Ciliary Activity and Oxygen uptake in Branchiostoma Lanceolatum(Pallas)

1965 ◽  
Vol 43 (1) ◽  
pp. 1-12
Author(s):  
W. A. M. COURTNEY ◽  
R. C. NEWELL
Keyword(s):  
Oxygen Uptake ◽  
High Rate ◽  
Ciliary Activity ◽  
Oxygen Utilization ◽  
Nervous Control ◽  
Pharyngeal Wall ◽  
Temperature Range ◽  
Zero Rate ◽  
Branchiostoma Lanceolatum ◽  
Set Up

1. The rate of oxygen uptake by single specimens of Branchiostoma lanceolatum has been shown to vary considerably. Some animals in sealed vessels at 50° C. were able to utilize the oxygen linearly down to less than 20% of air saturation. Others ceased to absorb oxygen at high saturations while yet others displayed two different rates in a sequence starting initially with a high rate. 2. There are three possible rates of oxygen utilization, as well as a zero rate, for an animal at any temperature between 10 and 19° C. Animals in gravel exhibit only two rates at lower temperatures. 3. The slowest rate varies exponentially with temperature but the two faster rates show a rapid increase between 10 and 15° C. with little change outside this temperature range. 4. The effect of size and temperature on the increased oxygen uptake during the faster rates of respiration are discussed. It is suggested that ciliary activity of the pharynx could be associated with the extra oxygen utilization. 5. It has been found that there are three inhalant stream velocities, a fast, a slow and a zero rate with no intermediate rates. 6. Study of the isolated portions of the pharyngeal wall confirm that the fast inhalant current is set by the activity of all the cilia to give a feeding stream. The slow stream is set up by the lateral cilia, which continue to beat when the frontal cilia and most of the lateral cilia have been inhibited by lowered oxygen concentrations. 7. The lateral cilia have been shown to be under nervous control and to be inhibited by pressure on the pharyngeal bars. This mechanism depends on the presence of a connexion between the pharyngeal bars and the endostyle.

Experimental Study of a Full Forward Extrusion Process from Metal Strip

2012 ◽  
Vol 504-506 ◽  
pp. 587-592 ◽  
Author(s):  
Marion Merklein ◽  
Tommaso Stellin ◽  
Ulf Engel
Keyword(s):  
Extrusion Process ◽  
Metal Strip ◽  
Raw Material ◽  
High Rate ◽  
Process Chain ◽  
Forward Extrusion ◽  
Bulk Forming ◽  
Material Conditions ◽  
Set Up ◽  
Tooling System

A high rate of production of complex microparts is increasingly required by fields like electronics and micromechanics. Handling is one of the main problems, limiting those forming processes of small metal components consisting of multiple forming stages. A forming chain in which a metal strip acts both as raw material and support of the workpiece through the different stages of the process, is seen as a solution that radically simplifies the positioning of microparts. Each workpiece stays connected to the strip through all the forming steps, being separated just at the end of the process chain. In this work, a tooling system for the bulk forming from copper strips has been set up and employed in a full forward extrusion process of a micro-billet. The same die, with a diameter of 1 mm, has been used with three different strip thicknesses (1, 2 and 3 mm) and three different material conditions. The use of thinner and hard-as-rolled strips has resulted in achieving a higher ratio of the billet length to strip thickness.

Paternity, relationship, sexual activity and fertility in testicular cancer (TC) survivors (TCS): Results from a single institution observational prospective study.

