An Early Reduction in Treg Cells Correlates with Enhanced Local Inflammation in Cutaneous Leishmaniasis in CCR6-Deficient Mice

Resistance to Leishmania major infection is dependent on the development of a cell-mediated Th1 immune response in resistant C57BL/6 mice whereas Th2-prone BALB/c mice develop non-healing lesions after infection. The chemokine receptor CCR6 is shared by anti-inflammatory regulatory T cells and pro-inflammatory Th17 cells. In a recent study we showed that C57BL/6 mice deficient in CCR6 exhibited enhanced footpad swelling and impaired T helper cell migration indicated by reduced recruitment of total T helper cells into the skin after infection and a reduced delayed type hypersensitivity reaction. Based on these findings we tested whether the lack of CCR6 alters Treg or Th17 cell responses during the course of Leishmania major infection. When we analyzed T cell subsets in the lymph nodes of CCR6-deficient mice, Th17 cell numbers were not different. However, reduced numbers of Treg cells paralleled with a stronger IFNγ response. Furthermore, the early increase in IFNγ-producing cells correlated with increased local tissue inflammation at later time points. Our data indicate an important role of CCR6 for Treg cells and a redundant role for Th17 cells in a Th1 cell-driven anti-parasitic immune response against Leishmania major parasites in resistant C57BL/6 mice

Optimizing Chemical & Rheological Properties of Rejuvenated Bitumen

Bitumen has long been a material used in the construction of roadways, yet new pavement only consists of low fractions of recycled materials due to poor compatibility of aged bitumen and new materials. Thus, rejuvenators, chemical additives, have been used in an attempt to re-balance the chemical composition and restore the physical properties of aged bitumen back to its virgin state. A fundamental understanding of how one particular rejuvenator, soybean oil, revitalizes bitumen was investigated using a multi-scale approach. Fourier-transform infrared spectroscopy (FTIR) was used to determine the changes in chemical properties of pure and rejuvenated virgin and aged samples. Samples were artificially short term aged using a rolling thin film oven (RTFO) procedure or long term aged using a pressure aging vessel (PAV). Rejuvenator concentrations were tested at both 7.5% and 15%. FTIR results reveal carbonyl (IC=O), sulfoxide (IS=O), branched aliphatic (IB), and aromatic (IAr) indices decrease in RTFO and PAV samples from rejuvenation with soybean oil, suggesting that the aging process in the aged bitumen has been reversed. A linear amplitude sweep (LAS), a mechanical procedure using a dynamic shear rheometer (DSR), was employed to investigate rheological properties. LAS analysis of PAV samples manifests fatigue resistances of bitumen samples increase at every applied shear strain as a result of increasing concentration of rejuvenator. The relation of FTIR and LAS results indicates rejuvenation of aged bitumen with soybean oil reverses the aging process at a molecular level and, as a result, increases the fatigue life of the bitumen

Optimizing Chemical & Rheological Properties of Rejuvenated Bitumen

Bitumen has long been a material used in the construction of roadways, yet new pavement only consists of low fractions of recycled materials due to poor compatibility of aged bitumen and new materials. Thus, rejuvenators, chemical additives, have been used in an attempt to re-balance the chemical composition and restore the physical properties of aged bitumen back to its virgin state. A fundamental understanding of how one particular rejuvenator, soybean oil, revitalizes bitumen was investigated using a multi-scale approach. Fourier-transform infrared spectroscopy (FTIR) was used to determine the changes in chemical properties of pure and rejuvenated virgin and aged samples. Samples were artificially short term aged using a rolling thin film oven (RTFO) procedure or long term aged using a pressure aging vessel (PAV). Rejuvenator concentrations were tested at both 7.5% and 15%. FTIR results reveal carbonyl (IC=O), sulfoxide (IS=O), branched aliphatic (IB), and aromatic (IAr) indices decrease in RTFO and PAV samples from rejuvenation with soybean oil, suggesting that the aging process in the aged bitumen has been reversed. A linear amplitude sweep (LAS), a mechanical procedure using a dynamic shear rheometer (DSR), was employed to investigate rheological properties. LAS analysis of PAV samples manifests fatigue resistances of bitumen samples increase at every applied shear strain as a result of increasing concentration of rejuvenator. The relation of FTIR and LAS results indicates rejuvenation of aged bitumen with soybean oil reverses the aging process at a molecular level and, as a result, increases the fatigue life of the bitumen

Mood-congruent free recall bias in anxiety

The present study evaluated the status of mood-congruent free recall bias in anxious individuals following incidental encoding of target words. In the first experiment, high trait anxiety individuals showed increased recall of threat-related information after an orienting task promoting lexical processing of target words. In a second experiment, both lexical and semantic orienting tasks were performed at study. In this experiment, anxious individuals displayed a mood-congruent recall bias only for target information processed at a lexical level. Theoretical and practical implications of these findings are discussed

Single-ion conducting polymer electrolyte for Li||LiNi0.6_{0.6}Mn0.2_{0.2}Co0.2_{0.2}O2_{2} batteries—impact of the anodic cutoff voltage and ambient temperature

Polymer-based electrolytes potentially enable enhanced safety and increased energy density of lithium-metal batteries employing high capacity, transition metal oxide-positive electrodes. Herein, we report the investigation of lithium-metal battery cells comprising Li[Ni$_{0.6}$Mn$_{0.2}$Co$_{0.2}$]O$_{2}$ as active material for the positive electrode and a poly(arylene ether sulfone)-based single-ion conductor as the electrolyte incorporating ethylene carbonate (EC) as selectively coordinating molecular transporter. The resulting lithium-metal battery cells provide very stable cycling for more than 300 cycles accompanied by excellent average Coulombic efficiency (99.95%) at an anodic cutoff potential of 4.2 V. To further increase the achievable energy density, the stepwise increase to 4.3 V and 4.4 V is herein investigated, highlighting that the polymer electrolyte offers comparable cycling stability, at least, as common liquid organic electrolytes. Moreover, the impact of temperature and the EC content on the rate capability is evaluated, showing that the cells with a higher EC content offer a capacity retention at 2C rate equal to 61% of the capacity recorded at 0.05 C at 60 degrees C

The effect of everyday caffeine consumption on reports of attention and memory performance in different age groups: A preliminary investigation.

