1,254 research outputs found
Non-axisymmetric oscillations of stratified coronal magnetic loops with elliptical cross-sections
We study non-axisymmetric oscillations of a straight magnetic tube with an
elliptic cross-section and density varying along the tube. The governing
equations for kink and fluting modes in the thin tube approximation are
derived. We found that there are two kink modes, polarised along the large and
small axes of the elliptic cross-section. We have shown that the ratio of
frequencies of the first overtone and fundamental harmonic is the same for both
kink modes and independent of the ratio of the ellipse axes. On the basis of
this result we concluded that the estimates of the atmospheric scale height
obtained using simultaneous observations of the fundamental harmonic and first
overtone of the coronal loop kink oscillations are independent of the
ellipticity of the loop cross-section
Three-dimensional coronal slow modes: toward three-dimensional seismology
On 2008 January 10, the twin Solar Terrestrial Relations Observatory (STEREO) A and B spacecraft conducted a high time cadence study of the solar corona with the Extreme UltraViolet Imager (EUVI) instruments with the aim of investigating coronal dynamics. Observations of the three-dimensional propagation of waves within active region coronal loops and a measurement of the true coronal slow mode speed are obtained. Intensity oscillations with a period of approximately 12 minutes are observed to propagate outwards from the base of a loop system, consistent with the slow magnetoacoustic mode. A novel analysis technique is applied to measure the wave phase velocity in the observations of the A and B spacecraft. These stereoscopic observations are used to infer the three-dimensional velocity vector of the wave propagation, with an inclination of 37 +- 6 deg to the local normal and a magnitude of 132 +- 9 and 132 +- 11 km s-1, giving the first measurement of the true coronal longitudinal slow mode speed, and an inferred temperature of 0.84 +- 12 MK and 0.84 +- 15 MK
Observational evidence favors a resistive wave heating mechanism for coronal loops over a viscous phenomenon
Context. How coronal loops are heated to their observed temperatures is the subject of a long standing debate.
Aims. Observational evidence exists that the heating in coronal loops mainly occurs near the loop footpoints. In this article, analytically and numerically obtained heating profiles produced by resonantly damped waves are compared to the observationally estimated profiles.
Methods. To do that, the predicted heating profiles are fitted with an exponential heating function, which was also used to fit the observations. The results of both fits, the estimated heating scale heights, are compared to determine the viability of resonant absorption as a heating mechanism for coronal loops.
Results. Two results are obtained. It is shown that any wave heating mechanism (i.e. not just resonant absorption) should be dominated by a resistive (and not a viscous) phenomenon in order to accomodate the constraint of footpoint heating. Additionally it is demonstrated that the analytically and numerically estimated heating scale heights for the resonant absorption damping mechanism
fit the observations very well
Pengaruh Penyuluhan Tentang Senam Hamil Terhadap Peningkatan Pengetahuan Ibu Hamil
Latar Belakang : Pelayanan Antenatal care (ANC) adalah pelayanan kesehatan oleh tenaga kesehatan untuk ibu selama masa kehamilannya, dilaksanakan sesuai standar pelayanan antenatal yang ditetapkan dalam standar pelayanan kebidanan yang meliputi anamnesis, pemeriksaan fisik (umum dan kebidanan), pemeriksaan laboratorium rutin dan khusus, serta intervensi umum dan khusus sesuai resiko yang ditemukan dalam pemeriksaan Standar waktu pelayanan antenatal tersebut untuk menjamin perlindungan pada ibu hamil, berupa deteksi dini faktor resiko, pencegahan dan penanganan komplikasi termasuk didalamnya pelaksanaan senam hamilTujuan : Penelitian ini bertujuan untuk mengetahui pengaruh penyuluhan tentang mobilisasi Jenis Penelitian : Penelitian eksperimen ini menggunakan desain penelitian one group pretes – posttes dimna akan di lakukan observasi pertama (pre tes) sehingga peneliti dapat menguji Perubahan Perubahan yang terjadi setelah adanya perlakuan, tapi dalam desain ini tidak ada kelompok pembanding.Hasil : Dari hasil penelitian yang di analisis denngan menggunakan uji Paired Sample T-Test berdasarkan tabel Paired Sample Statistic menunjukkan bahwa nilai yang diperoleh dari pengetahuan ibu sebelum diberikan penyuluhan nilai mean 8,25 mengalami peningkatan setelah diberikan penyuluhan menjadi nilai mean 15,11 hasil uji t didapatkan nilai hitung -12,637 dan signifikansi p = 0,000 ( p < 0,05 )
The formation of postcolonial theory
The purpose of this article is to outline certain options and struggles, which gave rise to postcolonial theory. The author deals with various experiences of anti-slavery and anti-colonial movements in Western and tricontinental countries, comprising the development of postcolonial theory. It is argued that postcolonial theory provides a means of defiance by which any exploitative and discriminative practices, regardless of time and space, can be challenged. The article consists of a section in which terminology is clarified, secondly a discussion of the elements that functioned asjustification of the formation of postcolonial theory, namely a humanitarian, economic, political, and religious justification. The role of feminism and anti-colonialism is discussed in the third instance, followed by a reflection on the concept “hybrid identities”
Pre-incubation of cell-free HIV-1 group M isolates with non-nucleoside reverse transcriptase inhibitors blocks subsequent viral replication in co-cultures of dendritic cells and T cells.
