1,480 research outputs found
Object segmentation in depth maps with one user click and a synthetically trained fully convolutional network
With more and more household objects built on planned obsolescence and
consumed by a fast-growing population, hazardous waste recycling has become a
critical challenge. Given the large variability of household waste, current
recycling platforms mostly rely on human operators to analyze the scene,
typically composed of many object instances piled up in bulk. Helping them by
robotizing the unitary extraction is a key challenge to speed up this tedious
process. Whereas supervised deep learning has proven very efficient for such
object-level scene understanding, e.g., generic object detection and
segmentation in everyday scenes, it however requires large sets of per-pixel
labeled images, that are hardly available for numerous application contexts,
including industrial robotics. We thus propose a step towards a practical
interactive application for generating an object-oriented robotic grasp,
requiring as inputs only one depth map of the scene and one user click on the
next object to extract. More precisely, we address in this paper the middle
issue of object seg-mentation in top views of piles of bulk objects given a
pixel location, namely seed, provided interactively by a human operator. We
propose a twofold framework for generating edge-driven instance segments.
First, we repurpose a state-of-the-art fully convolutional object contour
detector for seed-based instance segmentation by introducing the notion of
edge-mask duality with a novel patch-free and contour-oriented loss function.
Second, we train one model using only synthetic scenes, instead of manually
labeled training data. Our experimental results show that considering edge-mask
duality for training an encoder-decoder network, as we suggest, outperforms a
state-of-the-art patch-based network in the present application context.Comment: This is a pre-print of an article published in Human Friendly
Robotics, 10th International Workshop, Springer Proceedings in Advanced
Robotics, vol 7. The final authenticated version is available online at:
https://doi.org/10.1007/978-3-319-89327-3\_16, Springer Proceedings in
Advanced Robotics, Siciliano Bruno, Khatib Oussama, In press, Human Friendly
Robotics, 10th International Workshop,
An Intelligent Multicriteria Model for Diagnosing Dementia in People Infected with Human Immunodeficiency Virus
Hybrid models to detect dementia based on Machine Learning can provide accurate
diagnoses in individuals with neurological disorders and cognitive complications caused by Human
Immunodeficiency Virus (HIV) infection. This study proposes a hybrid approach, using Machine
Learning algorithms associated with the multicriteria method of Verbal Decision Analysis (VDA).
Dementia, which affects many HIV-infected individuals, refers to neurodevelopmental and mental
disorders. Some manuals standardize the information used in the correct detection of neurological
disorders with cognitive complications. Among the most common manuals used are the DSM-5
(Diagnostic and Statistical Manual of Mental Disorders, 5th edition) of the American Psychiatric
Association and the International Classification of Diseases, 10th edition (ICD-10)—both published
byWorld Health Organization (WHO). The model is designed to explore the predictive of specific
data. Furthermore, a well-defined database data set improves and optimizes the diagnostic models
sought in the research.info:eu-repo/semantics/publishedVersio
Detection of RHDV strains in the Iberian hare (Lepus granatensis): earliest evidence of rabbit lagovirus cross-species infection
