A fine-grained dark inclusion in the Vigarano CV3 chondrite: Record of accumulation processes on the meteorite parent body

Mineralogy and petrography of an unusual dark inclusion (DI) from the Vigarano CV3 chondrite (AMNH 2226-7) has been studied in detail. Formerly, this DI was briefly described by JOHNSON et al. (Geochim. Cosmochim. Acta, 54,819,1990). Unlike most common types of DIs, AMNH 2226-7 consists almost exclusively of fine grains (< μm in diameter) of mainly Fe-rich olivine and is devoid of chondrules, large mineral fragments and Fe-rich olivine aggregates (chondrule pseudomorphs). The Fe-rich olivine grains are mostly granular and equidimensional in morphology, and acicular to fibrous olivine grains, common in other types of DIs, are absent. Lesser amounts of relatively coarse grains (10-60μm) of Mg-rich olivine, Fe-rich olivine, enstatite, spinel, melilite, and perovskite are dispersed throughout the DI. A most distinguished feature of this DI is a network of arcuate bands (each 10-500μm wide and 250μm-3.5mm long) which exhibit peculiar textures. The bands consist mainly of olivine grains which are slightly finergrained and more Fe-rich than those in other areas. Several bands commonly occur roughly parallel to each other with equal spacing, forming a set of consecutive parallel bands. Different sets of parallel bands crosscut one another, some almost orthogonally. These mineralogical and textural features differ from the major group of DIs which contain chondrules and/or chondrule pseudomorphs, and indicate that the formation of AMNH 2226-7 cannot be explained by the direct replacement of a precursor chondrite. Probably, the origin of this DI is not directly related to that of the major types of DIs. We support the interpretation of JOHNSON et al. (1990) that the arcuate bands resemble fluvial sedimentary deposits and may reflect particle settling processes on the meteorite parent body. We suggest AMNH 2226-7 to be the product of reaccumulation of a fragmented and comminuted C3 chondrite. The predominant occurrence of fine-grained components in this DI may have resulted from either a grain size sorting process during reaccumulation or the disaggregation of already fine-grained precursor material such as type B DIs

Ca-Al-rich inclusions in three Antarctic CO3 chondrites, Yamato-81020, Yamato-82050 and Yamato-790992: Record of lowtemperature alteration

Ca-Al-rich inclusions (CAIs) in three Antarctic CO chondrites, Yamato (Y)-81020,Y-82050 and Y-790992 have similar overall textures; most CAIs are rimmed or concentric objects. However, there are considerable differences in mineralogy; almost all of the CAIs in Y-81020 consist of primary high-temperature phases such as melilite, anorthite, fassaite and spinel, while most of the CAIs in Y-82050 and Y-790992 contain major amounts of nepheline and lesser amounts of melilite and anorthite. CAIs in Y-790992 contain more nepheline than those in Y-82050. Small grains (<1μm in diameter) of troilite commonly coexist with nepheline. Spinel in Y-81020 is almost free of Fe, while those in Y-82050 and Y-790992 contain variable amounts of Fe (6 to 60 and 42 to 65 FeAl_2O_4 mol%, respectively). The texture of CAIs suggests that nepheline and troilite are secondary alteration products formed by replacing mainly melilite and anorthite. Spinel in CAIs and olivine in amoeboid olivine aggregates probably became enriched in Fe along with the alteration. As the alteration proceeded, fassaite and spinel were also replaced by nepheline, and perovskite was replaced by ilmenite and ulvospinel. Diopside remained unaltered even in the most heavily altered inclusions. Comparison of mineralogy before and after the alteration suggests that considerable amounts of Na, Fe, S and Cl were introduced into CAIs and some amounts of Ca and Mg were lost. Based on the amounts of nepheline, the relative degrees of alteration of CAIs are as follows : Y-81020<Y-82050<Y-790992. In order to compare the relationship between alteration of CAIs and thermal metamorphism on the parent body, metamorphic grades of the three CO chondrites were petrographically determined. The results indicate that the metamorphic grade increases in the same order as that of the degree of alteration of CAIs, i. e. Y-81020<Y-82050<Y-790992. Therefore, the results raise the possibility that alteration of CAIs may be related to thermal metamorphism which occurred on the meteorite parent body, although further investigation is still needed to verify this hypothesis

A dark inclusion in the Manych LL (3.1) ordinary chondrite: A product of strong shock metamorphism

