Ultrastructure of the podia of Amphiura chiajei and Amphiura filiformis and their role in feeding

2006 ◽  
Vol 86 (4) ◽  
pp. 817-822 ◽  
Author(s):  
John K. Keogh ◽  
Brendan F. Keegan
Keyword(s):  
Chemical Composition ◽  
Morphological Study ◽  
Secretory Cells ◽  
Suspension Feeding ◽  
Head Region ◽  
Feeding Styles ◽  
Amphiura Filiformis ◽  
The Difference ◽  
Mucus Cells ◽  
Deposit Feeding

Morphological study of the podia of the suspension feeding Amphiura filiformis and the deposit feeding Amphiura chiajei revealed sensory–secretory complexes in the podial epidermis, consisting of four cells, two secretory and two sensory. Large mucus cells were found in association, but not exclusively, with the sensory–secretory complexes. In A. filiformis, mucus cells stained positively for both acid and neutral mucopolysaccharides, while, in A. chiajei, these cells stained only for acid mucopolysaccharides. The surfaces of the arm podia in A. chiajei were relatively smooth, while the arm podia of A. filiformis bear papillae. The sensory–secretory complexes open through numerous paired pores, with each pair having an intervening cilium. Pores were restricted to the podial tip in A. chiajei, while in A. filiformis they are concentrated on the podial tip and on the papillae. Amphiura chiajei shows very little differentiation of the podia along the length of the arm. In A. filiformis, the distal podia have papillae throughout their entire length, with pores being found on the head region and the papillar tips. Here, the papillae are oriented in such a way (i.e. facing inward towards the ventral arm plate) as to increase the area of the filtering surface of the podium, serviced by the sticky secretions from the sensory–secretory complexes. The proximal podia are relatively simple in structure and are thought to function more in the transportation of mucus wrapped particles to the mouth rather than in their capture. The difference in structure of the podia and chemical composition of podial secretory cells are taken to reflect the difference in feeding styles of the two species.

The Origin of the Moon

1962 ◽  
Vol 14 ◽  
pp. 149-155 ◽  
Author(s):  
E. L. Ruskol
Keyword(s):  
Chemical Composition ◽  
Solar System ◽  
The Moon ◽  
The Earth ◽  
The Difference ◽  
Origin Of The Moon

The difference between average densities of the Moon and Earth was interpreted in the preceding report by Professor H. Urey as indicating a difference in their chemical composition. Therefore, Urey assumes the Moon's formation to have taken place far away from the Earth, under conditions differing substantially from the conditions of Earth's formation. In such a case, the Earth should have captured the Moon. As is admitted by Professor Urey himself, such a capture is a very improbable event. In addition, an assumption that the “lunar” dimensions were representative of protoplanetary bodies in the entire solar system encounters great difficulties.

Ultrastructure of scent glands in larvae of Apateticus bracteatus (Hemiptera: Pentatomidae) and chemical composition of the secretion

1980 ◽  
Vol 58 (11) ◽  
pp. 2105-2115 ◽  
Author(s):  
Jean Percy ◽  
J. A. MacDonald ◽  
J. Weatherston
Keyword(s):  
Chemical Composition ◽  
Interstitial Cells ◽  
Secretory Cells ◽  
Scent Glands ◽  
Volatile Constituents ◽  
Dorsal Wall ◽  
Anterior Dorsal ◽  
Glandular Cells ◽  
Gland Function ◽  
Dorsal Abdominal Glands

The three dorsal abdominal glands in larvae of Apateticus bracteatus (Pentatomidae) secrete a mixture of compounds. Major volatile constituents of the secretion are identified, herein, as tridecane and 2-octenal. There are also trace amounts of 2-hexenal and two other unidentified compounds.Each of the glands has paired orifices that are located between tergites 3/4, 4/5, and 5/6, but only the most anterior gland is paired. In anterior glands of midinstar larvae, glandular cells associated with ducts, and interstitial glandular cells are distributed along the ventral walls of the reservoirs. In posterior glands, columnar glandular cells are located in the anterior dorsal wall of the reservoirs; secretory cells associated with ducts, and nonglandular interstitial cells are distributed throughout the ventral and posterior walls of the reservoirs. The interstitial glandular cells of the anterior gland and the columnar glandular cells of the middle and posterior glands contain cytoplasmic organelles characteristic of lipid-producing cells. In all glands the secretory cells associated with ducts secrete lipids. Evidence indicating the importance of Golgi and ER in secretion synthesis is presented. The reservoirs and ducts have a thin cuticular lining.The bearing of the results on present ideas of gland function in Heteroptera is discussed.

