Miracle-dz/UniFAR-FTUs huggingface dataset:
Annualized Volatility

In this research note, we compare S&P 500 volatility figures calculated with the popular “square-root-n rule” to volatility figures derived from time-aggregated daily returns and try to reconcile the differences with popular time-series models featuring serial correlation in returns or volatilities. We show that the deviations from the square-root-n rule cannot be explained with serial correlation in returns, rather with a GARCH model. We conclude that volatility figures annualized with the square-root-n rule should not be interpreted as accurate estimates for true annual volatility. The square-root-n rule is also not suitable to standardize volatility figures for reporting purposes.
Ammonia Transport in a Temperate Grassland: I. Seasonal Transport in Relation to Soil Fertility and Crop Management

An understanding of N cycling in agricultural systems is necessary to optimize N-use efficiency and reduce N losses to the environment. The objectives of this research were to evaluate N cycling in a highly fertilized grassland in a humid temperate climate and to observe the effects of N surplus and deficit on NH3 absorption-desorption by the grass. Soil, plant, and weather measurements were taken concurrently and soil-plant-atmosphere N transport were determined. After N application, soil inorganic N decreased rapidly to background levels, due to possible microbial immobilization and plant N demand. Much of the immobilized N was remobilized during the growth period, but at insufficient rates to avoid N stress by the crop, as shown by absorption of NH3. During spring, 45% of the plant N was derived from applied fertilizer, with the balance obtained from mineralized organic N (49%) and absorption of NH3 (6%). During summer, fertilizer N accounted for 60% of accumulated grass N and NH3 absorption accounted for 11% of N not derived from fertilizer (4% of the total N), with the balance coming from mineralized organic N. Soil water content and wind speed were the dominant factors influencing the crop NH3 compensation point (CP). The daily NH3 CP was variable, but the average seasonal NH3 CP was about 14 μg m -3 .
Diversity of ectomycorrhizae on experimentally planted Douglas-fir seedlings in variable retention forestry sites on southern Vancouver Island

Studies were done on Vancouver Island of ectomycorrhizal (EM) communities at four distances (5-45 m) from isolated forest patches in three second-growth (SG) and three old-growth (OG) Douglas-fir sites subject to vari- able retention harvesting. We tested the hypothesis that retention of mature trees enhances colonization and diversity of EM fungi on seedlings planted in adjacent areas. In total 41 EM morphotypes were described, with mean diversity of 3.47 morphotypes and root colonization of 62% per seedling. Overall, root colonization declined with distance (72% at 5 m vs. 52% at 45 m), as did EM diversity (4.7 at 5 m vs. 2.9 at 45 m). For individual sites, the distance effect was significant for root colonization at four sites and for EM diversity at three to four sites. This suggests that variable re- tention is important for the recovery of ectomycorrhizal biota in harvested sites. Seedling root colonization was signifi- cantly lower in SG sites than in OG sites. Though EM diversity did not differ with stand age, OG sites had potentially more total (34) and unique (14) EM morphotypes than did SG sites (total 27, unique 7). Differences with stand age might be related to the relative abilities of EM fungi to disperse to regenerating second-growth forests. Resume : L'etude, conduite sur l'Ile de Vancouver, a porte sur des communautes ectomycorhiziennes (EM) situees a quatre distances (5-45 m) de parcelles boisees isolees, venant sur trois sites de seconde venue (SG) et trois sites suran- nes (OG) de Douglas, sujets a des coupes de retention variable (VR). Les auteurs ont verifie l'hypothese que le main- tien d'arbres matures favorise la colonisation et la diversite par les champignons EM sur les semis plantees sur les surfaces adjacentes. Les auteurs decrivent un total de 41 morphotypes EM, avec une diversite moyenne de 3,47 mor- photypes, et une colonisation moyenne de 62 % par plant. Dans l'ensemble, la colonisation racinaire diminue avec la distance (7 2%a5mv s 52 %a4 5 m), tout comme la diversite EM (4, 7a5mv s 2,9 a4 5 m). Pour ce qui est des sites individuels, la distance affecte significativement la colonisation racinaire sur quatre sites et la diversite sur trois a quatre sites. Ceci suggere que la VR est importante pour reactiver le biote mycorhizien sur les sites recoltes. La colo- nisation racinaire des plantules est significativement plus faible pour les sites SG que pour les sites OG. Bien que la diversite ne differe pas selon l'âge du peuplement, les sites OG abritent potentiellement un nombre plus grand de mor- photypes EM totaux (34) et uniques (14), que les sites SG (totaux 27, uniques 7). La difference selon l'âge du peuple- ment pourrait etre reliee aux capacites relatives des champignons EM a se disperser aux forets de seconde venue. Mots cles : sylviculture a retention variable, ecologie des ectomycorhizes, plantules de Douglas, foret surannee, foret de seconde venue. (Traduit par la Redaction) Outerbridge and Trofymow 1681
Multifactor Market Indexes

