Small representations, string instantons, and Fourier modes of Eisenstein series (with an appendix by D. Ciubotaru and P. Trapa)

This paper concerns some novel features of maximal parabolic Eisenstein series at certain special values of their analytic parameter s. These series arise as coefficients in the R4 and D4R4 interactions in the low energy expansion of scattering amplitudes in maximally supersymmetric string theory reduced to D=10-d dimensions on a torus T^d, d<8. For each d these amplitudes are automorphic functions on the rank d+1 symmetry group E_d+1. Of particular significance is the orbit content of the Fourier modes of these series when expanded in three different parabolic subgroups, corresponding to certain limits of string theory. This is of interest in the classification of a variety of instantons that correspond to minimal or next-to-minimal BPS orbits. In the limit of decompactification from D to D+1 dimensions many such instantons are related to charged 1/2-BPS or 1/4-BPS black holes with euclidean world-lines wrapped around the large dimension. In a different limit the instantons give nonperturbative corrections to string perturbation theory, while in a third limit they describe nonperturbative contributions in eleven-dimensional supergravity. A proof is given that these three distinct Fourier expansions have certain vanishing coefficients that are expected from string theory. In particular, the Eisenstein series for these special values of s have markedly fewer Fourier coefficients than typical ones. The corresponding mathematics involves showing that the wavefront sets of the Eisenstein series are supported on only certain coadjoint nilpotent orbits - just the minimal and trivial orbits in the 1/2-BPS case, and just the next-to-minimal, minimal and trivial orbits in the 1/4-BPS case. Thus as a byproduct we demonstrate that the next-to-minimal representations occur automorphically for E6, E7, and E8, and hence the first two nontrivial low energy coefficients are exotic theta-functions.Comment: v3: 127 pp. Minor changes. Final version to appear in the Special Issue in honor of Professor Steve Ralli

Eisenstein series for higher-rank groups and string theory amplitudes

Scattering amplitudes of superstring theory are strongly constrained by the requirement that they be invariant under dualities generated by discrete subgroups, E_n(Z), of simply-laced Lie groups in the E_n series (n<= 8). In particular, expanding the four-supergraviton amplitude at low energy gives a series of higher derivative corrections to Einstein's theory, with coefficients that are automorphic functions with a rich dependence on the moduli. Boundary conditions supplied by string and supergravity perturbation theory, together with a chain of relations between successive groups in the E_n series, constrain the constant terms of these coefficients in three distinct parabolic subgroups. Using this information we are able to determine the expressions for the first two higher derivative interactions (which are BPS-protected) in terms of specific Eisenstein series. Further, we determine key features of the coefficient of the third term in the low energy expansion of the four-supergraviton amplitude (which is also BPS-protected) in the E_8 case. This is an automorphic function that satisfies an inhomogeneous Laplace equation and has constant terms in certain parabolic subgroups that contain information about all the preceding terms.Comment: Latex. 38 pages. 1 figure. v2: minor changes and clarifications. v3: minor corrections, version to appear in Communications in Number Theory and Physics. v4: corrections to table

Combining High Yields and Blast Resistance in Rice (Oryza spp.): A Screening under Upland and Lowland Conditions in Benin

The future security of the supply of rice for food in Africa depends on improving the level of local production to achieve self-sufficiency. In order to cope with the existing gap between production and actual demand, combining a high level of rice blast tolerance and a high-yield potential is necessary. The current study was conducted under upland and lowland conditions in Benin to gain insight into the performance of selected blast-resistant accessions along with some currently grown varieties. This study revealed a high phenotypic variability among these accessions. Furthermore, differences in the performance of these accessions under lowland and upland conditions were observed. Principal component analysis showed their grouping in three clusters. The analysis also demonstrated a high yield potential among the blast-resistant rice accessions whether they were Oryza sativa or O. glaberrima. Furthermore, there was a significant correlation between yield and both spikelet fertility and growth cycle duration. In conclusion, the present study identified promising rice accessions for future breeding. High phenotypic variability in combination with interesting traits can help to develop new resilient varieties. Finally, when the traits correlate with yield, they can be used as markers for an early screening method for identifying promising accessions at an early stage

Assessing paleotemperature and seasonality during the early Eocene climatic optimum (EECO) in the Belgian basin by means of fish otolith stable O and C isotopes

The Paleogene greenhouse world comprises variable paleoclimate conditions providing an indispensable deep-time perspective for the possible effects of human-induced climate change. In this paper, paleotemperature data of the Early Eocene Climatic Optimum (EECO) from the mid-latitude marginal marine Belgian Basin are discussed. They are derived from fish otolith d18O compositions of four non-migratory species belonging to the families Congridae and Ophidiidae. Otoliths from several levels and localities within the middle to late Ypresian were selected. After manual polishing, bulk and incremental microsamples were drilled and analyzed by a mass spectrometer. A cross-plot of bulk otolith d18O vs. d13C results shows a discrepancy between both families used. Ophidiid data probably represent true bottom water temperatures of the Belgian Basin. The mean annual temperature (MAT) of the EECO is calculated at 27.5 °C, which is in line with other proxy results. However, variations in MAT up to 6 °C occur, suggesting a pronounced expression of climate variability in mid-latitude marginal basins. Incremental analyses revealed a ~9.5 °C mean annual range of temperatures, similar to modern seasonality. These results show that marginal marine environments such as the Belgian Basin are well suited to infer high-resolution paleoclimate variability

