849 research outputs found
Second Symposium on Chemical Evolution and the Origin of Life
Recent findings by NASA Exobiology investigators are reported. Scientific papers are presented in the following areas: cosmic evolution of biogenic compounds, prebiotic evolution (planetary and molecular), early evolution of life (biological and geochemical), evolution of advanced life, solar system exploration, and the Search for Extraterrestrial Intelligence (SETI)
Sheehan's like syndrome in a man
An 84-year-old physician self-diagnosed that he had a pituitary tumour when he was found to have a bilateral upper quadrantanopia on routine eye testing. Magnetic resonance imaging (MRI) confirmed a large non-functioning pituitary macroadenoma associated with chiasmal compression. Investigation showed partial hypopituitarism with disconnection hyperprolactinaemia [prolactin 1095 mU/L (60–300)]. He was treated with hormonal replacement consisting of thyroxin 100 µg and prednisolone 3 mg and was offered transphenoidal hypophysectomy, but chose a conservative approach. Two years later, his visual fields worsened (Figure 1A) corresponding to an increase in macrodenoma size. Subsequently, he fell and fractured his left shoulder, which became infected, requiring surgery. Immediately after the shoulder surgery, he became hypotensive and vomited several times, and his visual fields became restricted. MRI showed pituitary infarction (Figure 1B), and he did not require surgical intervention. A few weeks later, he noticed dramatic improvement in his vision. His prolactin level dropped from a peak level of 1095 to 48 mU/L (60–300), suggesting lactotroph infarction. Repeated pituitary MRI showed dramatic reduction in the height of the pituitary macroadenoma consistent with the improvement in his visual fields (Figure 1C)
Quantifying Information Leaks Using Reliability Analysis
acmid: 2632367 keywords: Model Counting, Quantitative Information Flow, Reliability Analysis, Symbolic Execution location: San Jose, CA, USA numpages: 4acmid: 2632367 keywords: Model Counting, Quantitative Information Flow, Reliability Analysis, Symbolic Execution location: San Jose, CA, USA numpages: 4acmid: 2632367 keywords: Model Counting, Quantitative Information Flow, Reliability Analysis, Symbolic Execution location: San Jose, CA, USA numpages: 4We report on our work-in-progress into the use of reliability analysis to quantify information leaks. In recent work we have proposed a software reliability analysis technique that uses symbolic execution and model counting to quantify the probability of reaching designated program states, e.g. assert violations, under uncertainty conditions in the environment. The technique has many applications beyond reliability analysis, ranging from program understanding and debugging to analysis of cyber-physical systems. In this paper we report on a novel application of the technique, namely Quantitative Information Flow analysis (QIF). The goal of QIF is to measure information leakage of a program by using information-theoretic metrics such as Shannon entropy or Renyi entropy. We exploit the model counting engine of the reliability analyzer over symbolic program paths, to compute an upper bound of the maximum leakage over all possible distributions of the confidential data. We have implemented our approach into a prototype tool, called QILURA, and explore its effectiveness on a number of case studie
Housework by Husbands Determinants and Implications
WOMEN continue to carry disproportionate responsibility for household tasks. A study of 650 Detroit women reveals that attitudes, employment status, life cycle, and husband's income all contribute to husband's housework effort. Some evidence is presented that the greater the earnings differential of husband over wife, the less he contributes in help at home.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/67012/2/10.1177_0192513X8100200207.pd
Irreversible and reversible modes of operation of deterministic ratchets
We discuss a problem of optimization of the energetic efficiency of a simple
rocked ratchet. We concentrate on a low-temperature case in which the
particle's motion in a ratchet potential is deterministic. We show that the
energetic efficiency of a ratchet working adiabatically is bounded from above
by a value depending on the form of ratchet potential. The ratchets with
strongly asymmetric potentials can achieve ideal efficiency of unity without
approaching reversibility. On the other hand we show that for any form of the
ratchet potential a set of time-protocols of the outer force exist under which
the operation is reversible and the ideal value of efficiency is also achieved.
The mode of operation of the ratchet is still quasistatic but not adiabatic.
The high values of efficiency can be preserved even under elevated
temperatures
Kinetics of exciton photoluminescence in type-II semiconductor superlattices
The exciton decay rate at a rough interface in type-II semiconductor
superlattices is investigated. It is shown that the possibility of
recombination of indirect excitons at a plane interface essentially affects
kinetics of the exciton photoluminescence at a rough interface. This happens
because of strong correlation between the exciton recombination at the plane
interface and at the roughness. Expressions that relate the parameters of the
luminescence kinetics with statistical characteristics of the rough interface
are obtained. The mean height and length of roughnesses in GaAs/AlAs
superlattices are estimated from the experimental data.Comment: 3 PostScript figure
QCD corrections to the electric dipole moment of the neutron in the MSSM
We consider the QCD corrections to the electric dipole moment of the neutron
in the Minimal Supersymmetric Standard Model. We provide a master formula for
the Wilson coefficients at the low energy scale including for the first time
the mixing between the electric and chromoelectric operators and correcting
widely used previous LO estimates. We show that, because of the mixing between
the electric and chromoelectric operators, the neutralino contribution is
always strongly suppressed. We find that, in general, the effect of the QCD
corrections is to reduce the amount of CP violation generated at the high
scale. We discuss the perturbative uncertainties of the LO computation, which
are particularly large for the gluino-mediated contribution. This motivates our
Next-to-Leading order analysis. We compute for the first time the order alpha_s
corrections to the Wilson coefficients for the gluino contributions, and
recompute the two-loop anomalous dimension for the dipole operators. We show
that the large LO uncertainty disappears once NLO corrections are taken into
account.Comment: 23 pages, 5 figures, added references, corrected typo
Possibilities of use of means of ICT by preparation of final qualification works of students of pedagogical universities
In article problems of readiness of students and professors of mathematical faculties of pedagogical universities for use of means of information and communication technologies in the organization and carrying out researches within final qualification works of bachelors and masters are analyzedВ статье проанализированы проблемы готовности студентов и преподавателей математических факультетов педагогических университетов к использованию средств ИКТ при организации и проведении исследований в рамках выпускных квалификационных работ бакалавра и магистр
The Role of Animal Models for Research on Severe Malaria
The Role of Animal Models for Research on Severe Malari
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