scholarly journals Publisher Correction to: Swiss Journal of Palaeontology, vol 139

2021 ◽  
Vol 140 (1) ◽  
Author(s):  
Keyword(s):  
Technical Problem ◽  
Swiss Journal

Two [1, 2] articles in volume 139 of the Swiss Journal of Palaeontology published with an incorrect article number, this error was caused by a technical problem during publication. This correction article is to publish the incorrect and correct article numbers.

Attachment of oral bacteria to titanium surfaces: An SEM study

1994 ◽  
Vol 52 ◽  
pp. 468-469
Author(s):  
J. E. Laffoon ◽  
R. L. Anderson ◽  
J. C. Keller ◽  
C. D. Wu-Yuan
Keyword(s):  
Technical Problem ◽  
Titanium Implant ◽  
Oral Bacteria ◽  
Bacterial Cells ◽  
Thin Sections ◽  
Surface Ultrastructure ◽  
Sem Study ◽  
Key Factor ◽  
Titanium Surfaces

Titanium (Ti) dental implants have been used widely for many years. Long term implant failures are related, in part, to the development of peri-implantitis frequently associated with bacteria. Bacterial adherence and colonization have been considered a key factor in the pathogenesis of many biomaterial based infections. Without the initial attachment of oral bacteria to Ti-implant surfaces, subsequent polymicrobial accumulation and colonization leading to peri-implant disease cannot occur. The overall goal of this study is to examine the implant-oral bacterial interfaces and gain a greater understanding of their attachment characteristics and mechanisms. Since the detailed cell surface ultrastructure involved in attachment is only discernible at the electron microscopy level, the study is complicated by the technical problem of obtaining titanium implant and attached bacterial cells in the same ultra-thin sections. In this study, a technique was developed to facilitate the study of Ti implant-bacteria interface.Discs of polymerized Spurr’s resin (12 mm x 5 mm) were formed to a thickness of approximately 3 mm using an EM block holder (Fig. 1). Titanium was then deposited by vacuum deposition to a film thickness of 300Å (Fig. 2).

Autoantibodies to Thrombomodulin: Development of an Enzyme Immunoassay and a Survey of their Frequency in Patients with the Lupus Anticoagulant

1992 ◽  
Vol 67 (05) ◽  
pp. 507-509 ◽  
Author(s):  
John Gibson ◽  
Margaret Nelson ◽  
Ross Brown ◽  
Hatem Salem ◽  
Harry Kronenberg
Keyword(s):  
Enzyme Immunoassay ◽  
Lupus Anticoagulant ◽  
Specific Binding ◽  
Technical Problem ◽  
Serum Samples ◽  
Citrate Buffer ◽  
The Mean ◽  
Sample Dilution ◽  
Negative Population ◽  
Serum Components

SummaryIn order to investigate the possibility that autoantibodies to thrombomodulin (TM) may exist in patients with the lupus anticoagulant (LA) and perhaps be implicated in the pathogenesis of recurrent thrombosis seen in such patients, we developed an enzyme-immunoassay to screen serum samples for anti-human TM activity. The major technical problem encountered in developing this assay was to reduce the non-specific binding of serum components from both the LA positive and the negative population. Considerable reduction of non-specific binding was achieved by use of a phosphate/citrate buffer at pH 8.0 and the use of an optimal sample dilution of 1/40. In addition, samples were always tested in parallel in blank wells and results are expressed as an OD ratio. Samples from 113 patients with the LA were assayed and compared to 78 patients referred for LA testing but found to be negative. The mean OD values for the LA positive patients (± SD) was 1.36 (0.44) with a range of 0.78-2.57. This was virtually identical to the values for the LA negative population (1.38 ± 0.40, range 0.76-2.77). The results of this study indicate that there is no evidence for the presence of a significant autoantibody activity to TM in patients with the LA when compared to LA negative patients. If such autoantibodies do exist their frequency must be quite low.

Determination of eddy current losses and hysteresis losses in magnetic circuits of electrical machines

2020 ◽  
pp. 54-58
Author(s):  
S. M. Plotnikov
Keyword(s):  
Eddy Current ◽  
Magnetization Reversal ◽  
Eddy Currents ◽  
Technical Problem ◽  
Electrical Machines ◽  
Eddy Current Losses ◽  
Hysteresis Losses ◽  
Magnetic Circuits ◽  
Core Losses ◽  
Reversal Frequency

The division of the total core losses in the electrical steel of the magnetic circuit into two components – losses dueto hysteresis and eddy currents – is a serious technical problem, the solution of which will effectively design and construct electrical machines with magnetic circuits having low magnetic losses. In this regard, an important parameter is the exponent α, with which the frequency of magnetization reversal is included in the total losses in steel. Theoretically, this indicator can take values from 1 to 2. Most authors take α equal to 1.3, which corresponds to the special case when the eddy current losses are three times higher than the hysteresis losses. In fact, for modern electrical steels, the opposite is true. To refine the index α, an attempt was made to separate the total core losses on the basis that the hysteresis component is proportional to the first degree of the magnetization reversal frequency, and the eddy current component is proportional to the second degree. In the article, the calculation formulas of these components are obtained, containing the values of the total losses measured in idling experiments at two different frequencies, and the ratio of these frequencies. It is shown that the rational frequency ratio is within 1.2. Presented the graphs and expressions to determine the exponent α depending on the measured no-load losses and the frequency of magnetization reversal.

