Growth volatility and technical progress: a simple rent-seeking model

Recent empirical evidence demonstrates that a higher level of technical progress is associated with a lower level of growth volatility and higher expected economic growth. This paper builds a simple growth model which combines the insights of Angeletos and Kollintzas (2000) and Tse (2000, 2001, 2002) with endogenous productivity growth and rent-seeking behavior to account for these stylized facts. Our model also complements the literature that focuses on the heterogeneity of different agents. Future research directions are also discussed.volatility of economic growth, technical progress, rent-seeking, stabilization policy, institution.

Observations of loading-unloading process at Saturn distant magnetotail

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Tau-dependent microtubule disassembly initiated by prefibrillar β-amyloid

Alzheimer's Disease (AD) is defined histopathologically by extracellular β-amyloid (Aβ) fibrils plus intraneuronal tau filaments. Studies of transgenic mice and cultured cells indicate that AD is caused by a pathological cascade in which Aβ lies upstream of tau, but the steps that connect Aβ to tau have remained undefined. We demonstrate that tau confers acute hypersensitivity of microtubules to prefibrillar, extracellular Aβ in nonneuronal cells that express transfected tau and in cultured neurons that express endogenous tau. Prefibrillar Aβ42 was active at submicromolar concentrations, several-fold below those required for equivalent effects of prefibrillar Aβ40, and microtubules were insensitive to fibrillar Aβ. The active region of tau was localized to an N-terminal domain that does not bind microtubules and is not part of the region of tau that assembles into filaments. These results suggest that a seminal cell biological event in AD pathogenesis is acute, tau-dependent loss of microtubule integrity caused by exposure of neurons to readily diffusible Aβ

Presentation of SLE in UK primary care using the Clinical Practice Research Datalink

OBJECTIVES: To describe the presenting symptoms of SLE in primary care using the Clinical Practice Research Database (CPRD) and to calculate the time from symptom presentation to SLE diagnosis. METHODS: Incident cases of SLE were identified from the CPRD between 2000 and 2012. Presenting symptoms were identified from the medical records of cases in the 5 years before diagnosis and grouped using the British Isles Lupus Activity Group (BILAG) symptom domains. The time from the accumulation of one, two and three BILAG domains to SLE diagnosis was investigated, stratified by age at diagnosis (<30, 30–49 and ≥50 years). RESULTS: We identified 1426 incident cases (170 males and 1256 females) of SLE. The most frequently recorded symptoms and signs prior to diagnosis were musculoskeletal, mucocutaneous and neurological. The median time from first musculoskeletal symptom to SLE diagnosis was 26.4 months (IQR 9.3–43.6). There was a significant difference in the time to diagnosis (log rank p<0.01) when stratified by age and disease severity at baseline, with younger patients <30 years and those with severe disease having the shortest times and patients aged ≥50 years and those with mild disease having the longest (6.4 years (IQR 5.8–6.8)). CONCLUSIONS: The time from symptom onset to SLE diagnosis is long, especially in older patients. SLE should be considered in patients presenting with flaring or chronic musculoskeletal, mucocutaneous and neurological symptoms

Optimal vs naïve diversification in cryptocurrencies

This paper contributes to the literature on cryptocurrencies by examining the performance of naïve (1/N) and optimal (Markowitz) diversification in a portfolio of four popular cryptocurrencies. We employ weekly data with weekly rebalancing and show there is very little to select between naïve diversification and optimal diversification. Our results hold for different levels of risk-aversion and an alternative estimation window