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101.
The carved stele known as the “head of the tribe”, attributed to the Chalcolithic, erected at an altitude of 2290 m in the chaos of blocks in the Merveilles torrent in the Mont Bego region at Tende, was removed from its original standing place. Earth extracted from under the stele and sieved yielded a sickle blade in very fine and homogeneous Bedoulian pale biege translucid flint, pressure flaked on a heated core. The blade bears a light polish caused by cereal harvesting. This sickle blade is similar to those widely used in the southern Chassey culture (4300 to 3000 years before our era) but also sometimes in the Campaniform culture, during the ancient and middle Bronze age, like in Murée cave, in the Verdon gorges. The location of the sickle blade at the foot of the carved stele, known as the “head of the tribe”, is not just coincidental. It is highly probable that the blade was intentionally placed beside this rock. It is seemingly during a ritual ceremony that this sickle blade, probably still inserted in a wooden handle, was intentionally placed, in a propitious gesture or as an offering, beside the stele known as the “head of the tribe”. 相似文献
102.
Bone histology is an important tool for uncovering life history traits of extinct animals, particularly those that lack modern analogs, such as the non-avian dinosaurs. In most studies, histological analyses preferentially focus on long bones for understanding growth rates and determining age. Here we show, by analyzing ornithischians (a stegosaur and an ornithopod), saurischians (a sauropod and a theropod), and a crocodile, rib histology is a suitable alternative. The estimated age for all sampled taxa ranges between 14 to 17 years for Lourinhanosaurus antunesi and 27 to 31 years estimated for Draconyx loureiroi. The theropod Baryonyx was skeletally mature around 23–25 years of age but showed unfused neurocentral sutures, a paedomorphic feature possibly related to aquatic locomotion. Our results show that ribs can contain a nearly complete growth record, and reveal important information about individual age, point of sexual maturity, and, in some cases, sex. Because ribs are more available than long bones, this method opens new possibilities for studying rare and incomplete fossils, including holotypes. 相似文献
103.
《L'Anthropologie》2018,122(3):469-491
The results of an archeozoological and taphonomical analysis of mammoth ivory statuettes from gravettian levels of the grotte du Pape at Brassempouy (Landes) are presented in this article. 相似文献
104.
105.
R.W. Payne 《The Annals of applied biology》2014,164(1):11-17
The collaborations between statisticians and biologists during the 100 years since AAB was founded have led to a very impressive list of statistical techniques, whose use now goes well beyond agriculture and biology. One example is the maximum likelihood methodology for probit analysis, arising from the collaboration between Sir Ronald Fisher and Chester Bliss. Others include analysis of variance, design of experiments, generalized linear models and the residual, or restricted, maximum likelihood (REML) algorithm for fitting unbalanced linear mixed models. 相似文献
106.
Nick Bowman Dong Liu Patrick Paczkowski Jon Chen John Rossi Sean Mackay Adrian Bot Jing Zhou 《Proteomics》2020,20(13)
Highly multiplexed single‐cell functional proteomics has emerged as one of the next‐generation toolkits for a deeper understanding of functional heterogeneity in cell. Different from the conventional population‐based bulk and single‐cell RNA‐Seq assays, the microchip‐based proteomics at the single‐cell resolution enables a unique identification of highly polyfunctional cell subsets that co‐secrete many proteins from live single cells and most importantly correlate with patient response to a therapy. The 32‐plex IsoCode chip technology has defined a polyfunctional strength index (PSI) of pre‐infusion anti‐CD19 chimeric antigen receptor (CAR)‐T products, that is significantly associated with patient response to the CAR‐T cell therapy. To complement the clinical relevance of the PSI, a comprehensive visualization toolkit of 3D uniform manifold approximation and projection (UMAP) and t‐distributed stochastic neighbor embedding (t‐SNE) in a proteomic analysis pipeline is developed, providing more advanced analytical algorithms for more intuitive data visualizations. The UMAP and t‐SNE of anti‐CD19 CAR‐T products reveal distinct cytokine profiles between nonresponders and responders and demonstrate a marked upregulation of antitumor‐associated cytokine signatures in CAR‐T cells from responding patients. Using this powerful while user‐friendly analytical tool, the multi‐dimensional single‐cell data can be dissected from complex immune responses and uncover underlying mechanisms, which can promote correlative biomarker discovery, improved bioprocessing, and personalized treatment development. 相似文献
107.
