Review and Reply: On “Why America’s Army Can’t Win America’s Wars” (part 2)

This commentary responds to John A. Nagl’s article, “Why America’s Army Can’t Win America’s Wars,” published in the Autumn 2022 issue of Parameters (vol. 52, no. 3)

Regiospecific Synthesis and X-ray Structural Study of Trifluoromethyl Substituted Dibenzosemibullvalene

Preparation of the novel regiospecifically trifluoromethyl substituted dibenzobarrelene 5 and dibenzosemibullvalene 6 is described. Unequivocal proof for the stereostructure of 6 was obtained by its X-ray crystallographic analysis. Geometrical data from X-ray structural analysis showed that the ester carbonyl groups adopt unfavorable conformations for conjugative interactions with respect to the cyclopropane ring involved in the skeleton of 6

Diastereoisomerization and X-ray Crystal Structure of meso-di-(2H-Chromene-2-yl) Ether

It was shown by X-ray crystal structure analysis that di-(2Hchromene- 2-yl)-ether (1) exists in the meso-form, i.e. as (2S, 2\u27R)-1. The Xray structural data indicate, also, that geometries of the two 2H-1-benzopyran parts, of which the skeleton of 1 consists, are not identical, that is the molecule is pseudosymmetrical. The meso-l undergoes thermally induced electrocyclic ring opening and reclosure. Thus, meso-1 equilibrates with enantiomers (2S, 2\u27S)-1 and (2R, 2\u27R)-1, as conf\u27irmed by their lH_ NMR spectra after preparative separation of stereoisomers using liquid chromatography on triacetylcellulose

Effects of anharmonic strain on phase stability of epitaxial films and superlattices: applications to noble metals

Epitaxial strain energies of epitaxial films and bulk superlattices are studied via first-principles total energy calculations using the local-density approximation. Anharmonic effects due to large lattice mismatch, beyond the reach of the harmonic elasticity theory, are found to be very important in Cu/Au (lattice mismatch 12%), Cu/Ag (12%) and Ni/Au (15%). We find that is the elastically soft direction for biaxial expansion of Cu and Ni, but it is for large biaxial compression of Cu, Ag, and Au. The stability of superlattices is discussed in terms of the coherency strain and interfacial energies. We find that in phase-separating systems such as Cu-Ag the superlattice formation energies decrease with superlattice period, and the interfacial energy is positive. Superlattices are formed easiest on (001) and hardest on (111) substrates. For ordering systems, such as Cu-Au and Ag-Au, the formation energy of superlattices increases with period, and interfacial energies are negative. These superlattices are formed easiest on (001) or (110) and hardest on (111) substrates. For Ni-Au we find a hybrid behavior: superlattices along and like in phase-separating systems, while for they behave like in ordering systems. Finally, recent experimental results on epitaxial stabilization of disordered Ni-Au and Cu-Ag alloys, immiscible in the bulk form, are explained in terms of destabilization of the phase separated state due to lattice mismatch between the substrate and constituents.Comment: RevTeX galley format, 16 pages, includes 9 EPS figures, to appear in Physical Review

Resonances and Surface Waves in Elastic Wave Scattering from Cavities and Inclusions

Elastic-wave scattering from various types of cavities and inclusions has been studied theoretically with special emphasis on surface wave effects that appear during the scattering process. Resonances in the scattering amplitudes are caused by the phase matching of circumnavigating surface waves, and manifest themselves as poles in the complex frequency plane that correspond to the (complex) eigenfrequencies of the cavity of inclusion. These results are most easily obtained for scatterers of separable geometry, such as spheres, where theoretical amplitudes are well-known. Here, the formalism for a complete treatment of elastic-wave scattering from infinite cylindrical cavities and solid inclusions has been worked out for general oblique incidence. Poles of scattering amplitudes have been found for evacuated and for fluid-filled cylinders, and have been physically interpreted in terms of helical surface waves propagating both interior and exterior to the cylinder. Dispersion, attenuation, and refraction of these surface waves have been obtained. Progressing to more generally-shaped obstacles, we have studied surface waves and complex-frequency poles for finite- length cylindrical cavities with flat ends. In this fashion, the resonance features(particularly the cavity eigenfrequencies) that appear prominently in the scattering amplitude can be understood as to their physical origin and their dependence on the type of cavity, and may be exploited for purposes of classification and identification of flaws by their ultrasonic resonances (ultrasonic “resonance spectroscopy”)

