of the species community occurred. Hence, temporal variability of community composition should be routinely tested and considered in systematic reserve site selection in dynamic systems.

Voluntary action and causality in temporal binding

Previous studies have documented temporal attraction in perceived times of actions and their effects. While some authors argue that voluntary action is a necessary condition for this phenomenon, others claim that the causal relationship between action and effect is the crucial ingredient. In the present study, we investigate voluntary action and causality as the necessary and sufficient conditions for temporal binding. We used a variation of the launching effect proposed by Michotte, in which participants controlled the launch stimulus in some blocks. Volunteers reported causality ratings and estimated the interval between the two events. Our results show dissociations between causality ratings and temporal estimation. While causality ratings are not affected by voluntary action, temporal bindings were only found in the presence of both voluntary action and high causality. Our results indicate that voluntary action and causality are both necessary for the emergence of temporal binding.

CCP1/Nna1 functions in protein turnover in mouse brain: Implications for cell death in Purkinje cell degeneration mice

Purkinje cell degeneration (pcd) mice have a mutation within the gene encoding cytosolic carboxypeptidase 1 (CCP1/Nna1), which has homology to metallocarboxypeptidases. To assess the function of CCP1/Nna1, quantitative proteomics and peptidomics approaches were used to compare proteins and peptides in mutant and wild-type mice. Hundreds of peptides derived from cytosolic and mitochondrial proteins are greatly elevated in pcd mouse hypothalamus, amygdala, cortex, prefrontal cortex, and striatum. However, the major proteins detected on 2-D gel electrophoresis were present in mutant and wild-type mouse cortex and hypothalamus at comparable levels, and proteasome activity is normal in these brain regions of pcd mice, suggesting that the increase in cellular peptide levels in the pcd mice is due to reduced degradation of the peptides downstream of the proteasome. Both nondegenerating and degenerating regions of pcd mouse brain, but not wild-type mouse brain, show elevated autophagy, which can be triggered by a decrease in amino acid levels. Taken together with previous studies on CCP1/Nna1, these data suggest that CCP1/Nna1 plays a role in protein turnover by cleaving proteasome-generated peptides into amino acids and that decreased peptide turnover in the pcd mice leads to cell death.-Berezniuk, I., Sironi, J., Callaway, M. B., Castro, L. M., Hirata, I. Y., Ferro, E. S., Fricker, L. D. CCP1/Nna1 functions in protein turnover in mouse brain: Implications for cell death in Purkinje cell degeneration mice. FASEB J. 24, 1813-1823 (2010). www.fasebj.org

Effects of voluntary running on spatial memory and mature brain-derived neurotrophic factor expression in mice hippocampus after status epilepticus

Voluntary physical activity improves memory and learning ability in rodents, whereas status epilepticus has been associated with memory impairment. Physical activity and seizures have been associated with enhanced hippocampal expression of BDNF, indicating that this protein may have a dual role in epilepsy. The influence of voluntary physical activity on memory and BDNF expression has been poorly studied in experimental models of epilepsy. In this paper, we have investigated the effect of voluntary physical activity on memory and BDNF expression in mice with pilocarpine-incluced epilepsy. Male Swiss mice were assigned to four experimental groups: pilocarpine sedentary (PS), pilocarpine runners (PRs), saline sedentary (SS) and saline runners (SRs). Two days after pilocarpine-induced status epilepticus, the affected mice (PR) and their running controls (SR) were housed with access to a running wheel for 28 days. After that, the spatial memory and the expression of the precursor and mature forms of hippocampal BDNF were assessed. PR mice performed better than PS mice in the water maze test. In addition, PR mice had a higher amount of mature BDNF (14 kDa) relative to the total BDNF (14 kDa + 28 kDa + 32 kDa forms) content when compared with PS mice. These results show that voluntary physical activity improved the spatial memory and increased the hippocampal content of mature BDNF of mice with pilocarpine-induced status epilepticus. (C) 2009 Elsevier B.V. All rights reserved.

Intention/Reception : En fallstudie av en låtskrivare/musikers avsikter kontra tio lyssnares upplevelser

Tio deltagare fick lyssna på två musikaliska verk varefter de, fritt formulerande, fick besvara frågor avseende de två verken. Upphovsmannen till verken intervjuades för att få fram intentionerna bakom verken och även bakgrunden till dem. Syftet var att, i en fallstudie, undersöka relationen mellan musikintention och musikreception. De huvudsakliga resultaten var att huruvida låtskrivaren/musikerns intentioner gick fram till åhöraren berodde på flertalet variabler. Vad gällde en låts handling var lättillgängligheten betydande. Ju mer komplex och okonventionell låt desto mindre sannolikhet att handlingen gick fram. Gällande upplevelser, känslor och associationer var låtens stämning, struktur och generella uttryck av stor vikt.