Research suggests that caffeine consumption may be associated with a reduction in cognitive impairment in the elderly. This topic was investigated by examining associations between regular caffeine consumption and subjective reports of attention and memory problems across different age groups. One hundred volunteers completed a survey which recorded caffeine consumption and subjective memory (the Everyday Memory Questionnaire [EMQ]; the Subjective Memory Questionnaire [SMQ]) and attention (the Everyday Attention Questionnaire {EAQ]). The analyses showed no statistically significant correlations between daily caffeine intake and either measure of memory performance (the SMQ or EMQ). There was, however, a weak but statistically significant correlation between daily caffeine consumption and the measure of subjective attention (the EAQ), with, as might be expected, high caffeine consumption being associated with better performance. In younger and middle-aged people, there were no significant associations between daily caffeine consumption and subjective cognitive performance, but in the group aged 55 years and older high daily caffeine consumption was associated with better everyday attention and memory performance (as measured by the EAQ and SMQ). These results from the older participants suggest further investigation, possibly using objective memory tests that would also enable acute effects of caffeine to be separated from long-term effects

Further investigation of the effects of caffeine on implicit memory, allocation of memory resources, semantic memory and executive function

Background: Research has shown that the performance of semantic processing and logical reasoning tasks improves after caffeine. There is also some evidence that implicit memory and allocation of memory resources are improved by caffeine. The aims of the present study were twofold; firstly, to attempt to replicate the effects of caffeine on implicit memory and allocation of memory resources and secondly, to investigate whether the effects of caffeine on semantic memory and executive function were mediated by the speed of reading and encoding of lexical information. Methods: Participants (University students, N=56) completed a laboratory session in the morning or afternoon. Separate groups either received caffeine or a placebo. The caffeine dose was 4mg/kg and was carried out double-blind. Tasks measuring semantic processing, logical reasoning, implicit memory and allocation of memory resources were used. Results: The performance of the semantic processing and logical reasoning tasks was significantly better in the caffeine condition. These effects did not reflect the speed of encoding of the information. Previous findings on the effects of caffeine on implicit memory and allocation of memory resources were not replicated. Conclusion: The results from this study confirm the effects of caffeine on semantic processing and executive function. These effects did not reflect the speed of encoding the new information. In contrast, no reliable effects of caffeine on implicit memory and allocation of memory resources were found. These results confirm that semantic processing and logical reasoning tasks are good indicators of the beneficial effects of caffeine, whereas other aspects of memory show little effect

Effects of regular caffeine consumption on semantic memory and executive function: A secondary analysis

Background: Research has examined the acute effects of caffeine on many aspects of memory. Less is known about the effects of the level of caffeine regularly consumed or how this might interact with the acute effects of caffeine, and this was examined using semantic processing and executive function (logical reasoning) tasks. Methods: A secondary analysis of data from three recently published studies is reported. There were 177 participants (university students) in the dataset. Chronic caffeine consumption was analysed in two ways. The first split the samples into quartiles. The second method compared those who consumed less than 30mg of caffeine daily with those with higher consumption levels. After baseline testing, separate groups either received caffeine or a placebo. The caffeine dose was 4mg/kg and was carried out double-blind. Results: At baseline, there were no significant effects of regular levels of caffeine consumption. The usual positive effects of acute caffeine were observed in both the semantic processing and logical reasoning tasks. No significant interactions existed between regular caffeine intake and caffeine/placebo groups. Conclusion: The results show little effect of the regular level of caffeine consumption and no interactions between this and acute challenge conditions. In contrast, acute effects of caffeine were observed for both tasks, confirming previous findings

Caffeine, semantic processing, logical reasoning, implicit memory, recognition memory, and allocation of memory resources

Background: Research has shown that caffeine improves the performance of semantic processing and logical reasoning tasks. The present study aimed to confirm the positive effects of caffeine on these tasks and to investigate other aspects of memory, namely implicit memory, recognition memory and allocation of memory resources. Methods: Participants (University students, N=48) completed two laboratory sessions on consecutive days. Separate groups either received caffeine or a placebo on each day or had a different condition on each day. The caffeine dose was 4mg/kg and was carried out double-blind. On day one, the participants carried out memory tests investigating semantic processing, logical reasoning, immediate recall and recognition, implicit memory and allocation of memory resources. On day two, delayed recall and recognition were tested, and a word fragmentation completion task was carried out. Results: The performance of the semantic processing and logical reasoning tasks was significantly better in the caffeine condition, as were implicit memory and word fragmentation completion. Caffeine also led to resources being directed away from lowpriority task components. Caffeine had no significant effect on immediate recall or recognition. On day two, delayed recall and recognition were not influenced by caffeine. Conclusion: The results from this study confirm the effects of caffeine on semantic processing and executive function. Recall and recognition were not influenced by caffeine, but there were new effects on the implicit memory and allocation of memory resources tasks. These results extend our knowledge of caffeine and memory and show that semantic processing and logical reasoning tasks can be used as positive controls in future research on this topic