cssi/SciSciGPT-SciSciNet huggingface dataset:
On the Anomalous Acceleration of 1I/2017 U1 'Oumuamua

We show that the P ~ 8 hr photometric period and the astrometrically measured A_(ng) ~ 2.5 × 10^(−4) cm s^(−2) non-gravitational acceleration (at r ~ 1.4 au) of the interstellar object 1I/2017 ('Oumuamua) can be explained by a nozzle-like venting of volatiles whose activity migrated to track the subsolar location on the object's surface. Adopting the assumption that 'Oumuamua was an elongated a × b × c ellipsoid, this model produces a pendulum-like rotation of the body and implies a long semi-axis a ∼ 5 A_(ng)P^2/4π^2 ∼ 260 m. This scale agrees with the independent estimates of 'Oumuamua's size that stem from its measured brightness, assuming an albedo of p ~ 0.1, which is appropriate for ices that have undergone long-duration exposure to the interstellar cosmic-ray flux. Using ray tracing, we generate light curves for ellipsoidal bodies that are subject to both physically consistent subsolar torques and to the time-varying geometry of the Sun–Earth–'Oumuamua configuration. Our synthetic light curves display variations from chaotic tumbling and changing cross-sectional illumination that are consistent with the observations, while avoiding significant secular changes in the photometric periodicity. If our model is correct, 'Oumuamua experienced mass loss that wasted ~10% of its total mass during the ~100 days span of its encounter with the inner solar system and had an icy composition with a very low [C/O] ≲ 0.003. Our interpretation of 'Oumuamua's behavior is consistent with the hypothesis that it was ejected from either the outer regions of a planetesimal disk after an encounter with an embedded M_p ~ M_(Nep) planet, or from an exo-Oort cloud.
DART: Diversity-Enhanced Autonomy in Robot Teams

This paper defines the research area of Diversity-enhanced Autonomy in Robot Teams (DART), a novel paradigm for the creation and design of policies for multi-robot coordination. Although current ap...
Dietary fiber intake and glycemic control: coronary artery calcification in type 1 diabetes (CACTI) study

Dietary fiber has been recommended for glucose control, and typically low intakes are observed in the general population. The role of fiber in glycemic control in reported literature is inconsistent and few reports are available in populations with type 1 diabetes (T1D). Using data from the Coronary Artery Calcification in Type 1 Diabetes (CACTI) study [n = 1257; T1D: n = 568; non-diabetic controls: n = 689] collected between March 2000 and April 2002, we examined cross-sectional (baseline) and longitudinal (six-year follow-up in 2006–2008) associations of dietary fiber and HbA1c. Participants completed a validated food frequency questionnaire, and a physical examination and fasting biochemical analyses (12 h fast) at baseline visit and at the year 6 visit. We used a linear regression model stratified by diabetes status, and adjusted for age, sex and total calories, and diabetes duration in the T1D group. We also examined correlations of dietary fiber with HbA1c. Baseline dietary fiber intake and serum HbA1c in the T1D group were 16 g [median (IQ): 11–22 g) and 7.9 ± 1.3% mean (SD), respectively, and in the non-diabetic controls were 15 g [median (IQ): 11–21 g) and 5.4 ± 0.4%, respectively. Pearson partial correlation coefficients revealed a significant but weak inverse association of total dietary fiber with HbA1c when adjusted for age, sex, diabetes status and total calories (r = − 0.07, p = 0.01). In the adjusted linear regression model at baseline, total dietary fiber revealed a significant inverse association with HbA1c in the T1D group [β ± SE = − 0.32 ± 0.15, p = 0.034], as well as in the non-diabetic controls [− 0.10 ± 0.04, p = 0.009]. However, these results were attenuated after adjustment for dietary carbohydrates, fats and proteins, or for cholesterol and triglycerides. No such significance was observed at the year 6 follow-up, and with the HbA1c changes over 6 years. Thus, at observed levels of intake, total dietary fiber reveals modest inverse associations with poor glycemic control. Future studies must further investigate the role of overall dietary quality adjusting for fiber-rich foods in T1D management.
Structure and mechanism of a Hypr GGDEF enzyme that activates cGAMP signaling to control extracellular metal respiration.

A newfound signaling pathway employs a GGDEF enzyme with unique activity compared to the majority of homologs associated with bacterial cyclic di-GMP signaling. This system provides a rare opportunity to study how signaling proteins natively gain distinct function. Using genetic knockouts, riboswitch reporters, and RNA-Seq, we show that GacA, the Hypr GGDEF in Geobacter sulfurreducens, specifically regulates cyclic GMP-AMP (3',3'-cGAMP) levels in vivo to stimulate gene expression associated with metal reduction separate from electricity production. To reconcile these in vivo findings with prior in vitro results that showed GacA was promiscuous, we developed a full kinetic model combining experimental data and mathematical modeling to reveal mechanisms that contribute to in vivo specificity. A 1.4 A-resolution crystal structure of the Geobacter Hypr GGDEF domain was determined to understand the molecular basis for those mechanisms, including key cross-dimer interactions. Together these results demonstrate that specific signaling can result from a promiscuous enzyme.
Preclinical insights into cholangiopathies: disease modeling and emerging therapeutic targets.