On the difference of aerosol hygroscopicity between high and low RH environment in the North China Plain

2021 ◽  
Author(s):  
Jingnan Shi ◽  
Juan Hong ◽  
Nan Ma ◽  
Qingwei Luo ◽  
Hanbing Xu ◽  
...  
Keyword(s):  
Chemical Composition ◽  
North China Plain ◽  
North China ◽  
Experimental Period ◽  
Formation Mechanisms ◽  
Large Contribution ◽  
The North ◽  
The North China Plain ◽  
The Difference ◽  
Aerosol Hygroscopicity

<p>Simultaneous measurements of aerosol hygroscopicity and chemical composition were performed at a suburban site in the North China Plain in winter 2018 using a self-assembled hygroscopic tandem differential mobility analyzer (H-TDMA) and a capture-vaporizer time-of-flight aerosol chemical speciation monitor (CV-ToF-ACSM), respectively. During the experimental period, aerosol particles usually show an external mixture in terms of hygroscopicity, with a less hygroscopic particles mode (LH) and a more hygroscopic mode (MH). The average ensemble mean hygroscopicity parameter (κ<sub>mean</sub>) are 0.16, 0.18, 0.16, and 0.15 for 60, 100, 150, and 200 nm particles, respectively. Two episodes with different RH/T conditions and secondary aerosol formations are distinguished. Higher aerosol hygroscopicity is observed for all measured sizes in the high RH episode (HRH) than in the low RH episode (LRH). In LRH, κ decreases as the particle size increases, which may be explained by the large contribution of non- or less-hygroscopic primary compounds in large particles due to the enhanced domestic heating emissions at low temperature. The number fraction of LH mode at 200 nm even exceeds 50%. Closure analysis is carried out between the HTDMA-measured κ and the ACSM-derived hygroscopicity using different approximations for the hygroscopic parameters of organic compounds (κ<sub>org</sub>). The results indicate that κ<sub>org</sub> is less sensitive towards the variation of its oxidation level under HRH conditions but has a stronger O: C-dependency under LRH conditions. The difference in the chemical composition and their corresponding physical properties under different RH/T conditions reflects potentially different formation mechanisms of secondary organic aerosols at those two distinct episodes.</p>

The Isothermal Oxidation of MCrAlY Protective Coatings

2021 ◽  
Vol 1016 ◽  
pp. 407-412
Author(s):  
Marcin Drajewicz ◽  
Tadeusz Kubaszek ◽  
Barbara Kościelniak ◽  
Marek Góral ◽  
Dawid Dziadosz
Keyword(s):  
Chemical Composition ◽  
Protective Coatings ◽  
Degradation Mechanism ◽  
Isothermal Oxidation ◽  
Jet Engine ◽  
Bond Coats ◽  
Spraying Parameters ◽  
The Difference ◽  
Plasma Sprayed ◽  
Oxidation Effect

The thermal barrier coatings (TBC) are commonly used for protection of jet engine parts. In presented article the influence of chemical composition of TBCs bond coats on isothermal oxidation resistance was analysed. The bond coat was plasma sprayed (APS) using different MCrAlY alloys produced by Oerlikon-Metco: Metco 4451, AMDRY 997, AMDRY 962, AMDRY 365-1, AMDRY 995C. The conducted research showed big difference in coating thickness despite the same spraying parameters. The difference in porosity was not observed. The isothermal oxidation test was conducted during 500h at 1100°C in static laboratory air. The obtained results showed, that degradation mechanism of MCrAlY bond coats regardless of chemical composition is similar. The formation of scale contained aluminium and chromium oxides was observed. The internal oxidation effect was also observed in produced coatings.

scholarly journals PERBEDAAN KARAKTERISTIK KIMIA DAN DAYA CERNA PATI TEPUNG JAGUNG DAN TEPUNG KECAMBAH JAGUNG (Zea mays L.)

