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81.
Normal enteric nervous system (ENS) development relies on numerous factors, including appropriate migration, proliferation, differentiation, and maturation of neural crest (NC) derivatives. Incomplete rostral to caudal migration of enteric neural crest-derived progenitors (ENPs) down the gut is at least partially responsible for the absence of enteric ganglia that is a hallmark feature of Hirschsprung disease (HSCR). The thought that ganglia proximal to aganglionosis are normal has guided surgical procedures for HSCR patients. However, chronic gastrointestinal dysfunction suffered by a subset of patients after surgery as well as studies in HSCR mouse models suggest that aberrant NC segregation and differentiation may be occurring in ganglionated regions of the intestine. Studies in mouse models that possess enteric ganglia throughout the length of the intestine (non-HSCR) have also found that certain genetic alterations affect neural crest lineage balance and interestingly many of these mutants also have functional gastrointestinal (GI) defects. It is possible that many GI disorders can be explained in part by imbalances in NC-derived lineages. Here we review studies evaluating ENS defects in HSCR and non-HSCR mouse models, concluding with clinical implications while highlighting areas requiring further study. 相似文献
82.
In what ways are care and compassion implicated in efforts to establish lives worth living? Drawing on fieldwork in a Danish Neonatal Intensive Care Unit (NICU), in this article we investigate the role of family biographies in conducting life-and-death decisions around premature infants. Guided by a larger literature on citizenship, we view decisions in the NICU as political acts of assigning citizenship. We ask what bodies and biographies can generate and evoke care and compassion among NICU staff and forge entries or exits from the Danish Welfare State. We demonstrate that infants’ origin stories are appointed legitimate forms of suffering in contemporary Danish society and are thus granted an unnoticed form of authority in life-and-death decisions. In this way, we conclude that what comes to constitute a life worth living in the twenty-first-century Danish Welfare State is in fact the worth of the family. 相似文献
83.
Djamila Schans 《Ethnic and racial studies》2013,36(7):1164-1182
Inspired by recent efforts in the United States to quantify the degree of transnational ties that immigrants possess, this article explores and analyses the prevalence and determinants of transnational family ties of immigrants in the Netherlands. Using data from a representative survey of four immigrant groups in the Netherlands, this paper also aims to fill the gap in knowledge regarding the effects of incorporation into an immigrant's host society on transnational family ties. Findings show that, while the vast majority of immigrants with relatives in the country of origin have frequent contact with these relatives, only a third of respondents contribute to the livelihood of family members in the homeland. Incorporation characteristics show distinct patterns over different types of involvement. While incorporation variables have a negative effect on the frequency of contact, they show little effect on remittances. 相似文献
84.
Angie K. Beeman 《Ethnic and racial studies》2013,36(5):687-712
The purpose of this article is to empirically demonstrate a concept, known as “emotional segregation” through a systematic analysis of US films. Emotional segregation is defined as an institutionalized process, whereby European Americans are unable to see people of colour as emotional equals or as capable of sharing the same human emotions and experiences. This concept was inspired by Charles C. Stember's (1976) study of sexual racism and Patricia Hill Collins’ (2000) work on sexualized racism. In order to examine the existence of emotional segregation in the United States, a content analysis was conducted of forty US films chosen from a stratified random sample. Differences were found in media portrayals of inter- and intra-racial relationships involving African Americans. Future research on emotional segregation is suggested to assess how this phenomenon creates emotional barriers among ethnic groups. 相似文献
85.
Susan Eckstein 《Ethnic and racial studies》2013,36(9):1648-1667
Social capital takes on distinctive meaning in the context of large-scale immigration from poor to rich countries. In this article, characteristics of social capital embedded in transnational networks and norms, conditions conducive to the formation of such networks, and effects such networks have are extrapolated from an analysis of how and why cross-border relations among Cuban-Americans and Cubans in their homeland have changed since the 1959 Castro-led revolution. The transnational social capital generating benefit on which the study focuses is remittances. Remittances are of growing global importance to less developed countries, and in some countries they generate more revenue than foreign aid and foreign investment. The analysis addresses a range of unintended as well as intended consequences remittances may have. 相似文献
86.
Peter Zwick 《水生昆虫》2013,35(1):13-22
Larval structures diagnostic of several Plecoptera families, subfamilies or genera are described and illustrated. They concern the following: distinction of larval Leuctridae from Capniidae; an additional apomorphy of Nemouridae; a synapomorphy of Perlidae and Perlodidae; monophyly of each of the two subfamilies of Chloroperlidae, and the generic limits among Chloroperlidae: Paraperlinae. Paraperla lepnevae Zhiltzova is transferred to Utaperla. Some comments on Notonemouridae are included. 相似文献
87.
Jiro Yamada 《Bioscience, biotechnology, and biochemistry》2013,77(4):1013-1015
The interaction of some anthracycline antibiotics (adriamycin, daunomycin, aclacinomycin-A) with bacteriophage ?X174 was investigated. Adriamycin and daunomycin inactivated the infectivity of both free ?X174 phage and naked single-stranded ?X174 DNA without DNA strand scission, but aclacinomycin-A did not show this action. The phage inactivation reaction was reversibly inhibited by Superoxide dismutase, catalase or other oxygen radical scavengers. The inactivation of ?X174 by adriamycin and aclacinomycin-A was stimulated by the addition of Cu2+, while the ?X174 inactivation by daunomycin was inhibited by the addition of Cu2+. The ?X174 inactivation by adriamycin and aclacinomycin-A in the presence of Cu2+ was caused by degradation of DNA, and this inactivation reaction was inhibited irreversibly by oxygen radical scavengers. These results indicate that anthracycline antibiotics bind to ?X174 DNA in the form of free radicals and that during the auto-oxidation of these antibiotics in the presence of Cu2+, oxygen radicals were generated to cause the degradation of ?X174 DNA. 相似文献
88.
Shuichi Ishino Kazuo Yamaguchi Kunikatsu Shirahata Kazumi Araki 《Bioscience, biotechnology, and biochemistry》2013,77(10):2557-2560
To characterize aspartyl aminopeptidase from Aspergillus oryzae, the recombinant enzyme was expressed in Escherichia coli. The enzyme cleaves N-terminal acidic amino acids. About 30% activity was retained in 20% NaCl. Digestion of defatted soybean by the enzyme resulted in an increase in the glutamic acid content, suggesting that the enzyme is potentially responsible for the release of glutamic acid in soy sauce mash. 相似文献
89.
Hiromichi Nagasawa Akira Isogai Akinori Suzuki Saburo Tamura 《Bioscience, biotechnology, and biochemistry》2013,77(8):1759-1763
13C-NMR spectra of isoechinulins A, B and C, metabolites from Aspergillus ruber, were fully assigned on the basis of chemical shifts and multiplicities and comparison with their analogues. Taking advantage of the symmetrical structure of the diketopiperazine ring, the stereochemistry of the trisubstituted carbon-carbon double bond in a dehydrotryptophyl moiety was determined as Z (cis) by measuring the coupling constants, , in the proton nondecoupled spectrum of isoechinulin B. 相似文献
90.
Pseudomonas M16 is the mutant derived from a facultative methylotroph, Pseudomonas N842, which is the potent producer of coenzyme Q10 (CoQ10). This mutant with elevated productivity of CoQ10 was observed to accumulate the significant amount of another CoQ homolog, which could not be detected in the parent strain. This CoQ homolog was extracted from the intact cells of the mutant and purified to crystaline state. The chemical properties and the results of UV, NMR and mass spectrometries revealed that this CoQ homolog was CoQ11. 相似文献