Introduction: The common predominant clinical features of cholangiopathies such as primary sclerosing cholangitis (PSC), primary biliary cholangitis (PBC), and biliary atresia (BA) are biliary dama...
Dual TGFβ/BMP Pathway Inhibition Enables Expansion and Characterization of Multiple Epithelial Cell Types of the Normal and Cancerous Breast

Functional modeling of normal breast epithelial hierarchy and stromal-epithelial cell interactions have been difficult due to inability to obtain sufficient stem-progenitor-mature epithelial and stromal cells. Recently reported epithelial reprogramming assay has partially overcome this limitation, but cross-contamination of cells from the feeder layer is a concern. The purpose of this study was to develop a feeder-layer-independent and inexpensive method to propagate multiple cell types from limited tissue resources. Cells obtained after enzymatic digestion of tissues collected at surgery or by core-needle biopsies were plated on tissue culture dishes precoated with laminin-5-rich-conditioned media from the rat bladder tumor cell line 804G and a defined growth media with inhibitors of ROCK, TGFβ, and BMP signaling. Cells were characterized by flow cytometry, mammosphere assay, 3D cultures, and xenograft studies. Cells from the healthy breasts included CD10+/EpCAM- basal/myoepithelial, CD49f+/EpCAM+ luminal progenitor, CD49f-/EpCAM+ mature luminal, CD73+/EpCAM+/CD90- rare endogenous pluripotent somatic stem, CD73+/CD90+/EpCAM-, estrogen receptor alpha-expressing ALCAM (CD166)+/EpCAM+, and ALDFLUOR+ stem/luminal progenitor subpopulations. Epithelial cells were luminal (KRT19+), basal (KRT14+), or dual-positive luminal/basal hybrid cells. While breast cells derived from BRCA1, BRCA2, and PALB2 mutation carriers did not display unique characteristics, cells from women with breast cancer-protective alleles showed enhanced differentiation. Cells could also be propagated from primary tumors and metastasis of breast, ovarian, and pancreatic cancer-neuroendocrine subtype. Xenograft studies confirmed tumorigenic properties of tumor-derived cells. IMPLICATIONS: Our method expands the scope of individualized studies of patient-derived cells and provides resources to model epithelial-stromal interactions under normal and pathologic conditions.
Community Engagement Professionals as Inquiring Practitioners for Organizational Learning.

This essay examines the inquiry activities that community engagement professionals (CEPs) can utilize to support organizational learning. We advocate for an inquiry approach that focuses on improvement and informing community-engaged practices and organizational change. By unpacking why inquiry is imperative for CEPs and outlining the tensions that may arise, we introduce three concepts: inquiry consists of different yet connected activities including, but not limited to, assessing student learning; CEPs are key knowledge workers in higher education; and, finally, CEPs can and should leverage inquiry to inform institutional planning and systematically align policies, processes, and procedures to demonstrate our public missions for society and other key stakeholders.
Excimer Laser Technology

Scaling presently available excimer laser systems to lasers designed to operate at high average power and high pulse repetition rates for long periods of time requires advances in many areas of engineering technology. For economical application to industrial processes, the efficiency must be increased. This leads to more stringent requirements on preionization techniques, energy delivery systems, and system chemistry. Long life operation (>109 to 1010 pulses) requires development of new pulse power components, optical ele-ments, and flow system components. A broad-based program underway at the Los Alamos National Laboratory is addressing these key technology issues, with the help of advanced component and systems development programs in industry. A prototype XeCI laser meeting all requirements for efficiency, system performance, and life is scheduled for completion in 1985.
Something's Brewing! Early Prediction of Controversy-causing Posts from Discussion Features.

Controversial posts are those that split the preferences of a community, receiving both significant positive and significant negative feedback. Our inclusion of the word “community” here is deliberate: what is controversial to some audiences may not be so to others. Using data from several different communities on reddit.com, we predict the ultimate controversiality of posts, leveraging features drawn from both the textual content and the tree structure of the early comments that initiate the discussion. We find that even when only a handful of comments are available, e.g., the first 5 comments made within 15 minutes of the original post, discussion features often add predictive capacity to strong content-and- rate only baselines. Additional experiments on domain transfer suggest that conversation- structure features often generalize to other communities better than conversation-content features do.
Carboxylic sulfonic mixed anhydrides: General utility and application to the synthesis of ceftazidime

Abstract A high-yielding acylation process which utilizes a mixed anhydride of the type RCO2SO2CH3 for the synthesis of the cephalosporin ceftazidime is detailed. The mixed anhydride is conveniently prepared by addition of methanesulfonyl chloride to the triethylammonium salt of the acid 2a. Although known for some time, these anhydrides have not been used often in acylations. This lack of general utility is explained by side reactions, especially formation of the carboxylic symmetric anhydride in sterically unhindered systems.
Instabilities in the Linear Sb Atom Chain of the New Binary Antimonide Ti11-xSb8-y

The new binary antimonide Ti11-xSb8-y was prepared from directly reacting the elements in stoichiometric ratios, either by melting the reaction mixture in an arc furnace or by annealing it in a resistance furnace above 1000 °C. Ti11-xSb8-y is a nonstoichiometric compound with a small phase range that cannot be prepared with the idealized Ti:Sb ratio of 11:8. Ti10.84(3)Sb7.74(1) crystallizes in the Cr11Ge8 type, isostructural with (Zr,V)11Sb8: space group Pnma, lattice dimensions a = 1462.28(9) pm, b = 559.72(4) pm, c = 1764.4(1) pm, V = 1.4441(2) nm3 (Z = 4). One can describe this type as an intergrowth of distorted fragments of the NiAs and W5Si3 types. In addition to the dominating heteronuclear Ti−Sb bonds, the structure of Ti11-xSb8-y comprises several homonuclear Ti−Ti and Sb−Sb bonding interactions. Short bonds of alternating 276 and 284 pm occur in a linear nonclassical chain of mainly Sb atoms (i.e., 87% Sb and 13% Ti). According to our experiments, the incorporation of Ti atoms into this chain, ...
The lifetimes of spiral patterns in disc galaxies