2021 ◽  
Vol 39 (6_suppl) ◽  
pp. 380-380
Author(s):  
Davide Bimbatti ◽  
Francesco Pierantoni ◽  
Marco Maruzzo ◽  
Filippo Maria Deppieri ◽  
Aichi Msaki ◽  
...  
Keyword(s):  
Sexual Dysfunction ◽  
Premature Ejaculation ◽  
Relative Survival ◽  
High Dose Chemotherapy ◽  
High Rate ◽  
Interdisciplinary Management ◽  
High Dose ◽  
Family Status ◽  
Set Up ◽  
Status Data

380 Background: TC represents 1% of male neoplasms but it is the most common in young adults. Interdisciplinary management with chemotherapy, radiotherapy and surgery has led to a 10-year relative survival rate of up to 95%. These treatments (Tx) have short- and long-term side effects. While sexual dysfunction can reduce fertility, psychosocial distress can create relationship problems and finally affect the ability to procreate. Methods: From February 2020, we submitted a series of questionnaires to all the patients (pts) currently followed-up at the Istituto Oncologico Veneto free from TC recurrence for at least 2 years from the last Tx. International Index of Erectile Function (IIEF-15) and Premature Ejaculation Diagnostic Tool (PEDT) were used. We also set up a questionnaire to investigate paternity and family status. Data about disease and treatments were collected from medical records. Results: 84 TCS completed the questionnaires, clinical data are reported in the table below. 29,8% of pts fathered children before diagnosis with a strong correlation with older age at diagnosis (45,4 vs 30,8 years, p<0,001). After Tx, 14 pts had children: 9 of which naturally, 2 out 6 were successful via assisted reproductive technology (ART) (including one patient that received high-dose chemotherapy and stem cell transplantation), 3 via adoption. 89,3% of pts had stable relationships. Of pts who did not have children: 13,1% claimed to be due to lack of a partner, 39,3% claimed to be unready, while 14,3% had tried unsuccessfully to conceive. While 28,6% pts claim to currently have fertility issues, only 8,3% of pts reported to have these issues before diagnosis. 70,2% of pts performed a spermiogram after Tx, 10 pts had spermatogenic impairment. Higher rate of sexual dysfunction after Tx was detected by questionnaires while only 4 pts claimed to have had a pre-existing issue prior to TC diagnosis. PEDT shows that 38,1% had premature ejaculation and that in 22,6% this issue is highly probable. IIEF confirms a high rate of erectile dysfunction (14,3% severe and 10,7% mild or moderate). No correlations were identified between sexual dysfuntion and previous Tx. Conclusions: Most TCS had not planned fatherhood while 16,7% had children after Tx and 14.3% tried unsuccessfully to conceive. ART and adoption is possible but challenging and little used. PEDT and IIEF found high rates of sexual dysfunction but no association with previous Tx were found. [Table: see text]

scholarly journals Improving the performance of 241Am-Be for PGNAA applications using a proper shielding for neutron source and the NaI detector

2010 ◽  
Vol 25 (3) ◽  
pp. 205-211 ◽  
Author(s):  
Hamed Panjeh ◽  
Hashem Hakimabad ◽  
Lalle Motavalli
Keyword(s):  
Gamma Rays ◽  
Energy Region ◽  
Gamma Ray ◽  
Region Of Interest ◽  
High Rate ◽  
Prompt Gamma ◽  
Peak Resolution ◽  
Set Up ◽  
Gamma Ray Detector

The gamma ray spectrum resolution from a 241Am-Be source-based prompt gamma ray activation analysis set-up has been observed to increase in the energy region of interest with enclosing the NaI detector in a proper neutron and gamma ray shield. We have investigated the tact that the peak resolution of prompt gamma rays in the region of interest from the set-up depends on the source activity to the great extent, size and kind of the detector and the geometry of the detector shield. In order to see the role of a detector shield, five kinds of the detector shield were used and finally the proper kind was introduced. Since the detector shield has an important contribution in the reduction of the undesirable and high rate gamma rays coming to the gamma ray detector, a good design of a proper shield enables the elimination of the unwanted events, such as a pulse pile-up. By improving the shielding design, discrete and distinguishable photoelectric peaks in the energy region of interest have been observed in the spectrum of prompt gamma rays.

