•Mechanical properties of rice kernels on dorsal side were different with ventral side.•Breaking force and strength on ventral side were lower than those on dorsal side.•Rice fissure appearing ...originally on ventral side was related to breaking strength.•Milling quality was related to the breaking force and strength difference.
Three-point bending tests on both ventral and dorsal sides of brown rice kernels were conducted to determine relationship between head rice yield and mechanical properties. Kernel breaking force on ventral side was lower than that on dorsal side. The same result was also revealed in the breaking strength and the elastics modulus. Frequency distribution of the kernel-to-kernel breaking force of ventral side was significantly different from that of the dorsal side. The breaking force difference between the ventral side and the dorsal side increased with increase in the average breaking force. It was found that rice milling quality index not only was related linearly with the breaking force on both the ventral and the dorsal sides, but also related to the breaking strength difference between the two sides. The head rice yield increased with the increase in the break force difference between the ventral side and the dorsal side.
Chromite is one of the earliest crystallized minerals from mafic melts and has been used as an important "petrogenetic indicator." Its composition may be modified by interaction with intercumulate ...melt and adjacent minerals. Thus, chromite in mafic-ultramafic rocks contains clues to the geochemical affinity, evolution, and mantle source of its parent magmas. The Devonian Xiarihamu intrusion, located in the East Kunlun Orogenic Belt in the northern Tibet Plateau, China, hosts a very large disseminated Ni-Co sulfide deposit. This study focuses on geochemistry of the chromite enclosed in olivine of ultramafic rocks of the intrusion. Enrichments in Mg and Al in the rim of the chromite indicate only minor effects of alteration on the compositions of the chromite. The chromites enclosed in the olivines with forsterite percentage (Fo) lower than 87 are characterized by large variations in major and trace elements, such as large ranges of Cr·100/(Cr+Al) (Cr#=15-47), Mg·100/(Mg+Fe2+) (Mg#=41-65), and Al2O3 (=26-53 wt%) as well as 380-3100 ppm V, 70-380 ppm Ga, and 1100-16300 ppm Zn. The chromites display positive correlations between Cr/(Cr+Al) and Ti, Mn, V, Ga, and Sc, inconsistent with fractional crystallization but indicative of an interaction between the chromites, intercumulate melts and hosting minerals. In contrast, chromites hosted in olivine with Fo>87 in harzburgite have small variations in Cr# (ranging from 37 to 41), Mg# (48 to 51), and Al2O3 (30 to 35 wt%) as well as restricted variation in trace elements, indicating relatively weak interaction with trapped liquid and adjacent phases; these compositions are close to those of the most primitive, earliest crystallized chromites. The most primitive chromite has similarities with chromite in mid-ocean ridge basalt (MORB) in TiO2 and Al2O3 contents (0.19-0.32 and 27.9-36.3 wt%, respectively) and depletion of Sc and enrichment of Ga and Zn relative to MORB chromite. The geochemistry of the chromite indicates a partial melting of the asthenospheric mantle that was modified by melts derived from the subduction slab at garnet-stable pressures.