This is an Open Access article distributed under the terms of the Creative Commons Attribution License.-- et al.Rabbit hemorrhagic disease virus (RHDV) is a highly lethal Lagovirus, family Caliciviridae, that threatens European rabbits (Oryctolagus cuniculus). Although a related virus severely affects hares, cross-species infection was only recently described for new variant RHDV in Cape hares (Lepus capensis mediterraneus). We sequenced two strains from dead Iberian hares (Lepus granatensis) collected in the 1990s in Portugal. Clinical signs were compatible with a Lagovirus infection. Phylogenetic analysis of the complete capsid gene positioned them in the RHDV genogroup that circulated on the Iberian Peninsula at that time. This is the earliest evidence of RHDV affecting a species other than European rabbits.This work was supported by FCT (Fundação para a Ciência e a Tecnologia; research project ref.: FCT-ANR/BIABIC/0043/2012). FCT also supported the doctoral grants of AML and AP (refs.: SFRH/BD/78738/2011 and SFRH/BD/71252/2010) and the FCT Investigator grant of JA (ref.: IF/01396/2013). “Genomics Applied To Genetic Resources” co-financed by North Portugal Regional Operational Programme 2007/2013
(ON.2 – O Novo Norte), under the National Strategic Reference Framework (NSRF), through the European Regional Development Fund (ERDF), also supported this work.Peer Reviewe
Functional characterization and evolution ofPTH/PTHrP receptors: insights from the chicken
The parathyroid hormone (PTH)-family consists of a group of structurally related factors that regulate calcium and bone homeostasis and are also involved in development of organs such as the heart, mammary gland and immune system. They interact with specific members of family 2 B1 G-protein coupled receptors (GPCRs), which have been characterised in teleosts and mammals. Two PTH/PTHrP receptors, PTH1R and PTH2R exist in mammals and in teleost fish a further receptor PTH3R has also been identified. Recently in chicken, PTH-family members involved in calcium transport were characterized and specific PTHRs are suggested to exist although they have not yet been isolated or functionally characterized. The aim of this study is to further explore the evolution and function of the vertebrate PTH/PTHrP system through the isolation, phylogenetic analysis and functional characterization of the chicken receptors.
Results
Two PTHRs were isolated in chicken and sequence comparison and phylogenetic analysis indicate that the chicken receptors correspond to PTH1R and PTH3R, which emerged prior to the teleost/tetrapod divergence since they are present in cartilaginous fish. The vertebrate PTH2R receptor and its ligand TIP39 have been lost from bird genomes. Chicken PTH1R and PTH3R have a divergent and widespread tissue expression and are also evident in very early embryonic stages of development. Receptor stimulation studies using HEK293 cells stably expressing the chicken PTH1R and PTH3R and monitoring cAMP production revealed they are activated by chicken 1–34 N-terminal PTH-family peptides in a dose dependent manner. PTH-L and PTHrP were the most effective peptides in activating PTH1R (EC50 = 7.7 nM and EC50 = 22.7 nM, respectively). In contrast, PTH-L (100 nM) produced a small cAMP accumulation on activation of PTH3R but PTHrP and PTH (EC50 = 2.5 nM and EC50 = 22.1 nM, respectively) readily activated the receptor. PTHrP also stimulated intracellular Ca2+ accumulation on activation of PTH1R but not PTH3R.
Conclusion
Two PTHR homologues of the vertebrate PTH1R and PTH3R were isolated and functionally characterized in chicken. Their distinct pattern of expression during embryo development and in adult tissues, together with their ligand preference, suggests that they have acquired specific functions, which have contributed to their maintenance in the genome. PTH2R and its activating ligand, TIP39, are absent from bird genomes. Nonetheless identification of putative PTH2R and TIP39 in the genome of an ancient agnathan, lamprey, suggests the PTH/PTHrP ligand and receptor family was already present in an early basal paraphyletic group of vertebrates and during the vertebrate radiation diverged via gene/genome duplication and deletion events. Knowledge of the role PTH/PTHrP system in early vertebrates will help to establish evolution of function.Peer Reviewe
Chaos in the square billiard with a modified reflection law
The purpose of this paper is to study the dynamics of a square billiard with
a non-standard reflection law such that the angle of reflection of the particle
is a linear contraction of the angle of incidence. We present numerical and
analytical arguments that the nonwandering set of this billiard decomposes into