The rate of internally driven evolution of galaxy discs is strongly affected by the lifetimes of the spiral patterns they support. Evolution is much faster if the spiral patterns are recurrent short-lived transients rather than long-lived, quasi-steady features. As rival theories are still advocated based on these two distinct hypotheses, I review the evidence that bears on the question of the lifetimes of spiral patterns in galaxies. Observational evidence from external galaxies is frustratingly inconclusive, but the velocity distribution in the solar neighbourhood is more consistent with the transient picture. I present simulations of galaxy models that have been proposed to support quasi-steady, two-arm spiral modes that in fact evolve quickly due to multi-arm instabilities. I also show that all simulations to date manifest short-lived patterns, despite claims to the contrary. Thus the transient hypothesis is favoured by both numerical results and the velocity distribution in the solar neighbourhood.
Preparation of N-alkyl pyrrolidinones via photocyclization of γ-keto-α,β-unsaturated amides

Abstract Photolysis of γ-keto-α,β-unsaturated amides provides N-alkyl pyrrolidinones in high yield (77–;100%). The procedure is applicable to a variety of amides derived from the corresponding γ-keto acid.
The Darzens condensation of α,β-unsaturated aldehydes and ketones

The one-pot Darzens condensation of α,β-unsaturated aldehydes and ketones with enolates of an α-bromo ester or ketone is described.
Palladium-catalyzed cross-coupling of aryl chlorides with alkenylboronic acids with low E/Z isomerization

Using a bulky electron-rich monodentate benzoferrocenyl phosphine as supporting ligand, an efficient protocol for stereoselective palladium-catalyzed Suzuki–Miyaura cross-coupling of aryl chlorides with alkenylboronic acids was uncovered. Using this protocol, both trans- and cis-alkenylboronic acids can be coupled with high stereoselectivity giving the corresponding vinylarenes in good to quantitative yields. Electron-poor and -rich aryl chlorides including highly hindered ones are all suitable substrates for the reaction.
Reciprocal control of motility and biofilm formation by the PdhS2 two-component sensor kinase of Agrobacterium tumefaciens

A core regulatory pathway that directs developmental transitions and cellular asymmetries in Agrobacterium tumefaciens involves two overlapping, integrated phosphorelays. One of these phosphorelays putatively includes four histidine sensor kinase homologues, DivJ, PleC, PdhS1 and PdhS2, and two response regulators, DivK and PleD. In several different alphaproteobacteria, this pathway influences a conserved downstream phosphorelay that ultimately controls the phosphorylation state of the CtrA master response regulator. The PdhS2 sensor kinase reciprocally regulates biofilm formation and swimming motility. In the current study, the mechanisms by which the A. tumefaciens sensor kinase PdhS2 directs this regulation are delineated. PdhS2 lacking a key residue implicated in phosphatase activity is markedly deficient in proper control of attachment and motility phenotypes, whereas a kinase-deficient PdhS2 mutant is only modestly affected. A genetic interaction between DivK and PdhS2 is revealed, unmasking one of several connections between PdhS2-dependent phenotypes and transcriptional control by CtrA. Epistasis experiments suggest that PdhS2 may function independently of the CckA sensor kinase, the cognate sensor kinase for CtrA, which is inhibited by DivK. Global expression analysis of the pdhS2 mutant reveals a restricted regulon, most likely functioning through CtrA to separately control motility and regulate the levels of the intracellular signal cyclic diguanylate monophosphate (cdGMP), thereby affecting the production of adhesive polysaccharides and attachment. We hypothesize that in A. tumefaciens the CtrA regulatory circuit has expanded to include additional inputs through the addition of PdhS-type sensor kinases, likely fine-tuning the response of this organism to the soil microenvironment.
Water transmission potential of Angiostrongylus cantonensis: Larval viability and effectiveness of rainwater catchment sediment filters.

Neuroangiostrongyliasis, caused by Angiostrongylus cantonensis, has been reported in Hawaiʻi since the 1950's. An increase in cases is being reported primarily from East Hawaiʻi Island, correlated with the introduction of the semi-slug Parmarion martensi. Households in areas lacking infrastructure for water must use rainwater catchment as their primary domestic water supply, for which there is no federal, state, or county regulation. Despite evidence that slugs and snails can contaminate water and cause infection, regulatory bodies have not addressed this potential transmission route. This study evaluates: 1) the emergence of live, infective-stage A. cantonensis larvae from drowned, non-native, pestiforous gastropods; 2) larvae location in an undisturbed water column; 3) longevity of free-living larvae in water; and 4) effectiveness of rainwater catchment filters in blocking infective-stage larvae. Larvae were shed from minced and whole gastropods drowned in either municipal water or rainwater with ~94% of larvae recovered from the bottom of the water column 72–96 hours post drowning. Infective-stage larvae were active for 21 days in municipal water. Histological sectioning of P. martensi showed proximity of nematode larvae to the body wall of the gastropod, consistent with the potential for shedding of larvae in slime. Gastropod tissue squashes showed effectivity as a quick screening method. Live, infective-stage larvae were able to traverse rainwater catchment polypropylene sediment filters of 20 μm, 10 μm, 5 μm, and 1 μm filtration ratings, but not a 5 μm carbon block filter. These results demonstrate that live, infective-stage A. cantonensis larvae emerge from drowned snails and slugs, survive for extended periods of time in water, and may be able to enter a catchment user's household water supply. This study illustrates the need to better investigate and understand the potential role of contaminated water as a transmission route for neuroangiostrongyliasis.
Stereoselective trans- and cis-Dihydroxylations of 2H-Pyranyl and Dihydropyridinyl Heterocycles Synthesized from Formal [3 + 3]-Cycloaddition Reactions of α,β-Unsaturated Iminium Ions with 1,3-Dicarbonyl Equivalents†

