Finite Horizon Learning

Incorporating adaptive learning into macroeconomics requires assumptions about how agents incorporate their forecasts into their decision-making. We develop a theory of bounded rationality that we call finite-horizon learning. This approach generalizes the two existing benchmarks in the literature: Eulerequation learning, which assumes that consumption decisions are made to satisfy the one-step-ahead perceived Euler equation; and infinite-horizon learning, in which consumption today is determined optimally from an infinite-horizon optimization problem with given beliefs. In our approach, agents hold a finite forecasting/planning horizon. We find for the Ramsey model that the unique rational expectations equilibrium is E-stable at all horizons. However, transitional dynamics can differ significantly depending upon the horizon.

Stochastic Choice and Consideration Sets

We model a boundedly rational agent who suffers from limited attention. The agent considers each feasible alternative with a given (unobservable) probability, the attention parameter, and then chooses the alternative that maximises a preference relation within the set of considered alternatives. We show that this random choice rule is the only one for which the impact of removing an alternative on the choice probability of any other alternative is asymmetric and menu independent. Both the preference relation and the attention parameters are identi fied uniquely by stochastic choice data.

Imperfect Attention and Menu Evaluation

We model the choice behaviour of an agent who suffers from imperfect attention. We define inattention axiomatically through preference over menus and endowed alternatives: an agent is inattentive if it is better to be endowed with an alternative a than to be allowed to pick a from a menu in which a is is the best alternative. This property and vNM rationality on the domain of menus and alternatives imply that the agent notices each alternative with a given menu-dependent probability (attention parameter) and maximises a menu independent utility function over the alternatives he notices. Preference for flexibility restricts the model to menu independent attention parameters as in Manzini and Mariotti [19]. Our theory explains anomalies (e.g. the attraction and compromise effect) that the Random Utility Model cannot accommodate.

Competing for Attention: Is the Showiest also the Best?

We introduce attention games. Alternatives ranked by quality (producers, politicians, sexual partners...) desire to be chosen and compete for the imperfect attention of a chooser by investing in their own salience. We prove that if alternatives can control the attention they get, then ”the showiest is the best”: the equilibrium ordering of salience (weakly) reproduces the quality ranking and the best alternative is the one that gets picked most often. This result also holds under more general conditions. However, if those conditions fail, then even the worst alternative can be picked most often.

Positive solutions of nonlinear problems involving the square root of the Laplacian

We consider nonlinear elliptic problems involving a nonlocal operator: the square root of the Laplacian in a bounded domain with zero Dirichlet boundary conditions. For positive solutions to problems with power nonlinearities, we establish existence and regularity results, as well as a priori estimates of Gidas-Spruck type. In addition, among other results, we prove a symmetry theorem of Gidas-Ni-Nirenberg type.

Ultrastructural and stereological analysis of trypanosomatidis of the genus Endotrypanum

Culture forms of four strains of Endotrypanum (E. schaudinni and E. monterogeii) were processed for transmission electron microscopy and analyzed at the ultrastructural level. Quantitative data about some cytoplasmic organelles were obeined by stereology. All culture forms were promastigotes. In their cytoplasm four different organelles could be found: lipid inclusions (0,2-0,4 µm in diameter), mebrane-bounded vacuoles (0.10-0,28 µm in diameter), glycosomes (0,2-0,3 µm in diameter), and the mitochondrion. The kenetoplast appears as a thin band, except for the strain IM201, which possesses a broader structure, and possibly is not a member of this genus. Clusters of virus-like particles were seen in the cytoplasm of the strain LV88. The data obtained show that all strains have the typical morphological feature of the trypanosomatids. Only strain IM201 could be differentiated from the others, due to its larger kenetoplast-DNA network and its large mitochondrial and glycosomal relative volume. The morphometrical data did not allow the differentiation between E. schaudinni (strains IM217 and M6226) and E. monterogeii (strain LV88).

