Pengantar Ekonomi Makro

Buku ini memang diperuntukan bagi mahasiswa yang mengambil mata kuliah pengantar ekonomi makro di semua jurusan yang mewajibkannya. Materinya dibuat sedemikian rupa agar masing-masing mahasiswa yang mempelajarinya tidak terlalu terkekang dengan jurusan yang diambil. Misalkan pada jurusan administrasi niaga atau sospol, jurusan marketing communication, komputerisasi akuntansi, lain sebagainya. Buku ini pada dasarnya adalah cloning dari buku economics bagian ekonomi makro yang sudah terbit dan edar, akan tetapi pada buku ini ada sedikit perubahan isi , lebih ringkas dan padat

A Signal Processing Method for Assessing Ankle Torque with a Custom-Made Electronic Dynamometer in Participants Affected by Diabetic Peripheral Neuropathy

Portable, custom-made electronic dynamometry for the foot and ankle is a promising assessment method that enables foot and ankle muscle function to be established in healthy participants and those affected by chronic conditions. Diabetic peripheral neuropathy (DPN) can alter foot and ankle muscle function. This study assessed ankle toque in participants with diabetic peripheral neuropathy and healthy participants, with the aim of developing an algorithm for optimizing the precision of data processing and interpretation of the results and to define a reference frame for ankle torque measurement in both healthy participants and those affected by DPN. This paper discloses the software chain and the signal processing methods used for voltage—torque conversion, filtering, offset detection and the muscle effort type identification, which further allowed for a primary statistical report. The full description of the signal processing methods will make our research reproducible. The applied algorithm for signal processing is proposed as a reference frame for ankle torque assessment when using a custom-made electronic dynamometer. While evaluating multiple measurements, our algorithm permits for a more detailed parametrization of the ankle torque results in healthy participants and those affected by DPN

Sign-reversal of the in-plane resistivity anisotropy in hole-doped iron pnictides

The in-plane anisotropy of the electrical resistivity across the coupled orthorhombic and magnetic transitions of the iron pnictides has been extensively studied in the parent and electron-doped compounds. All these studies universally show that the resistivity $\rho_{a}$ across the long orthorhombic axis $a_{O}$ - along which the spins couple antiferromagnetically below the magnetic transition temperature - is smaller than the resistivity $\rho_{b}$ of the short orthorhombic axis $b_{O}$, i. e. $\rho_{a}<\rho_{b}$. Here we report that in the hole-doped compounds Ba$_{1-x}$K$_{x}$Fe$_{2}$As$_{2}$, as the doping level increases, the resistivity anisotropy initially becomes vanishingly small, and eventually changes sign for sufficiently large doping, i. e. $\rho_{b}<\rho_{a}$. This observation is in agreement with a recent theoretical prediction that considers the anisotropic scattering of electrons by spin-fluctuations in the orthorhombic/nematic state.Comment: This paper has been replaced by the new version offering new explanation of the experimental results first reported her

New D1-D5-P geometries from string amplitudes

We derive the long range supergravity fields sourced by a D1-D5-P bound state from disk amplitudes for massless closed string emission. We suggest that since the parameter controlling the string perturbation expansion for this calculation decreases with distance from the bound state, the resulting asymptotic fields are valid even in the regime of parameters in which there is a classical black hole solution with the same charges. The supergravity fields differ from the black hole solution by multipole moments and are more general than those contained within known classes of solutions in the literature, whilst still preserving four supersymmetries. Our results support the conjecture that the black hole solution should be interpreted as a coarse-grained description rather than an exact description of the gravitational field sourced by D1-D5-P bound states in this regime of parameters.Comment: 48 pages, 2 figures, v2: typos correcte

Polarization due to rotational distortion in the bright star Regulus

This is the full published article (retrieved from the 6 months post-publication posting on arXiv) including the Methods and Supplementary Information sections: 33 pages, 10 figures, 8 tablesPolarization in stars was first predicted by Chandrasekhar [1] who calculated a substantial linear polarization at the stellar limb for a pure electron-scattering atmosphere. This polarization will average to zero when integrated over a spherical star but could be detected if the symmetry is broken, for example by the eclipse of a binary companion. Nearly 50 years ago, Harrington and Collins [2] modeled another way of breaking the symmetry and producing net polarization - the distortion of a rapidly rotating hot star. Here we report the first detection of this effect. Observations of the linear polarization of Regulus, with two different high-precision polarimeters, range from +42 parts-per-million (ppm) at a wavelength of 741 nm to -22 ppm at 395 nm. The reversal from red to blue is a distinctive feature of rotation-induced polarization. Using a new set of models for the polarization of rapidly rotating stars we find that Regulus is rotating at 96.5(+0.6/-0.8)% of its critical angular velocity for breakup, and has an inclination greater than 76.5 degrees. The rotation axis of the star is at a position angle of 79.5+/-0.7 degrees. The conclusions are independent of, but in good agreement with, the results of previously published interferometric observations of Regulus [3]. The accurate measurement of rotation in early-type stars is important for understanding their stellar environments [4], and course of their evolution [5].Peer reviewedFinal Accepted Versio