2018 ◽  
Vol 7 (1) ◽  
pp. 43
Author(s):  
Willem Kurniawan Lombu ◽  
Ni Wayan Wisaniyasa ◽  
AAI. Sri Wiadnyani
Keyword(s):  
Zea Mays ◽  
Chemical Composition ◽  
Moisture Content ◽  
Zea Mays L ◽  
Starch Content ◽  
Fat Content ◽  
Ash Content ◽  
Starch Digestibility ◽  
Corn Flour ◽  
The Difference

This study aims to determine the difference of characteristic and starch digestibility of germinated and ungerminated flour. This study used randomized complete design (RCD) three repeated. The corn germinated for 36 hours. Corn germinated flour and ungerminated flour were evaluated directly of the chemical composition of the flour content, moisture content, ash content, protein, fat, carbohydrates, fiber, starch content and starch digestibility. The results showed the corn germinated flour has increased of moisture content from 9.66% into 10.38%, increased of protein into 7.22% into 8.45%, increased of fiber content from 2.28% into 2.79% and increased of starch digestibility from 57.04% into 62.43%. While were the decreased fat content from 5.17% into 4.76%, decreased of carbohydrate from 75.41% into 73.89% and decreased of starch content from 76.10% into 69.40%. The treatmented has no effect for the flour content decreased from 41.40% into 40.36% and ash content decreased from 2.52% into 2.51%. Germinated increased starch digestibility and changed the character of corn flour.

Describing the lactation curve of dairy animals

1999 ◽  
Vol 1999 ◽  
pp. 197-197 ◽  
Author(s):  
G. E. Pollott
Keyword(s):  
Secretory Cell ◽  
Empirical Models ◽  
Secretory Cells ◽  
Cell Numbers ◽  
Biological Meaning ◽  
Lactation Curve ◽  
Dairy Animals ◽  
The Difference ◽  
Daily Milk Yield ◽  
Daily Milk

Most functions used to describe the lactation curve of dairy animals are empirical in approach and result in parameters with little or no biological meaning. A new model for describing lactation based on the biology of the pregnant and lactating animal is proposed and compared to several empirical models (Wood, 1967; Grossman and Koops, 1988; Morant and Gnanasakthy, 1989).Lactation is thought of as the balance between an increase in secretory cell numbers (NSCP) and their later decline (NSCD). The difference between them is the number of active secretory cells, each of which secretes milk at a particular rate (S kg/cell/day). Thus daily milk yield (MY) = (NSCP – NSCD) x S.

scholarly journals Quality Properties and Pyrolysis Characteristics of Cassava Rhizome Pellets Produced by Alternating between Pelletizing and Torrefaction

Processes ◽  
2019 ◽  
Vol 7 (12) ◽  
pp. 930
Author(s):  
Nitipong Soponpongpipat ◽  
Paisan Comsawang ◽  
Suwat Nanetoe
Keyword(s):  
Chemical Composition ◽  
Thermogravimetric Analysis ◽  
Energy Density ◽  
Bulk Density ◽  
Moisture Absorption ◽  
Pyrolysis Temperature ◽  
Quality Properties ◽  
Pyrolysis Characteristics ◽  
Durability Index ◽  
The Difference

This work investigated quality properties of pellets of raw cassava rhizome (P-RC), pellets of pelletized cassava rhizome followed by torrefaction (T-CP), and pellets of torrefied cassava rhizome followed by pelletizing (P-TC). Torrefaction was conducted at temperatures of 230, 250, and 280 °C for 30 min. Pyrolysis characteristics of T-CP and P-TC at torrefied temperatures of 230 and 250 °C were studied using thermogravimetric analysis. It was found that at the similar torrefied temperature, P-TC had a higher bulk density, energy density, and pellet durability than that of T-CP and P-RC while T-CP had a higher HHV and moisture absorption than P-TC and P-RC. The bulk density of P-TC was 1.13–1.19 and 1.33–1.52 times higher than that of P-RC and T-CP, respectively. The HHV of T-CP was 1.07 and 1.29 times higher than P-TC and P-RC, respectively. The energy density of P-TC was 1.24–1.56 and 1.20–1.41 times higher than that of P-RC and T-CP. In terms of Pellet Fuel Institute (PFI) standard, the durability index of P-RC, P-TC, and T-CP at torrefied temperatures of 230 and 250 °C was acceptable. However, dramatically low and unacceptable durability index was found in case of T-CP at torrefied temperature of 280 °C. The moisture absorption of P-TC was lower than that of P-RC and T-CP. Finally, T-CP had a lower pyrolysis temperature and had a much lower solid yield than that of P-TC. Variation of pyrolysis characteristics indicated the difference in chemical composition between T-CP and P-TC.

