912 research outputs found
Collapse and revivals for the binomial field distribution
The exact representation of the atomic inversion in the Jaynes-Cummings model
as an integral over the Hankel contour is used. For a field in a binomial
state, the integral is evaluated using the saddle point method. Simple
approximate analytical expressions for collapse and revivals are obtained.Comment: 5 pages, 1 figures. arXiv admin note: substantial text overlap with
arXiv:2307.0783
Logistic Knowledge Tracing: A Constrained Framework for Learner Modeling
Adaptive learning technology solutions often use a learner model to trace
learning and make pedagogical decisions. The present research introduces a
formalized methodology for specifying learner models, Logistic Knowledge
Tracing (LKT), that consolidates many extant learner modeling methods. The
strength of LKT is the specification of a symbolic notation system for
alternative logistic regression models that is powerful enough to specify many
extant models in the literature and many new models. To demonstrate the
generality of LKT, we fit 12 models, some variants of well-known models and
some newly devised, to 6 learning technology datasets. The results indicated
that no single learner model was best in all cases, further justifying a broad
approach that considers multiple learner model features and the learning
context. The models presented here avoid student-level fixed parameters to
increase generalizability. We also introduce features to stand in for these
intercepts. We argue that to be maximally applicable, a learner model needs to
adapt to student differences, rather than needing to be pre-parameterized with
the level of each student's ability
Student Modeling Based on Fine-Grained Programming Process Snapshots
ICER '17 Proceedings of the 2017 ACM Conference on International Computing Education Research. New York, NY, USA : ACM, 2017 ISBN: 978-1-4503-4968-0I am studying the use of fine-grained programming process data for student modeling. The initial plan is to construct different types of program state representations such as Abstract Syntax Trees (ASTs) from the data. These program state representations could be used for both automatically inferring knowledge components that the students are trying to learn as well as for modeling students' knowledge on those specific components.Peer reviewe
IS900 Restriction Fragment Length Polymorphism (RFLP) Analysis of Mycobacterium avium subsp. paratuberculosis Isolates from Goats and Cattle in Norway
In Norway, paratuberculosis has been frequently diagnosed in goats, while cattle have been almost free of the infection. This difference in prevalence between goats and cattle has led to speculations about the existence of a Mycobacterium avium subsp. paratuberculosis (M. a. paratuberculosis) isolate that is non-pathogenic for cattle. There is little information available on genotypic variation of M. a. paratuberculosis isolated from animals in Norway. In the present study, genotypic information on 51 isolates from goats and four isolates from cattle in Norway was obtained by use of IS900 restriction fragment length polymorphism (RFLP) analysis. All isolates from cattle and 84% of the isolates from goats had the same RFLP pattern (B-C1). Five RFLP patterns not previously detected were found. No genotypic variation that could explain a difference in host origin was found between the isolates from cattle and the majority of the Norwegian goat isolates. This lack of difference indicates that the most common M. a. paratuberculosis isolates in Norway may infect both cattle and goats
Tuberculous lesions in pigs in the Czech Republic in the years 1990-1999
In the Czech Republic, bovine tuberculosis in cattle was controlled in 1968. The last outbreak was diagnosed in cattle and domestic pigs in 1995. During the veterinary hygiene inspection of pigs slaughtered in slaughterhouses, however, tuberculous lesions were still being found above all in the head and intestinal lymph nodes. In the decade monitored a total of 45 873 318 pigs were slaughtered and examined according to veterinary hygiene standards. Apart from 1991, when results of tuberculous findings were not obtained, tuberculous lesions were found in 134 088 (0.32%) of the 41 458 565 pigs examined in the remaining nine years. During a detailed analysis of the pathological anatomical examination of 190 940 pigs slaughtered in one district, tuberculous lesions in lymph nodes were found in 4 107 (2.2%) pigs: mesenteric (65.3% pigs), submandibular (18.6% pigs), inguinal (0.1% pigs) and simultaneously intestinal and head lymph nodes (15.9% pigs). Miliary tuberculosis was found only in the parenchymatous organs of four (0.1%) pigs. The following financial losses resulted: 6% for confiscating the head, intestines and stomach, and 22 to 24% for assessing meat as conditionally edible after processing, i.e. intended only for heat-processed products. Mycobacteria were isolated from 7 246 (41.8%) pigs through the cultivation of tissue samples from 17 326 pigs. Mycobacterium bovis was detected in only five (0.07%) animals which originated from the last outbreak of bovine tuberculosis in cattle in the Czech Republic in 1995. M. avium complex (MAC) isolates came from 6 870 (94.8%) animals: 55.7% M. a. avium isolates were mainly of serotypes 2 and 3 and genotype IS901+ and IS1245+ and 39.2% M. a. hominissuis isolates were mainly of serotypes 4, 8 and 9 and genotype IS901- and IS1245+. Conditionally pathogenic mycobacteria (M. chelonae, M. terrae, M. phlei and M. fortuitum) were isolated from 371 (5.1%) pigs. In the whole period monitored, two marked increases In the findings of tuberculous lesions were recorded: In the mid-1990s as a result of using deep bedding with wood shavings and at the end of the 1990s as a result of supplementing the pigs’ feed with peat
The language of instruction: Compensating for challenge in lectures.
