3,995 research outputs found
Fast multi-image matching via density-based clustering
We consider the problem of finding consistent matches
across multiple images. Previous state-of-the-art solutions
use constraints on cycles of matches together with convex
optimization, leading to computationally intensive iterative
algorithms. In this paper, we propose a clustering-based
formulation. We first rigorously show its equivalence with
the previous one, and then propose QuickMatch, a novel
algorithm that identifies multi-image matches from a density
function in feature space. We use the density to order the
points in a tree, and then extract the matches by breaking this
tree using feature distances and measures of distinctiveness.
Our algorithm outperforms previous state-of-the-art methods
(such as MatchALS) in accuracy, and it is significantly faster
(up to 62 times faster on some bechmarks), and can scale to
large datasets (with more than twenty thousands features).Accepted manuscriptSupporting documentatio
Are specialized sperm function tests clinically useful in planning assisted reproductive technology?
40-year-old male patient and 32-year-old female partner, with a history of primary infertility of two years duration. The workup revealed idiopathic mild oligoasthenothe-ratozoospermia, and no apparent female infertility factors. The couple has failed three intrauterine insemination (IUI) cycles, planning more IUI cycles but also considering in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI)46111612
Study of the effect of pH, salinity and DOC on fluorescence of synthetic mixtures of freshwater and marine salts
In order to provide support for the discussion of the fate of organic matter in estuaries, a laboratory simulation was
performed by changing freshwater ionic strength, pH and organic matter content. The change in spectroscopic
characteristics caused by variations in salinity, pH and organic matter concentration in the filtered samples was
observed by UV-Vis and fluorescence spectroscopy. The increase in emission fluorescence intensity of dissolved
organic matter (DOM) due to increasing salinity (in the range 0 to 5 g l−1) is affected by the pH of the samples. The
emission fluorescence intensity at the three maxima observed in the fluorescence spectra, is linearly correlated with
dissolved organic carbon (DOC) concentration at several salinity values in the same sample. The increase in organic
matter concentration caused a shift in the emission peak wavelength at 410 nm for several salinity values.We
concluded that it is necessary to take into account the influence of salinity and pH on emission fluorescence of
dissolved organic matter if it is to be used as a tracer in estuarine or near shore areas
Supersymmetric type-III seesaw: lepton flavour violating decays and dark matter
We study a supersymmetric version of the seesaw mechanism type-III. The model
consists of the MSSM particle content plus three copies of 24 superfields. The
fermionic part of the SU(2) triplet contained in the 24 is responsible for the
type-III seesaw, which is used to explain the observed neutrino masses and
mixings. Complete copies of 24 are introduced to maintain gauge coupling
unification. These additional states change the beta functions of the gauge
couplings above the seesaw scale. Using mSUGRA boundary conditions we calculate
the resulting supersymmetric mass spectra at the electro-weak scale using full
2-loop renormalization group equations. We show that the resulting spectrum can
be quite different compared to the usual mSUGRA spectrum. We discuss how this
might be used to obtain information on the seesaw scale from mass measurements.
Constraints on the model space due to limits on lepton flavour violating decays
are discussed. The main constraints come from the bounds on the decay mu to e
and gamma but there are also regions where the decay tau to mu and gamma gives
stronger constraints. We also calculate the regions allowed by the dark matter
constraint. For the sake of completeness, we compare our results with those for
the supersymmetric seesaw type-II and, to some extent, with type-I.Comment: 32 pages, 16 eps figures. One ref. added; small changes in tex
Advances in Atomic Data for Neutron-Capture Elements
Neutron(n)-capture elements (atomic number Z>30), which can be produced in
planetary nebula (PN) progenitor stars via s-process nucleosynthesis, have been
detected in nearly 100 PNe. This demonstrates that nebular spectroscopy is a
potentially powerful tool for studying the production and chemical evolution of
trans-iron elements. However, significant challenges must be addressed before
this goal can be achieved. One of the most substantial hurdles is the lack of
atomic data for n-capture elements, particularly that needed to solve for their
ionization equilibrium (and hence to convert ionic abundances to elemental
abundances). To address this need, we have computed photoionization cross
sections and radiative and dielectronic recombination rate coefficients for the
first six ions of Se and Kr. The calculations were benchmarked against
experimental photoionization cross section measurements. In addition, we
computed charge transfer (CT) rate coefficients for ions of six n-capture
elements. These efforts will enable the accurate determination of nebular Se
and Kr abundances, allowing robust investigations of s-process enrichments in
PNe.Comment: To be published in IAU Symp. 283: Planetary Nebulae, an Eye to the
Future; 2 page
Predictive factors for sperm retrieval and sperm injection outcomes in obstructive azoospermia: do etiology, retrieval techniques and gamete source play a role?
