(1173) Anchises - Thermophysical and Dynamical Studies of a Dynamically Unstable Jovian Trojan

We have performed detailed thermophysical and dynamical modelling of Jovian Trojan (1173) Anchises. Our results reveal a most unusual object. By examining observational data taken by IRAS, Akari and WISE between 11.5 and 60 microns, along with variations in its optical lightcurve, we find Anchises is most likely an elongated body, with an axes-ratio of ~1.4. This yields calculated best-fit dimensions of 170x121x121km (an equivalent diameter of 136+18/-11km). We find the observations are best fit by Anchises having a retrograde sense of rotation, and an unusually high thermal inertia (25 to 100 Jm-2s-0.5K-1). The geometric albedo is found to be 0.027 (+0.006/-0.007). Anchises therefore has one of the highest published thermal inertias of any object larger than 100km in diameter, at such large heliocentric distances, and is one of the lowest albedo objects ever observed. More observations are needed to see if there is a link between the very shallow phase curve, with almost no opposition effect, and the derived thermal properties for this large Trojan asteroid. Our dynamical investigation of Anchises' orbit has revealed it to be dynamically unstable on timescales of hundreds of Myr, similar to the unstable Neptunian Trojans 2001 QR322 and 2008 LC18. Unlike those objects, we find that Anchises' dynamical stability is not a function of its initial orbital elements, the result of the exceptional precision with which its orbit is known. This is the first time that a Jovian Trojan has been shown to be dynamically unstable, and adds weight to the idea that planetary Trojans represent a significant ongoing contribution to the Centaur population, the parents of the short-period comets. The observed instability does not rule out a primordial origin for Anchises, but when taken in concert with the result of our thermophysical analysis, suggest that it would be a fascinating target for future study.Comment: 5 figures, 3 tables, accepted for publication in Monthly Notices of the Royal Astronomical Societ

A Detailed Investigation of the Proposed NN Serpentis Planetary System

The post-main sequence eclipsing binary NN Serpentis was recently announced as the potential host of at least two massive planetary companions. In that work, the authors put forward two potential architectures that fit the observations of the eclipsing binary with almost identical precision. In this work, we present the results of a dynamical investigation of the orbital stability of both proposed system architectures, finding that they are only stable for scenarios in which the planets are locked in mutual mean motion resonance. In the discovery work, the authors artificially fixed the orbital eccentricity of the more massive planet, NN Ser(AB) c, at 0. Here, we reanalyse the observational data on NN Serpentis without this artificial constraint, and derive a new orbital solution for the two proposed planets. We detail the results of further dynamical simulations investigating the stability of our new orbital solution, and find that allowing a small non-zero eccentricity for the outer planet renders the system unstable. We conclude that, although the original orbits proposed for the NN Serpentis planetary system prove dynamically feasible, further observations of the system are vital in order to better constrain the system's true architecture.Comment: Accepted for publication in Monthly Notices of the Royal Astronomical Society; 5 figures, 2 table

Mediation, arbitration and negotiation

We compare three common dispute resolution processes { negotiation, mediation, and arbitration { in the framework of Crawford and Sobel (1982). Under negotiation, the two parties engage in (possibly arbitrarily long) face-to-face cheap talk. Under mediation, the parties communicate with a neutral third party who makes a non-binding recommendation. Under arbitration, the two parties commit to conform to the third party recommendation. We characterize and compare the optimal mediation and arbitration procedures. Both mediators and arbitrators should optimally filter information, but mediators should also add noise to it. We find that unmediated negotiation performs as well as mediation if and only if the degree of conflict between the parties is low

Genetics and cytology of a genic male-sterile, female-sterile mutant from a transposon-containing soybean population

A male-sterile, female-sterile soybean mutant (w4-m sterile) was identified among progeny of germinal revertants of a gene-tagging study. Our objectives were to determine the genetics (inheritance, allelism, and linkage) and the cytology (microsporogenesis and microgametogenesis) of the w4-m sterile. The mutant was inherited as a single recessive nuclear gene and was nonallelic to known male-sterile, female-sterile mutants st2 st2, st3 st3, st4 st4, st5 st5, and st6 st6 st7 st7. No linkage was detected between the w4-m sterile and the w4w4, y10 y10, y11 y11, y20 y20, fr1 fr1, and fr2 fr2 mutants. Homologous chromosome pairing was complete in fertile plants. Chromosome pairing, as observed in squash preparation, was almost completely absent in sterile plants. Developmentally microsporogenesis proceeded normally in both the fertile and the w4-msterile through the early microspore stage. Then the tapetal cells of thew4-m sterile surrounding the young microspores developed different-size vacuoles. These tapetal cells became smaller in size and separated from each other. Some of the microspores of the w4-m sterile also became more vacuolate prematurely and sometimes they collapsed, usually by the late microspore stage. In the w4-m sterile the microspore walls remained thinner and structurally different from the microspore walls of fertile plants. No pollen was formed in the mutant plants, even though some of the male cells reached the pollen stage, although without normal filling. The w4-m sterile was designated st8st8 and assigned Soybean Genetic Type Collection number T352

