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The majority of Multi-Agent Reinforcement Learning (MARL) literature equates the cooperation of self-interested agents in mixed environments to the problem of social welfare maximization, allowing agents to arbitrarily share rewards and private information. This results in agents that forgo their individual goals in favour of social good, which can potentially be exploited by selfish defectors. We argue that cooperation also requires agents' identities and boundaries to be respected by making sure that the emergent behaviour is an equilibrium, i.e., a convention that no agent can deviate from and receive higher individual payoffs. Inspired by advances in mechanism design, we propose to solve the problem of cooperation, defined as finding socially beneficial equilibrium, by using mediators. A mediator is a benevolent entity that may act on behalf of agents, but only for the agents that agree to it. We show how a mediator can be trained alongside agents with policy gradient to maximize social welfare subject to constraints that encourage agents to cooperate through the mediator. Our experiments in matrix and iterative games highlight the potential power of applying mediators in MARL.

Contract design involves a principal who establishes contractual agreements about payments for outcomes that arise from the actions of an agent. In this paper, we initiate the study of deep learning for the automated design of optimal contracts. We formulate this as an offline learning problem, where a deep network is used to represent the principal's expected utility as a function of the design of a contract. We introduce a novel representation: the Discontinuous ReLU (DeLU) network, which models the principal's utility as a discontinuous piecewise affine function where each piece corresponds to the agent taking a particular action. DeLU networks implicitly learn closed-form expressions for the incentive compatibility constraints of the agent and the utility maximization objective of the principal, and support parallel inference on each piece through linear programming or interior-point methods that solve for optimal contracts. We provide empirical results that demonstrate success in approximating the principal's utility function with a small number of training samples and scaling to find approximately optimal contracts on problems with a large number of actions and outcomes.

In this work, we present a new benchmarking suite with new real-life inspired skewed workloads to test the performance of concurrent index data structures. We started this project to prepare workloads specifically for self-adjusting data structures, i.e., they handle more frequent requests faster, and, thus, should perform better than their standard counterparts. We looked over the commonly used suites to test performance of concurrent indices trying to find an inspiration: Synchrobench, Setbench, YCSB, and TPC - and we found several issues with them. The major problem is that they are not flexible: it is difficult to introduce new workloads, it is difficult to set the duration of the experiments, and it is difficult to change the parameters. We decided to solve this issue by presenting a new suite based on Synchrobench. Finally, we highlight the problem of measuring performance of data structures. We show that the relative performance of data structures highly depends on the workload: it is not clear which data structure is best. For that, we take three state-of-the-art concurrent binary search trees and run them on the workloads from our benchmarking suite. As a result, we get six experiments with all possible relative performance of the chosen data structures.

Objective: To study burnout of Russian physicians in the conditions of COVID-19 pandemic and how their work with coronavirus-infected patients influenced it. According to a three-factor model of burnout developed by Maslach and Jackson, this syndrome includes emotional exhaustion, depersonalization, and reduction of personal accomplishment. Design: A cross-sectional survey study. Setting: Large medical practice. Participants: Physicians of different specialties. Methods: Data collection was conducted from June 23 to July 12, 2020. We developed a Google form including a questionnaire and psychological inventories and placed it in a medical portal. Maslach Burnout Inventory — Human Services Survey for Medical Personnel was used to study burnout; the Hospital Anxiety and Depression Scale was used to determine anxiety and depression. Results: Of all the physicians who took part in the study (N = 599), 31.2 % worked with coronavirus-infected patients. Of the medical personnel who treated COVID-19 patients, 63.6% noted increased workload during the pandemic. Compared to other physicians, they more often had a high degree of emotional exhaustion (43.3 % vs 33.0 %, φ* = 2.404, P ≤ 0.01) and depersonalization (41.7 % vs 34, 0%, φ* = 1.803, P ≤ 0.05). An overwhelming majority of physicians, without any dependence on work with infected patients, had an absence of anxiety and depression. The identified interrelations between the symptoms of burnout, anxiety, depression; age and career stage in medical personnel were identical, except for weak correlations between age and emotional exhaustion (rs = -0.097, P ≤ 0.05), as well as career stage and personal accomplishment (rs = 0.102, P ≤ 0.05) in those physicians who worked with COVID-19 patients. The structure of burnout was identical in all physicians and did not depend on interaction with the infected patients. Conclusion: Public health authorities should reduce the workload on physicians involved in treating infected patients against the backdrop of the pandemic. Psychotherapeutic measures focused on preventing burnout should reduce its number among physicians interacting with patients infected with the coronavirus.

Modern artificial intelligence (AI) systems, based on von Neumann architecture and classical neural networks, have a number of fundamental limitations in comparison with the mammalian brain. In this article we discuss these limitations and ways to mitigate them. Next, we present an overview of currently available neuromorphic AI projects in which these limitations are overcome by bringing some brain features into the functioning and organization of computing systems (TrueNorth, Loihi, Tianjic, SpiNNaker, BrainScaleS, NeuronFlow, DYNAP, Akida, Mythic). Also, we present the principle of classifying neuromorphic AI systems by the brain features they use: connectionism, parallelism, asynchrony, impulse nature of information transfer, on-device-learning, local learning, sparsity, analog, and in-memory computing. In addition to reviewing new architectural approaches used by neuromorphic devices based on existing silicon microelectronics technologies, we also discuss the prospects for using a new memristor element base. Examples of recent advances in the use of memristors in neuromorphic applications are also given.

Ripple effect is a specific area of SC disruptions and a strong stressor to SC resilience. Research on the ripple effect analyses how one or more disruptive events propagate through the SC and impa...

The COVID-19 pandemic has created significant uncertainty in all areas of life, including supply chains (SCs). This paper presents a new risk-averse mixed-integer nonlinear problem mathematical model for the design and planning of a two-echelon resilient SC network. Disruption events, which can partially or completely reduce the available capacity, are included in the model. The model’s objective is to minimise the total costs by determining the optimal facility location and capacity, allocation flows and resilience actions for hedging against disruption risk. A solution procedure is tested through computational experiments, and managerial insights were formed based on a numerical example for several disruption configurations, with a specific case of long-term crises similar to the COVID-19 pandemic. The results showed that recovery activities are the most efficient actions to take for a short-term disruption event. Besides, proactive resilience investment in a protection system and flexibility enhancement allows the SC to handle the disruption period with a limited increase in network building costs and overcapacity.

This article proposes a sparse computation-based method for optimizing neural networks for reinforcement learning (RL) tasks. This method combines two ideas: neural network pruning and taking into account input data correlations; it makes it possible to update neuron states only when changes in them exceed a certain threshold. It significantly reduces the number of multiplications when running neural networks. We tested different RL tasks and achieved 20-150x reduction in the number of multiplications. There were no substantial performance losses; sometimes the performance even improved.

Despite the numerous breakthroughs achieved with Reinforcement Learning (RL), solving environments with sparse rewards remains a challenging task that requires sophisticated exploration. Learning from Demonstrations (LfD) remedies this issue by guiding the agent's exploration towards states experienced by an expert. Naturally, the benefits of this approach hinge on the quality of demonstrations, which are rarely optimal in realistic scenarios. Modern LfD algorithms require meticulous tuning of hyperparameters that control the influence of demonstrations and, as we show in the paper, struggle with learning from suboptimal demonstrations. To address these issues, we extend Self-Imitation Learning (SIL), a recent RL algorithm that exploits the agent's past good experience, to the LfD setup by initializing its replay buffer with demonstrations. We denote our algorithm as SIL from Demonstrations (SILfD). We empirically show that SILfD can learn from demonstrations that are noisy or far from optimal and can automatically adjust the influence of demonstrations throughout the training without additional hyperparameters or handcrafted schedules. We also find SILfD superior to the existing state-of-the-art LfD algorithms in sparse environments, especially when demonstrations are highly suboptimal.