Obstructive azoospermia is a relatively common male infertility condition. The main etiologies of obstructive azoospermia include congenital, surgical-derived, traumatic and post-infectious cases. Although seminal tract reconstruction is a cost-effective treatment in most cases, this approach may not be feasible or desired in some cases. In such cases, assisted reproduction techniques offer a method for achieving pregnancy, notably via sperm retrieval and intracytoplasmic sperm injection. This process requires several considerations and decisions to be made, including the cause and duration of obstruction, which sperm retrieval technique to use, and whether to use fresh or frozen-thawed sperm. We present a review of obstructive azoospermia and assisted reproduction techniques, highlighting the most relevant aspects of the decision-making process for use in clinical practice
Reproductive outcomes, including neonatal data, following sperm injection in men with obstructive and nonobstructive azoospermia: case series and systematic review
We compared pregnancy outcomes following intracytoplasmic sperm injection for the treatment of male infertility according to the type of azoospermia. First, we analyzed our data from 370 couples who underwent intracytoplasmic sperm injection using sperm from men with obstructive azoospermia and nonobstructive azoospermia, and the outcomes were compared to a group of 465 non-azoospermic infertile males. Then, we performed a systematic review of the published data on pregnancy and neonatal outcomes of children born after sperm injection using sperm from men with obstructive and nonobstructive azoospermia. Live birth rates were significantly lower in the nonobstructive azoospermia group (21.4%) compared with the obstructive azoospermia (37.5%) and ejaculated sperm (32.3%) groups. A total of 326 live births resulted in 427 babies born. Differences were not observed between the groups in gestational age, preterm birth, birth weight and low birth weight, although we noted a tendency towards poorer neonatal outcomes in the azoospermia categories. The overall perinatal death and malformation rates were 2.8% and 1.6%, respectively, and the results did not differ between the groups. We identified 20 published studies that directly compared pregnancy outcomes between obstructive azoospermia and nonobstructive azoospermia. Most of these studies were not designed to detect differences in live birth rates and had lower power to detect differences in less frequent outcomes, and the reporting of neonatal outcomes was unusual. The included studies reported either a decrease or no difference in pregnancy outcomes with intracytoplasmic sperm injection in cases of nonobstructive azoospermia and obstructive azoospermia. In general, no major differences were noted in short-term neonatal outcomes and congenital malformation rates between children from fathers with nonobstructive azoospermia and obstructive azoospermia
Caracterização das explorações de ovinos Serra da Estrela
A raça ovina serra da estrela tem o seu solar ao largo da nascente da bacia
hidrográfica do rio Mondego. Com um efectivo actual de cerca de 90000 cabeças e
encabeçamento de 35,8, esta raça autóctone de vocação predominantemente
leiteira, apresenta na rusticidade, uma característica fundamental para a sua
adaptação ao sistema semi-extensivo em que é explorada.
A alimentação é feita à base de pastagens naturais e melhoradas, forragens e
concentrados apenas durante o alavão.
Nos ovis predominam as construções próprias para o efeito, utilizando tanto o
sistema de camas de mato ou palha, como o ripado.
As condições higiosanitárias da maioria das explorações são ainda muito deficitárias
quer ao nível da qualidade das estruturas quer ao nível do maneio dos animais.
Aquando da selecção das explorações foram tomados em conta, entre outros,
critérios como a dimensão do efectivo, a indemnidade em relação à Brucelose, o tipo
de maneio, bem como a existência de suspeita clínica
O sobredimensionamento das explorações, a não existência de maternidades e
parques de recria, comedouros e bebedouros mal dimensionados, a ausência de
instalações para isolamento de animais doentes ou suspeitos, foram também
identificados como factores predisponentes ao aparecimento e manutenção nas
explorações de doenças com características epidemiológicas semelhantes à
paratuberculose.
O exame clínico de alguns animais destas explorações revelou a existência de
animais com acentuadas quebras de produção, emagrecimento progressivo, diarreia
terminal e edema intermandibular, compatíveis com um quadro sintomático de
Paratuberculose ovina.Agradecimentos: Ao Projecto Agro 786, Medida 8. Desenvolvimento Tecnológico e Demonstração. Acção 8.1-Desenvolvimento Experimental e Demonstração, bem como a todas as entidades nele interveniente
- …