120 research outputs found
Teacher knowing or not knowing about students
Based on a critical ethnography of an urban high school that exemplifies the many changes of post-apartheid South Africa, this paper presents data about two teachers who propose opposing perspectives and practices of knowing students. The analysis of the teachers’ narratives shows that they came to know their students through solicited, unsolicited and professional knowing processes. A surprise finding for successful teaching, in what may be considered difficult yet not uncommon conditions of schooling in South Africa, is that knowing about students can be dangerous, and that not knowing students can be useful for teachers. These counter-intuitive findings are generative of questions requiring further exploration.Keywords: critical ethnography; not knowing students; successful teaching; teacher knowing; urban schoo
Maternal mortality in tertiary care hospital: a 2-year review
Background: Epidemiological data pertaining to maternal mortality is valuable in each set up to design interventional programs to favourably reduce the ratio. This study was done to evaluate the maternal mortality rate in our hospital, to assess the epidemiological aspects and causes of maternal mortality, and to suggest recommendations for improvement.Methods: This was a 2-year retrospective study. Epidemiological data was collected from the Last 2 years of Facility Based Maternal Death Review Form. Maternal mortality ratio, epidemiological factors and causes affecting maternal mortality were assessed.Results: A total of 72 maternal deaths occurred. Most maternal deaths occurred in the age group of 20–24 years (40.27%), multiparous women (70.83%), women from rural areas (65.27%), illiterate women, unbooked patients (83.33%), and patients of low socioeconomic status. Direct causes accounted for 62.4% of maternal deaths where as 37.4% of maternal deaths were due to indirect causes.Conclusions: There is a wide scope for improvement as a large proportion of the observed deaths could be preventable
Comparative pharmaceutical and analytical study of Kasisadi Ghrita prepared by two different methods
Introduction: Sneha Kalpana are the dosage forms which can be used both internally as well as externally. Generally, Sneha Kalpana is prepared by using Agni as source of heating. However, Kasisadi Ghrita is an exception where the sunlight is used as source of heating. This unusual method of preparation looks attractive because of natural heat (sunlight) that is required in the preparation and the yield that may be obtained. The Sneha is heated with volatile drugs in Surya Paka for a specific time so that less heat allows them to leave their active principles in Sneha. The difference between Bhanupaka and Agnipaka is also an area of interest, on this formulation as far as its manufacturing is considered. Kasisadi Ghrita is a herbo-mineral formulation indicated for various skin diseases. Materials and Methods: Kasisadi Ghrita were prepared by classical method of Bhanupaka (KGB) and usual method of Agnipaka (KGA). Both KGB and KGA were analyzed as per the standard protocol. Discussion and Conclusion: Preparation of Kasisadi Ghrita by Agnipaka method is easy as it consumes less time. There were no pharmaceutical constraints in preparation of both samples. Tamra Paatra helps to retain more heat than other vessels during Bhanupaka. The results of the pharmaceutical and analytical study can be considered as the preliminary standards for the preparation of Kasisadi Ghrita
The Concept of Culture in Critical Mathematics Education
© Springer International Publishing AG, part of Springer Nature 2018. This is a post-peer-review, pre-copyedit version of a chapter published in The Philosophy of Mathematics Education Today. The final authenticated version is available online at: http://dx.doi.org/10.1007/978-3-319-77760-3A well-known critique in the research literature of critical mathematics education suggests that framing educational questions in cultural terms can encourage ethnic-cultural essentialism, obscure conflicts within cultures and promote an ethnographic or anthropological stance towards learners. Nevertheless, we believe that some of the obstacles to learning mathematics are cultural. ‘Stereotype threat’, for example, has a basis in culture. Consequently, the aims of critical mathematics education cannot be seriously pursued without including a cultural approach in educational research. We argue that an adequate conception of culture is available and should include normative/descriptive and material/ideal dyads as dialectical moments
First Spectroscopic Confirmations of z ~ 7.0 Lya Emitting Galaxies in the LAGER Survey
Narrowband imaging is a highly successful approach for finding large numbers
of high redshift Lya emitting galaxies (LAEs) up to z~6.6. However, at z>~7
there are as yet only 3 narrowband selected LAEs with spectroscopic
confirmations (two at z~6.9-7.0, one at z~7.3), which hinders extensive studies
on cosmic reionization and galaxy evolution at this key epoch. We have selected
23 candidate z~6.9 LAEs in COSMOS field with the large area narrowband survey
LAGER (Lyman-Alpha Galaxies at the End of Reionization). In this work we
present spectroscopic followup observations of 12 candidates using IMACS on
Magellan. For 9 of these, the observations are sufficiently deep to detect the
