Floral micromorphology, histochemistry, ultrastructure and chemical composition of floral secretions in three Neotropical Maxillariella species (Orchidaceae)

Author(s):  
Monika M Lipińska ◽  
Natalia Wiśniewska ◽  
Marek Gołębiowski ◽  
Magdalena Narajczyk ◽  
Agnieszka K Kowalkowska

Abstract Floral morphological adaptations and composition of secretions aim to ensure reproductive success. Maxillariella is part of the largest subtribe of Orchidaceae, and Maxillariella spp. are important components of the orchid flora of the Neotropics. The aim of this paper was to provide a detailed study of the reproductive biology of three morphologically and geographically distinct species: M. sanguinea, M. variabilis and M. vulcanica. For many years, species in this group were considered rewardless, but several studies have revealed that lips of some species may secrete resins. However, most published research has mainly focused on investigating either micromorphology (SEM, TEM, histochemistry) or fragrance composition (GC–MS). In this study, we make the first attempt to investigate Maxillariella flowers in a more comparative manner by combining both aspects. In all investigated species we reported the presence of resins with lipids, sugars and/or proteins, suggesting a potential role as a food reward. Scant quantities of residues indicate that they are produced periodically in small quantities. Chemical analysis revealed significant differences between species, however, the presence of some compounds was constant. Cycloartenal and cycloartenol (main ingredients of resin and wax-like material in some Maxillariinae) were not been found.

Author(s):  
A. B. Edwards

During a petrological examination of samples of bauxite from Boolarra, in south Gippsland, Victoria, it was noted that some specimens of the bauxite, which is largely derived from Tertiary olivine-basalt, contained numerous grains of yellow-brown to amber-yellow leucoxene. The leucoxene is clearly pseudo-morphous after ilmenite, residual particles of ilmenite being enclosed in many of the leucoxene grains. Most of the leucoxene grains are opaque, but occasional grains are translucent to transparent, though isotropic. Some of them show parallel markings suggestive of cleavage, but probably a residual structure from the replaced ilmenite. In view of the highly aluminous nature of the enclosing rock, there seemed some possibility that this mineral might be the little-known aluminium titanate, xanthitane. It was thought, therefore, that if a pure sample of the mineral could be prepared, a chemical analysis would establish its identity.


2016 ◽  
Vol 310 (10) ◽  
pp. R906-R916 ◽  
Author(s):  
Alison D. Kreisler ◽  
Linda Rinaman

Published research supports a role for central glucagon-like peptide 1 (GLP-1) signaling in suppressing food intake in rodent species. However, it is unclear whether GLP-1 neurons track food intake and contribute to satiety, and/or whether GLP-1 signaling contributes to stress-induced hypophagia. To examine whether GLP-1 neurons track intake volume, rats were trained to consume liquid diet (LD) for 1 h daily until baseline intake stabilized. On test day, schedule-fed rats consumed unrestricted or limited volumes of LD or unrestricted volumes of diluted (calorically matched to LD) or undiluted Ensure. Rats were perfused after the test meal, and brains processed for immunolocalization of cFos and GLP-1. The large majority of GLP-1 neurons expressed cFos in rats that consumed satiating volumes, regardless of diet type, with GLP-1 activation proportional to intake volume. Since GLP-1 signaling may limit intake only when such large proportions of GLP-1 neurons are activated, a second experiment examined the effect of central GLP-1 receptor (R) antagonism on 2 h intake in schedule-fed rats. Compared with baseline, intracerebroventricular vehicle (saline) suppressed Ensure intake by ∼11%. Conversely, intracerebroventricular injection of vehicle containing GLP-1R antagonist increased intake by ∼14% compared with baseline, partly due to larger second meals. We conclude that GLP-1 neural activation effectively tracks liquid diet intake, that intracerebroventricular injection suppresses intake, and that central GLP-1 signaling contributes to this hypophagic effect. GLP-1 signaling also may contribute to satiety after large volumes have been consumed, but this potential role is difficult to separate from a role in the hypophagic response to intracerebroventricular injection.


