4,764 research outputs found
Patents 101: Patentable Subject Matter and Separation of Powers
The definition of statutory subject matter lies at the heart of the patent system. It is the reflection of Congress\u27s policy decision as to what types of inventions one may patent. While the congressional definition of statutory subject matter (in what is now 35 U.S.C. § 101) has remained fundamentally constant since 1790, the Supreme Court has reinterpreted and redefined statutory subject matter several times, leaving lower courts with the frustrating task of trying to develop a coherent jurisprudence against a changing landscape. This inconstancy has introduced uncertainty for inventors who are trying to make the fundamental decision of whether to maintain a trade secretor seek patent protection for an innovation. Notwithstanding repeated admonitions to the lower courts not to read words into the patent statute, the Supreme Court itself has created three exceptions to the categories of statutory subject matter established by the clear words of § 101: laws of nature, physical phenomena, and abstract ideas. This intervention would be defensible if it were constitutionally required or if the statutory language were ambiguous, but neither is the case. In fact, the Court\u27s particular intervention is counter to the constitutional mandate to promote progress. In certain cases, this disincentive maybe sufficient to prevent promising new technologies from ever developing. This Article proposes that Congress should consider the judicially created exceptions to the statutory categories of patentable subject matter and amend the statute so as to end judicial intrusion into patent policymaking
The Reionization of Carbon
Observations suggest that CII was more abundant than CIV in the intergalactic
medium towards the end of the hydrogen reionization epoch. This transition
provides a unique opportunity to study the enrichment history of intergalactic
gas and the growth of the ionizing background (UVB) at early times. We study
how carbon absorption evolves from z=10-5 using a cosmological hydrodynamic
simulation that includes a self-consistent multifrequency UVB as well as a
well-constrained model for galactic outflows to disperse metals. Our predicted
UVB is within 2-4 times that of Haardt & Madau (2012), which is fair agreement
given the uncertainties. Nonetheless, we use a calibration in post-processing
to account for Lyman-alpha forest measurements while preserving the predicted
spectral slope and inhomogeneity. The UVB fluctuates spatially in such a way
that it always exceeds the volume average in regions where metals are found.
This implies both that a spatially-uniform UVB is a poor approximation and that
metal absorption is not sensitive to the epoch when HII regions overlap
globally even at column densites of 10^{12} cm^{-2}. We find, consistent with
observations, that the CII mass fraction drops to low redshift while CIV rises
owing the combined effects of a growing UVB and continued addition of carbon in
low-density regions. This is mimicked in absorption statistics, which broadly
agree with observations at z=6-3 while predicting that the absorber column
density distributions rise steeply to the lowest observable columns. Our model
reproduces the large observed scatter in the number of low-ionization absorbers
per sightline, implying that the scatter does not indicate a partially-neutral
Universe at z=6.Comment: 16 pages, 14 figures, accepted to MNRA
Direct Detection of Galactic Halo Dark Matter
The Milky Way Galaxy contains a large, spherical component which is believed
to harbor a substantial amount of unseen matter. Recent observations indirectly
suggest that as much as half of this ``dark matter'' may be in the form of old,
very cool white dwarfs, the remnants of an ancient population of stars as old
as the Galaxy itself. We conducted a survey to find faint, cool white dwarfs
with large space velocities, indicative of their membership in the Galaxy's
spherical halo component. The survey reveals a substantial, directly observed
population of old white dwarfs, too faint to be seen in previous surveys. This
newly discovered population accounts for at least 2% of the halo dark matter.
It provides a natural explanation for the indirect observations, and represents
a direct detection of Galactic halo dark matter.Comment: 13 pages, 4 figures, 1 table. Note added after Science Express online
publication: This text reflects the correction of a few typographical errors
in the online version of the table. It also includes the new constraint on
the calculation of d_max which accounts for the fact that the survey could
not have detected stars with proper motions below 0.33 arcseconds per year.
Published online at ScienceExpress www.sciencemag.org 22 March 2001;
10.1126/science.1059954; To appear in Science 27 April 200
Atmospheric, Evolutionary, and Spectral Models of the Brown Dwarf Gliese 229 B
Theoretical spectra and evolutionary models that span the giant planet--brown
dwarf continuum have been computed based on the recent discovery of the brown
dwarf, Gliese 229 B. A flux enhancement in the 4--5 micron window is a
universal feature from Jovian planets to brown dwarfs. We confirm the existence
of methane and water in Gl 229 B's spectrum and find its mass to be 30 to 55
Jovian masses. Although these calculations focus on Gliese 229 B, they are also
meant to guide future searches for extra-solar giant planets and brown dwarfs.Comment: 8 pages, plain TeX, plus four postscript figures, gzipped and
uuencoded, accepted for Scienc
Sulfur Degassing From Volcanoes: Source Conditions, Surveillance, Plume Chemistry and Earth System Impacts
International audienceDespite its relatively minor abundance in magmas (compared with H2O and CO2), sulfur degassing from volcanoes is of tremendous significance. It can exert substantial influence on magmatic evolution (potentially capable of triggering eruptions); represents one of the most convenient opportunities for volcano monitoring and hazard assessment; and can result in major impacts on the atmosphere, climate and terrestrial ecosystems at a range of spatial and temporal scales. The complex behavior of sulfur in magmas owes much to its multiple valence states (-II, 0, IV, VI), speciation (e.g., S2, H2S, SO2, OCS and SO3 in the gas phase; S2-, SO42- and SO32- in the melt; and non-volatile solid phases such as pyrrhotite and anhydrite), and variation in stable isotopic composition (32S, 33S, 34S and 36S; e.g., MĂ©trich and Mandeville 2010). Sulfur chemistry in the atmosphere is similarly rich involving gaseous and condensed phases and invoking complex homogeneous and heterogeneous chemical reactions. Sulfur degassing from volcanoes and geothermal areas is also important since a variety of microorganisms thrive based on the redox chemistry of sulfur: by reducing sulfur, thiosulfate, sulfite and sulfate to H2S, or oxidizing sulfur and H2S to sulfate (e.g., Takano et al. 1997; Amend and Shock 2001; Shock et al. 2010). Understanding volcanic sulfur degassing thus provides vital insights into magmatic, volcanic and hydrothermal processes; the impacts of volcanism on the Earth system; and biogeochemical cycles. Here, we review the causes of variability in sulfur abundance and speciation in different geodynamic contexts; the measurement of sulfur emissions from volcanoes; links between subsurface processes and surface observations; sulfur chemistry in volcanic plumes; and the consequences of sulfur degassing for climate and the environment
Exploiting ground-based optical sensing technologies for volcanic gas surveillance
Measurements of volcanic gas composition and flux are crucial to probing and understanding a range of magmatic,
hydrothermal and atmospheric interactions. The value of optical remote sensing methods has been recognised in this field for more than thirty years but several recent developments promise a new era of volcanic gas surveillance. This could see much higher time- and space-resolved data-sets, sustained at individual volcanoes
even during eruptive episodes. We provide here an overview of these optical methods and their application to ground-based volcano monitoring, covering passive and active measurements in the ultraviolet and infrared spectral regions. We hope thereby to promote the use of such devices, and to stimulate development of new optical
techniques for volcanological research and monitoring
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