Breakdown of the mean-field approximation in a wealth distribution model

One of the key socioeconomic phenomena to explain is the distribution of wealth. Bouchaud and M\'ezard have proposed an interesting model of economy [Bouchaud and M\'ezard (2000)] based on trade and investments of agents. In the mean-field approximation, the model produces a stationary wealth distribution with a power-law tail. In this paper we examine characteristic time scales of the model and show that for any finite number of agents, the validity of the mean-field result is time-limited and the model in fact has no stationary wealth distribution. Further analysis suggests that for heterogeneous agents, the limitations are even stronger. We conclude with general implications of the presented results.Comment: 11 pages, 3 figure

Financial development and economic growth : long-run equilibrium and transitional dynamics

We analyze the impact of financial development on economic growth. Differently from previous studies that focus mainly on balanced growth path outcomes, we also analyze the transitional dynamics of our model economy by using a finance-extended Uzawa-Lucas framework where financial intermediation affects both human and physical capital accumulation. We show that, under certain rather general conditions, economic growth may turn out to be non-monotonically related to financial development (as suggested by the most recent empirical evidence) and that too much finance may be detrimental to growth. We also show that the degree of financial development may affect the speed of convergence, which suggests that finance may play a crucial role in determining the length of the recovery process associated with exogenous shocks. Moreover, in a special case of the model, we observe that, under a realistic set of parameters, social welfare decreases with financial development, meaning that even when finance positively affects economic growth the short term costs associated with financial activities more than compensate their long run benefits

Entrepreneurs, Chance, and the Deterministic Concentration of Wealth

In many economies, wealth is strikingly concentrated. Entrepreneurs–individuals with ownership in for-profit enterprises–comprise a large portion of the wealthiest individuals, and their behavior may help explain patterns in the national distribution of wealth. Entrepreneurs are less diversified and more heavily invested in their own companies than is commonly assumed in economic models. We present an intentionally simplified individual-based model of wealth generation among entrepreneurs to assess the role of chance and determinism in the distribution of wealth. We demonstrate that chance alone, combined with the deterministic effects of compounding returns, can lead to unlimited concentration of wealth, such that the percentage of all wealth owned by a few entrepreneurs eventually approaches 100%. Specifically, concentration of wealth results when the rate of return on investment varies by entrepreneur and by time. This result is robust to inclusion of realities such as differing skill among entrepreneurs. The most likely overall growth rate of the economy decreases as businesses become less diverse, suggesting that high concentrations of wealth may adversely affect a country's economic growth. We show that a tax on large inherited fortunes, applied to a small portion of the most fortunate in the population, can efficiently arrest the concentration of wealth at intermediate levels

Looking at NB-IoT over LEO Satellite Systems: Design and Evaluation of a Service-Oriented Solution

The adoption of the NB-IoT technology in satellite communications intends to boost Internet of Things services beyond the boundaries imposed by the current terrestrial infrastructures. Apart from link-level studies in the scientific literature and preliminary 3GPP technical reports, the overall debate is still open. To provide a further step forward in this direction, the work presented herein pursues a novel service-oriented methodology to design an effective solution, meticulously stitched around application requirements and technological constraints. To this end, it conducts link-level and system-level investigations to tune physical transmissions, satellite constellation, and protocol architecture, while ensuring the expected system behavior. To offer a real smart agriculture service operating in Europe, the resulting solution exploits 24 Low Earth Orbit satellites, grouped into 8 different orbits, moving at an altitude of 500 km. The configured protocol stack supports the transmission of tens of bytes generated at the application layer, by also counteracting the issues introduced by the satellite link. Since each satellite has the whole protocol stack on-board, terminals can transmit data without the need for the feeder link. This ensures communication latencies ranging from 16 minutes to 75 minutes, depending on the served number of terminals and the physical transmission settings. Moreover, the usage of the Early Data Transmission scheme reduces communication latencies up to 40%. These results pave the way towards the deployment of an effective proof-of-concept, which drastically reduces the time-to-market imposed by the current state of the art

Systematic vs. on-demand early palliative care in gastric cancer patients: a randomized clinical trial assessing patient and healthcare service outcomes

