20,742 research outputs found
A Concise Introduction to Perturbation Theory in Cosmology
We give a concise, self-contained introduction to perturbation theory in
cosmology at linear and second order, striking a balance between mathematical
rigour and usability. In particular we discuss gauge issues and the active and
passive approach to calculating gauge transformations. We also construct
gauge-invariant variables, including the second order tensor perturbation on
uniform curvature hypersurfaces.Comment: revtex4, 16 pages, 3 figures; v2: minor changes, typos corrected,
reference added, version accepted by CQ
Dai Sebagai Ulama Pewaris Para Nabi
Allah guides people through the presence of the messengers who served as a witness, to give glad tidings and warnings, the Caller of Allah, to teach the Qur'an and the wisdom and to be good role models for human beings. However, as the messenger was gone, the task of the apostles passed on to the scholars or preachers whose task is to invite people to the path of Allah. Therefore, the scholars and preachers, as the spearhead of the spread of Islam, need to know the tasks of the Prophet and also follow the example of the Prophet in carrying out the mandate Allah assigned to him. Allah memberikan petunjuk kepada manusia melalui kehadiran para rasul yang bertugas untuk menjadi saksi, memberikan kabar gembira dan peringatan, penyeru agama Allah, mengajarkan al-Qur'an dan hikmah serta menjadi suri tauladan yang baik bagi manusia. Namun, ketika rasul sudah tiada, maka tugas rasul tersebut diwariskan kepada para ulama atau dai yang bertugas untuk mengajak manusia kepada jalan Allah. Oleh karena itu, dai sebagai ujung tombak penyebaran Islam perlu mengetahui tugas-tugas para Nabi dan juga mencontoh Nabi dalam mengemban amanat Allah yang dibebankan kepadanya
Does autonomic function link social position to coronary risk? The Whitehall II study.
BACKGROUND: Laboratory and clinical studies suggest that the autonomic nervous system responds to chronic behavioral and psychosocial stressors with adverse metabolic consequences and that this may explain the relation between low social position and high coronary risk. We sought to test this hypothesis in a healthy occupational cohort. METHODS AND RESULTS: This study comprised 2197 male civil servants 45 to 68 years of age in the Whitehall II study who were undergoing standardized assessments of social position (employment grade) and the psychosocial, behavioral, and metabolic risk factors for coronary disease previously found to be associated with low social position. Five-minute recordings of heart rate variability (HRV) were used to assess cardiac parasympathetic function (SD of N-N intervals and high-frequency power [0.15 to 0.40 Hz]) and the influence of sympathetic and parasympathetic function (low-frequency power [0.04 to 0.15 Hz]). Low employment grade was associated with low HRV (age-adjusted trend for each modality, P< or =0.02). Adverse behavioral factors (smoking, exercise, alcohol, and diet) and psychosocial factors (job control) showed age-adjusted associations with low HRV (P<0.03). The age-adjusted mean low-frequency power was 319 ms2 among those participants in the bottom tertile of job control compared with 379 ms2 in the other participants (P=0.004). HRV showed strong (P<0.001) linear associations with components of the metabolic syndrome (waist circumference, systolic blood pressure, HDL cholesterol, triglycerides, and fasting and 2-hour postload glucose). The social gradient in prevalence of metabolic syndrome was explained statistically by adjustment for low-frequency power, behavioral factors, and job control. CONCLUSIONS: Chronically impaired autonomic function may link social position to different components of coronary risk in the general population
Abelian 2-form gauge theory: superfield formalism
We derive the off-shell nilpotent Becchi-Rouet-Stora-Tyutin (BRST) and
anti-BRST symmetry transformations for {\it all} the fields of a free Abelian
2-form gauge theory by exploiting the geometrical superfield approach to BRST
formalism. The above four (3 + 1)-dimensional (4D) theory is considered on a
(4, 2)-dimensional supermanifold parameterized by the four even spacetime
variables x^\mu (with \mu = 0, 1, 2, 3) and a pair of odd Grassmannian
variables \theta and \bar\theta (with \theta^2 = \bar\theta^2 = 0, \theta
\bar\theta + \bar\theta \theta = 0). One of the salient features of our present
investigation is that the above nilpotent (anti-)BRST symmetry transformations
turn out to be absolutely anticommuting due to the presence of a Curci-Ferrari
(CF) type of restriction. The latter condition emerges due to the application
of our present superfield formalism. The actual CF condition, as is well-known,
is the hallmark of a 4D non-Abelian 1-form gauge theory. We demonstrate that
our present 4D Abelian 2-form gauge theory imbibes some of the key signatures
of the 4D non-Abelian 1-form gauge theory. We briefly comment on the
generalization of our supperfield approach to the case of Abelian 3-form gauge
theory in four (3 + 1)-dimensions of spacetime.Comment: LaTeX file, 23 pages, journal versio
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Electrospray synthesis of PLGA TIPS microspheres
We successfully demonstrate the synthesis of polymer microspheres using a single electrospray source, and show their physical characterisation. Electrospray has proven to be a versatile method to manufacture particles, giving tight control over size with quasi-monodisperse size distributions. It is a liquid atomisation technique that generates a monodisperse population of highly charged liquid droplets over a broad size range (nanometres to tens of microns). The droplets contain liquid precursors for the in-flight synthesis of particles, and control over the trajectory of these droplets can be precisely manipulated with the use of electric fields to drive them to a grounded substrate. This study reports a method to synthesize poly(lactic-co-glycolic) acid (PLGA) microspheres using the electrospray and thermally induced phase separation (TIPS) techniques, followed by subsequent freeze-drying, for particle production. These microspheres are of interest as vehicles for controlled drug release systems
