Learning to assemble objects with a robot swarm

Large populations of simple robots can solve complex tasks, but controlling them is still a challenging problem, due to limited communication and computation power. In order to assemble objects, have shown that a human controller can solve such a task. Instead, we investigate how to learn the assembly of multiple objects with a single central controller. We propose splitting the assembly process in two sub-tasks -- generating a top-level assembly policy and learning an object movement policy. The assembly policy plans the trajectories for each object and the object movement policy controls the trajectory execution.The resulting system is able to solve assembly tasks with varying object shapes being assembled as shown in multiple simulation scenarios

Impact of estrogen receptor alpha on the tamoxifen resistance in breast cancer patients

Genetic aberrations and changes in the activity of estrogen receptors alpha (ERa[lpha]) play an important role in the endocrine sensitivity. The aim of this study was to examine the relationship between the ESR1 expression level, its polymorphic variants, and the distribution pattern of ER[alpha] expression with the prognosis and efficacy of tamoxifen treatment in breast cancer patients. Our data suggest that the ESR1 expression level, SNPs in the ESR1 gene and the distribution pattern of ERα expression can be a potential molecular marker of tamoxifen resistance in breast cancer patients

DNA Barcoding for Community Ecology - How to Tackle a Hyperdiverse, Mostly Undescribed Melanesian Fauna

Trigonopterus weevils are widely distributed throughout Melanesia and hyperdiverse in New Guinea. They are a dominant feature in natural forests, with narrow altitudinal zonation. Their use in community ecology has been precluded by the "taxonomic impediment". We sampled >6,500 specimens from seven areas across New Guinea; 1,002 specimens assigned to 270 morphospecies were DNA sequenced. Objective clustering of a refined dataset (excluding nine cryptic species) at 3% threshold revealed 324 genetic clusters (DNA group count relative to number of morphospecies = 20.0% overestimation of species diversity, or 120.0% agreement) and 85.6% taxonomic accuracy (the proportion of DNA groups that "perfectly" agree with morphology-based species hypotheses). Agreement and accuracy were best at an 8% threshold. GMYC analysis revealed 328 entities (21.5% overestimation) with 227 perfect GMYC entities (84.1% taxonomic accuracy). Both methods outperform the parataxonomist (19% underestimation; 31.6% taxonomic accuracy). The number of species found in more than one sampling area was highest in the Eastern Highlands and Huon (Sørensen similarity index 0.07, 4 shared species); ⅓ of all areas had no species overlap. Success rates of DNA barcoding methods were lowest when species showed a pronounced geographical structure. In general, Trigonopterus show high α and β-diversity across New Guinea. DNA barcoding is an excellent tool for biodiversity surveys but success rates might drop when closer localities are included. Hyperdiverse Trigonopterus are a useful taxon for evaluating forest remnants in Melanesia, allowing finer-grained analyses than would be possible with vertebrate taxa commonly used to date. Our protocol should help establish other groups of hyperdiverse fauna as target taxa for community ecology. Sequencing delivers objective data on taxa of incredible diversity but mostly without a solid taxonomic foundation and should help pave the road for the eventual formal naming of new species

Identification of Potent Odorants in a Novel Nonalcoholic Beverage Produced by Fermentation of Wort with Shiitake (Lentinula edodes)

Novel refreshments with pleasant flavors were developed by fermentation of wort with basidiomycetes. Among 31 screened fungi, shiitake (Lentinula edodes) produced the most pleasant flavor. It was perceived as fruity, slightly sour, and plum-like. Flavor compounds were isolated by liquid–liquid extraction (LLE) and by headspace solid phase microextraction (HS-SPME). The key odor-active compounds were analyzed by a gas chromatography system equipped with a tandem mass spectrometry detector and an olfactory detection port (GC-MS/MS-O) and aroma extract dilution analysis (AEDA). For HS-SPME, a revised method of increasing the GC inlet split ratio was used. Most of the key odor-active compounds (e.g., 2-acetylpyrrole, β-damascenone, (<i>E</i>)-2-nonenal, and 2-phenylethanol) were detected with both extraction techniques. However, distinct differences between these two methods were observed