We describe here an inherent problem in direct epoxidation of the endocyclic olefin in 2H-pyrans fused to 2-pyrones. Such difficulties led to the development of highly stereoselective trans- and cis-dihydroxylations of these olefinic systems in both 2H-pyrans and dihydropyridines fused to a 2-pyrones or a 2-cyclohexenone. Protocols for the removal of the activated allylic hydroxyl group are also reported.
Multidrug resistance of cancer cells

Publisher Summary This chapter focuses primarily on recent reports relating to issues that remain unresolved in the field of multidrug-resistance and on developments that have come to the forefront in the past few years. After a brief overview of mdr genes and P-glycoprotein, (Pgp) activity, it discusses the clinical relevance of the human MDR1 gene and Pgp, the mechanism by which Pgp confers drug-resistance and the regulation of MDR1 gene activity in normal and cancer cells. The chapter briefly reviews what is known about other cellular mechanisms for conferring resistance to mdr-related drugs and the clinical aspect of mdr by discussing prospects for overcoming multidrug-resistance in light of what is now known about its mechanisms of action. MDR1 or mdr has been used generically to refer to mammalian genes functional in conferring multidrug-resistance.
IMPROVED PROCEDURE FOR THE LARGE SCALE SYNTHESIS OF 1,2,3,4,4a,9b-HEXAHYDRODIBENZOTHIOPHENE

(2000). IMPROVED PROCEDURE FOR THE LARGE SCALE SYNTHESIS OF 1,2,3,4,4a,9b-HEXAHYDRODIBENZOTHIOPHENE. Organic Preparations and Procedures International: Vol. 32, No. 2, pp. 169-173.
Studies on the total synthesis of paraherquamide A. Stereocontrolled, asymmetric synthesis of α-alkyl-β-hydroxyproline derivatives

Abstract The dianion formed from 3(S),2(R)-3-hydroxyproline ethyl ester (5) with LDA, can be alkylated with a variety of alkyl halides with net retention of configuration to give the corresponding α-alkylated-β-hydroxyproline esters (6) in good yield.
Convenient one-pot synthesis of 5-(substituted amino)-1,2,3,4-thiatriazoles

5-(Substituted amino)-1,2,3,4-thiatriazoles 15a – 15i were conveniently synthesized in 73–97% yields in a one-pot procedure from bis(1 H -benzotriazol-1-yl)methanethione and amines.
Single crystal growth and characterization of the reduced barium sodium siliconiobate, Ba3Na0.32Nb6O12(Si2O7)2

Abstract Single crystals of Ba3Na0.32Nb6O12(Si2O7)2 were grown for the first time. The use of an alkali/alkaline earth eutectic flux facilitated the crystal growth. Ba3Na0.32Nb6O12(Si2O7)2, a mixed valent Nb(V)/Nb(IV) compound, crystallizes in the noncentrosymmetric hexagonal space group P-62m with a = 8.9998(10) A and c = 7.8119(17) A. The temperature dependence of the magnetic susceptibility was measured and found to be paramagnetic across the entire 2–300 K temperature range measured. Although noncentrosymmetric, Ba3Na0.32Nb6O12(Si2O7)2 was not found to be second harmonic generation active. Ba3Na0.32Nb6O12(Si2O7)2 was further characterized by IR and UV/Vis spectroscopies.
Synthesis and Evaluation of Duocarmycin and CC-1065 Analogues Containing Modifications in the Subunit Linking Amide

The preparation and evaluation of 6 and 7, analogues of the duocarmycins and CC-1065 in which the subunit linking amide has been replaced with an amidine and thioamide, are described. Consistent with the increased electron-withdrawing properties and conjugation of thioamides relative to amides, 7 showed increased solvolysis reactivity (t1/2, 160 h versus 230 h) at pH 3, attributable to a diminished vinylogous amide stabilization of the reacting alkylation subunit. Amidine 6 proved to be even more unstable (t1/2, 12 h) despite the diminished electron-withdrawing properties, but underwent preferential N2 amidine linkage hydrolysis rather than solvolysis of the alkylation subunit, attributable to preferential N2 vinylogous amide versus amidine conjugation. The natural isomers (+)-6 and (+)-7 exhibited an identical DNA alkylation selectivity as (+)-CBI-TMI and (+)-duocarmycin SA but were less efficient (10-100×). Biological studies of (+)-6 and (+)-7 (0.75 and 1.1 nM, respectively) indicated the analogues retained good cytotoxic activities (L1210), but were less potent than (+)-duocarmycin SA (0.01 nM, 100×) and (+)-CBI-TMI (0.02 nM, 50×). The enhanced properties of the linking amide versus amidine or thioamide established the N2 amide as the optimal linking unit examined to date and revealed that it provides a beautiful balance between competing amide (reactivity) and vinylogous amide (stability) conjugation.
Mn(III)-based oxidative free-radical cyclizations of alkenyl Meldrum's acids

