War Games, Analyses, and Exercises

Short of actual military operations, the Navy evaluates its combat capabilities in three ways: war games, systems or operations analyses, and exercises. The Navy uses all of these techniques extensively, and their roles often seem to overlap

Why Wargaming Works

The particulars of individual wargames are important, yet there is an undercurrent of something less tangible than facts or models that affects fundamentally the ability of a game to succeed—and to transform its participants into decision makers better able to face real-world challenges

Effects of Superconductivity and Charge Order on the sub-Terahertz reflectivity of La1.875_{1.875}Ba0.125−y_{0.125-y}Sry_{y}CuO4_4

The reflectivity $R (\omega)$ of both the $ab$ plane and the c axis of two single crystals of La$_{1.875}$Ba$_{0.125-y}$Sr$_{y}$CuO$_4$ has been measured down to 5 cm$^{-1}$, using coherent synchrotron radiation below 30 cm$^{-1}$. For $y$ = 0.085, a Josephson Plasma Resonance is detected at $T \ll T_c$ = 31 K in $R_{c} (\omega)$, and a far-infrared peak (FIP) appears in the optical conductivity below 50 K, where non-static charge ordering (CO) is reported by X-ray scattering. For $y$ = 0.05 ($T_c$ = 10 K), a FIP is observed in the low-temperature tetragonal phase below the ordering temperature $T_{CO}$. At 1/8 doping the peak frequency scales linearly with $T_{CO}$, confirming that the FIP is an infrared signature of CO, either static or fluctuating.Comment: v2: longer version, 9 pages, 6 color figure

A parallel Block Lanczos algorithm and its implementation for the evaluation of some eigenvalues of large sparse symmetric matrices on multicomputers

In the present work we describe HPEC (High Performance Eigenvalues Computation), a parallel software package for the evaluation of some eigenvalues of a large sparse symmetric matrix. It implements an efficient and portable Block Lanczos algorithm for distributed memory multicomputers. HPEC is based on basic linear algebra operations for sparse and dense matrices, some of which have been derived by ScaLAPACK library modules. Numerical experiments have been carried out to evaluate HPEC performance on a cluster of workstations with test matrices from Matrix Market and Higham’s collections. A comparison with a PARPACKroutine is also detailed. Finally, parallel performance is evaluated on random matrices, using standard parameters

Self-consistent relativistic band structure of the CH3NH3PbI3 perovskite

The electronic structure and properties of the orthorhombic phase of the CH 3 NH 3 PbI 3 perovskite are computed with density functional theory. The structure, optimized using a van der Waals functional, reproduces closely the unit cell volume. The experimental band gap is reproduced accurately by combining spin-orbit effects and a hybrid functional in which the fraction of exact exchange is tuned self-consistently to the optical dielectric constant. Including spin-orbit coupling strongly reduces the anisotropy of the effective mass tensor, predicting a low electron effective mass in all crystal directions. The computed binding energy of the unrelaxed exciton agrees with experimental data, and the values found imply a fast exciton dissociation at ambient temperature. Also polaron masses for the separated carriers are estimated. The values of all these parameters agree with recent indications that fast dynamics and large carrier diffusion lengths are key in the high photovoltaic efficiencies shown by these materials

Imatinib-mesylate for all patients with hypereosinophilic syndrome?

Some recent papers have focused on the activity of imatinib-mesylate, a selective inhibitor of tyrosine kinase, in idiopathic hypereosinophilic syndrome (HES) [1], [2], [3] and [4]. In this setting, a possible therapeutic target was identified by Cools et al. [2], who described the fusion tyrosine-kinase gene FIP1L1/PDGFRA as the result of an interstitial deletion within chromosome 4 in nine out of sixteen (56%) patients affected by HES. Of interest, although in this study the response to imatinib was strictly correlated with the presence of FIP1L1/PDGFRA rearrangement (all patients with such a molecular lesion treated with imatinib responded), only five out of nine responding patients evidenced the abnormal transcript [2]. Among the possible alternative mechanisms for the activation of the PDGFRA tyrosine-kinase domain, these authors suggested there may be a different fusion gene

C–H activation and metalation at electrode surfaces: 2,3-dimethyl-1,4-dihydroxybenzene on Pd(pc) and Pd(111) studied by TLE, HREELS and DFT

