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1.
Lauren Kapalka Richerme 《Arts Education Policy Review》2019,120(2):94-102
The authors of various practitioner and scholarly documents suggest markedly contrasting understandings about the nature of “policy.” These divergent conceptions raise the question: What is at stake by understanding the nature of policy in one way as opposed to another? The purpose of this philosophical inquiry is to interrogate the nature of “policy” as it relates to music education and to question the values that do and might underlie and propagate through contrasting understandings of “policy.” Subsequently, I examine two aspects of policy, problem identification and meaning-making, that have gone largely unexplored in the arts education literature.Using Foucault's writings, I argue that power-laden policy texts often have the greatest impact, not when they are mandated, but when they go misrecognized as common sense. I also advocate for the consistent use of the terms “policy texts” and “policy actions,” including as an alternative to the imbalanced designations of “soft policies” and “hard policies.” Drawing on Dewey arts educators might form “publics” around problems having consequences that they deem far-reaching, recurrent, and irreparable. Individual and collective political narratives, including what Ganz explains as “stories of self,” “stories of us,” and “stories of now,” can foster the meaningful connections necessary for forming “publics” who address pressing problems in arts education. 相似文献
2.
The Speckled Trout blastoderm at the late high blastula stage is characterized by two different cell populations. The “light” blastomeres comprise one cell type while the “dark” and “medium” blastomeres appear to differ from one another only in degree and thus may be considered as the second type. “Dark” and “medium” blastomeres are irregular in shape, are located centrally and deep in the blastoderm, have an abundance of smooth endoplasmic reticulum with associated 520 Å glycogen particles and a single mitochondrial profile. The “light” blastomeres have randomly arranged glycogen particles in minimal quantities in contrast to the “medium” and “dark” blastomeres and in addition exhibit three mitochondrial profiles, which could however represent artifacts. It is postulated that in the Speckled Trout cellular differentiation has commenced by the third day of incubation at 10°C and that this is manifested visually by the appearance of two different cell populations; the more differentiated “dark” and “medium” blastomeres possibly destined to give rise to the hypoblast and the less differentiated “light” blastomeres. 相似文献
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The categorization of individuals as “male” or “female” is based on chromosome complement and gonadal and genital phenotype. This combined genetic-gonadal-genitals sex, here referred to as 3G-sex, is internally consistent in ~99% of humans (i.e., one has either the “female” form at all levels, or the “male” form at all levels). About 1% of the human population is identified as “intersex” because of either having an intermediate form at one or more levels, or having the “male” form at some levels and the “female” form at other levels. These two types of “intersex” reflect the facts, respectively, that the different levels of 3G-sex are not completely dimorphic nor perfectly consistent. Using 3G-sex as a model to understand sex differences in other domains (e.g., brain, behavior) leads to the erroneous assumption that sex differences in these other domains are also highly dimorphic and highly consistent. But parallel lines of research have led to the conclusion that sex differences in the brain and in behavior, cognition, personality, and other gender characteristics are for the most part not dimorphic and not internally consistent (i.e., having one brain/gender characteristic with the “male” form is not a reliable predictor for the form of other brain/gender characteristics). Therefore although only ~1% percent of humans are 3G-“intersex”, when it comes to brain and gender, we all have an intersex gender (i.e., an array of masculine and feminine traits) and an intersex brain (a mosaic of “male” and “female” brain characteristics). 相似文献
5.
Yeonbo Jeong 《New genetics and society》2013,32(4):349-369
This paper explores how concepts of hope, motherhood, responsibility, and science are mobilized and transformed in the marketing strategies of private cord blood banks in South Korea. Cord blood banking provides a useful case study of the “political economy of hope,” which emphasizes future expectations over current utility. In particular, appeals to hope are rendered natural as being applied in relation to various concepts of motherhood (e.g. “scientific motherhood” and “consumer motherhood”), thereby refiguring ideas of a mother's responsibility to her child. In South Korea, cord blood banks rely heavily on the discourse of “scientific motherhood,” which is based on certain gender norms and ideas about science, modernity, and “advanced society.” By exploring the discourse of scientific motherhood, this study reexamines the “political economy of hope” through the lenses of gender and transnationalism. 相似文献
6.