Abstract Oxidative cyclization of unsaturated Meldrum's acids can be carried out at temperatures as low as −30°C. The rate-determining step is cyclization of the enolate to the alkene ( 11 to 14 and 15 ) rather than enolization, which is the rate-determining step with dimethyl 4-pentenylmalonate ( 1 ). While cyclization of 1 gives mainly cyclopentanes, cyclization of Meldrum's acids provides a versatile route to cyclohexenes.
Synthesis and characterization of quinone-substituted octaalkyl porphyrin monomers and dimers

The synthesis and characterization of a variety of selectively metalated quinone-substituted zinc-containing octaalkyl porphyrin dimers, designed to mimic certain key electronic and structural aspects of the photosynthetic reaction centers of Rhodopseudomonas viridis and Rhodobacter sphaeroides, and appropriate control monomers and dimers are described. These new compounds have been characterized by {sup 1}H NMR, {sup 13}C NMR, UV-visible spectroscopy, mass spectrometry, and microanalysis. Electrochemical data are also given for representative dimers and monomers and X-ray structural information is provided for a 1,3-phenyl-linked and a 1,4-phenyl-linked functionalized copper-containing dimer and for a quinone-substituted metal-free monomer.
Non-neutral evolution of H3.3-encoding genes occurs without alterations in protein sequence

Histone H3.3 is a developmentally essential variant encoded by two independent genes in human (H3F3A and H3F3B). While this two-gene arrangement is evolutionarily conserved, its origins and function remain unknown. Phylogenetics, synteny and gene structure analyses of H3.3 genes from 32 metazoan genomes indicate independent evolutionary paths for H3F3A and H3F3B. While H3F3B bears similarities with H3.3 genes in distant organisms and with canonical H3 genes, H3F3A is sarcopterygian-specific and evolves under strong purifying selection. Additionally, H3F3B codon-usage preferences resemble those of broadly expressed genes and 'cell differentiation-induced' genes, while codon-usage of H3F3A resembles that of 'cell proliferation-induced' genes. We infer that H3F3B is more similar to the ancestral H3.3 gene and likely evolutionarily adapted for a broad expression pattern in diverse cellular programs, while H3F3A adapted for a subset of gene expression programs. Thus, the arrangement of two independent H3.3 genes facilitates fine-tuning of H3.3 expression across cellular programs.
High temperature synthesis of two open-framework uranyl silicates with ten-ring channels: Cs2(UO2)2Si8O19 and Rb2(UO2)2Si5O13

Abstract The uranyl silicates Cs 2 (UO 2 ) 2 Si 8 O 19 and Rb 2 (UO 2 ) 2 Si 5 O 13 were obtained by mixing stoichiometric amounts of uranium metal, tellurium dioxide, silicon dioxide, and an excess of correspondent alkali metal halide flux. These compounds crystallize in the orthorhombic space groups Pnma and C 222 with eight and two units per unit cell, respectively. Their crystal structures are dominated by zippered pentagonal bipyramidal chains of UO 7 and silicates layer that are further connected into 3D frameworks. The cesium compound has silicate double layers while rubidium has a single layer. Six-ring voids and ten-ring channels are found in both compounds.
Synthesis and properties of thiolactam analogs of pyrromethenones

Thiolactam analogs of kryptopyrromethenone and xanthobilirubic acid methyl ester were prepared from the parent pyrromethenone using Lawesson's reagent and are shown to form dimeric association complexes through intermolecular hydrogen bonding.
Synthesis and biological evaluation of deoxypreussomerin A and palmarumycin CP1 and related naphthoquinone spiroketals

Abstract Oxidative cyclization of bis-hydroxynaphthyl ethers allows concise total syntheses of palmarumycin CP 1 and deoxypreussomerin A in 8-9 steps and 15–35% overall yield from 5-hydroxy-8-methoxy-1-tetralone ( 8 ). Polymer-bound triphenyl phosphine was found to be a superior reagent for the rapid preparation of a small library of palmarumycin analogs. Preliminary biological evaluation of naphthoquinone spiroketals against MCF-7 and MDA-MB-231 human breast cancer cells revealed several low-micromolar growth inhibitors.
A universal allyl linker for solid-phase synthesis

Abstract We report synthesis of a universal allyl linker for solid-phase synthesis, 9-O-(4,4′-Dimethoxytrityl)-10-undecenoic (3), that has a reactive terminal double bond. Since allyl cleavage occurs under conditions orthogonal to those used during the solid-phase synthesis and deprotection of DNA or RNA fragments, this linker extends the range of post-synthetic manipulations that can be carried out without cleavage from the support, and means that this linkage could be used to construct affinity columns. Alternatively, it should be possible also to cleave fully protected molecules from the support if so desired.
Catalytic asymmetric hydrogenation of aromatic ketones in room temperature ionic liquids