Some investigations of refractory metal systems of thermionic interest

Investigating interdiffusion of W-Ta, W-Mo, and W-Nb systems in refractory temperature rang

“A Climate Of Lawlessness”: Upholding a Government’s Affirmative Duty to Protect the Environment Using Deshaney’s Special Relationship Exception

The Industrial Revolution introduced an era of exceptional technological advances. However, it also led to rampant environmental pollution and degradation. The proliferation of toxic pollutants in the air, water and soil has led us to the precipice of an unimaginable future; a future defined by climate change. This Note argues for the use of the special relationship exception, affirmed by the Supreme Court in DeShaney v. Winnebago, in environmental litigation in order to uphold governments’ affirmative duty to protect the environment. As federal and state governments have the sole power to regulate environmental pollution and enforce environmental protections, individuals are left completely dependent on governments to provide for the basic necessities of safe and sustainable water, food, and air. Governments have restrained an individual’s liberty to provide for these basic needs; as such, they should be under an obligation to “fill the gap.

Calcium Oxalate Crystals in Developing Seeds of Soybean

Young developing soybean seeds contain relatively large amounts of calcium oxalate (CaOx) monohydrate crystals. A test for Ca and CaOx indicated that Ca deposits and crystals initially occurred in the funiculus, where a single vascular bundle enters the seed. Crystals formed in the integuments until the embryo enlarged enough to crush the inner portion of the inner integument. Crystals then appeared in the developing cotyledon tissues and embryo axis. All crystals formed in cell vacuoles. Dense bodies and membrane complexes were evident in the funiculus. In the inner integument, cell vacuoles assumed the shape of the future crystals. This presumed predetermined crystal mould is reported here for the first time for soybean seeds. As crystals in each tissue near maturity, a wall forms around each crystal. This intracellular crystal wall becomes contiguous with the cell wall. Integument crystals remain visible until the enlarging embryo crushes the integuments; the crystals then disappear. A related study revealed that the highest percent of oxalate by dry mass was reached in the developing +16 d (post-fertilization) seeds, and then decreased during late seed maturation. At +60 d, CaOx formation and disappearance are an integral part of developing soybean seeds. Our results suggest that Ca deposits and crystals functionally serve as Ca storage for the rapidly enlarging embryos. The oxalate, derived from one or more possible metabolic pathways, could be involved in seed storage protein synthesis

Multicellular Secretory Trichome Development on Soybean and Related Glycine Gynoecia

Multicellular glandular trichomes form on gynoecia of wild annual Glycine species, annual soybean cultivars, and wild perennial Glycine species. These trichomes occur from the ovary base to the style base and, in perennial species, along the style as well.Trichomes form at least 2 d before anthesis, and new trichomes develop throughout flowering and also on young seed pods. Trichome structure is similar in all taxa examined, usually five to seven linearly arranged cells. Stalk cells with callose walls become highly vacuolate, and their cytoplasms have reduced numbers of Golgi bodies and endoplasmic reticulum. During secretion, two to four distal cells develop dense cytoplasms containing both prominent Golgi bodies with large vesicles and endoplasmic reticulum with enlarged lumens. Both organelles are involved in forming carbohydrate/protein secretory products. Internal secretion begins with products exuding between the plasmalemma and the primary wall of each distal cell. Secretion progresses between the primary wall and the outermost cuticle that entirely covers the trichome, which is thicker and more highly modified than a normal cuticle. This cuticle separates from cell walls in secretion regions. Products are exuded outside, occur on the inner surface of trichome and gynoecium, and are more obvious in perennial than in annual taxa. The composition and function of products are unknown

Active damping of a flexible beam

The development of an algorithm that will determine actuator and sensor locations on a flexible beam is discussed. Large space structures will have many locations where actuators can be placed. This research seeks to determine the optimum locations. In addition, the best locations are determined while certain constraints are satisfied which guarantee that mission performance requirements are achieved. The approach adopted is to consider actuators and sensors to be collocated so as to produce an equivalent viscous damper. Ultimately, the experimental results of measuring the log decrement during free decay will correlate with the analytical predictions

COFS 1 research overview

The Control of Flexible Structures (COFS) program is divided into three areas of research. These three areas are controls/structures analysis development, ground test experiments, and in-space experiments. The ground test experiments are intended to validate analyses and to confirm through hardware tests our technical readiness to successfully fly the Mast hardware. There is this close relation to the results of ground tests and analytical predictions that must be understood before flight experiments may be attempted. Details relative to each program area are given