2007 ◽  
Vol 50 (5) ◽  
pp. 851-860 ◽  
Author(s):  
Maria Sélia Blonski ◽  
Carlos Roberto Appoloni ◽  
Paulo Sérgio Parreira ◽  
Pedro Henrique Arruda Aragão ◽  
Virgilio Franco Nascimento Filho

Energy Dispersion X-Ray Fluorescence Technique (EDXRF) was employed to study the effects of the fumagina disease on the elementary chemical composition of the leaves. The experimental set up consisted of a Mo X-ray tube (Ksub<FONT FACE=Symbol>µ</FONT> = 17.44 keV) with Zr filter and a Si (Li) detector. The measurements were performed with the infected and healthy leaves of citric plants. The elements Ti, Mn, Fe, Cu and Zn were quantified, with an average DL of 69, 12, 8, 4 and 4 µg.g-1 respectively. The obtained concentration for Fe varied from 44 to 192 µg.g-1 in healthy leaves and from 363 to 704 µg.g-1 in infected leaves with fumagina .


2012 ◽  
Vol 65 (2) ◽  
pp. 233-240 ◽  
Author(s):  
Felipe Nylo de Aguiar ◽  
Felipe Fardin Grillo ◽  
Jorge Alberto Soares Tenório ◽  
José Roberto de Oliveira

The objective of this paper is to present an analysis of the use of residual marble mixtures in the pig iron desulfurization process. The study involved the use of: marble waste, fluorspar, lime, and hot metal. Four mixtures were made and added to a liquid hot metal - with known chemical composition - at a temperature of 1450ºC. The mass of each element was calculated from its chemical analysis and compared with an industrial mixture. All of the four mixtures used in the experiments were stirred by a mechanical stirrer. Samples were collected by vacuum sampling for times of 5, 10, 15, 20, and 30 minutes, and analysis was performed to check sulfur variation in the bath with time. The results were analyzed and they verified that it was possible to use marble waste as a desulfurizer.


2013 ◽  
Vol 13 (2) ◽  
pp. 53-58 ◽  
Author(s):  
A. Janus ◽  
A. Kurzawa

Abstract Determined was quantitative effect of nickel equivalent value on austenite decomposition degree during cooling-down castings of Ni-Mn- Cu cast iron. Chemical composition of the alloy was 1.8 to 5.0 % C, 1.3 to 3.0 % Si, 3.1 to 7.7 % Ni, 0.4 to 6.3 % Mn, 0.1 to 4.9 % Cu, 0.14 to 0.16 % P and 0.03 to 0.04 % S. Analysed were castings with representative wall thickness 10, 15 and 20 mm. Scope of the examination comprised chemical analysis (including WDS), microscopic observations (optical and scanning microscopy, image analyser), as well as Brinell hardness and HV microhardness measurements of structural components.


Author(s):  
DongHoon Choi ◽  
Jae-Hoon Kim

Mobile elevating work platforms (MEWPs) consist of a work platform, extending structure, and chassis, and are used to move persons to working positions. MEWPs are useful but are composed of pieces of equipment, and accidents do occur owing to equipment defects. Among these defects, accidents caused by the fracture of bolts fixed to the extension structure and swing system are increasing. This paper presents a failure analysis of the fixing bolts of MEWP. Standard procedure for failure analysis was employed in this investigation. Visual inspection, chemical analysis, tensile strength measurement, and finite element analysis (FEA) were used to analyze the failure of the fixing bolts. Using this failure analysis approach, we found the root cause of failure and proposed a means for solving this type of failure in the future. First, the chemical composition of the fixing bolt is obtained by a spectroscopy chemical analysis method, which determined that the chemical composition matched the required standard. The tensile test showed that the tensile and yield strengths were within the required capacity. The stress analysis was carried out at five different boom angles, and it was determined that the fixing bolt of MEWP can withstand the loads at all the boom angles. The outcomes of the fatigue analysis revealed that the fixing bolt fails before reaching the design requirements. The results of the fatigue analysis showed primarily that the failure of the fixing bolt was due to fatigue. A visual inspection of the fractured section of the fixing bolt also confirmed the fatigue failure. We propose a method to prevent failure of the fixing bolt of the MEWP from four different standpoints: the manufacturer, safety certification authority, safety inspection agency, and owner.


