Three Essays on Asset Pricing

The first essay examines whether risk is explained based on cash flow (CF) or discount rate (DR). Realized returns comprise (ex-ante) expected returns plus (ex-post) innovations, and consequently both expected returns and returns innovations can be broken down into components reflecting fluctuations in CF and DR. I use a present-value model to identify the CF and DR risk factors which are latent from the time series and cross sections of price-dividend ratios. This setup accommodates models where CF risk dominates, like Bansal and Yaron (2004), and models where DR risk dominates, like Campbell and Cochrane (1999). I estimate the model on portfolios, which capture several of the most common cross-sectional anomalies, and decompose the expected and unexpected returns into CF and DR components along both time-series and cross-sectional dimensions. I find that (1) the DR risk is more likely to explain the variations of expected returns, (2) the CF risk drives the variations of unexpected returns, and (3) together they account for over 80% of the cross-sectional variance of the average stock returns. The second essay develops a liability driven investment framework that incorporates downside risk penalties for not meeting liabilities. The shortfall between the asset and liabilities can be valued as an option which swaps the value of the endogenously determined optimal portfolio for the value of the liabilities. The optimal portfolio selection exhibits endogenous risk aversion and as the funding ratio deviates from the fully funded case in both directions, effective risk aversion decreases. When funding is low, the manager "swings for the fences" to take on risk, betting on the chance that liabilities can be covered. Over-funded plans also can afford to take on more risk as liabilities are already well covered and so invest aggressively in risky securities. The third essay introduces a methodology to estimate the historical time series of returns to investment in private equity. The approach is quite general, requires only an unbalanced panel of cash contributions and distributions accruing to limited partners, and is robust to sparse data. We decompose private equity returns into a component due to traded factors and a time-varying private equity premium. We find strong cyclicality in the premium component that differs according to fund type. The time-series estimates allow us to directly test theories about private equity cyclicality, and we find evidence in favor of the Kaplan and Strmberg (2009) hypothesis that capital market segmentation helps to determine the private equity premium

Estimating Private Equity Returns from Limited Partner Cash Flows

We introduce a methodology to estimate the historical time series of returns to investment in private equity. The approach is quite general, requires only an unbalanced panel of cash contributions and distributions accruing to limited partners, and is robust to sparse data. We decompose private equity returns into a component due to traded factors and a time-varying private equity premium. We find strong cyclicality in the premium component that differs according to fund type. The time-series estimates allow us to directly test theories about private equity cyclicality, and we find evidence in favor of the Kaplan and Strömberg (2009) hypothesis that capital market segmentation helps to determine the private equity premium

Estimating Private Equity Returns from Limited Partner Cash Flows

We introduce a methodology to estimate the historical time series of returns to investment in private equity. The approach is quite general, requires only an unbalanced panel of cash contributions and distributions accruing to limited partners, and is robust to sparse data. We decompose private equity returns into a component due to traded factors and a time-varying private equity premium. We find strong cyclicality in the premium component that differs according to fund type. The time-series estimates allow us to directly test theories about private equity cyclicality, and we find evidence in favor of the Kaplan and Strömberg (2009) hypothesis that capital market segmentation helps to determine the private equity premium

Gene Essentiality Profiling Reveals Gene Networks and Synthetic Lethal Interactions with Oncogenic Ras

The genetic dependencies of human cancers widely vary. Here, we catalog this heterogeneity and use it to identify functional gene interactions and genotype-dependent liabilities in cancer. By using genome-wide CRISPR-based screens, we generate a gene essentiality dataset across 14 human acute myeloid leukemia (AML) cell lines. Sets of genes with correlated patterns of essentiality across the lines reveal new gene relationships, the essential substrates of enzymes, and the molecular functions of uncharacterized proteins. Comparisons of differentially essential genes between Ras-dependent and -independent lines uncover synthetic lethal partners of oncogenic Ras. Screens in both human AML and engineered mouse pro-B cells converge on a surprisingly small number of genes in the Ras processing and MAPK pathways and pinpoint PREX1 as an AML-specific activator of MAPK signaling. Our findings suggest general strategies for defining mammalian gene networks and synthetic lethal interactions by exploiting the natural genetic and epigenetic diversity of human cancer cells. Keywords: CRISPR; AML; synthetic lethality; gene networks; RAS; genetic screensNational Institutes of Health (U.S.) (Grant CA103866)National Institutes of Health (U.S.) (Grant F31CA189437