Abstract Polar bisphosphonic acid-derived Ru(BINAP)(DPEN)Cl 2 precatalysts were synthesized and immobilized in room temperature ionic liquids (RTILs) for asymmetric hydrogenation of aromatic ketones with ee values of up to 98.7%. The performance of the Ru catalysts is highly dependent on the nature of imidazolium ILs. For the imidazolium ILs without acidic protons, both ILs and Ru catalysts were recycled by simple extraction and reused. Such a simple immobilization approach also prevented the leaching of Ru (and Ru catalysts) into the chiral secondary alcohol products, and should prove desirable for the production of pharmaceutical intermediates that are free from metal contaminants.
An efficient method for the synthesis of aromatic C-nucleosides

Abstract Reaction of diarylcadmium or diarylzinc reagents with 1,2-dideoxy-3,5-di-O-p-toluoyl-1-chloro-α-D-ribofuranose affords 3,5-di-O-protected aromatic C-nucleosides in good yields.
Intramolecular C−H Insertion Reactions of (η5-Cyclopentadienyl)dicarbonyliron Carbene Complexes: Scope of the Reactions and Application to the Synthesis of (±)-Sterpurene and (±)-Pentalenene

(η5-Cyclopentadienyl)dicarbonyliron carbene complexes, [(η5-C5H5)(CO)2FeCHR]+BF4-, are generated as reactive intermediates from thioether derivatives, (η5-C5H5)(CO)2FeCH(R)SPh, by S-alkylation with...
Multilayer View of Pathogenic SNVs in Human Interactome through In Silico Edgetic Profiling

Non-synonymous mutations linked to the complex diseases often have a global impact on a biological system, affecting large biomolecular networks and pathways. However, the magnitude of the mutation-driven effects on the macromolecular network is yet to be fully explored. In this work, we present a systematic multi-level characterization of human mutations associated with genetic disorders by determining their individual and combined interaction-rewiring, "edgetic," effects on the human interactome. Our in silico analysis highlights the intrinsic differences and important similarities between the pathogenic single-nucleotide variants (SNVs) and frameshift mutations. We show that pathogenic SNVs are more likely to cause gene pleiotropy than pathogenic frameshift mutations and are enriched on the protein interaction interfaces. Functional profiling of SNVs indicates widespread disruption of the protein-protein interactions and synergistic effects of SNVs. The coverage of our approach is several times greater than the recently published experimental study and has the minimal overlap with it, while the distributions of determined edgotypes between the two sets of profiled mutations are remarkably similar. Case studies reveal the central role of interaction-disrupting mutations in type 2 diabetes mellitus and suggest the importance of studying mutations that abnormally strengthen the protein interactions in cancer. With the advancement of next-generation sequencing technology that drives precision medicine, there is an increasing demand in understanding the changes in molecular mechanisms caused by the patient-specific genetic variation. The current and future in silico edgotyping tools present a cheap and fast solution to deal with the rapidly growing data sets of discovered mutations.
MIN1PIPE: A Miniscope 1-photon-based Calcium Imaging Signal Extraction Pipeline

In vivo calcium imaging using a 1-photon-based miniscope and a microendoscopic lens enables studies of neural activities in freely behaving animals. However, the high and fluctuating background, the inevitable movements and distortions of imaging field, and the extensive spatial overlaps of fluorescent signals emitted from imaged neurons inherent in this 1-photon imaging method present major challenges for extracting neuronal signals reliably and automatically from the raw imaging data. Here, we develop a unifying algorithm called the miniscope 1-photon imaging pipeline (MIN1PIPE), which contains several stand-alone modules and can handle a wide range of imaging conditions and qualities with minimal parameter tuning and automatically and accurately isolate spatially localized neural signals. We have quantitatively compared MIN1PIPE with other existing partial methods using both synthetic and real datasets obtained from different animal models and show that MIN1PIPE has superior efficiency and precision in analyzing noisy miniscope calcium imaging data.
The catalytic nanodiode. Its role in catalytic reaction mechanisms in a historical perspective

Catalytic nanodiodes, Pt/TiO2 or Pt/GaN produce continuous flow of hot electron current during carbon monoxide oxidation for hours in the 80–150 °C temperature range at pressures of 100 Torr of O2 and 40 Torr of CO. These observations provide proof of the Schottky diode model of oxide supported metal catalysis of many reactions that have been proposed by Schwab, Solymosi and others since the 1960s. The flow of hot electrons should influence chemistry at oxide–metal interfaces and the metal particle size dependence of catalytic activity and selectivity.
Female vocalizations predict reproductive output in brown-headed cowbirds (Molothrus ater).

Pair bonds are often maintained through the reciprocal and coordinated exchange of communicative signals. The ability to recognize and appropriately respond to a partner’s signals will define a pair’s ability to reproduce. Individual variation in responsiveness, by shaping the formation and maintenance of strong pair bonds, will ultimately influence an individual’s reproductive output. Throughout the breeding period, female cowbirds (Molothrus ater) respond to male song displays using a vocalization known as the chatter. In this study, we investigated whether variation in chatters remained repeatable across years and predicted reproductive performance. A flock of cowbirds housed in a large aviary complex was observed during the spring of 2011 to 2012. We recorded courtship interactions, including singing behavior for males, and chatters and eggs laid by females. The rate with which females responded to song using chatters remained consistent across years, with some females predictably responding to more songs using chatters than others. During 2012, chattering predicted the number of eggs females laid and her paired status. Paired females were more likely to respond to songs with chatters, and there was a strong positive relationship between the number of eggs laid and the proportion of songs she responded to using chatters. Overall, these findings suggest that variation in female vocal behavior is associated with their reproductive success.
Greener organic syntheses under non-traditional conditions

