Regulation of external respiration by the book-lung spiracles of the spiders, Araneus diadematus Clerck and A. marmoreus Clerck

1969 ◽  
Vol 47 (3) ◽  
pp. 355-364 ◽  
Author(s):  
G. L. Robinson ◽  
U. Paim
Keyword(s):  
External Respiration ◽  
Continuous Release ◽  
Ambient Concentrations ◽  
Araneus Diadematus

Recordings were made of the movements of the valves of the book-lung spiracles of Araneus diadematus Clerck and A. marmoreus Clerck. The slit-like spiracles of quiescent spiders were usually almost closed, but opened widely whenever the spiders moved. Respirometry indicated that CO2, retained in the spiders while the spiracles were closed, was released in bursts when the spiracles opened. High ambient concentrations of CO2 as well as lack of O2 caused spiracular opening and continuous release of CO2 from the spiders. It is suggested that CO2 elicits, whereas O2 inhibits, spiracular opening.

Effect of coating method on release of Glimepiride from porosity osmotic pump tablets (POPTs)

2020 ◽  
pp. 37-45
Keyword(s):  
In Vitro Release ◽  
Osmotic Pump ◽  
Release Time ◽  
Once Daily ◽  
Coating Solution ◽  
Continuous Release ◽  
Red Color ◽  
Coating Method ◽  
Osmotic Agent

In this study, once-daily porosity osmotic pump tablets (POPTs) of Glimepiride were prepared using HPMC K100M (61%), osmotic agent (30% NaCl) coated using two different coating techniques spraying and dipping methods. The coating solution composed of ethyl cellulose (7.5%) w\w in ethanol (90%), castor oil (2%) as water-insoluble plasticizer and Gingo red color (0.5% w\w). In both techniques, the coating level was adjusted to give a 10% increase in the weight of the tablets. The effect of the coating by dipping technique with an increase in the weight of tablet (10 %, 20% & 50%) was also investigated to see the effect coating level on the percentage of drug release from POPTs. The results of the in vitro release of Glimepiride from tablets coated by the spraying method showed longer release time (24 hrs) than those coated with dipping method. On the other hand, increasing the coating level by dipping method retarded the release of the drug from tablets. However, the same retardation effect on release as shown with the spraying technique was only obtained by increasing the coating level with a 50% increase in the weight of the tablet. Thus, coating by spraying is more efficient to prepare POPTs to give a continuous release of Glimepiride from once daily table with the lowest increase in the total weight of the tablet.

Atmospheric transport and deposition of trace elements to lake erie from Urban areas

1996 ◽  
Vol 33 (4-5) ◽  
pp. 259-265
Author(s):  
Gerald J. Keeler ◽  
Nicola Pirrone
Keyword(s):  
Trace Elements ◽  
Urban Areas ◽  
Lake Erie ◽  
Atmospheric Transport ◽  
Spatial And Temporal Variation ◽  
Deposition Flux ◽  
Emission Sources ◽  
Dry Deposition Flux ◽  
Ambient Concentration ◽  
Ambient Concentrations

A hybrid receptor-deposition (HRD) modeling approach was used to determine the spatial and temporal variation in the ambient concentration and dry deposition flux of trace elements on fine (< 2.5 mm) and coarse (> 2.5 mm) particulate matter over Lake Erie. Upper-air observations from the National Weather Service (NWS) and ambient concentrations measured at two sampling sites downwind of major emission sources in the Lake Erie basin were input to the model. An evaluation of the deposition flux of size-segregated trace elements to the lake during the over-water transport was performed. The average total (fine + coarse) deposition flux was 9.6 ng/m2-h for V, 70 ng/m2-h for Mn, 3.2 ng/m2-h for As, 4.2 ng/m2-h for Se, 10 ng/m2-h for Cd, and 43.3 ng/m2-h for Pb.

Ultrasonic cavitation driven fabrication of organic solvent free lignin/prochloraz nano capsules to promote resistance to photolysis and rain wash, and provide extended release performance

Holzforschung ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Jingtian Chen ◽  
Miao Wang ◽  
Yong Qian ◽  
Shanyuan Tan ◽  
Huan Wang ◽  
...  
Keyword(s):  
Organic Solvent ◽  
Uv Irradiation ◽  
Encapsulation Efficiency ◽  
Extended Release ◽  
Ultrasonic Cavitation ◽  
Solvent Free ◽  
Loading Capacity ◽  
One Pot ◽  
Continuous Release ◽  
Mango Leaves

Abstract Lignin is a natural macromolecular sun blocker and provides an ideal protection material for pesticides that have poor photostability. In this study, alkali lignin/prochloraz capsules (AL-P) were prepared via one-pot ultrasonic cavitation. The results demonstrated that the produced AL-P were uniform spheres with sizes of 170–375 nm. The prochloraz encapsulation efficiency (EE) and loading capacity (LC) reached as high as 91.8 and 98.5%, respectively. Adding a small of surfactant reduced the size of the capsules, but both EE and LC were decreased. AL-P exhibited excellent extended release performance. The cumulative release of AL-P in the first 45 h was 76.1% and continuous release was maintained after 96 h. The resulting AL-P have improved photostability under UV irradiation radiation. Finally, AL-P capsules were sprayed on the mango leaves and bananas to act as preservatives, AL-P capsules had stronger rain wash resistance and were better preserved demonstrating their industrial applicability. Together, organic solvent free AL-P capsules demonstrate a method to improve the efficiency of photosensitive pesticides.

scholarly journals Effects of the Fragrance Galaxolide on the Biomarker Responses of the Clam Ruditapes philippinarum

