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排序方式: 共有334条查询结果,搜索用时 0 毫秒
61.
RW Snow CS Molyneux PA Warn J Omumbo CG Nevill S Gupta K Marsh 《Canadian Metallurgical Quarterly》1996,55(2):144-149
Repeated cross-sectional surveys among infants sleeping under insecticide-treated bed nets (ITBN) and contemporary control infants were used to estimate changes in Plasmodium falciparum exposure due to ITBN use on the Kenyan coast. Presence of P. falciparum parasites or total P. falciparum Immunoglobulin M (IgM) seropositivity were used independently and in combination in a constant risk catalytic conversion model to estimate the force of infection in ITBN and control communities. Such studies during infancy avoid problems of early saturation of prevalence due to high forces of infection and persistence of infection, minimize problems of self-treatment, and can be conducted among large populations covering a wide geographic area. These contrast previous parasitologic studies of ITBN among older children and the traditional entomologic studies of transmission that are logistically demanding. Our investigations demonstrated that parasite prevalence, IgM seropositivity, and the force of transmission were all significantly reduced by 50%. In addition, more infants under ITBN entered their second year of life without previous exposure to P. falciparum than control infants. These effects upon delayed acquisition of effective immunity require careful monitoring during future vector control programs using ITBN. 相似文献
62.
ABSTRACT: : We report that porous silicon acoustic Bragg reflectors and AlN-based transducers can be successfully combined and processed in a commercial solidly mounted resonator production line. The resulting device takes advantage of the unique acoustic properties of porous silicon in order to form a monolithically integrated bulk acoustic wave resonator. 相似文献
63.
Arunachalam K Maccarini P De Luca V Tognolatti P Bardati F Snow B Stauffer P 《IEEE transactions on bio-medical engineering》2011,58(6):1629-1636
Microwave (MW) radiometry is proposed for passive monitoring of kidney temperature to detect vesicoureteral reflux (VUR) of urine that is externally heated by a MW hyperthermia device and thereafter reflows from the bladder to kidneys during reflux. Here, we characterize in tissue-mimicking phantoms the performance of a 1.375 GHz radiometry system connected to an electromagnetically (EM) shielded microstrip log spiral antenna optimized for VUR detection. Phantom EM properties are characterized using a coaxial dielectric probe and network analyzer (NA). Power reflection and receive patterns of the antenna are measured in layered tissue phantom. Receiver spectral measurements are used to assess EM shielding provided by a metal cup surrounding the antenna. Radiometer and fiberoptic temperature data are recorded for varying volumes (10-30 mL) and temperaturesg (40-46°C) of the urine phantom at 35 mm depth surrounded by 36.5°C muscle phantom. Directional receive pattern with about 5% power spectral density at 35 mm target depth and better than -10 dB return loss from tissue load are measured for the antenna. Antenna measurements demonstrate no deterioration in power reception and effective EM shielding in the presence of the metal cup. Radiometry power measurements are in excellent agreement with the temperature of the kidney phantom. Laboratory testing of the radiometry system in temperature-controlled phantoms supports the feasibility of passive kidney thermometry for VUR detection. 相似文献
64.
McMinn Mark R.; Hathaway William L.; Woods Scott W.; Snow Kimberly N. 《Canadian Metallurgical Quarterly》2009,1(1):3
What do American Psychological Association (APA) leaders have to say about the new journal Psychology of Religion and Spirituality? A survey was sent to 204 current APA council representatives and divisional residents, yielding 63 completed questionnaires (31% response rate). Respondents generally affirmed the importance of religion and spirituality as topics of inquiry in psychology. Although not highly religious themselves, respondents recognize religion and spirituality as important aspects of human diversity. In considering the new journal, current APA leaders who responded to the survey are particularly interested in articles relating religion and spirituality to health and coping and articles considering cross-cultural and interfaith issues. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
65.
ONVisor: Towards a scalable and flexible SDN‐based network virtualization platform on ONOS 下载免费PDF全文
Yoonseon Han Thomas Vachuska Ali Al‐Shabibi Jian Li Huibai Huang William Snow James Won‐Ki Hong 《International Journal of Network Management》2018,28(2)
Network virtualization (NV) technologies have attracted a lot of attention as an essential solution for future networking infrastructure. The NV enables multiple tenants to share the same physical infrastructure and to create independent virtual networks (VNs) by decoupling the physical network in terms of topology, address, and control functions. One feasible way to realize full NV involves considering solutions based on the software‐defined networking (SDN) paradigm using its programmability. The SDN contributes many benefits to both network operations and management including programmability, agility, elasticity, and flexibility. There are several SDN‐based NV solutions; however, they suffered from a lack of scalability, high availability. Also, they have high latency between control and data plane because of proxy‐based architecture. In this thesis, we introduce a new NV platform, named Open Network Hypervisor (ONVisor). The design objectives include, among the features, (1) multitenancy, (2) scalability, (3) flexibility, (4) isolated VNs, and (5) VN federation. ONVisor was designed and implemented by extending Open Network Operating System, an open‐source SDN controller. The main features of ONVisor are (1) isolated control and data plane per VN, (2) support of distributed operations, (3) extensible translators, (4) on‐platform VN application development and execution, and (5) support of heterogenous SDN data‐plane implementations. Several experiments are conducted on various test scenarios in different test environments in terms of control and data plane performance compared to nonvirtualized SDN network. The results show that ONVisor can provide VNs a little bit lower control plane performance and similar data plane performance. 相似文献
66.
