Solid-state structure of (+)-phendimetrazine bitartarate,an anorexic drug

The anorexic drug (+)-(2S, 3S, 4S)-phendimetrazine-2R, 3R)-bitartarate crystallized in the orthorhombic space groupP2₁2₁2₁ and at 293 Ka=7.7710(4),b=13.1379(7),c=15.9913(9) Å,V=1632.6(2) ų,Z=4,R(F)=0.062, andR _w (F)=0.026. A chair conformation 2,3-trans-1,4-oxazine ring with equatorially oriented 2-phenyl,3-methyl, andN-methyl substituents was found as predicted by an earlier reported solid-state CP-MAS¹³C-NMR investigation of crystalline (±)-phendimetrazine bitartarate. The O-CH₂-CH₂-N torsion angle of –58.4(6)° in the solid-state agrees nicely with the 56.0(7)° dihedral angle value estimated by¹H NMR spectroscopy for the major (equatorialN-methyl) phendimetrazine mesylate species in CD₂Cl₂ solution. A common solid-state conformational arrangement was found for (+)-phendimetrazine and a series of six other anorexic drugs structurally analogous to (+)-(2S, 3S)-pseudoephedrine. In this arrangement, NCH(Me)CPh has (S)-configuration, there is a (–)-gaucheMe-CH-C-Ph torsion angle, an antiperiplanarN-CH-C-Ph torsion angle, and the phenyl ring approximately eclipses the C-H bond of the attached carbon (e.g., H-C-C_ipso-C_ortho ca. 4° for 2,3-transphendimetrazine). Nonbonded interactions involving the 3-methyl and the 2-phenyl groups open up the H-C-C_ipso-C_ortho angle in a series of solid-state structures containing the epimeric (–)-(2R, 3S)-ephedrine moiety (e.g., ca. 45° for molecular mechanics calculated 2,3-cis-phendimetrazine model).     

The Grothendieck duality theorem via Bousfield's techniques and Brown representability

Grothendieck proved that if is a proper morphism of nice schemes, then has a right adjoint, which is given as tensor product with the relative canonical bundle. The original proof was by patching local data. Deligne proved the existence of the adjoint by a global argument, and Verdier showed that this global adjoint may be computed locally. In this article we show that the existence of the adjoint is an immediate consequence of Brown's representability theorem. 1It follows almost as immediately, by ``smashing' arguments, that the adjoint is given by tensor product with a dualising complex. Verdier's base change theorem is an easy consequence.

     

DNN Intellectual Property Extraction Using Composite Data

As state-of-the-art deep neural networks are being deployed at the core level of increasingly large numbers of AI-based products and services, the incentive for “copying them” (i.e., their intellectual property, manifested through the knowledge that is encapsulated in them) either by adversaries or commercial competitors is expected to considerably increase over time. The most efficient way to extract or steal knowledge from such networks is by querying them using a large dataset of random samples and recording their output, which is followed by the training of a student network, aiming to eventually mimic these outputs, without making any assumption about the original networks. The most effective way to protect against such a mimicking attack is to answer queries with the classification result only, omitting confidence values associated with the softmax layer. In this paper, we present a novel method for generating composite images for attacking a mentor neural network using a student model. Our method assumes no information regarding the mentor’s training dataset, architecture, or weights. Furthermore, assuming no information regarding the mentor’s softmax output values, our method successfully mimics the given neural network and is capable of stealing large portions (and sometimes all) of its encapsulated knowledge. Our student model achieved 99% relative accuracy to the protected mentor model on the Cifar-10 test set. In addition, we demonstrate that our student network (which copies the mentor) is impervious to watermarking protection methods and thus would evade being detected as a stolen model by existing dedicated techniques. Our results imply that all current neural networks are vulnerable to mimicking attacks, even if they do not divulge anything but the most basic required output, and that the student model that mimics them cannot be easily detected using currently available techniques.     

Mind Stuffed with Red Herrings: Why William James’ Critique of the Mind-Stuff Theory Does not Substantiate a Combination Problem for Panpsychism

There is a famous passage in chapter six of James’ Principles of Psychology whose import, many believe, deals a devastating blow to the explanatory aspirations of panpsychism. In the present paper I take a close look at James’ argument, as well as at the claim that it underlies a powerful critique of panpsychism. Apart from the fact that the argument was never aimed at panpsychism as such, I show that it rests on highly problematic assumptions which, if followed to their logical consequences, are just as inedible to contemporary critics of panpsychism as they are to its present-day supporters. Hence, a naïve employment of the argument, as a critique leveled by physicalists against panpsychism, is counterproductive and even self-defeating. After examining the metaphysical shortcomings undermining James’ position (as well as the hasty “refutations” of panpsychism based on it), I conclude with some reflections on what needs to be done in order to obtain a better perspective regarding the explanatory prospects of panpsychism as an alternative approach to mainstream physicalism in the study of conscious phenomena.     