three invariant sets, a parabolic attractor, a chaotic attractor and a set
consisting of several horseshoes. This scenario implies the positivity of the
topological entropy of the billiard, a property that is in sharp contrast with
the integrability of the square billiard with the standard reflection law.Comment: 17 figure
Hybrid model for early identification post-Covid-19 sequelae
Artificial Intelligence techniques based on Machine Learning algorithms, Neural Networks and Naïve Bayes can optimise the diagnostic process of the SARS-CoV-2 or Covid-19. The most significant help of these techniques is analysing data recorded by health professionals when treating patients with this disease. Health professionals' more specific focus is due to the reduction in the number of observable signs and symptoms, ranging from an acute respiratory condition to severe pneumonia, showing an efficient form of attribute engineering. It is important to note that the clinical diagnosis can vary from asymptomatic to extremely harsh conditions. About 80% of patients with Covid-19 may be asymptomatic or have few symptoms. Approximately 20% of the detected cases require hospital care because they have difficulty breathing, of which about 5% may require ventilatory support in the Intensive Care Unit. Also, the present study proposes a hybrid approach model, structured in the composition of Artificial Intelligence techniques, using Machine Learning algorithms, associated with multicriteria methods of decision support based on the Verbal Decision Analysis methodology, aiming at the discovery of knowledge, as well as exploring the predictive power of specific data in this study, to optimise the diagnostic models of Covid-19. Thus, the model will provide greater accuracy to the diagnosis sought through clinical observation.info:eu-repo/semantics/publishedVersio
Application of chitosan-based coatings on frozen salmon - Sensory assessment and retail simulation approach
GLUPOR 12 - 12nd International Meeting of the Portuguese Carbohydrate Chemistry GroupDue
to
an
increase
in
fish
consumption
over
the
past
years
, in comb
ination
with
the
perishable
nature
of
fish
, the
fish
industry
has
given
an
added
focus
on
the
improvement
of
the
currently
used
fish
preservation
techniques.
Chitosan
coatings
may
add
improvements
to
the
traditional
water
glazing
, name
ly
in
physical
and
ant
i- microbial
protection
,
allowing
for
shelf
life
extension.
Nevertheless
, during
retail
storage
, frozen
fish
products
can
suffer
temperature
variations
that
lead
to
a decrease
in
quality.
These
temperature
var
iations
can
be
caused
by
a multitude
of
reasons
,
some
of
which
are
easy
to
control
,
while
others
are
due
to
unforeseen
circumstances
.
In
either
case
, thermal
stress
can
often
affect
frozen
fish
products
and
this
effect
is
of
considerable
importance
.
This
work
was
meant
to
determ
ine
the
influence
of
chitosan coatings
in
the
organoleptic
characteristics
of
salmon
as
well
as
report
a strategy
to
help
mitigate
the
effects
of
thermal
stress
of
frozen
fish
samples
.A 15
g/L
chitosan
solution
was
applied
on
frozen
salmon
samples through
dipping
at
a temperature
of
8
°C,
wi
th
a dipping
time
of
10
s; water
glazing
was
applied
as
blank
treatment
at
0.5 °C,
with
a dipping
time
of
40
s.
Some
of
the
samples
were
submitted
to
retail-
simulated
thermal
stress
conditions
(i.
e. a temperature
variation
of
-15
°C
to
-5
°C
was
enforced
),
and
studied
during
a
70-days
long
experiment
,
while
others
were
used
to
assess
the
sensory
properties
of
chitosan
coat
ings
on
Atlantic
salmon
(Sa/mo
salar)
and
were
compared
with
uncoated
and
water
glazed
samples
over
a six-month
storage
period
at
-18
°C.
Retail
simulation
samples
were
tested
for
variations
in
pH
, coat
i
ng
loss
and
color
,
while
samples
used
for
sensory
analys
is
were
evaluated
by
a sensory
panel
(frozen
, frozen+thawed
and
frozen
+thawed+cooked
samples
were
assessed
,) regarding
its
organolept
ic properties
, and
textural
analysis
, by
means
of
a TPA
(texture
profile
analys
is
).
Samples
analys
is common
to
both
exper
iments
were
microbiological
stabi
lity, assessed
through
TVC
(ISO
4833-1
:2013
standard)
, and
chemical
stability
, determined
as
TVB-N
(N
P
2930
:2009
standard
).
