1,020 research outputs found
A Survey of Learning Styles of Engineering Students
This study examined the learning styles of engineering students using the Index of Learning Styles (ILS) developed by Soloman and Felder (Soloman & Felder, 2002), the Cognitive Styles Analysis (CSA) developed by Riding (Riding, 1991), and the Learning Style Inventory (LSI) developed by Kolb (Kolb, 1993). Thirty-five graduate and thirty-six undergraduate engineering students took each of the assessments. There was a strong preference for the visual category on the ILS, but an even split for the imagery/verbal dimension on the CSA. Scores were also evenly split on the active/reflective and sequential/global dimensions on the ILS. Another strong preference was seen for the analytic category on the CSA. On the LSI, most students' scores indicated a preference for the convergent category and no student scores were in the divergent category. An overview of each of the instruments as well as a summary of student learning needs for each of the dimensions is presented.Yeshttps://us.sagepub.com/en-us/nam/manuscript-submission-guideline
Late Miocene Mediterranean desiccation: topography and significance of the 'Salinity Crisis' erosion surface on-land in southeast Spain: Reply
We welcome this opportunity to amplify the results
of our studies of the Late Miocene Messinian
sequence in the Sorbas Basin of southeast Spain.
The Salinity Crisis concept has captured geological
imagination and found its way into textbooks, but
scrutiny reveals its details to be disturbingly elusive.
Our approach has been to read the history of this
important episode in Neogene history in well-exposed
on-land sections at Sorbas, AlmerĂa, near the western
end of the Mediterranean. The Salinity Crisis concept,
as it was first proposed (HsĂŒ et al., 1973, 1977) and
has largely survived (Cita, 1991), is of deep-desiccation
and reflooding of the Mediterranean near the
close of the Miocene. Marine downdraw resulted in
marginal erosion; evaporites accumulated in depressions;
and final marine reflooding completed the
cycle. Our rationale is that if these principal tenets
of the concept are correct, then one or more of their
effects should be recorded throughout the region, both
on the deep Mediterranean floor and in marginal
basins that were contemporaneously connected to
the Mediterranean, including the Sorbas Basin. This
emphasis on the widespread effects of the Salinity
Crisis does not exclude the possibility that they
were overprinted by local conditions, which probably
differed considerably over a region as extensive and
diverse as the Mediterranean basins. Indeed, we have
interpreted the evaporites of the Sorbas Basin to be
local products of basin barring, related to the Salinity
Crisis but not coeval with deep Mediterranean evaporites.
At the same time, we have taken the view that the
regional result of the Salinity Crisis in all marginal
basins should be an erosion surface on the scale of the
massive sea-level fall implied by the concept. It is our
recognition of this erosion surface in the Sorbas Basin
that has drawn most criticism from Fortuin et al.
(2000). Here we provide further details of critical
localities so that our observations can be accurately
assessed
Supporting school improvement: The development of a scale for assessing pupils' emotional and behavioural development
Available online via the Taylor & Francis Group site by subscription
Diamicton from the Vale of Pickering and Tabular Hills, north-east Yorkshire: evidence for a Middle Pleistocene (MIS 8) glaciation?
Diamicton deposits (up to 6.90 m thick) in the Vale of Pickering and the Tabular Hills (North York Moors) have been confirmed by cored boreholes. The diamicton is interpreted as glacial till with a matrix consisting predominantly of grey-brown, yellow-brown and dark grey, stiff to very stiff clay and sandy clay with occasional thin beds of laminated sand and clay. Sub-rounded to sub-angular erratic clasts were sourced predominantly from local Upper Jurassic Corallian Group bedrock exposed in the southern part of the North York Moors. Clasts include well-rounded, pebbles of Jurassic sandstone, mudstone and sparse Jurassic coal derived from outcrops on the North York Moors. Fragments of underlying Upper Jurassic mudstone bedrock form the predominant clasts in the lower part of the till. The paucity of exotic clasts and a local derivation suggests a relatively small glacier â perhaps a temperate-plateau ice-field, was established on the Tabular Hills. The glacier subsequently advanced southwards to the Vale of Pickering depositing locally derived subglacial traction till at the base, passing up to lodgement till. Local preservation of the degraded till outcrops in the Vale of Pickering, the overconsolidated nature of the clay till matrix, striated pebbles and the presence of sub-rounded pebbles suggests deposition during a glacial cold stage post-MIS 12 (Anglian) and pre-MIS 2 (Devensian). A tentative Middle Pleistocene MIS8 age is proposed, possibly coeval, but not coincident, with the Basement Till (Bridlington Member) of the Holderness coast and the Wragby Till of central and eastern England
Pleistocene till provenance in east Yorkshire:Reconstructing ice flow of the British North Sea Lobe
