The Demographics of the U.S. Equine Population

In this demographic examination of America’s equine population, the numbers clearly show upward trends in all things equestrian over the past fifty years. Will that trajectory continue, adding year after year to the current ten million population, or will loss of open spaces turn the tide as it limits horse housing and riding room? Will ownership patterns undergo fundamental changes when population density, land costs, and escalating environmental controls eliminate the “backyard”- keeping concept and make suburban boarding stables untenable? Will horse production expenses rise in the face of land pressures to the point that equestrian involvement, now a highly egalitarian pursuit in this country, truly becomes a rich person’s game

The Demographics of the U.S. Equine Population

In this demographic examination of America’s equine population, the numbers clearly show upward trends in all things equestrian over the past fifty years. Will that trajectory continue, adding year after year to the current ten million population, or will loss of open spaces turn the tide as it limits horse housing and riding room? Will ownership patterns undergo fundamental changes when population density, land costs, and escalating environmental controls eliminate the “backyard”- keeping concept and make suburban boarding stables untenable? Will horse production expenses rise in the face of land pressures to the point that equestrian involvement, now a highly egalitarian pursuit in this country, truly becomes a rich person’s game

A Modified Single Defect Cavity Study for Coherent Coupling in Photonic Crystal VCSELs

A modified single defect cavity study was conducted to determine if a calibrated simplified model could be use to predict and subsequently design for coherent coupling in PhC VCSELs. Modeled and fabricated devices are compared

The Single-Angle Plane-Wave Spectral Response of One-Dimensional Photonic Crystal Structures

The multiple-incident-angle transmittances or reflectances of fabricated 1-D photonic crystal (PC) structures are measured. Regularization methods are applied to these measurements to determine the single-angle plane-wave spectral response of the structure

Determining the Solution Space of Vertex-Cover by Interactions and Backbones

To solve the combinatorial optimization problems especially the minimal Vertex-cover problem with high efficiency, is a significant task in theoretical computer science and many other subjects. Aiming at detecting the solution space of Vertex-cover, a new structure named interaction between nodes is defined and discovered for random graph, which results in the emergence of the frustration and long-range correlation phenomenon. Based on the backbones and interactions with a node adding process, we propose an Interaction and Backbone Evolution Algorithm to achieve the reduced solution graph, which has a direct correspondence to the solution space of Vertex-cover. By this algorithm, the whole solution space can be obtained strictly when there is no leaf-removal core on the graph and the odd cycles of unfrozen nodes bring great obstacles to its efficiency. Besides, this algorithm possesses favorable exactness and has good performance on random instances even with high average degrees. The interaction with the algorithm provides a new viewpoint to solve Vertex-cover, which will have a wide range of applications to different types of graphs, better usage of which can lower the computational complexity for solving Vertex-cover

First trimester ultrasound measurements and maternal serum biomarkers as prognostic factors in monochorionic twins: a cohort study

Background: Monochorionic twin pregnancies are high-risk of adverse outcomes, but it is not possible to predict which pregnancies will develop complications. The aim of the study was to evaluate, in monochorionic twin pregnancies, whether first trimester ultrasound (nuchal translucency [NT], crown-rump length [CRL]) and maternal serum biomarkers (alpha-fetoprotein (AFP), soluble fms-like tyrosine kinase-1 (sFlt-1), placental growth factor (PlGF)) are prognostic factors for fetal adverse outcome composite, twin-twin transfusion syndrome (TTTS), growth restriction, and intrauterine fetal death (IUFD). Methods: Cohort study of 177 monochorionic diamniotic twin pregnancies. Independent prognostic ability of each factor was assessed by multivariable logistic regression, adjusting for standard prognostic factors. Factors were analysed as continuous data, thus the reported ORs relate either 1% change in NT or CRL inter-twin percentage discordance, or one unit of measure in each serum biomarker. Results: The odds of the fetal adverse outcome composite was significantly associated with increased NT inter-twin percentage discordance (adjusted OR 1.03 [95%CI 1.01,1.06]), and CRL inter-twin percentage discordance (adjusted OR 1.17 [95%CI 1.07,1.29]). TTTS was significantly associated with increased NT discordance (adjusted OR 1.06 [95%CI 1.03,1.10]), and decreased PlGF (adjusted OR 0.42 [95%CI 0.19,0.93]). Antenatal growth restriction was significantly associated with increased CRL discordance (adjusted OR 1.20 [95%CI 1.08,1.34]). Single and double IUFD were associated with decreased PlGF (adjusted OR 0.34 [95%CI 0.12,0.98]) and (adjusted OR 0.18 [95%CI 0.05,0.58]) respectively. Conclusion(s): This study has identified potential individual prognostic factors in the first trimester (fetal biometric and maternal serum biomarkers) that show promise but require further robust evaluation in a larger, prospective series of MC twin pregnancies, so that their usefulness both individually and in combination can be defined. Trial registration: ISRCTN 13114861 (retrospectively registered