A solvent-free approach that involves microwave (MW) exposure of neat reactants (undiluted) catalyzed by the surfaces of less-expensive and recyclable mineral supports such as alumina, silica, clay, or ‘doped’ surfaces is presented which is applicable to a wide range of cleavage, condensation, cyclization, rearrangement, oxidation and reduction reactions including rapid one-pot assembly of heterocyclic compounds from in situ generated reactive intermediates. The strategy is adaptable to multi-component reactions e.g. Ugi and Biginelli reactions for rapid assembly of a library of compounds. Synthesis of a wide variety of significant precursors and intermediates namely, enones, imines, enamines, nitroalkenes, and oxidized sulfur species is possible and their value in concise MW synthesis of 2-aroylbenzofurans, and thiazole derivatives is illustrated. Ultrasound- and MW-assisted solventless preparation of ionic liquids and their application in alkylation and metal-catalyzed multi-component reactions is described. Efficient reaction of epoxides with carbon dioxide provides ready access to cyclic carbonates using only a catalytic amount of recyclable indium-based ionic liquid. MW heating in aqueous reaction media enables expeditious N-alkylation reactions of amines and hydrazines to afford a series of heterocyclic ring systems such as N-azacycloalkanes, 4,5-dihydropyrazoles, pyrazolidines etc.
Catalytic Approaches to the Synthesis of β-Lactamase Inhibitors

Abstract Catalytic couplings were utilized to stereospecifically synthesize several 7 E - and 7 Z -alkylidenecephalosporins. Members of this class are known inhibitors of β-lactamase. Zinc/NH 4 Cl reduction of dibromide 14 stereospecifically produced E -monobromide, 15 . In contrast, treatment of 14 with isopropylmagnesium bromide, followed by mild acid, stereospecifically produced Z -monobromide 27 . These reactions involve stable, intermediate α-(metalloalkylidene)-β-lactams. Monobromides 15 and 27 were stereospecifically coupled to organostannanes, or were converted to the corresponding organostannanes, 22 and 32 , which coupled with organohalides.
How sample heterogeneity can obscure the signal of microbial interactions

Microbial community data are commonly subjected to computational tools such as correlation networks, null models, and dynamic models, with the goal of identifying the ecological processes structuring microbial communities. A major assumption of these methods is that the signs and magnitudes of species interactions and vital rates can be reliably parsed from observational data on species’ (relative) abundances. However, we contend that this assumption is violated when sample units contain any underlying spatial structure. Here, we show how three phenomena—Simpson’s paradox, context-dependence, and nonlinear averaging—can lead to erroneous conclusions about population parameters and species interactions when samples contain heterogeneous mixtures of populations or communities. At the root of this issue is the fundamental mismatch between the spatial scales of species interactions (micrometers) and those of typical microbial community samples (millimeters to centimetres). These issues can be overcome by measuring and accounting for spatial heterogeneity at very small scales, which will lead to more reliable inference of the ecological mechanisms structuring natural microbial communities.
Efficient Online Multi-Person 2D Pose Tracking With Recurrent Spatio-Temporal Affinity Fields

We present an online approach to efficiently and simultaneously detect and track 2D poses of multiple people in a video sequence. We build upon Part Affinity Field (PAF) representation designed for static images, and propose an architecture that can encode and predict Spatio-Temporal Affinity Fields (STAF) across a video sequence. In particular, we propose a novel temporal topology cross-linked across limbs which can consistently handle body motions of a wide range of magnitudes. Additionally, we make the overall approach recurrent in nature, where the network ingests STAF heatmaps from previous frames and estimates those for the current frame. Our approach uses only online inference and tracking, and is currently the fastest and the most accurate bottom-up approach that is runtime-invariant to the number of people in the scene and accuracy-invariant to input frame rate of camera. Running at $\sim$30 fps on a single GPU at single scale, it achieves highly competitive results on the PoseTrack benchmarks.
Soft covering with high probability

Wyner's soft-covering lemma is the central analysis step for achievability proofs of information theoretic security, resolvability, and channel synthesis. It can also be used for simple achievability proofs in lossy source coding. This work sharpens the claim of soft-covering by moving away from an expected value analysis. Instead, a random codebook is shown to achieve the soft-covering phenomenon with high probability. The probability of failure is super-exponentially small in the block-length, enabling many applications through the union bound. This work gives bounds for both the exponential decay rate of total variation and the second-order codebook rate for soft covering.
Fast and Sample Near-Optimal Algorithms for Learning Multidimensional Histograms

We study the problem of robustly learning multi-dimensional histograms. A $d$-dimensional function $h: D \rightarrow \mathbb{R}$ is called a $k$-histogram if there exists a partition of the domain $D \subseteq \mathbb{R}^d$ into $k$ axis-aligned rectangles such that $h$ is constant within each such rectangle. Let $f: D \rightarrow \mathbb{R}$ be a $d$-dimensional probability density function and suppose that $f$ is $\mathrm{OPT}$-close, in $L_1$-distance, to an unknown $k$-histogram (with unknown partition). Our goal is to output a hypothesis that is $O(\mathrm{OPT}) + \epsilon$ close to $f$, in $L_1$-distance. We give an algorithm for this learning problem that uses $n = \tilde{O}_d(k/\epsilon^2)$ samples and runs in time $\tilde{O}_d(n)$. For any fixed dimension, our algorithm has optimal sample complexity, up to logarithmic factors, and runs in near-linear time. Prior to our work, the time complexity of the $d=1$ case was well-understood, but significant gaps in our understanding remained even for $d=2$.
Coalescent Histories for Lodgepole Species Trees