We present a new study on helicity amplitudes and cross sections for the exclusive production of $ρ$ mesons at the EIC in high-energy factorization. In this framework the analytic expression of amplitudes takes the form of a convolution between an off-shell impact factor, depicting the ($γ^* \to ρ$) transition, and a nonperturbative density, known as Unintegrated Gluon Distribution (UGD) that encodes information about the proton structure at low $x$ and evolves according to the BFKL equation. We come out with an evidence that observables sensitive to the polarizations of the incoming virtual photon and of the emitted meson allow us to discriminate among different UGD models and to gather quantitative information on the proton content at high energies., 6 pages, 1 figure. Presented by F.G. Celiberto at DIS2022: XXIX International Workshop on Deep-Inelastic Scattering and Related Subjects, Santiago de Compostela, Spain, May 2-6 2022

The coronavirus (COVID-19) outbreak shows that pandemics and epidemics can seriously wreak havoc on supply chains (SC) around the globe. Humanitarian logistics literature has extensively studied epidemic impacts; however, there exists a research gap in understanding of pandemic impacts in commercial SCs. To progress in this direction, we present a systematic analysis of the impacts of epidemic outbreaks on SCs guided by a structured literature review that collated a unique set of publications. The literature review findings suggest that influenza was the most visible epidemic outbreak reported, and that optimization of resource allocation and distribution emerged as the most popular topic. The streamlining of the literature helps us to reveal several new research tensions and novel categorizations/classifications. Most centrally, we propose a framework for operations and supply chain management at the times of COVID-19 pandemic spanning six perspectives, i.e., adaptation, digitalization, preparedness, recovery, ripple effect, and sustainability. Utilizing the outcomes of our analysis, we tease out a series of open research questions that would not be observed otherwise. Our study also emphasizes the need and offers directions to advance the literature on the impacts of the epidemic outbreaks on SCs framing a research agenda for scholars and practitioners working on this emerging research stream.

We theorize a notion of a digital supply chain (SC) twin – a computerized model that represents network states for any given moment in real time. We explore the conditions surrounding the design an...

International audience; An intertwined supply network (ISN) is an entirety of interconnected supply chains (SC) which, in their integrity secure the provision of society and markets with goods and services. The ISNs are open systems with structural dynamics since the firms may exhibit multiple behaviors by changing the buyer-supplier roles in interconnected or even competing SCs. From the positions of resilience, the ISNs as a whole provide services to society (e.g., food service, mobility service or communication service) which are required to ensure a long-term survival. The analysis of survivability at the level of ISN requires a consideration at a large scale as resilience of individual SCs. The recent example of coronavirus COVID-19 outbreak clearly shows the necessity of this new perspective. Our study introduces a new angle in SC resilience research when a resistance to extraordinary disruptions needs to be considered at the scale of viability. We elaborate on the integrity of the ISN and viability. The contribution of our position study lies in a conceptualization of a novel decision-making environment of ISN viability. We illustrate the viability formation through a dynamic game-theoretic modelling of a biological system that resembles the ISN. We discuss some future research areas.

International audience; In this paper, we introduce cloud supply chain which is a business model based on cloud-enabled networking of some third-party physical and digital assets to design and manage a supply chain network. Cloud supply chain integrates concepts and technology of Industry 4.0 and digital platforms emerging in the “supply chain-as-a-service” paradigm. This paper conceptualizes the cloud supply chain as a new and distinct research area. Through analysis of practical cases, we deduce some generalized characteristics of the cloud supply chain. In the generalised model, we formalize supply chain multi-structural dynamics and dynamic service composition. Our results show that the main generalized characteristics of the cloud supply chain are related to (i) multi-structural dynamics; (ii) platforms, digital supply chains, ecosystems, and visibility, (iii) dynamic service composition with dynamically changing buyer/supplier roles, (iv) resilience and viability, and (v) intertwined supply networks and circular economy. We close by discussing future research directions including novel context of Industry 5.0.

The article is an overview of the virtual meeting of researchers who are developing critical theory of society in different forms and in different countries. Restrictions on social activities in the period of COVID-19 pandemics have impacted (among other social structures and interactions) academic exchanges and scientific communications. Overcoming the routine of digital substitutes for traditional academic community life, the participants of the new scientific event contributed intensively to dialectical discourse of oppression and emancipation. The global roundtable was organized around 9 main presentations made by leading critical theorists. Preserving basic ideas from the Frankfurt school and other lines of Marxism and neo-Marxism, critical theorists are working to open new sources for development of rational and at the same time humanist and contextualized critique of new forms of alienation (including digital one) and new forms of oppression (including neo-colonialist one). Participants of the global roundtable have shared idea of permanent reflection aimed at continuation of the critical theorizing and at the emancipation of human beings., Статья представляет обзор виртуальной встречи исследователей, развивающих критическую теорию общества в различных формах в разных странах. Ограничения, налагаемые на социальную деятельность в период распространения вируса COVID-19, оказали воздействие на все социальные структуры и взаимодействия, включая академические обмены и научную коммуникацию. Преодолевая рутину цифровых заменителей традиционной жизни академического сообщества, участники нового научного мероприятия существенно развили диалектический дискурс подавления и эмансипации. Глобальный круглый стол был организован вокруг девяти основных докладов ведущих теоретиков. Сохраняя базовые идеи Франкфуртской школы и других марксистских и неомарксистских течений, теоретики работают над открытием новых источников для развития рациональной и в то же время гуманистической и контекстуализированной критики новых форм отчуждения (включая цифровое) и новых форм подавления (включая неоколониализм). Участники глобального круглого стола разделяют идею перманентной рефлексии, нацеленной на продолжение критической рефлексии и на эмансипацию людей от новых форм порабощения.

The Flatland competition aimed at finding novel approaches to solve the vehicle re-scheduling problem (VRSP). The VRSP is concerned with scheduling trips in traffic networks and the re-scheduling of vehicles when disruptions occur, for example the breakdown of a vehicle. While solving the VRSP in various settings has been an active area in operations research (OR) for decades, the ever-growing complexity of modern railway networks makes dynamic real-time scheduling of traffic virtually impossible. Recently, multi-agent reinforcement learning (MARL) has successfully tackled challenging tasks where many agents need to be coordinated, such as multiplayer video games. However, the coordination of hundreds of agents in a real-life setting like a railway network remains challenging and the Flatland environment used for the competition models these real-world properties in a simplified manner. Submissions had to bring as many trains (agents) to their target stations in as little time as possible. While the best submissions were in the OR category, participants found many promising MARL approaches. Using both centralized and decentralized learning based approaches, top submissions used graph representations of the environment to construct tree-based observations. Further, different coordination mechanisms were implemented, such as communication and prioritization between agents. This paper presents the competition setup, four outstanding solutions to the competition, and a cross-comparison between them., Comment: 28 pages, 8 figures

We calculate cross sections for the exclusive diffractive leptoproduction of $��$-mesons, $��^*~p~\to~��~p$, within the framework of high-energy factorization. Cross sections for longitudinally and transversally polarized mesons are shown. We employ a wide variety of unintegrated gluon distributions available in the literature and compare to HERA data. The resulting cross sections strongly depend on the choice of unintegrated gluon distribution. We also present predictions for the proton target in the kinematics of the Brookhaven EIC., 21 pages, 8 figures. arXiv admin note: text overlap with arXiv:1808.02395; version published in Eur. Phys. J. C

We present a study on inclusive emissions of a double $��_c$ or of a $��_c$ plus a light-flavored jet system as probe channels in the semi-hard regime of QCD. Our formalism relies on the so-called hybrid high-energy/collinear factorization, where the standard collinear description is supplemented by the $t$-channel resummation �� la BFKL of energy logarithms up to the next-to-leading accuracy. We make use of the JETHAD modular interface, suited to the analysis of different semi-hard reactions, employing the novel KKSS19 parameterization for the description of parton fragmentation into $��_c$ baryons. We provide predictions for rapidity distributions and azimuthal correlations, that can be studied at current and forthcoming LHC configurations, hunting for possible stabilizing effects of the high-energy series., 28 pages, 9 figures; updated references, version published in Eur. Phys. J. C

