bluuebunny/crossref_metadata_2025_split huggingface dataset:
Phenomenological and existential contributions to the study of erectile dysfunction
Authors: Suijker Chris A. , van Mazijk Corijn , Keijzer Fred A. , Meijer Boaz 
Published: June 2021

AbstractThe current medical approach to erectile dysfunction (ED) consists of physiological, psychological and social components. This paper proposes an additional framework for thinking about ED based on phenomenology, by focusing on the theory of sexual projection. This framework will be complementary to the current medical approach to ED. Our phenomenological analysis of ED provides philosophical depth and illuminates overlooked aspects in the study of ED. Mainly by appealing to Merleau-Ponty’s Phenomenology of Perception, we suggest considering an additional etiology of ED in terms of a weakening of a function of sexual projection. We argue that sexual projection can be problematized through cognitive interferences, changes in the ‘intentional arc’, and modifications in the subject’s ‘body schema’. Our approach further highlights the importance of considering the ‘existential situation’ of patients with ED. We close by reflecting briefly on some of the implications of this phenomenological framework for diagnosis and treatment of ED.
Optimal solutions of multiplier DEA models
Authors: Podinovski Victor V. , Bouzdine-Chameeva Tatiana 
Published: June 2021

AbstractConventional models of data envelopment analysis (DEA) are based on the constant and variable returns-to-scale production technologies. Any optimal input and output weights of the multiplier DEA models based on these technologies are interpreted as being the most favorable for the decision making unit (DMU) under the assessment when the latter is benchmarked against the set of all observed DMUs. In this paper we consider a very large class of DEA models based on arbitrary polyhedral technologies, which includes almost all known convex DEA models. We highlight the fact that the conventional interpretation of the optimal input and output weights in such models is generally incorrect, which raises a question about the meaning of multiplier models. We address this question and prove that the optimal solutions of such models show the DMU under the assessment in the best light in comparison to the entire technology, but not necessarily in comparison to the set of observed DMUs. This result allows a clear and meaningful interpretation of the optimal solutions of multiplier models, including known models with a complex constraint structure whose interpretation has been problematic and left unaddressed in the existing literature.
On completely factoring any integer efficiently in a single run of an order-finding algorithm
Authors: Ekerå Martin 
Published: June 2021

AbstractWe show that given the order of a single element selected uniformly at random from $${\mathbb {Z}}_N^*$$

Z
N
∗

, we can with very high probability, and for any integer N, efficiently find the complete factorization of N in polynomial time. This implies that a single run of the quantum part of Shor’s factoring algorithm is usually sufficient. All prime factors of N can then be recovered with negligible computational cost in a classical post-processing step. The classical algorithm required for this step is essentially due to Miller.
Innovations and new possibilities of vehicle tracking in transport and forwarding
Authors: Huk Katarzyna , Kurowski Mateusz 
Published: June 2021

AbstractChanges taking place on the market set new development trends and create new threats which enterprises must face. If management does not take up the challenge, the company's development may slow down and fail to cope with the growing competition. That is why it is so important to flexibly adapt to changing economic conditions and implement innovations. New solutions and improvements can be observed in every area of the company's activity, in particular industries and sectors of the economy. Keeping up with new trends and implementing innovations is now a determinant of achieving a competitive advantage. New solutions and opportunities also apply to the TSL industry (transport, forwarding, logistics). New innovations and opportunities arise constantly in different areas of this field. The subject of interest of this article is the development and innovation in the field of road transport and IT systems implemented in enterprises. The study was prepared on the basis of the literature review and own study based on transport, forwarding and the group representing other sectors of economy. The aim of the study is to identification innovations and new possibilities in the field of telematics systems used to identify transportation units in motion.
k-Provability in $$\hbox {PA}$$
Authors: Santos Paulo Guilherme , Kahle Reinhard 
Published: June 2021

