catena-Poly[[[diaqua­(nitrato-κ2 O,O′)(2,2′:6′,2′′-terpyridine-κ3 N,N′,N′′)ytterbium(III)]-μ-cyanido-κ2 N:C-[dicyanido­platinum(II)]-μ-cyanido-κ2 C:N] acetonitrile monosolvate]

The title compound, {[PtYb(CN)4(NO3)(C15H11N3)(H2O)2]·CH3CN}n, was isolated from solution as a one-dimensional coordination polymer. The Yb3+ site has ninefold coordination with a distorted tricapped trigonal–prismatic geometry, while the PtII ion is coordinated by four cyanide groups in an almost regular square-planar geometry. cis-Bridging by the tetra­cyanidoplatinate(II) anions links the Yb3+ cations, forming chains. Additionally, each Yb3+ is coordinated by two water mol­ecules, one bidentate nitrate anion, and one tridentate 2,2′:6′,2′′-terpyridine mol­ecule. O—H⋯N hydrogen-bonding inter­actions are found between adjacent chains and help to consolidate the crystal packing. In addition, π–π stacking inter­actions exist between the terpyridine ligand and the two corresponding terpyridine ligands along the adjacent chain (average inter­planar distance = 3.667 Å). Moderate Pt⋯Pt inter­actions [3.5033 (4) Å] are observed in the structure

Prisoner's Dilemma cellular automata revisited: evolution of cooperation under environmental pressure

We propose an extension of the evolutionary Prisoner's Dilemma cellular automata, introduced by Nowak and May \cite{nm92}, in which the pressure of the environment is taken into account. This is implemented by requiring that individuals need to collect a minimum score $U_{min}$, representing indispensable resources (nutrients, energy, money, etc.) to prosper in this environment. So the agents, instead of evolving just by adopting the behaviour of the most successful neighbour (who got $U^{msn}$), also take into account if $U^{msn}$ is above or below the threshold $U_{min}$. If $U^{msn}<U_{min}$ an individual has a probability of adopting the opposite behaviour from the one used by its most successful neighbour. This modification allows the evolution of cooperation for payoffs for which defection was the rule (as it happens, for example, when the sucker's payoff is much worse than the punishment for mutual defection). We also analyse a more sophisticated version of this model in which the selective rule is supplemented with a "win-stay, lose-shift" criterion. The cluster structure is analyzed and, for this more complex version we found power-law scaling for a restricted region in the parameter space.Comment: 15 pages, 8 figures; added figures and revised tex

A solvable model of the evolutionary loop

A model for the evolution of a finite population in a rugged fitness landscape is introduced and solved. The population is trapped in an evolutionary loop, alternating periods of stasis to periods in which it performs adaptive walks. The dependence of the average rarity of the population (a quantity related to the fitness of the most adapted individual) and of the duration of stases on population size and mutation rate is calculated.Comment: 6 pages, EuroLaTeX, 1 figur

A nearly planar arrangement of ions in 4,4′-bipiperidinium tetra­cyanido­platinate(II) monohydrate

The title compound, (C10H22N2)[Pt(CN)4]·H2O, was isolated from solution as a mol­ecular salt. The compound contains discrete 4,4′-bipiperidinium cations and tetra­cyano­platinate(II) anions that are involved in a hydrogen-bonding network with one water mol­ecule of hydration. The structure differs from that of the similar acetonitrile solvate, (C10H22N2)[Pt(CN)4]·2CH3CN, in the orientation of the ions relative to one another. The hydrate reported here contains layers of nearly parallel cations and anions with an angle between their mean planes of only 4.35 (11)°, while in the acetonitrile solvate the cations and anions are nearly perpendicular to one another (86.1° between mean planes). The crystal showed partial inversion twinning

The synthesis of potential antimalarials. Derivatives of pantoyltaurine

The general hypothesis as to the mode of action of chemotherapeutic agents, which has been formulated by Fildes, Woods, McIlwain, and others (2), offers a rational and useful guide to the design of new drugs. Thus, bacteriostasis is pictured as caused by the blocking of reactions essential to growth by an inhibiting substance which has a structure similar to that of one of the normal enzymes or metabolites essential to the growth of the organism

catena-Poly[[[diaqua­(nitrato-κ2 O,O′)(2,2′:6′,2′′-terpyridine-κ3 N,N′,N′′)neodymium(III)]-μ-cyanido-κ2 N:C-[dicyanidoplatinum(II)]-μ-cyanido-κ2 C:N] acetonitrile solvate 2,2′:6′,2′′-terpyridine hemisolvate]