We propose the study of the inclusive production of two $��$ hyperons or a single $��$-particle in association with a jet, featuring high transverse momenta and large separation in rapidity, as a probe channel of the resummation of energy logarithms in the QCD perturbative series. We give predictions, shaped on kinematic ranges typical of CMS and of the backward CASTOR detector, for cross section and azimuthal-correlation moments between the two emitted objects, showing how considering the tag of $��$ baryons eases the comparison between theoretical results and experimental data in the phenomenological context of semi-hard reactions., 23 pages, 6 figures; updated references; slight changes in Eq. (14), updated Section 2.3, added 2 plots (Figs. 6 and 8), version published in Phys. Rev. D

The article studies the issues of rock culture as a specific open discourse system being a part of the Russian national culture. The article aims to identify the most promising ways for comprehensive analysis of this phenomenon in the context of modern humanitarian knowledge. The terms “cultural studies”, “discourse”, “synthetic text”, and “rock text” are specified. The article addresses a rock text and rock poetry at the present stage of humanitarian knowledge development; components determining the nature of the rock text compared to other poetic texts; a method that can describe the rock text as a complex synthetic phenomenon. The research purpose is to study the Russian rock culture in terms of modern humanitarian knowledge. The following methods were used: comparative, integrated, statistical, and linguocultural analysis. The article concludes that the rock work is closely associated with poetry, melody, musical rhythm, vocal, audience factor, and stage behavior. It can be considered as a synthetic phenomenon. The rock text cannot be interpreted and studied within narrow disciplines. Its nature and configuration cannot be the subject of individual scientific disciplines. Such large-scale, developing, holistic cultural phenomenon can be studied only within cultural disciplines with their specific methods. In particular, linguoculturological and culturological methods can be combined to study this phenomenon.

The gluon content of the proton, in the high-energy regime, is embodied by the unintegrated gluon distribution (UGD), which describes the gluon emission probability, with a given longitudinal momentum fraction and transverse momentum. The UGD, formulated within the $��$-factorization approach, has universal validity and several models for it have been proposed so far. We will show that the polarized $��$-meson leptoproduction at HERA is a not trivial testfield for discriminating among existing models of UGD., 6 pages, 4 figures, presented by A.D. Bolognino at "Diffraction & Low-x 2018", Reggio Calabria, Italy, August 26 - September 1, 2018; to be published in the conference proceedings by Acta Phys. Polon. B

The gluon content of the proton is embodied by the unintegrated gluon distribution (UGD), which has universal validity. In literature many models of UGD have been proposed so far. The polarized $��$-meson leptoproduction at HERA offers a nowadays unexplored testfield to discriminate among existing models of UGD, via the comparison with theoretical predictions formulated in the $��$-factorization approach., 6 pages, 3 figures, Talk given at the XIX Frascati Spring School "Bruno Touschek" in nuclear, subnuclear and astroparticle physics, Frascati, 7-11 May 2018

We present here some arguments to support our suggestion that data on the helicity structure for the hard exclusive electroproduction of $��$ mesons at HERA (and in possible future high-energy electron-proton colliders) provide useful information to constrain the $��$-shape of the unintegrated gluon distribution in the proton., 20 pages, 4 figures; version accepted for publication on Eur. Phys. J. C

The production of forward jets separated by a large rapidity gap at LHC, the so-called Mueller-Navelet jets, is a fundamental testfield for perturbative QCD in the high-energy limit. Several analyses have already provided with evidence about the compatibility of theoretical predictions, based on collinear factorization and BFKL resummation of energy logarithms in the next-to-leading approximation, with the CMS experimental data at 7 TeV of center-of-mass energy. However, the question if the same data can be described also by fixed-order perturbative approaches has not been yet fully answered. In this paper we provide numerical evidence that the mere use of partially asymmetric cuts in the transverse momenta of the detected jets allows a clear separation between BFKL-resummed and fixed-order predictions in some observables related with the Mueller-Navelet jet production process., Comment: 15 pages, 3 figures, 2 tables; slight change in the title; version to appear on Eur. Phys. J. C. arXiv admin note: text overlap with arXiv:1407.8431

The BFKL approach for the investigation of semihard processes is plagued by large next-to-leading corrections, both in the kernel of the universal BFKL Green's function and in the process-dependent impact factors, as well as by large uncertainties in the renormalization scale setting. All that calls for some optimization procedure of the perturbative series. In this respect, one of the most common methods is the Brodsky-Lepage-Mackenzie (BLM) one, that eliminates the renormalization scale ambiguity by absorbing the non-conformal $\beta_0$-terms into the running coupling. In this paper, we apply BLM scale setting procedure directly to the amplitudes (cross sections) of several semihard processes. We show that, due to the presence of $\beta_0$-terms in the next-to-leading expressions for the impact factors, the optimal renormalization scale is not universal, but depends both on the energy and on the type of process in question., Comment: 21 pages, 4 figures; added a few sentences and two references in the Summary section; version accepted for publication by Phys. Rev. D

We study the total cross section for the collision of two highly-virtual photons at large energies, taking into account the BFKL resummation of energy logarithms with full next-to-leading accuracy. A necessary ingredient of the calculation, the next-to-leading order impact factor for the photon to photon transition, has been calculated by Balitsky and Chirilli using an approach based on the operator expansion in Wilson lines. We extracted the result for the photon impact factor in the original BFKL calculation scheme comparing the expression for the photon-photon total cross section obtained in BFKL with the one recently derived by Chirilli and Kovchegov in the Wilson-line operator expansion scheme. We perform a detailed numerical analysis, combining different, but equivalent in next-to-leading accuracy, representations of the cross section with various optimization methods of the perturbative series. We compare our results with previous determinations in the literature and with the LEP2 experimental data. We find that the account of Balitsky and Chirilli expression for the photon impact factor reduces the BFKL contribution to the cross section to very small values, making it impossible to describe LEP2 data as the sum of BFKL and leading-order QED quark box contributions., 20 pages, 8 figures; two sentences and some references added, a few typos removed; version to be published on JHEP

We study the $��^* ��^*$ total cross section in the NLA BFKL approach. We have extracted the NLO corrections to the photon impact factor from two recent papers of Balitsky and Chirilli and Chirilli and Kovchegov and used them to build several representations of the total cross section, equivalent within the NLA. We have combined these different representations with two among the most common methods for the optimization of a perturbative series, namely PMS and BLM, and compared their behavior with the energy with the only available experimental data, those from the LEP2 collider., 4 pages, 2 figures; presented at "Diffraction 2014", Primosten, Sept. 10-16, 2014

We calculate in next-to-leading order BFKL the jet vertex relevant for the production of Mueller-Navelet jets in proton collisions and of forward jets in deep inelastic scattering. Starting from the definition of the totally inclusive quark and gluon impact factors in the BFKL approach and suitably considering the parton densities and the jet selection functions, we show that an infrared-free result can be found for the jet vertex. Finally we compare our expression for the vertex with the previous calculation of Refs. 1., Comment: 6 pages; presented at the 3rd Young Researchers Workshop "Physics Challenges in the LHC Era", Frascati, May 7 and 10, 2012