A custom-made electronic dynamometer for evaluation of peak ankle torque after COVID-19

The negative effects of SARS-CoV-2 infection on the musculoskeletal system include symptoms of fatigue and sarcopenia. The aim of this study is to assess the impact of COVID-19 on foot muscle strength and evaluate the reproducibility of peak ankle torque measurements in time by using a custom-made electronic dynamometer. In this observational cohort study, we compare two groups of four participants, one exposed to COVID-19 throughout measurements and one unexposed. Peak ankle torque was measured using a portable custom-made electronic dynamometer. Ankle plantar flexor and dorsiflexor muscle strength was captured for both feet at different ankle angles prior and post COVID-19. Average peak torque demonstrated no significant statistical differences between initial and final moment for both groups (p = 0.945). An increase of 4.8%, p = 0.746 was obtained in the group with COVID-19 and a decrease of 1.3%, p = 0.953 was obtained in the group without COVID-19. Multivariate analysis demonstrated no significant differences between the two groups (p = 0.797). There was a very good test–retest reproducibility between the measurements in initial and final moments (ICC = 0.78, p < 0.001). In conclusion, peak torque variability is similar in both COVID-19 and non-COVID-19 groups and the custom-made electronic dynamometer is a reproducible method for repetitive ankle peak torque measurements

Acute effects of sedentary behavior on ankle torque assessed with a custom-made electronic dynamometer

Inactivity negatively influences general health, and sedentary behaviour is known to impact the musculoskeletal system. The aim of the study was to assess the impact of time spent in active and sedentary behaviour on foot muscle strength. In this observational study, we compared the acute effects of one day of prolonged sitting and one day of low-to-moderate level of activity on ankle torque in one group of eight healthy participants. Peak ankle torque was measured using a portable custom-made electronic dynamometer. Three consecutive maximal voluntary isometric contractions for bilateral plantar flexor and dorsiflexor muscles were captured at different moments in time. The average peak torque significant statistically decreased at 6 h (p = 0.019) in both static and active behaviours, with a higher average peak torque in the active behaviour (p < 0.001). Age, gender, body mass index and average steps did not have any significant influence on the average value of maximal voluntary isometric contraction. The more time participants maintained either static or active behaviour, the less force was observed during ankle torque testation. The static behaviour represented by the sitting position was associated with a higher reduction in the average peak ankle torque during a maximal voluntary isometric contraction when compared to the active behaviour

Proximity of Iron Pnictide Superconductors to a Quantum Tricritical Point

We determine the nature of the magnetic quantum critical point in the doped LaFeAsO using a set of constrained density functional calculations that provide ab initio coefficients for a Landau order parameter analysis. The system turns out to be remarkably close to a quantum tricritical point, where the nature of the phase transition changes from first to second order. We compare with the effective field theory and discuss the experimental consequences.Comment: 4 pages, 4 figure

Household out-of-pocket payments for illness: Evidence from Vietnam

BACKGROUND: In Vietnam, illnesses create high out-of-pocket health care expenditures for households. In this study, the burden of illness in the Bavi district, Vietnam is measured based upon individual household health expenditures for communicable and non-communicable illnesses. The focus of the paper is on the relative effect of different illnesses on the total economic burden of health care on households in general and on households that have catastrophic health care spending in particular. METHODS: The study was performed by twelve monthly follow-up interviews of 621 randomly selected households. The households are part of the FilaBavi project sample – Health System Research Project. The heads of household were interviewed at monthly intervals from July 2001 to June 2002. RESULTS: For the population in the Bavi district, communicable illnesses predominate among the episodes of illness and are the reason for most household health care expenditure. This is the case for almost all groups within the study and for the study population as a whole. However, communicable illnesses are more dominant in the poor population compared to the rich population, and are more dominant in households that have very large, or catastrophic, health care expenditure, compared to those without such expenditures. CONCLUSION: The main findings indicate that catastrophic health care spending for a household is not usually the result of one single disastrous event, but rather a series of events and is related more to "every-day illnesses" in a developing country context than to more spectacular events such as injuries or heart illnesses

The entropy of black holes: a primer

After recalling the definition of black holes, and reviewing their energetics and their classical thermodynamics, one expounds the conjecture of Bekenstein, attributing an entropy to black holes, and the calculation by Hawking of the semi-classical radiation spectrum of a black hole, involving a thermal (Planckian) factor. One then discusses the attempts to interpret the black-hole entropy as the logarithm of the number of quantum micro-states of a macroscopic black hole, with particular emphasis on results obtained within string theory. After mentioning the (technically cleaner, but conceptually more intricate) case of supersymmetric (BPS) black holes and the corresponding counting of the degeneracy of Dirichlet-brane systems, one discusses in some detail the ``correspondence'' between massive string states and non-supersymmetric Schwarzschild black holes.Comment: 51 pages, 4 figures, talk given at the "Poincare seminar" (Paris, 6 December 2003), to appear in Poincare Seminar 2003 (Birkhauser