Characterization of Vitellogenin and Vitellogenin Receptor of Conopomorpha sinensis Bradley and Their Responses to Sublethal Concentrations of Insecticide

Conopomorpha sinensis Bradley is the dominant borer pest of Litchi chinesis and Euphoria longan. Current management of C. sinensis relies upon insecticide application to adult moths. In addition to the direct mortality induced by insecticides, a sublethal dose of insecticides also affects growth, survival, and reproduction in the exposed insects. Vitellogenin (Vg) and vitellogenin receptor (VgR) are normally identified as essential reproduction-related proteins in insects. In this study, we characterized these two genes from C. sinensis, and investigated their differential responses to sublethal concentrations of insecticide. Cloned CsVg and CsVgR consist of 5391 and 5424-bp open reading frames, which encode proteins of 1796 and 1807 amino acid residues, respectively. The CsVg protein contains the typical vitellogenin, DUF1943 and VWFD domains as other reported lepidopteran Vgs. The CsVgR was characterized as a typical low density lipoprotein receptor with two highly conserved LBD and EGF precursor domains, one hydrophobic transmembrane domain, one cytoplasmic domain, and 13 putative N-glycosylation sites. We next assessed the sublethal effect of four major insecticides on egg-laying in C. sinensis. The toxicity against C. sinensis varied among the insecticides tested, with LC50 values ranging from 0.23 ppm for chlorpyrifos to 20.00 ppm for β-cypermethrin, among which emamectin benzoate (EB) showed a significant negative impact on egg-laying, survival rate, ovarian development, and mating rate of C. sinensis at LC30 doses. Further investigation showed that the transcriptional level of CsVg and CsVgR were impaired in different way at 24, 48, and 72 h after EB exposure, and this result was in agreement with the diminished egg-laying of C. sinensis in the sublethal concentration EB-treated group. A repressed transcription level of CsVgR was observed at 48 h after treatment, suggesting that EB elicits a delayed response in the abundance of CsVgR. These results established different roles of CsVg and CsVgR in response to the sublethal effect of insecticides. CsVg might be a better parameter than CsVgR for assessing the effect of sublethal insecticides on reproduction in C. sinensis

Polydatin Prevents Lipopolysaccharide (LPS)-Induced Parkinson's Disease via Regulation of the AKT/GSK3β-Nrf2/NF-κB Signaling Axis

Parkinson's disease (PD) is a common neurodegenerative disease characterized by selective loss of dopaminergic neurons in the substantia nigra (SN). Neuroinflammation induced by over-activation of microglia leads to the death of dopaminergic neurons in the pathogenesis of PD. Therefore, downregulation of microglial activation may aid in the treatment of PD. Polydatin (PLD) has been reported to pass through the blood-brain barrier and protect against motor degeneration in the SN. However, the molecular mechanisms underlying the effects of PLD in the treatment of PD remain unclear. The present study aimed to determine whether PLD protects against dopaminergic neurodegeneration by inhibiting the activation of microglia in a rat model of lipopolysaccharide (LPS)-induced PD. Our findings indicated that PLD treatment protected dopaminergic neurons and ameliorated motor dysfunction by inhibiting microglial activation and the release of pro-inflammatory mediators. Furthermore, PLD treatment significantly increased levels of p-AKT, p-GSK-3βSer9, and Nrf2, and suppressed the activation of NF-κB in the SN of rats with LPS-induced PD. To further explore the neuroprotective mechanism of PLD, we investigated the effect of PLD on activated microglial BV-2 cells. Our findings indicated that PLD inhibited the production of pro-inflammatory mediators and the activation of NF-κB pathways in LPS-induced BV-2 cells. Moreover, our results indicated that PLD enhanced levels of p-AKT, p-GSK-3βSer9, and Nrf2 in BV-2 cells. After BV-2 cells were pretreated with MK2206 (an inhibitor of AKT), NP-12 (an inhibitor of GSK-3β), or Brusatol (BT; an inhibitor of Nrf2), treatment with PLD suppressed the activation of NF-κB signaling pathways and the release of pro-inflammatory mediators in activated BV-2 cells via activation of the AKT/GSK3β-Nrf2 signaling axis. Taken together, our results are the first to demonstrate that PLD prevents dopaminergic neurodegeneration due to microglial activation via regulation of the AKT/GSK3β-Nrf2/NF-κB signaling axis

