Gravity, geoid and the oceanic lithosphere

Plate tectonics and its contribution to progress in studies of the Earth's gravitational field is discussed. In acquisition, the development of forced feedback accelerometers, satellite navigation, and satellite radar altimetry significantly improved the accuracy and coverage of gravity data over the oceans. In interpretation, gravity and geoid anomalies are used to determine information on the thermal and mechanical properties of the oceanic lithosphere and the forces that drive plate motions

Striving against invalidity in qualitative research: Discussing a reflective framework

The aim of this paper is to discuss a reflective validation framework related with the study of teaching approaches, teaching styles or teaching orientations of university academics. In the recent years, and particularly since the eighties, there have been a growing number of investigations linking teaching conceptions with teaching practices. The majority of investigations dealing with university teachers’ conceptions and practices draw their conclusions based on indirect observation, since data gathering involves mainly semi-structured interviews or the application of questionnaires and inventories. Therefore ‘only-half-the-story’ has been reported. The presented validation framework has a five-part three-stage structure and was built upon earlier work (Selvaruby, O’Sullivan, & Watts, 2007). In this model validity is conceptualized as an ‘iterative-interactive-process’, therefore integrating a set of specific strategies envisaging the maximization of scientific quality. The application of the model is illustrated by using it for the discussion of a longitudinal study involving the investigation of the relationship between questioning practices and Trigwell and co-workers’ concept of preferential teaching approaches (Trigwell, Prosser & Taylor, 1994). Field work of this naturalistic-interpretative research was conducted during two academic years (2009/2010 and 2010/2011) and implied close collaboration with a group of four university teachers lecturing biology to undergraduates.This work was financed by Fundação para a Ciência e a Tecnologia (SFRH/BD/44611/2008) and by Fundos FEDER através do Programa Operacional Fatores de Competitividade – COMPETE e por Fundos Nacionais através da FCT (PTDC/CPE-CED/117516/2010)

Novelty and Collective Attention

The subject of collective attention is central to an information age where millions of people are inundated with daily messages. It is thus of interest to understand how attention to novel items propagates and eventually fades among large populations. We have analyzed the dynamics of collective attention among one million users of an interactive website -- \texttt{digg.com} -- devoted to thousands of novel news stories. The observations can be described by a dynamical model characterized by a single novelty factor. Our measurements indicate that novelty within groups decays with a stretched-exponential law, suggesting the existence of a natural time scale over which attention fades

TOBACCO'S IMPORTANT ROLE IN THE ECONOMY OF SOUTHSIDE VIRGINIA

Community/Rural/Urban Development, Crop Production/Industries,

Analysis of variability in the burst oscillations of the accreting millisecond pulsar XTE J1814-338

The accreting millisecond pulsar XTE J1814-338 exhibits oscillations at the known spin frequency during Type I X-ray bursts. The properties of the burst oscillations reflect the nature of the thermal asymmetry on the stellar surface. We present an analysis of the variability of the burst oscillations of this source, focusing on three characteristics: fractional amplitude, harmonic content and frequency. Fractional amplitude and harmonic content constrain the size, shape and position of the emitting region, whilst variations in frequency indicate motion of the emitting region on the neutron star surface. We examine both long-term variability over the course of the outburst, and short-term variability during the bursts. For most of the bursts, fractional amplitude is consistent with that of the accretion pulsations, implying a low degree of fuel spread. There is however a population of bursts whose fractional amplitudes are substantially lower, implying a higher degree of fuel spread, possibly forced by the explosive burning front of a precursor burst. For the first harmonic, substantial differences between the burst and accretion pulsations suggest that hotspot geometry is not the only mechanism giving rise to harmonic content in the latter. Fractional amplitude variability during the bursts is low; we cannot rule out the hypothesis that the fractional amplitude remains constant for bursts that do not exhibit photospheric radius expansion (PRE). There are no significant variations in frequency in any of the bursts except for the one burst that exhibits PRE. This burst exhibits a highly significant but small ($\approx 0.1$Hz) drop in frequency in the burst rise. The timescale of the frequency shift is slower than simple burning layer expansion models predict, suggesting that other mechanisms may be at work.Comment: 20 pages, 20 figures, accepted for publication in ApJ. Uses emulateapj.cl

Whitstable maritime trail

Notes for tour guides taking a tour of Whitstable's maritime heritage

Optimized bolted joint

A method is disclosed for joining segments of the skin of an aircraft. The ends of the skin are positioned in close proximity or abutt each other. The skin is of constant thickness throughout the joint and is sandwiched between splice plates, which taper in thickness from the last to the first bolt rows in order to reduce the stiffness of the splice plate and thereby reduce the load transfer at the location where bypass loads are the highest

Virginia peregrine falcon monitoring and management program: Year 2018 report

The peregrine falcon (Falco peregrinus) was believed to be extirpated as a breeding species in Virginia by the early 1960s. An aggressive restoration program was initiated in 1978 that included the release of 115 captive-reared birds on the Coastal Plain (1978-1985) and 127 birds in the mountains (1985-1993). This program resulted in the first breeding of the modern era in 1982. Since this time, the population has proceeded through a rapid establishment phase followed by a consolidation phase. However, more than 95% of all breeding activity over the past 30 years has occurred on the Coastal Plain with very limited breeding within the historic mountain range. Since 2000 a dedicated translocation program has moved more than 250 birds from eyries on the coast to hack sites in the mountains in an effort to restore the mountain breeding population. Restoration of the breeding population in the mountains continues to be a management priority for the state. In 2018, Virginia supported a known falcon population of 32 breeding pairs including 28 within the Coastal Plain, 1 in the Piedmont and 3 in the mountains. This is the highest population ever recorded in the state and represents the sixth consecutive year that the population has exceeded 25 breeding pairs. A new breeding territory was documented on a crane within the Norfolk Naval Shipyard. Long-time territories including the Norris Bridge and the Highrise Bridge (I-64) were vacant in 2018. A single adult male was observed on the I-295 bridge across the James River. 2018 was a mixed breeding year with a relatively low hatching rate (67%, 45 of 67 eggs hatched) and no losses before banding. Three young were known to be lost after fledging. Of 17 clutches that were followed completely from laying to fledging, 36 of 57 (63%) eggs hatched and 36 of 36 (100%) young survived to banding age. The reproductive rate (1.25 young/occupied territory) was considerably lower than in recent years. Efforts continued in 2018 to identify breeding adults via field-readable bands to better understand dispersal and demography throughout the mid-Atlantic region. The banding status of 46 (73%) of the 64 adult peregrines known within the breeding population was determined. Thirteen (28%) of the 46 birds were unbanded. The alpha-numerics were read for 29 adults and of these the USGS bands have been recorded for 27. Of the banded birds where state of origin could be determined, 22 were from VA, 3 were from NJ, 4 were from MD and 1 was from PA. The natal territories were determined for 27 adults. Birds ranged in age from 3 to 18 years old. Bands for 9 additional falcons were read and reported over the past year. Six of these birds (1 male, 5 females) originated in Virginia and were found breeding in other states (Table 5). This included 4 birds in Pennsylvania and 2 birds in New Jersey. A 10-year male banded on Watts Island was resighted in Talbot County, MD on 14 December, 2017. A hatch-year male banded in Reston Town Center was resighted on 27 June, 2018 in Loudon County, VA. A 13-year male banded on Benjamin Harrison Bridge and later hacked on Little Stony Man within Shenandoah National Park was photographed at Dyke Marsh in Alexandria, VA on 4 January, 2019