Purpose: Early palliative care (EPC) has shown a positive impact on quality of life (QoL), quality of care, and healthcare costs. We evaluated such effects in patients with advanced gastric cancer. Methods: In this prospective, multicenter study, 186 advanced gastric cancer patients were randomized 1:1 to receive standard cancer care (SCC) plus on-demand EPC (standard arm) or SCC plus systematic EPC (interventional arm). Primary outcome was a change in QoL between randomization (T0) and T1 (12 weeks after T0) in the Trial Outcome Index (TOI) scores evaluated through the Functional Assessment of Cancer Therapy-Gastric questionnaire. Secondary outcomes were patient mood, overall survival, and family satisfaction with healthcare and care aggressiveness. Results: The mean change in TOI scores from T0 to T1 was − 1.30 (standard deviation (SD) 20.01) for standard arm patients and 1.65 (SD 22.38) for the interventional group, with a difference of 2.95 (95% CI − 4.43 to 10.32) (p = 0.430). The change in mean Gastric Cancer Subscale values for the standard arm was 0.91 (SD 14.14) and 3.19 (SD 15.25) for the interventional group, with a difference of 2.29 (95% CI − 2.80 to 7.38) (p = 0.375). Forty-three percent of patients in the standard arm received EPC. Conclusions: Our results indicated a slight, albeit not significant, benefit from EPC. Findings on EPC studies may be underestimated in the event of suboptimally managed issues: type of intervention, shared decision-making process between oncologists and PC physicians, risk of standard arm contamination, study duration, timeliness of assessment of primary outcomes, timeliness of cohort inception, and recruitment of patients with a significant symptom burden. Clinical trial registration: ClinicalTrials.gov (NCT01996540)

Systematic versus on-demand early palliative care: A randomised clinical trial assessing quality of care and treatment aggressiveness near the end of life

Aim Early palliative care (EPC) in oncology has shown sparse evidence of a positive impact on patient outcomes, quality of care outcomes and costs. Patients and methods Data for this secondary analysis were taken from a trial of 207 outpatients with metastatic pancreatic cancer randomly assigned to receive standard cancer care plus on-demand EPC (standard arm) or standard cancer care plus systematic EPC (interventional arm). After 20 months\u2019 follow-up, 149 (80%) had died. Outcome measures were frequency, type and timing of chemotherapy administration, use of resources, place of death and overall survival. Results Some indices of end-of-life (EoL) aggressiveness had a favourable impact from systematic EPC. Interventional arm patients showed higher use of hospice services: a significantly longer median and mean period of hospice care (P = 0.025 for both indexes) and a significantly higher median and mean number of hospice admissions (both P < 0.010). In the experimental arm, chemotherapy was performed in the last 30 days of life in a significantly inferior rate with respect to control arm: 18.7% versus 27.8% (adjusted P = 0.036). Other non-significant differences were seen in favour of experimental arm. Conclusions Systematic EPC showed a significant impact on some indicators of EoL treatment aggressiveness. These data, reinforced by multiple non-significant differences in most of the other items, suggest that quality of care is improved by this approach. This study is registered on ClinicalTrials.gov (NCT01996540)

Analysis of gene expression profiles in HeLa cells in response to overexpression or siRNA-mediated depletion of NASP

<p>Abstract</p> <p>Background</p> <p>NASP (Nuclear Autoantigenic Sperm Protein) is a linker histone chaperone required for normal cell division. Changes in NASP expression significantly affect cell growth and development; loss of gene function results in embryonic lethality. However, the mechanism by which NASP exerts its effects in the cell cycle is not understood. To understand the pathways and networks that may involve NASP function, we evaluated gene expression in HeLa cells in which NASP was either overexpressed or depleted by siRNA.</p> <p>Methods</p> <p>Total RNA from HeLa cells overexpressing NASP or depleted of NASP by siRNA treatment was converted to cRNA with incorporation of Cy5-CTP (experimental samples), or Cy3-CTP (control samples). The labeled cRNA samples were hybridized to whole human genome microarrays (Agilent Technologies, Wilmington, Delaware, USA). Various gene expression analysis techniques were employed: Significance Analysis of Microarrays (SAM), Expression Analysis Systematic Explorer (EASE), and Ingenuity Pathways Analysis (IPA).</p> <p>Results</p> <p>From approximately 36 thousand genes present in a total human genome microarray, we identified a set of 47 up-regulated and 7 down-regulated genes as a result of NASP overexpression. Similarly we identified a set of 56 up-regulated and 71 down-regulated genes as a result of NASP siRNA treatment. Gene ontology, molecular network and canonical pathway analysis of NASP overexpression demonstrated that the most significant changes were in proteins participating in organismal injury, immune response, and cellular growth and cancer pathways (major "hubs": TNF, FOS, EGR1, NFκB, IRF7, STAT1, IL6). Depletion of NASP elicited the changed expression of proteins involved in DNA replication, repair and development, followed by reproductive system disease, and cancer and cell cycle pathways (major "hubs": E2F8, TP53, FGF, FSH, FST, hCG, NFκB, TRAF6).</p> <p>Conclusion</p> <p>This study has demonstrated that NASP belongs to a network of genes and gene functions that are critical for cell survival. We have confirmed the previously reported interactions between NASP and HSP90, HSP70, histone H1, histone H3, and TRAF6. Overexpression and depletion of NASP identified overlapping networks that included TNF as a core protein, confirming that both high and low levels of NASP are detrimental to cell cycle progression. Networks with cancer-related functions had the highest significance, however reproductive networks containing follistatin and FSH were also significantly affected, which confirmed NASP's important role in reproductive tissues. This study revealed that, despite some overlap, each response was associated with a unique gene signature and placed NASP in important cell regulatory networks.</p