110 research outputs found
Economic Aspects of Climate Change Adaptation and Natural Hazard Risk Mitigation
According to Munich Re (2013), economic losses related to natural disasters have increased from an average of 200 billion over the last decade. The cost of natural disasters is accumulating rapidly and some claim that climate change is responsible. Others believe that human behaviors like population growth or land use should be blamed for these rising costs. The process of climate change has already taken place, and it is expected to continue to impact the future. As a result, people are more vulnerable today. Therefore, understanding the economic aspects of climate change and natural hazard risks should be considered as a major issue and addressed in greater detail. This dissertation aimed to explore household preferences of climate change adaptation and the economic impacts of natural hazards at both micro- and macro- levels.
The dissertation consisted of three related empirical studies based on the two main changes that will occur with climate change predicted by scientific climate models: stronger hurricanes and rising sea levels. The first chapter examined the impact of a recent hurricane on household activities. The objective was to find out whether a more intensified hurricane caused greater damages, and whether such damages had a long-lasting impact on household recovery. If the impact of natural hazards is worse than before, people should avoid putting themselves in harm\u27s way. However, evidence indicates that the population in coastal cities is still growing fast, as people tend to reside near the beaches and attractive landscapes. Concerns are thus prompted by the possible lack of perceptions for future risks caused by natural hazards. Therefore, the second chapter focused on household perceptions and preferences for adapting to sea level rise in Florida. Lastly, although a disaster strikes rich or poor nations indifferently, some small island nations are among the most vulnerable. In the third chapter, the macroeconomic implications of natural hazards in Central America and the Caribbean were investigated. A careful examination of the economic factors that can lead to smaller losses and higher abilities to cope with disasters is crucial in such countries
Global review of the H5N8 avian influenza virus subtype
Orthomyxoviruses are negative-sense, RNA viruses with segmented genomes that are highly unstable due to reassortment. The highly pathogenic avian influenza (HPAI) subtype H5N8 emerged in wild birds in China. Since its emergence, it has posed a significant threat to poultry and human health. Poultry meat is considered an inexpensive source of protein, but due to outbreaks of HPAI H5N8 from migratory birds in commercial flocks, the poultry meat industry has been facing severe financial crises. This review focuses on occasional epidemics that have damaged food security and poultry production across Europe, Eurasia, the Middle East, Africa, and America. HPAI H5N8 viral sequences have been retrieved from GISAID and analyzed. Virulent HPAI H5N8 belongs to clade 2.3.4.4b, Gs/GD lineage, and has been a threat to the poultry industry and the public in several countries since its first introduction. Continent-wide outbreaks have revealed that this virus is spreading globally. Thus, continuous sero- and viro-surveillance both in commercial and wild birds, and strict biosecurity reduces the risk of the HPAI virus appearing. Furthermore, homologous vaccination practices in commercial poultry need to be introduced to overcome the introduction of emergent strains. This review clearly indicates that HPAI H5N8 is a continuous threat to poultry and people and that further regional epidemiological studies are needed
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Reconstructing aspects of human embryogenesis with pluripotent stem cells.