Spathoderma bulbosum n. sp. (Figures 1E, 19, 20, 23A, B, 24A, 25; Tables 1–3a, 4a, b) Type material: Holotype USNM 1112620. Paratypes: USNM; TAMU; ZMUM Le1–171 (DGoMB C4/1). Type locality: Gulf of Mexico, 28°16.78'N, 87°20.10'W, 2,627 m (DGoMB stn. S38 rep. 3, 14.06.2000). Material examined: Off North Carolina, 1 specimen (Table 3a); Gulf of Mexico, 89 specimens (Table 1); Guiana Basin, 9 specimens (Table 4a); and from off Recife, 6 specimens (Table 4b). Diagnosis: Small, to 2.3 mm, opaque, widest anteriorly (bulbous), tapering posteriorly with no clear demarcation between trunk and shank in most specimens, posterium length 1/3–1/2 trunk length; without distinct fringe at knob but with clusters of long sclerites protruding from knob,>2 times length of knob. Sclerites large, thick relative to body size; bases adpressed, longer on shank than trunk. Oral shield sclerites in 3 rows. Etymology: L. bulbus & Greek bolbos, L. bulbosus -a, -um = a swelling. Description: External appearance (Figs 1E, 19A, B): Length to 2.3 mm, width to 0.7 mm anteriorly; when able to distinguish shank from trunk, posterium/trunk index appears to be 0.35 to almost 0.50; holotype length 2.3 mm, anterium 0.1 mm, trunk 1.5 x 0.7 mm wide anteriorly, gradually tapering to Sclerites (Figs 19G, 20, 23A, B): General: large, blade bent outwards at waist (Fig. 20K), length increasing regularly posteriorly to nearly 400 µm on shank, and thick, to nearly 10 µm, proximally rounded, distally with sharp point; except for size, morphologically similar from anterior trunk to knob, with blade length increasing from ~1/2 base length to equal to base length; thickest medially either on base at waist or crossing from base onto blade; axis straight (Fig. 19G), but rotation of blade from plane of base gives appearance of an abrupt change in direction of axis at waist (Fig. 20). Isochromes appearing asymmetrical owing to rotation; blade and base with fine, irregularly spaced longitudinal striations (Fig. 23B). Oral shield (Fig. 20A): ovoid with one side concave, without distal point, thick, to 70 x 30 x 7 µm, thickest proximally. Dorsal to oral shield (Fig. 20B): thin, pointed scales Anterium (Fig. 20C): either short, broad, with very short blade, to 80 x 30 x 2 µm, or narrow, slightly curved, with distinct waist almost in middle of sclerite, blade width equal to base width, to 90 x 20 x 3, thickest at mid-base. Ventral anterior trunk (Fig. 20D): similar to narrow anterium sclerites but larger, 120 x 25–30 x> 10 µm. Dorsal trunk and lateral (Figs 19G, 20E, G): as in general description, ranging from 80 x 40 x> 10 µm to>300 x 60 x 9 µm, with blade lengths ~1/2 to equal to base length. Ventral trunk (Fig. 20F): most shorter, but not much narrower, than those from dorsal trunk. Shank (Fig. 20H): similar to those from dorsal trunk with same base length but thinner and with longer blade equal to or longer than base, to 380 x 75 x 7, thickest near waist. Fringing: lacking; shank sclerites covering proximal part of knob. Knob: two types: short, tapered proximally and distally, straight except proximal end with slight curve (Fig. 20I), and very long clusters, 360 x 30 x 7 µm (Fig. 20J). Radula and jaws: 1 examined. Jaws 570 x 275 µm (Fig. 19E); radula teeth 120 µm long, serrated membrane about 70 µm, medial to distal; central plate almost symmetrical, curved, to 50 µm (Fig. 19F). Distribution: Continental slope and rise: off North Carolina ~ 850 m; Gulf of Mexico 622–3,000 m; Guiana Basin 2,487 –2,842 m; and off Recife 943 m (Tables 1–3a, 4a, b) (Figs. 24A, 25). Remarks: Spathoderma bulbosum is distinguished from most Atlantic species of Spathoderma by the bulbous anterior trunk, indistinct demarcation between trunk and shank, knob with clusters of long sclerites, and very thick mid-trunk sclerites in comparison to their length. It can be confused with S. quadratum, however, particularly juvenile specimens; see Remarks under S. quadratum., Published as part of Ivanov, Dmitry L. & Scheltema, Amélie H., 2008, NMR solution structures of KAP- 1 PHD finger-bromodomain, pp. 1-60 in Zootaxa 1885 on pages 30-33, DOI: 10.13018/bmr11036, http://zenodo.org/record/5133706

Ivanov, Dmitry L., Scheltema, Amélie H. (2008): NMR solution structures of KAP-1PHD finger-bromodomain. Zootaxa 1885: 1-60, DOI: 10.13018/bmr11036, URL: http://dx.doi.org/10.13018/bmr11036

Prochaetoderma Thiele, 1902 Thiele, 1902: 275. Type species: Chaetoderma raduliferum Kowalevsky, 1901 (monotypy). Diagnosis: Sclerites adpressed, parallel to longitudinal body axis on trunk and posterium or only on posterium. Planes of sclerite base and blade flat, or blade slightly curved towards body (Fig. 17J); base and blade not obviously offset or at an angle to each other or rotated relative to each other. Longitudinal axis straight, isochromes symmetrical or nearly so. Waist indentation shallow, sometimes indistinct. Blade with short or long medial keel, edges straight or more usually convex, blade width about same width as base at waist. Oral shield sclerites in two rows. Distribution: Eastern and western north and south Atlantic including south of Iceland, Mediterranean Sea, Arabian Sea, eastern and western Pacific, continental shelf to continental rise, 50 to 2,895 m depth (Kowalevsky 1901, Scheltema 1985, Salvini-Plawen 1997, Scheltema & Ivanov 2000, Ivanov & Scheltema 2002, Salvini-Plawen & Öztürk 2006; including unpublished data). Composition: P. arabicum Ivanov & Scheltema, 2002; P. (?) atlanticum Scheltema & Ivanov, 2000; P. boucheti Scheltema & Ivanov, 2000; P. gilrowei n. sp.; P. raduliferum (Kowalevsky, 1901); P. yongei Scheltema, 1985., Published as part of Ivanov, Dmitry L. & Scheltema, Amélie H., 2008, NMR solution structures of KAP- 1 PHD finger-bromodomain, pp. 1-60 in Zootaxa 1885 on pages 25-26, DOI: 10.13018/bmr11036, http://zenodo.org/record/5133706, {"references":["Kowalevsky, A. (1901) Sur le genre Chaetoderma. Archives de Zoologie experimental & general, ser. 3, 9, 261 - 284.","Scheltema, A. H. (1985) The Aplacophoran family Prochaetodermatidae in the North American Basin, including Chevroderma n. g. and Spathoderma n. g. (Mollusca; Chaetodermomorpha). Biological Bulletin, 169, 484 - 529.","Salvini-Plawen, L. v. (1997) Fragmented knowledge on West-European and Iberian Caudofoveata and Solenogastres. Iberus, 15, 35 - 50.","Scheltema, A. H. & Ivanov, D. L. (2000) Prochaetodermatidae of the Eastern Atlantic Ocean and Mediterranean Sea (Mollusca, Aplacophora). Journal of Molluscan Studies, 66, 313 - 362.","Ivanov, D. L. & Scheltema, A. H. (2002) Prochaetodermatidae of the Indian Ocean collected during Soviet VITYAZ cruises 1959 - 1964 (Mollusca: Aplacophora). Molluscan Research, 22, 183 - 202.","Salvini-Plawen, L. v. & Ozturk, B. (2006) New records of Caudofoveata (Falcidens gutturosus, Prochaetoderma raduliferum) and of Solenogastres (Eleutheromenia carinata, spec. nov.) from the eastern Mediterranean Sea (Mollusca). Spixiana, 29, 217 - 224."]}

