Prominent microglial activation in cortical white matter is selectively associated with cortical atrophy in primary progressive aphasia.

AIMS: Primary progressive aphasia (PPA) is a clinical syndrome characterized by selective language impairments associated with focal cortical atrophy favouring the language dominant hemisphere. PPA is associated with Alzheimer's disease (AD), frontotemporal lobar degeneration (FTLD) and significant accumulation of activated microglia. Activated microglia can initiate an inflammatory cascade that may contribute to neurodegeneration, but their quantitative distribution in cortical white matter and their relationship with cortical atrophy remain unknown. We investigated white matter activated microglia and their association with grey matter atrophy in 10 PPA cases with either AD or FTLD-TDP pathology. METHODS: Activated microglia were quantified with optical density measures of HLA-DR immunoreactivity in two regions with peak cortical atrophy, and one nonatrophied region within the language dominant hemisphere of each PPA case. Nonatrophied contralateral homologues of the language dominant regions were examined for hemispheric asymmetry. RESULTS: Qualitatively, greater densities of activated microglia were observed in cortical white matter when compared to grey matter. Quantitative analyses revealed significantly greater densities of activated microglia in the white matter of atrophied regions compared to nonatrophied regions in the language dominant hemisphere (P < 0.05). Atrophied regions of the language dominant hemisphere also showed significantly more activated microglia compared to contralateral homologues (P < 0.05). CONCLUSIONS: White matter activated microglia accumulate more in atrophied regions in the language dominant hemisphere of PPA. While microglial activation may constitute a response to neurodegenerative processes in white matter, the resultant inflammatory processes may also exacerbate disease progression and contribute to cortical atrophy.

Overcoming resolution limits with quantum sensing.

The field of quantum sensing explores the use of quantum phenomena to measure a broad range of physical quantities, of both static and time-dependent types. While for static signals the main figure of merit is sensitivity, for time dependent signals it is spectral resolution, i.e. the ability to resolve two different frequencies. Here we study this problem, and develop new superresolution methods that rely on quantum features. We first formulate a general criterion for superresolution in quantum problems. Inspired by this, we show that quantum detectors can resolve two frequencies from incoherent segments of the signal, irrespective of their separation, in contrast to what is known about classical detection schemes. The main idea behind these methods is to overcome the vanishing distinguishability in resolution problems by nullifying the projection noise.

The effect of insoles on the incidence and severity of low back pain among workers whose job involves long-distance walking.

The prevalence and incidence of low back pain in general society is high. Workers whose job involves walking long distances have an even higher tendency to suffer from low back pain. A positive effect of insoles in reducing low back pain was found in professional sports players. This was not examined on people whose job involves walking long distances. In this double blind prospective study we examined the effectiveness of insoles constructed in a computerized method to placebo insoles in 58 employees whose work entailed extensive walking and who suffered from low back pain. The evaluation was performed by the MILLION questionnaire, which is considered as a valid questionnaire for evaluation of low back pain. We calculated the differences of the pain intensity before and after the intervention, in the employees using the insoles manufactured by computer in comparison to the users of the placebo insoles. In each group, the analysis was performed in comparison to the baseline. A total of 81% of the employees preferred the real insoles as effective and comfortable in comparison to 19% of the users of the placebo insoles (P<0.05). The results of this study indicate a substantial improvement in the low back pain after the use of the true insoles. The average pain intensity according to the MILLION questionnaire before the use of the insoles was 5.46. However, after the use of the real insoles and the placebo insoles, the average pain intensity decreased to 3.96 and 5.11, respectively. The difference of the average pain intensity at the start of the study and after the use of the real insoles was significant: -1.49 (P=0.0001), whereas this difference after the use of the placebo insoles was not significant: -0.31 (P=0.1189). The reported severity of pain also decreased significantly: a level 5 pain and above was reported by 77% of the subjects at the start of the study. After the use of the real insoles only 37.9% of the subjects reported a similar degree of pain severity, and 50% of the subjects did so after the use of the placebo insoles (P< 0.05). We did not find a link between low back pain and other variables such as gender, age, number of offspring, work seniority, smoking, previous use of insoles and previous medication. This study demonstrates that the low back pain decreased significantly after the use of real insoles compared to placebo ones.