In order to study the inhibitory effect of various reverse transcriptase inhibitors (RTIs) on cell-free HIV, we adapted a recently described in vitro system, based on co-cultures of dendritic cells and resting CD4 T cells, modelling early target cells during sexual transmission. The compounds tested included the second-generation non-nucleoside RTI (NNRTI) TMC-120 (R147681, dapivirine) and TMC-125 (R165335, travertine), as well as the reference nucleoside RTI AZT (zidovudine), the nucleotide RTI PMPA (tenofovir) and the NNRTI UC-781. The virus strains included the reference strain HIV-1Ba-L and six primary isolates, representative of the HIV-1 group M pandemic. They all display the non-syncytium-inducing and CCR5 receptor-using (NSI/R5) phenotype, important in transmission. Cell-free virus was immobilized on a poly-L-lysine (PLL)-treated microwell plate and incubated with compound for 1 h. Afterwards, the compound was thoroughly washed away; target cells were added and cultured for 2 weeks, followed by an extended culture with highly susceptible mitogen-activated T cells. Viral production in the cultures was measured on supernatant with HIV antigen ELISA. Negative results were confirmed by showing absence of proviral DNA in the cells. TMC-120 and TMC-125 inhibited replication of HIV-1Ba-L with average EC50 values of 38 nM and 117 nM, respectively, whereas the EC50 of UC-781 was 517 nM. Complete suppression of virus and provirus was observed at compound concentrations of 100, 300 and 1000 nM, respectively. Inhibition of all primary isolates followed the same pattern as HIV-1Ba-L. In contrast, pre-treating the virus with the nucleotide RTI PMPA and AZT failed to inhibit infection even at a concentration of 100000 nM. These data clearly suggest that NNRTIs inactivate RT enzymatic activity of different viral clades (predominant in the epidemic) and might be proposed for further testing as a sterilizing microbicide worldwide
Transverse oscillations of two parallel coronal loops
Context. Collective oscillations of two or more coronal magnetic loops are observed very often.
Aims. We study the eigenmodes of oscillations of a system consisting of two parallel magnetic loops.
Methods. The linearised MHD equations for a cold plasma are solved analytically in bicylindrical coordinates using the longwavelength approximation. A dispersion equation determining the frequencies of eigenmodes is derived and solved analytically.
Results. Two solutions of the dispersion relation were found. The higher frequency corresponds to the antisymmetric mode polarised in the direction parallel to the line connecting the loop centres, and the symmetric mode polarised in the perpendicular direction.
Depending on the polarisation of modes corresponding to the lower frequency, the systems of two parallel loops are classified as standard and anomalous. In standard systems the lower frequency corresponds to the symmetric mode polarised in the direction parallel to the line connecting the loop centres, and the antisymmetric mode polarised in the perpendicular direction. In anomalous systems
the lower frequency corresponds to the antisymmetric mode polarised in the direction parallel to the line connecting the loop centres, and the symmetric mode polarised in the perpendicular direction. The limiting case of two identical loops is studied. The results for this case are compared with recent numerical results
Formulary management activities and practice implications among public sector hospital pharmaceutical and therapeutics committees in a South African province
Introduction: The World Health Organization identified Pharmaceutical and Therapeutics Committees (PTCs) at district and hospital levels as one of the pivotal models to promote rational use of medicines (RUM). This is endorsed by the Government in South Africa. Formulary development and management is one of the main functions of PTCs. This study aimed to describe the formulary management activities among PTCs in public hospitals in Gauteng Province, South Africa, following initiatives to promote RUM in South Africa. Methods: Qualitative, nonparticipatory, observational study, observing 26 PTC meetings. Data were coded and categorized using NVivo9 ® qualitative data analysis software. Themes and sub-themes were developed. The themes and sub-themes on formulary management are the principal focus of this paper. Results: More than half of the observed PTCs reviewed their formulary lists. There was variation in the review process among institutions providing different levels of care. Various aspects were considered for formulary management especially requests for medicines to be added. These included cost considerations (mainly focusing on acquisition costs), evidence-based evaluation of clinical trials, patient safety, clinical experience and changes in the National Essential Medicines List (NEML). The tertiary PTCs mostly dealt with applications for new non-EML medicines, while PTCs in the other hospitals mainly requested removal or addition of EML medicines to the list. Conclusion: This is the first study from Gauteng Province, South Africa, reporting on how decisions are actually taken to include or exclude medicines onto formularies within public sector hospitals providing different levels of care. Various approaches are adopted at different levels of care when adding to- or removing medicines from the formulary lists. Future programs should strengthen PTCs in specialized aspects of formulary management. A more structured approach to formulary review at the local PTC level should be encouraged in line with the national approach when reviewing possible additions to the NEML
