496 research outputs found
Suspended particulate matter in the Chesapeake Bay entrance and adjacent shelf waters
Approximately 400 samples were collected from the mouth of the Chesapeake Bay for various analyses, including 138 for suspended solids. Characteristics of suspended solids that were analyzed included: total suspended matter; total suspended inorganics, total suspended organics; percent organics; particle size distribution; and presence or absence of 11 of the most prominent particle types
Practicing mentorship: Graduate-student supervision of undergraduate research assistants
Many research universities rely on graduate students to supervise undergraduate research assistants (RAs) who collect data and handle research logistics. This experience can be mutually beneficial, as RAs receive hands-on learning, and graduate students practice mentorship in preparation for assuming a faculty role. However, assistantships must be intentionally designed to meet educational (not just practical) goals. What training and support do graduate students receive to take on this mentorship role? In two surveys, RAs reported on their satisfaction, educational benefit, and desired changes; while graduate students reported on their goals, challenges, and the support they receive
Electronic states and nature of bonding in the molecule YC by all electron ab initio multiconfiguration self-consistent-field calculations and mass spectrometric equilibrium experiments
New early Eocene tapiromorph perissodactyls from the Ghazij Formation of Pakistan, with implications for mammalian biochronology in Asia
Early Eocene mammals from Indo-Pakistan have only recently come under study. Here we describe the first tapiromorph perissodactyls from the subcontinent. Gandheralophus minor n. gen. and n. sp. and G. robustus n. sp. are two species of Isectolophidae differing in size and in reduction of the anterior dentition. Gandheralophus is probably derived from a primitive isectolophid such as Orientolophus hengdongensis from the earliest Eocene of China, and may be part of a South Asian lineage that also contains Karagalax from the middle Eocene of Pakistan. Two specimens are referred to a new, unnamed species of Lophialetidae. Finally, a highly diagnostic M3 and a molar fragment are described as the new eomoropid chalicothere Litolophus ghazijensis sp. nov. The perissodactyls described here, in contrast to most other mammalian groups published from the early Eocene of Indo-Pakistan, are most closely related to forms known from East and Central Asia. Tapiromorpha are diverse and biochronologically important in the Eocene there and our results allow the first biochronological correlation between early Eocene mammal faunas in Indo-Pakistan and the rest of Asia. We suggest that the upper Ghazij Formation of Pakistan is best correlated with the middle or late part of the Bumbanian Asian Land-Mammal Age, while the Kuldana and Subathu Formations of Pakistan and India are best correlated with the Arshantan Asian Land-Mammal Age
New Protocetid Whale from the Middle Eocene of Pakistan: Birth on Land, Precocial Development, and Sexual Dimorphism
BACKGROUND: Protocetidae are middle Eocene (49-37 Ma) archaeocete predators ancestral to later whales. They are found in marine sedimentary rocks, but retain four legs and were not yet fully aquatic. Protocetids have been interpreted as amphibious, feeding in the sea but returning to land to rest. METHODOLOGY/PRINCIPAL FINDINGS: Two adult skeletons of a new 2.6 meter long protocetid, Maiacetus inuus, are described from the early middle Eocene Habib Rahi Formation of Pakistan. M. inuus differs from contemporary archaic whales in having a fused mandibular symphysis, distinctive astragalus bones in the ankle, and a less hind-limb dominated postcranial skeleton. One adult skeleton is female and bears the skull and partial skeleton of a single large near-term fetus. The fetal skeleton is positioned for head-first delivery, which typifies land mammals but not extant whales, evidence that birth took place on land. The fetal skeleton has permanent first molars well mineralized, which indicates precocial development at birth. Precocial development, with attendant size and mobility, were as critical for survival of a neonate at the land-sea interface in the Eocene as they are today. The second adult skeleton is the most complete known for a protocetid. The vertebral column, preserved in articulation, has 7 cervicals, 13 thoracics, 6 lumbars, 4 sacrals, and 21 caudals. All four limbs are preserved with hands and feet. This adult is 12% larger in linear dimensions than the female skeleton, on average, has canine teeth that are 20% larger, and is interpreted as male. Moderate sexual dimorphism indicates limited male-male competition during breeding, which in turn suggests little aggregation of food or shelter in the environment inhabited by protocetids. CONCLUSIONS/SIGNIFICANCE: Discovery of a near-term fetus positioned for head-first delivery provides important evidence that early protocetid whales gave birth on land. This is consistent with skeletal morphology enabling Maiacetus to support its weight on land and corroborates previous ideas that protocetids were amphibious. Specimens this complete are virtual 'Rosetta stones' providing insight into functional capabilities and life history of extinct animals that cannot be gained any other way
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Supporting people with aphasia to âsettle into a new way to beâ: speech and language therapistsâ views on providing psychosocial support
Background: People with aphasia are at risk of becoming depressed and isolated. On-line surveys have found that the majority of Speech and Language Therapists (SLTs) lack confidence in addressing the psychological needs of people with aphasia.