Abstract
To characterize the integrated magmatic processes for magma plumbing systems from mantle sources to magma chambers, we present Mg–Sr–Nd isotopic data for a representative mafic–ultramafic ...intrusion in Xiarihamu, northern Tibetan Plateau, China. The intrusion hosts the largest magmatic Ni–Cu sulfide deposit in an orogenic setting in the world and is composed predominantly of harzburgite, orthopyroxenite, websterite, and gabbronorite. The cumulate harzburgites have relatively low δ26Mg of orthopyroxene (–0·49 to –0·34‰) and moderately high (87Sr/86Sr)i and positive εNd(t) values (0·7067–0·7080 and +0·4 to +1·8, respectively). Most of the orthopyroxenites, websterites, and gabbronorites have slightly higher δ26Mg of orthopyroxene (–0·34 to –0·21‰) and higher (87Sr/86Sr)i and lower εNd(t) values (0·7087–0·7118 and –4·0 to –1·4, respectively) than the harzburgites. On the other hand, marginal facies (i.e. a few centimeters to meters from the contact between the intrusion and country rocks of schist, gneiss, and marble) including websterite and gabbronorite are marked by low δ26Mg of orthopyroxene (–0·44 to –0·33‰) and extremely high (87Sr/86Sr)i and negative εNd(t) values (0·7127–0·7172 and –5·4 to –4·8, respectively). The relatively low δ26Mg, moderately high (87Sr/86Sr)i, and positive εNd(t) of the harzburgites are best interpreted by inheritance from the mantle source, which was previously metasomatized by subducted Mg-rich carbonates. Given the fact that the solidus of carbonated mantle is significantly lower than that of volatile-free mantle, mantle metasomatism by carbonates may be critical to generate voluminous mafic magmas and to form the giant Xiarihamu Ni–Cu deposit and other magmatic sulfide deposits in convergent settings worldwide. The relatively high δ26Mg, high (87Sr/86Sr)i, and low εNd(t) of most orthopyroxenites, websterites, and gabbronorites were produced by extensive contamination of isotopically heavy crustal rocks in a deep-seated magma chamber. The slightly low δ26Mg, extremely high (87Sr/86Sr)i and negative εNd(t) of the marginal facies, compared with other websterites and gabbronorites, were governed by assimilation of local low-δ26Mg country rocks (e.g. gneiss and marble) at the Xiarihamu magma chamber during emplacement. These observations indicate that mafic–ultramafic cumulates away from marginal facies can preserve their primitive Mg–Sr–Nd isotope signatures inherited from deep magma chambers, even from mantle sources, with negligible crustal contamination during magma ascent and emplacement. These findings for the first time, to our knowledge, provide observational evidence to characterize the integrated magmatic processes of a single magma plumbing system from deep mantle source to magma chambers, which sheds light on the petrogenesis and mineralization of mafic–ultramafic intrusions.
Economically important Ni-Cu sulfide deposits occur in orogenic belts worldwide. However, the duration of timing and geological processes critical for generation of high-Mg basaltic magma and Ni-Cu ...sulfide mineralization during orogeny have not been well addressed. Here, we report a detailed geochronological study on the Huangshan-Jingerquan Ni-Cu metallogenic belt, NW China. The complexes were regarded as the results of a prolonged basaltic magmatism from 380 Ma to 270 Ma according to previous zircon U-Pb ages. Most of the zircons for the previous age dating were separated from mafic facies and only a few from ultramafic rocks. However, the Ni-Cu sulfide ore bodies are mostly hosted within the ultramafic facies. Thus, there are debates on tectonic setting of the magmatism associated with the Ni-Cu sulfide mineralization. In this study, the zircons separated from the sulfide-mineralized mafic/ultramafic facies of eleven complexes display U-Pb ages ranging from 285 to 280 Ma, indicating a short-lived high-Mg basaltic magmatism associated with the Ni-Cu mineralization. It is likely that the olivine-free gabbros formed in 380–300 Ma and 280–270 Ma occurred in subduction and post-collisional periods, respectively. Collision combined with regional strike-slip shearing at the latest Carboniferous induced slab break-off and asthenosphere upwelling in early Permian. Decompression melting of the upwelling asthenosphere was extensively intensified by addition of water released from the broken slab and generated voluminous high-Mg basaltic magma beneficial to the short-lived Ni-Cu sulfide mineralization in 285–280 Ma. The regional strike-slip shearing created fracture networks as pathways for magma ascending. The sulfides carried by the ascending basaltic magma deposited in the fractures and magma chambers in different depths and produced the sulfide-mineralized dykes and complexes, respectively.
•Precise age data are essential to relations of magmatism with tectonic evolution.•Ni-Cu metallogenesis is merely related the basaltic magma in early post-collision.•Sulfides carried by basaltic magma deposited in magma conduit in variable depths.
