Postmortem changes in the level of calcium pumping adenosine triphosphatase in rat heart sarcoplasmic reticulum

The activity of calcium pumping adenosine triphosphatase (Ca2+-ATPase) in cardiac sarcoplasmic reticulum plays a pivotal role in myocardiac contraction-relaxation. The Ca2+-ATPase activity is controlled by phosphorylation and dephosphorylation of a sarcoplasmic reticulum protein "phospholamban" in response to neurotransmitters and drugs. To clarify the role of Ca2+-ATPase in the development of cardiac rigor mortis, we examined the changes of cardiac rigidity and cardiac sarcoplasmic reticulum Ca2+-ATPase activity up to 5 h after the decapitation of rats. Fifteen minutes after decapitation, the rats showed a cardiac rigidity on left ventricles. After 30 min, rigidity was obvious over the whole heart. After 1 h, the rigidity reached a high degree which was maintained for the rest of the observation period. On the other hand, the Ca2+-ATPase activity controlled by phosphorylation and dephosphorylation of phospholamban did not change for the whole observation period (5 h). Another Ca2+-ATPase activity representing the total amount of Ca2+-ATPase in sarcoplasmic reticulum gradually decreased. The data suggest that no significant phosphorylation or dephosphorylation of phospholamban occurs for a short time, at least for 5 h, after death and that the Ca2+-ATPase tends to relax the myocardium against the development of cardiac rigor mortis.     

The morphogenesis of electrically and heat-induced dermal changes in pig skin

In order to establish pathological evidence in dermis for distinguishing between sequelae of electrical torture and those of other superficial injuries, the skin of eleven fully anaesthetized Danish Landrace pigs have been exposed to heat and electrical energy from either 50 Hz alternating current (a.c.) or direct current (d.c.) via 12 mm large contact knobs or via a pointed 0.5 mm large electrode (only 50 Hz a.c.). The lesions have been examined from 1 to 126 days after the injury. While heat lesions exposed to energy lower than 60 joule only gave minor changes, heat lesions exposed to more than 60 joule showed changes in both collagen fibres (basophilic or eosinophilic fibres without any birefringence or coarse cross-striation in polarized light, respectively) and dermal cells (granular cytoplasm). Areas exposed to 50 Hz a.c. via 0.5 mm. electrode showed basophilic collagen fibres and in a few biopsies on day 7 calcium salts on collagen fibres. Using 12 mm large electrodes the changes were minor, but basophilic and eosinophilic collagen fibres with no birefringence or with fine/coarse cross-striation respectively were seen. Even cells with 'vesicular nuclei' were seen on day 1 and 2 after the injury. The changes in the anode area showed resemblance to that of heat lesions (basophilic collagen fibres). Eosinophilic collagen fibres with fine densely spaced cross-striation in polarized light and 'vesicular nuclei' as well as collagen fibres with calcium salts were seen in the cathode lesions. It is concluded that the dermal changes in the cathode area are specific for electrical injury from day 1 to 14. However, earlier studies have demonstrated dermal changes specific for electrical injury at day 0 and the presence of calcified collagen fibres up to 2 months after injury. The dermal changes in anode lesions were non specific and could not be differentiated from those found in heat lesions. Alternating current lesions (50 Hz) were specific from day 1 to day 7, when the pointed electrode was used, but only in a few days when the energy was transferred via the 12-mm electrodes.     

The Development of Future Orientation is Associated with Faster Decline in Hopelessness during Adolescence

Hopelessness is implicated in multiple psychological disorders. Little is known, however, about the trajectory of hopelessness during adolescence or how emergent future orientation may influence its trajectory. Parallel process latent growth curve modelling tested whether (i) trajectories of future orientation and hopelessness and (ii) within-individual change in future orientation and hopelessness were related. The study was comprised of 472 adolescents [52% female, 47% Caucasian, 47% received free lunch] recruited at ages 12–13 who completed measures of future orientation and hopelessness at five annual assessments. The results indicate that a general decline in hopelessness across adolescence occurs quicker for those experiencing faster development of future orientation, when controlling for age, sex, low socio-economic status in addition to stressful life events in childhood and adolescence. Stressful childhood life events were associated with worse future orientation at baseline and negative life events experienced during adolescence were associated with both an increase in the trajectory of hopelessness as well as a decrease in the trajectory of future orientation. This study provides compelling evidence that the development of future orientation during adolescence is associated with a faster decline in hopelessness.     