Chevroderma Scheltema, 1985 Scheltema, 1985: 512. Type species: Chevroderma turnerae Scheltema, 1985 (OD). Diagnosis (emended): Sclerites with a usually distinct, but sometimes faint, medial groove extending part way or entire length of sclerite. Growth lines and base of sclerites chevron-shaped. Plane of sclerite blade bent outwards from plane of base; or blade reduced to a sharp, raised nipple. Longitudinal axis straight or bent at waist. Waist usually distinct, blade narrower than base at waist, edges of blade nearly straight and tapered. Isochromes on each side of groove asymmetrical, thickest beside groove. Two rows of oral shield sclerites. Distribution: Species have been found in most of the world's oceans: eastern and western north and south Atlantic including the Gulf of Mexico, eastern and western Indian Ocean, eastern and western north and south Pacific, and central north Pacific; the genus has not been found in the Mediterranean Sea. The shallowest depth recorded is 357 m (herein for Ch. cuspidatum n. sp.); the deepest, for Ch. hadalis Ivanov, is 8,390 m in the Kurile-Kamchatka Trench. Only new species described here occur at continental slope depths; all other Chevroderma species have been found at continental rise, abyssal, and hadal depths (Scheltema, 1985; Ivanov, 1996; Ivanov & Scheltema, 2001a, 2002; including unpublished data). Composition: Ch. cuspidatum n. sp., Ch. gauson Scheltema, 1985, Ch. hadalis Ivanov, 1996, Ch. javanicum Ivanov & Scheltema, 2002, Ch. lusae Ivanov & Scheltema, 2002, Ch. paradoxum Ivanov & Scheltema, 2001, Ch. scalpellum Scheltema, 1985, Ch. turnerae Scheltema, 1985, Ch. vityazi Ivanov & Scheltema, 2002, and Ch. whitlachi Scheltema, 1985 (Panama Basin only)., Published as part of Ivanov, Dmitry L. & Scheltema, Amélie H., 2008, NMR solution structures of KAP- 1 PHD finger-bromodomain, pp. 1-60 in Zootaxa 1885 on page 5, DOI: 10.13018/bmr11036, http://zenodo.org/record/5133706, {"references":["Scheltema, A. H. (1985) The Aplacophoran family Prochaetodermatidae in the North American Basin, including Chevroderma n. g. and Spathoderma n. g. (Mollusca; Chaetodermomorpha). Biological Bulletin, 169, 484 - 529.","Ivanov, D. L. (1996) Chevroderma hadalis, a new species of Prochaetodermatidae (Caudofoveata, Aplacophora) from the North-west Pacific. Ruthenica, 6, 83 - 84","Ivanov, D. L. & Scheltema, A. H. (2001 a) Prochaetodermatidae of the Western Indian Ocean and Arabian Sea (Mollusca: Aplacophora). In: Bouchet, P. & Marshall, B. A. (Eds), Tropical Deep-Sea Benthos 22. Memoires du Museum National d'Histoire Naturelle, 185, 10 - 38","Ivanov, D. L. & Scheltema, A. H. (2002) Prochaetodermatidae of the Indian Ocean collected during Soviet VITYAZ cruises 1959 - 1964 (Mollusca: Aplacophora). Molluscan Research, 22, 183 - 202."]}

Prochaetoderma gilrowei n. sp. (Figures 1G, 16, 17, 18D–F, 24C, 25; Tables 1, 2, 4a) Type material: Holotype USNM 1112619. Paratypes: USNM; TAMU; ZMUM Le1–156 (DGoMCS 4447, station E2b/3); Le1–157 (DGoMB S35/3). Type locality: Gulf of Mexico, 28°15.16'N, 86°25.07'W, 767 m (DGoMB S42/1, 09.06.2000). Material examined: Gulf of Mexico, 159 specimens (Table 1); Guiana Basin, 60 specimens (Table 4a). Diagnosis: Small (Etymology: Named in honor of Dr. Gilbert Rowe, who provided us with much of the Gulf of Mexico material reported here. Description: External appearance: Small, to 1.8 mm, many Sclerites (Figs 16E, 17, 18D–F): General: Short, thin, symmetrical, less than 170 µm long, 5 µm thick, longitudinal axis to somewhat curved (Figs 17J, 18D, E), waist indented, blade narrower than base, thickest at waist and blade, sides of base convex, of blade straight to convex, proximally rounded, distally sharply pointed; keel on blade with fine, sharp ridges, base striated (Fig. 18D, F). Oral shield (Fig. 17A): straight to curved, tapered basally, thick, to 50 x 15 x 4 µm, thickest proximally. Dorsal to oral shield (Fig. 17B): very thin scales, most sub-triangular, to 45 x 30 x Anterium (Fig. 17C): either short with curved, narrow base, or with distinct waist, blade and base almost equal in length, to 100 x 30 x 3 µm, blade narrower than base. Dorsal trunk (Figs 16E, 17F, 18D, E): as in general description, to 160 x 45 x 5 µm, thickest on keel near waist, blade and base width 30 and 45 µm, respectively. Ventral and lateral trunk (Fig. 17D, E): similar to those from dorsal trunk, but most shorter and narrower. Shank (Fig. 17G): either broad-based with short blade, 110 x 45 µm, or with narrower base and elongate blade, to 160 x 35 µm, both types thickest on blade. Fringing (Fig. 17I): long and slightly curved, to 500 x 8 x 8 µm. Knob (Fig. 17H): curved, tapered at both ends, thickest medially, to 140 x 15 x 4 µm. Radula and jaws: 2 examined. Jaws 310 x 120 µm (Fig. 16F); radula teeth 85 µm long, serrated membrane short, about 40 µm, situated further proximally than distally; central plate asymmetrical, to 35 µm (Fig. 16G). Distribution: Continental slope and uppermost rise: Gulf of Mexico 334–1,032 m (Fig. 24C), Guiana Basin 508 m and 1,000 m (Fig. 25; Tables 1, 2, 4a). Remarks: Prochaetoderma gilrowei is distinguish from other Prochaetoderma species by its short cylindrical body with a short, broad posterium. Mid-trunk sclerites are similar to those of P. yongei Scheltema, 1985 but are ornamented, the blade with longitudinal ridges and the base and waist with longitudinal striations (Fig. 18D, F)., Published as part of Ivanov, Dmitry L. & Scheltema, Amélie H., 2008, NMR solution structures of KAP- 1 PHD finger-bromodomain, pp. 1-60 in Zootaxa 1885 on pages 26-27, DOI: 10.13018/bmr11036, http://zenodo.org/record/5133706, {"references":["Scheltema, A. H. (1985) The Aplacophoran family Prochaetodermatidae in the North American Basin, including Chevroderma n. g. and Spathoderma n. g. (Mollusca; Chaetodermomorpha). Biological Bulletin, 169, 484 - 529."]}