Summary The distribution of -tubulin throughout cell division is studied in several taxa of higher plants. -Tubulin is present along the whole length of microtubules (Mts) in every cell stage-specific Mt array such as the preprophase band, the preprophase-prophase perinuclear Mts, the kinetochore Mt bundles, the phragmoplast, and the telophase-interphase transition Mt arrays. -Tubulin follows with precision the Mt pattern, being absent from any other, Mt-free, cell site. In cells treated with anti-Mt drugs, -tubulin is present only on degrading or on reappearing Mt arrays, while it is totally absent from cells devoid of Mts. -Tubulin is also present in tubulin paracrystals, which are formed in colchicine-treated cells. These observations support the view that in higher plants -tubulin may not be a microtubule-organizing-center-specific protein, but it may play a certain structural and/or functional role being related to - and -tubulin.Abbreviations Mt
microtubule
- MTOC
microtubule-organizing center
- PPB
preprophase band 相似文献
108.
The behaviour of a highly purified -l-fucosidase (E.C. 3.2.1.51) extracted from octopus hepatopancreas was studied with phospholipid vesicles composed of phosphatidylcholine (PC) and phosphatidylserine (PS) containing the fucosylated ganglioside FucGM1, a potential natural substrate of the enzyme. The substrate recognition and hydrolysis take place only with PS/FucGM1 mixtures via an association process of the enzyme with the vesicles at acidic pH; the enzyme rapidly and stably binds to PS vesicles but not to PC vesicles. The data suggest that only the PS-associated enzyme is able to hydrolyse FucGM1 embedded in the same bilayer. The enzyme association with FucGM1/PS vesicles is a prerequisite for ganglioside hydrolysis but is followed by irreversible enzyme inactivation. 相似文献
109.
In vitro induction and expression of interleukin 2 receptor in a clonal T helper cell differentiation model 总被引:1,自引:0,他引:1
Induction and expression of interleukin 2 (IL 2) receptor have been studied using a poly( Glu60 Ala30 Tyr10 ) (GAT)-specific T cell clone of mouse origin. This clone (52-3) has been characterized and it exhibits functional properties of T helper (TH) cells: it leads to a specific anti-DNP response in the presence of DNP-GAT and DNP-primed B cells and it secretes biological activities which can induce polyclonal B cell proliferation and IgM secretion. In vitro this clone mimics the activation stages of normal T lymphocytes and can be obtained under two states of differentiation. depending on the antigen-specific signal provided by antigen-presenting cells (APC). The expression of IL 2 receptor by this clone has been studied by (i) its response to IL 2, (ii) its capacity to absorb IL 2 bioactivity, and (iii) its reactivity with monoclonal antibody 7D4 specific for mouse IL 2 receptor. All the results indicate that the unstimulated state does not express the IL 2 receptor while the activated state does. Clone 52-3 has been compared with clone 14-1.6 that derives from a TH cell line and expresses the IL 2 receptor constitutively. 52-3 offers a good experimental model for studying in vitro, in a clonal TH cell population, the detailed mechanism of IL 2 receptor induction. 相似文献
110.
Kelder B Mukeji P Kirchner S Hovanec G Leonard AE Chuang LT Kopchick JJ Huang YS 《Molecular and cellular biochemistry》2001,219(1-2):7-11
Long-chain polyunsaturated fatty acids (LC-PUFA) are important components of cellular structure and function. Most of LC-PUFA are derived from linoleic acid and a-linolenic acid. In plants and fungi, these two acids can be synthesized from oleic acid via the action of two enzymes, 12 and 15-desaturases. Due to lack of these enzymatic activities and the ability to synthesize these two essential fatty acids, animals must obtain them from the diet. In this report, we demonstrated the expression of a fungal 12-desaturase gene in mouse L cells incubated in serum-free medium. The results showed a significant increase in the amount of linoleic acid with a concomitant decrease of oleic acid in cellular lipids. Most of the newly formed linoleic acid was incorporated into cellular phospholipids, particularly phosphatidylcholine. The increase of linoleic acid provided the substrate for the endogenous synthesis of (n-6) LC-PUFA, such as eicosadienoic acid (EDA), dihomo--linoleic acid (DGLA) and arachidonic acid (AA). Prolonged incubation further increased the levels of linoleic acid derived from oleic acid by the action of 12-desaturase, and the levels of 20:2n-6 produced from linoleic acid by the action of the endogenous elongase. However, prolonged incubation suppressed significantly the formation of DGLA and AA. In a separate study, a fungal 6-desaturase gene has also been expressed in the mouse L cells incubated in serum-containing medium. The result shows a significant increase in levels of 20:3n-6 and 20:4n-6. These findings demonstrate that through genetic modification, it is possible to (1) generate cell lines which no longer require dietary 'essential' fatty acids and (2) alter the endogenous fatty acid metabolism to enhance the production of LC-PUFA and their derivatives. 相似文献