expected lines. Lya emission lines are identified in six sources (yielding a
success rate of 2/3), including 3 luminous LAEs with Lya luminosities of L(Lya)
~ 10^{43.5} erg/s, the highest among known spectroscopically confirmed galaxies
at >~7.0. This triples the sample size of spectroscopically confirmed
narrowband selected LAEs at z>~7, and confirms the bright end bump in the Lya
luminosity function we previously derived based on the photometric sample,
supporting a patchy reionization scenario. Two luminous LAEs appear physically
linked with projected distance of 1.1 pMpc and velocity difference of ~ 170
km/s. They likely sit in a common ionized bubble produced by themselves or with
close neighbors, which reduces the IGM attenuation of Lya. A tentative narrow
NV1240 line is seen in one source, hinting at activity of a central
massive black hole with metal rich line emitting gas.Comment: 6 pages, 3 figures, 2 tables, accepted by ApJ
Investigation of the Mechanical Properties of Glass Fiber – Chicken Feather Hybrid Composite
The production and/or worldwide consumption of chicken at an industrial or domestic level lead to a considerable quantity of chicken feather residue as a waste by-product. Chicken feathers have a possible application in preparing lightweight composites. The use of chicken feathers as a constituent to prepare hybrid composites leads to a solution for disposal of the feathers. In this study, chicken feathers were used as filler material to prepare hybrid composites. Different varieties of composites were prepared by a chicken feather hand-layup technique, and by varying the percentage weight of the chicken feathers. Specimens were prepared and tested according to ASTM standards. The 10 wt. % chicken feather-filled hybrid composites indicated the maximum tensile strength (193 MPa), flexural strength (148 MPa) and impact strength (3.65 Joules). Scanning Electron Microscopy (SEM) analysis was carried out to find the fracture and interfacial characteristics of the composites. The results indicated that, these composites can be used in domestic, automobile and structural applications which carry nominal loads
The distribution of satellites around massive galaxies at 1<z<3 in ZFOURGE/CANDELS: dependence on star formation activity
We study the statistical distribution of satellites around star-forming and
quiescent central galaxies at 1<z<3 using imaging from the FourStar Galaxy
Evolution Survey (ZFOURGE) and the Cosmic Assembly Near-IR Deep Extragalactic
Legacy Survey (CANDELS). The deep near-IR data select satellites down to
at z<3. The radial satellite distribution around centrals
is consistent with a projected NFW profile. Massive quiescent centrals,
, have 2 times the number of satellites compared
to star-forming centrals with a significance of 2.7 even after
accounting for differences in the centrals' stellar-mass distributions. We find
no statistical difference in the satellite distributions of intermediate-mass
quiescent and star-forming centrals, . Comparing
to the Guo2011 semi-analytic model, the excess number of satellites indicates
that quiescent centrals have halo masses 0.3 dex larger than star-forming
centrals, even when the stellar-mass distributions are fixed. We use a simple
toy model that relates halo mass and quenching, which roughly reproduces the
observed quenched fractions and the differences in halo mass between
star-forming and quenched galaxies only if galaxies have a quenching
probability that increases with halo mass from 0 for
11 to 1 for 13.5. A single
halo-mass quenching threshold is unable to reproduce the quiescent fraction and
satellite distribution of centrals. Therefore, while halo quenching may be an
important mechanism, it is unlikely to be the only factor driving quenching. It
remains unclear why a high fraction of centrals remain star-forming even in
relatively massive halos.Comment: 19 pages, 17 figures, accepted by ApJ. Information on ZFOURGE can be
found at http://zfourge.tamu.ed
A aprendizagem matemática em uma posição de fronteira: foregrounds e intencionalidade de estudantes de uma favela brasileira
Glassy State Lead Tellurite Nanobelts: Synthesis and Properties
The lead tellurite nanobelts have been first synthesized in the composite molten salts (KNO3/LiNO3) method, which is cost-effective, one-step, easy to control, and performed at low-temperature and in ambient atmosphere. Scanning electron microscopy, X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectrum, energy dispersive X-ray spectroscopy and FT-IR spectrum are used to characterize the structure, morphology, and composition of the samples. The results show that the as-synthesized products are amorphous and glassy nanobelts with widths of 200–300 nm and lengths up to tens of microns and the atomic ratio of Pb:Te:O is close to 1:1.5:4. Thermo-gravimetric analysis (TGA) and differential scanning calorimetry (DSC) and investigations of the corresponding structure and morphology change confirm that the nanobelts have low glass transition temperature and thermal stability. Optical diffuse reflectance spectrum indicates that the lead tellurite nanobelts have two optical gaps at ca. 3.72 eV and 4.12 eV. Photoluminescence (PL) spectrum and fluorescence imaging of the products exhibit a blue emission (round 480 nm)
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