Experimental design for acquiring relevant data to address the issue of comparing consecutively manufactured tools and firearms

The comparison of consecutively manufactured tools and firearms has provided much, but not all, of the basis for the profession of firearm and toolmark examination. The authors accept the fundamental soundness of this approach but appeal to the experimental community to close two minor gaps in the experimental procedure. We suggest that "blinding" and attention to appropriateness of other experimental conditions that would consolidate the foundations of our profession. We do not suggest that previous work is unsound.

Condensation of polyhedric structures onto soap films

We study the existence of solutions to general measure-minimization problems over topological classes that are stable under localized Lipschitz homotopy, including the standard Plateau problem without the need for restrictive assumptions such as orientability or even rectifiability of surfaces. In case of problems over an open and bounded domain we establish the existence of a “minimal candidate”, obtained as the limit for the local Hausdorff convergence of a minimizing sequence for which the measure is lower-semicontinuous. Although we do not give a way to control the topological constraint when taking limit yet— except for some examples of topological classes preserving local separation or for periodic two-dimensional sets — we prove that this candidate is an Almgren-minimal set. Thus, using regularity results such as Jean Taylor’s theorem, this could be a way to find solutions to the above minimization problems under a generic setup in arbitrary dimension and codimension.

Rapid diagnostic tests for non-malarial febrile illness in the tropics.

The recent roll-out of rapid diagnostic tests (RDTs) for malaria has highlighted the decreasing proportion of malaria-attributable illness in endemic areas. Unfortunately, once malaria is excluded, there are few accessible diagnostic tools to guide the management of severe febrile illnesses in low resource settings. This review summarizes the current state of RDT development for several key infections, including dengue fever, enteric fever, leptospirosis, brucellosis, visceral leishmaniasis and human African trypanosomiasis, and highlights many remaining gaps. Most RDTs for non-malarial tropical infections currently rely on the detection of host antibodies against a single infectious agent. The sensitivity and specificity of host-antibody detection tests are both inherently limited. Moreover, prolonged antibody responses to many infections preclude the use of most serological RDTs for monitoring response to treatment and/or for diagnosing relapse. Considering these limitations, there is a pressing need for sensitive pathogen-detection-based RDTs, as have been successfully developed for malaria and dengue. Ultimately, integration of RDTs into a validated syndromic approach to tropical fevers is urgently needed. Related research priorities are to define the evolving epidemiology of fever in the tropics, and to determine how combinations of RDTs could be best used to improve the management of severe and treatable infections requiring specific therapy.

Keeping the leaves green above us.

The plant immune system relies to a great extent on the highly regulated expression of hundreds of defense genes encoding antimicrobial proteins, such as defensins, and antiherbivore proteins, such as lectins. The expression of many of these genes is controlled by a family of mediators known as jasmonates; these cyclic oxygenated fatty acid derivatives are reminiscent of prostaglandins. The roles of jasmonates also extend to the control of reproductive development. How are these complex events regulated? Nearly 20 members of the jasmonate family have been characterized. Some, like jasmonic acid, exist in unmodified forms, whereas others are conjugated to other lipids or to hydrophobic amino acids. Why do so many chemically different forms of these mediators exist, and do individual jasmonates have unique signaling properties or are they made to facilitate transport within and between cells? Key features of the jasmonate signal pathway have been identified and include the specific activation of E3-type ubiquitin ligases thought to target as-yet-undescribed transcriptional repressors for modification or destruction. Several classes of transcription factor are known to function in the jasmonate pathway, and, in some cases, these proteins provide nodes that integrate this network with other important defensive and developmental pathways. Progress in jasmonate research is now rapid, but large gaps in our knowledge exist. Aimed to keep pace with progress, the ensemble of jasmonate Connections Maps at the Signal Transduction Knowledge Environment describe (i) the canonical signaling pathway, (ii) the Arabidopsis signaling pathway, and (iii) the biogenesis and structures of the jasmonates themselves.