Claviderma amplum n. sp. (Figures 1B, 4D–F, 5, 6, 24B, 25; Tables 1, 2, 3b, 4a) Type material: Holotype USNM 1112615. Paratypes: USNM; TAMU; ZMUM Le1–167 (DGoMB, S35/1), Le1–168 (DGoMB, MT3 /3), Le1–169 (NGoMCS sample 4443, station E2a/5). Type locality: Gulf of Mexico, 28°16.77'N, 86°14.76'W, 622 m (NGoMCS, sample 4454, station E2/4, 19/05/1985). Material examined: SE Florida coast, 33 specimens (Table 3b); Gulf of Mexico, 81 specimens (Table 1); Guiana Basin, 14 specimens (Table 4a). Diagnosis: Slender, elongate, opaque, length to nearly 1 centimeter, posterium long, narrow, ¾ trunk length or greater; trunk sclerites but not shank sclerites adpressed, at 45º to longitudinal body axis; sclerites fringing knob in single row scarcely extending beyond knob. Oral shield sclerites in 5 rows, not obvious. Trunk sclerites long, to 600 µm, thick, symmetrical, proximal end narrow, waist distinct, blade short, wider than or equal to width of base, edges of blade convex, tapered to sharp distal point. Etymology: L. amplus, -a, um = large. Description: External appearance (Figs 1B, 5A–C): Body opaque, long for a prochaetodermatid, to 9.0 x 1.7 mm, shank narrow, long, posterium/trunk index 0.73–0.95, trunk width ~1/3 trunk length, holotype length 8.3 mm, anterium 0.2 mm, trunk 4.8 x 1.5 mm, shank 2.6 x 1.0 mm, knob 0.9 mm, posterium/trunk index 0.73; shank shaggy, narrower than and set off from smooth, elongate trunk; adpressed trunk sclerites diverging from ventral midline, converging along dorsal midline; fringing sclerites in single row extending to end of or beyond cone-shaped knob. Oral shield 0.12–0.15 mm in height, innermost of 5 rows of oral shield sclerites very small. Sclerites (Figs 4D–F, 5G, 6): General: curved toward body, distal tip lifted (Fig. 6J), base long, 2 to nearly 3 times blade length, tapered proximally to narrow, rounded proximal end, narrowing at waist; blade wider than base at waist, sides nearly straight to convex, tapered to distal point; thickest on base medially or just below waist. Beside oral shield (Fig. 6A): somewhat quadrate, asymmetrical, angular proximally and distally, thick, 75 x 40 x 7 µm, thickest medially. Dorsal to oral shield (Fig. 6B): very thin pointed scales, 50 x 25 x 2 µm, elongating to flame-shaped, 90 x 20 x 3 µm. Anterium (Fig. 6C): long, narrow, with distinct waist, blade equal to or wider than base, to 150 x 20 x 6 µm. Dorsal trunk (Fig. 6E, F): blade less than 1/3 total length, to 600 x 40 x 15 µm, thickened symmetrically, thickest on base near waist. Ventral trunk (Fig. 6D): similar to those from dorsal trunk, but most shorter with about same width, thickest medially on base. Shank (Fig. 6G): shorter than posterior trunk sclerites, base broadest and straight proximally, tapering to pointed distal end, waist indistinct, slightly curved, from short and broad 220 x 60 µm to longer and narrower 400 x 45 x 9 µm, thickest medially or on upper third. Fringing (Fig. 6I): long, straight, narrow, to 1,000 x 25 x> 10 µm. Radula and jaws: 2 examined. Jaws 920 x 400 µm (Fig. 5F); radula teeth 195 µm long, serrated membrane about 110 µm, situated almost medially; central plate asymmetrical, to 90 µm (Fig. 5E). Distribution (Figs 24B, 25; Tables 1, 2, 3b, 4a): A continental slope species in the Gulf of Mexico (400– 1,032 m), off the southeast coast of Florida (293–342 m), and Guiana Basin (508 and 1,000 m). The greatest number of specimens in quantitative box core samples was 104 m -2 at 667 m in the Gulf of Mexico (Table 1, S35/2). Remarks: Claviderma amplum is a large, slender species with a long, narrow "tail", the trunk and posterium of almost equal length. The sclerites of Cl. amplum are nearly indistinguishable from those of Cl. crassum, both having very long, narrow trunk sclerites with short, convex-sided blades. The two species are sympatric in the Guiana Basin, but not the Gulf of Mexico. Body morphology of the two differs particularly in trunk width and in length of posterium (short in Cl. crassum) and is often sufficient for distinguishing them. Cl. amplum does not reach the volume size of the largest specimens of Cl. crassum. See Remarks under Cl. crassum for particular differences., Published as part of Ivanov, Dmitry L. & Scheltema, Amélie H., 2008, NMR solution structures of KAP- 1 PHD finger-bromodomain, pp. 1-60 in Zootaxa 1885 on pages 11-14, DOI: 10.13018/bmr11036, http://zenodo.org/record/5133706

Spathoderma grossum Scheltema & Ivanov, 2000 Scheltema & Ivanov, 2000: 359. (Figures 25, 26; Tables 4a, 5) Additional material examined: Guiana Basin, 5 specimens (Table 4a); Argentine Basin, 66 specimens (Table 5); 1 new record, from West European Basin, 50º27.3'N, 13º20.9'W, 2,506 m (RV Chain cruise 106, stn 318, 19.08.1972). Distribution: Amphi-Atlantic: Eastern Atlantic from the West European Basin to the Cape Basin at abyssal depths> 4,000 m (Scheltema & Ivanov, 2000), except shallower in the northern West European Basin; Western Atlantic from the Guiana Basin on the continental rise at 3,859 m to the abyss at 4,980 m, and not reaching the abyss in the Argentine Basin, 2,440 –3,906 m (Figs 25, 26). Remarks: The new records indicate that S. grossum, as a primarily abyssal or lower continental rise species, occurs on both sides of the Atlantic south of 13°N, but extends further north to 50°N in the eastern Atlantic.

Chevroderma turnerae Scheltema, 1985 Scheltema 1985:512; Ivanov & Scheltema, 2002. (Figure 26; Table 5) Distribution: A primarily lower continental rise and abyssal species: North Atlantic and Newfoundland Basins, 3,264 –5,018 m; Argentine Basin, 2,707 –5,208; mid-Atlantic at the Equator, 3,459 –3,730 m; eastern Atlantic from the West European Basin to the Cape Basin, 2,124 –4,829 m; western Indian Ocean, 3,272 – 3,888 m; and eastern Indian Ocean (Bay of Bengal), 2,520 m (Scheltema 1985, Ivanov & Scheltema 2002). Remarks: With its great geographic range from the western Atlantic to the Indian Ocean, and great depth distribution, Chevroderma turnerae may form a species complex. The apparent lack of continuity in the western Atlantic between the North American and Argentine Basins is discussed below., Published as part of Ivanov, Dmitry L. & Scheltema, Amélie H., 2008, NMR solution structures of KAP- 1 PHD finger-bromodomain, pp. 1-60 in Zootaxa 1885 on page 11, DOI: 10.13018/bmr11036, http://zenodo.org/record/5133706, {"references":["Scheltema, A. H. (1985) The Aplacophoran family Prochaetodermatidae in the North American Basin, including Chevroderma n. g. and Spathoderma n. g. (Mollusca; Chaetodermomorpha). Biological Bulletin, 169, 484 - 529.","Ivanov, D. L. & Scheltema, A. H. (2002) Prochaetodermatidae of the Indian Ocean collected during Soviet VITYAZ cruises 1959 - 1964 (Mollusca: Aplacophora). Molluscan Research, 22, 183 - 202."]}

Chevroderma cuspidatum n. sp. (Figures 1A, 2, 3, 4A–C, 24A; Table 1) Type material: Holotype USNM 1112616. Paratypes: USNM; TAML; ZMUM Le1-166 (type locality); Le1- 164 (DGoMB, MT2 /2); Le1-165 (DGoMB, MT3 /3). Type locality: Gulf of Mexico, 28°13.22'N, 89°29.77'W, 983 m (DGoMB, MT3 /1, 16.06.2000). Material examined: Gulf of Mexico, 564 specimens (Table 1). Diagnosis: Small (Etymology: L. cuspidatus -a, -um = pointed. Description: External appearance (Figs. 1A, 2A, B): Nearly transparent, smooth body Sclerites (Figs 2F, G, 3, 4A–C): General: anterium through shank with slightly raised, distal, pointed blade, or nipple; base curved toward body (Fig. 3J); from ventral anterium, dorsal trunk, and ventral trunk, sausageshaped, of even width; juveniles as in adults but smaller (Fig. 2G). Beside oral shield (Fig. 3A): asymmetrical, curved, rounded basally and distally, groove indistinct, thin, to 36 x 16 x 2 µm, thickest medially. Dorsal to oral shield (Fig. 3B): grooved thin scales tapered to blunt point, to 30 x 14 x 1 µm. Dorsal and lateral anterium (Fig. 3C): of even width or basally broad, most with distinct, medially offset groove, proximal end angular, to 90 x 18 x 4–5 µm, gradually becoming narrower and thicker ventrally (Fig. 3D), similar to ventral trunk sclerites. Ventral trunk (Fig. 3E): shorter than dorsal trunk, to 80 x 15 µm. Dorsal trunk (Fig. 3F): as in diagnosis, to 120 x 20 x 5 µm, thickest medially beside distinct or indistinct groove. Shank (Fig. 3G): from small sausage-shaped to long and tapered from angular proximal end to distal end, thickest medially, to 140 x 30 x 7 µm. Fringing (Fig. 3I): long, straight, narrow, some with distinct waist, to 190 x 10 µm, most to 4 µm thick but up to 7 µm. Knob (Fig. 3H): short, extremely narrow to somewhat proximally broadened needles, to 90 x 7 x 2 µm. Radula and jaws: 2 examined. Jaws 210 x 75 µm (Fig. 2D); radula teeth 53 µm long, serrated membrane about 30 µm, situated almost in middle of tooth; central plate symmetrical, to 25 µm (Fig. 2E). Distribution: Known only from the continental slope of the Gulf of Mexico between 357 and 1,032 m (Fig. 24A; Table 1). Remarks: Chevroderma cuspidatum inhabits shallower depths than other known Chevroderma species. It is the only Chevroderma species in the Gulf of Mexico. C. cuspidatum may be endemic to the Gulf of Mexico. The closely adpressed, sausage-shaped sclerites with a sharp, distal nipple diverge morphologically from all other Chevroderma sclerites, although a similar morphology occurs in two undescribed Pacific species. In outline they are similar to those of Prochaetoderma? atlanticum Scheltema & Ivanov, but having a groove and chevron-shaped growth lines, as well as the angled base of Chevroderma species on anterium and shank sclerites. We interpret the slightly raised, sharp nipple as all that remains of a blade on these otherwise closely adpressed sclerites (Figs 3J, 4A – C)., Published as part of Ivanov, Dmitry L. & Scheltema, Amélie H., 2008, NMR solution structures of KAP- 1 PHD finger-bromodomain, pp. 1-60 in Zootaxa 1885 on pages 6-9, DOI: 10.13018/bmr11036, http://zenodo.org/record/5133706