To better understand Fe isotope fractionation between mafic minerals and oxides during crystallization of mafic magma and sub-solidus re-equilibration, the Fe isotopes of whole-rocks and separated ...minerals (olivine, clinopyroxene, magnetite and ilmenite) of the Baima mafic layered intrusion, SW China, have been investigated. The separated minerals show a systematical decrease in δ57Fe values, from magnetite (0.15 to 0.51‰) to olivine (−0.11 to 0.15‰) and clinopyroxene (−0.35 to 0.05‰) and then to ilmenite (−0.82 to −0.10‰), demonstrating regular fractionation between these minerals. Except for a few of samples, most of the olivine and clinopyroxene are similar to those of mantle xenoliths in Fe isotopes, indicating that Fe isotope equilibrium reached during magma crystallization was well preserved. By contrast, the Fe isotopes of the magnetite and ilmenite may be evidently modified by sub-solidus re-equilibration via the Fe3+ versus Ti4+ and Fe2+ exchange between the oxides. Furthermore, the sub-solidus re-equilibration in Fe isotope is strongly controlled by the proportions of magnetite and ilmenite in rocks. Therefore, although the δ57FeIlm of the Lower Zone rocks with magnetite/ilmenite ratios as high as 6–10 was reduced evidently by the sub-solidus re-equilibration, the magnetite preserved their original Fe isotope compositions. By contrast, the Fe isotopes of both most magnetite and ilmenite in the Middle Zone had been markedly modified by sub-solidus re-equilibration owing to the moderate magnetite/ilmenite ratios (4–7). The decreases of both δ57FeMt and δ57FeOl upwards in the cyclic units of the Lower Zone reveal that extensive early fractional crystallization of the magnetite resulted in depletion of heavier Fe isotopes in the magma. On the other hand, early crystallization of olivine and clinopyroxene gave rise to the slight elevation of δ57FeOl values upwards in the cyclic units of the Middle and Upper zones. The stratigraphic reversals in the δ57FeMt and δ57FeOl values suggest multiple magma recharges. Additionally, the δ57FeOl values in the base of the Lower Zone (0.10 to 0.15‰) indicate that the parental magma were heavy in Fe isotope due to extensive silicate mineral fractionation at depth. This study indicates fractionation in Fe isotope between silicates and oxides during magma crystallization and sub-solidus re-equilibration.
•Fe isotopic equilibrium fractionation between Ol and Cpx was well preserved.•δ57Fe values of Fe–Ti oxides may be overprinted by sub-solidus re-equilibration.•Early crystallization of magnetite results in depletion of heavier Fe isotope in magma.•Crystallization of mafic-silicates leads to magma enriched in heavier Fe isotope.
To evaluate whether crop rooting system was directionally dependent, a field digitizer was used to measure post-paddy wheat root architectures. The acquired data was transferred to Pro-E, in which ...virtual root architecture was reconstructed and projected to a series of planes each separated in 10° apart. Fractal dimension and fractal abundance of root projections in all the 18 planes were calculated, revealing a distinctive architectural distribution of wheat root in each direction. This strongly proved that post-paddy wheat root architecture was directionally dependent. From seedling to turning green stage, fractal dimension of the 18 projections fluctuated significantly, illustrating a dynamical root developing process in the period. At the jointing stage, however, fractal indices of wheat root architecture resumed its regularity in each dimension. This wheat root architecture recovered its dimensional distinctness. The proposed method was applicable for precision modeling field state root distribution in s
Magnaporthe oryzae (Anamorph: Pyricularia oryzae), the causal agent of rice blast disease, is the major pathogen that reduces the yield of rice worldwide. Melanin biosynthesis inhibitors (MBIs) and ...strobilurins (QoIs) are common fungicides used to control the disease. One hundred and three M. oryzae isolates from different rice-production areas in Taiwan were evaluated for their molecular phylogeny and sensitivity to MBI and QoI fungicides. Molecular phylogenetic analysis showed that all M. oryzae isolates could be classified into nine genetic groups (A–I) based on the DNA polymorphism amplified by CNS1/MP primers. Predominant ones are groups A (72 isolates) and B (15 isolates). Fungicide tests showed that M. oryzae isolates were sensitive to MBIs (carpropamid and tricyclazole) and less sensitive to QoIs (kresoxim-methyl and azoxystrobin). Amplifying the cytochrome b (cyt b) gene revealed that isolates with low sensitivity to QoIs did not correspond with mutation at codon 129 or 143 in the cyt b gene.