The view according to which damselfly males practice two alternative reproductive tactics of access to females is critically discussed. It is widely accepted that some males (“territorial” ones) have priority as potential female partners, while others (“sneakers” or “wanderers”) are incapable of retaining an individual territory. They have a chance of mating only by intruding briefly into the area defended by a “territorial” male when a female is present there. Thus, the tactics of a “territorial” male consists in waiting for a female in its territory and copulating with it “by agreement,” whereas non-territorial males resort to forced copulations. By observation of individually marked males (48 out of 118) it was shown that every male could be regarded as “territorial” during a certain period and as a “wanderer” before and after it. Thus, no correlation between the modes of space use by a male (residence/mobility) and the characters of its external morphology and/or signal behavior appears to be possible in principle. According to the data obtained, a more plausible explanation is that the female chooses not the male but the best area for oviposition. In addition, it was ascertained that adherence to forced copulations cannot constitute successful “tactics” since they rarely result in insemination, neither by “territorial” nor “non-territorial” males. In other words, we are dealing not with certain alternative tactics (i.e., specialized adaptive mechanisms that have evolved in the species) but simply with the results of different sets of circumstances at a given moment. 相似文献
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《Geobios》1988,21(4):465-493
The present paper describes 12 species of fish otoliths recovered by washing and screening processes from the Deccan Trap associated sedimentary (Intertrappean) beds exposed near Rangapur, Hyderabad District, Andhra Pradesh, India. The present collection of otoliths contains four major groups: Clupeomorpha (“Clupeidarum” sp.), Osteoglossomorpha (“Osteoglossidarum” deccanensis sp. nov., “O”. intertrappus sp. nov. and “Notopteridarum” nolfi sp. nov.), Protacanthopterygii (“Salmoniformorum” rectangulus sp. nov.), and Percomorpha (Dapalis sp., “Apigonidarum” ovatus sp. nov., “Serranidarum” sp., “Percoideorum” ellipticus sp. nov., “P.” rangapurensis sp. nov., “Percoideorum” sp. 1 and “Percoideorum” sp. 2). This collection of otoliths represents freshwater lacustrine deposition of the sediments. The age of the Intertrappean beds is considered Uppermost Cretaceous to Palaeoncene on the basis of freshwater ostracode (Paracypretta jonesi, Mongolianella hislopi and Candoniella sp.) and charophyte (Platychara perlata and Nemegtichara sp.) assemblages. 相似文献
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Yunfei Jiang Rachid Lahlali Chithra Karunakaran Thomas D. Warkentin Arthur R. Davis Rosalind A. Bueckert 《Plant, cell & environment》2019,42(1):354-372
Field pea (Pisum sativum), a major grain legume crop, is autogamous and adapted to temperate climates. The objectives of this study were to investigate effects of high temperature stress on stamen chemical composition, anther dehiscence, pollen viability, pollen interactions with pistil and ovules, and ovule growth and viability. Two cultivars (“CDC Golden” and “CDC Sage”) were exposed to 24/18°C (day/night) continually or to 35/18°C for 4 or 7 days. Heat stress altered stamen chemical composition, with lipid composition of “CDC Sage” being more stable compared with “CDC Golden.” Heat stress reduced pollen viability and the proportion of ovules that received a pollen tube. After 4 days at 35°C, pollen viability in flower buds decreased in “CDC Golden,” but not in “CDC Sage.” After 7 days, partial to full failure of anthers to dehisce resulted in subnormal pollen loads on stigmas. Although growth (ovule size) of fertilized ovules was stimulated by 35°C, heat stress tended to decrease ovule viability. Pollen appears susceptible to stress, but not many grains are needed for successful fertilization. Ovule fertilization and embryos are less susceptible to heat, but further research is warranted to link the exact degree of resilience to stress intensity. 相似文献
9.
Wendy M. Laybourn 《Ethnic and racial studies》2018,41(11):2085-2103
Research on black authenticity identifies “oppressive othering” and “white standards of beauty”, particularly lighter skin tone, as key components. Few studies disentangle which of these two theoretical components matter the most for a particular outcome. Rap music, whose lyrics are often categorized as authentic expressions of blackness, offers an intriguing case to compare the effects of “oppressive othering” (as alcohol and drug lyrics) and “white standards of beauty” (as the rap artist’s skin tone) on national music charts. Analysing artists’ skin tone and lyrical content of songs ranked on Billboard Rap Year-End Charts from 2007 to 2011, results show that lighter skin tone is significantly and positively related to higher chart rankings. Alcohol and drug lyrics, however, had a non-significant effect. Implications are discussed in relation to the effects of the commodified imagery of “authentic” blackness in the new digital era of music. 相似文献
10.