Understanding human development is of fundamental biological and clinical importance. Despite its significance, mechanisms behind human embryogenesis remain largely unknown. Here, we attempt to model human early embryo development with expanded pluripotent stem cells (EPSCs) in 3-dimensions. We define a protocol that allows us to generate self-organizing cystic structures from human EPSCs that display some hallmarks of human early embryogenesis. These structures mimic polarization and cavitation characteristic of pre-implantation development leading to blastocyst morphology formation and the transition to post-implantation-like organization upon extended culture. Single-cell RNA sequencing of these structures reveals subsets of cells bearing some resemblance to epiblast, hypoblast and trophectoderm lineages. Nevertheless, significant divergences from natural blastocysts persist in some key markers, and signalling pathways point towards ways in which morphology and transcriptional-level cell identities may diverge in stem cell models of the embryo. Thus, this stem cell platform provides insights into the design of stem cell models of embryogenesis
Availability and trend of dissemination of cardiac rehabilitation in China: report from the multicenter national registration platform between 2012 and 2021
The study aimed to evaluate the current status of cardiac rehabilitation programs in China by registering and tracking patients undergoing CR programs in the database. Data were extracted from the online registry platform of the China Society of Cardiopulmonary Prevention and Rehabilitation from February 2012 to December 2021. Overall, data on 19,896 patients with cardiovascular diseases (CVDs) from 159 hospitals in 34 provinces of China were extracted. From a time point of view, the number of patients who had undergone CR and institutions that perform CR showed the first decline in 2009 and then increased until 2021. From a geographic point of view, the degree of participation varied greatly among regions, most of which were concentrated in eastern parts of China. A higher population of patients who underwent CR were male, aged less than 60 years, with low-a risk for coronary heart disease (CHD), and tended to choose the hospital-based CR program among all cases registered in the database. The top three diseases in the patients who participated in CR were CHD, hypertension, and metabolic syndrome (MS). Centers with CR were more likely to be tertiary-level hospitals. After adjusting for baseline values, there were significant differences in post-CR exercise capacity among the three groups (home-based CR group, hospital-based CR group, and hybrid CR group), which were in favor of the hybrid CR group compared with other groups. The underutilization of CR is a global issue, not just in China. Despite the number of CR programs showing an increasing trend in the past years, CR in China is still in the preliminary stage of development. Furthermore, the participation of CR in China shows wide diversity across geography, disease, age, sex, risk stratification, and hospital-level factors. These findings reinforce the importance of the implementation of effective measures to improve the participation, enrollment in, and uptake of cardiac rehabilitation
Practical Asynchronous Distributed Key Generation: Improved Efficiency, Weaker Assumption, and Standard Model
Distributed key generation (DKG) allows bootstrapping threshold cryptosystems without relying on a trusted party, nowadays enabling fully decentralized applications in blockchains and multiparty computation (MPC). While we have recently seen new advancements for asynchronous DKG (ADKG) protocols, their performance remains the bottleneck for many applications, with only one protocol being implemented (DYX+ ADKG, IEEE S&P 2022). DYX+ ADKG relies on the Decisional Composite Residuosity assumption (being expensive to instantiate) and the Decisional Diffie-Hellman assumption, incurring a high latency (more than 100s with a failure threshold of 16). Moreover, the security of DYX+ ADKG is based on the random oracle model (ROM) which takes hash function as an ideal function; assuming the existence of random oracle is a strong assumption, and up to now, we cannot find any theoretically-sound implementation. Furthermore, the ADKG protocol needs public key infrastructure (PKI) to support the trustworthiness of public keys. The strong models (ROM and PKI) further limit the applicability of DYX+ ADKG, as they would add extra and strong assumptions to underlying threshold cryptosystems. For instance, if the original threshold cryptosystem works in the standard model, then the system using DYX+ ADKG would need to use ROM and PKI.
In this paper, we design and implement a modular ADKG protocol that offers improved efficiency and stronger security guarantees. We explore a novel and much more direct reduction from ADKG to the underlying blocks, reducing the computational overhead and communication rounds of ADKG in the normal case. Our protocol works for both the low-threshold and high-threshold scenarios, being secure under the standard assumption (the well-established discrete logarithm assumption only) in the standard model (no trusted setup, ROM, or PKI)