Rethinking the Tunisian miracle: a party politics view

Five years on from the Tunisian revolution, Tunisia stands as the sole success story of the Arab Spring. The country since then has managed to adopt a pluralist and democratic constitution, and held three free and fair elections. Accordingly, in the eyes of several observers, Tunisia is now in the process of consolidating its new democracy. However, the reality on the ground seems much gloomier, as most recent opinion surveys suggest that there is a significant degree of dissatisfaction, not only with political parties and Parliament but also with the very institution of democracy. Nevertheless, what accounts for this change? After the collapse of the long-lasting and oppressive Ben Ali regime, how, just in five years, has Tunisians’ confidence in the democratic process changed? This article accounts for this state of affairs from a party politics view, arguing that political parties, which are the main protagonists of the consolidation process, fail to fulfill their role of acquiring legitimacy for the new regime. While party–state relations seem to be stabilized due to the inclusiveness of the constitution-making process, both inter-party relationships and the relationship between parties and society suffer from numerous flaws which, in turn, hamper the democratic consolidation process.     

Vladimir Iowa Lenin,Part 2: On Rural Proletarianization and an Alternate Food Future

In the second of our two-part review of Vladimir Lenin’s 1917 study of American agriculture, we extrapolate upon Alexander Chayanov’s neoliberal appropriation, Giovanni Arrighi’s treatment of partial proletarianization, the propagandistic “family farm,” agribusiness’s fluctuating territorial embeddedness, agriculture as an industry, and land and rent as commodities themselves. We finish by deploying Lenin’s alternate history as a Benjaminian détournement in the face of what now appear insurmountable obstacles. An alternate food future is not only possible, it is already underway.     

Consequences of Forced Residential Relocation: Early Impacts of Urban Renewal Strategies on Forced Relocatees’ Housing Opportunities and Socioeconomic Outcomes

Policymakers have actively pursued urban renewal and dispersal programs to deconcentrate poverty in urban neighborhoods. Relocation strategies lead to new housing opportunities and may encourage employment opportunities for relocated residents if resourceful contacts and job information become more easily available after the move. This study provides an innovative evaluation of the early impacts of involuntary relocation programs in the Netherlands on the housing careers, earnings and employment rates of forced relocatees. It establishes a quasi-experimental design by employing unique longitudinal individual-level population registry data from Statistics Netherlands: forced relocatees are tracked and matched to a control group consisting of similar residents that were not forced to move. A difference-in-difference design shows that forced relocatees are living in less deprived neighborhoods after the move. However, we find no conclusive evidence that this upgrade in housing leads to more socioeconomic opportunities for the forced relocatees.     

Reciprocal Relationships between Teacher Ratings of Internalizing and Externalizing Behaviors in Adolescents with Different Levels of Cognitive Abilities

Are internalizing and externalizing behavior problems interrelated via mutually reinforcing relationships (with each behavior leading to increases over time in levels of the other behavior) or mutually suppressing relationships (with each behavior leading to decreases over time in levels of the other behavior)? Past research on the directionality of these relationships has led to ambiguous results, particularly in adolescence. Furthermore, the extent to which prior results will generalize to adolescents with low levels of cognitive abilities remains unknown. This second limit is particularly important, given that these adolescents are known to present higher levels of externalizing and internalizing behaviors than their peers with average-to-high levels of cognitive abilities, and that the mechanisms involved in the reciprocal relationships between these two types of behaviors may differ across both populations. This study examines the directionality of the longitudinal relationships between externalizing and internalizing behavior problems as rated by teachers across three measurement waves (corresponding to Grades 8–10) in matched samples of 138 adolescents (34.78?% girls) with low levels of cognitive abilities and 556 adolescents (44.88?% girls) with average-to-high levels of cognitive abilities. The results showed that the measurement structure was fully equivalent across time periods and groups of adolescents, revealing high levels of developmental stability in both types of problems, and moderately high levels of cross-sectional associations. Levels of both internalizing and externalizing behaviors were higher among adolescents with low levels of cognitive abilities relative to those with average-to-high levels of cognitive abilities. Finally, the predictive analyses revealed negative reciprocal longitudinal relationships (i.e., mutually suppressing relationships) between externalizing and internalizing problems, a result that was replicated within samples of adolescents with low, and average-to-high levels of cognitive ability.     

Cognitive Vulnerabilities to Depression for Adolescents in Single-Mother and Two-Parent Families

Although research consistently suggests that adolescents in single-mother families are at increased risk for depression, the mechanisms that explain this relationship are unclear. In a community sample of adolescents (N?=?368; ages 12–16; 50?% female; 50?% White) and their mothers (42?% single), adolescents completed measures of depressive symptoms, rumination, and depressogenic inferential style at baseline and two yearly follow-ups. Mothers reported on stressful events that occurred in the child’s life from birth until baseline. Adolescents raised by single mothers, relative to partnered mothers, experienced more childhood stressors and higher rumination levels at 1-year follow-up. Additionally, higher rumination mediated the relationship between single motherhood and greater youth depressive symptoms at the 2-year follow-up. Clinical implications and developmental considerations are discussed.