Worms, Mice, Cows and Pigs: The Importance of Animal Patents in Developing Countries

Transgenic animals play a large role in several critical industries: the pharmaceutical industry, the agricultural industry, farming, and medical research. As these biotechnology-oriented industries have grown, the United States and other industrialized nations have realized the importance of patent protection for genetically-engineered animals. Unfortunately, lesser-developed countries (LDCs), which can benefit the most from such industries, do not provide adequate patent protection for transgenic animals, even though patent protection for transgenic animals could ultimately lead to reduction in starvation and disease, two of the biggest problems facing many LDCs. The United States should pursue bilateral negotiations with developing countries in the area of animal patents to secure patent protection for transgenic animals. Because of their flexibility, bilateral agreements offer a better short-term solution than multilateral agreements. This comment first describes the methods for creating transgenic animals and the importance of these animals. Second, this article outlines the current state of animal patents in industrialized countries and the various controversies those countries have faced during the development of their current policies. Third, this article explains and refutes the arguments advanced by developing countries to support their lack of adequate patent protection for transgenic animals. Finally, this article shows that the best short-term solution to align the views of the industrialized countries with those of the various developing countries are bilateral agreements rather than multilateral agreements

Worms, Mice, Cows and Pigs: The Importance of Animal Patents in Developing Countries

Transgenic animals play a large role in several critical industries: the pharmaceutical industry, the agricultural industry, farming, and medical research. As these biotechnology-oriented industries have grown, the United States and other industrialized nations have realized the importance of patent protection for genetically-engineered animals. Unfortunately, lesser-developed countries (LDCs), which can benefit the most from such industries, do not provide adequate patent protection for transgenic animals, even though patent protection for transgenic animals could ultimately lead to reduction in starvation and disease, two of the biggest problems facing many LDCs. The United States should pursue bilateral negotiations with developing countries in the area of animal patents to secure patent protection for transgenic animals. Because of their flexibility, bilateral agreements offer a better short-term solution than multilateral agreements. This comment first describes the methods for creating transgenic animals and the importance of these animals. Second, this article outlines the current state of animal patents in industrialized countries and the various controversies those countries have faced during the development of their current policies. Third, this article explains and refutes the arguments advanced by developing countries to support their lack of adequate patent protection for transgenic animals. Finally, this article shows that the best short-term solution to align the views of the industrialized countries with those of the various developing countries are bilateral agreements rather than multilateral agreements

Direct observation of minibands in twisted heterobilayers

Stacking two-dimensional (2D) van der Waals materials with different interlayer atomic registry in a heterobilayer causes the formation of a long-range periodic superlattice that may bestow the heterostructure with exotic properties such as new quantum fractal states [1-3] or superconductivity [4, 5]. Recent optical measurements of transition metal dichalcogenide (TMD) heterobilayers have revealed the presence of hybridized interlayer electron-hole pair excitations at energies defined by the superlattice potential [6-10]. The corresponding quasiparticle band structure, so-called minibands, have remained elusive and no such features have been reported for heterobilayers comprised of a TMD and another type of 2D material. Here, we introduce a new X-ray capillary technology for performing micro-focused angle-resolved photoemission spectroscopy (microARPES) with a spatial resolution on the order of 1 $\mu$m, enabling us to map the momentum-dependent quasiparticle dispersion of heterobilayers consisting of graphene on WS$_2$ at variable interlayer twist angles ($\theta$). Minibands are directly observed for $\theta = 2.5^{\circ}$ in multiple mini Brillouin zones (mBZs), while they are absent for a larger twist angle of $\theta = 26.3^{\circ}$. These findings underline the possibility to control quantum states via the stacking configuration in 2D heterostructures, opening multiple new avenues for generating materials with enhanced functionality such as tunable electronic correlations [11] and tailored selection rules for optical transitions [12].Comment: Main manuscript: 14 pages, 4 figures. Supporting information: 8 pages, 5 figure

Search-and-replace editing for personal photo collections

We propose a new system for editing personal photo collections, inspired by search-and-replace editing for text. In our system, local edits specified by the user in a single photo (e.g., using the “clone brush” tool) can be propagated automatically to other photos in the same collection, by matching the edited region across photos. To achieve this, we build on tools from computer vision for image matching. Our experimental results on real photo collections demonstrate the feasibility and potential benefits of our approach.Natural Sciences and Engineering Research Council of Canada Postdoctoral FellowshipMassachusetts Institute of Technology. Undergraduate Research Opportunities ProgramNational Science Foundation (U.S.) (CAREER award 0447561)T-Party ProjectUnited States. National Geospatial-Intelligence Agency (NGA NEGI-1582- 04-0004)United States. Office of Naval Research. Multidisciplinary University Research Initiative (Grant N00014-06-1-0734)Microsoft ResearchAlfred P. Sloan Foundatio