This paper combines the CRSP market index with multiple factors to create a single multifactor market index. Empirical tests of different multifactor market indexes indicate that: (1) Sharpe ratios substantially increase and GRS test statistics decrease as multifactors are incrementally added to the CRSP index; and (2) the resultant multifactor market indexes are significantly priced in cross-sectional tests of associated beta loadings with t-values exceeding 3.0 in most cases.
Replacement of Sulfur, Carbon, and Nitrogen in Tissue of Growing Broad Whitefish (Coregonus nasus) in Response to a Change in Diet Traced by δ34S, δ13C, and δ15N

We monitored the change in the isotope composition of sulfur, carbon, and nitrogen in broad whitefish (Coregonus nasus) tissues in response to a change in the isotope composition of their food. One of two batches of 2.5-yr-old fish raised in the laboratory were given a new food source with different δ34S, δ13C, and δ15N, which were monitored in muscle and liver tissue for 1 yr. A model including change due to tissue accumulation (growth) and metabolic replacement was developed. For all three isotopes, most of the change could be attributed to growth. Metabolic replacement expressed as a turnover rate was only 0.1 −0.2%∙d−1 and was similar for the three isotopes. Although liver tissue was −4.4 and −4.1‰, respectively, for δ34S and δ13C relative to muscle tissue, the response over time to the new food was the same as for muscle. We expect that the complete change in the isotope composition of fish tissue in response to a change in food could take years in slow-growing wild populations. The stable isotope co.
The role of local and regional processes in shaping dung beetle communities in tropical forest plantations in Borneo

We examine whether rain forest dung beetle species found in plantations in Sabah, northern Borneo, tend to be endemic or geographically widespread. In addition, linear regressions of abundance vs. distance from a major river in primary rain forest are calculated to see if species found in plantation forest show affinity to one specific biotope (riverine vs. interior forest) in their natural habitat. Results show that 14 of the 40 species recorded from plantations are endemic to Borneo. Only edge-specialist endemic species are found in plantation forest, with no interior-forest specialists recorded. Data suggest that endemic species that are adapted to more exposed conditions in primary rain forest, such as riverine species, can in some instances tolerate man-made habitats. Twenty-nine species ( ∠ SE 4.0) per transect are recorded from plantation transects, whereas 44.2 ( ∠ 1.7 SE) are recorded in primary rain forest. As species richness is much lower in plantations than natural forest, implying loss of biodiversity, we conclude that measures of biogeographic distinctiveness, whereby endemic species confer higher values, may be misleading unless they take into account edgeaffinity. Local- as well as regional-distributional data may therefore be needed to interpret correctly patterns of species assemblages in derived forest ecosystems.
Multi-scale patterns of habitat use in a highly mobile reef fish, the white trevally Pseudocaranx dentex, and their implications for marine reserve design