Solid-state structure determination and solution-state NMR characterization of the (2R,4R)/(2S,4S)- and (2R,4S)/(2S,4R)-diastereomers of the agricultural fungicide propiconazole,the (2R,4S)/(2S,4R)-symmetrical triazole constitutional isomer,and a ditriazole analogue

Single-crystal X-ray diffraction analysis was used to determine the structure of a racemic diastereomer of the agricultural fungicide propiconazole [1-(2-(2,4-dichlorophenyl)-4-n-propyl-1,3-dioxolane-2-yl-methyl)-1-H-1,2,4-triazole] and of two by-products (a symmetrical 1,3,4-triazole racemic-constitutional isomer and a propiconazole ditriazole analogue). All three crystalline racemic-diastereomers had (2R,4S)/(2S,4R)-stereochemistry in which then-propyl group was observed in atrans-to-phenyl disposition. Propiconazole (2R,4S)/(2S,4R)-diastereomer gives crystals belonging to the monoclinic space group P2₁,/a, and, at 293 K,a=8.1192(3),b=18.9769(6),c=10.7137(4) å,Β=99.765(3)?,V=1626.8(1) å³, Z=4,R(F)=0.060, andR _w(F)=0.058. The constitutional isomer by-product (2R,4S)/(2S,4R)-1-(2-(2,4-dichlorophenyl)-4-n-pro-pyl-1,3-dioxolane-2-yl-methyl)-1-H-1,3,4-triazole gives crystals belonging to the monoclinic space group P2₁/n, and, at 293 K,a=11.1763(6),b=10.7716(4),c=14.5804(8) å,Β=107.445(4)?,V=1674.6(1) å³, Z=4,R(F)=0.043, andR _w(F)=0.043. The ditriazole byproduct (2R,4S)/(2S,4R)-1-(2-(2-chloro-4-(1,2,4-triazole-1-yl)phenyl)-4-n-propyl-1,3-dioxolane-2-yl-methyl)-1-H-1,2,4-triazole gives crystals belonging to the triclinic space groupP¯ 1, and, at 193 K,a=5.3329(8),b=8.3738(7),c=20.240(2) å, α=84.213(6)?,Β=87.20(1)?,γ=86.23(1)?,V=896.5(2) å³, Z=2,R(F)=0.046, andR _w(F)=0.051. The presence of both propiconazole (2R.4S)- and (2S,4R)-enantiomers enables the formation of a crystalline racemic modification, while the diastereomeric propiconazole (2R,4R)- and (2S,4S)-enantiomers are viscous oils. In the absence of its enantiomorphic partner, the propiconazole (2R,4S)- or (2S,4R)-enantiomers remain as viscous oils rather than form chiral crystals.     

Excited-state intermolecular proton transfer of firefly luciferin V. Direct proton transfer to fluoride and other mild bases

We studied the direct proton transfer (PT) from electronically excited D-luciferin to several mild bases. The fluorescence up-conversion technique is used to measure the rise and decay of the fluorescence signals of the protonated and deprotonated species of D-luciferin. From a base concentration of 0.25 M or higher the proton transfer rates to the fluoride, dihdyrogen phosphate or acetate bases are fast and comparable. The fluorescence signals are nonexponential and complex. We suggest that the fastest decay component arises from a direct proton transfer process from the hydroxyl group of D-luciferin to the mild base. The proton donor and acceptor molecules form an ion pair prior to photoexcitation. Upon photoexcitation solvent rearrangement occurs on a 1 ps time-scale. The PT reaction time constant is ～2 ps for all three bases. A second decay component of about 10 ps is attributed to the proton transfer in a contact pair bridged by one water molecule. The longest decay component is due to both the excited-state proton transfer (ESPT) to the solvent and the diffusion-assisted PT process between a photoacid and a base pair positioned remotely from each other prior to photoexcitation.     

Excited-state intermolecular proton transfer of firefly luciferin IV. Temperature and pH dependence

Time-resolved emission as well as steady-state UV-vis techniques were employed to study the photoprotolytic processes that d-luciferin, the natural substrate of the firefly luciferase, undergoes in both acidic aqueous solutions and ice. The emission spectrum of D-luciferin in a 20 mM HCl aqueous solution or higher has an additional emission band at 590 nm red-shifted with respect to the strongest emission band positioned at 530 nm of the deprotonated NRO(-*) form in a pH-neutral aqueous solution. We attribute this emission band to the zwitterion form designated as (+)HNRO(-). The time-resolved emission signals show that the NRO(-*) emission band at 530 nm and the zwitterion emission band at 590 are strongly quenched by a recombination process with a proton in an acidic solution and in ice. In ice, the quenching rate is 10 times faster than in the liquid state. We attribute the fast quenching rate to the high value of the proton diffusion constant in ice.     

Brown representability for the dual

Let T be the homotopy category of all spectra. Brown proved that a homological functor H: T ^{o p} → Ab is representable if it takes coproducts to products. That is, the functors [−,h] may be characterised as the homological functors taking coproducts to products. In this article, we will prove the dual. A covariant functor H:T → Ab which takes products to products is representable; it is of the form [h,−]. Oblatum 10-VII-1997 & 23-VII-1997