2021 ◽  
Vol 9 (5) ◽  
pp. 509
Author(s):  
Graziano Rilievo ◽  
Jacopo Fabrello ◽  
Marco Roverso ◽  
Sara Bogialli ◽  
Valerio Matozzo
Keyword(s):  
Enzyme Activities ◽  
Cellular Level ◽  
Ruditapes Philippinarum ◽  
Aquatic Environments ◽  
Antioxidant Enzyme Activities ◽  
Limited Data ◽  
Continuous Release ◽  
Biochemical Effects ◽  
Household Products ◽  
Oxidative Damage To Proteins

The musk fragrance Galaxolide® (HHCB) is widely used in personal care and household products. Its large use leads to a continuous release of the compound into aquatic environments. Although some studies on the presence of HHCB in ecosystems and biota have been conducted, limited data about its effects on organism biomarkers are available. This study aimed at investigating both cellular and biochemical effects of HHCB in the clam Ruditapes philippinarum. Mussels were exposed for 7, 14 and 21 days to 100 ng/L and 500 ng/L of HHCB in seawater, and the effects on haemocyte parameters and antioxidant enzyme activities in the gills and digestive gland were evaluated. In addition, the neurotoxic potential of HHCB and its capacity to cause oxidative damage to proteins were assessed. Overall, our results demonstrated that exposure to HHCB was able to induce changes in biomarker responses of mussels, mainly at the cellular level.

scholarly journals Landslide-Induced Mass Transport of Radionuclides along Transboundary Mailuu-Suu River Networks in Central Asia

2021 ◽  
Vol 13 (4) ◽  
pp. 698 ◽  
Author(s):  
Fengqing Li ◽  
Isakbek Torgoev ◽  
Damir Zaredinov ◽  
Marina Li ◽  
Bekhzod Talipov ◽  
...  
Keyword(s):  
Mass Transport ◽  
Surface Waters ◽  
Natural Radionuclides ◽  
River Basin Management ◽  
River Networks ◽  
Pollution Dispersion ◽  
Continuous Release ◽  
Political Conflicts ◽  
Exposure Pathway ◽  
Analysis System

Seismically triggered landslides are a major hazard and have caused severe secondary losses. This problem is especially important in the seismic prone Mailuu-Suu catchment in Kyrgyzstan, as it hosts disproportionately sensitive active or legacy uranium sites with deposited radioactive extractive wastes. These sites show a quasi-continuous release of radioactive contamination into surface waters, and especially after natural hazards, a sudden and massive input of pollutants into the surface waters is expected. However, landslides of contaminated sediments into surface waters represent a substantial exposure pathway that has not been properly addressed in the existing river basin management to date. To fill this gap, satellite imagery was massively employed to extract topography and geometric information, and the seismic Scoops3D and the one-dimensional numerical model, Hydrologic Engineering Centre, River Analysis System (HEC-RAS), were chosen to simulate the landslide-induced mass transport of total suspended solids (TSS) and natural radionuclides (Pb-210 as a proxy for modeling purposes) within the Mailuu-Suu river networks under two earthquake and two hydrological scenarios. The results show that the seismically vulnerable areas dominated in the upstream areas, and the mass of landslides increased dramatically with the increase of earthquake levels. After the landslides, the concentrations of radionuclides increased suddenly and dramatically. The peak values decreased along the longitudinal gradient of river networks, with the concentration curves becoming flat and wide in the downstream sections, and the transport speed of radionuclides decreased along the river networks. The conclusions of this study are that landslides commonly release a significant amount of pollutants with a relatively fast transport along river networks. Improved quantitative understanding of waterborne pollution dispersion across national borders will contribute to better co-ordination between governments and regulatory authorities of riparian states and, consequently, to future prevention of transnational political conflicts that have flared up in the last two decades over alleged pollution of transboundary water bodies.

The response of planktonic phosphate uptake and turnover to ultraviolet radiation in Lake Erie

2002 ◽  
Vol 59 (5) ◽  
pp. 778-786 ◽  
Author(s):  
C D Allen ◽  
R E.H Smith
Keyword(s):  
Ultraviolet Radiation ◽  
Lake Erie ◽  
Radiation Treatment ◽  
Phosphate Uptake ◽  
Ultraviolet B ◽  
Phosphate Limitation ◽  
Bacterial Cells ◽  
Near Surface ◽  
Ambient Concentrations ◽  
Uptake Activity

The hypothesis that ambient ultraviolet radiation (UVR), at near-surface intensities, may diminish phosphorus availability to phytoplankton was tested in Lake Erie in July and August of 1998 and 1999. Relative to samples exposed to photosynthetically active radiation (PAR, 400–700 nm) only, those exposed to ultraviolet-B (UVB, 280–320) and (or) ultraviolet-A (UVA, 320–400 nm) in natural sunlight, or kept in darkness, had diminished phosphate uptake rates at elevated (1 µM P) dissolved phosphate concentrations. By contrast, the specific uptake rate of dissolved phosphate at ambient concentrations (turnover rate) was not significantly affected by UVR or darkness. Turnover was usually dominated by particles smaller than 0.8 µm, whereas uptake from elevated concentrations was dominated by larger particles. The size distribution of turnover and uptake activity was not affected by radiation treatment. Chlorophyll a concentrations were decreased by sufficient exposure to UVB and (or) UVA and increased by deprivation of PAR (dark controls), but the concentration of bacterial cells was unaffected. The results showed that UVR inhibited the phosphate uptake potential of larger, probably algal, plankton but did not change the apparent severity of phosphate limitation at ambient concentrations.

scholarly journals Design features of the orb web of the spider, Araneus diadematus

1994 ◽  
Vol 5 (3) ◽  
pp. 280-287 ◽  
Author(s):  
Alun ap Rhisiart ◽  
Fritz Vollrath
Keyword(s):  
Design Features ◽  
Orb Web ◽  
Araneus Diadematus
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