Recent studies have used Coh-Metrix, an automated text analyzer, to assess differences in language characteristics across different genres and academic disciplines (Graesser, McNamara, & Kulikowich, 2011; McNamara, Graesser, McCarthy, & Cai, 2014). Coh-Metrix analyzes text on many constructs at different levels, including Word Concreteness (vs. abstractness), Narrativity (vs. informational), Deep Cohesion, Referential Cohesion, and Syntactic Simplicity. In previous research, texts in the natural sciences had lower Narrativity and Word Concreteness than texts in the language arts, but were higher in Syntactic Simplicity and Referential Cohesion. This pattern suggests a form of compensation in which difficulty on one dimension (e.g., Word Concreteness) is compensated for by increasing text ease on another dimension (e.g., Syntactic Simplicity). In the present study, we provide a further test of this compensation idea by analyzing oral language use across humanities and natural science lectures. We demonstrate that decreases in Word Concreteness across lectures are associated with increases in Narrativity, Deep Cohesion, and Syntactic Simplicity. In addition, within lectures, decreases in Word Concreteness are associated with increases in Syntactic Simplicity. Compensatory mechanisms are discussed in this article at different levels of language and discourse
ГОСТРИЙ ІНФАРКТ МІОКАРДА. ОБОВ’ЯЗКИ МЕДИЧНОЇ СЕСТРИ ПРИ ЛІКУВАННІ ІНФАРКТУ МІОКАРДА
The work of nurses of Cardiology Department is very important. They are responsible for providing care in Cardiology, accurate execution of doctor’s appointments, fast and professional providing of the first aid, and conducting resuscitation in an emergency. All of this demands the great knowledge and practical skills in nursing to its moral aspect, the correct behavior in a team, when communicating with patients and their relatives.Значення діяльності медсестри кардіологічного відділення досить велике. Вона відповідає за надання допомоги кардіологічним хворим, чітке виконання призначень лікаря, швидке і професійне надання долікарської допомоги, проведення реанімаційних заходів в екстрених випадках. Все це вимагає високого рівня знань і практичних навичок медичної сестри, вміння поводитися в колективі, при спілкуванні з хворими та їх родичами
Comparative evaluation of laparoscopic liver resection for posterosuperior and anterolateral segments
Mycobacterial contamination of environment in pig farms in the Czech Republic between 1996 and 2002
The purpose of this study was to find source of mycobacterial infections in pig farms. A total of 2 411 environmental samples (bedding materials, water, biofilm from pipelines, peat, etc.) were examined by microscopy and culture. Isolates were identified by serotyping and PCR. Mycobacteria were isolated from 579 (24.0%) samples. 47.0% isolates were Mycobacterium avium subsp. hominissuis isolates (IS901-, IS1245+, serotypes 4, 6, 8, 9), 2.2% isolates were M. a. avium (IS901+, IS1245+, serotype 2) and 50.8% belong to atypical mycobacteria comprising of fifteen species. The frequent isolates were found in peat samples (213/65.1%) in which 81.2% isolates comprised M. a. hominissuis. High amount of mycobacteria were isolated from biofilm (36.4%) and water (29.6%). Alike peat, non-pathogenic species were predominant. The third sources of mycobacteria were bedding materials, mostly sawdust (43.6%). Presence of mycobacteria in the animals’ environment leads to economic losses due to meat condemnation in abattoirs
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