The ice flow path and dynamic behaviour of the British-Irish Ice Sheet has been subject to renewed interest and controversy in recent years. Early studies in eastern England argued for interaction with Fennoscandian ice onshore in Britain, instigating re-examination of the sedimentology and provenance of many Pleistocene till successions. These studies instead supported an exclusively British provenance, and are used to predict southward advance of a broadly coast-parallel North Sea Lobe. Quantitative lithological and palynological analysis of the Pleistocene till succession in Holderness, East Yorkshire, however, remains to be carried out. We examined the lithologically diverse Skipsea Till in order to reconstruct ice flow pathways to the Holderness coast during the Pleistocene, thereby constraining which areas of substrate were subglacially eroded and entrained prior to deposition. The till yields a diverse range of soft, low-durability and uniquely British allochthonous material, including Permian Magnesian Limestone, Carboniferous limestone and coal, and Carboniferous pollen and spore assemblages that would be unlikely to survive polyphase reworking. Ice extended southwards through southern Scotland, incorporating material in north-east England, north-east Yorkshire and the western margin of the North Sea Basin (NSB), supporting a recurrent ice flow pathway for the eastern margin of the British-Irish Ice Sheet during the Mid to Late Pleistocene
The Paleocene of Antarctica: dinoflagellate cyst biostratigraphy, chronostratigraphy and implications for the palaeo-Pacific margin of Gondwana
The Paleocene (66â56 Ma) was a critical time interval for understanding recovery from mass extinction in high palaeolatitudes when global climate was warmer than today. A unique sedimentary succession from Seymour Island (Antarctic Peninsula) provides key reference material from this important phase of the early Cenozoic. Dinoflagellate cyst data from a 376 m thick stratigraphical section, including the CretaceousâPaleogene boundary, is correlated with biozones from New Zealand, the East Tasman Plateau and southeastern Australia. A detailed age model is suggested for the LĂłpez de Bertodano (LDBF) and Sobral (SF) formations based on dinoflagellate cyst biostratigraphy and U-Pb dating of zircons, supported by correlated magnetostratigraphy and strontium isotope values from macrofossils. The top of the LDBF is confirmed as latest Maastrichtian to earliest Danian (~ 66.2â65.65 Ma) in age. The overlying SF is mostly Danian in age, with an inferred hiatus near the top overlain by sediments dated as? late Thanetian. Rare Apectodinium homomorphum first appear in the uppermost SF; the first in situ record from Antarctica. The distribution of marine and terrestrial fossils from uppermost Cretaceous to Eocene sediments in Patagonia, Antarctica, New Zealand and Australia required both sea and land connections between these fragments of Gondwana. Fossil evidence and reconstructions of Antarctic palaeogeography and palaeotopography reveals evidence for persistent embayments in the proto-Weddell and Ross Sea regions at this time. We conclude that a coastal dispersal route along the palaeo-Pacific margin of Gondwana could explain the fossil distribution without requiring a transAntarctic strait or closely spaced archipelago. A region in the West to East Antarctic boundary zone, elevated until the early Paleogene, perhaps acted as a site for high elevation ice caps. This supports fossil, geochemical and sedimentological evidence for cold climate intervals and significant sea level falls during the Maastrichtian and Paleocene
Why business angels reject investment opportunities: Is it personal?
A major focus of research on business angels has examined their decision-making processes and investment criteria. As business angels reject most of the opportunities that they receive, this article explores the reasons informing such decisions. In view of angel heterogeneity, investment opportunities might be expected to be rejected for differing reasons. Two sources of data are used to examine this issue. Face-to-face interviews with 30 business angels in Scotland and Northern Ireland provided information on typical âdeal killersâ. This was complemented by an Internet survey of United Kingdom that attracted responses from 238 UK business angels. The findings confirm that the main reason for rejection relates to the entrepreneur/management team. However, angel characteristics do not explain the number of reasons given for opportunity rejection nor do they predict the reasons for rejecting investment opportunities. This could be related to the increasing trend for business angels to join organised groups which, in turn, leads to the development of a shared repertoire of investment approaches. We suggest the concept of âcommunities-of-practiceâ as an explanation for this finding
Impaired natural killer cell phenotype and function in idiopathic and heritable pulmonary arterial hypertension
BACKGROUND: Beyond their role as innate immune effectors, natural killer (NK) cells are emerging as important regulators of angiogenesis and vascular remodeling. Pulmonary arterial hypertension (PAH) is characterized by severe pulmonary vascular remodeling and has long been associated with immune dysfunction. Despite this association, a role for NK cells in disease pathology has not yet been described.