Human breast cancer is the predominant malignancy and the leading cause of cancer death in women from Western societies. The
cause of breast cancer is still unknown. Recently, the association between ...human prolactin (hPRL) activity and breast cancer
has been reemphasized. Biologically active hPRL has been found to be produced locally by breast cancer cells that contain
high levels of PRL receptor. A high incidence of mammary tumor growth has also been found in transgenic mice overexpressing
lactogenic hormones. More importantly, it has been demonstrated that the receptors for sex steroids and PRL are coexpressed
and cross-regulated. In this study, we report that we have designed and produced a hPRL antagonist, hPRL-G129R. By using cell
proliferation assays, we have demonstrated that: ( a ) hPRL and E2 exhibited an additive stimulatory effect on human breast cancer cell (T-47D) proliferation; ( b ) hPRL-G129R possessed an inhibitory effect on T-47D cell proliferation; and ( c ) when antiestrogen (4-OH-tamoxifen) and anti-PRL (hPRL-G129R) agents were added together, an additive inhibitory effect was
observed. We further investigated the mechanism of the inhibitory effects of hPRL-G129R in four hPRLR positive breast cancer
cell lines. We report that hPRL-G129R is able to induce apoptosis in all four cell lines in a dose-dependent manner as determined
by the Terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling assay. The apoptosis is induced within 2 h of
treatment at a dose as low as 50 ng/ml. We hope that the hPRL antagonist could be used to improve the outcome of human breast
cancer therapy in the near future.
Rice (
L.) is the principle staple crops in the World and its production can be severely damaged by
species. Several
species including
,
,
,
,
, have been recorded to cause rice seedling root rot in ...Taiwan (List of Plant Diseases in Taiwan edited by Tzean et al., 2019). During the survey of rice seedling diseases, we identified a new species of
that causes seedling root rot on rice in commercial nursery trays in two nursery fields in 2019 in Taichung, Taiwan. Stunting and root rot symptom were found on the affected plants and up to 20% seedlings in a nursery tray showed similar symptoms. To isolate the pathogen, symptomatic roots were surface sterilized with 75% ethanol for 1 min and rinsed in sterile water. The margin of lesion was cut off, placed on 1.5% water agar and incubated at 28 ℃. After 24 h, the hyphal tips of a white colony growing from the diseased region were transferred to potato dextrose agar (PDA) medium. Koch's postulates were fulfilled by inoculating the germinated rice seeds with mycelia. Rice seeds of
var. Tainan11 (TN11) were treated with 75% ethanol and then 1.2% NaOCl for 15 min. The sterilized seeds were soaked in sterile water under dark condition for 3 days and the water was replaced every day. Five of the pre-germinated seeds with 2~5 mm embryonic shoot were placed in a sterile petri-dish and inoculated with 3-ml mycelial suspension (OD
= 0.045) prepared by blending the mycelia of a 3-days PDA culture using an Oster 10 speed blender 6640 (Oster, USA). The seeds-mycelia were then covered with sterilized soil mixture of Akadama soil and rice husk (1:1, volume to volume) and incubated in a growth chamber at 28 ℃. Seven days post-inoculation, the inoculated seedlings showed stunting with short and necrotic roots (Fig. S1). The pathogen was reisolated from the diseased seedlings and identified with morphology and molecular methods. For morphological characterization, the pathogen was cultured on V8 agar to produce oogonia and zoospore (Chamswarng and Cook 1985). Globose oogonia with multiple antheridia (1-5 per oogonium), inflated filamentous sporangia, vesicle with abundant zoospores, main hypha with up to 6.57 μm wide and mature aplerotic oospores with diameter 24.35-30.81 μm (average= 27.22 μm; n=20) were observed (Fig. S1) that are similar to the descriptions for