Inside the Enemy's Computer

2017 ◽  
Author(s):  
Clement Guitton
Keyword(s):  
National Security ◽  
Technical Problem ◽  
Technical Information ◽  
Cyber Attack ◽  
Criminal Cases ◽  
Private Companies ◽  
Political Issues ◽  
Current Thinking ◽  
Standards Of Evidence

Attribution — tracing those responsible for a cyber attack — is of primary importance when classifying it as a criminal act, an act of war, or an act of terrorism. Three assumptions dominate current thinking: attribution is a technical problem; it is unsolvable; and it is unique. Approaching attribution as a problem forces us to consider it either as solved or unsolved. Yet attribution is far more nuanced, and is best approached as a process in constant flux, driven by judicial and political pressures. In the criminal context, courts must assess the guilt of criminals, mainly based on technical evidence. In the national security context, decision-makers must analyze unreliable and mainly non-technical information in order to identify an enemy of the state. Attribution in both contexts is political: in criminal cases, laws reflect society’s prevailing norms and powers; in national security cases, attribution reflects a state’s will to maintain, increase or assert its power. However, both processes differ on many levels. The constraints, which reflect common aspects of many other political issues, constitute the structure of the book: the need for judgment calls, the role of private companies, the standards of evidence, the role of time, and the plausible deniability of attacks.

scholarly journals Not all biases are bad: equitable and inequitable biases in machine learning and radiology

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Mirjam Pot ◽  
Nathalie Kieusseyan ◽  
Barbara Prainsack
Keyword(s):  
Machine Learning ◽  
Human Error ◽  
Technical Problem ◽  
Social Dimension ◽  
Patient Treatment ◽  
Technical Solution ◽  
Negative Effects ◽  
Different Types ◽  
Human Decision

AbstractThe application of machine learning (ML) technologies in medicine generally but also in radiology more specifically is hoped to improve clinical processes and the provision of healthcare. A central motivation in this regard is to advance patient treatment by reducing human error and increasing the accuracy of prognosis, diagnosis and therapy decisions. There is, however, also increasing awareness about bias in ML technologies and its potentially harmful consequences. Biases refer to systematic distortions of datasets, algorithms, or human decision making. These systematic distortions are understood to have negative effects on the quality of an outcome in terms of accuracy, fairness, or transparency. But biases are not only a technical problem that requires a technical solution. Because they often also have a social dimension, the ‘distorted’ outcomes they yield often have implications for equity. This paper assesses different types of biases that can emerge within applications of ML in radiology, and discusses in what cases such biases are problematic. Drawing upon theories of equity in healthcare, we argue that while some biases are harmful and should be acted upon, others might be unproblematic and even desirable—exactly because they can contribute to overcome inequities.

scholarly journals The mirroring hypothesis: theory, evidence, and exceptions

2016 ◽  
Vol 25 (5) ◽  
pp. 709-738 ◽  
Author(s):  
Lyra J Colfer ◽  
Carliss Y Baldwin
Keyword(s):  
Problem Solving ◽  
Empirical Studies ◽  
Technical Problem ◽  
Digital Technologies ◽  
Organizational Form ◽  
Cognitive Resources ◽  
Relational Contracts ◽  
Industry Studies ◽  
Hypothesis Theory ◽  
Organizational Ties

Abstract The mirroring hypothesis predicts that organizational ties within a project, firm, or group of firms (e.g., communication, collocation, employment) will correspond to the technical dependencies in the work being performed. This article presents a unified picture of mirroring in terms of theory, evidence, and exceptions. First, we formally define mirroring and argue that it is an approach to technical problem-solving that conserves scarce cognitive resources. We then review 142 empirical studies, divided by organizational form into (i) industry studies, (ii) firm studies, and (iii) studies of open collaborative projects. The industry and firm studies indicate that mirroring is a prevalent pattern but not universal. However, in technologically dynamic industries, partial mirroring, where knowledge boundaries are drawn more broadly than operational boundaries, is likely to be a superior strategy. Firms can also strategically ‘break the mirror’ by implementing modular partitions within their boundaries, or by building relational contracts across their boundaries. Finally, studies of open collaborative projects, most of which focused on software, were not supportive of the hypothesis. We argue that digital technologies make possible new modes of coordination that enable groups to deviate from classical mirroring as seen in firms.

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