上世纪70年代末以降,考古遗址中出土生物材料的稳定同位素分析,在考古学和生物考古研究领域越来越发挥重要作用,成为现代考古学研究的重要组成部分。国内外学界常将其定位为分析技术,从未从学科层面予以考虑和重视。鉴于同位素分析的重要性以及学科发展的迫切性,将其由分析技术层面上升至学科层面实属大势所趋。本文将之前的"稳定同位素分析"首次命名为"稳定同位素生物考古学"(简称为同位素生物考古学),将其列为广义概念下生物考古学的重要学科分支之一。本文详细介绍了稳定同位素生物考古学的概念、研究简史、分析原理和研究目标;在分析原理上,除已有的"我即我食"和"我非我食"之外,还首次提出了"我即我是"和"我即我居";并对今后如何深入开展研究进行了展望。 相似文献
11.
BackgroundThe essentiality of trace elements in human diets is well recognized and adequate levels are a critical component of optimal health. To date, public health efforts have focused primarily on macronutrients or trace minerals that are easily analyzed. The goal of this research is to provide assessment of the dietary standards developed for Zn, Fe, and Cu in 100+ developed, marginal, and developing countries. We summarize the current recommendations and changes from the last decade, categorize and provide scientific basis for values established, factors that affect requirements, and current global challenges.MethodsThe electronic databases of Google Scholar, PubMed, Embase, Web of Science and Cochrane Library were searched using the keywords “trace minerals,” “micronutrients, ““zinc,” “iron,” “copper,” “dietary standards” and “recommendations.” A total of 123 studies published from 1965 to 2019 were included.ResultsThe World Health Organization (WHO) has established dietary standards to address nutrient deficiencies, prevent infections and ensure basic metabolic functions; these are utilized by most developing countries. Developed countries or their alliances have established values similar to or higher than the WHO, primarily for promotion of optimal health and well-being. Transitional countries are more concerned with issues of bioavailability, food security and undernutrition. Globally, Zn and Cu recommendations are lower in women than in men; Fe requirements are higher to compensate for menstrual losses. Important considerations in establishing guidelines for these minerals include bioaccessibility, dietary practices and restrictions, food processing, interactions, and chemical forms. The global challenges of the triple burden of malnutrition, hidden hunger, increased consumption of ultra-processed foods and obesity have been associated with Zn, Fe, and Cu deficiencies.ConclusionThis research provides public policy and health professionals evidenced-based information useful for the establishment of dietary standards world-wide. 相似文献
12.
Romaine Farquet 《Ethnic and racial studies》2018,41(2):362-380
Since the end of the Kosovo War in 1999 and the “liberation” of the territory from Serbian forces, narratives about the “freedom struggle” have been crafted and defended both in Kosovo and abroad. The transmission of these memories forms part of a broader effort to create a “national” history of Kosovo and constitute an “Albanian imagined community”. This article scrutinizes the memories of the “liberation” produced by Albanian-speaking migrants who were active on behalf of their homeland in Switzerland. It explores the construction of masculinities within narratives collected via oral history interviews. In line with the literature on “nation” and gender in Kosovo, this research acknowledges the presence of two main forms of masculinity: the “heroic fighter” and the “pacifist”. However, it also demonstrates the crystallization of the “entrepreneur”, an alternative type who integrates the transnational “neoliberal” discourses and proposes a more positive image of “Albanian men” in Switzerland. 相似文献
13.
Obligate neotenic salamanders die if forced to metamorphose. We suggest that this can be explained by assuming: 1) their “excess” DNA is “junk” DNA; 2) the “adult” specifying portion of the DNA becomes junk DNA and is available for repeated duplication. This suggests a “new” junk DNA molecular clock. We obtain remarkable agreement in “predicting” the amount of DNA per nucleus in present day non-obligate neotene salamanders from this molecular clock. These observatons are consistent with the idea that the development of these animals is describable in terms of differentiation trees whose branches (gene cascades) corresponding to adult somatic tissues accumulate deleterious mutations over evolutionary time. We show that the amount of DNA per nucleus increases linearly with the phylogenetic age of salamander families. The lack of constraints by natural selection, on unused adult branches, may account for the large amount of so-called “junk DNA” in obligate neotenic salamanders. The effects of this excess DNA, via increased cell size, suggest a positive feedback, ecophysiological explanation for such junk DNA: adaptation to cool water environments is enhanced by the lower metabolism associated with more DNA, larger cells and slower developmental time. 相似文献
14.
