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1.
Abstract. Machair vegetation is reported for the first time from New Zealand. The habitat is similar to that of British machairs in climate, topography and generally in soil. pH and CaCO3 content are much lower through most of the sequence, though this difference may partly reflect the greater disturbance of British machair. Sea machair is present, predominantly comprising native species. This grades into machair proper, which contains many species found also in British machair. The machair includes Ammophila-occupied hillocks, a feature typical of British machair. Machair marsh is also present.  相似文献   
2.
Processing of mRNAs including, alternative splicing (AS), mRNA transport and translation regulation are crucial to eukaryotic gene expression. For example, >90% of the genes in the human genome are known to undergo alternative splicing thereby expanding the proteome production capacity of a limited number of genes. Similarly, mRNA export and translation regulation plays a vital role in regulating protein production. Thus, it is important to understand how these RNA binding proteins including alternative splicing factors (ASFs) and mRNA transport and translation factors regulate these processes. Here we report the expression of an ASF, serine-arginine rich splicing factor 10 (Sfrs10) and a mRNA translation regulation factor, CUGBP, elav like family member 4 (Celf4) in the developing mouse retina. Sfrs10 was expressed throughout postnatal (P) retinal development and was observed progressively in newly differentiating neurons. Immunofluorescence (IF) showed Sfrs10 in retinal ganglion cells (RGCs) at P0, followed by amacrine and bipolar cells, and at P8 it was enriched in red/green cone photoreceptor cells. By P22, Sfrs10 was observed in rod photoreceptors in a peri-nuclear pattern. Like Sfrs10, Celf4 expression was also observed in the developing retina, but with two distinct retinal isoforms. In situ hybridization (ISH) showed progressive expression of Celf4 in differentiating neurons, which was confirmed by IF that showed a dynamic shift in Celf4 localization. Early in development Celf4 expression was restricted to the nuclei of newly differentiating RGCs and later (E16 onwards) it was observed in the initial segments of RGC axons. Later, during postnatal development, Celf4 was observed in amacrine and bipolar cells, but here it was predominantly cytoplasmic and enriched in the two synaptic layers. Specifically, at P14, Celf4 was observed in the synaptic boutons of rod bipolar cells marked by Pkc-α. Thus, Celf4 might be regulating AS early in development besides its known role of regulating mRNA localization/translation. In all, our data suggests an important role for AS and mRNA localization/translation in retinal neuron differentiation.  相似文献   
3.
Question: Phytogenic mounds (nebkhas) ‐ the natural accumulation of wind‐blown sediments within or around the canopies of plants ‐ have been proposed as important structures for locally maintaining high species richness in coastal and arid ecosystems. Nebkhas are assumed to increase habitat heterogeneity, but what is the importance of the nebkha host species relative to other nebkha characteristics in determining the associated plant assemblages? Are some host species more effective in creating diversity hotspots, or does a single species‐area relationship apply to all nebkhas, regardless of host species? Can the influence of the host be ascribed to its indirect effects on abiotic attributes of the nebkha complex? Methods and location: We investigated plant species richness and composition on nebkhas around six psammophytic species on Mediterranean coastal dunes of the Sinai Peninsula. Results: Plant species richness was significantly related to nebkha size by the single power function according to the general prediction of island biogeography theory, but this relationship was modified ‐ though to a limited degree ‐ by nebkha host species identity. Canonical Correspondence Analysis revealed that nebkha host species identity and nebkha environmental and non‐environmental factors significantly explained species composition on the nebkhas, but host species identity did so to a greater extent. The latter might reflect differences in seed trapping ability or free space for colonization between host species. Conclusion: Differences in community composition and richness among nebkhas formed by different host species represent a key factor in the maintenance of plant diversity on arid coastal dunes.  相似文献   
4.
