2,373 research outputs found
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Knitted waveguide antenna
This paper presents the design of a knitted slotted waveguide antenna and its improvement. The antenna is developed originally from a textile elliptical waveguide and it has a resonant frequency at 9.15GHz with 80MHz bandwidth. Then, slight structural adjustments are taken to improve the antenna’s performance. Moreover, the measured results show that the optimized slotted waveguide antenna working at 9.18GHz with 170 MHz bandwidth has a more directional radiation pattern with a higher gain. The antenna was designed and simulated in CST Microwave Studio 2012
On the Semantics of Snapshot Isolation
Snapshot isolation (SI) is a standard transactional consistency model used in
databases, distributed systems and software transactional memory (STM). Its
semantics is formally defined both declaratively as an acyclicity axiom, and
operationally as a concurrent algorithm with memory bearing timestamps.
We develop two simpler equivalent operational definitions of SI as lock-based
reference implementations that do not use timestamps. Our first locking
implementation is prescient in that requires a priori knowledge of the data
accessed by a transaction and carries out transactional writes eagerly
(in-place). Our second implementation is non-prescient and performs
transactional writes lazily by recording them in a local log and propagating
them to memory at commit time. Whilst our first implementation is simpler and
may be better suited for developing a program logic for SI transactions, our
second implementation is more practical due to its non-prescience. We show that
both implementations are sound and complete against the declarative SI
specification and thus yield equivalent operational definitions for SI.
We further consider, for the first time formally, the use of SI in a context
with racy non-transactional accesses, as can arise in STM implementations of
SI. We introduce robust snapshot isolation (RSI), an adaptation of SI with
similar semantics and guarantees in this mixed setting. We present a
declarative specification of RSI as an acyclicity axiom and analogously develop
two operational models as lock-based reference implementations (one eager, one
lazy). We show that these operational models are both sound and complete
against the declarative RSI model
The morphological discrimination of microfilariae of Onchocerca volvulus from Mansonella ozzardi.
There is no published account which allows the morphological discrimination of microfilariae of Onchocerca volvulus and M. ozzardi from each other. However, they occur together in parts of Brazil and Venezuela, and presumably there is always the possibility that migration could establish new sympatric populations in the future. The objective of this study was to evaluate simple morphological characters that might be used for species-diagnosis of microfilariae. The conclusions were that the location of microfilariae in the blood or skin, the body size and the nucleation of the nerve ring are expected to be useful first indications of species identity, but cannot be used for confident diagnosis. The structure of the cephalic armature (stained with alcian blue) seems to be species specific, but is of limited application because it is often difficult to see. However, the pattern of nucleation of the tail (as expressed by the ratio of the length of the terminal nucleus compared with the length of the tail space) is distinctive and is expected to be diagnostic
Moisture effects on a knitted waveguide
Previously, we proposed a knitted textile waveguide working at X-band. Such wearable devices will experience various environmental conditions such as getting wet when applied in practice. In this paper, we have investigated the impact of moisture on the performance of a knitted textile waveguide. The results show that moisture has significant influences on the knitted waveguide's performance. Therefore, the knitted waveguide needs to be water-proofed properly in real-life applications
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Knitted textile waveguide bending
This paper presents the performance of a knitted textile waveguide under different bending conditions. The waveguide is designed to operate at X-band and consists of a textile sleeve and knitted polyester inside. S21 of the bent knitted waveguide is compared to that of the straight knitted waveguide in both simulation and measurement
Prevalence and intensity of Haemoproteus columbae in three species of wild doves from Brazil
Deficiency in origin licensing proteins impairs cilia formation: implications for the aetiology of meier-gorlin syndrome
Mutations in ORC1, ORC4, ORC6, CDT1, and CDC6, which encode proteins required for DNA replication origin licensing, cause Meier-Gorlin syndrome (MGS), a disorder conferring microcephaly, primordial dwarfism, underdeveloped ears, and skeletal abnormalities. Mutations in ATR, which also functions during replication, can cause Seckel syndrome, a clinically related disorder. These findings suggest that impaired DNA replication could underlie the developmental defects characteristic of these disorders. Here, we show that although origin licensing capacity is impaired in all patient cells with mutations in origin licensing component proteins, this does not correlate with the rate of progression through S phase. Thus, the replicative capacity in MGS patient cells does not correlate with clinical manifestation. However, ORC1-deficient cells from MGS patients and siRNA-mediated depletion of origin licensing proteins also have impaired centrosome and centriole copy number. As a novel and unexpected finding, we show that they also display a striking defect in the rate of formation of primary cilia. We demonstrate that this impacts sonic hedgehog signalling in ORC1-deficient primary fibroblasts. Additionally, reduced growth factor-dependent signaling via primary cilia affects the kinetics of cell cycle progression following cell cycle exit and re-entry, highlighting an unexpected mechanism whereby origin licensing components can influence cell cycle progression. Finally, using a cell-based model, we show that defects in cilia function impair chondroinduction. Our findings raise the possibility that a reduced efficiency in forming cilia could contribute to the clinical features of MGS, particularly the bone development abnormalities, and could provide a new dimension for considering developmental impacts of licensing deficiency
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The major barriers to evidence-informed conservation policy and possible solutions
Conservation policy decisions can suffer from a lack of evidence, hindering effective decision-making. In nature conservation, studies investigating why policy is often not evidence-informed have tended to focus on Western democracies, with relatively small samples. To understand global variation and challenges better, we established a global survey aimed at identifying top barriers and solutions to the use of conservation science in policy. This obtained the views of 758 people in policy, practice, and research positions from 68 countries across six languages. Here we show that, contrary to popular belief, there is agreement between groups about how to incorporate conservation science into policy, and there is thus room for optimism. Barriers related to the low priority of conservation were considered to be important, while mainstreaming conservation was proposed as a key solution. Therefore, priorities should focus on convincing the public of the importance of conservation as an issue, which will then influence policy-makers to adopt pro-environmental long-term policies.NERC (1653183)
Grantham Foundation for the Protection of the Environment
Kenneth Miller Trust (unknown)
NERC (1653183)
NERC (NE/L002507/1)
European Commission (308454
Premolis semirufa (Walker, 1856) Envenomation, Disease Affecting Rubber Tappers of the Amazon: Searching for Caterpillar-Bristles Toxic Components
Pararama, the popular name of the larval form of the moth Premolis semirufa inhabits rubber plantations in the Amazon region and the accidental contact of the skin with the caterpillar's bristles or cocoons results in immediate and intense heat, pain, edema, and itching. In many cases a chronic inflammatory reaction with immobilization of the joints occurs. The current study has evaluated the biological and immunochemical characteristics of the Pararama caterpillar bristles extract. Electrophoretic analysis showed the presence of several components, including a very intense 82 kDa band. This latter component was endowed with intense gelatinolytic activity, as observed in zymography assays. Further analysis revealed that the extract also contained hyaluronidase activity but is devoid of phospholipase A2 activity. In vivo assays, using mice, showed that the extract was not lethal, but caused significant edema and induced intense infiltration of inflammatory cells to the envenomation site. The extract also induced high specific antibody titers, but no autoantibodies were detected. The data obtained, so far, demonstrate the existence of a mixture of different enzymes in the bristles of Premolis semirufa caterpillar, which can act together in the generation and development of the clinical manifestations of the Pararama envenomation
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