AbstractWe study the decidability ofk-provability in$$\hbox {PA}$$PA—the relation ‘being provable in$$\hbox {PA}$$PAwith at mostksteps’—and the decidability of the proof-skeleton problem—the problem of deciding if a given formula has a proof that has a given skeleton (the list of axioms and rules that were used). The decidability ofk-provability for the usual Hilbert-style formalisation of$$\hbox {PA}$$PAis still an open problem, but it is known that the proof-skeleton problem is undecidable for that theory. Using new methods, we present a characterisation of some numberskfor whichk-provability is decidable, and we present a characterisation of some proof-skeletons for which one can decide whether a formula has a proof whose skeleton is the considered one. These characterisations are natural and parameterised by unification algorithms.
Effectiveness and petroleum geological significance of tectonic fractures in the ultra-deep zone of the Kuqa foreland thrust belt: a case study of the Cretaceous Bashijiqike Formation in the Keshen gas field
Authors: Zhang Rong-Hu , Wang Ke , Zeng Qing-Lu , Yu Chao-Feng , Wang Jun-Peng 
Published: June 2021

AbstractThe buried depth of the gas-producing reservoir in the Kuqa foreland thrust belt of the Tarim Basin exceeds 6000 m. The average matrix porosity of the reservoir is 5.5%, and the average matrix permeability is 0.128 × 10−3 μm2. In order to reveal the characteristics and effectiveness of ultra-deep fractures and their effects on reservoir properties and natural gas production, outcrops, cores, thin section, image logs and production testing data are used to investigate the effectiveness of tectonic fractures in ultra-deep reservoirs in the Kuqa foreland thrust zone, and the corresponding geological significance for oil and gas exploration and development are discussed. Tectonic fractures in the thrust belt include EW-trending high-angle tensile fractures and NS-trending vertical shear fractures. The former has a relatively high filling rate, while the latter is mostly unfilled. Micro-fractures are usually grain-piercing-through cracks with width of 10–100 microns. In the planar view, the effective fractures are concentrated in the high part and wing zones of the long axis of the anticline, and along the vertical direction, they are mainly found in the tensile fracture zone above the neutral plane. The adjustment fracture zone has the strongest vertical extension abilities and high effectiveness, followed by the nearly EW longitudinal tensile fracture zone, and the netted fracture zone with multiple dip angles. The effectiveness of fracture is mainly controlled by fracture aperture and filling degrees. Effective fractures can increase reservoir permeability by 1–2 orders of magnitude. The higher part of the anticline is associated with high tectonic fracture permeability, which control enrichment and high production of natural gas. The netted vertical open fractures effectively communicate with pores and throats of the reservoir matrix, which forms an apparent-homogenous to medium-heterogeneous body that is seen with high production of natural gas sustained for a long term.
Heritage Outreach, Fossils, Dinosaurs and Sites: How Locals’ Perception Changes After 10 Years of Actions in Historic Urban Villages (Cuenca, Spain)
Authors: de la Cita Lara , Llandres Mercedes , Buscalioni Ángela D. 
Published: June 2021

AbstractCuenca, a small city with a rich historical and palaeontological heritage, is the ideal location to explore how the scientific knowledge of its inhabitants has changed over the years. In 2010 and 2019, two surveys were conducted on the streets of Cuenca to characterise their scientific profiles and how they perceive heritage outreach initiatives in palaeontology (i.e. visits and non-formal education in museums, research dissemination and mass media). For the present study, 320 responses were analysed through multivariate techniques (multiple correspondence analysis or MCA), using simple binary states and multiple nominal states. The results showed a significant disparity in the age demographic category: on the one hand, young people (< 18 years old) retained more scientific information linked to educational activities than older people in 2010; on the other hand, older Cuenca natives (> 55 and 35–55 years old) were the most informed and influenced by outreach and media in 2019, some of them even forming a particular group of palaeontology and dinosaur enthusiasts, herein named ‘paleo-geeks’. In general, it was found that the majority of answers were congruent within the same year and corresponded with the sociocultural changes that Cuenca had experienced, from a rural to a more urban and diverse culture. Lastly, it was concluded that heritage outreach initiatives do influence the scientific profiles of Cuenca’s inhabitants.
Geometrisches Begriffsverständnis in der Grundschule am Beispiel der Begriffe Viereck, Rechteck und Quadrat
Authors: Bruns Julia , Unterhauser Elisabeth , Gasteiger Hedwig 
Published: June 2021