Respiration and Osmoregulation in Rainbow Trout with Gills Damaged by Zinc Sulphate

1970 ◽  
Vol 52 (2) ◽  
pp. 481-494
Author(s):  
J. F. SKIDMORE
Keyword(s):  
Rainbow Trout ◽  
Oxygen Uptake ◽  
Zinc Sulphate ◽  
Fold Increase ◽  
Oxygen Utilization ◽  
Osmotic Concentration ◽  
Sodium Potassium ◽  
Gill Ventilation ◽  
Calcium Magnesium ◽  
Zinc Sulphate Solution

1. Damage to the gill epithelium occurs when hatched fish are killed rapidly by solutions of zinc sulphate. 2. The rate of routine oxygen uptake by lightly sedated, quiet, rainbow trout did not alter on exposure to a rapidly toxic solution of zinc sulphate. However, oxygen utilization decreased seven-fold, gill ventilation volume increased six-fold, heart rate was halved, coughing rate increased 18-fold and the Po2 of dorsal aortic blood declined. 3. Unsedated trout usually struggled on exposure to zinc. The survival time of struggling fish was reduced and oxygen uptake increased, but other physiological changes were similar to those in quiet fish. 4. The respiratory changes in poisoned trout were generally similar to changes observed earlier in the same fish under hypoxia. 5. The osmotic concentration and the concentrations of sodium, potassium, calcium, magnesium and zinc in blood were largely unaffected by immobilization in zinc sulphate solution. Trout survived a four-fold increase in zinc concentration in the blood by injection. 6. The results suggest that epithelial damage decreased the permeability of the gills to oxygen, and did not increase their permeability to cations. Zinc was not a rapid internal poison. Death was probably caused by tissue hypoxia, when maximum gill ventilation was no longer sufficient to supply the oxygen needs of the fish.

Effects of 3,5-dibromo-4-hydroxybenzaldehyde O-(2,4-dinitrophenyl)oxime on Reactions of Mitochondria and Chloroplasts

Weed Science ◽  
1970 ◽  
Vol 18 (3) ◽  
pp. 419-426 ◽  
Author(s):  
D. E. Moreland ◽  
W. J. Blackmon
Keyword(s):  
Electron Transport ◽  
Oxygen Uptake ◽  
Electron Donor ◽  
Spinacia Oleracea ◽  
Herbicidal Activity ◽  
Oxygen Utilization ◽  
White Potato ◽  
Ferricyanide Reduction ◽  
Cyclic Photophosphorylation ◽  
Limited Oxygen

The effects of 3,5-dibromo-4-hydroxybenzaldehyde O-(2,4-dinitrophenyl)oxime (hereinafter referred to as C-9122), 3,5-dibromo-4-hydroxybenzonitrile (bromoxynil), 3,5-dibromo-4-hydroxybenzaldoxime (hereinafter referred to as bromoxime), and 2,4-dinitrophenol (hereinafter referred to as DNP) on phosphorylation and electron transport were measured in mitochondria isolated from white potato tubers (Solarium tuberosum L.) and in chloroplasts from spinach leaves (Spinacia oleracea L.). Mitochondrial oxygen utilization was monitored polarographically. All four chemicals stimulated ADP-limited oxygen utilization, inhibited non-ADP-limited oxygen uptake, and relieved oligomycin-inhibited oxygen uptake. C-9122 produced responses at lower molar concentrations than did bromoxynil, bromoxime, and DNP. The I50 value for inhibition of state 3 respiration by C-9122 was 2.7 × 10−6 M.In chloroplasts, C-9122, bromoxime, and DNP inhibited photoreduction and coupled photophosphorylation with water as the electron donor, and with ferricyanide and NADP as electron acceptors. Cyclic photophosphorylation, with phenazine methosulfate as the electron mediator under an argon gas phase, also was inhibited. With ascorbate-2,6-dichlorophenolindophenol (hereinafter referred to as DPIP) as the electron donor, phosphorylation coupled to NADP reduction was inhibited, but not the reduction of NADP. C-9122 was the strongest inhibitor, and bromoxime was the weakest inhibitor of the several reactions. The I50 value for inhibition of the coupled ferricyanide reduction was 4.6 × 10−6 M for C-9122. C-9122 appeared to act in two different ways by (a) inhibiting electron transport at or near photosystem II and the oxygen evolution pathway, and (b) interfering with energy transfer and the generation of ATP. Bromoxynil inhibited photoreduction and photophosphorylation reactions in which water served as the electron donor; but it was a very poor inhibitor of both cyclic photophosphorylation, and photophosphorylation coupled to NADP reduction with ascorbate-DPIP serving as the electron donor. Because of the pivotal role of ATP in cellular metabolism, it is conceivable that interference with ATP generation could be a major (but not necessarily the only) mechanism through which the herbicidal activity of C-9122 is expressed.

