Intense Source of Slow Positrons

We describe a novel design for an intense source of slow positrons based on pair production with a beam of electrons from a 10 MeV accelerator hitting a thin target at a low incidence angle. The positrons are collected with a set of coils adapted to the large production angle. The collection system is designed to inject the positrons in a Greaves-Surko trap [1]. Such a source could be the basis for a series of experiments in fundamental and applied research and would also be a prototype source for industrial applications which concern the field of defect characterization in the nanometer scale.Comment: submitted to N.I.M.

Insulin-like growth factor II acts through an endogenous growth pathway regulated by imprinting in early mouse embryos

We present evidence that insulin-like growth factor II (IGF-II) mediates growth in early mouse embryos and forms a pathway in which imprinted genes influence development during preimplantation stages, mRNA and protein for IGF-II were expressed in preimplantation mouse embryos, but the related factors IGF-I and insulin were not. IGF-I and insulin receptors and the IGF-II/mannose-6-phosphate receptor were expressed. Exogenous IGF-II or IGF-I increased the cell number in cultured blastocysts, but a mutant form of IGF-II that strongly binds only the IGF-II receptor did not. Reduction of IGF-II expression by antisense IGF-II oligonucleotides decreased the rate of progression to the blastocyst stage and decreased the cell number in blastocysts. Preimplantation parthenogenetic mouse embryos expressed mRNA for the IGF-II receptor but not for either IGF-II ligand or the IGF-I receptor, indicating that the latter genes are not expressed when inherited maternally. These data imply that some growth factors and receptors, regulated by genomic imprinting, may control cell proliferation from the earliest stages of embryonic development

Two alkaline phosphatase genes are expressed during early development in the mouse embryo

Alkaline phosphatase (AP) activity is stage specific in mouse embryos and may be associated with compaction and separation of trophectoderm from inner cell mass in preimplantation development. We previously sequenced a cDNA and two mouse AP genes that could contribute to the AP activity in embryos. Oligonucleotide primers were constructed from the three sequences and used in the reverse transcription-polymerase chain reaction technique to establish that two of the three AP isozymes are transcribed during preimplantation development. The predominant transcript (E-AP) is from a gene highly homologous to the human tissue-specific APs, but different from the mouse intestinal AP. Tissue non- specific (TN) AP also is transcribed, but there is approximately 10 times less TN-AP than E-AP tran- script. The TN-AP isozyme is the predominant tran- script of 7 to 14 day embryos and primordial germ cells. A switch in predominance from E-AP to TN-AP must occur during early postimplantation development. This study establishes a framework for experiments to determine the functions of the two isozymes during preimplantation development

Methane Flux in Cropland and Adjacent Riparian Buff ers with Different Vegetation Covers

While water quality functions of conservation buffers established adjacent to cropped fields have been widely documented, the relative contribution of these re-established perennial plant systems to greenhouse gases has not been completely documented. In the case of methane (CH(4)), these systems have the potential to serve as sinks of CH(4) or may provide favorable conditions for CH(4) production. This study quantifies CH(4) flux from soils of riparian buffer systems comprised of three vegetation types and compares these fluxes with those of adjacent crop fields. We measured soil properties and diel and seasonal variations of CH(4) flux in 7 to 17 yr-old re-established riparian forest buffers, warm-season and cool-season grass filters, and an adjacent crop field located in the Bear Creek watershed in central Iowa. Forest buffer and grass filter soils had significantly lower bulk density (P \u3c 0.01); and higher pH (P \u3c 0.01), total carbon (TC) (P \u3c 0.01), and total nitrogen (TN) (P \u3c 0.01) than crop field soils. There was no significant relationship between CH(4) flux and soil moisture or soil temperature among sites within the range of conditions observed. Cumulative CH(4) flux was -0.80 kg CH(4)-C ha(-1) yr(-1) in the cropped field, -0.46 kg CH(4)-C ha(-1) yr(-1) within the forest buffers, and 0.04 kg CH(4)-C ha(-1) yr(-1) within grass filters, but difference among vegetation covers was not significant. Results suggest that CH(4) flux was not changed after establishment of perennial vegetation on cropped soils, despite significant changes in soil properties