Prochaetodermatidae Salvini-Plawen, 1972 Salvini-Plawen, 1969, without diagnosis. Diagnosis: Usually, Published as part of Ivanov, Dmitry L. & Scheltema, Amélie H., 2008, NMR solution structures of KAP- 1 PHD finger-bromodomain, pp. 1-60 in Zootaxa 1885 on page 5, DOI: 10.13018/bmr11036, http://zenodo.org/record/5133706

Spathoderma grossum Scheltema & Ivanov, 2000 Scheltema & Ivanov, 2000: 359. (Figures 25, 26; Tables 4a, 5) Additional material examined: Guiana Basin, 5 specimens (Table 4a); Argentine Basin, 66 specimens (Table 5); 1 new record, from West European Basin, 50º27.3'N, 13º20.9'W, 2,506 m (RV Chain cruise 106, stn 318, 19.08.1972). Distribution: Amphi-Atlantic: Eastern Atlantic from the West European Basin to the Cape Basin at abyssal depths> 4,000 m (Scheltema & Ivanov, 2000), except shallower in the northern West European Basin; Western Atlantic from the Guiana Basin on the continental rise at 3,859 m to the abyss at 4,980 m, and not reaching the abyss in the Argentine Basin, 2,440 –3,906 m (Figs 25, 26). Remarks: The new records indicate that S. grossum, as a primarily abyssal or lower continental rise species, occurs on both sides of the Atlantic south of 13°N, but extends further north to 50°N in the eastern Atlantic., Published as part of Ivanov, Dmitry L. & Scheltema, Amélie H., 2008, NMR solution structures of KAP- 1 PHD finger-bromodomain, pp. 1-60 in Zootaxa 1885 on page 33, DOI: 10.13018/bmr11036, http://zenodo.org/record/5133706, {"references":["Scheltema, A. H. & Ivanov, D. L. (2000) Prochaetodermatidae of the Eastern Atlantic Ocean and Mediterranean Sea (Mollusca, Aplacophora). Journal of Molluscan Studies, 66, 313 - 362."]}

Claviderma compactum n. sp. (Figures 1C, 7, 8, 13A, B; Table 5) Type material: Holotype USNM 1112622. Paratypes: USNM; TAMU; ZMUM Le1–172 (type locality); Le1–173 (AII-60 239); Le1–174 (AII-60 239); Le1–175 (AII-60 240); Le1–176 (AII-60 262). Type locality: Argentine Basin, 36°12.7'S, 52°42.7'W, 2,041 m (RV Atlantis II Cruise 60, station 264, 28.03.1971). Material examined: Argentine Basin, 687 specimens (Table 5). Diagnosis: A small Claviderma species Etymology: L. compactus, -a, -um = compact. Description: External appearance (Figs 1C, 7A–C): General: Small, trunk smooth, sclerites raised on shank giving it fuzzy, wide appearance; holotype length 2.7 mm, anterium 0.1 mm, trunk 1.6 x 0.6 mm, shank 0.6 X 0.4 mm, knob 0.4 mm, posterium/trunk index 0.37; base of large jaws within hemocoele forming an anteroventral bulge raising sclerites upright (Fig. 7A–C, arrows); trunk sclerites arranged from anteroventral to dorsoposterior, diverging from ventral midline rather far posteriorly but not converging dorsally. Oral shield 0.18 mm in height. Sclerites (Figs 7D, G, 8): General: Blade very short above waist on anterodorsal trunk, lengthening gradually posteriorly to the shank, thickest medially on base of trunk sclerites, thick for size of sclerites. Oral shield (Fig. 7D, 8A): triangular with rounded, angular base, rounded distally, thickest proximally, 65 x 30 x> 3 µm; of nearly equal size in the 3 rows, largest dorsally. Dorsal to oral shield (Fig. 8B): oval or with waist, 50 x 25 x 2 µm. Anterium (Fig. 8C): asymmetrical and deeply waisted, to 100 x 25 x 3 µm. Trunk beneath anteroventral bulge (Fig. 8D): 2 types, one with deep waist like anterium sclerites, the other ovoid with a short blade, to 110 x 30 x 5 µm, thickest medially on base. Ventral trunk posterior to bulge (Fig. 8E, F): like second type of sclerites beneath bulge, but larger and with longer blades,>200 x 40 x 7 µm, thickest medially or distally on base. Dorsal trunk sclerites from anterior to posterior (Fig. 8G, H): similar to ventral sclerites, width of base nearly the same throughout trunk, base and blade both increasing in length, with blade increasing from 1/7 to 1/4 total length, from 150 x 30 x 4 µm to 250 x 35 x 8 µm, thickest medially on base. Shank (Fig. 8I): 2 types, one type with shape like trunk sclerites but with longer blade up to 1/2 total length, to 280 x 30 x 8 µm, thickest on blade; the second type shorter with a wide quadrate base, base and blade of about equal length, to 220 x 60 x 7 µm, thickest medially on blade. Fringe (Fig. 8J): with quadrate base and blade about 3 times length of base, 360 x 50 x 10 µm, or needle-like, 340 x15 x 8 µm. Knob (Fig. 8K): short, straight, tapered or swollen proximally, to 210 x 20 x 4 µm, or very long and hair-like, to 500 x Radula and jaws: 2 examined. Jaws 520 x 200 µm (Fig. 7E); radula teeth 140 µm long, serrated membrane about 90 µm long, medial; central plate symmetrical, curved, 30 x 10 µm (Fig. 7F). Distribution (Fig. 25, Table 5): Known from 5 stations in the Argentine Basin at just above to within the continental rise (993–3,343 m) (Table 5). Remarks: Cl. compactum is distinguished from other Claviderma species by: a wide and fuzzy short shank and small size; 3 rows of oral shield sclerites almost equal in size; short, and narrow sclerite blades with straight sides tapering to a narrow proximal end. The anatomy of the relationship between jaws and hemocoele is found in Scheltema (1981)., Published as part of Ivanov, Dmitry L. & Scheltema, Amélie H., 2008, NMR solution structures of KAP- 1 PHD finger-bromodomain, pp. 1-60 in Zootaxa 1885 on pages 14-15, DOI: 10.13018/bmr11036, http://zenodo.org/record/5133706, {"references":["Scheltema, A. H. (1981) Comparative morphology of the radulae and alimentary tracts in the Aplacophora. Malacologia, 20, 361 - 383."]}

