Low noise charge injection in the CCD22

The inclusion of a charge injection structure on a charge coupled device (CCD) allows for the mitigation of charge transfer loss which can be caused by radiation induced charge trapping defects. Any traps present in the pixels of the CCD are filled by the injected charge as it is swept through the device and consequently, the charge transfer efficiency is improved in subsequently acquired images. To date, a number of different types of CCD have been manufactured featuring a variety of charge injection techniques. The e2v Technologies CCD22, used in the EPIC MOS focal plane instruments of XMM-Newton, is one such device and is the subject of this paper. A detailed understanding of charge injection operation and the use of charge injection to mitigate charge transfer losses resulting from radiation damage to CCDs will benefit a number of space projects planned for the future, including the ESA GAIA and X-ray Evolving Universe Spectrometry (XEUS) missions.The charge injection structure and mode of operation of the CCD22 are presented, followed by a detailed analysis of the uniformity and repeatability of the charge injection amplitude across the columns of the device. The effects of proton irradiation on the charge injection characteristics are also presented, in particular the effect of radiation induced bright pixels on the injected charge level

Validation of Omron™ Pedometers Using MTI Accelerometers for Use with Children

International Journal of Exercise Science 6(2) : 106-113, 2013. The MTI accelerometer is highly regarded as a reliable means to measure physical activity in children (Trost et. al., 1998); however, it is not always a practical instrument to use. Pedometers offer an alternative method of activity measurement and are often more practical. PURPOSE: To validate Omron™ pedometer (steps/day) against MTI accelerometer (counts /day and moderate to vigorous physical activity (MVPA) min/day) for children. METHODS: 190 children (88 males, 102 females, 8.7±2.1 yrs, 76.9±27.5 BMI %tile) wore an MTI accelerometer and Omron™ pedometer attached to the same belt for 3.9±2.2 days. MVPA was defined as movement ≥4 METs (Troiano et al., 2008). A Pearson correlation coefficient was used to determine validity coefficients between Omron™ steps/day and MTI accelerometer MVPA min/day and counts/day. A stepwise regression was used to predict MVPA using Omron steps/day, sex, and age with 488 days of data. Cross-validation and paired t-tests were used to determine differences from predicted MVPA and actual MVPA. RESULTS: The correlations between Omron™ steps/day with both MTI counts/day and MTI MVPA min/day were r=0.79, p\u3c0.05 and r=0.74, p\u3c0.05 respectively. The model generated from the multiple regression equation accounted for 67% of the variance (r2 = 0.6689, SEE = 24.5) in MVPA, MVPA = 67.99 + 0.0068(steps/day) + -7.531(age in years) + 5.559(sex). CONCLUSION: Our validation correlations between the Omron™ pedometer and MTI accelerometer were acceptable The results indicate that the Omron pedometer can be used to estimate MVPA minutes and could serve as a useful alternative to accelerometry for those with limited resources or in practical situations

Reef response to sea-level and environmental changes during the last deglaciation: Integrated Ocean Drilling Program Expedition 310, Tahiti Sea Level

The last deglaciation is characterized by a rapid sea-level rise and coeval abrupt environmental changes. The Barbados coral reef record suggests that this period has been punctuated by two brief intervals of accelerated melting (meltwater pulses, MWP), occurring at 14.08-13.61 ka and 11.4-11.1 ka (calendar years before present), that are superimposed on a smooth and continuous rise of sea level. Although their timing, magnitude, and even existence have been debated, those catastrophic sea-level rises are thought to have induced distinct reef drowning events. The reef response to sea-level and environmental changes during the last deglacial sea-level rise at Tahiti is reconstructed based on a chronological, sedimentological, and paleobiological study of cores drilled through the relict reef features on the modern forereef slopes during the Integrated Ocean Drilling Program Expedition 310, complemented by results on previous cores drilled through the Papeete reef. Reefs accreted continuously between 16 and 10 ka, mostly through aggradational processes, at growth rates averaging 10 mm yr-1. No cessation of reef growth, even temporary, has been evidenced during this period at Tahiti. Changes in the composition of coralgal assemblages coincide with abrupt variations in reef growth rates and characterize the response of the upward-growing reef pile to nonmonotonous sea-level rise and coeval environmental changes. The sea-level jump during MWP 1A, 16 ± 2 m of magnitude in ~350 yr, induced the retrogradation of shallow-water coral assemblages, gradual deepening, and incipient reef drowning. The Tahiti reef record does not support the occurrence of an abrupt reef drowning event coinciding with a sea-level pulse of ~15 m, and implies an apparent rise of 40 mm yr-1 during the time interval corresponding to MWP 1B at Barbados. © 2012 Geological Society of America

Physicochemical properties and sensory attributes of local snacks fortified with powdered fish processing by-products and an underutilised fish species

Fish processing by-products and small pelagic fish could provide minerals and protein in diets of vulnerable populations as these could be more affordable than seafood. The study objectives were to determine the proximate nutrient content of tuna processing by-products and burrito fish and also assess the acceptability of fish powder-fortified local carbohydrate snacks. Tuna trimmings, gills, frames and burrito were dried at 55oC for eight hours to moisture levels of 4.8% (trimmings), 8.9% (frames), 6.8% (gills) and 6.9% (burrito). The products were milled and incorporated at varying levels into four local snacks namely: mpotompoto, yakayake, abolo and yam balls. Proximate nutrient levels of both fortified and non-fortified snacks were determined by Official Methods of Analysis (AOAC). Protein contents of mpotompoto-fortified fish products ranged from 3.75% to 8.5%. Ash also ranged from 1.12% to 5.54%. The control contained 1.17%. Acceptability tests were conducted on the fortified snacks using a 5-point hedonic scale. On the whole, fortified products showed significantly higher levels of protein and ash over the non-fortified snacks. Acceptance of the snacks by pupils (11-12) years was high enough to warrant incorporation of the fish powders into a school lunch menu

Cross-school ‘close-to-practice’ action research, system leadership and local civic partnership re-engineering an inner-city learning community

This article presents two sequential case reports of how 60 schools in the London Borough of Camden used action research in three phases of development of their local school system reform, from a traditional council-led, top-down model of centrally based professional development and monitoring of schools, to one that is schools-led and ‘bottom-up’ in nature, but still in close partnership with its local council and community. The article uses a sociocultural lens through which to view this journey of self-reform, tracking change through three evolutions of the sociocultural model as professional learning becomes situated in classrooms and between schools in Camden, as motivations to develop and change become increasingly intrinsic and less driven by fear of failure or the consequences of failure. Of critical importance is the feedback-rich context created by adoption of enquiry- and coaching-based learning models at classroom, organizational and system levels. This both fuels and is fuelled by the strategic collaboration of head teachers and by system leadership also provided by middle leaders, whose increased cross-school agency builds improvement capacity and collaborative capital. The article does not report on the action research alone: unlike many accounts of action research for change, this account provides a narrative backdrop in which to locate both scientific and system developments. This is provided through three short vignettes that place the changes reported in a societal, political and community context, without whose energetic actors (in the form of local political and community leaders and school governors) the local ‘civic governance’ so strongly behind these reforms, would not have existed

Scattering of massive Dirac particles by a Kink-like potential

The scattering state of spin ½ particles with Kink-like potential is studied under the massive Dirac equation. We obtain the scattering states in terms of the hypergeometric functions and calculate the reflection coefficient (R) and transmission coefficient (T)