METHODS AND RESULTS: Analysis of whole blood lymphocytes and isolated NK cells from PAH patients revealed an expansion of the functionally defective CD56(-)/CD16(+) NK subset that was not observed in patients with chronic thromboembolic pulmonary hypertension. NK cells from PAH patients also displayed decreased levels of the activating receptor NKp46 and the killer immunoglobulin-like receptors 2DL1/S1 and 3DL1, reduced secretion of the cytokine macrophage inflammatory protein-1ÎČ, and a significant impairment in cytolytic function associated with decreased killer immunoglobulin-like receptor 3DL1 expression. Genotyping patients (n=222) and controls (n=191) for killer immunoglobulin-like receptor gene polymorphisms did not explain these observations. Rather, we show that NK cells from PAH patients exhibit increased responsiveness to transforming growth factor-ÎČ, which specifically downregulates disease-associated killer immunoglobulin-like receptors. NK cell number and cytotoxicity were similarly decreased in the monocrotaline rat and chronic hypoxia mouse models of PAH, accompanied by reduced production of interferon-Îł in NK cells from hypoxic mice. NK cells from PAH patients also produced elevated quantities of matrix metalloproteinase 9, consistent with a capacity to influence vascular remodeling.
CONCLUSIONS: Our work is the first to identify an impairment of NK cells in PAH and suggests a novel and substantive role for innate immunity in the pathobiology of this disease
Do big athletes have big hearts? Impact of extreme anthropometry upon cardiac hypertrophy in professional male athletes.
AIM: Differentiating physiological cardiac hypertrophy from pathology is challenging when the athlete presents with extreme anthropometry. While upper normal limits exist for maximal left ventricular (LV) wall thickness (14 mm) and LV internal diameter in diastole (LVIDd, 65 mm), it is unknown if these limits are applicable to athletes with a body surface area (BSA) >2.3 m(2). PURPOSE: To investigate cardiac structure in professional male athletes with a BSA>2.3 m(2), and to assess the validity of established upper normal limits for physiological cardiac hypertrophy. METHODS: 836 asymptomatic athletes without a family history of sudden death underwent ECG and echocardiographic screening. Athletes were grouped according to BSA (Group 1, BSA>2.3 m(2), n=100; Group 2, 2-2.29 m(2), n=244; Group 3, 13 mm, but in combination with an abnormal ECG suspicious of an inherited cardiac disease. CONCLUSION: Regardless of extreme anthropometry, established upper limits for physiological cardiac hypertrophy of 14 mm for maximal wall thickness and 65 mm for LVIDd are clinically appropriate for all athletes. However, the abnormal ECG is key to diagnosis and guides follow-up, particularly when cardiac dimensions are within accepted limits
Earliest Triassic microbialites in the South China Block and other areas; controls on their growth and distribution
Earliest Triassic microbialites (ETMs) and inorganic carbonate crystal fans formed after the end-Permian mass extinction (ca. 251.4 Ma) within the basal Triassic Hindeodus parvus conodont zone. ETMs are distinguished from rarer, and more regional, subsequent Triassic microbialites. Large differences in ETMs between northern and southern areas of the South China block suggest geographic provinces, and ETMs are most abundant throughout the equatorial Tethys Ocean with further geographic variation. ETMs occur in shallow-marine shelves in a superanoxic stratified ocean and form the only widespread Phanerozoic microbialites with structures similar to those of the Cambro-Ordovician, and briefly after the latest Ordovician, Late Silurian and Late Devonian extinctions. ETMs disappeared long before the mid-Triassic biotic recovery, but it is not clear why, if they are interpreted as disaster taxa. In general, ETM occurrence suggests that microbially mediated calcification occurred where upwelled carbonate-rich anoxic waters mixed with warm aerated surface waters, forming regional dysoxia, so that extreme carbonate supersaturation and dysoxic conditions were both required for their growth. Long-term oceanic and atmospheric changes may have contributed to a trigger for ETM formation. In equatorial western Pangea, the earliest microbialites are late Early Triassic, but it is possible that ETMs could exist in western Pangea, if well-preserved earliest Triassic facies are discovered in future work
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