Hochster's theta invariant and the Hodge-Riemann bilinear relations

Let R be an isolated hypersurface singularity, and let M and N be finitely generated R-modules. As R is a hypersurface, the torsion modules of M against N are eventually periodic of period two (i.e., Tor_i^R(M,N) is isomorphic to Tor_{i+2}^R(M,N) for i sufficiently large). Since R has only an isolated singularity, these torsion modules are of finite length for i sufficiently large. The theta invariant of the pair (M,N) is defined by Hochster to be length(Tor_{2i}^R(M,N)) - length(Tor_{2i+1}^R(M,N)) for i sufficiently large. H. Dao has conjectured that the theta invariant is zero for all pairs (M,N) when R has even dimension and contains a field. This paper proves this conjecture under the additional assumption that R is graded with its irrelevant maximal ideal giving the isolated singularity. We also give a careful analysis of the theta pairing when the dimension of R is odd, and relate it to a classical pairing on the smooth variety Proj(R).Comment: 20 page

Can the stock market tell bank supervisors anything they don't already know?

This article provides evidence consistent with recent policy proposals calling for a greater role for market forces in promoting a safe and sound financial system. The authors' empirical results indicate a measure of expected default probability distilled from equity prices helps predict the financial condition of individual banking organizations, as reflected in their supervisory ratings. Moreover, the stock market data have predictive power over and above the information in the quarterly financial statements available to supervisors between inspections. These findings suggest financial markets can provide useful information to supplement supervisory assessments, particularly between inspections, and point to the value of additional research to further clarify the information content of market prices and quantities.Banks and banking ; Bank examination ; Bank supervision

A sex-specific reconstitution bias in the competitive CD45.1/CD45.2 congenic bone marrow transplant model.

Allelic variants of the pan-haematopoietic cell marker CD45, identified as CD45.1 and CD45.2, have been established as a marker system to track haematopoietic cells following congenic mouse bone marrow transplants. Despite the frequent use of this model for studying the impact of genetic modifications on relative differentiation potential, it is now evident that a bias exists in CD45.1 versus CD45.2 cell reconstitution. While this bias has been demonstrated by reduced reconstitution potential in B cells of CD45.1 origin, differences in the development of other lymphocytes, as well as the impact of sex on this bias, remain uncertain. We performed bone marrow transplants with wild-type CD45.1 and CD45.2 donor cells, and characterised haematopoietic cell reconstitution in dual-expressing CD45.1/2 host mice. We report an increase in CD45.2 reconstitution in the bone marrow that persists in the spleen, thymus and blood. Through the use of CD45.1/2 hosts, we demonstrate the intrinsic bias towards CD45.2 reconstitution is independent of an immunogenic response to the CD45.1 epitope. Furthermore, we identify a sex-specific difference in reconstitution efficiencies, with female mice exhibiting a greater bias towards CD45.2 reconstitution than males. This work sheds new light on the limitations of the CD45.1/CD45.2 congenic system for tracking lymphocyte development

Acute toxicity in comprehensive head and neck radiation for nasopharynx and paranasal sinus cancers: cohort comparison of 3D conformal proton therapy and intensity modulated radiation therapy.

Background: To evaluate acute toxicity endpoints in a cohort of patients receiving head and neck radiation with proton therapy or intensity modulated radiation therapy (IMRT). Methods: Forty patients received comprehensive head and neck radiation including bilateral cervical nodal radiation, given with or without chemotherapy, for tumors of the nasopharynx, nasal cavity or paranasal sinuses, any T stage, N0-2. Fourteen received comprehensive treatment with proton therapy, and 26 were treated with IMRT, either comprehensively or matched to proton therapy delivered to the primary tumor site. Toxicity endpoints assessed included g-tube dependence at the completion of radiation and at 3 months after radiation, opioid pain medication requirement compared to pretreatment normalized as equivalent morphine dose (EMD) at completion of treatment, and at 1 and 3 months after radiation. Results: In a multivariable model including confounding variables of concurrent chemotherapy and involved nodal disease, comprehensive head and neck radiation therapy using proton therapy was associated with a lower opioid pain requirement at the completion of radiation and a lower rate of gastrostomy tube dependence by the completion of radiation therapy and at 3 months after radiation compared to IMRT. Proton therapy was associated with statistically significant lower mean doses to the oral cavity, esophagus, larynx, and parotid glands. In subgroup analysis of 32 patients receiving concurrent chemotherapy, there was a statistically significant correlation with a greater opioid pain medication requirement at the completion of radiation and both increasing mean dose to the oral cavity and to the esophagus. Conclusions: Proton therapy was associated with significantly reduced radiation dose to assessed non-target normal tissues and a reduced rate of gastrostomy tube dependence and opioid pain medication requirements. This warrants further evaluation in larger studies, ideally with patient-reported toxicity outcomes and quality of life endpoints

Testosterone facilitates the sense of agency

Sense of agency (SoA) refers to feelings of being in control of one's actions. Evidence suggests that SoA might contribute towards higher-order feelings of personal control - a key attribute of powerful individuals. Whether testosterone, a steroid hormone linked to power in dominance hierarchies, also influences the SoA is not yet established. In a repeated-measures design, 26 females participated in a double-blind, placebo-controlled trial to test the effects of 0.5 mg testosterone on SoA, using an implicit measure based upon perceived shifts in time between a voluntary action and its outcome. Illusions of control, as operationalized by optimism in affective forecasting, were also assessed. Testosterone increased action binding but there was no significant effect on tone binding. Affective forecasting was found to be significantly more positive on testosterone. SoA and optimistic expectations are basic manifestations of power which may contribute to feelings of infallibility often associated with dominance and testosterone

A Note on Low-Frequency Equatorial Basin Modes

A new low-frequency standing equatorial wave mode is described. It is composed solely of long Kelvin and Rossby waves, whereas previously described low-frequency modes involved short, eastward propagating Rossby waves. It is argued that these short waves travel too slowly to allow such modes to set up. A simple closed form expression is given for the new basin mode; this is also a new form for the sum of a Kelvin wave and its eastern boundary reflection

Filtration by oysters : interactive effects of water flow, seston composition and filtration rate

Filtration by suspension-feeding bivalves affects water quality and the postulated impacts include increased light penetration and enhanced benthic primary production. Such system-level predictions are extrapolated fiom still water experiments which neglect the effects of flow, seston composition, turbulent mixing and refiltration by oysters within groups. Flume experiments were used to investigate the effects of varying flow speed and seston composition on filtration capacity of oysters. Six groups of 90 oysters were used in treatments which varied concentrations of the algae Ekalassiosira weisj70grgrsie parately and in combination with inorganics; four sets of shell only controls were used to evaluate hydrodynamic effects. The results indicate the importance of morphological differences in bed structure on turbulence and particle redistribution which may obscure biological effects and of the importance of the physiological condition of oysters on filtration capacity. Field transplants of eelgrass, Zostera marina, and American oysters, Crassostrea virgmica, were used to evaluate interactions between oyster filtration, water quality and plant survival in the field. Abnormally poor water quality forced the early termination of these experiments, but in conjunction with the flume results they indicate a strong effect of physical forces on seston distribution against which impacts of suspension feeders must judged