The transition to parenthood following a history of childhood maltreatment: a review of the literature on prospective and new parents' experiences

Background: Becoming a parent is viewed as one of the most important transitions in one’s life. However, a history of childhood maltreatment may affect the adjustment to parenthood. Objective: The objective of this review was to synthesize the current evidence base to further our understanding of prospective and new parents’ experiences in the transition to parenthood (pregnancy to 2 years post-birth), in the context of having a childhood maltreatment history. Method: A scoping review of the literature was conducted using the following online databases: PubMed, PsycINFO, PsycNET, and Published International Literature of Traumatic Stress. Results: The findings were synthesized into a four-component theoretical framework, which included mental health of the parent, physical changes, parental view of the child, and view of the self as a parent. A total of 69 papers, including 181,537 participants (of whom 30,482 mothers and 235 fathers had maltreatment histories), investigated the transition to parenthood. The majority of the studies showed that parents with a maltreatment history may suffer from a range of mental health problems during the transition to parenthood, experience more negative physical changes, and have more negative views of their child (or children). However, they reported both positive and negative experiences regarding their identity as a parent. Conclusions: The findings suggest that maltreatment is a risk factor for a more challenging transition to parenthood. Experiences of fathers with maltreatment histories merit more attention, as do those of parents in low- and middle-income countries. Future directions should include predictors of positive experiences and the development of early interventions to improve outcomes for this population

Longitudinal Bunch Shape Diagnostics With Coherent Radiation And a Transverse Deflecting Cavity at TTF2

At the DESY TTF2 linear accelerator three special techniques to characterize the longitudinal charge distribution of the electron bunches that drive the free-electron laser are currently under study: electro-optical sampling, far-infrared spectral analysis of coherent radiation and the use of a transverse deflecting cavity to streak the bunch. The principles and implementations of the latter two are described in this paper. Details on electro-optical sampling can be found in [1]

Parent-of-origin-specific allelic associations among 106 genomic loci for age at menarche.

Age at menarche is a marker of timing of puberty in females. It varies widely between individuals, is a heritable trait and is associated with risks for obesity, type 2 diabetes, cardiovascular disease, breast cancer and all-cause mortality. Studies of rare human disorders of puberty and animal models point to a complex hypothalamic-pituitary-hormonal regulation, but the mechanisms that determine pubertal timing and underlie its links to disease risk remain unclear. Here, using genome-wide and custom-genotyping arrays in up to 182,416 women of European descent from 57 studies, we found robust evidence (P < 5 × 10(-8)) for 123 signals at 106 genomic loci associated with age at menarche. Many loci were associated with other pubertal traits in both sexes, and there was substantial overlap with genes implicated in body mass index and various diseases, including rare disorders of puberty. Menarche signals were enriched in imprinted regions, with three loci (DLK1-WDR25, MKRN3-MAGEL2 and KCNK9) demonstrating parent-of-origin-specific associations concordant with known parental expression patterns. Pathway analyses implicated nuclear hormone receptors, particularly retinoic acid and γ-aminobutyric acid-B2 receptor signalling, among novel mechanisms that regulate pubertal timing in humans. Our findings suggest a genetic architecture involving at least hundreds of common variants in the coordinated timing of the pubertal transition

Regional integration of long-term national dense GNSS network solutions

The EUREF Permanent Network Densification is a collaborative effort of 26 European GNSS analysis centers providing series of daily or weekly station position estimates of dense national and regional GNSS networks, in order to combine them into one homogenized set of station positions and velocities. During the combination, the station meta-data, including station names, DOMES numbers, and position offset definitions were carefully homogenized, position outliers were efficiently eliminated, and the results were cross-checked for any remaining inconsistencies. The results cover the period from March 1999 to January 2017 (GPS week 1000-1933) and include 31 networks with positions and velocities for 3192 stations, well covering Europe. The positions and velocities are expressed in ITRF2014 and ETRF2014 reference frames based on the Minimum Constraint approach using a selected set of ITRF2014 reference stations. The position alignment with the ITRF2014 is at the level of 1.5, 1.2, and 3.2\ua0mm RMS for the East, North, Up components, respectively, while the velocity RMS values are 0.17, 0.14, and 0.38\ua0mm/year for the East, North, and Up components, respectively. The high quality of the combined solution is also reflected by the 1.1, 1.1, and 3.5\ua0mm weighted RMS values for the East, North, and Up components, respectively