A dark inclusion (MNC-1) from the Manych LL (3.1) chondrite contains elliptical objects ("augen"; 50-500μm in long axis) embedded in a fine-grained matrix. Most augen are composed of parallel intergrowths of fine laths of Fe-rich olivine, high-Ca pyroxene, and Na-rich feldspathic glass that commonly enclose coarse grains (5-80μm in diameter) of Fe-rich olivine (Fo_). The matrix of MNC-1 consists predominantly of interlocking, granular grains (), interstitial high-Ca pyroxene and Na-rich feldspathic glass. Both the Manych host and MNC-1 have experienced strong shock metamorphism. The texture and mineralogy of MNC-1 suggest that the matrix of MNC-1 experienced shock melting, whereas the "augen" represent unmelted precursor material. Bulk major element composition of MNC-1 is generally similar to the average values for LL chondrites, except that MNC-1 is considerably depleted in S and enriched in FeO. The large S depletion may be due to volatilization during impact-induced melting. Texture and mineralogy of the augen are distinct from those of the Manych host, so MNC-1 may not be a melt dike which formed in situ in the host rock. MNC-1 appears to be a xenolith that solidified elsewhere on the LL chondrite parent body and was later incorporated to the present location

(Un-)Möglichkeit der Überwindung nationaler Grenzen. Am Beispiel einer Vergleichsstudie zu internationalen Privatschulen zweier global cities in Deutschland und Japan

In ihrem Beitrag widmet sich die Autorin methodologischen und methodischen Fragen der Grenzen und der Grenzziehung in internationalen und vergleichenden erziehungswissenschaftlichen Studien. Grenzen bzw. bislang meist nationale Grenzen stellen in der Abgrenzung und der Konstitution des Gegenstands wie auch in der Wahl des Forschungszugangs und Designs einen zentralen, jedoch häufig unhinterfragten, Einflussfaktor dar. Die Autorin beschreibt verschiedene Möglichkeiten, um einen durch nationale Grenzen limitierten Forschungsprozess zu überwinden. Dabei wird auch die spezifisch hybride Positionierung der Autorin im theoretischen Kontext der insider-outsider-Diskussion reflektiert. (DIPF/Orig.)In international comparative studies national boundaries are usually utilized to clearly define research objects, to structure research programs and to evaluate research material. While national boundaries might influence methodological areas (orientation), they can also become relevant as a form of differentiation between research objects (positioning). The paper describes two different ways in which a nationally connotated attitude in the research process can be overcome. The first way will be illustrated by using the respective terms of \u27international schools\u27, \u27global city\u27 and the concept of \u27governance\u27, which have been discussed in a comparative study led by the author of this paper. The second way of crossing national boundaries reveals itself in the same project in using a reflective process in consideration of the researcher\u27s specific hybrid positioning (Japanese/German) and discussing the concept of self and other (insider and outsider). (DIPF/Orig.

Perspective Chapter: Improving Children’s Foot Health and Shoe Education from the Foot Health Education Project

With the aim of improving the foot health of infants and school-age children, Kinjo University in Japan has established the Foot Health Education Project in 2014, under which university faculty members, students, and industrial organizations have conducted joint activities. The results of surveys on approximately 3000 children to date have shown high prevalence rates of bunionette, undeveloped foot arch, floating toes, and a paucity of wearers of right-size shoes. Under such circumstances, a follow-up survey has been conducted to examine whether changes in foot morphology can be reversed by wearing right-size shoes. The results have suggested that wearing right-size shoes facilitated the development of foot arch and improved floating toes. We plan to continue surveys and share the trends obtained from survey results and possible measures with community residents. In addition, we plan to establish scientific evidence that is useful for education and that contributes to the healthy development of children’s feet

Effects of mask fitness and worker education on the prevention of occupational dust exposure

To decrease the incidence of pneumoconiosis, we examined dust protective mask performance and its relation to pulmonary function as well as the effects of worker education on the proper wearing of masks. One hundred and seventy-eight workers from 15 factories subject to dust exposure participated in this study. All participants were interviewed to obtain relevant personal information and underwent both a mask leakage and a pulmonary function test. The mask leakage was expressed as a percentage, with under 10% leakage indicating that the dust protective mask worked efficiently. In addition, 23 workers from 2 factories were educated on how to wear masks properly. The average mask leakage was 24.3%, and 58% of workers wore ineffective masks. Though pulmonary function was almost normal, the percent vital capacity (%VC) tended to be lower depending on the mask leakage. Mask education, which was very easy and took only a short time, dramatically decreased average mask leakage from 32.1% to 10.5% (p0.001). Educating workers to wear masks properly might prevent the worsening of pulmonary function in response to dust exposure. Appropriate mask fitness by education could be useful in preventing the development of pneumoconiosis.</p

Regulation of gonadotropin secretion and puberty onset by neuromedin U

AbstractNeuromedin U (NMU), an anorexigenic peptide, was originally isolated from porcine spinal cord in 1985. As NMU is abundant in the anterior pituitary gland, we investigated the effects of NMU on gonadotropin secretion. Both NMU and its receptors, NMUR1 and NMUR2, were expressed in the pituitary gland. NMU suppressed LH and FSH releases from rat anterior pituitary cells. Moreover, NMU-deficient mice exhibit an early onset of vaginal opening. The LHβ/FSHβ ratio, which is an index of puberty onset, is high in young NMU-deficient mice. These results indicate that NMU suppresses gonadotropin secretion and regulates the onset of puberty