ZusammenfassungZu den ersten geometrischen Begriffen, die Kinder bereits im Elementar- und Primarbereich lernen, zählen u. a. Viereck, Rechteck und Quadrat. Studien zeigen, dass Lernende bereits früh individuelle Vorstellungen, sog. individuelle Begriffskonzepte, zu diesen Begriffen aufbauen. Zwar wird die Entwicklung von Begriffsverständnis in verschiedenen mathematikdidaktischen Stufenmodellen dargestellt, diese sind jedoch generisch und beschreiben nicht explizit die Entwicklung der ersten individuellen Begriffskonzepte von Lernenden zu Viereck, Rechteck und Quadrat. Aus empirischer Sicht liegen verschiedene Studien vor, die einzelne Aspekte der individuellen Begriffskonzepte von Lernenden unterschiedlicher Altersgruppen zu diesen Begriffen ausleuchten. Um Begriffsbildungsprozesse aus empirischer Sicht detaillierter entlang der jeweils vorherrschenden individuellen Begriffskonzepte zu beschreiben, fehlen insbesondere Studien in der Grundschule, die alle vier Klassenstufen betrachten und dabei differenzierte Erkenntnisse zu verschiedenen theoretischen Indikatoren des Begriffsverständnisses liefern. Daher geht die vorliegende Studie der Frage nach, welches Verständnis der Begriffe Viereck, Rechteck und Quadrat Schülerinnen und Schüler der Jahrgangsstufen 1, 2, 3 und 4 zeigen. Dazu wurde eine Quasi-Längsschnittstudie mit N = 456 Grundschulkindern (ca. 100 pro Jahrgangsstufe) durchgeführt. Die Ergebnisse geben detaillierte Einblicke in die individuellen Begriffskonzepte der Lernenden und zeigen, dass Lernende zunehmend Eigenschaften der Figuren berücksichtigen, jedoch individuelle Begriffskonzepte über lange Zeit auch prototypisch geprägt sind. Implikationen dieser Ergebnisse für Forschung und Praxis werden diskutiert.
How unnecessarily high abatement costs and unresolved distributional issues undermine nutrient reductions to the Baltic Sea
Authors: Andersson Anna , Brady Mark V. , Pohjola Johanna 
Published: June 2021

AbstractThis paper systematically reviews the literature on how to reduce nutrient emissions to the Baltic Sea cost-effectively and considerations for allocating these costs fairly among countries. The literature shows conclusively that the reduction targets of the Baltic Sea Action Plan (BSAP) could be achieved at considerably lower cost, if countries would cooperate to implement the least costly abatement plan. Focusing on phosphorus abatement could be prudent as the often recommended measures—wastewater treatment and wetlands—abate nitrogen too. An implication of our review is that the potential for restoring the Baltic Sea to good health is undermined by an abatement strategy that is more costly than necessary and likely to be perceived as unfair by several countries. Neither the BSAP nor the cost-effective solution meet the surveyed criteria for fairness, implying a need for side-payments.
Investigation of the heat distribution in dry friction systems during fade and recovery using fiber-optic sensing and infrared technology
Authors: Albers Albert , Klotz Thomas , Fink Chris , Ott Sascha 
Published: June 2021