Nervous Control of Ciliary Activity

Science ◽  
1964 ◽  
Vol 146 (3652) ◽  
pp. 1692-1693 ◽  
Author(s):  
E. Aiello ◽  
G. Guideri
Keyword(s):  
Ciliary Activity ◽  
Nervous Control

The relationship between cirral activity and oxygen uptake in Balanus balanoides

1965 ◽  
Vol 45 (2) ◽  
pp. 387-403 ◽  
Author(s):  
R. C. Newell ◽  
H. R. Northcroft
Keyword(s):  
Body Weight ◽  
Oxygen Consumption ◽  
Oxygen Uptake ◽  
Mantle Cavity ◽  
The Body ◽  
Effect Of Temperature ◽  
Zero Rate ◽  
Rate Of Oxygen Consumption ◽  
The Relationship ◽  
Balanus Balanoides

The rate of cirral beat of Balanus balanoides is related to the logarithm of the body weight as an exponential function. In any one animal, there is little effect of temperature on cirral activity between 7·5° and 10° C. Between 10° and 20° C, however, there is a rapid increase in cirral beat with temperature followed by a fall at temperatures above 20° C.Balanus balanoides exhibits a fast, medium and zero rate of oxygen consumption. These rates of oxygen consumption correspond with (a) normal cirral beating, (b) ‘testing’ activity with no cirral movement, and (c) with the closure of the mantle cavity. Both of the possible levels of oxygen uptake are related to the logarithm of the body weight in a logarithmic fashion over the temperature range 7·5°–22·5° C. Temperature affects the two rates of oxygen consumption differently. In the slower rate (rate B) there is an increase in the rate of oxygen consumption between 7·5° and 14° C but there is no significant increase in the rate of oxygen consumption between 14° and 22·5 C°.

A ‘Hyaline’ Layer in the Skin of Squids

1997 ◽  
Vol 77 (4) ◽  
pp. 1247-1250 ◽  
Author(s):  
J.J. Madan ◽  
M.J. Wells
Keyword(s):  
Oxygen Uptake ◽  
Blood Vessels ◽  
Amorphous Material ◽  
Thick Layer ◽  
Extensive Literature ◽  
Potential Importance ◽  
Nervous Control ◽  
The Subject ◽  
The Brain

The skin of Loligo vulgaris and Illex illecebrosus contains a thick layer of amorphous material. In Loligo it lies above and in Illex below the chromatophore layer. We can find no mention of this layer in the considerable literature on squid skins despite its potential importance as a protection to underlying tissues and as a possible barrier to cutaneous oxygen uptake.Cephalopods have soft complicated skins. Embedded in the skin, most species have chromatophores, small bags of pigment that can be expanded by muscles that are under direct nervous control from the brain. There is an extensive literature on the physiology of chromatophores (Packard, 1988) and on their function in the behaviour of the animals (Hanlon & Messenger, 1996; Packard & Hochberg, 1977). Further cutaneous structures concerned in the determination of the colour of living cephalopods, the reflecting iridophores and leucophores (Cloney & Brocco, 1983), and the light generating photophores (Herring, 1988), have been the subject of a number of reports but other skin features such as the distribution of blood vessels have attracted little attention.