The Effects of MiFID II on Sell-Side Analysts, Buy-Side Analysts, and Firms

This paper provides early but broad empirical evidence on a major new investor protection regulation in Europe, MiFID II, which requires investment firms to unbundle investment research from other costs they charge to clients. We predict that the price separation resulting from unbundling and a hard-dollar system leads to a shrinking of the market for sell-side investment research, manifested in lower quantity of sell-side coverage that is of higher quality than before the regulation. We test our predictions in difference-in-differences matched-sample research designs with firm fixed effects. We find a decrease in the number of sell-side analysts covering European firms after MiFID II implementation, particularly for firms that are less important to the sell-side. However, research quality improves; specifically, individual analyst forecasts are more accurate and stock recommendations garner greater market reactions. In addition, sell-side analysts seem to cater more to the buy-side after MiFID II by providing industry recommendations along with stock recommendations. Importantly, we predict and find evidence that buy-side investment firms turn to more in-house research after MiFID II implementation. Equally interesting, buy-side analysts increase their participation and engagement in earnings conference calls compared to the control group. Finally, we find some evidence that stock-market liquidity decreases post-MiFID II. Our findings have implications beyond Europe, as investors are currently pressuring the U.S. Securities and Exchange Commission to adopt a similar regulation

Clinical characteristics of current COVID-19 rehabilitation outpatients in China

To understand the clinical characteristics of omicron in COVID-19 Rehabilitation Clinic after the current shift of dynamic zeroing policy, we consecutively collected the patients’ data who visited in COVID-19 Rehabilitation Clinic of a Grade-A tertiary hospital in Hangzhou, Zhejiang Province, from January 3 to January 10, 2023, analyzed related data and then compared the pneumonia between elderly and non-elderly groups. The results showed that 95.68% of the patients in COVID-19 Rehabilitation Clinic had symptoms, 70.10% had a dry cough, 12.36% had abnormal complete blood count or C-reactive protein, 19.35% had electrolyte disorder, and 2% had abnormal troponin or creatine kinase-MB. 40.45% of patients had abnormal lung CT findings, among them 86.49% of elderly patients had abnormal lung CT findings, and the utilization rate of glucocorticoids in COVID-19 Rehabilitation Clinic was only 5.98%, although people are all susceptible to getting the COVID-19 infection, the elderly are more prone to getting pneumonia, and the glucocorticoids utilization rate is relatively insufficient. It is needed to be stressed that Chinese medical staff should pay more attention to the elderly patients who are vulnerable to getting pneumonia during this period

New records and checklist of Chilocorini (Coleoptera: Coccinellidae) from China

China is one of the countries with the greatest species diversity of Chilocorini (Coleoptera: Coccinellidae), including nearly forty-five percent of the known genera and fourteen percent of all described species in this tribe. Recently, we discovered three species previously not recorded in China.In this study, three species Priscibrumus uropygialis (Mulsant, 1853), Priscibrumus disjunctus Canepari, 1997 and Brumus octosignatus (Gebler, 1830) are documented for the first time in China. Brumus octosignatus is the first member of the genus Brumus Mulsant, 1850 recorded in China. Detailed descriptions, illustrations and distributions of these three species are provided. A checklist of Chinese Chilocorini is also given

Two new species of Chilocorus Leach, 1815 from Laos (Coleoptera Coccinellidae Chilocorini)

Chilocorus Leach, 1815 the largest genus of Chilocorini, contains more than 80 species, mainly preying on Coccoidea. Many species of Chilocorus are economically important as they are widely used as biological control agents.In this study, two new species of the genus Chilocorus Leach are described from Laos: C. toulakhomianus Li & Wang, sp. n. and C. vientianicus Li & Wang, sp. n. Diagnoses and detailed descriptions of the new species are given. Each species is illustrated in detail, including genitalia. Distribution maps are presented