AbstractThe design of dry-running friction pairings and systems determines not only their installation space and costs, but also their reliability under critical load conditions, for example in emergencies, in the case of faults, and in the event of misuse. While knowledge of the contact pattern is highly important for the development of clutches and brakes, the contact-related measurement of the temperature of these systems has not yet been solved in a satisfactory manner. Despite its importance, the temperature distribution has only been measured in a few studies. Typically, temperature measurements of complete clutches and brakes are carried out using thermocouples only. In this study, a new innovative test setup is presented. This setup is able to measure the heat distribution of the lining and the steel disk of a brake with high spatial resolution by means of fiber optic sensing technology and thermography. As a novelty, it enables measurement of the heat distribution and allows to correlate it with the fade and recovery behavior. Contrary to the expectations, the contact pattern is heterogeneous in circumferential direction. Possible causes are discussed using simulation results. Along with surface analysis, the new setup contributes to the investigation of the causes of fade and recovery.
Consistent Alterations of Human Fecal Microbes After Transplantation into Germ-Free Mice
Authors: Li Yanze , Cao Wenming , Gao Na L , Zhao Xing-Ming , Chen Wei-Hua 
Published: June 2021

Abstract
Fecal microbiota transplantation (FMT) of human fecal samples into germ-free (GF) mice is useful for establishing causal relationships between the gut microbiota and human phenotypes. However, due to the intrinsic differences between human and mouse intestines and the different diets of the two organisms, it may not be possible to replicate human phenotypes in mice through FMT; similarly, treatments that are effective in mouse models may not be effective in humans. In this study, we aimed to identify human gut microbes that undergo significant and consistent changes (i.e., in relative abundances) after transplantation into GF mice in multiple experimental settings. We collected 16S rDNA-seq data from four published studies and analyzed the gut microbiota profiles from 1713 human–mouse pairs. Strikingly, on average, we found that only 47% of the human gut microbes could be re-established in mice at the species level, among which more than 1/3 underwent significant changes (referred to as “variable taxa”). Most of the human gut microbes that underwent significant changes were consistent across multiple human–mouse pairs and experimental settings. Consequently, about 1/3 of human samples changed their enterotypes, i.e., significant changes in their leading species after FMT. Mice fed with a controlled diet showed a lower enterotype change rate (23.5%) than those fed with a noncontrolled diet (49.0%), suggesting a possible solution for rescue. Most of the variable taxa have been reported to be implicated in human diseases, with some recognized as the causative species. Our results highlight the challenges of using a mouse model to replicate human gut microbiota-associated phenotypes, provide useful information for researchers using mice in gut microbiota studies, and call for additional validations after FMT. An online database named FMT-DB is publicly available at http://fmt2mice.humangut.info/#/.
Iron status of full-term infants in early infancy is not associated with maternal ferritin levels nor infant feeding practice
Authors: Chan Kate C. , Tsun Joseph G. S. , Li Albert M. , Tam Wing Hung 
Published: June 2021

AbstractIron deficiency (ID) in early life is associated with morbidities. Most fetal iron required for infant growth is acquired in the third trimester from maternal iron store. However, how prenatal iron level affects ferritin level in early infancy remains controversial. This study aimed to examine the associations between maternal ferritin levels and cord blood serum ferritin (CBSF) and to compare the ferritin levels between different feeding practices in early infancy. Healthy Chinese mothers with uncomplicated pregnancy and their infants were followed up at 3 months post-delivery for questionnaire completion and infant blood collection. Infants who were predominantly breastfed and those who were predominantly formula fed were included in this analysis. Serum ferritin levels were measured in maternal blood samples collected upon delivery, cord blood and infant blood samples at 3 months of age. Ninety-seven mother–baby dyads were included. Maternal ID is common (56 %) while the CBSF levels were significantly higher than maternal ferritin levels. Only three infants (3 %) had ID at 3 months of age. There were no significant correlations between maternal ferritin levels with CBSF (r 0·168, P = 0·108) nor with infant ferritin levels at 3 months of age (r 0·023, P = 0·828). Infant ferritin levels at 3 months were significantly and independently associated with CBSF (P = 0·007) and birth weight (P < 0·001) after adjusting for maternal age, parity, maternal education, infant sex and feeding practice. In conclusion, maternal ID was common upon delivery. However, maternal ferritin levels were not significantly associated with CBSF concentrations nor infant ferritin concentrations at 3 months of age.
Crude Calculations: Productivity and the Profitability of Conquest
Authors: Coe Andrew J. , Markowitz Jonathan N. 
Published: June 2021