Compositional nonblocking verification with always enabled events and selfloop-only events
This paper proposes to improve compositional nonblocking verification through the use of always enabled and selfloop-only events. Compositional verification involves abstraction to simplify parts of a system during verification. Normally, this abstraction is based on the set of events not used in the remainder of the system, i.e., in the part of the system not being simplified. Here, it is proposed to exploit more knowledge about the system and abstract events even though they are used in the remainder of the system. Abstraction rules from previous work are generalised, and experimental results demonstrate the applicability of the resulting algorithm to verify several industrial-scale discrete event system models, while achieving better state-space reduction than before
A Deep Learning-Based Privacy-Preserving Model for Smart Healthcare in Internet of Medical Things Using Fog Computing
With the emergence of COVID-19, smart healthcare, the Internet of Medical Things, and big data-driven medical applications have become even more important. The biomedical data produced is highly confidential and private. Unfortunately, conventional health systems cannot support such a colossal amount of biomedical data. Hence, data is typically stored and shared through the cloud. The shared data is then used for different purposes, such as research and discovery of unprecedented facts. Typically, biomedical data appear in textual form (e.g., test reports, prescriptions, and diagnosis). Unfortunately, such data is prone to several security threats and attacks, for example, privacy and confidentiality breach. Although significant progress has been made on securing biomedical data, most existing approaches yield long delays and cannot accommodate real-time responses. This paper proposes a novel fog-enabled privacy-preserving model called [Formula: see text] sanitizer, which uses deep learning to improve the healthcare system. The proposed model is based on a Convolutional Neural Network with Bidirectional-LSTM and effectively performs Medical Entity Recognition. The experimental results show that [Formula: see text] sanitizer outperforms the state-of-the-art models with 91.14% recall, 92.63% in precision, and 92% F1-score. The sanitization model shows 28.77% improved utility preservation as compared to the state-of-the-art
Proton and Neutron Pairing Properties within a mixed volume-surface pairing force using SKI3-HFB Theory
This work aims at a systematic investigations of the pairing properties and
Fermi properties from the proton drip-line to the neutron drip-line. In order
to provide more accurate mass formula with skyrme SKI3 force, the global
descriptive power of the SKI3-HFB model for pairing properties are made in this
study. Systematic Skyrme SKI3-Hartree-Fock-Bogoliubov calculations with a mixed
volume-surface pairing force are carried out to study the ground-state neutron
and proton pairing gap, neutron and proton pairing energy and neutron and
proton Fermi energy for about 2095 even-even nuclei ranging from to . The calculated results of neutron and proton pairing gap
are compared with experimental data using the difference-point formulas
and , and also compared with the
neutron and proton pairing gap of Lipkin-Nogami model. It is shown that the
Skyrme-SKI3 functional with the mixed volume-surface pairing force can be
successfully used for describing the ground-state pairing and Fermi properties
of the investigated nuclei, in particularly the neutron-rich nuclei and the
exotic nuclei near the neutron drip-line. On the other hand, the calculated
neutron and proton pairing gap are in good agreement with the available
experimental values of the neutron and proton pairing gap of the
difference-point formulas and and
with the data of Lipkin-Nogami model over the whole nuclear chart.Comment: 18 pages, 9 figure
Maximising the acquisition of core communication skills at the start of medical training
Background Clinical communication teaching for medical undergraduates may involve real patient contact alongside simulated patient contact. However, there is still comparatively little known about the experience of learning with real patients and how that may impact on the simulated patient encounter. Aim To explore the impact of real patient contact on the experience of communication skills training and simulated patient contact for first year medical undergraduate students. Methods As part of the six-year MBBS undergraduate medical degree at Imperial College London, students are obliged to undertake communication skills training, which involves teaching with simulated and real patients. In 2017 (toward the end of formal teaching), a small sample of Year 1 medical students, who had taken part in extra-curricular teaching with real patients were recruited for the study to compare their performance with a control group in a simulated patient encounter. The performance of both groups was analysed alongside follow up focus group data from a sample of the study group. Results Quantitative analysis revealed there was no significant difference in communication skills during a scored simulated patient interview between students with real patient contact and those without. Focus group data, however, revealed valuable insights into the experience of learning with real patients. Students reported a marked increase in their confidence and ability to naturalise their communication skills as a result of real patient contact. Students also reported that skills gained through real patient contact may not always transfer easily to the simulated patient setting. Conclusion Real patient contact is an invaluable component of communication training for undergraduate medical students. For successful implementation there needs to be a clear curricular purpose at pedagogical, practical and organisational levels. Students’ experience of real patient contact can provide an informed foundation upon which to implement other modes of teaching. Keywords: Real patient contact, Communication skills training, Early years curriculu
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