3,278 research outputs found
A New Imperative for Detracking Schools. A Book Review of \u3cem\u3eOn the Same Track:How Schools Can Join the Twenty-First-Century Struggle Against Resegregation\u3c/em\u3e
In her 2014 book, On the Same Track: How Schools Can Join the Twenty-First-Century Struggle Against Resegregation, Burris builds upon the compelling case made for detracking put forth by Oakes and others in the 1970s and â80s. Today, decades after the pioneers in detracking schools, Burris revisits the tracking practices still prevalent in Americaâs public schools through the lenses of those who are in the racial or ethnic minority and who are poor and at a time when school accountability often drives school practice and school choice to additional layers of sorting
A kilonova associated with GRB 070809
For on-axis typical short gamma-ray bursts (sGRBs), the forward shock
emission is usually so bright that renders the identification of kilonovae
(also known as macronovae) in the early afterglow ( d) phase rather
challenging. This is why previously no thermal-like kilonova component has been
identified at such early time except in the off-axis dim GRB 170817A associated
with GW170817. Here we report the identification of an unusual optical
radiation component in GRB 070809 at d, thanks plausibly to the
very-weak/subdominant forward shock emission. The optical emission with a very
red spectrum is well in excess of the extrapolation of the X-ray emission that
is distinguished by an unusually hard spectrum, which is at odds with the
forward shock afterglow prediction but can be naturally interpreted as a
kilonova. Our finding supports the speculation that kilonovae are ubiquitous ,
and demonstrates the possibility of revealing the neutron star merger origin
with the early afterglow data of some typical sGRBs that take place well beyond
the sensitive radius of the advanced gravitational wave detectors and hence the
opportunity of organizing dedicated follow-up observations for events of
interest.Comment: 20 pages, 5 figures, published in Nature Astronom
Road transport energy consumption in the G7 and BRICS: 1973â2010
Road transport will account for a large share of developing countriesâ future energy demand. This paper reviews the trends in road transport energy consumption in 12 countries (Group of Seven (G7) and BRICS) over the period 1973â2010. We report several stylised facts: road transport energy use and its share in total energy use have been rising; there were large differences in road transport energy use per capita across countries, resulting from differences in country size, resource endowments, fuel prices and other factors; oil accounts for around 95% of road transport energy in the selected countries except Brazil; oil will likely be the dominant road transport energy source in most countries for some years to come but not in the long run; and the use of alternative road transport energy sources is increasing.We are thankful for financial support from the âStrategic Priority Research Programâ of the Chinese Academy of Sciences (No. XDA05150600), National Natural Science
Foundation of China (No. 71322306, 71273027 and 71020107026) and Program for New Century Excellent Talents in University of Ministry of Education of China
(No. NCET-13-0040)
Automatic arc discharge-induced helical long period fiber gratings and its sensing applications
We experimentally demonstrate an automatic arc discharge technology for inscribing high-quality helically twisted long period fiber gratings (H-LPFGs) with greatly improved inscription efficiency for single mode fibers. The proposed technology has been developed by implementing an embedded program in a commercial fusion splicer, which employs an ultraprecision motorized translation stage while the tensioning mass required by conventional inscribing technology is eliminated. More significantly, the arc-induced H-LPFGs have been reported to have potential usage as sensors in temperature, refractive index, twist stress, and strain
Using T-cell repertoire profiles as predictor in a primary mucosal melanoma
Dear Editor, Primary mucosal melanoma is a rare subtype of melanoma that carries poor prognosis. Traditional treatment options of mucosal melanoma are surgery, radiation, and chemotherapy; but the overall survival remains low.1 Cytotoxic Tâlymphocyte associated protein 4 (CLTAâ4) and programmed cell death protein 1 (PDâ1), both inhibitory immune checkpoints commonly seen on activated T cells, have been found to be promising targets for treatment of advanced cancers.2 However, the efficacy and response to immunotherapy in mucosal melanoma remains unknown. Herein, we report a case involving a patient, who was a 70âyearâold male and referred to Taipei Medical University Hospital with confirmed diagnosis of mucosa melanoma over hard plate of mouth. The patient was admitted and subjected to antiâPDâ1 immunotherapy (pembrolizumab 200 mg every 3 weeks) (Figure 1A). Serial imaging of primary malignant melanoma of the hard palate showed that the tumor size gradually decreased after treatment with pembrolizumab, suggesting partial response/stable disease secondary to continuous immunotherapy (Figure 1B). However, after seventh cycle of treatment, magnetic resonance imaging (MRI) revealed enlarged previous known metastatic lesions and new tumor nodules in brain (Figure 1B). The patient received stereotactic radiation therapy before treatment cycle 14 (Figure 1A). Although the primary metastatic brain lesions were smaller and stationary after radiotherapy, the following brain MRI displayed several hyperdensity masses in the right frontal lobe with perifocal edema and mild mass effect (Figure 1B). Subsequently, patient suffered from infection and respiratory distress and died 2 months after 17th cycle of pembrolizumab therapy
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