Aims: To explore how SLTs conceptualise the scope of their role; barriers and facilitators to SLTs addressing psychosocial needs; and SLTsâ experiences of specialist training and support, and working with mental health professionals (MHPs).
Methods and procedures: Focus groups conducted in stroke healthcare settings. Purposive sampling was used in selecting sites so as to capture a range of experiences. Results were analysed using Framework Analysis.
Outcomes and Results: Twenty-three SLTs took part in six focus groups. Participantsâ psychosocial work included counselling-type interactions, psychoeducation, working with families, facilitating peer support, and training other healthcare professionals. There was a lack of consensus on the scope of the SLT role. Many expressed a sense of conflict, both perceiving it as valuable to spend time addressing psychological well-being, while simultaneously feeling uneasy if they deviated from âdirect SLTâ work. Barriers to addressing psychosocial wellbeing were: emotionally challenging nature of this work, particularly for those who felt unsupported; caseload and time pressures; attitude of senior managers and commissioners; difficulties measuring and documenting more âfluidâ psychosocial work; and the complexity of needs and backgrounds of some patients. Enabling factors were: specialist on-going support; peer support from colleagues; experience; support of management; and personal belief. Specialist training was valued. It changed how participants viewed the therapist-client relationship (more client-led); the assessment and goal setting process; and gave them more confidence to acknowledge client emotions. However, many felt that there was a need for on-going specialist advice, and to be able to see approaches modelled for this client group. In terms of mental health professionals (MHPs), a subset of stroke specialist clinical psychologists worked directly with people with marked aphasia and families, as well as supporting the multidisciplinary team to provide holistic care. However, a main theme was that participants perceived many MHPs did not consider people with aphasia as âappropriate candidatesâ for psychological input.
Conclusions and Implications: All participants cared about the emotional well-being of their clients; however, they identified a number of barriers to people with aphasia receiving appropriate psychological support. A cultural shift, whereby psychological care for people with aphasia is seen as valuable, feasible and necessary, delivered collaboratively by SLTs, MHPs and the wider team, may improve services
Acoustic Events in the Solar Atmosphere from Hinode/SOT NFI observations
We investigate the properties of acoustic events (AEs), defined as spatially
concentrated and short duration energy flux, in the quiet sun using
observations of a 2D field of view (FOV) with high spatial and temporal
resolution provided by the Solar Optical Telescope (SOT) onboard
\textit{Hinode}. Line profiles of Fe \textsc{i} 557.6 nm were recorded by the
Narrow band Filter Imager (NFI) on a FOV during 75 min with a
time step of 28.75 s and 0.08 pixel size. Vertical velocities were computed
at three atmospheric levels (80, 130 and 180 km) using the bisector technique
allowing the determination of energy flux in the range 3-10 mHz using two
complementary methods (Hilbert transform and Fourier power spectra). Horizontal
velocities were computed using local correlation tracking (LCT) of continuum
intensities providing divergences.