Preserving the Royalty-Free Standards Ecosystem

It has long been recognized in Europe and elsewhere that standards-development organizations (SDOs) may adopt policies that require their participants to license patents essential to the SDO’s standards (standards-essential patents or SEPs) to manufacturers of standardized products (“implementers”) on a royalty-free (RF) basis.1 This requirement contrasts with SDO policies that permit SEP holders to charge implementers monetary patent royalties, sometimes on terms that are specified as “fair, reasonable and nondiscriminatory” (FRAND). As demonstrated by two decades of intensive litigation around the world, FRAND royalties have given rise to intractable disputes regarding the manner in which such royalties should be calculated and adjudicated. In contrast, standards distributed on an RF basis are comparatively free from litigation and the attendant transaction costs.2 Accordingly, numerous SDOs around the world have adopted RF licensing policies and many widely adopted standards, including Bluetooth, USB, IPv6, HTTP, HTML and XML, are distributed on an RF basis. This note briefly discusses the commercial considerations surrounding RF standards, the relationship between RF standards and open source software (OSS) and the SDO policy mechanisms – including “universal reciprocity” -- that enable RF licensing to succeed in the marketplace

Rand Patents and Exclusion Orders: Submission of 19 Economics and Law Professors to the International Trade Commission

In this comment to ITC Investigation 337-TA-745 (Certain Wireless Communication Devices, Motorola v. Apple) we, as teachers and scholars of economics, antitrust and intellectual property, remedies, administrative, and international intellectual property law, former Department of Justice lawyers and chief economists, a former executive official at the Patent and Trademark Office, a former counsel at the ITC Office of the General Counsel, and a former Member of the President’s Council of Economic Adviser take the position that ITC exclusion orders generally should not be granted under § 1337(d)(1) on the basis of patents subject to obligations to license on “reasonable and non-discriminatory” (RAND) terms. Doing so would undermine the significant pro-competitive and pro-consumer benefits that RAND promises produce and the investments they enable. A possible exception may arise if district court jurisdiction is lacking, the patent is valid and infringed, and the public interest favors issuing an exclusion order. We explain our position in the comment

Human Processing of Behaviorally Relevant and Irrelevant Absence of Expected Rewards: A High-Resolution ERP Study

Acute lesions of the posterior medial orbitofrontal cortex (OFC) in humans may induce a state of reality confusion marked by confabulation, disorientation, and currently inappropriate actions. This clinical state is strongly associated with an inability to abandon previously valid anticipations, that is, extinction capacity. In healthy subjects, the filtering of memories according to their relation with ongoing reality is associated with activity in posterior medial OFC (area 13) and electrophysiologically expressed at 220–300 ms. These observations indicate that the human OFC also functions as a generic reality monitoring system. For this function, it is presumably more important for the OFC to evaluate the current behavioral appropriateness of anticipations rather than their hedonic value. In the present study, we put this hypothesis to the test. Participants performed a reversal learning task with intermittent absence of reward delivery. High-density evoked potential analysis showed that the omission of expected reward induced a specific electrocortical response in trials signaling the necessity to abandon the hitherto reward predicting choice, but not when omission of reward had no such connotation. This processing difference occurred at 200–300 ms. Source estimation using inverse solution analysis indicated that it emanated from the posterior medial OFC. We suggest that the human brain uses this signal from the OFC to keep thought and behavior in phase with reality

Single hadron response measurement and calorimeter jet energy scale uncertainty with the ATLAS detector at the LHC

The uncertainty on the calorimeter energy response to jets of particles is derived for the ATLAS experiment at the Large Hadron Collider (LHC). First, the calorimeter response to single isolated charged hadrons is measured and compared to the Monte Carlo simulation using proton-proton collisions at centre-of-mass energies of sqrt(s) = 900 GeV and 7 TeV collected during 2009 and 2010. Then, using the decay of K_s and Lambda particles, the calorimeter response to specific types of particles (positively and negatively charged pions, protons, and anti-protons) is measured and compared to the Monte Carlo predictions. Finally, the jet energy scale uncertainty is determined by propagating the response uncertainty for single charged and neutral particles to jets. The response uncertainty is 2-5% for central isolated hadrons and 1-3% for the final calorimeter jet energy scale.Comment: 24 pages plus author list (36 pages total), 23 figures, 1 table, submitted to European Physical Journal