126 research outputs found
The influence of mathematics anxiety on pupils' choice of mental calculation strategies for two-digit addition and subtraction.
The ability to calculate mentally is a core skill in mathematics and is now a required feature of mathematics teaching. Mathematics anxiety is an established affective construct, associated with mathematical outcomes. The focus of this research is on the affective construct of mathematics anxiety and this may influence a pupil's choice of mental calculation strategy for two digit addition and subtraction. The main study (preceded by a pilot study) was divided into two parts and focused solely on Year 5 pupils; background data with permission, was obtained for each pupil. In the first part, pupils were given a mental calculation assessment, the Myself As Learner Scale (Burden, 1998) and the Mathematics Anxiety Scale for Children (Chiu Henry, 1990; Beasley, Long Natali, 2001). In the second part, the mental calculation strategies of pupils with either high or low mathematics anxiety was explored individually through a series of two digit addition and subtraction questions. Pupil responses were recorded, transcribed and classified. Strategy classification particularly distinguished pupils partitioning both two digit numbers and only one of the two digit numbers. Pupils with high mathematics anxiety tend to use lower order (less effective) strategies, whereas pupils with low mathematics anxiety tend to use higher order (more effective) strategies. No gender differences were found regarding strategy use. When controlled for mathematical competence, low mathematics anxious pupils produced more accurate mental calculation, whereas high mathematics anxious pupils produced less accurate mental calculations. Implications for Educational Psychologists and teachers in schools are discussed
Finite Density Fat QCD
Lattice formulation of Finite Baryon Density QCD is problematic from computer
simulation point of view; it is well known that for light quark masses the
reconstructed partition function fails to be positive in a wide region of
parameter space. For large bare quark masses, instead, it is possible to obtain
more sensible results; problems are still present but restricted to a small
region. We present evidence for a saturation transition independent from the
gauge coupling and for a transition line that, starting from the
temperature critical point at , moves towards smaller with
increasing as expected from simplified phenomenological arguments.Comment: 14 pages, 10 figure
Quenched QCD at finite density
Simulations of quenched at relatively small but {\it nonzero} chemical
potential on lattices indicate that the nucleon
screening mass decreases linearly as increases predicting a critical
chemical potential of one third the nucleon mass, , by extrapolation.
The meson spectrum does not change as increases over the same range, from
zero to . Past studies of quenched lattice QCD have suggested that
there is phase transition at . We provide alternative
explanations for these results, and find a number of technical reasons why
standard lattice simulation techniques suffer from greatly enhanced
fluctuations and finite size effects for ranging from to
. We find evidence for such problems in our simulations, and suggest
that they can be surmounted by improved measurement techniques.Comment: 23 pages, Revte
Non-Commutativity of the Zero Chemical Potential Limit and the Thermodynamic Limit in Finite Density Systems
Monte Carlo simulations of finite density systems are often plagued by the
complex action problem. We point out that there exists certain
non-commutativity in the zero chemical potential limit and the thermodynamic
limit when one tries to study such systems by reweighting techniques. This is
demonstrated by explicit calculations in a Random Matrix Theory, which is
thought to be a simple qualitative model for finite density QCD. The
factorization method allows us to understand how the non-commutativity, which
appears at the intermediate steps, cancels in the end results for physical
observables.Comment: 7 pages, 9 figure
Pathologies of Quenched Lattice QCD at non--zero Density and its Effective Potential
We simulate lattice QCD at non--zero baryon density and zero temperature in
the quenched approximation, both in the scaling region and in the infinite
coupling limit. We investigate the nature of the forbidden region -- the range
of chemical potential where the simulations grow prohibitively expensive, and
the results, when available, are puzzling if not unphysical. At weak coupling
we have explored the sensitivity of these pathologies to the lattice size, and
found that using a large lattice () does not remove them. The
effective potential sheds considerable light on the problems in the
simulations, and gives a clear interpretation of the forbidden region. The
strong coupling simulations were particularly illuminating on this point.Comment: 49 pages, uu-encoded expanding to postscript;also available at
ftp://hlrz36.hlrz.kfa-juelich.de/pub/mpl/hlrz72_95.p
Relative growth in the fiddler crab Uca uruguayensis Nobili, 1901 (Brachyura, Ocypodidae) from Garças River mangrove, Guaratuba Bay, southern Brazil
A deep dive into the ecology of Gamay (Botany Bay, Australia): current knowledge and future priorities for this highly modified coastal waterway
Context: Gamay is a coastal waterway of immense social, cultural and ecological value. Since European settlement, it has become a hub for industrialisation and human modification. There is growing desire for ecosystem-level management of urban waterways, but such efforts are often challenged by a lack of integrated knowledge.
Aim and methods: We systematically reviewed published literature and traditional ecological knowledge (TEK), and consulted scientists to produce a review of Gamay that synthesises published knowledge of Gamay’s aquatic ecosystem to identify knowledge gaps and future research opportunities.
Key results: We found 577 published resources on Gamay, of which over 70% focused on ecology. Intertidal rocky shores were the most studied habitat, focusing on invertebrate communities. Few studies considered multiple habitats or taxa. Studies investigating cumulative human impacts, long-term trends and habitat connectivity are lacking, and the broader ecological role of artificial substrate as habitat in Gamay is poorly understood. TEK of Gamay remains a significant knowledge gap. Habitat restoration has shown promising results and could provide opportunities to improve affected habitats in the future.
Conclusion and implications: This review highlights the extensive amount of knowledge that exists for Gamay, but also identifies key gaps that need to be filled for effective management
Sophora tomentosa e Crotalaria vitellina (Fabaceae): biologia reprodutiva e interações com abelhas na restinga de Ubatuba, São Paulo
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