The fisheries benefits of marine reserves are hard to achieve for highly vagile fish species. An alternative is to protect essential habitats, such as spawning grounds, especially if these are stable over time. We studied the movements and habitat use patterns of white trevally Pseudo- caranx dentex (Carangidae), a commercially important species, to assist in the design of marine reserves. Diel, seasonal and inter-annual movements of trevally were studied using active acoustic tracking, passive acoustic monitoring and standard tag-release in the Faial Channel, Azores Islands. White trevally were captured at inshore and offshore reefs. Inshore trevally moved daily alongshore, using large activity spaces, while the short-term movements of offshore trevally were restricted to the reef summits. During the summer spawning season, both groups displayed frequent migrations of up to several kilometres, but inshore fish remained inshore, whereas offshore reef fish expanded their range to include visits to inshore sites. This behaviour eventually resulted in low long-term residence within the study area, especially that of inshore fish. During the spawning season, one inshore site was visited by most of the fish. However, instead of gathering in large aggregations at a single location, it appears that the trevally adopted a multiple-site visiting behaviour, which may increase mating opportunities through mixing between inshore and offshore fish that are otherwise segre- gated for most of the year. Protection of spawning biomass and sites for this species seems potentially feasible, but this would require protecting a suite of sites per island. Furthermore, because fish would not be fully protected under this scenario, we argue that such spatial management measures need to be accompanied by conventional fishing-effort control measures applied to all local populations.
Assessing stream quality using information on mesohabitat distribution and character

1. The purpose of this paper is to demonstrate: (i) how mesohabitats—medium-scale habitats which arise through the interactions of hydrological and geomorphological forces—can be used as a basis for assessing instream habitat diversity; (ii) how combining data on mesohabitat distribution with those from macroinvertebrate sampling can produce an index for assessing stream quality; and (iii) how, when nested with River Habitat Survey (RHS), mesohabitat information can provide a comprehensive assessment of stream quality. 2. A survey of a small chalk stream in southern England showed that the distribution of mesohabitats varied considerably between reaches. However, a mesohabitat quality index, derived from data on mesohabitat distribution and faunal communities, indicated that there was relatively little longitudinal variation in stream quality as defined by mesohabitat diversity and macroinvertebrate community. Heavy modification of the channel banks, as indicated by RHS, suggested significant habitat impoverishment. 3. Simulations, using different environmental conditions, suggested that the mesohabitat quality index was a potentially useful measure of stream quality. 4. The combination of mesohabitat survey and RHS provided a more comprehensive view of the stream channel and banks than either technique used alone. The study indicated that management efforts to rehabilitate impoverished reaches should be directed towards maximizing instream mesohabitat diversity and mitigating human impacts on the river margin. Copyright © 2000 John Wiley & Sons, Ltd.
Courts' Decisions, Cooperative Investments, and Incomplete Contracts

Buyers may try to motivate their sellers to make relationship-specific investments to reduce the probability that the design of the goods they procure is defective. In some countries, courts examine how much real authority the seller had in performing the work to assign liability for a design failure. I show that this courts' approach induces the sellers to under-invest and the buyers to under-specify the design of the goods. I find that this approach can also make it harder to sustain optimal relational contracting, leading to the conclusion that it cannot be justified on efficiency grounds.
Customer Controlled Firms: The Case of Stock Exchanges

In many industries there are firms whose shareholders are also customers. They have contrasting interests: they get more utility as the firm's profits increase but also if the prices of the good decreases as their private consumer surplus increases. An interesting example is in the stock-exchange industry given that the exchange shareholders are generally broker-dealers and listed companies. This paper shows that a customer-owned monopolist always achieves first-best social outcome, but in customer-controlled firms, profits are not necessarily maximized and minority shareholders are damaged. When customers have equal unit demand, less profits arise if they hold a share of the firm's capital lower than their proportion over the total number of customers. When customers have equal downward demand, the firm never maximizes profits; besides, if the share of capital of customer-owners is somewhat less than the weight of customer-owners over total customers, the firm will always price at 0. Customer-controlled stock exchanges are welfare efficient if their customers (listed firms, intermediaries, price vendors, etc) hold an amount of capital equal to their proportion over the total number of customers. They never price at the monopoly price and, thus, do not maximize profit. This finding casts some doubt on the policy of listing a stock-exchange company itself on exchanges.
Using Cultural Mindsets to Reduce Cross-National Auditor Judgment Differences