Chicken IFI6 inhibits avian reovirus replication and affects related innate immune signaling pathways
Interferon-alpha inducible protein 6 (IFI6) is an important interferon-stimulated gene. To date, research on IFI6 has mainly focused on human malignant tumors, virus-related diseases and autoimmune diseases. Previous studies have shown that IFI6 plays an important role in antiviral, antiapoptotic and tumor-promoting cellular functions, but few studies have focused on the structure or function of avian IFI6. Avian reovirus (ARV) is an important virus that can exert immunosuppressive effects on poultry. Preliminary studies have shown that IFI6 expression is upregulated in various tissues and organs of specific-pathogen-free chickens infected with ARV, suggesting that IFI6 plays an important role in ARV infection. To analyze the function of avian IFI6, particularly in ARV infection, the chicken IFI6 gene was cloned, a bioinformatics analysis was conducted, and the roles of IFI6 in ARV replication and the innate immune response were investigated after the overexpression or knockdown of IFI6 in vitro. The results indicated that the molecular weight of the chicken IFI6 protein was approximately 11 kDa and that its structure was similar to that of the human IFI27L1 protein. A phylogenetic tree analysis of the IFI6 amino acid sequence revealed that the evolution of mammals and birds was clearly divided into two branches. The evolutionary history and homology of chickens are similar to those of other birds. Avian IFI6 localized to the cytoplasm and was abundantly expressed in the chicken lung, intestine, pancreas, liver, spleen, glandular stomach, thymus, bursa of Fabricius and trachea. Further studies demonstrated that IFI6 overexpression in DF-1 cells inhibited ARV replication and that the inhibition of IFI6 expression promoted ARV replication. After ARV infection, IFI6 modulated the expression of various innate immunity-related factors. Notably, the expression patterns of MAVS and IFI6 were similar, and the expression patterns of IRF1 and IFN-β were opposite to those of IFI6. The results of this study further advance the research on avian IFI6 and provide a theoretical basis for further research on the role of IFI6 in avian virus infection and innate immunity
Identification of a CTRP9 C-Terminal polypeptide capable of enhancing bone-derived mesenchymal stem cell cardioprotection through promoting angiogenic exosome production.
BACKGROUND: Mesenchymal stem cell therapy improves ischemic heart failure via incompletely understood mechanisms. C1q-TNFα related protein-9 (CTRP9) is a novel anti-oxidative cardiokine capable of improving the local microenvironment and cell survival by its c-terminal active globular domain (gCTRP9). The current study attempted to: 1) identify active gCTRP9 c-terminal polypeptides with stem cell protective function; 2) determine whether a lead polypeptide may enable/enhance cortical bone-derived mesenchymal stem cell (CBSC) cardioprotection against post-myocardial infarction (post-MI) remodeling; and 3) define the responsible underlying cellular/molecular mechanisms.
METHODS AND RESULTS: Utilizing I-TASSER structure prediction and 3-D active site modeling, we cloned and purified 3 gCTRP9 fragments (CTRP9-237, CTRP9-277, and CTRP9-281). Their activation of cell salvage kinase was compared against gCTRP9. Among the three fragments, CTRP9-281 (a 45 residue-containing polypeptide) exerted comparable or greater ERK1/2 activation compared to gCTRP9. Treatment with CTRP9-281 or gCTRP9 significantly increased CBSC proliferation and migration, and attenuated oxidative stress-induced CBSC apoptosis. CTRP9-281 and gCTRP9 comparably upregulated SOD2 and SOD3 expression. However, CTRP9-281, not gCTRP9, upregulated FGF2 and VEGFA expression/secretion in an ERK1/2 dependent manner. Administration of gCTRP9 or CTRP9-281 alone attenuated post-MI cardiac dysfunction and improved CBSC retention in the infarcted heart in similar fashion. However, CTRP9-281 exerted greater synergistic effect with CBSC than gCTRP9 related to pro-angiogenic, anti-fibrotic, and anti-remodeling effects. Mechanistically, CTRP9-281 significantly increased SOD2-rich and VEGFA-rich exosome production by CBSC. Exosomes from CTRP9-281 treated CBSC significantly attenuated oxidative stress-induced cardiomyocyte apoptosis in vitro. An exosome generation inhibitor attenuated CTRP9-281 enhancement of CBSC cardioprotection in vivo.
CONCLUSION: We identified a CTRP9 polypeptide that upregulates SOD2/SOD3 expression and improves CBSC survival/retention, similar to gCTRP9. Moreover, CTRP9-281 stimulates VEGFA-rich exosome production by CBSC, exerting superior pro-angiogenic, anti-fibrotic, and cardioprotective actions
Vitamin D and cause-specific vascular disease and mortality:a Mendelian randomisation study involving 99,012 Chinese and 106,911 European adults
Discrete element modeling of the machining processes of brittle materials: recent development and future prospective
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