Effect of hemorrhagic hypotension on oxygen consumption of dogs

1964 ◽  
Vol 207 (3) ◽  
pp. 647-649 ◽  
Author(s):  
Elvin E. Smith ◽  
Jack W. Crowell
Keyword(s):  
Blood Flow ◽  
Oxygen Consumption ◽  
Oxygen Uptake ◽  
Arterial Pressure ◽  
Flow Rate ◽  
Blood Oxygen ◽  
Oxygen Utilization ◽  
Epinephrine Administration ◽  
Utilization Coefficient ◽  
Subsequent Rise

The effects of hematocrit, Dibenzyline, and epinephrine on oxygen consumption were studied in 220 dogs whose arterial pressure was lowered to and maintained at 30 mm Hg. Oxygen consumption was recorded previous to and during the period of hypotension. The average oxygen consumption was 7.20 ml/kg min prior to hemorrhage. Ten minutes after hemorrhage the oxygen consumption was 3.58 ml/kg min (50% of control). After 30 min of hypotension the oxygen consumption was 4.70 ml/kg min (65% of control), and the oxygen consumption increased to 5.33 ml/kg min (74% of control) after 1 hr. Pretreatment with Dibenzyline increased the oxygen consumption during the early stages of hypotension but had little effect in the latter stages. Epinephrine administration decreased the oxygen consumption during the entire hypotensive period. Previous studies have shown that the oxygen utilization coefficient approaches its maximal value during the hypotensive period; therefore, oxygen uptake becomes limited by the blood flow and the changes in oxygen consumption indicate changes in flow rate to active tissue. Simultaneous studies showed that the hematocrit influenced oxygen transport by effects on both the blood oxygen content and the blood flow. The results illustrate that animals with hematocrits of 35–39 are able to transport more oxygen than animals with other hematocrits. Evidence is presented to show that the initial fall and the subsequent rise in oxygen consumption during hypotension may be a local autoregulation of blood flow.

Assessment of Heat Transfer Effectiveness: Application to Shell Bitumen Plant, Takoradi, Ghana

2008 ◽  
Author(s):  
Anthony Simons ◽  
Solomon Nunoo
Keyword(s):  
Heat Transfer ◽  
Heat Losses ◽  
Heat Energy ◽  
Fuel Oil ◽  
High Rate ◽  
Liquefied Petroleum Gas ◽  
Temperature Range ◽  
The Face ◽  
Selection Of ◽  
Current Heat

At Shell Bitumen Plant, Takoradi, Beverley Thermal Fluid Heater (BTFH) generates heat energy to heat thermal fluid (Thermia B) which flows through heat exchanger and then heats bitumen which is to be maintained at temperature range of 140 °C to 160 °C before it is discharged. High rate of heat losses have been observed and in order to maintain the temperature range of bitumen at (140 °C to 160 °C), a lot of heat energy is needed to be generated which means higher fuel consumption for BTFH. Industrial fuel oil is used to fuel the BTFH. This paper assesses the existing insulation system on the plant and seeks to improve on it so as to cut down heat losses. Consequently, the work looked at the estimation of heat losses, selection of materials for heat transfer and lagging purposes. In this wise, the existing laggings were modified by introducing fibreglass between the asbestos and masonry and thus reducing the current heat lost by 78%. Heat from the exhaust gas which would have otherwise, gone wasted, was utilised by redesigning the chimney and this yielded 0.868 kW of heat energy to aid the heating of the bitumen. In the face of rising cost of fuel and taking cognizance of the fact that cheaper natural gas and liquefied petroleum gas could be produced in Ghana, it is recommended that the heater should be fueled by either of these gases.

Sign in / Sign up

Export Citation Format

Share Document