Excessive free radicals in human and animal bodies can cause oxidative stress (OS) which damages cells and tissues. Plant materials with high antioxidant potential would resolve the OS problem. Thus, this study proposed to investigate the total phenolic (TPC) and flavonoid contents (TFC), antioxidant capacities and cytotoxicity in 17 edible plant materials from herbs, fruits, vegetables and plant by-products available in Southeast Asia for future use in the food or feed industry. Among 17 plant materials, Syzygium aromaticum (clove), Camellia sinensi (green tea pomace) from the beverage industry and Persicaria odorata (Vietnamese coriander) showed a prominent amount of TPC and TFC. These three plants and their combination (1:1:1 ratio, v:v:v) also possessed a remarkable antioxidant function in terms of DPPH, ABTS and FRAP, as well as showing a strong ROS inhibition through HepG2 cells. The cytotoxicity test of the crude extract of clove, green tea pomace and Vietnamese coriander, or their combination can be used between 0.032 and 0.255, 0.011 to 0.088, 0.022 to 0.178 and 0.021 to 0.346 mg/mL, respectively, without impeding cell viability. A combined mixture of clove, green tea pomace and Vietnamese coriander revealed the synergistic properties of antioxidants and cell safety. This indicates that there is a potential use of various antioxidant bioactive compounds in plant materials tested for use as phytogenic antioxidant additives.  相似文献   
5.
Summary The axon hillock (AH) and initial segment (IS) of 10 Golgi neurons and 6 basket cells in the cerebellar cortex of the rat were investigated by electron microscopy using serial sections. An average of 10.4 and 11.3 synaptic terminals were observed to establish synaptic contact with the axon hillock region of Golgi and basket cells, respectively. Most of these terminals were identified as the varicosities of the ascending parallel fibers. It is suggested that the focal innervation of AH regions represents an excitatory input pattern which is basically different from the randomly distributed, huge, parallel-fiber input onto the dendritic trees of Golgi and basket cells. In contrast to Golgi and basket neurons, no accumulation of parallel-fiber synapses was observed around the AH of stellate cells. The IS proper of the three neuronal types were devoid of true axo-axonal synapses.  相似文献   
6.
Electrical Interactions via the Extracellular Potential Near Cell Bodies   总被引:1,自引:0,他引:1  
Ephaptic interactions between a neuron and axons or dendrites passing by its cell body can be, in principle, more significant than ephaptic interactions among axons in a fiber tract. Extracellular action potentials outside axons are small in amplitude and spatially spread out, while they are larger in amplitude and much more spatially confined near cell bodies. We estimated the extracellular potentials associated with an action potential in a cortical pyramidal cell using standard one-dimensional cable theory and volume conductor theory. Their spatial and temporal pattern reveal much about the location and timing of currents in the cell, especially in combination with a known morphology, and simple experiments could resolve questions about spike initiation. From the extracellular potential we compute the ephaptically induced polarization in a nearby passive cable. The magnitude of this induced voltage can be several mV, does not spread electrotonically, and depends only weakly on the passive properties of the cable. We discuss their possible functional relevance.  相似文献   
7.
This study explored the effects of natural growth promoters (phytogenic feed additives and organic acids) on animal performance, carcass characteristics, blood parameters, gut microflora composition, and microbe–host interactions in broiler chickens over a 42-day feeding period. Two-hundred-fifty-day-old chicks were randomly assigned to one of five treatments: (i) control diets (CON); (ii) control diets + 40 g/tons antibiotic growth promoter (AB); (iii) control diets + 3 kg/tons organic acids (ORG); (iv) control diets + 3 kg/tons phytogenic feed additives (PHY); (v) control diets + 3 kg/tons organic acids + phytogenic feed additive combination (COM). A non-significant differences (p > 0.05) were observed in broiler performance among treatments at 21 days of age; however, a gradually increasing body weight gain and reduced feed conversion ratio were observed at 42 days in treatments versus control group. Biochemical indices were non-significant (p > 0.05) except for decreased cholesterol (p < 0.05) and increased A/G ratio (p < 0.05) recorded in the treatment groups. The addition of PHY and ORG improved total counts of Enterococcus spp. and Lactobacillus spp. (p < 0.05) as well as reduced caecal and ileal Campylobacter spp. and Escherichia coli (p < 0.05). Correlation analysis elucidated beneficial bacteria (Enterococcus spp. and Lactobacillus spp.) were positively and pathogenic bacteria (Campylobacter spp. and E. coli) were negatively correlated (p < 0.05) with host weight gain. The findings indicated that dietary supplementation of PHY and ORG sustained balanced gut microflora, which in turn improved body weight. This study broadens the significance of using PHY and ORG as safe alternatives to antibiotic growth promoters for achieving healthier and economical broiler production.  相似文献   
8.