AbstractFor many centuries, conquest was commonplace, and its attractiveness was central to the character of international politics. Why has it declined? Existing theories cannot explain why powerful countries no longer conquer states with easily extractable wealth. We develop an explanation based on the relationship between a potential conqueror's economic productivity and its ability to profit from conquest. Productivity has opposing effects on conquest's profitability: it raises the opportunity cost of each asset diverted to conquest, but also reduces the quantity of assets required for conquest. The net effect is determined by the composition of investment in innovation. We document that since at least 1950 investment has been predominantly aimed at civilian, not military innovations, so that rising productivity should reduce conquest's net profitability. Using cost analyses of comparable wars, we estimate bounds on the profitability of conquering the oil and gas reserves of the Persian Gulf, a very tempting target, for the United States and Iraq, two potential conquerors of widely differing productivity. Though both mechanisms operate, we find that the net effect of higher productivity is to reduce the profits from conquest. Moreover, this net effect is large enough to render conquest generally unprofitable for contemporary high-productivity states.
Communication-free autonomous cooperative circumnavigation of unpredictable dynamic objects
Authors: Matveev A. S. , Magerkin V. V. 
Published: June 2021

AbstractEach of several speed-limited planar robots is driven by the acceleration, limited in magnitude. There is an unpredictable dynamic complex object, for example, a group of moving targets or an extended moving and deforming body. The robots should reach and then repeatedly trace a certain object-dependent moving and deforming curve that encircles the object and also achieve an effective self-deployment over it. This may be, for example, the locus of points at a desired mean distance or distance from a group of targets or a single extended object, respectively. Every robot has access to the nearest point of the curve and its own velocity and “sees” the objects within a finite sensing range. The robots have no communication facilities, cannot differentiate the peers, and are to be driven by a common law. Necessary conditions for the solvability of the mission are established. Under their slight and partly unavoidable enhancement, a new decentralized control strategy is proposed and shown to solve the mission, while excluding inter-robot collisions, and for the case of a steady curve, to evenly distribute the robots over the curve and to ensure a prespecified speed of their motion over it. These are justified via rigorous global convergence results and confirmed via computer simulations.
An Analytical Model for Lateral Erosion From Saltating Bedload Particle Impacts
Authors: Li Tingan , Venditti Jeremy G. , Sklar Leonard S. 
Published: June 2021

AbstractThe width of bedrock rivers is set by the competition between vertical and lateral erosion in uplifting landscapes. Compared with vertical erosion rates, less is known about the lateral erosion rates that are thought to dominate when river beds are alluviated. Here, we derive an analytical model for lateral erosion by saltating bedload particle impacts that are deflected by alluvial cover. The analytical model is a simplification of the Li et al. (2020, https://doi.org/10.1029/2019jf005509) numerical model of the same process. The analytical model predicts a nonlinear dependence of lateral erosion rate on sediment supply, shear stress, and grain size, revealing the same behavior observed in the numerical model, but without tracking particle movements through time and space. The analytical model considers both uniformly distributed cover and patchy partial cover that are implemented with a fully alluviated patch along one bank and bare bedrock along the other. The model predicts that lateral erosion rate peaks when the bed is ∼70% covered for uniformly distributed alluvium, or when the bed is fully covered for patchy alluvium. Vertical erosion dominates over lateral erosion for ∼75% and >90% of sediment supply and transport stage conditions for uniformly distributed cover and patchy cover, respectively. We use the model to derive a phase diagram of channel responses (steepening, flattening, narrowing, and widening) for various combinations of transport stage and relative sediment supply. Application of our model to Boulder Creek, CA, captures the observed channel widening in response to increased sediment supply and steepening in response to larger grain size.