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31.
The hippocampal formation (HF) of food‐storing birds is larger than non‐storing species, and the size of the HF in food‐storing Black‐Capped Chickadees (Poecile atricapillus) varies seasonally. We examined whether the volume of the septum, a medial forebrain structure that shares reciprocal connections with the HF, demonstrates the same species and seasonal variation as has been shown in the HF. We compared septum volume in three parid species; non‐storing Blue Tits (Parus caeruleus) and Great Tits (Parus major), and food‐storing Black‐Capped Chickadees. We found the relative septum volume to be larger in chickadees than in the non‐storing species. We also compared septum and nucleus of the diagonal band (NDB) volume of Black‐Capped Chickadees at different times of the year. We found that the relative septum volume varies seasonally in food‐storing birds. The volume of the NDB does not vary seasonally. Due to the observed species and seasonal variation, the septum, like the hippocampal formation of food‐storing birds, may be specialized for some aspects of food‐storing and spatial memory. © 2002 Wiley Periodicals, Inc. J Neurobiol 51: 215–222, 2002  相似文献   
32.
Activity-based protein profiling represents a powerful methodology to probe the activity state of enzymes under various physiological conditions. Here we present the development of a para-nitrophenol phosphonate activity-based probe with structural similarities to the potent agrochemical paraoxon. We demonstrate that this probes labels distinct serine hydrolases with the carboxylesterase CXE12 as the predominant target in Arabidopsis thaliana. The designed probe features a distinct labeling pattern and therefore represents a promising chemical tool to investigate physiological roles of selected serine hydrolases such as CXE12 in plant biology.  相似文献   
33.
Development and Phase 3 testing of the most advanced malaria vaccine, RTS,S/AS01, indicates that malaria vaccine R&D is moving into a new phase. Field trials of several research malaria vaccines have also confirmed that it is possible to impact the host-parasite relationship through vaccine-induced immune responses to multiple antigenic targets using different platforms. Other approaches have been appropriately tested but turned out to be disappointing after clinical evaluation. As the malaria community considers the potential role of a first-generation malaria vaccine in malaria control efforts, it is an apposite time to carefully document terminated and ongoing malaria vaccine research projects so that lessons learned can be applied to increase the chances of success for second-generation malaria vaccines over the next 10 years. The most comprehensive resource of malaria vaccine projects is a spreadsheet compiled by WHO thanks to the input from funding agencies, sponsors and investigators worldwide. This spreadsheet, available from WHO's website, is known as "the rainbow table". By summarizing the published and some unpublished information available for each project on the rainbow table, the most comprehensive review of malaria vaccine projects to be published in the last several years is provided below.  相似文献   
34.
Abstract: Analysis of the cell-free translation products of polysomes isolated from fetal brain and other organs indicates that elevation of maternal body temperature induces the synthesis of a heat shock protein of molecular weight 74,000 (74K). The newborn mammal is particularly sensitive to induction of the 74K protein. As early postnatal development proceeds, higher body temperatures are required to induce synthesis of the 74K heat shock protein.  相似文献   
35.
Making the grade     
C. J. Brown 《CMAJ》1998,159(9):1078
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37.
False Images     
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38.
Studies in animals and tissue culture have shown the importance of prolactin and growth hormone in regulating renal 1 alpha-hydroxylase activity and plasma concentrations of 1,25-dihydroxycholecalciferol (1,25(OH)2D3). Evidence for a similar role for these hormones in man was sought by using a radioreceptor assay to measure plasma 1,25(OH)2D3 concentrations in 20 normal subjects, 12 patients receiving dialysis, 11 patients with primary hyperparathyroidism, 10 pregnant women, seven women with prolactinoma, and 14 patients with acromegaly. Circulating 1,25(OH)2D3 concentrations were appreciably raised in the patients with primary hyperparathyroidism and the pregnant women (P less than 0.001), slightly but significantly increased in the patients with prolactinoma (P less than 0.05), and greatly raised in those with acromegaly (P less than 0.001). These results suggest that prolactin and growth hormone are important regulators of renal vitamin D metabolism in the physiological conditions of pregnancy, lactation, and growth in man.  相似文献   
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Recent development of screen-like bonded weaves of titanium wire for orthopaedic implant anchorage affords a unique opportunity for analytic studies of porous ingrowth micromechanics. The regular geometry of individual wires and the periodicity of the mesh weave are exploited in a series of two-dimensional finite element models, mapping interstitial bone stress fields as a function of ingrowth depth and wire size, shape, and spacing.

When the depth of bone ingrowth was less than one wire diameter, peak bone stresses always occurred at the leading (i.e. deepest) edge of bone ingrowth, immediately adjacent to the wire. As ingrowth depth approached a full wire diameter, peak local bone stresses were 2–9 times the nominal applied host bone stress, with greater stresses occurring for lower screen weave densities. Within multiple screen layers, the top layer consistently experienced the peak stress and transmitted most of the applied load, regardless of the number of underlying screen layers surrounded by bone. Neither wire size variations nor partial wire flattening substantially affected general trends in stress predictions.  相似文献   

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