Intra- and intertaxon stable O and C isotope variability of fossil fish otoliths: an early Eocene test case

Knowledge of basic data variability is essential for the interpretation of any proxy-based paleotemperature record. To evaluate this for d18O stable isotope paleothermometry based on early Paleogene fish otoliths from marginal marine environments, an intra- and interspecific stable O and C isotope study was performed at a single locality in the southern North Sea Basin (Ampe Quarry, Egem, Belgium), where shallow marine sands and silts are exposed. The age of the deposits is early late Ypresian (ca. 50.9 Ma) and falls within the early Eocene climatic optimum (EECO) interval. In each of four fossiliferous levels sampled, the same three otolith species were analyzed (Platycephalus janeti, Paraconger papointi and “genus Neobythitinorum” subregularis). Intrataxon stable isotope spread amounts on average 2.50-3.00‰ for all taxa and is present in all levels. This implies that each sample level comprises substantial variability, which can be attributed to a combination of temporal and taphonomic effects. More importantly, intertaxon offsets of 4.60‰ in d13C and 2.20‰ in d18O between the mean values of the three otolith species are found, with “N.” subregularis representing more positive values relative to the other species. We hypothesize that freshwater influence of coastal waters is the most likely cause for these discrepancies. Similar analyses on two coastal bivalve species (Venericardia sulcata and Callista laevigata) corroborate this hypothesis. Accordingly, d18O values measured on “N.” subregularis otoliths probably represent a more open oceanic signal, and therefore seem well-suited for d18O stable isotope paleothermometry. This study highlights the importance of investigating data variability of a biogenic carbonate paleotemperature proxy at the species level, before applying paleotemperature equations and interpreting the outcome

String loop corrections to the universal hypermultiplet

We study loop corrections to the universal dilaton supermultiplet for type IIA strings compactified on Calabi-Yau threefolds. We show that the corresponding quaternionic kinetic terms receive non-trivial one-loop contributions proportional to the Euler number of the Calabi-Yau manifold, while the higher-loop corrections can be absorbed by field redefinitions. The corrected metric is no longer Kahler. Our analysis implies in particular that the Calabi-Yau volume is renormalized by loop effects which are present even in higher orders, while there are also one-loop corrections to the Bianchi identities for the NS and RR field strengths.Comment: 30 pages, harvmac, 1 figure. v2: minor typos corrected. Version to appear in Classical and Quantum Gravit

The Comprehensive Soldier and Family Fitness Program Evaluation. Report #4: Evaluation of Resilience Training and Mental and Behavioral Health Outcomes

The purpose of this evaluation is to examine the effectiveness of Master Resilience Training, which is a pillar of the Comprehensive Soldier and Family Fitness (CSF2) program. The report evaluates the relationship between resilience training and diagnoses for mental health or substance abuse problems and whether this relationship was mediated by Soldiers’ self-reported resilience/ psychological health (R/PH). In other words, we tested whether Soldiers with MRT trainers in their units experienced increases in self-reported R/PH, and whether increases in self-reported R/PH were associated with reduced odds of Soldiers receiving diagnoses for mental health or substance abuse problems. The results revealed that exposure to resilience training increased various aspects of Soldier R/PH, which, in turn, appeared to be associated with a reduced likelihood of receiving a diagnosis for a mental health problem (i.e., anxiety, depression, or posttraumatic stress disorder [PTSD]). Thus, this finding suggested that the reduced odds of receiving a diagnosis for a mental health problem was partly due to increases in indicators of R/PH that were likely associated with exposure to resilience training. Moreover, the findings provided evidence that Soldiers exposed to the training were diagnosed with substance abuse problems at a significantly lower rate than Soldiers who were not exposed to the training. Importantly, the results of this evaluation bolster findings from previous evaluations by employing more sophisticated and stringent statistical techniques to demonstrate that resilience training can improve the R/PH of Soldiers. Additionally, the analyses included in this evaluation accounted for the potential effects of Soldier deployment; these considerations were not made in previous evaluations of the program. Therefore, the current evaluation provides further evidence that resilience training may improve the self-reported R/PH of Soldiers, even when controlling for a wider range of factors that might be expected to impact the R/PH of Soldiers. The findings of this evaluation have a number of implications. First, this evaluation provides some evidence that resilience training may be related to improvements on objective measures of mental and behavioral outcomes (i.e., diagnoses for mental health and substance abuse problems). Second, when considered at the organizational level, the effects of resilience training may reach beyond improving the health of individual Soldiers by improving the aggregate health and effectiveness of the Army as an organization. Given that diagnoses for mental health disorders are a leading cause for hospitalization in the Armed Forces (Armed Forces Health Surveillance Center, 2012b), the findings provide evidence that interventions such as those offered by CSF2 may help relieve the stress that is currently being placed on medical services in the Army. In sum, it appears that the improvement of R/PH through resilience training efforts can protect against problems that undermine the effectiveness and efficiency of the Army. As with any large-scale evaluation of this type, there are a number of limitations to be acknowledged. First, the timing of deployment cycles of Soldiers in the eight Brigade Combat Teams (BCTs) that were examined introduced potential confounds with regard to the timing of resilience training and data collection efforts for use in this report. Specifically, it appeared that the timing of deployments was such that Soldiers with MRTs in their units were more likely to have been deployed to combat than were those who had no MRT trainers in their units. This means that Soldiers who received resilience training were also more likely to have experienced combat which likely increased the probability of subsequently experiencing the adverse outcomes examined in this study. While this fact posed a potential confound, statistical controls were put in place that allowed for a meaningful test of the resilience training program’s effect on R/PH and diagnoses for mental health and substance abuse problems. Other limitations of this evaluation effort have been described elsewhere (Lester, Harms, Herian, Krasikova & Beal, 2011c) and are expanded upon later in this report. In light of these limitations, it is important that readers recognize two points when reviewing this report. First, this report builds on previous evaluations of the CSF2 program. Specifically, the analyses used here were more stringent given the nature of the data. It is important to note that, given the more rigorous testing methods, the results of this and previous evaluations are fairly consistent. Second, it is critical to recognize that the findings presented in this report represent the latest effort in an ongoing evaluation of the resilience training program. Future analyses may also be conducted that empirically explore the relationship between resilience training and other objective outcomes. If such analyses are undertaken, it is possible that the results may differ from those presented here and in previous evaluations due to the amount of time that has passed since implementation of the training program. In the end, however, the effectiveness of CSF2 cannot be judged solely on the results of any single evaluation, but instead must be considered in light of the entire body of work done to date