Vladimir S. Lebedev Mikhail Yu. Rusin Elena D. Zemlemerova Vera A. Matrosova Anna A. Bannikova Yulia M. Kovalskaya Alexey S. Tesakov 《Journal of Zoological Systematics and Evolutionary Research》2019,57(3):695-709
Phylogeny of birch mice is estimated using sequences of ten nuclear genes and one mitochondrial gene. Based on the results of tree reconstructions and molecular dating, five major lineages are recognized: “tianschanica,” “concolor,” “caudata,” “betulina,” and “caucasica.” It is established that the three latter lineages constitute a clade and that the long‐tailed birch mouse Sicista caudata is the sister group of the “caucasica” lineage. The “tianschanica” lineage is placed as the sister branch to all other species, however, with insufficient support. The cytochrome b tree is generally concordant with the nuclear topology. The molecular clock results suggest that the radiation among the main lineages occurred in the Late Miocene–Early Pliocene (6.0–4.7 Mya). The correspondence between molecular dating and the fossil record is discussed. Based on nuclear data, a high level of divergence between cryptic species in the “tianschanica” lineage is confirmed. Mitochondrial and nuclear data suggest the existence of a potential cryptic species within Sicista strandi. 相似文献
15.
Cronquist (1987) criticizes cladism for its rejection of paraphyletic groups, which he would retain if he feels they are “conceptually useful.” We argue that paraphyletic higher taxa are artificial classes created by taxonomists who wish to emphasize particular characters or phenetic “gaps,” and that formal recognition of such taxa conveys a misleading picture of common ancestry and character evolution. In our view, classifications should accurately reflect the nested hierarchy of monophyletic groups that is the natural outcome of the evolutionary process. Such systems facilitate the study of evolution and provide an efficient summary of character distributions. Paraphyletic groups, such as “prokaryotes,” “green algae,” “bryophytes,” and “gymnosperms,” should be abandoned, as continued recognition of such groups will only serve to retard progress in understanding evolution. Contrary to Cronquist’s (1987) assertions, cladistic theory is not at odds with standard views on speciation and the existence of ancestors. Groups of interbreeding organisms can continue to exist after giving rise to descendant species, and there are several ways in which such groups, whether extant or extinct, can be incorporated into cladistic classification. In contrast, paraphyletic higher taxa are neither cohesive (integrated by gene flow) nor whole, do not serve as ancestors, and are unacceptable in the phylogenetic system. Fossils may be of great value in assessing phylogenetic relationships and are readily accommodated in cladistic classification. Cladistic studies are helping to answer major questions about plant evolution, and we anticipate increased efforts to develop a truly phylogenetic system. 相似文献
16.
John M. Reiner 《Journal of theoretical biology》1983,105(4):545-552
The largely unsolved problems in the theoretical analysis of differentiation and ageing involve a substantial component of linguistic (semantic) difficulties. Some of these are simple traps of ambiguity, resulting from metaphorical or analogical employment of established terms—for example, “terminal differentiation” (loss of division potential in vitro) as a borrowing from “differentiation” as used by developmental biologists, or “commitment” by analogy with “determination”. Some difficulties represent a failure to adopt (at least provisionally) an operational (empirical) view—for example, failure to ask what is the nature of the evidence for the view that a fertilized ovum is totipotential, or to scrutinize the evidence for the view that cells “terminally differentiated” in vitro in a conventional medium are in fact moribund under all conditions, or to examine more closely the view that the differentiated state and the cycling state are mutually exclusive.With respect to the problem of ageing, we review some of the critical experiments on ”terminal differentiation” or “clonal senescence”. We then proceed to consider some of the models that have been proposed, including a molecular model proposed by the author which appears to overcome some of the objections to other models. Some of the models exemplify the results of what are ultimately semantic vices.The problems with which these remarks began should indeed yield to the immense and novel resources of molecular biology. But the development of complete analyses demands not only good luck and delicate technique but also critical semantic clarity and severity. Given the best tools, we shall solve major theoretical problems only if we understand quite fully what problem it is that we are trying to solve—and the history of science illustrates that this is not as elementary a matter as it sounds. For the working scientist semantics (and indeed all philosophy of science) is not an indulgence or a frill, but a basic technical resource. 相似文献
17.
