Comparative plastomics of Amaryllidaceae: inverted repeat expansion and the degradation of the ndh genes in Strumaria truncata Jacq.

Amaryllidaceae is a widespread and distinctive plant family contributing both food and ornamental plants. Here we present an initial survey of plastomes across the family and report on both structural rearrangements and gene losses. Most plastomes in the family are of similar gene arrangement and content however some taxa have shown gains in plastome length while in several taxa there is evidence of gene loss. Strumaria truncata shows a substantial loss of ndh family genes while three other taxa show loss of cemA, which has been reported only rarely. Our sparse sampling of the family has detected sufficient variation to suggest further sampling across the family could be a rich source of new information on plastome variation and evolution.

Evapotranspiration Estimation with the S-SEBI Method from Landsat 8 Data against Lysimeter Measurements at the Barrax Site, Spain

Evapotranspiration (ET) is a variable of the climatic system and hydrological cycle that plays an important role in biosphere–atmosphere–hydrosphere interactions. In this paper, remote sensing-based ET estimates with the simplified surface energy balance index (S-SEBI) model using Landsat 8 data were compared with in situ lysimeter measurements for different land covers (Grass, Wheat, Barley, and Vineyard) at the Barrax site, Spain, for the period 2014–2018. Daily estimates produced superior performance than hourly estimates in all the land covers, with an average difference of 12% and 15% for daily and hourly ET estimates, respectively. Grass and Vineyard showed the best performance, with an RMSE of 0.10 mm/h and 0.09 mm/h and 1.11 mm/day and 0.63 mm/day, respectively. Thus, the S-SEBI model is able to retrieve ET from Landsat 8 data with an average RMSE for daily ET of 0.86 mm/day. Some model uncertainties were also analyzed, and we concluded that the overpass of the Landsat missions represents neither the maximum daily ET nor the average daily ET, which contributes to an increase in errors in the estimated ET. However, the S-SEBI model can be used to operationally retrieve ET from agriculture sites with good accuracy and sufficient variation between pixels, thus being a suitable option to be adopted into operational ET remote sensing programs for irrigation scheduling or other purposes.

Studies on mutagenic sensitivity of seeds of pummelo (Citrus maxima Merr.)

Mutation breeding is a key method of generating a large number of heritable variations. Effective dose (LD50) needs to be standardized for inducing sufficient variation in a crop. In the present study, seeds were irradiated with different doses of Gamma rays and found that 66.94 Gy could suppress germination close to 50 percent (LD50) in pummelo. This 60 Gy gamma dose can effectively be used for raising the mutant populations to identify a desirable mutation in pummelo.

Comparative plastomics of Amaryllidaceae: Inverted repeat expansion and the degradation of the ndh genes in Strumaria truncata Jacq.

Amaryllidaceae is a widespread and distinctive plant family contributing both food and ornamental plants. Here we present an initial survey of plastomes across the family and report on both structural rearrangements and gene losses. Most plastomes in the family are of similar gene arrangement and content however some taxa have shown gains in plastome length while in several taxa there is evidence of gene loss. Strumaria truncata shows a substantial loss of ndh family genes while three other taxa show loss of cemA, which has been reported only rarely. Our sparse sampling of the family has detected sufficient variation to suggest further sampling across the family could be a rich source of new information on plastome variation and evolution.

Highly parallel genomic selection response in replicated Drosophila melanogaster populations with reduced genetic variation

Many adaptive traits are polygenic and frequently more loci contributing to the phenotype than needed are segregating in populations to express a phenotypic optimum. Experimental evolution provides a powerful approach to study polygenic adaptation using replicated populations adapting to a new controlled environment. Since genetic redundancy often results in non-parallel selection responses among replicates, we propose a modified Evolve and Resequencing (E&R) design that maximizes the similarity among replicates. Rather than starting from many founders, we only use two inbred Drosophila melanogaster strains and expose them to a very extreme, hot temperature environment (29°C). After 20 generations, we detect many genomic regions with a strong, highly parallel selection response in 10 evolved replicates. The X chromosome has a more pronounced selection response than the autosomes, which may be attributed to dominance effects. Furthermore, we find that the median selection coefficient for all chromosomes is higher in our two-genotype experiment than in classic E&R studies. Since two random genomes harbor sufficient variation for adaptive responses, we propose that this approach is particularly well-suited for the analysis of polygenic adaptation.

