11,160 research outputs found
Effect of Edwardsiella ictaluri Infection on Plasma Corticosterone Levels in Channel Catfish (Ictalurus punctatus)
Channel catfish (Ictalurus punctatus) were innoculated with a new host specific bacterium, Edwardsiella ictaluri, to observe the influence of bacterial infection on plasma corticosterone levels at various temperatures. The fish were innoculated intraperitoneally. The infected fish were separated from the controls. Plasma corticosterone concentrations were determined by radioimmunoassay. The plasma corticosterone concentrations in non-innoculated catfish were about 6.15 ng/ml and nearly 5.63 ng/ml in the infected fish. The lower level of the hormone in the infected catfish was not significantly different from the control level. High temperature was a stress factor which increased plasma corticosterone levels whereas E. ictaluri retarded the response of corticosterone secreting cells of the fish kidneys
Flip, feedback and fly: Using LOOP to Enhance the Professional Experience of Initial Teacher Education
The Australian Professional Teaching Standards require pre-service teachers to complete a minimum number of days of professional experience in order to graduate. Problems can arise, however, when the evaluation of their professional experience against the Standards shifts from the providers of teacher education programmes to school-based supervising teachers. The Lesson Observation On-line Platform (LOOP) begins to address these problems by utilising a secure, shared digital platform to facilitate evidence-based evaluation of the performance of pre-service teachers. In this research, we evaluated the potential of LOOP to assess pre-service teachers against the Standards as well as to enhance the professional development of both pre-service teachers and their supervising teachers. The responses from two pre-service teachers and their supervising teachers demonstrate that the methodological matters can be easily overcome. Nevertheless our findings indicate that there are several practical issues that need to be overcome if LOOP were to be fully successful
LINE-1 Endonuclease-Dependent Retrotranspositional Events Causing Human Genetic Disease: Mutation Detection Bias and Multiple Mechanisms of Target Gene Disruption
LINE-1 (L1) elements are the most abundant autonomous non-LTR retrotransposons in the human genome. Having recently performed a meta-analysis of L1 endonuclease-mediated retrotranspositional events causing human genetic disease, we have extended this study by focusing on two key issues, namely, mutation detection bias and the multiplicity of mechanisms of target gene disruption. Our analysis suggests that whereas an ascertainment bias may have generally militated against the detection of autosomal L1-mediated insertions, autosomal L1 direct insertions could have been disproportionately overlooked owing to their unusually large size. Our analysis has also indicated that the mechanisms underlying the functional disruption of target genes by L1-mediated retrotranspositional events are likely to be dependent on several different factors such as the type of insertion (L1 direct, L1 trans-driven Alu, or SVA), the precise locations of the inserted sequences within the target gene regions, the length of the inserted sequences, and possibly also their orientation
Is the NIH policy for sharing GWAS data running the risk of being counterproductive?
Through their current policy on data sharing, the National Institutes of Health (NIH) are inadvertently placing a serious and potentially insuperable burden upon non-US researchers who perform patient-based genomics studies in collaboration with US institutions. Because this policy could adversely affect future transnational scientific collaborations, we explore some of its likely consequences and suggest possible courses of remedial action wherever feasible
Resolving the Surfaces of Extrasolar Planets With Secondary Eclipse Light Curves
We present a method that employs the secondary eclipse light curves of
transiting extrasolar planets to probe the spatial variation of their thermal
emission. This technique permits an observer to resolve the surface of the
planet without the need to spatially resolve its central star. We evaluate the
feasibility of this technique for the HD 209458 system [..]. We consider two
representations of the planetary thermal emission; a simple model parameterized
by a sinusoidal dependence on longitude and latitude, as well as the results of
a three-dimensional dynamical simulation of the planetary atmosphere previously
published by Cooper & Showman. We find that observations of the secondary
eclipse light curve are most sensitive to a longitudinal offset in the
geometric and photometric centroids of the hemisphere of the planet visible
near opposition. To quantify this signal, we define a new parameter, the
``uniform time offset,'' which measures the time lag between the observed
secondary eclipse and that predicted by a planet with a uniform surface flux
distribution. We compare the predicted amplitude of this parameter for HD
209458 with the precision with which it could be measured with IRAC. We find
that IRAC observations at 3.6um a single secondary eclipse should permit
sufficient precision to confirm or reject the Cooper & Showman model of the
surface flux distribution for this planet. We quantify the signal-to-noise
ratio for this offset in the remaining IRAC bands (4.5um, 5.8um, and 8.0um),
and find that a modest improvement in photometric precision (as might be
realized through observations of several eclipse events) should permit a
similarly robust detection.Comment: AASTeX 5.2, 24 pages, 5 figures, accepted for publication in ApJ; v2:
clarifications, updated to version accepted by ApJ; v3: try to reduce spacin
Emerging genotype-phenotype relationships in patients with large NF1 deletions.
The most frequent recurring mutations in neurofibromatosis
type 1 (NF1) are large deletions encompassing
the NF1 gene and its flanking regions (NF1 microdeletions).