Surveyed 144 clinicians (mean age 42.7 yrs) who evaluate and treat child referral cases to examine whether Ss who define themselves primarily as individually vs family oriented actually differ significantly in their therapeutic practices. 18 Ss were identified as advocating the individual child-oriented approach over the family-oriented approach, 74 Ss advocated the use of both approaches, and 52 Ss advocated a family-oriented approach. It was found that Ss who preferred the individual and combined approaches showed a preference to approach evaluation by first seeing the parents and then shifting to the identified child. Family-oriented Ss preferred an approach that focused on seeing all family members conjointly throughout treatment. Also, individual-oriented Ss showed a greater use of tools that are more closely associated with psychodynamic theory and allow for individual play: projective testing, doll or puppet play, and craft projects. The family-oriented group used more action-oriented, interpersonally focused tools, such as behavioral contracting and assigning tasks. The individual-oriented group rated psychodynamic models as significantly more useful, while the family-oriented group rated family systems models as significantly more useful. (9 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
67.
ML Schwartz F Carruth MA Binns C Brandys R Moulton WG Snow DT Stuss 《Canadian Metallurgical Quarterly》1998,25(2):108-116
In November 1996, word reached the University of Washington that Philip Fialkow and his wife, Helen, had died while trekking in Nepal. Over a 30-year period, Dr Fialkow and his colleagues used the cellular mosaicism resulting from X-chromosome inactivation in females as a marker system to investigate the clonal development of human hematopoietic disorders. This review discusses the impact that these studies have had on our understanding of hematopoietic stem cell relationships and the pathogenesis of human neoplasia in general. To appreciate the special role played by studies on clonality, it is necessary to consider how little was known about the origin of leukemias and myeloproliferative disorders and the limited techniques available for their study in the early to mid 1960s. Dr Fialkow and his coworkers were the first to show that myeloproliferative disorders and acute myelogenous leukemias (AML) are clonal diseases at the time of diagnosis and to elucidate the level of differentiation manifested by the originating cell type. Although the myelodysplastic disorders were found to involve a pluripotent stem cell, heterogeneity was found in the level of stem cell involvement in AML. Evidence was obtained to support a multistep pathogenesis of these diseases as well as a clonal but cytogenetically normal stage in some cases of Ph-positive chronic myelogenous leukemia, AML, acute lymphoblastic leukemia and myelodysplasia. 相似文献
68.
GM Castillo C Ngo J Cummings TN Wight AD Snow 《Canadian Metallurgical Quarterly》1997,69(6):2452-2465
Perlecan is a specific heparan sulfate proteoglycan that accumulates in the fibrillar beta-amyloid (A beta) deposits of Alzheimer's disease. Perlecan purified from the Engelbreth-Holm-Swarm tumor was used to define perlecan's interactions with A beta and its effects on A beta fibril formation. Using a solid-phase binding immunoassay, freshly solubilized full-length A beta peptides bound immobilized perlecan at two sites, representing both high-affinity [K(D) = approximately 5.8 x 10(-11) M for A beta (1-40); K(D) = approximately 6.5 x 10(-12) M for A beta (1-42)] and lower-affinity [K(D) = 3.5 x 10(-8) M for A beta (1-40); K(D) = 4.3 x 10(-8) M for A beta (1-42)] interactions. An increase in the binding capacity of A beta (1-40) to perlecan correlated with an increase in A beta amyloid fibril formation during a 1-week incubation period. The high-capacity binding of A beta (1-40) to perlecan was similarly observed using perlecan heparan sulfate glycosaminoglycans and was completely abolished by heparin, but not by chondroitin-4-sulfate. Using a thioflavin T fluorometry assay, perlecan accelerated the rate of A beta (1-40) amyloid fibril formation, causing a significant increase in A beta fibril assembly over a 2-week incubation period at 1 h (2.8-fold increase), 1 day (3.6-fold increase), and 3 days (2.8-fold increase) in comparison with A beta (1-40) alone. Perlecan also initially accelerated the formation of A beta (1-42) fibrils within 1 h and maintained significantly higher levels of A beta (1-42) thioflavin T fluorescence throughout a 2-week experimental period in comparison with A beta (1-42) alone, suggesting perlecan's ability to maintain amyloid fibril stability. Perlecan's effects on A beta (1-40) fibril formation and maintenance of A beta (1-42) fibril stability occurred in a dose-dependent manner and was also mediated primarily by perlecan's glycosaminoglycan chains. Perlecan was the most effective enhancer and accelerator of A beta fibril formation when compared directly with other amyloid plaque components, including apolipoprotein E, alpha1-antichymotrypsin, P component, C1q, and C3. This study, therefore, demonstrates that perlecan not only binds to the predominant isoforms of A beta, but also accelerates A beta fibril formation and stabilizes amyloid fibrils once formed, confirming pivotal roles for perlecan in the pathogenesis of A beta amyloidosis in Alzheimer's disease. 相似文献
69.
Presents an obituary of P. Sears, a national expert on child development, known particularly for her research on self-esteem and motivation in school children. She also conducted the study of career and life satisfaction among intellectually gifted women, as part of the longitudinal study of gifted children begun by L. Terman at Stanford in 1922. Fine served as president of the Division of Developmental Psychology of the American Psychological Association in 1959 and authored or coauthored more than 30 monographs, scientific journal articles, and other research publications. (0 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
70.