2,504 research outputs found
Strongly separated pairs of core electrons in computed ground states of small molecules
We have performed full configuration interaction computations of the ground
states of the molecules Be, BeH_2, Li, LiH, B, and BH and verified that the
core electrons constitute "separated electron pairs." These separated pairs of
core electrons have nontrivial structure; the core pair does not simply occupy
a single spatial orbital.
Our method of establishing the presence of separated electron pairs is direct
and conclusive. We do not fit a separated pair model; we work with the
wavefunctions of interest directly. To establish that a given group of
spin-orbitals contains a quasi-separated pair, we verify by direct computation
that the quantum state of the electrons that occupy those spin-orbitals is
nearly a pure 2-electron state.Comment: To appear in Computational and Theoretical Chemistr
Effect of hydrolyzed milk on the adhesion of Lactobacilli to intestinal cells
Milk is an essential part of the human diet and is undoubtedly a major calcium source in human nutrition, accepted well by most individuals. Knowledge on how the components from dairy products support or reduce the adherence of probiotics to the intestinal epithelium is limited. The purpose of this study was to investigate the effect of acid-hydrolyzed milk on the adhesion ability of two potentially probiotic strains (Lactobacillus plantarum S2, Lactobacillus gasseri R) to in vitro human intestinal epithelial model consisting of Caco-2 and mucus-secreting HT29-MTX co-culture. The adhesion of our tested strains L. gasseri and L. plantarum was 4.74 and 7.16%, respectively, when using inoculum of 2 × 108 CFU ml–1. Addition of acid-hydrolyzed milk to co-culture decreased the adherence by 53.7% for L. gasseri R and by 62.2% for L. plantarum S2. The results of this study evidently indicate the potential importance of the food matrix as a factor influencing probiotic colonization of the gut
An Object-Oriented Approach to Knowledge Representation in a Biomedical Domain
An object-oriented approach has been applied to the different stages involved in developing a knowledge base about insulin metabolism. At an early stage the separation of terminological and assertional knowledge was made. The terminological component was developed by medical experts and represented in CORE. An object-oriented knowledge acquisition process was applied to the assertional knowledge. A frame description is proposed which includes features like states and events, inheritance and collaboration. States and events are formalized with qualitative calculus. The terminological knowledge was very useful in the development of the assertional component. It assisteed in understanding the problem domain, and in the implementation stage, it assisted in building good inheritance hierarchies
Laboratory-scale anaerobic sequencing batch reactor for treatment of stillage from fruit distillation
This work describes batch anaerobic digestion tests carried out on stillages, the residue of the distillation process on fruit, in order to contribute to the setting of design parameters for a planned
plant. The experimental apparatus was characterized by 3 reactors, each with a useful volume of 5 L.
The different phases of the work carried out were: determining the basic components of the Chemical Oxygen Demand (COD) of the stillages; determining the specific production of biogas; and
estimating the rapidly biodegradable COD contained in the stillages. In particular, the main goal of the anaerobic digestion tests on stillages was to measure the parameters of Specific Gas Production (SGP) and Gas Production Rate (GPR) in reactors in which stillages were being digested using ASBR (Anaerobic Sequencing Batch Reactor) technology. Runs were developed with increasing concentrations of the feed. The optimal loads for obtaining the maximum SGP and GPR values were 8\u20139 gCOD L-1 and 0.9 gCOD g-1VS
500+ Times Faster Than Deep Learning (A Case Study Exploring Faster Methods for Text Mining StackOverflow)
Deep learning methods are useful for high-dimensional data and are becoming
widely used in many areas of software engineering. Deep learners utilizes
extensive computational power and can take a long time to train-- making it
difficult to widely validate and repeat and improve their results. Further,
they are not the best solution in all domains. For example, recent results show
that for finding related Stack Overflow posts, a tuned SVM performs similarly
to a deep learner, but is significantly faster to train. This paper extends
that recent result by clustering the dataset, then tuning very learners within
each cluster. This approach is over 500 times faster than deep learning (and
over 900 times faster if we use all the cores on a standard laptop computer).
Significantly, this faster approach generates classifiers nearly as good
(within 2\% F1 Score) as the much slower deep learning method. Hence we
recommend this faster methods since it is much easier to reproduce and utilizes
far fewer CPU resources. More generally, we recommend that before researchers
release research results, that they compare their supposedly sophisticated
methods against simpler alternatives (e.g applying simpler learners to build
local models)
Recommended from our members
Mechanistic Modeling of Mycobacterium tuberculosis Infection in Murine Models for Drug and Vaccine Efficacy Studies.
Tuberculosis (TB) drug, regimen, and vaccine development rely heavily on preclinical animal experiments, and quantification of bacterial and immune response dynamics is essential for understanding drug and vaccine efficacy. A mechanism-based model was built to describe Mycobacterium tuberculosis H37Rv infection over time in BALB/c and athymic nude mice, which consisted of bacterial replication, bacterial death, and adaptive immune effects. The adaptive immune effect was best described by a sigmoidal function on both bacterial load and incubation time. Applications to demonstrate the utility of this baseline model showed (i) the important influence of the adaptive immune response on pyrazinamide (PZA) drug efficacy, (ii) a persistent adaptive immune effect in mice relapsing after chemotherapy cessation, and (iii) the protective effect of vaccines after M. tuberculosis challenge. These findings demonstrate the utility of our model for describing M. tuberculosis infection and corresponding adaptive immune dynamics for evaluating the efficacy of TB drugs, regimens, and vaccines
Hasil Belajar Kognitif Peserta Didik Melalui Penerapan Model Pembelajaran Inkuiri Berbantuan Media Simulasi PhET Kelas XI IPA SMA Negeri 1 Anggana Materi Fluida Statis
Model pembelajaran inkuiri berbantuan media simulasi PhET adalah suatu tahapan pembelajaran mengikuti langkah-langkah model pembelajaran inkuiri dengan dibantu aplikasi simulasi PhET sebagai laboratorium virtual. Penelitian ini bertujuan untuk mengetahui rata-rata dan peningkatan hasil belajar kognitif peserta didik melalui model pembelajaran inkuiri berbantuan media simulasi PhET pada materi fluida statik. Penelitian ini dilakukan di SMA Negeri 1 Anggana dengan jumlah sampel sebanyak 30 peserta didik pada kelas XI IPA 1. Pengumpulan data dalam penelitian ini menggunakan teknik tes. Berdasarkan hasil penelitian diperoleh nilai rata-rata hasil belajar kognitif peserta didik sebesar 75. Hal ini menunjukkan bahwa rata-rata peserta didik mendapatkan nilai dengan kategori baik. Hasil N-Gain diperoleh rata-rata sebesar 69,7 dengan perolehan 47 % untuk kriteria N-Gain sedang dan perolehan 53 % untuk kriteria N-Gain sedang. Hal ini menunjukan bahwa terdapat peningkatan pada hasil belajar kognitif peserta didik kelas XI IPA 1 materi fluida statik dengan kategori N-Gain sedang
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