Action representability of the category of internal groupoids

When $\mathbb C$ is a semi-abelian category, it is well known that the category $\mathsf{Grpd}(\mathbb C)$ of internal groupoids in $\mathbb C$ is again semi-abelian. The problem of determining whether the same kind of phenomenon occurs when the property of being semi-abelian is replaced by the one of being action representable (in the sense of Borceux, Janelidze and Kelly) turns out to be rather subtle. In the present article we give a sufficient condition for this to be true: in fact we prove that the category $\mathsf{Grpd}(\mathbb C)$ is a semi-abelian action representable algebraically coherent category with normalizers if and only if $\mathbb C$ is a semi-abelian action representable algebraically coherent category with normalizers. This result applies in particular to the categories of internal groupoids in the categories of groups, Lie algebras and cocommutative Hopf algebras, for instance.Comment: 13 page

Beira Litoral (Portugal). 1:50000

Pertenece al 'Massena's Retreat' ; N 3Orientado con flecha en cuadranteRelieve representado por normalesRelación de las principales posiciones, divisiones y cuerpos de los ejércitos indicados por clave alfabéticaIndica vegetación, caminos y las posiciones de los ejércitos por clave cromátic

NGC7538S - a High-Mass Protostar with a Massive Rotating Disk

We report the detection of a massive rotating disk around the high-mass Class 0 candidate NGC 7538S. The disk is well-resolved with BIMA (HPBW =3.7") in 3.4 mm continuum and in H13CN J = 1 - 0. It is seen nearly edge on and has a size of ~ 30,000 AU. A young, powerful outflow perpendicular to the rotating disk is mapped in SiO J = 2 - 1 and HCO+ J = 1 - 0. The dynamical age of the outflow is < 10,000 yr. The velocity gradient seen in H13CN is consistent with Keplerian rotation. Assuming that the gas is gravitationally bound, the mass of the central object is ~ 40 Msun. The mass of the continuum ``disk'' is <= 100 Msun and has a luminosity of 10^4 Lsun. H13CN gives a mass ~ 400 Msun for the rotating disk, and ~ 1000 Msun for the extended (20") envelope. Our observations confirm that this is an extremely massive protostar in its earliest stages.Comment: 11 pages (including 3 figures - 2 in color

Spinning strings in AdS_5 x S^5: A worldsheet perspective

We examine the leading Regge string states relevant for semi-classical spinning string solutions. Using elementary RNS techniques, quadratic terms in an effective lagrangian are constructed which describe massive NSNS strings in a space-time with five-form flux. We then examine the specific case of AdS_5 x S^5, finding the dependence of AdS "energy" (E_0) on spin in AdS (S), spin on the sphere (J), and orbital angular momentum on the sphere (\nabla_a \nabla^a)

An interactive application for malaria elimination transmission and costing in the Asia-Pacific

Leaders in the Asia-Pacific have endorsed an ambitious target to eliminate malaria in the region by 2030. The emergence and spread of artemisinin drug resistance in the Greater Mekong Subregion makes elimination urgent and strategic for the global goal of malaria eradication. Mathematical modelling is a useful tool for assessing and comparing different elimination strategies and scenarios to inform policymakers. Mathematical models are especially relevant in this context because of the wide heterogeneity of regional, country and local settings, which means that different strategies are needed to eliminate malaria. However, models and their predictions can be seen as highly technical, limiting their use for decision making. Simplified applications of models are needed to allow policy makers to benefit from these valuable tools. This paper describes a method for communicating complex model results with a user-friendly and intuitive framework. Using open-source technologies, we designed and developed an interactive application to disseminate the modelling results for malaria elimination. The design was iteratively improved while the application was being piloted and extensively tested by a diverse range of researchers and decision makers. This application allows several target audiences to explore, navigate and visualise complex datasets and models generated in the context of malaria elimination. It allows widespread access, use of and interpretation of models, generated at great effort and expense as well as enabling them to remain relevant for a longer period of time. It has long been acknowledged that scientific results need to be repackaged for larger audiences. We demonstrate that modellers can include applications as part of the dissemination strategy of their findings. We highlight that there is a need for additional research in order to provide guidelines and direction for designing and developing effective applications for disseminating models