Giant spin-splitting and gap renormalization driven by trions in single-layer WS2_2/h-BN heterostructures

In two-dimensional (2D) semiconducting transition metal dichalcogenides (TMDs), new electronic phenomena such as tunable band gaps and strongly bound excitons and trions emerge from strong many-body effects, beyond spin-orbit coupling- and lattice symmetry-induced spin and valley degrees of freedom. Combining single-layer (SL) TMDs with other 2D materials in van der Waals heterostructures offers an intriguing means of controlling the electronic properties through these many-body effects via engineered interlayer interactions. Here, we employ micro-focused angle-resolved photoemission spectroscopy (microARPES) and in-situ surface doping to manipulate the electronic structure of SL WS$_2$ on hexagonal boron nitride (WS$_2$/h-BN). Upon electron doping, we observe an unexpected giant renormalization of the SL WS$_2$ valence band (VB) spin-orbit splitting from 430~meV to 660~meV, together with a band gap reduction of at least 325~meV, attributed to the formation of trionic quasiparticles. These findings suggest that the electronic, spintronic and excitonic properties are widely tunable in 2D TMD/h-BN heterostructures, as these are intimately linked to the quasiparticle dynamics of the materials.Comment: 14 pages, 4 figures. Address correspondence to [email protected] or [email protected]

Instability of two dimensional graphene: Breaking sp2 bonds with soft X-rays

We study the stability of various kinds of graphene samples under soft X-ray irradiation. Our results show that in single layer exfoliated graphene (a closer analogue to two dimensional material), the in-plane carbon-carbon bonds are unstable under X-ray irradiation, resulting in nanocrystalline structures. As the interaction along the third dimension increases by increasing the number of graphene layers or through the interaction with the substrate (epitaxial graphene), the effect of X-ray irradiation decreases and eventually becomes negligible for graphite and epitaxial graphene. Our results demonstrate the importance of the interaction along the third dimension in stabilizing the long range in-plane carbon-carbon bonding, and suggest the possibility of using X-ray to pattern graphene nanostructures in exfoliated graphene.Comment: 4 pages, 3 figures, Phys. Rev. B rapid communication, in pres

Topological surface states above the Fermi energy in Hf2Te2P\textrm{Hf}_{2}\textrm{Te}_2\textrm{P}

We report a detailed experimental study of the band structure of the recently discovered topological material $\textrm{Hf}_{2}\textrm{Te}_2\textrm{P}$. Using the combination of scanning tunneling spectroscopy and angle-resolved photo-emission spectroscopy with surface K-doping, we probe the band structure of $\textrm{Hf}_{2}\textrm{Te}_2\textrm{P}$ with energy and momentum resolution above the Fermi level. Our experiments show the presence of multiple surface states with a linear Dirac-like dispersion, consistent with the predictions from previously reported band structure calculations. In particular, scanning tunneling spectroscopy measurements provide the first experimental evidence for the strong topological surface state predicted at 460 meV, which stems from the band inversion between Hf-d and Te-p orbitals. This band inversion comprised of more localized d-states could result in a better surface-to-bulk conductance ratio relative to more traditional topological insulators.Comment: Supplementary materials available upon reques

A universal high energy anomaly in angle resolved photoemission spectra of high temperature superconductors - possible evidence of spinon and holon branches

A universal high energy anomaly in the single particle spectral function is reported in three different families of high temperature superconductors by using angle-resolved photoemission spectroscopy. As we follow the dispersing peak of the spectral function from the Fermi energy to the valence band complex, we find dispersion anomalies marked by two distinctive high energy scales, E_1=~ 0.38 eV and E_2=~0.8 eV. E_1 marks the energy above which the dispersion splits into two branches. One is a continuation of the near parabolic dispersion, albeit with reduced spectral weight, and reaches the bottom of the band at the gamma point at ~0.5 eV. The other is given by a peak in the momentum space, nearly independent of energy between E_1 and E_2. Above E_2, a band-like dispersion re-emerges. We conjecture that these two energies mark the disintegration of the low energy quasiparticles into a spinon and holon branch in the high T_c cuprates.Comment: accepted for publication in Phys. Rev. Let