The title compound, {[NdPt(CN)4(NO3)(C15H11N3)(H2O)2]·CH3CN·0.5C15H11N3}n, was isolated from solution as a one-dimensional coordination polymer. The Nd3+ site in the structure has a ninefold coordination with a distorted tricapped trigonal-prismatic geometry, while the PtII ion is coordinated by four cyanide groups in an almost regular square-planar geometry. Cis-bridging by the tetracyanidoplatinate anions links the Nd3+ cations, forming the one-dimensional chains. Additionally, each Nd3+ contains coordin­ation by two water mol­ecules, one tridentate 2,2′:6′,2′′-terpyridine mol­ecule, and one bidentate nitrate anion. 2,2′:6′,2′′-Terpyridine and acetonitrile solvent mol­ecules are incorporated between the chains, the former form π-stacking inter­actions (average inter­planar distance 3.33 Å) with terpyridine mol­ecules located in the chains. Relatively long Pt⋯Pt inter­actions [3.847 (1) Å] are observed in the structure. O—H⋯N and O—H⋯O hydrogen bonding interactions between the consituents consolidates the crystal packing

The association of state per capita income and military service deaths in the Vietnam and Iraq wars

<p>Abstract</p> <p>Background</p> <p>In the United States, social burdens including war casualties are often distributed unequally across groups of individuals, communities, and states. The purpose of this report was to examine the association between war deaths and per capita income in the 50 states and District of Columbia during the Vietnam and Iraq wars.</p> <p>Methods</p> <p>The numbers of deaths by the home state of record for each conflict were obtained from Department of Defense records on the Internet as were key variables including age at death, gender, race, branch of service, rank, circumstances of death, home state of record and the ratio of wounded to dead. In addition, we obtained state per capita income and state population for the relevant times.</p> <p>Results</p> <p>Characteristics of decedents in the 2 conflicts were very similar with young, white enlisted men accounting for the majority of deaths. However, in the Iraq war, women accounted for a 2.4% of casualties. Also of note was the higher ratio of wounded to dead in Iraq. At the level of the state, the correlation between the ratio of deaths per 100,000 and per capita income was -0.51 (p < 0.0001) for Vietnam and -0.52 for Iraq (p < 0.0001). In both eras, states with lower per capita income tended to have higher ratios of deaths per population.</p> <p>Conclusion</p> <p>For military service members serving in the Vietnam and Iraq conflicts, there were many more women who died in the latter war. Whether war deaths resulted in lower per capita income cannot be determined from these cross sectional data; we simply note a strong association between per capita income and war casualty rates for both wars.</p

Microwave power transmission system studies. Volume 2: Introduction, organization, environmental and spaceborne systems analyses

Introduction, organization, analyses, conclusions, and recommendations for each of the spaceborne subsystems are presented. Environmental effects - propagation analyses are presented with appendices covering radio wave diffraction by random ionospheric irregularities, self-focusing plasma instabilities and ohmic heating of the D-region. Analyses of dc to rf conversion subsystems and system considerations for both the amplitron and the klystron are included with appendices for the klystron covering cavity circuit calculations, output power of the solenoid-focused klystron, thermal control system, and confined flow focusing of a relativistic beam. The photovoltaic power source characteristics are discussed as they apply to interfacing with the power distribution flow paths, magnetic field interaction, dc to rf converter protection, power distribution including estimates for the power budget, weights, and costs. Analyses for the transmitting antenna consider the aperture illumination and size, with associated efficiencies and ground power distributions. Analyses of subarray types and dimensions, attitude error, flatness, phase error, subarray layout, frequency tolerance, attenuation, waveguide dimensional tolerances, mechanical including thermal considerations are included. Implications associated with transportation, assembly and packaging, attitude control and alignment are discussed. The phase front control subsystem, including both ground based pilot signal driven adaptive and ground command approaches with their associated phase errors, are analyzed

Microwave Power Transmission System Studies. Volume 1: Executive Summary

A study of microwave power generation, transmission, reception and control was conducted as a part of a program to demonstrate the feasibility of power transmission from geosynchronous orbit. A summary is presented of results concerning design approaches, estimated costs (ROM), critical technology, associated ground and orbital test programs with emphasis on dc to rf conversion, transmitting antenna, phase control, mechanical systems, flight operations, ground power receiving-rectifying antenna with systems analysis, and evaluation. Recommendations for early further in-depth studies complementing the technology program are included