scholarly journals Placebo controlled trial of enteric coated pancreatin microsphere treatment in patients with unresectable cancer of the pancreatic head region

Gut ◽  
1998 ◽  
Vol 42 (1) ◽  
pp. 92-96 ◽  
Author(s):  
M J Bruno ◽  
E B Haverkort ◽  
G P Tijssen ◽  
G N J Tytgat ◽  
D J van Leeuwen
Keyword(s):  
Weight Loss ◽  
Confidence Interval ◽  
Pancreatic Duct ◽  
Pancreatic Head ◽  
Pancreatic Enzymes ◽  
High Dose ◽  
Head Region ◽  
Biliary Endoprosthesis ◽  
The Difference ◽  
Enteric Coated

Background—Impeded flow of pancreatic juice due to mechanical obstruction of the pancreatic duct in patients with cancer of the pancreatic head region causes exocrine pancreatic insufficiency with steatorrhoea and creatorrhoea. This may contribute to the profound weight loss that often occurs in these patients.Aims—To investigate whether pancreatic enzyme replacement therapy prevents this weight loss.Patients—Twenty one patients with unresectable cancer of the pancreatic head region with suspected pancreatic duct obstruction, a biliary endoprosthesis in situ, and a Karnofsky performance status greater than 60.Methods—Randomised double blind trial of eight weeks with either placebo or high dose enteric coated pancreatin enzyme supplementation. All patients received dietary counselling.Results—The mean difference in the percentage change of body weight was 4.9% (p=0.02, 95% confidence interval for the difference: 0.9 to 8.9). Patients on pancreatic enzymes gained 1.2% (0.7 kg) body weight whereas patients on placebo lost 3.7% (2.2 kg). The fat absorption coefficient in patients on pancreatic enzymes improved by 12% whereas in placebo patients it dropped by 8% (p=0.13, 95% confidence interval for the difference: –6 to 45). The daily total energy intake was 8.42 MJ in patients on pancreatic enzymes and 6.66 MJ in placebo patients (p=0.04, 95% confidence interval for the difference: 0.08 to 3.44).Conclusions—Weight loss in patients with unresectable cancer of the pancreatic head region and occlusion of the pancreatic duct can be prevented, at least for the period immediately after insertion of a biliary endoprosthesis, by high dose enteric coated pancreatin enzyme supplementation in combination with dietary counselling.

Studies of Copper Surfaces modified by Thermal and Plasma Treatments

2000 ◽  
Vol 612 ◽  
Author(s):  
G.P. Beyer ◽  
M. Baklanov ◽  
T. Conard ◽  
K. Maex
Keyword(s):  
Chemical Composition ◽  
Thermal Treatment ◽  
Photoelectron Spectroscopy ◽  
Hydrogen Plasma ◽  
Copper Film ◽  
Copper Surface ◽  
Ex Situ ◽  
Clean Room ◽  
Copper Surfaces ◽  
The Difference

AbstractIt was found that copper surfaces, which had been exposed to a clean room atmosphere, were covered by a layer, whose chemical composition can be described by Cu(OH)2·CuCO3. This layer can effectively be removed by either a short thermal treatment in vacuum at 350°C, a hydrogen plasma treatment, or a combination of both. Ex-situ photoelectron spectroscopy measurements show little difference of the chemical composition of the surface after the respective treatments. The thermal treatment, however, gives rise to re-crystallisation of the copper film due to the difference in temperature of deposition and the anneal. Ex-situ ellipsometry measurements indicate that the hydrogen plasma not only removes Cu(OH)2·CuCO3 but also passivates the copper surface.

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