303 research outputs found
Natural history of \u3ci\u3eCassida sphaerula\u3c/i\u3e Boheman, 1854 (Coleoptera: Chrysomelidae: Cassidinae: Cassidini) on \u3ci\u3eArctotheca prostrata\u3c/i\u3e (Salisb.) Britten (Asteraceae: Arctotidinae) in South Africa, with a checklist of South African Cassidinae (leaf-mining and tortoise beetles)
The tortoise beetle, Cassida sphaerula Boheman, 1854 (Coleoptera: Chrysomelidae: Cassidinae: Cassidini) is endemic to South Africa. Its endemic host, Arctotheca prostrata (Salisb.) Britten (Asteraceae) has been introduced in other countries where it is becoming invasive. Cassida sphaerula could provide a potential biocontrol of Arctotheca weeds as it spends the entire life cycle on this host. An intensive field study, with rearing, photography, and short films of C. sphaerula was conducted in its native habitat to document the life cycle. A checklist of Cassidinae genera in South Africa, along with 19 new host records for Cassidini species in South Africa are presented. Oothecae are simple, with few laminate membranes enclosing fewer than five eggs. There are five larval instars. Larvae and adults feed by making a series of cuts in the ventral cuticle, forming an arc, and they consume the mesophyll as the cuticle is rolled to one side. This creates many ventral craters, thickened on one margin with the rolled cuticle; these ventral craters correspond to ‘windows’ in the dorsal leaf surface where the dorsal cuticle is left intact. This unusual feeding pattern is known in three Cassida species, all in South Africa. Like many tortoise beetles, instar I initiates a feces-only shield on its paired caudal processes (= urogomophi); this construction is retained, along with exuviae, by subsequent instars. The shield construction was studied by film and dissections. This revealed that the columnar or pyramidal shield in this species has an exterior of dry or moist feces that obscures the central nested stack of exuviae, each exuviae compressed onto the caudal processes. Pupae may retain the entire larval shield of exuviae and feces or only the 5th instar exuviae; this behavioral flexibility in pupal shield retention is novel for tortoise beetles. Behaviors of C. sphaerula are discussed in the context of phylogenetic characters that can give evolutionary insights into the genus, tribe, and subfamily
Quantum optical coherence tomography with dispersion cancellation
We propose a new technique, called quantum optical coherence tomography
(QOCT), for carrying out tomographic measurements with dispersion-cancelled
resolution. The technique can also be used to extract the frequency-dependent
refractive index of the medium. QOCT makes use of a two-photon interferometer
in which a swept delay permits a coincidence interferogram to be traced. The
technique bears a resemblance to classical optical coherence tomography (OCT).
However, it makes use of a nonclassical entangled twin-photon light source that
permits measurements to be made at depths greater than those accessible via
OCT, which suffers from the deleterious effects of sample dispersion. Aside
from the dispersion cancellation, QOCT offers higher sensitivity than OCT as
well as an enhancement of resolution by a factor of 2 for the same source
bandwidth. QOCT and OCT are compared using an idealized sample.Comment: 19 pages, 4 figure
Humeral chondrosarcoma associated with lung metastases in a young dog - case report
ABSTRACT Chondrosarcoma, an unusual malignant neoplasm, develops in cartilaginous tissue and presents low rate of metastasis, mainly affecting the axial skeleton from the adult to senile dogs. In the face of unusual occurrence of chondrosarcoma in the long bones of young dogs, the present report aimed to describe it in the right humerus of a two-and-a-half-year-old Siberian Husky, attended at the Veterinary Hospital of the University of Franca, with limping of the right thoracic limb, for 20 days. The radiographic examination of the humerus showed bone lysis and periosteal proliferation. In the incisional biopsy, proliferation of atypical chondrocytes with diffuse distribution, interspersed with compact bone matrix, was observed. The amputation of the limb was performed, and the fragment histopathological analysis showed grade I chondrosarcoma. Periodic returns were made for neoplastic staging, and at 240 days after surgery lung metastases were detected, however, the tutor did not authorize chemotherapy and radiotherapy for financial reasons and due to the absence of respiratory symptoms so far (410 days after surgery). Although uncommon, chondrosarcoma can affect the long bones of young dogs, with clinical signs similar to other bone neoplasms, and, even with the radical limb amputation, can demonstrate systemic metastasis
Chiral symmetry restoration and the Z3 sectors of QCD
Quenched SU(3) lattice gauge theory shows three phase transitions, namely the
chiral, the deconfinement and the Z3 phase transition. Knowing whether or not
the chiral and the deconfinement phase transition occur at the same temperature
for all Z3 sectors could be crucial to understand the underlying microscopic
dynamics. We use the existence of a gap in the Dirac spectrum as an order
parameter for the restoration of chiral symmetry. We find that the spectral gap
opens up at the same critical temperature in all Z3 sectors in contrast to
earlier claims in the literature.Comment: 4 pages, 4 figure
The fraction of cancer attributable to ways of life, infections, occupation, and environmental agents in Brazil in 2020
Many human cancers develop as a result of exposure to risk factors related to the environment and ways of life. The aim of this study was to estimate attributable fractions of 25 types of cancers resulting from exposure to modifiable risk factors in Brazil. The prevalence of exposure to selected risk factors among adults was obtained from population-based surveys conducted from 2000 to 2008. Risk estimates were based on data drawn from metaanalyses or large, high quality studies. Population-attributable fractions (PAF) for a combination of risk factors, as well as the number of preventable deaths and cancer cases, were calculated for 2020. The known preventable risk factors studied will account for 34% of cancer cases among men and 35% among women in 2020, and for 46% and 39% deaths, respectively. The highest attributable fractions were estimated for tobacco smoking, infections, low consumption of fruits and vegetables, excess weight, reproductive factors, and physical inactivity. This is the first study to systematically estimate the fraction of cancer attributable to potentially modifiable risk factors in Brazil. Strategies for primary prevention of tobacco smoking and control of infection and the promotion of a healthy diet and physical activity should be the main priorities in policies for cancer prevention in the country. \ua9 2016 Azevedo e Silva et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
Comparison of three experimental designs employed in gentamicin microbiological assay through agar diffusion
Desempenho e rendimento de carcaça de bezerros alimentados com colostro fermentado, associado ao óleo de soja e zeranol
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