In a globalized audit environment, regulators and researchers have expressed concerns about inconsistent audit quality across nations, with a particular emphasis on Chinese audit quality. Prior research suggests Chinese audit quality may be lower than U.S. audit quality due to a weaker institutional environment (e.g., lower litigation and inspection risk) or cultural value differences (e.g., greater deference to authority). In this study, we propose that lower Chinese audit quality could also be due to Chinese auditors’ different cognitive processing styles (i.e., cultural mindsets). We find U.S. auditors are more likely to engage in an analytic mindset approach, focusing on a subset of disconfirming information, whereas Chinese auditors are more likely to take a holistic mindset approach, focusing on a balanced set of confirming and disconfirming information. As a result, Chinese auditors make less skeptical judgments compared to U.S. auditors. We then propose an intervention in which we explicitly instruct auditors to consider using both a holistic and an analytic mindset approach when evaluating evidence. We find this intervention minimizes differences between Chinese and U.S. auditors’ judgments by shifting Chinese auditors’ attention more towards disconfirming evidence, improving their professional skepticism, while not causing U.S. auditors to become less skeptical. Our study contributes to the auditing literature by identifying cultural mindset differences as a causal mechanism underlying lower professional skepticism levels among Chinese auditors compared to U.S. auditors, and providing standard setters and firms with a potential solution that can be adapted to improve Chinese auditors’ professional skepticism and reduce cross-national auditor judgment differences.
Early Sacral Neural Crest Migration in Dominant megacolon Mouse Embryos

Hirschsprung’s disease, or congenital megacolon, is the most common gastrointestinal motility disorder in newborns. The prominent feature of Hirschsprung’s disease is an abnormal dilatation of the distal colon resulting from a regional absence or reduction of enteric ganglion cells. It has been known that all intrinsic enteric ganglion cells are derived from neural crest cells, which migrate along defined pathways from the neural tube (embryonic central nervous system) to the gut during embryonic development. Recent studies on avian embryos have also indicated that neural crest cells at the sacral level contribute a significant number of enteric neurons to the hindgut, the region of the gut where aganglionosis is usually detected in Hirschsprung’s disease. In the present study, we aimed to identify anomalies in the early migration of sacral neural crest cells in the Dominant megacolon(Dom) mouse mutant, a model for Hirschsprung’s disease. A combination of whole embryo culture, in situ cell labeling and histochemical staining was used to follow the early sacral neural crest cell migration. In the wild-type embryos, when sacral neural crest cells caudal to the 24th somite were labeled at embryonic day 10.0 (E10.0), labeled cells were found in the mesenchyme on the two sides of neural tube and many of them resided in the region of dorsal root ganglia at E11.0. Some of them were also found in the region around the dorsal aorta. In embryos heterozygous and homozygous for Dom, similar distribution and migratory pattern were found, indicating that the early migration of sacral neural crest cells was not affected in the mutant. Our results hence implicated that anomalies in the early sacral crest cell migration are unlikely to be a cause of aganglionosis in the hindgut of the Dom mutant.
Employment Inequalities

This paper documents the employment disadvantage faced by the less qualified part of the labor force and examines the factors that influence the differing extent of this disadvantage across OECD countries. We argue that employment rates for quartiles of the population ranked by educational qualification provide the best measure of employment disadvantage. We show that differences in these employment rates for the most- and least-educated quartiles vary substantially within Europe, but are not on average higher than those in the USA. The least qualified suffer the greatest employment disadvantage in countries in which the overall employment rates are low and, for men, the literacy test scores for the least qualified are relatively low. A high level of imports from the South appears to be associated with greater employment disadvantage, but there is no discernible tendency for a high level of wage dispersion, low benefits, or weak employment protection legislation to be associated with greater employment disadvantage. Labor market flexibility has not been the route by which some OECD countries have managed to minimize the employment disadvantage of the least qualified.
Forced Entrepreneurs