The first next-generation sequencing approach to the mitochondrial phylogeny of African monogenean parasites (Platyhelminthes: Gyrodactylidae and Dactylogyridae)

Abstract Background Monogenean flatworms are the main ectoparasites of fishes. Representatives of the species-rich families Gyrodactylidae and Dactylogyridae, especially those infecting cichlid fishes and clariid catfishes, are important parasites in African aquaculture, even more so due to the massive anthropogenic translocation of their hosts worldwide. Several questions on their evolution, such as the phylogenetic position of Macrogyrodactylus and the highly speciose Gyrodactylus, remain unresolved with available molecular markers. Also, diagnostics and population-level research would benefit from the development of higher-resolution genetic markers. We aim to offer genetic resources for work on African monogeneans by providing mitogenomic data of four species (two belonging to Gyrodactylidae, two to Dactylogyridae), and analysing their gene sequences and gene order from a phylogenetic perspective. Results Using Illumina technology, the first four mitochondrial genomes of African monogeneans were assembled and annotated for the cichlid parasites Gyrodactylus nyanzae, Cichlidogyrus halli, Cichlidogyrus mbirizei (near-complete mitogenome) and the catfish parasite Macrogyrodactylus karibae (near-complete mitogenome). Complete nuclear ribosomal operons were also retrieved, as molecular vouchers. The start codon TTG is new for Gyrodactylus and for Dactylogyridae, as is the incomplete stop codon TA for Dactylogyridae. Especially the nad2 gene is promising for primer development. Gene order was identical for protein-coding genes and differed between the African representatives of these families only in a tRNA gene transposition. A mitochondrial phylogeny based on an alignment of nearly 12,500 bp including 12 protein-coding and two ribosomal RNA genes confirms that the Neotropical oviparous Aglaiogyrodactylus forficulatus takes a sister group position with respect to the other gyrodactylids, instead of the supposedly ‘primitive’ African Macrogyrodactylus. Inclusion of the African Gyrodactylus nyanzae confirms the paraphyly of Gyrodactylus. The position of the African dactylogyrid Cichlidogyrus is unresolved, although gene order suggests it is closely related to marine ancyrocephalines. Conclusions The amount of mitogenomic data available for gyrodactylids and dactylogyrids is increased by roughly one-third. Our study underscores the potential of mitochondrial genes and gene order in flatworm phylogenetics, and of next-generation sequencing for marker development for these non-model helminths for which few primers are available

An R^4 non-renormalisation theorem in N=4 supergravity

We consider the four-graviton amplitudes in CHL constructions providing four-dimensional N=4 models with various numbers of vector multiplets. We show that in these models the two-loop amplitude has a prefactor of d^2R^4. This implies a non-renormalisation theorem for the R^4 term, which forbids the appearance of a three-loop ultraviolet divergence in four dimensions in the four-graviton amplitude. We connect the special nature of the R^4 term to the U(1) anomaly of pure N=4 supergravity.Comment: v2: added comments about one-loop UV divergences. Assorted stylistic corrections. Added references. v3: Eq. III.21 corrected and assorted minor corrections and clarifications. Version to be published. v4: minor corrections. 18 pages. one figur