Processing of mRNAs including, alternative splicing (AS), mRNA transport and translation regulation are crucial to eukaryotic gene expression. For example, >90% of the genes in the human genome are known to undergo alternative splicing thereby expanding the proteome production capacity of a limited number of genes. Similarly, mRNA export and translation regulation plays a vital role in regulating protein production. Thus, it is important to understand how these RNA binding proteins including alternative splicing factors (ASFs) and mRNA transport and translation factors regulate these processes. Here we report the expression of an ASF, serine-arginine rich splicing factor 10 (Sfrs10) and a mRNA translation regulation factor, CUGBP, elav like family member 4 (Celf4) in the developing mouse retina. Sfrs10 was expressed throughout postnatal (P) retinal development and was observed progressively in newly differentiating neurons. Immunofluorescence (IF) showed Sfrs10 in retinal ganglion cells (RGCs) at P0, followed by amacrine and bipolar cells, and at P8 it was enriched in red/green cone photoreceptor cells. By P22, Sfrs10 was observed in rod photoreceptors in a peri-nuclear pattern. Like Sfrs10, Celf4 expression was also observed in the developing retina, but with two distinct retinal isoforms. In situ hybridization (ISH) showed progressive expression of Celf4 in differentiating neurons, which was confirmed by IF that showed a dynamic shift in Celf4 localization. Early in development Celf4 expression was restricted to the nuclei of newly differentiating RGCs and later (E16 onwards) it was observed in the initial segments of RGC axons. Later, during postnatal development, Celf4 was observed in amacrine and bipolar cells, but here it was predominantly cytoplasmic and enriched in the two synaptic layers. Specifically, at P14, Celf4 was observed in the synaptic boutons of rod bipolar cells marked by Pkc-α. Thus, Celf4 might be regulating AS early in development besides its known role of regulating mRNA localization/translation. In all, our data suggests an important role for AS and mRNA localization/translation in retinal neuron differentiation.  相似文献   
9.
The reproductive performance of ruminants is economically significant, and its improvement is a primary goal of the livestock industry to ensure its sustainability. Several approaches have been developed to use phytogenics as feed additives for several proposes, such as reducing methane emissions, and as an alternative to antibiotics. Phytogenics have potent antioxidant, anti-inflammatory, immunomodulatory, and metabolism-regulatory properties, and they are present at high levels in animal feeds. This current review considers the potential use of medicinal herbs on the reproductive performance of animals. The influence of diet on the fertility complications commonly noted in ruminants is of global interest. Although the effects of phytogenics on ruminant digestion and absorption are well-explored, their impact on reproductive performance remains poorly investigated. This review focuses on the influence of phytogenics on semen quality, hormonal profiles, and hematobiochemical indices in male ruminants. Based on available data, phytogenics are perceived to improve oocyte quality, reproductive performance, and pregnancy. However, further more comprehensive research on the benefits and potential hazards of the use of phytogenics is required to improve reproductive performance in ruminants.  相似文献   
10.
Few studies were published on the effect of nebkhas (phytogenic mounds) on species diversity and soil resources, but no detailed study has been conducted yet on possible specific influence of nebkhas on growth and survival of the plants associated with them. We studied the nebkhas of Salvadora persica and their effect on growth and survival of three woody species (Prosopis cineraria, Tamarix aphylla, and Capparis decidua) in the Ommanian coast of Hormozgan Province in the south of Iran. The results showed that mean height and mean canopy diameter of P. cineraria and T. aphylla trees and shrubs inhabiting nebkhas of Salvadora persica were considerably higher than those of plants of these species growing outside nebkhas. The reverse occurred in the case of C. decidua. Generally, the percentages of stems with dead parts were significantly lower in plants inhabiting the nebkha sites in comparison to comparable ones growing outside the nebkhas. Salvadora persica nebkhas are enriched with more soil nutrients in comparison to inter-nebkha sites. Soil accumulated per each hectare in the nebkhas of the study area dominated by trees of Salvadora persica amounted to 237.6 m3. This indicates the great importance of nebkhas in the protection of soil and the associating species.  相似文献   
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