The majority of these deletions encompass 1.4-Mb
and are associated with the loss of 14 protein-coding genes
and four microRNA genes. Patients with germline type-1
NF1 microdeletions frequently exhibit dysmorphic facial
features, overgrowth/tall-for-age stature, significant delay
in cognitive development, large hands and feet, hyperflexibility
of joints and muscular hypotonia. Such patients
also display significantly more cardiovascular anomalies
as compared with patients without large deletions and
often exhibit increased numbers of subcutaneous, plexiform
and spinal neurofibromas as compared with the general
NF1 population. Further, an extremely high burden of
internal neurofibromas, characterised by >3000 ml tumour
volume, is encountered significantly, more frequently,
in non-mosaic NF1 microdeletion patients than in NF1
patients lacking such deletions. NF1 microdeletion patients
also have an increased risk of malignant peripheral nerve
sheath tumours (MPNSTs); their lifetime MPNST risk is
16–26%, rather higher than that of NF1 patients with intragenic
NF1 mutations (8–13%). NF1 microdeletion patients,
therefore, represent a high-risk group for the development
of MPNSTs, tumours which are very aggressive and difficult to treat. Co-deletion of the SUZ12 gene in addition
to NF1 further increases the MPNST risk in NF1 microdeletion
patients. Here, we summarise current knowledge
about genotype–phenotype relationships in NF1 microdeletion
patients and discuss the potential role of the genes
located within the NF1 microdeletion interval whose haploinsufficiency may contribute to the more severe clinical phenotyp
Measuring atomic NOON-states and using them to make precision measurements
A scheme for creating NOON-states of the quasi-momentum of ultra-cold atoms
has recently been proposed [New J. Phys. 8, 180 (2006)]. This was achieved by
trapping the atoms in an optical lattice in a ring configuration and rotating
the potential at a rate equal to half a quantum of angular momentum . In this
paper we present a scheme for confirming that a NOON-state has indeed been
created. This is achieved by spectroscopically mapping out the anti-crossing
between the ground and first excited levels by modulating the rate at which the
potential is rotated. Finally we show how the NOON-state can be used to make
precision measurements of rotation.Comment: 14 preprint pages, 7 figure
The DEEP2 Galaxy Redshift Survey: Redshift Identification of Single-Line Emission Galaxies
We present two methods for determining spectroscopic redshifts of galaxies in
the DEEP2 survey which display only one identifiable feature, an emission line,
in the observed spectrum ("single-line galaxies"). First, we assume each single
line is one of the four brightest lines accessible to DEEP2: Halpha, [OIII]
5007, Hbeta, or [OII] 3727. Then, we supplement spectral information with BRI
photometry. The first method, parameter space proximity (PSP), calculates the
distance of a single-line galaxy to galaxies of known redshift in (B-R), (R-I),
R, observed wavelength parameter space. The second method is an artificial
neural network (ANN). Prior information, such as allowable line widths and
ratios, rules out one or more of the four lines for some galaxies in both
methods. Based on analyses of evaluation sets, both methods are nearly perfect
at identifying blended [OII] doublets. Of the lines identified as Halpha in the
PSP and ANN methods, 91.4% and 94.2% respectively are accurate. Although the
methods are not this accurate at discriminating between [OIII] and Hbeta, they
can identify a single line as one of the two, and the ANN method in particular
unambiguously identifies many [OIII] lines. From a sample of 640 single-line
spectra, the methods determine the identities of 401 (62.7%) and 472 (73.8%)
single lines, respectively, at accuracies similar to those found in the
evaluation sets.Comment: 11 pages, 6 figures, accepted to Ap
Toward a Theory of Causation for Interpreting Neural Code Models
Neural Language Models of Code, or Neural Code Models (NCMs), are rapidly
progressing from research prototypes to commercial developer tools. As such,
understanding the capabilities and limitations of such models is becoming
critical. However, the abilities of these models are typically measured using
automated metrics that often only reveal a portion of their real-world
performance. While, in general, the performance of NCMs appears promising,
currently much is unknown about how such models arrive at decisions. To this
end, this paper introduces , a post hoc interpretability method
specific to NCMs that is capable of explaining model predictions.
is based upon causal inference to enable programming language-oriented
explanations. While the theoretical underpinnings of are extensible
to exploring different model properties, we provide a concrete instantiation
that aims to mitigate the impact of spurious correlations by grounding
explanations of model behavior in properties of programming languages. To
demonstrate the practical benefit of , we illustrate the insights
that our framework can provide by performing a case study on two popular deep
learning architectures and ten NCMs. The results of this case study illustrate
that our studied NCMs are sensitive to changes in code syntax. All our NCMs,
except for the BERT-like model, statistically learn to predict tokens related
to blocks of code (\eg brackets, parenthesis, semicolon) with less confounding
bias as compared to other programming language constructs. These insights
demonstrate the potential of as a useful method to detect and
facilitate the elimination of confounding bias in NCMs.Comment: Accepted to appear in IEEE Transactions on Software Engineerin
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