On the potential of Angiosperms353 for population genomics

Targeted sequencing using Angiosperms353 has emerged as a low-cost tool for phylogenetics, with early results spanning scales from all flowering plants to within genera. The use of universal markers at narrower scales—within populations— would eliminate the need for specific marker development while retaining the benefits of full-gene sequences. However, it is unclear whether the Angiosperms353 markers provide sufficient variation within species to calculate demographic parameters. Using herbarium specimens from a 50-year-old floristic survey of Guadalupe Mountains National Park, we sequenced 95 samples from 24 species using Angiosperms353. We adapted a data workflow to process targeted sequencing data that calls variants within each species and prepares data for population genetic analysis. We calculated genetic diversity using standard metrics (e.g. heterozygosity, Tajima’s D). Angiosperms353 gene recovery was associated with genomic library concentration, with limited phylogenetic bias. We identified over 1000 segregating variants with zero missing data within 22 of 24 species. A subset of these variants, which were filtered to remove linked SNPs, revealed high heterozygosity in many species. Tajima’s D calculated within each species indicated a moderate number of markers potentially under selection and identified evidence of population bottlenecks in some species. Despite sequencing few individuals per species, the Angiosperms353 markers contained sufficient variation calculate demographic parameters. Larger sampling within species will allow for estimating gene flow and population dynamics in any angiosperm. Our study will benefit conservation genetics, where Angiosperms353 provides universal repeatable markers, low missing data, and haplotype information.

Predator diversity and thermal niche complementarity attenuate indirect effects of warming on prey survival

Climate warming has broad-reaching effects on communities, and although much research has focused on direct abiotic effects, indirect effects of warming meditated through biotic interactions can be of equal or greater magnitude. A body of theoretical and empirical work has developed examining the effects of climate warming on predator-prey interactions, but most studies have focused on single predator and prey species. We develop a model with multiple predator species using simulated and measured predator thermal niches from a community of ants, to examine the influence of predator diversity and other aspects of community thermal niche on the indirect effects of climate warming on prey survival probability. We find that predator diversity attenuates the indirect effect of climate warming on prey survival probability, and that sufficient variation of predator thermal optima, closer prey and mean predator thermal optima, and higher predator niche complementarity increases the attenuation effect of predator diversity. We predict therefore that more diverse and complementary communities are likely more affected by direct versus indirect effects of climate warming, and vice versa for less diverse and complementary communities. If general, these predictions could lessen the difficulty of predicting the effects of climate warming on a focal species of interest.

Bureaucracy and Growth

We revisit the hypothesis that a Weberian bureaucracy enhances economic growth. Theoretically, we develop arguments for why such a bureaucracy may enhance growth and discuss plausible counterarguments. Empirically, we use new measures capturing various Weberian features in countries across the world, with some time series extending back to 1789. The evidence base from previous large- N studies is surprisingly thin, but our extensive data enable us to move beyond the problematic cross-country correlations used in previous studies. Hence, we conduct tests that control for country-specific characteristics while ensuring sufficient variation on the slow-moving bureaucracy variables to enable precise estimation. Our analysis suggests that previous cross-country regressions have vastly overstated the strength of the relationship. While this casts uncertainty on the proposition that there is an effect of Weberian bureaucracy on growth, our further analysis suggests that—if an effect exists—it may operate in the short term and be stronger in recent decades.

The Effects of the Type and Content of Audit Reports for Financially Stressed Initial Public Offerings on Information Uncertainty

SUMMARY The Public Company Accounting Oversight Board (PCAOB) has expressed concern that audit reports do not contain sufficient variation to provide useful information to the market. Using a sample of financially stressed initial public offering (IPO) firms, we investigate whether information uncertainty is affected by (1) three different types of audit reports—unqualified (clean), hybrid (with explanatory language about financial stress), and going concern (GCAR)—and (2) audit report disclosures. We provide evidence that audit reports (hybrid and GCAR) and audit report disclosures provide useful information to the market by finding a significant reduction in information uncertainty. Just as important, we find that management discretionary going concern disclosures do not complement or substitute for the reduction in information uncertainty associated with hybrid audit reports and GCARs. We provide evidence that current audit report types and disclosures of financially stressed IPO firms provide information to the market. JEL Classifications: M40; M42; G14. Data Availability: The data used in this study are available from public sources indicated in the paper.

Precise timing is ubiquitous, consistent, and coordinated across a comprehensive, spike-resolved flight motor program

Sequences of action potentials, or spikes, carry information in the number of spikes and their timing. Spike timing codes are critical in many sensory systems, but there is now growing evidence that millisecond-scale changes in timing also carry information in motor brain regions, descending decision-making circuits, and individual motor units. Across all of the many signals that control a behavior, how ubiquitous, consistent, and coordinated are spike timing codes? Assessing these open questions ideally involves recording across the whole motor program with spike-level resolution. To do this, we took advantage of the relatively few motor units controlling the wings of a hawk moth,Manduca sexta. We simultaneously recorded nearly every action potential from all major wing muscles and the resulting forces in tethered flight. We found that timing encodes more information about turning behavior than spike count in every motor unit, even though there is sufficient variation in count alone. Flight muscles vary broadly in function as well as in the number and timing of spikes. Nonetheless, each muscle with multiple spikes consistently blends spike timing and count information in a 3:1 ratio. Coding strategies are consistent. Finally, we assess the coordination of muscles using pairwise redundancy measured through interaction information. Surprisingly, not only are all muscle pairs coordinated, but all coordination is accomplished almost exclusively through spike timing, not spike count. Spike timing codes are ubiquitous, consistent, and essential for coordination.