Through
coating
loss,
it
was
possible
to
verify
that
chitosan
coatings
offer
better
protect
ion,
with
water
glazed
samples
becoming
virtually
unprotected
after
the
evaluation
period,
with
losses
of
more
than
80
%
of
its
glazing
,
while
chitosan
coated
samples
maintained
50
%
of
its
coating.
Extrapolat
i
ng
this
data
to
complete
loss
of
water
glazing
shows
an
increase
in
shel
f life
of
at
le
ast
26
%
in
chitosan
coated
samples.
No
significant
changes
between
samples
were
obtained
in
the
other
parameters
assessed
. The
anti-m
icrobial
effect
of
chitosan
was
confirmed
through
TVC
which
showed
a reduction
in
microbial
counts
in
chitosan
coated
samp
les
,
whi
le
while
TVB-N
results
showed
to
remain
stable
, for
both
experiments
. The
proven
anti
-
microbial
effect
of
chitosan
coated
samples
in
conjunction
with
a slower
coating
loss
leads
to
an
expected
increase
in
shelf
life ,
even
in
unforeseen
circumstances
of
temperature
change
in
retail
transportation.
Textural
results
from
the
TPA
analysis
showed
no
significant
differences
between
different
coatings.
Results
of
the
trained
panel
indicated
that
for
frozen
samples
ch
itosan
was
the
preferred
choice
,
while
no
significant
differences
existed
between
chitosan
-coated
and
glazed
samples
in
thawed
and
cooked
samples.
Flavor
diffu
sion
from
the
chitosan
coating
to
the
samples
was
assessed
by
Principal
Component
Analysis
and
no
correlation
between
coating
type
and
sample
flavor
could
be
established
, meaning
that
no
chitosan
flavor
was
detected
by
the
panellists.Portuguese Foundation for Science and Technology (FCT) under
the scope of the strategic funding of UID/BIO/044691/2013
unit and COMPETE 2020 (POCl-01-0145-FEDER-006684) and BioTecNorte
operation (NORTE-01-0145-FEDER-000004) funded by the European Regional Development Fund under
the
scope
of
Norte2020
-
Programa
Operacional
Regional
do
Norteinfo:eu-repo/semantics/publishedVersio
Brain Computer Interface Systems for Neurorobotics: Methods and Applications
info:eu-repo/semantics/publishedVersio
Have the cake and eat it: optimizing nondestructive DNA metabarcoding of macroinvertebrate samples for freshwater biomonitoring
Resource ArticleDNA metabarcoding can contribute to improving cost‐effectiveness and accuracy of
biological assessments of aquatic ecosystems, but significant optimization and standardization
efforts are still required to mainstream its application into biomonitoring
programmes. In assessments based on freshwater macroinvertebrates, a key challenge
is that DNA is often extracted from cleaned, sorted and homogenized bulk
samples, which is time‐consuming and may be incompatible with sample preservation
requirements of regulatory agencies. Here, we optimize and evaluate metabarcoding
procedures based on DNA recovered from 96% ethanol used to preserve field
samples and thus including potential PCR inhibitors and nontarget organisms. We
sampled macroinvertebrates at five sites and subsampled the preservative ethanol at
1 to 14 days thereafter. DNA was extracted using column‐based enzymatic (TISSUE)
or mechanic (SOIL) protocols, or with a new magnetic‐based enzymatic protocol
(BEAD), and a 313‐bp COI fragment was amplified. Metabarcoding detected at least
200 macroinvertebrate taxa, including most taxa detected through morphology and
for which there was a reference barcode. Better results were obtained with BEAD
than SOIL or TISSUE, and with subsamples taken 7–14 than 1–7 days after sampling,
in terms of DNA concentration and integrity, taxa diversity and matching between
metabarcoding and morphology. Most variation in community composition was explained
by differences among sites, with small but significant contributions of subsampling
day and extraction method, and negligible contributions of extraction and
PCR replication. Our methods enhance reliability of preservative ethanol as a potential
source of DNA for macroinvertebrate metabarcoding, with a strong potential application
in freshwater biomonitoringinfo:eu-repo/semantics/publishedVersio
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