All 1/2 BPS solutions of IIB supergravity with SO(4) x SO(4) isometry

In hep-th/0409174, Lin, Lunin and Maldacena constructed a set of regular 1/2 BPS geometries in IIB theory. These remarkable `bubbling AdS' geometries have a natural interpretation as duals of chiral primary operators with weight Delta=J in N=4 super-Yang Mills theory. Although these geometries have been assumed to be complete, from a purely supergravity point of view, additional 1/2 BPS configurations may potentially exist with a preferred null isometry. We explore this possibility and prove that the only additional class of 1/2 BPS solutions with SO(4) x SO(4) isometry are the familiar IIB pp-waves.Comment: 10 pages, LaTe

On the coupling of CFD and CSD methodologies for modeling blast-structure interactions

This paper describes applications of a coupled Computational Fluid Dynamics (CFD) and Computational Structural Dynamics (CSD) methodology to the simulation of blast waves generated by bare explosive charges in a test facility with rigid and deformable walls. The coupled algorithm combines FEFLO98 (CFD) and MARS3D (CSD) via an embedded approach, where the CSD objects float through the CFD domain. This combination enables an easier and more accurate prediction of structural deformation, cracking and failure under blast loading. Several experiments were conducted to characterize blast load and structural response as a function of charge size, weapon ignition point (nose or tail) and orientation (horizontal or vertical). The numerical simulations helped in understanding the experimental results, some of which were not intuitively understood. Good agreement between the experimental results and the numerical predictions were demonstrated for pressure data, blast loading and the corresponding structural response. Keywords: blast-structure interaction, coupled CFD and CSD, blast wave evolution, structural response to blast loading

A damage model based on failure threshold weakening

A variety of studies have modeled the physics of material deformation and damage as examples of generalized phase transitions, involving either critical phenomena or spinodal nucleation. Here we study a model for frictional sliding with long range interactions and recurrent damage that is parameterized by a process of damage and partial healing during sliding. We introduce a failure threshold weakening parameter into the cellular-automaton slider-block model which allows blocks to fail at a reduced failure threshold for all subsequent failures during an event. We show that a critical point is reached beyond which the probability of a system-wide event scales with this weakening parameter. We provide a mapping to the percolation transition, and show that the values of the scaling exponents approach the values for mean-field percolation (spinodal nucleation) as lattice size $L$ is increased for fixed $R$. We also examine the effect of the weakening parameter on the frequency-magnitude scaling relationship and the ergodic behavior of the model

Malaria elimination transmission and costing in the Asia-Pacific: developing an investment case

Background:; The Asia-Pacific region has made significant progress against malaria, reducing cases and deaths by over 50% between 2010 and 2015. These gains have been facilitated in part, by strong political and financial commitment of governments and donors. However, funding gaps and persistent health system challenges threaten further progress. Achieving the regional goal of malaria elimination by 2030 will require an intensification of efforts and a plan for sustainable financing. This article presents an investment case for malaria elimination to facilitate these efforts.; Methods:; A transmission model was developed to project rates of decline of; Plasmodium falciparum; and; Plasmodium vivax; malaria and the output was used to determine the cost of the interventions that would be needed for elimination by 2030. In total, 80 scenarios were modelled under various assumptions of resistance and intervention coverage. The mortality and morbidity averted were estimated and health benefits were monetized by calculating the averted cost to the health system, individual households, and society. The full-income approach was used to estimate the economic impact of lost productivity due to premature death and illness, and a return on investment was computed.; Results; : The study estimated that malaria elimination in the region by 2030 could be achieved at a cost of USD 29.02 billion (range: USD 23.65-36.23 billion) between 2017 and 2030. Elimination would save over 400,000 lives and avert 123 million malaria cases, translating to almost USD 90 billion in economic benefits. Discontinuing vector control interventions and reducing treatment coverage rates to 50% will result in an additional 845 million cases, 3.5 million deaths, and excess costs of USD 7 billion. Malaria elimination provides a 6:1 return on investment.; Conclusion:; This investment case provides compelling evidence for the benefits of continued prioritization of funding for malaria and can be used to develop an advocacy strategy