The net energy flux is upward. In the range 3-10 mHz, a full FOV space and
time averaged flux of 2700 W m (lower layer 80-130 km) and 2000 W
m (upper layer 130-180 km) is concentrated in less than 1% of the solar
surface in the form of narrow (0.3) AE. Their total duration (including rise
and decay) is of the order of s. Inside each AE, the mean flux is W m (lower layer) and W m (upper). Each
event carries an average energy (flux integrated over space and time) of J (lower layer) to J (upper). More than events
could exist permanently on the Sun, with a birth and decay rate of 3500
s. Most events occur in intergranular lanes, downward velocity regions,
and areas of converging motions.Comment: 18 pages, 10 figure
Bighorn Basin Coring Project (BBCP): a continental perspective on early Paleogene hyperthermals
During the summer of 2011, the Bighorn Basin Coring Project (BBCP) recovered over 900m of overlapping core from 3 different sites in late Paleocene to early Eocene fluvial deposits of northwestern Wyoming. BBCP cores are being used to develop high-resolution proxy records of the PaleoceneâEocene Thermal Maximum (PETM) and Eocene Thermal Maximum 2 (ETM2) hyperthermal events. These events are short-term, large magnitude global warming events associated with extreme perturbations to the earthâs carbon cycle. Although the PETM and ETM2 occurred ~55â52 million years ago, they are analogous in many ways to modern anthropogenic changes to the carbon cycle. By applying various sedimentological, geochemical, and palynological methods to the cores, we hope to better understand what caused these events, study the biogeochemical and ecological feedbacks that operated during them, and reveal precisely how they impacted continental environments.
Core recovery was > 98% in all holes and most drilling was carried out without fluid additives, showing that continuous coring of continental smectitic deposits like these can be achieved with minimal risk of contamination to molecular biomarkers. Cores were processed in the Bremen Core Repository where the science team convened for 17 days to carry out data collection and sampling protocols similar to IODP projects. Initial results show that the weathered horizon extends to as much as ~30m below the surface and variations in magnetic susceptibility within the cores record an interplay between grain size and pedogenesis. Previous investigations of outcrops near the BBCP drill sites allow detailed evaluation of the effects of weathering on common proxy methods. Studies of lithofacies, organic geochemistry, stable isotope geochemistry, calibrated XRF core scanning, paleomagnetics, and palynology are underway and will represent the highest resolution and most integrated proxy records of the PETM from a continental setting yet known. An extensive outreach program is in place to capitalize on the educational value associated with the Bighorn Basinâs unusually complete record of Phanerozoic earth history
Epistemic insights: Contemplating tensions between policy influences and creativity in school science
Creativity and the way it could be supported in schools is understood differently by policy makers, practitioners and scientists. This article reviews, with a chronological lens, the development of policies that include teaching creativity and teaching for creativity. The epistemic tensions between the intentions of government and the nature of creativity as it emerges in learning or scientific work is introduced and reflected upon. There have been more than nine key educational policies that have been introduced over the last 50 years. Each of these are considered in this article and related to the ways that creativity is understood and expected to be taught, supported or enacted in schools by policy makers. In light of the need to support creativity as a key twentyâfirstâcentury skill, to ultimately enable current students (who will become the next generation of scientists) to develop the capabilities to address global concerns, this article highlights issues related to this issue. Epistemic insights are offered that relate to the development of aspects of creativity, including questioning, developing alternate ideas, âseeingâ things differently, innovation, curiosity, problem solving and evaluating. The ways that policy related to creativity in science appears not to recognise how creativity can be reified in these ways in schools suggests the need for rapid review, especially in light of the upcoming international creativity tests in 2021
Lines of Descent: Kuhn and Beyond
yesThomas S. Kuhn is famous both for his work on the Copernican Revolution and his âparadigmâ view of scientific revolutions. But Kuhn later abandoned the notion of paradigm (and related notions) in favour of a more âevolutionaryâ view of the history of science. Kuhnâs position therefore moved closer to âcontinuityâ models of scientific progress, for instance âchain-of-reasoningâ models, originally championed by D. Shapere. The purpose of this paper is to contribute to the debate around Kuhnâs new âdevelopmentalâ view and to evaluate these competing models with reference to some major innovations in the history of cosmology, from Copernicanism to modern cosmology. This evaluation is made possible through some unexpected overlap between Kuhnâs earlier discontinuity model and various versions of the later continuity models. It is the thesis of this paper that the âchain-of-reasoningâ model accounts better for the cosmological evidence than both Kuhnâs early paradigm model and his later developmental view of the history of science
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