(van der Plaats-Niterink 1981). Genomic DNA was extracted with CTAB method (Wang and White 1997) and the sequences of the internal transcribed spacer (ITS) region and gene region of β-tubulin (
) and cytochrome c oxidase subunit II (
II) were amplified with published primers (Villa et al., 2006). The obtained sequences were submitted to GenBank (accession nos: OL701302 (ITS), OL763269 (tub), and OL763270 (cox II); Fig. S2). Phylogenetic relationships between this
pathogen and other 55
isolates, including the type species of
(ATCC11101), were conducted with the concatenated sequences of tub and cox II and analyzed by Bayesian interference (Fig. S3). Based on the tree built with
and
II sequences, this pathogen was identified as
that has not been reported in rice and other plants in Taiwan. It was observed in laboratory assays that this pathogen caused significant root-rot symptoms on several major rice varieties grown in Taiwan, including TN11, Tainung67 and Kaoshiung139. It may potentially cause severe crop loss in rice production, especially in nurseries. This identification provides important information on rice disease management.
It is widely accepted that the incorporation of external sulfur via crustal contamination is an important trigger for sulfide immiscibility that generates Ni-Cu-(PGE) sulfide mineralization, yet ...other controlling factors for sulfide immiscibility may also be present. The late Permian Panzhihua, Baima, Hongge, Xinjie and Taihe layered intrusions in the Emeishan Large Igneous Province (ELIP, SW China), are well-endowed with Fe-Ti oxide deposits, whereas their sulfide mineralization is mainly sub-economic. For example, the lower part of the Xinjie intrusion hosts a few thin PGE-rich ore layers, yet other ELIP layered intrusions do not contain any Ni-Cu sulfide mineralization and are PGE-depleted (0.01-1 ppb). Compared with the PGE-undepleted Emeishan high-Ti basalts that are genetically related to the intrusions, the extent of PGE depletion and elevated Cu/Pd ratios (up to 3.2x10^sup 6^) of the Panzhihua, Baima, Taihe and Hongge intrusions suggest PGE-depletion in their parental magmas due to early-stage sulfide removal. Sr-Nd isotopic compositions of the Panzhihua, Baima and Taihe intrusions suggest crustal contamination was insignificant and sulfide saturation produced mainly by crustal sulfur input was unlikely. MELTS modeling shows that extensive fractionation of chromite, olivine and clinopyroxene in deep-seated magma chambers may have induced early-stage sulfide saturation of the primary magmas. The relatively high sulfide contents in the Fe-Ti oxide layers at Panzhihua, Baima, Hongge and Taihe indicate a close relationship between the second-stage sulfide immiscibility and extensive Fe-Ti oxide crystallization. Positive correlations between sulfur and total Fe^sub 2^O^sub 3^, V and TiO^sub 2^ suggest that Fe-Ti oxide (magnetite and ilmenite) crystallization may have triggered the second-stage sulfide saturation via sharply lowering the Fe concentration and oxygen fugacity of the magmas. Moderate degree of crustal contamination for the Xinjie Fe-Ti oxide-barren rocks may have induced sulfide saturation and accumulation at the lower part of the intrusion. Our calculations indicate that the Xinjie PGE-rich rocks have high R-factors (1000-10000), which are ascribed to PGE-upgrading of the sulfides via reaction with new replenishments of PGE-undepleted magmas. A few Panzhihua, Baima and Taihe samples that contain higher PGE concentrations suggest that the early-stage sulfide droplets at depths were entrained in later magma pulses delivered to shallower magma chambers. The very high R-factors determined by mass balance calculation, implies a good potential for discovering more PGE mineralization in the deep-seated intrusions of the magma plumbing system.
PDF