Cellular DBP and E4BP4 proteins are critical for determining the period length of the circadian oscillator

AbstractThe phenotypes of mice carrying clock gene mutations have been critical to understanding the mammalian clock function. However, behavior does not necessarily reflect cell-autonomous clock phenotypes, because of the hierarchical dominance of the central clock. We performed cell-based siRNA knockdown and cDNA overexpression and monitored rhythm using bioluminescent reporters of clock genes. We found that knockdown of DBP, D-box positive regulator, in our model led to a short-period phenotype, whereas overexpressing of DBP produced a long-period rhythm when compared to controls. Furthermore, knockdown and overexpressing of E4BP4, D-box negative regulator, led to an opposite effect of DBP. Our experiments demonstrated that D-box regulators play a crucial role in determining the period length of Per1 and Per2 promoter-driven circadian rhythms in Rat-1 fibroblasts

Isolation and Phenotypic Characterization of Lotus japonicus Mutants Specifically Defective in Arbuscular Mycorrhizal Formation

Several symbiotic mutants of legume plants defective in nodulation have also been shown to be mutants related to arbuscular mycorrhizal (AM) symbiosis. The origin of the AM symbiosis can be traced back to the early land plants. It has therefore been postulated that the older system of AM symbiosis was partially incorporated into the newer system of legume-rhizobium symbiosis. To unravel the genetic basis of the establishment of AM symbiosis, we screened about 34,000 plants derived from ethyl methanesulfonate (EMS)-mutagenized Lotus japonicus seeds by microscopic observation. As a result, three lines (ME778, ME966 and ME2329) were isolated as AM-specific mutants that exhibit clear AM-defective phenotypes but form normal effective root nodules with rhizobial infection. In the ME2329 mutant, AM fungi spread their hyphae into the intercellular space of the cortex and formed trunk hyphae in the cortical cells, but the development of fine branches in the arbuscules was arrested. The ME2329 mutant carried a nonsense mutation in the STR-homolog gene, implying that the line may be an str mutant in L. japonicus. On the ME778 and ME966 mutant roots, the entry of AM fungal hyphae was blocked between two adjacent epidermal cells. Occasionally, hyphal colonization accompanied by arbuscules was observed in the two mutants. The genes responsible for the ME778 and ME966 mutants were independently located on chromosome 2. These results suggest that the ME778 and ME966 lines are symbiotic mutants involved in the early stage of AM formation in L. japonicus.ArticlePLANT AND CELL PHYSIOLOGY. 55(5):928-941 (2014)journal articl

Multiple functions of precursor BDNF to CNS neurons: negative regulation of neurite growth, spine formation and cell survival

<p>Abstract</p> <p>Background</p> <p>Proneurotrophins and mature neurotrophins elicit opposite effects via the p75 neurotrophin receptor (p75^NTR) and Trk tyrosine kinase receptors, respectively; however the molecular roles of proneurotrophins in the CNS are not fully understood.</p> <p>Results</p> <p>Based on two rare single nucleotide polymorphisms (SNPs) of the <it>human brain-derived neurotrophic factor (BDNF) </it>gene, we generated R125M-, R127L- and R125M/R127L-BDNF, which have amino acid substitution(s) near the cleavage site between the pro- and mature-domain of BDNF. Western blot analyses demonstrated that these BDNF variants are poorly cleaved and result in the predominant secretion of proBDNF. Using these cleavage-resistant proBDNF (CR-proBDNF) variants, the molecular and cellular roles of proBDNF on the CNS neurons were examined. First, CR-proBDNF showed normal intracellular distribution and secretion in cultured hippocampal neurons, suggesting that inhibition of proBDNF cleavage does not affect intracellular transportation and secretion of BDNF. Second, we purified recombinant CR-proBDNF and tested its biological effects using cultured CNS neurons. Treatment with CR-proBDNF elicited apoptosis of cultured cerebellar granule neurons (CGNs), while treatment with mature BDNF (matBDNF) promoted cell survival. Third, we examined the effects of CR-proBDNF on neuronal morphology using more than 2-week cultures of basal forebrain cholinergic neurons (BFCNs) and hippocampal neurons. Interestingly, in marked contrast to the action of matBDNF, which increased the number of cholinergic fibers and hippocampal dendritic spines, CR-proBDNF dramatically reduced the number of cholinergic fibers and hippocampal dendritic spines, without affecting the survival of these neurons.</p> <p>Conclusion</p> <p>These results suggest that proBDNF has distinct functions in different populations of CNS neurons and might be responsible for specific physiological cellular processes in the brain.</p