2018 ◽  
Vol 14 (2) ◽  
pp. 60-5
Author(s):  
Sri Utami Lestari ◽  
Muryanto Muryanto

The most consumed part of the plants is the leaf part so that the fertilizer provided should contain high nitrogen (N). The nature of the N fertilizer is volatile and when the rainy season there can be washing.  When plants deficienci nutrients shows symtoms of yellowing leaves so that the application of N fertilizer to the plant must remain unfulfilled.  Azolla is a usable alternative.  Azolla has a high N nutrient content because it is symbiotic with anabaena in binding to free nitrogen in the air.             The purpose of this study was to determine the chemical composition (pH,N,P,K) Azolla mycrophylla.  The experiment was conducted experimentally with the first stage of composting azolla after it was done chemical analysis in the laboratory.  The result of this research can be concluded that chemical analysis of Azolla mycrophylla cpmpost is as follows :pH 7,17, N 2,57%, P 0,34%, K 0,03%.  


Author(s):  
Carla Maria Mariano Fernandez ◽  
◽  
Fabiana Brusco Lorenzetti ◽  
Sirlene Adriana Kleinubing ◽  
Joao Paulo Pinguello de Andrade ◽  
...  

The present study aimed to analyze the chemical composition of the essential oil from Garcinia gardneriana (Planchon & Triana) Zappi leaves and fruits, and to determine its acaricidal activity on Rhipicephalus microplus by larval packet test and larvicidal action on Aedes aegypti by larval immersion test. The chemical analysis of the essential oil by gas chromatography-mass spectrometry identified sesquiterpene hydrocarbons and oxygenated sesquiterpenes in bacupari leaves and fruits, and α-cedrene, α-chamigrene, α-trans-bergamotene, and β-curcumene as major compounds. Essential oil from leaves of G. gardneriana presented acaricidal activity on R. microplus (LC50 = 4.8 mg/mL; LC99 = 10.8 mg/mL) and larvicidal effect on A. aegypti (LC50 = 5.4 mg/mL; LC99 = 11.6 mg/mL), whereas essential oil from the fruits of G. gardneriana showed LC50 = 4.6 mg/mL and LC99 = 8.9 mg/mL against R. microplus and LC50 = 6.4 mg/mL and LC99 = 13.9 mg/mL against A. aegypti. These results thus demonstrate the potential acaricidal and larvicidal activity of essential oil of G. gardneriana, offering new perspectives for the realization of bioassays from this essential oil.


1963 ◽  
Vol S7-V (5) ◽  
pp. 844-851 ◽  
Author(s):  
Jean Nicolas ◽  
Jean Paul Sagon

Abstract Observations on the dolerites of the northern flank of the E-W-trending Laniscat-Merleac anticline in NW France suggest that the rocks were emplaced as coulees. A well-marked granular differentiation in the rock supports this hypothesis; the coarse-grained rocks are in contact with Devonian rocks at the bottom of the coulee and the fine-grained rocks are in contact with Dinantian rocks at the top. Chemical analysis shows that there is a diminishing of Na &lt;sub&gt;2&lt;/sub&gt; O and an augmentation of the percentage of CaO ranging from the boundary of the coarse-grained rock to that of the fine-grained. Overlying the green rocks are green schists of comparable chemical composition attributed to former tuffs which were subject to regional epimetamorphism. Finally, a coarse-grained, green rock sample has been traced to the spilite family.


Author(s):  
D. L. Hamilton ◽  
C. M. B. Henderson

SummaryA method for the preparation of chemically homogeneous powders by a weighing and gelling technique is described in detail. Stress is placed on the importance of the weight yield as an indication of the bulk chemical composition and on the chemical analysis of several portions to test the homogeneity. A list of recommended chemicals is included in an appendix.


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