KANDUNGAN ESCHERICHIA COLI DAN KONDISI FISIK SUMUR GALI DI KELURAHAN KAKASKASEN III LINGKUNGAN III KECAMATAN TOMOHON UTARA KOTA TOMOHON
Sumber air bersih yang digunakan penduduk di Indonesia umumnya yaitu sumur gali terlindung (29%), sumur pompa (24%), dan air ledeng/PDAM (19%). Air sumur gali beresiko tercemar E.coli bila lokasi sumur terletak dekat dengan sumber pencemar dan /atau memiliki kondisi fisik yang tidak sesuai dengan syarat kesehatan. Tujuan dari penelitian ini untuk mengetahui kandungan E.coli air sumur gali dan kondisi fisik sumur gali di Kelurahan Kakaskasen III Lingkungan III Kecamatan Tomohon Utara Kota Tomohon. Penelitian ini merupakan survey deskriptif berbasis laboratorium. Populasi berjumlah 68 sumur. Sampel berjumlah 20 sampel sumur yang diperoleh secara purposive sampling. Kandungan E.coli ditentukan melalui pemeriksaan laboratorium. Kondisi fisik sumur gali ditentukan menggunakan instrumen check list. Data dianalisis secara deskriptif berpatokan pada distribusi frekuensi dan persentase. Hasil penelitian menunjukkan bahwa dari 20 sampel air sumur gali terdapat 1 sampel (5%) yang positif mengandung E.coli dan 19 sampel (95%) tidak mengandung E.coli. terdapat 15 sumur gali (75%) yang kondisi fisiknya tidak memenuhi syarat dan 5 lainnya (25%) memenuhi syarat. Kesimpulan penelitian ini yaitu 1 sumur galli (5%) mengandung E.coli sehingga tidak memenuhi syarat kesehatan. Terdapat 15 sumur gali (75%) memiliki kondisi fisik yang tidak sesuai degan persyaratan kesehatan dengan demikian beresiko tercemar.Kata Kunci: Sumur Gali, Kandungan EscherichiaColi, Kondisi FisikABSTRACTSource of clean water that generally used by public in Indonesia was protected dug wells (29 %), pump well (24 %), tap water/PDAM (19%). Dug well water has risk of being contaminated by E.coli if the well is located near the polluter source and/or has inappropriate physical condition with health requirement. The objective of this research is to find out about E.coli's content of dug well water and physical condition of dug well water in Kakaskasen III Ward III Subdistrict North Tomohon Subdistrict, Tomohon City. This research is descriptive survey laboratory-based. Total population 68 wells. Total sample 20 wells obtained by purposive sampling. E.coli content determined by laboratory- test. Physical condition of dug well determined by using check list instrument. Descriptive data analysis based on frequency distribution and percentage.The result of the research showed that from 20 samples of dug wells water there was 1 sample (5 %) positively contain E.coli and 19 samples (95 %) does not contain E.coli. There was 15 dug wells (75%) that the physical condition inappropriate with the requirement and the other 5 (25%) is appropriate. The conclusion of this research was 1 (5%) dug well contain E.coli so that it was inappropriate with health requirements. There was 15 (75 %) dug wells has physical condition that inapproriate with health requirements so that has a risk of being contaminated.Keywords:Well Dug, Escherichia coli Content, Physic Conditio
Kink oscillations of cooling coronal loops with variable cross-section
We study kink waves and oscillations in a thin expanding magnetic tube in the presence of flow. The tube consists of a core region and a thin transitional region at the tube boundary. In this region the plasma density monotonically decreases from its value in the core region to the value outside the tube. Both the plasma density and velocity of background flow vary along the tube and in time. Using the multiscale expansions we derive the system of two equations describing the kink oscillations. When there is no transitional layer the oscillations are described by the first of these two equations. We use this equation to study the effect of plasma density variation with time on kink oscillations of an expanding tube with a sharp boundary. We assume that the characteristic time of the density variation is much greater than the characteristic time of kink oscillations. Then we use the Wentzel-Kramer-Brillouin (WKB) method to derive the expression for the adiabatic invariant, which is the quantity that is conserved when the plasma density varies. The general theoretical results are applied to the kink oscillations of coronal magnetic loops. We consider an expanding loop with the half-circle shape and assume that the plasma temperature inside a loop decays exponentially with time. We numerically calculated the dependences of the fundamental mode frequency, the ratio of frequencies of the first overtone and fundamental mode, and the oscillation amplitude on time. We obtained that the oscillation frequency and amplitude increase and the frequency ratio decreases due to cooling. The amplitude increase is stronger for loops with a greater expansion factor. This effect is also more pronounced for higher loops. However, it is fairly moderate even for loops that are quite high
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