NaClO-Generated Iron(IV)oxo and Iron(V)oxo TAMLs in Pure Water

The unique properties of entirely aliphatic TAML activator [Fe^III{(Me₂C<i>N</i>COCMe₂<i>N</i>CO)₂CMe₂}­OH₂]⁻ (<b>3</b>), namely the increased steric bulk of the ligand and the unmatched resistance to the acid-induced demetalation, enables the generation of high-valent iron derivatives in pure water at any pH. An iron­(V)­oxo species is readily produced with NaClO at pH values from 2 to 10.6 without any observable intermediate. This is the first reported example of iron­(V)­oxo formed in pure water. At pH 13, iron­(V)­oxo is not formed and NaClO oxidizes <b>3</b> to an iron­(IV)­oxo derivative

A “Beheaded” TAML Activator: A Compromised Catalyst that Emphasizes the Linearity between Catalytic Activity and p<i>K</i>_a

Studies of the new tetra-amido macrocyclic ligand (TAML) activator [Fe^III{(Me₂C<i>N</i>COCMe₂<i>N</i>CO)₂CMe₂}­OH₂]⁻ (<b>4</b>) in water in the pH range of 2–13 suggest its pseudo-octahedral geometry with two nonequivalent axial H₂O ligands and revealed (i) the anticipated basic drift of the first p<i>K</i>_a of water to 11.38 due to four electron-donating methyl groups alongside (ii) its counterintuitive enhanced resistance to acid-induced iron­(III) ejection from the macrocycle. The catalytic activity of <b>4</b> in the oxidation of Orange II (S) by H₂O₂ in the pH range of 7–12 is significantly lower than that of previously reported TAML activators, though it follows the common rate law (<i>v</i>/[Fe^III] = <i>k</i>_I<i>k</i>_II[H₂O₂]­[S]/(<i>k</i>_I[H₂O₂] + <i>k</i>_II[S]) and typical pH profiles for <i>k</i>_I and <i>k</i>_II. At pH 7 and 25 °C the rate constants <i>k</i>_I and <i>k</i>_II equal 0.63 ± 0.02 and 1.19 ± 0.03 M^–1 s^–1, respectively. With these new values for p<i>K</i>_a, <i>k</i>_I and <i>k</i>_II establishing new high and low limits, respectively, the rate constants <i>k</i>_I and <i>k</i>_II were correlated with p<i>K</i>_a values of all TAML activators. The relations log <i>k</i> = log <i>k</i>⁰ + α × p<i>K</i>_a were established with log <i>k</i>⁰ = 13 ± 2 and 20 ± 4 and α = −1.1 ± 0.2 and −1.8 ± 0.4 for <i>k</i>_I and <i>k</i>_II, respectively. Thus, the reactivity of TAML activators across four generations of catalysts is predictable through their p<i>K</i>_a values

Activation of Dioxygen by a TAML Activator in Reverse Micelles: Characterization of an Fe^IIIFe^IV Dimer and Associated Catalytic Chemistry

Iron TAML activators of peroxides are functional catalase-peroxidase mimics. Switching from hydrogen peroxide (H₂O₂) to dioxygen (O₂) as the primary oxidant was achieved by using a system of reverse micelles of Aerosol OT (AOT) in <i>n</i>-octane. Hydrophilic TAML activators are localized in the aqueous microreactors of reverse micelles where water is present in much lower abundance than in bulk water. <i>n</i>-Octane serves as a proximate reservoir supplying O₂ to result in partial oxidation of Fe^III to Fe^IV-containing species, mostly the Fe^IIIFe^IV (major) and Fe^IVFe^IV (minor) dimers which coexist with the Fe^III TAML monomeric species. The speciation depends on the pH and the degree of hydration <i>w</i>₀, viz., the amount of water in the reverse micelles. The previously unknown Fe^IIIFe^IV dimer has been characterized by UV–vis, EPR, and Mössbauer spectroscopies. Reactive electron donors such as NADH, pinacyanol chloride, and hydroquinone undergo the TAML-catalyzed oxidation by O₂. The oxidation of NADH, studied in most detail, is much faster at the lowest degree of hydration <i>w</i>₀ (in “drier micelles”) and is accelerated by light through NADH photochemistry. Dyes that are more resistant to oxidation than pinacyanol chloride (Orange II, Safranine O) are not oxidized in the reverse micellar media. Despite the limitation of low reactivity, the new systems highlight an encouraging step in replacing TAML peroxidase-like chemistry with more attractive dioxygen-activation chemistry