Idrottsämnet och ämnessamverkan : Idrottslärares attityder och förutsättningar till ämnessamverkan

Our interest about interdisciplinary teaching has grown during our time at Högskolan Dalarna and especially during the subject physical education. It became clear that people learn in different ways. The theoretical education in school benefits the visual and auditory strong learners but the kinesthetic strong learners find it more difficult to absorb the information. We argue that integrating subjects is a good way to mix theory and practice and thus gives more students an opportunity to learn the content of the subject. The intention of this examination paper is to investigate the relationship between the attitudes of the teachers regarding interdisciplinary teaching, the practical restrains, possibilities and the presence of interdisciplinary teaching at three different schools. Semi-structured interviews with six physical educators and three principals have been performed. An ad-hoc method has been used, with categorizing (teachers), and narrative (principals). Teachers and principal’s definitions of, the pros and cons for, and the actual presence of interdisciplinary teaching have been investigated. The main results of our studies are: 1) That teachers and principals define interdisciplinary teaching as thematic work. 2) Teachers experience lack of time for collective planning due to others duties. 3) Teachers and principals understanding of physical education makes it difficult to integrate physical education with other subjects. Some of the conclusions from this study are that interdisciplinary teaching must be voluntary. Conditions to practice interdisciplinary teaching must be sufficient, e.g regarding collective planning time. An increased presence of interdisciplinary teaching that includes physical education requires a new understanding of physical education.

Informal sanctions and conditional cooperation: : A natural experiment on voluntary contributions to a public good.

In a natural experiment, this paper studies the impact of an informal sanctioning mechanism on individuals’ voluntary contribution to a public good. Cross-country skiers’ actual cash contributions in two ski resorts, one with and one without an informal sanctioning system, are used. I find the contributing share to be higher in the informal sanctioning system (79 percent) than in the non-sanctioning system (36 percent). Previous studies in one-shot public good situations have found an increasing conditional contribution (CC) function, i.e. the relationship between expected average contributions of other group members and the individual’s own contribution. In contrast, the present results suggest that the CC-function in the non-sanctioning system is non-increasing at high perceived levels of others’ contribution. This relationship deserves further testing in lab.

Mechanism of Muscle Vibrations During Stimulated and Voluntary Isometric Contractions of Mammalian Skeletal Muscle

When a muscle contracts it produces vibrations. The origin of these vibrations is not known in detail. The purpose of this study was to determine the mechanism associated with muscle vibrations. Mechanisms which have been proposed in the literature were described as theories (cross-bridge cycling, vibrating string and unfused motor unit theories). Specific predictions were derived from each theory, and tested in three conceptually different studies. In the first study, the influence of recruitment strategies of motor units (MUs) on the vibromyographic (VMG) signal was studied in the in-situ cat soleus using electrical stimulation of the soleus nerve. VMG signals increased with increasing recruitment and decreased with increasing firing rates of MUs. Similar results were obtained for the human rectus femoris (RF) muscle using percutaneous electrical stimulation of the femoral nerve. The influence of MU activation on muscle vibrations was studied in RF by analyzing VMG signals at different percentages (0-100%) of the maximal voluntary contraction (MVC). In our second study, we tested the effects of changing the material properties of the in-situ cat soleus (through muscle length changes) on the VMG signal. The magnitude of the VMG signal was higher for intermediate muscle lengths compared to the longest and the shortest muscle lengths. The decreased magnitude of the VMG signal at the longest and at the shortest muscle lengths was associated with increased passive stiffness and with decreased force transients during unfused contractions, respectively. In the third study, the effect of fatigue on muscle vibrations was studied in human RF and vastus lateralis (VL) musc1es during isometric voluntary contractions at a leveI of 70% MVC. A decrease in the VMG signal magnitude was observed in RF (presumably due to derecruitment of MUs) and an increase in VL (probably related to the enhancement of physiological tremor, which may have occurred predorninantly in a mediolateral direction) with fatigue. The unfused MU theory, which is based on the idea that force transients produced by MUs during unfused tetanic contraction is the mechanism for muscle vibrations, was supported by the results obtained in the above three studies.

Investimento em educação e "turnover" critério para otimização do investimento em educação nas empresas

Trata da questão da elaboração de políticas de educação nas empresas, e seus impactos com relação ao "turnover". Aborda como políticas de educação distintas atraem indivíduos com características diferentes. Analisa uma pesquisa realizada na Grande São Paulo", apontando critérios para otimizar o retorno do investimento em educação nas empresas.

Um modelo alternativo para o estudo do turnover

Trata do problema do Turnover nas empresas. Apresenta e discute os principais modelos que estudam e, variáveis relevantes que influenciam no turno ver e na sua relação como desempenho dos indivíduos. Critica os modelos e apresenta um modelo alternativo que é testado através de uma pesquisa. Os dados não confirmaram o modelo proposto em sua totalidade

Managerial turnover and leverage under a takeover threat

How do shareholders perceive managers who lever up under a takeover threat? Increasing leverage conveys good news if it reflects management's ability to enhance value. It conveys bad news, though, if inefficient managers are more pressured to lever up. This paper demonstrates that negative (positive) updating prevails when takeover costs are small (large). Managers who leve r up to end a takeover threat thus may commit to an increase in the firm's value and yet increase their chances of being replaced by their shareholders. The model predicts that intraindustry leverage is less dispersed when takeover costs are low.

Political budget cycles in a fiscal federation : the effect of partisan voluntary transfers

This article first presents an econometric study suggesting that intergovernmental transfers to Brazilian municipalities are strongly partisan motivated. In light of that stylized fact, it develops an extension to Rogoff (1990)’s model to analyze the effect of partisan motivated transfers into sub-national electoral and fiscal equilibria. The main finding is that important partisan transfers may undo the positive selection aspect of political budget cycles. Indeed, partisan transfers may, on one hand, eliminate the political budget cycle, solving a moral hazard problem, but, on the other hand, they may retain an incompetent incumbent in office, bringing about an adverse selection problem.