Rigorous derivation of a nonlinear diffusion equation as fast-reaction limit of a continuous coagulation-fragmentation model with diffusion

Weak solutions of the spatially inhomogeneous (diffusive) Aizenmann-Bak model of coagulation-breakup within a bounded domain with homogeneous Neumann boundary conditions are shown to converge, in the fast reaction limit, towards local equilibria determined by their mass. Moreover, this mass is the solution of a nonlinear diffusion equation whose nonlinearity depends on the (size-dependent) diffusion coefficient. Initial data are assumed to have integrable zero order moment and square integrable first order moment in size, and finite entropy. In contrast to our previous result [CDF2], we are able to show the convergence without assuming uniform bounds from above and below on the number density of clusters.

Regularity and mass conservation for discrete coagulation-fragmentation equations with diffusion

We present a new a-priori estimate for discrete coagulation fragmentation systems with size-dependent diffusion within a bounded, regular domain confined by homogeneous Neumann boundary conditions. Following from a duality argument, this a-priori estimate provides a global L2 bound on the mass density and was previously used, for instance, in the context of reaction-diffusion equations. In this paper we demonstrate two lines of applications for such an estimate: On the one hand, it enables to simplify parts of the known existence theory and allows to show existence of solutions for generalised models involving collision-induced, quadratic fragmentation terms for which the previous existence theory seems difficult to apply. On the other hand and most prominently, it proves mass conservation (and thus the absence of gelation) for almost all the coagulation coefficients for which mass conservation is known to hold true in the space homogeneous case.

Polyanalgesic Consensus Conference--2012: recommendations on trialing for intrathecal (intraspinal) drug delivery: report of an interdisciplinary expert panel.

INTRODUCTION: Trialing for intrathecal pump placement is an essential part of the decision-making process in placing a permanent device. In both the United States and the international community, the proper method for trialing is ill defined. METHODS: The Polyanalgesic Consensus Conference (PACC) is a group of well-published experienced practitioners who meet to update the state of care for intrathecal therapies on the basis of current knowledge in the literature and clinical experience. Anexhaustive search is performed to create a base of information that the panel considers when making recommendations for best clinical practices. This literature, coupled with clinical experience, is the basis for recommendations and for identification of gaps in the base of knowledge regarding trialing for intrathecal pump placement. RESULTS: The panel has made recommendations for the proper methods of trialing for long-term intrathecal drug delivery. CONCLUSION: The use of intrathecal drug delivery is an important part of the treatment algorithm for moderate to severe chronic pain. It has become common practice to perform a temporary neuroaxial infusion before permanent device implantation. On the basis of current knowledge, the PACC has developed recommendations to improve care. The need to update these recommendations will be very important as new literature is published.

The Brezis-Nirenberg type problem involving the square root of the Laplacian

We establish existence and non-existence results to the Brezis-Nirenberg type problem involving the square root of the Laplacian in a bounded domain with zero Dirichlet boundary condition.

Portal hypertension in schistosomiasis: pathophysiology and treatment

In heavily infected young patients, there is a "non-congestive" phase of the disease with splenomegaly which can improve after chemoterapy. A strong correlation between hepatosplenic form and worm burden in young patients has been repeatedly shown. The pattern of vascular intrhepatic lesions seems to depend on two mechanisms: (a) egg embolization, with a partial blocking of the portal vasculature; (b) the appearance of small portal collaterals along the intrahepatic portal sistem. The role played by hepatitis B virus (HBV) and C virus infections in the pathogenesis of liver lesions is variably considered. Selective arteriography shows a reduced diameter of hepatic artery with thin and arched branches outlining vascular gaps. A rich arterial network , as described in autopsy cases, is usually not seen in vivo, except after splenectomy or shunt surgery. An augmented hepatic arterial flow was demonstrated in infected animals. These facts suggest that the poor intrahepatic arterial vascularization demonstrated by selective arteriography in humans is due to a "functional deviation"of arterial blood to the splenic territory. The best results obtained in treatment of portal hypertension were: esophagogastric desvascularization and splenectomy (EGDS), although risk of rebleeding persists; classical (proximal) splenorenal shunt (SRS) should be abandoned; distal splenorenal shunt may complicate with hepatic encephalopaty, although later and in a lower percentage than in SRS. Propranolol is currently under investigation. In our Department, schistosomotic patients with esophageal varices bleeding are treated by EGDS and, if rebleeding occurs, by sclerosis of the varices.