Two cell populations in sunflower root meristems are described. Most cells stop in G1 after being cultured in sucrose-deficient medium, but “leaky” cells continue through DNA synthesis and stop in G2. A comparison of “leaky” and arrested cells is reported on the basis of radiosensitivity, and cytological and biochemical responses to metabolic inhibitors. “Leaky” cells are randomly distributed throughout primary meristematic tissues. They are not inhibited from initiating DNA synthesis by exposure to doses of γ-irradiation ranging from 300–7200 R; arrested cells, depending upon the dose, are inhibited partially or completely. “Leaky” cells do, however, show a dose-dependent mitotic delay in G2, which is the same as arrested cells. Treatment with puromycin and actidione does not inhibit “leaky” cells from initiating DNA synthesis but does inhibit them from mitosis. Arrested cells are inhibited from advancing to S and M by both inhibitors. Also, puromycin and actidione cause a decrease in protein and RNA synthesis, demonstrating a possible protein dependent RNA synthesis necessary for cell cycle progression. Actinomycin D (10 μg/ml) inhibits neither “leaky” nor arrested cells from entering S and M. At 30 μg/ml, however, arrested cells are partially inhibited. “Leaky” cell metabolism is unique in preparation for and initiation of DNA synthesis but similar to that of the remaining cells of the meristem in terms of requirements for progression through the rest of the mitotic cycle. 相似文献
18.
Secondary mesenchyme cells (SMCs) of the sea urchin embryo are composed of pigment cells, blastocoelar cells, spicule tip cells, coelomic pouch cells and muscle cells. To learn how and when these five types of SMCs are specified in the veg2 descendants, Notch or Nodal signaling was blocked with γ‐secretase inhibitor or Nodal receptor inhibitor, respectively. All types of SMCs were decreased with DAPT, while sensitivity to this inhibitor varied among them. Pulse‐treatment revealed that five types of SMCs are divided into “early” (pigment cells and blastocoelar cells) and “late” (spicule tip cells, coelomic pouch cells and muscle cells) groups; the “early” group was sensitive to DAPT up to the hatching, and the “late” group was sensitive until the mesenchyme blastula stage. Judging from timing of the shift of Delta‐expressing regions, it was suggested that the “early” group and “late” groups are derived from the lower and the middle tier of veg2 descendants, respectively. Interestingly, numbers of SMCs were also altered with SB431542; blastocoelar cells, coelomic pouch cells and circum‐esophageal muscles decreased, whereas pigment cells and spicule tip cells increased in number. Pulse‐treatment showed that the “early” group was sensitive up to the mesenchyme blastula stage, while the “late” group up to the onset of gastrulation. Thus, it became clear that precursor cells of the “early” and “late” groups, which are located in different regions in the vegetal plate, receive Delta and Nodal signals at different timings, resulting in the diversification of SMCs. Based on the obtained results, the specification processes of five types of SMCs are diagrammatically presented. 相似文献
19.
Qian Li 《Palaeoworld》2018,27(4):490-505
New cricetid (Cricetops dormitor, Eocricetodon sp., Eucricetodon cf. E. wangae, Pappocricetodon schaubi) and dipodid (Allosminthus gobiensis n. sp., Allosminthus ernos, Allosminthus uniconjugatus, Allosminthus cf. A. majusculus, Primisminthus shanghenus, Sinosminthus sp.) occurrences from the “Lower Red”, “Middle Red”, “Middle White” and “Upper White” beds of the Erden Obo section in Nei Mongol, China are reported. They are first discovered in these horizons. On the basis of the comparison of the rodent assemblages, we consider that the age of the “Upper White” beds is early Oligocene, the age of the “Middle Red” and “Middle White” beds is probable more similar to the age of late Eocene Houldjin Formation and lower part of Chaijiachong Formation, and the age of the “Lower Red” beds is correlative to the Sharamurunian. The diversity of ctenodactyloid, dipodid, and cricetid appears to change, and the turnover in rodent fauna possibly responded to the environmental and climate change towards the end of middle Eocene. 相似文献
20.
Cyanide content of cassava (Manihot esculenta,Euphorbiaceae) cultivars used by Tukanoan Indians in Northwest Amazonia 总被引:1,自引:0,他引:1
Darna L. Dufour 《Economic botany》1988,42(2):255-266
Cassava (Manihot esculenta) is a cyanide-containing food crop used by many indigenous peoples in Amazonia. Tukanoan Indians in Northwest Amazonia utilize both “bitter” and “sweet” cassava cultivars. Those classified as “bitter” are the dietary staple. Analysis of 13 commonly used “bitter” cultivars indicates that they are high in cyanide in comparison to values reportedin the literature. The Tukanoan practice of including the inner peel in the edible portion contributes to the high cyanide values found. 相似文献