Claviderma amplum n. sp. (Figures 1B, 4D–F, 5, 6, 24B, 25; Tables 1, 2, 3b, 4a) Type material: Holotype USNM 1112615. Paratypes: USNM; TAMU; ZMUM Le1–167 (DGoMB, S35/1), Le1–168 (DGoMB, MT3 /3), Le1–169 (NGoMCS sample 4443, station E2a/5). Type locality: Gulf of Mexico, 28°16.77'N, 86°14.76'W, 622 m (NGoMCS, sample 4454, station E2/4, 19/05/1985). Material examined: SE Florida coast, 33 specimens (Table 3b); Gulf of Mexico, 81 specimens (Table 1); Guiana Basin, 14 specimens (Table 4a). Diagnosis: Slender, elongate, opaque, length to nearly 1 centimeter, posterium long, narrow, ¾ trunk length or greater; trunk sclerites but not shank sclerites adpressed, at 45º to longitudinal body axis; sclerites fringing knob in single row scarcely extending beyond knob. Oral shield sclerites in 5 rows, not obvious. Trunk sclerites long, to 600 µm, thick, symmetrical, proximal end narrow, waist distinct, blade short, wider than or equal to width of base, edges of blade convex, tapered to sharp distal point. Etymology: L. amplus, -a, um = large. Description: External appearance (Figs 1B, 5A–C): Body opaque, long for a prochaetodermatid, to 9.0 x 1.7 mm, shank narrow, long, posterium/trunk index 0.73–0.95, trunk width ~1/3 trunk length, holotype length 8.3 mm, anterium 0.2 mm, trunk 4.8 x 1.5 mm, shank 2.6 x 1.0 mm, knob 0.9 mm, posterium/trunk index 0.73; shank shaggy, narrower than and set off from smooth, elongate trunk; adpressed trunk sclerites diverging from ventral midline, converging along dorsal midline; fringing sclerites in single row extending to end of or beyond cone-shaped knob. Oral shield 0.12–0.15 mm in height, innermost of 5 rows of oral shield sclerites very small. Sclerites (Figs 4D–F, 5G, 6): General: curved toward body, distal tip lifted (Fig. 6J), base long, 2 to nearly 3 times blade length, tapered proximally to narrow, rounded proximal end, narrowing at waist; blade wider than base at waist, sides nearly straight to convex, tapered to distal point; thickest on base medially or just below waist. Beside oral shield (Fig. 6A): somewhat quadrate, asymmetrical, angular proximally and distally, thick, 75 x 40 x 7 µm, thickest medially. Dorsal to oral shield (Fig. 6B): very thin pointed scales, 50 x 25 x 2 µm, elongating to flame-shaped, 90 x 20 x 3 µm. Anterium (Fig. 6C): long, narrow, with distinct waist, blade equal to or wider than base, to 150 x 20 x 6 µm. Dorsal trunk (Fig. 6E, F): blade less than 1/3 total length, to 600 x 40 x 15 µm, thickened symmetrically, thickest on base near waist. Ventral trunk (Fig. 6D): similar to those from dorsal trunk, but most shorter with about same width, thickest medially on base. Shank (Fig. 6G): shorter than posterior trunk sclerites, base broadest and straight proximally, tapering to pointed distal end, waist indistinct, slightly curved, from short and broad 220 x 60 µm to longer and narrower 400 x 45 x 9 µm, thickest medially or on upper third. Fringing (Fig. 6I): long, straight, narrow, to 1,000 x 25 x> 10 µm. Radula and jaws: 2 examined. Jaws 920 x 400 µm (Fig. 5F); radula teeth 195 µm long, serrated membrane about 110 µm, situated almost medially; central plate asymmetrical, to 90 µm (Fig. 5E). Distribution (Figs 24B, 25; Tables 1, 2, 3b, 4a): A continental slope species in the Gulf of Mexico (400– 1,032 m), off the southeast coast of Florida (293–342 m), and Guiana Basin (508 and 1,000 m). The greatest number of specimens in quantitative box core samples was 104 m -2 at 667 m in the Gulf of Mexico (Table 1, S35/2). Remarks: Claviderma amplum is a large, slender species with a long, narrow "tail", the trunk and posterium of almost equal length. The sclerites of Cl. amplum are nearly indistinguishable from those of Cl. crassum, both having very long, narrow trunk sclerites with short, convex-sided blades. The two species are sympatric in the Guiana Basin, but not the Gulf of Mexico. Body morphology of the two differs particularly in trunk width and in length of posterium (short in Cl. crassum) and is often sufficient for distinguishing them. Cl. amplum does not reach the volume size of the largest specimens of Cl. crassum. See Remarks under Cl. crassum for particular differences.

We study in the BFKL approach the total hadronic cross section for the collision of two virtual photons for energies in the range of LEP2 and in the range of future linear colliders. The BFKL resummation is done at the next-to-leading order in the BFKL Green's function; photon impact factors are taken instead at the leading order, but with the inclusion of the subleading terms required by invariance under changes of the renormalization scale and of the BFKL scale s_0. We compare our results with previous estimates based on a similar kind of approximation., Comment: 12 pages, 5 figures, uses axodraw.sty

The forward electroproduction of two light vector mesons is the first example of a collision process between strongly interacting colorless particles for which the amplitude can be written completely within perturbative QCD in the Regge limit with next-to-leading accuracy. This amplitude can be written as a convolution of two impact factors for the virtual photon to light vector meson transition with the BFKL Green's function. In this lecture we first describe how the relevant impact factor is calculated, then we perform the convolution with the BFKL Green's function and illustrate the numerical procedure to obtain a well-behaved amplitude., Comment: Presented at the ``School on QCD, Low-x Physics, Saturation and Diffraction'', Copanello (Calabria, Italy), July 1 - 14, 2007; 27 pages, 9 figures

A study of cross sections and azimuthal correlation moments for the inclusive production of two, light charged hadrons featuring large transverse momenta and well separated in rapidity at LHC energies, including BFKL resummation effects with NLA accuracy, is presented. This reaction shares the same theoretical setup with the well konwn Mueller-Navelet jet production and can be thought of as a new and complementary channel to access the BFKL dynamics at proton colliders., 6 pages, 1 figure, presented by F.G. Celiberto at the 17th conference on Elastic and Diffractive Scattering, EDS Blois 2017, Prague, Czech Republic, June 26-30, 2017

Working in the hybrid high-energy/collinear factorization, where the next-to-leading resummation of energy logarithms is combined with collinear parton densities and fragmentation functions, we study observables sensitive to high-energy dynamics in the context of heavy-flavor physics., Comment: 6 pages, 1 figure. Presented by Michael Fucilla at "Diffraction and Low-$x$ 2022", Corigliano Calabro (Italy), September 24-30, 2022

Heavy-flavored emissions have been always considered as an excellent channel to test properties of Quantum chromodynamics (QCD) at present and future colliders. Among different regimes, in which heavy-flavor production can be investigated, we focus our attention on the semi-hard one, where $s \gg \{ Q^2 \} \gg \Lambda_{QCD}$ ($s$ is the squared center-of-mass energy, $\{ Q^2 \}$ a (set of) hard scale(s) characteristic of the process and $\Lambda_{QCD}$ the QCD mass scale). Here, we build predictions in a hybrid collinear/high-energy factorization, in which the standard collinear description is supplemented by the Balitsky-Fadin-Kuraev-Lipatov resummation of large energy logarithms. The definition and the study of observables sensitive to high-energy dynamics in the context of heavy-flavor physics has the double advantage of (i) allowing to get a stabilization of the BFKL series under higher-order corrections and (ii) providing us with an auxiliary tool to investigate heavy-flavor production in wider kinematical ranges. Hence, we propose a scientific program on heavy-flavor physics at high-energy with the goal of considering both open (heavy-jet) and bound states ($\Lambda$ baryons, heavy-light mesons and quarkonia)., Comment: 6 pages, 2 figures; Presented by M, Fucilla at the European Physical Society Conference on High Energy Physics (EPS-HEP2021), 26-30 July 2021; to be published in the conference proceedings by PoS

The gluon content of the proton is embodied by the unintegrated gluon distribution (UGD), which has universal validity. In literature many models of UGD have been proposed so far. The polarized $\rho$-meson leptoproduction at HERA offers a nowadays unexplored testfield to discriminate among existing models of UGD, via the comparison with theoretical predictions formulated in the $\kappa$-factorization approach., Comment: 6 pages, 3 figures, Talk given at the XIX Frascati Spring School "Bruno Touschek" in nuclear, subnuclear and astroparticle physics, Frascati, 7-11 May 2018