Abstract Coalescent histories are combinatorial structures that describe for a given gene tree and species tree the possible lists of branches of the species tree on which the gene tree coalescences take place. Properties of the number of coalescent histories for gene trees and species trees affect a variety of probabilistic calculations in mathematical phylogenetics. Exact and asymptotic evaluations of the number of coalescent histories, however, are known only in a limited number of cases. Here we introduce a particular family of species trees, the lodgepole species trees (λn)n≥0, in which tree λn has m=2n+1 taxa. We determine the number of coalescent histories for the lodgepole species trees, in the case that the gene tree matches the species tree, showing that this number grows with m!! in the number of taxa m. This computation demonstrates the existence of tree families in which the growth in the number of coalescent histories is faster than exponential. Further, it provides a substantial improvement...
Predictability of Popularity: Gaps between Prediction and Understanding

Can we predict the future popularity of a song, movie or tweet? Recent work suggests that although it may be hard to predict an item's popularity when it is first introduced, peeking into its early adopters and properties of their social network makes the problem easier. We test the robustness of such claims by using data from social networks spanning music, books, photos, and URLs. We find a stronger result: not only do predictive models with peeking achieve high accuracy on all datasets, they also generalize well, so much so that models trained on any one dataset perform with comparable accuracy on items from other datasets. Though practically useful, our models (and those in other work) are intellectually unsatisfying because common formulations of the problem, which involve peeking at the first small-k adopters and predicting whether items end up in the top half of popular items, are both too sensitive to the speed of early adoption and too easy. Most of the predictive power comes from looking at how quickly items reach their first few adopters, while for other features of early adopters and their networks, even the direction of correlation with popularity is not consistent across domains. Problem formulations that examine items that reach k adopters in about the same amount of time reduce the importance of temporal features, but also overall accuracy, highlighting that we understand little about why items become popular while providing a context in which we might build that understanding.
Hilbert modules over a planar algebra and the Haagerup property

Abstract Given a subfactor planar algebra P and a Hilbert P -module of lowest weight 0 we build a bimodule over the symmetric enveloping inclusion associated to P . As an application we prove diagrammatically that the Temperley–Lieb–Jones standard invariants have the Haagerup property. This provides a new proof of a result due to Popa and Vaes.
On the distribution of DNA translocation times in solid-state nanopores: an analysis using Schrödinger’s first-passage-time theory

In this short paper, a correction is made to the recently proposed solution of Li and Talaga to a 1D biased diffusion model for linear DNA translocation, and a new analysis will be given to their data. It was pointed out by us recently that this 1D linear translocation model is equivalent to the one that was considered by Schrodinger for the Ehrenhaft–Millikan measurements on electron charge. Here, we apply Schrodinger’s first-passage-time distribution formula to the data set in Li and Talaga. It is found that Schrodinger’s formula can be used to describe the time distribution of DNA translocation in solid-state nanopores. These fittings yield two useful parameters: the drift velocity of DNA translocation and the diffusion constant of DNA inside the nanopore. The results suggest two regimes of DNA translocation: (I) at low voltages, there are clear deviations from Smoluchowski’s linear law of electrophoresis, which we attribute to the entropic barrier effects; (II) at high voltages, the translocation velocity is a linear function of the applied electric field. In regime II, the apparent diffusion constant exhibits a quadratic dependence on the applied electric field, suggesting a mechanism of Taylor-dispersion effect likely due the electro-osmotic flow field in the nanopore channel. This analysis yields a dispersion-free diffusion constant value of 11.2 nm2 µs-1 for the segment of DNA inside the nanopore, which is in quantitative agreement with the Stokes–Einstein theory. The implication of Schrodinger’s formula for DNA sequencing is discussed.
A fully distributed asynchronous approach for multi-area coordinated network-constrained unit commitment

This paper discusses a consensus-based alternating direction method of multipliers (ADMM) approach to solve the multi-area coordinated network-constrained unit commitment (NCUC) problem in a distributed manner. Due to political and technical difficulties, it is neither practical nor feasible to solve the multi-area coordination problem in a centralized fashion, which requires full access to all the data of individual areas. In comparison, in the proposed fully distributed approach, local NCUC problems of individual areas can be solved independently, and only limited information is exchanged among adjacent areas to facilitate the multi-area coordination. Furthermore, since traditional ADMM can guarantee convergence only for convex problems, this paper discusses several strategies to mitigate oscillations, enhance convergence performance, and derive good-enough feasible solutions, including: (1) a tie-line power-flow-based area coordination strategy is designed to reduce the number of global consensus variables; (2) different penalty parameters ρ are assigned to individual consensus variables and are updated via certain rules during the iterative procedure, which reduces the impact of the initial values of ρ on the convergence performance; (3) heuristic rules are adopted to fix certain unit commitment variables to avoid oscillations during the iterative procedure; and (4) an asynchronous distributed strategy is studied, which solves NCUC subproblems of small areas multiple times and exchanges information with adjacent areas more frequently within one complete run of slower NCUC subproblems of large areas. Numerical cases illustrate the effectiveness of the proposed asynchronous fully distributed NCUC approach, and we investigate key factors that would affect its convergence performance.