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

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 $2\le{Z}\le110$ to $2\le{N}\le236$. The calculated results of neutron and proton pairing gap are compared with experimental data using the difference-point formulas $\Delta^{(3)}, \Delta^{(4)}$ and $\Delta^{(5)}$, 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 $\Delta^{(3)}, \Delta^{(4)}$ and $\Delta^{(5)}$ 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