Conventional wisdom suggests labor market distress drives workers into temporary self-employment, lowering entrepreneurial quality. Analyzing employment histories for 640,000 U.S. workers, we document graduating college during a period of high unemployment does increase entry to entrepreneurship. However, compared to voluntary entrepreneurs, firms founded by forced entrepreneurs are more likely to survive, innovate, and receive venture-backing. Explaining these results, we confirm labor shocks disproportionately impact high-earners and these same workers start more successful firms. Overall, we document untapped entrepreneurial potential across the top of the income distribution and demonstrate the role of recessions in reversing this missing entrepreneurship.
Disclosure of Purchase Obligations in Corporate Annual Filings

This paper provides an overview of purchase obligations disclosed in corporate annual filings. We discuss the details of the SEC rule that requires the disclosure of purchase obligations, describe the data collection and sample formation procedures, and show the examples of contractual obligations disclosure. Then, we present the types of purchase obligations reported by leading firms in each industry, summarize the amount of purchase obligations by industry and year, and present the portion of purchase obligations due by each period in the future. Finally, we document the strong persistence over time in the amount of a firm’s purchase obligations, and discuss the differences between purchase obligations and on-balance-sheet assets.
Changes in the additive variance of a fitness-related trait with inbreeding in Tribolium castaneum

Summary In Tribolium castaneum, a fitness-related trait was defined as the total weight loss (TWL) of a vial after 21 days, due to the activity of a single pair of parents. TWL showed considerable inbreeding depression and strong heterosis. A significant increase in the heritability of TWL was observed with inbreeding. The results are compatible with the genetic variation of TWL in the base population being generated by segregation of a number of recessive alleles at low frequencies. Resumen Cambio de la varianza aditiva de un componente principal de la eficacia biologica en Tribolium castenum con consanguinidad Elcaracter “merma” (TWL) se define en Tribolium castaneum como la perdida de peso que experimenta un pocillo de cristal que contiene medio alimenticioyuna pareja de Padre, debida a la actividad de esa pareja durante 21 dias. Es, por tanto, un importante componente de la eficacia biologica. El caracter mostro considerable depresion por consanguinidad, fuerte heterosis en cruzamientosy, ademas, un significativo incremento de su heredabilidad con el del coeficiente de consanguinidad. Estos resultados son compatibles con que la variacion genetica del caracter en la poblacion base se debiera a la scgregacion de alelos recesivos con bajas frecuencias iniciales. Zusammenfassung Anderung der additiv-genetischen Varianz eines Fitness-Merkmals bei Inzucht von Tnboleum castaneum Das Fitness Merkmal wurde als Gewichtsverlust (TWL) eines Zuchtgefases mit Elternpaar und ihren Nachkommen in 21 Tagen definiert. TWL zeigte betrachtliche Inzuchtdepression und Heterosis. Durch Inzucht ergab sich eine signifikante Steigerung der additiv-genetischen Varianz. Die Ergebnisse machen die Annahme wahrscheinlich, das in der Ausgangsgeneration die genetische Variabilitat von TWL durch Spaltung rezessiver Allele geringer Haufigkeit verursacht wurde.
Open Robotics

With millions of home and service robots already on the market, and millions more on the way, robotics is poised to be the next transformative technology. As with personal computers, personal robots are more likely to thrive if they are sufficiently open to third-party contributions of software and hardware. No less than with telephony, cable, computing, and the Internet, an open robotics could foster innovation, spur consumer adoption, and create secondary markets. But open robots also present the potential for inestimable legal liability, which may lead entrepreneurs and investors to abandon open robots in favor of products with more limited functionality. This possibility flows from a key difference between personal computers and robots. Like PCs, open robots have no set function, run third-party software, and invite modification. But unlike PCs, personal robots are in a position directly to cause physical damage and injury. Thus, norms against suit and expedients to limit liability such as the economic loss doctrine are unlikely to transfer from the PC and consumer software context to that of robotics. This essay therefore recommends a selective immunity for manufacturers of open robotic platforms for what end users do with these platforms, akin to the immunity enjoyed under federal law by firearms manufacturers and websites. Selective immunity has the potential to preserve the conditions for innovation without compromising incentives for safety. The alternative is to risk being left behind in a key technology by countries with a higher bar to litigation and a serious head start.