Previous studies, based on thin-layer electrochemistry (TLE), in situ scanning tunneling microscopy (EC-STM), high-resolution electron energy loss spectroscopy (HREELS) and density functional theory (DFT) computations, on the chemical adsorption of hydroquinone from aqueous solutions onto atomically smooth Pd (and Pt) electrode surfaces indicated two modes of attachment that depended upon the solution concentration. At low activities, the diphenol was oxidatively chemisorbed as benzoquinone in a flat orientation, suggestive of a Pd(2,3,5,6-η-C_6H_4O_2) surface complex; at higher concentrations, vertical chemisorption was effected via two C–H bond activations (or metalations) at the 2 and 3 ring positions, evocative of an o-phenylene organopalladium compound. We have extended the work to 2,3-dimethyl-1,4-dihydroxybenzene on Pd(pc) and Pd(111) electrodes to probe the effect of two methyl substituents on only one side of the diphenol ring. Surface coverage and adsorbed-molecule cross section data from TLE and HREELS measurements revealed non-random concentration-dependent adsorbate orientations similar to the oxidative chemisorption of hydroquinone: flat at low concentrations and edgewise at elevated concentrations. The DFT results suggested that, for the flat structure, surface coordination is via the two double bonds of the quinone ring as in [Pd(2,3,5,6-η)-2,3-dimethyl-p-quinone]. For the edge-vertical orientation, a structure analogous to an o-phenylene compound is generated in which C–H bonds at the 5 and 6 ring positions are activated and then metalated. DFT-simulated HREELS spectra helped identify the observed peaks that distinguish the surface-coordinated quinone from the surface-metalated diphenol

Bone mineral density in thalassemic children: a Brazilian experience

Osteoporosis is characterized by low bone mass and disruption of bone architecture, resulting in greater bone fragility with increased risk of fractures. Bone disease is an important cause of morbidity in beta thalassemia major patients. Osteoporosis has been described extensively in adult thalassemia. However, there are no studies describing Brazilian thalassemic children. We evaluated eleven patients with beta thalassemia major (median age of 10.0 years, range from 5 to 12 years) and twenty-four healthy children (median age of 9.5 years, range from 6 to 12 years), using dual X-ray absorptiometry to assess bone mineral density (BMD). Analysis of biochemical markers such as serum ferritin concentration, ionized calcium, alkaline phosphatase, phosphorus, albumin, prothrombin time and factor V was performed. The height was very different between the groups, p<0.05. The thalassemic patients showed significantly lower BMD (median 0.61 g/cm²) than control subjects (median 0.69 g/cm²) - p < 0.05. The relevant bone loss in the majority of thalassemic children studied emphasizes the need for identification and appropriate treatment of osteopenia, thereby reducing the morbidity of these patients. This is the first study described in the literature that determined bone mineral loss in Brazilian thalassemic children.A osteoporose, caracterizada por aumento da fragilidade óssea e suscetibilidade a fraturas, é inversamente proporcional ao pico de massa óssea adquirido na infância. Por outro lado, a doença óssea é uma importante causa de morbidade em pacientes portadores de beta-talassemia maior (TM). Apesar de intensamente descrita em pacientes talassêmicos adultos, não existem estudos sobre as alterações de densidade óssea em crianças talassêmicas brasileiras. Foram avaliados 11 pacientes (idade mediana de 10,0, variando de 5 a 12 anos), portadores de TM, e 24 crianças (idade mediana de 9,5, variando de 6 a 12 anos) saudáveis, utilizando medida de emissão dupla de raios-X para avaliar a densidade mineral óssea (DMO). A análise de marcadores bioquímicos tais como concentração de ferritina sérica, cálcio ionizado, fosfatase alcalina, fósforo, albumina, tempo de protrombina e fator V foi realizada. A estatura foi significativamente diferente entre os dois grupos estudados, p<0,05. Os pacientes talassêmicos mostraram valores significativamente inferiores de DMO (mediana 0,61 g/cm²) quando comparados aos indivíduos controles (mediana 0,69 g/cm²), p < 0,05. A relevante perda óssea encontrada na maioria das crianças talassêmicas estudadas reforça a necessidade de identificação e tratamento adequado da osteopenia, reduzindo a morbidade destes indivíduos. Este é o primeiro estudo, descrito na literatura, que avalia a DMO em crianças talassêmicas brasileiras.UNIFESP-EPMUniversidade Federal de São Paulo (UNIFESP) EPMUNIFESP, EPMUNIFESP, EPMSciEL