THE EFFECTS OF ALTERED AQUATIC AND AERIAL RESPIRATORY GAS CONCENTRATIONS ON AIR-BREATHING PATTERNS IN A PRIMITIVE FISH (AMIA CALVA)

1993 ◽  
Vol 181 (1) ◽  
pp. 81-94 ◽  
Author(s):  
M. S. Hedrick ◽  
D. R. Jones

The mechanisms and physiological control of air-breathing were investigated in an extant halecomorph fish, the bowfin (Amia calva). Air flow during aerial ventilation was recorded by pneumotachography in undisturbed Amia calva at 20–24°C while aquatic and aerial gas concentrations were independently varied. Separation of aquatic and aerial gases was used in an attempt to determine whether Amia calva monitor and respond to changes in the external medium per se or to changes in dissolved gases within the body. Air flow measurements revealed two different types of ventilatory patterns: type I air-breaths were characterized by exhalation followed by inhalation; type II air-breaths, which have not been described previously in Amia calva, consisted of single inhalations with no expiratory phase. Expired volume (Vexp) for type I breaths ranged from 11.6+/−1.1 to 26.7+/− 2.9 ml kg-1 (95 % confidence interval; N=6) under normoxic conditions and was unaffected by changes in aquatic or aerial gases. Gas bladder volume (VB), determined in vitro, was 80 ml kg-1; the percentage of gas exchanged for type I breaths ranged from 14 to 33 % of VB in normoxia. Fish exposed to aquatic and aerial normoxia (PO2=19-21 kPa), or aerial hypercapnia (PCO2=4.9 kPa) in normoxic water, used both breath types with equal frequency. Aquatic or aerial hypoxia (PO2=6-7 kPa) significantly increased air-breathing frequency in four of eight fish and the ventilatory pattern changed to predominantly type I air-breaths (75–92 % of total breaths). When fish were exposed to 100 % O2 in the aerial phase while aquatic normoxia or hypoxia was maintained, air-breathing frequency either increased or did not change. Compared with normoxic controls, however, type II breaths were used almost exclusively (more than 98 % of total breaths). Type I breaths appear to be under feedback control from O2-sensitive chemoreceptors since they were stimulated by aquatic or aerial hypoxia and were nearly abolished by aerial hyperoxia. These results also indicate that Amia calva respond to changes in intravascular PO2; however, externally facing chemoreceptors that stimulate air-breathing in aquatic hypoxia cannot be discounted. Type II air- breaths, which occurred in aerial hyperoxia, despite aquatic hypoxia, appear to be stimulated by reductions of VB, suggesting that type II breaths are controlled by volume-sensitive gas bladder stretch receptors. Type II breaths are likely to have a buoyancy-regulating function.

1999 ◽  
Vol 202 (1) ◽  
pp. 87-94
Author(s):  
M.S. Hedrick ◽  
D.R. Jones

The purpose of this study was to investigate the roles of branchial and gas bladder reflex pathways in the control of gill ventilation and air-breathing in the bowfin Amia calva. We have previously determined that bowfin use two distinct air-breathing mechanisms to ventilate the gas bladder: type I air breaths are characterized by exhalation followed by inhalation, are stimulated by aquatic or aerial hypoxia and appear to regulate O2 gas exchange; type II air breaths are characterized by inhalation alone and possibly regulate gas bladder volume and buoyancy. In the present study, we test the hypotheses (1) that gill ventilation and type I air breaths are controlled by O2-sensitive chemoreceptors located in the branchial region, and (2) that type II air breaths are controlled by gas bladder mechanosensitive stretch receptors. Hypothesis 1 was tested by examining the effects of partial or complete branchial denervation of cranial nerves IX and X to the gill arches on gill ventilation frequency (fg) and the proportion of type I air breaths during normoxia and hypoxia; hypothesis II was tested by gas bladder inflation and deflation. Following complete bilateral branchial denervation, fg did not differ from that of sham-operated control fish; in addition, fg was not significantly affected by aquatic hypoxia in sham-operated or denervated fish. In sham-operated fish, aquatic hypoxia significantly increased overall air-breathing frequency (fab) and the percentage of type I breaths. In fish with complete IX-X branchial denervation, fab was also significantly increased during aquatic hypoxia, but there were equal percentages of type I and type II air breaths. Branchial denervation did not affect the frequency of type I air breaths during aquatic hypoxia. Gas bladder deflation via an indwelling catheter resulted in type II breaths almost exclusively; furthermore, fab was significantly correlated with the volume removed from the gas bladder, suggesting a volume-regulating function for type II air breaths. These results indicate that chronic (3–4 weeks) branchial denervation does not significantly affect fg or type I air-breathing responses to aquatic hypoxia. Because type I air-breathing responses to aquatic hypoxia persist after IX-X cranial nerve denervation, O2-sensitive chemoreceptors that regulate air-breathing may be carried in other afferent pathways, such as the pseudobranch. Gas bladder deflation reflexly stimulates type II breaths, suggesting that gas bladder volume-sensitive stretch receptors control this particular air-breathing mechanism. It is likely that type II air breaths function to regulate buoyancy when gas bladder volume declines during the inter-breath interval.


1994 ◽  
Vol 197 (1) ◽  
pp. 429-436
Author(s):  
M Hedrick ◽  
S Katz ◽  
D Jones

The ventilatory patterns of air-breathing fish are commonly described as 'arrhythmic' or 'irregular' because the variable periods of breath-holding are punctuated by seemingly unpredictable air-breathing events (see Shelton et al. 1986). This apparent arrhythmicity contrasts with the perceived periodism or regularity in the gill ventilation patterns of some fish and with lung ventilation in birds and mammals. In this sense, periodism refers to behaviour that occurs with a definite, recurring interval (Bendat and Piersol, 1986). The characterisation of aerial ventilation patterns in fish as 'aperiodic' has been generally accepted on the basis of qualitative examination and it remains to be validated with rigorous testing. The bowfin, Amia calva (L.), is a primitive air-breathing fish that makes intermittent excursions to the air­water interface to gulp air, which is transferred to its well-vascularized gas bladder. Its phylogenetic position as the only extant member of the sister lineage of modern teleosts affords a unique opportunity to examine the evolution of aerial ventilation and provides a model for the examination of ventilatory patterns in primitive fishes. To establish whether Amia calva exhibit a particular pattern of air-breathing, we examined time series records of aerial ventilations from undisturbed fish over long periods (8 h). These records were the same as those used to calculate average ventilation intervals under a variety of experimental conditions (Hedrick and Jones, 1993). Their study also reported the occurrence of two distinct breath types. Type I breaths were characterised by an exhalation followed by an inhalation, whereas type II breaths were characterised by inhalation only. It was also hypothesized that the type I breaths were employed to meet oxygen demands, whereas the type II breaths were used to regulate gas bladder volume. However, they did not investigate the potential presence of a periodic ventilatory pattern. We now report the results of just such an analysis of ventilatory pattern that demonstrates a clear periodism to air-breathing in a primitive fish.


2000 ◽  
Vol 203 (21) ◽  
pp. 3279-3287 ◽  
Author(s):  
M.E. Castello ◽  
P.A. Aguilera ◽  
O. Trujillo-Cenoz ◽  
A.A. Caputi

This paper describes the peripheral mechanisms involved in signal processing of self- and conspecific-generated electric fields by the electric fish Gymnotus carapo. The distribution of the different types of tuberous electroreceptor and the occurrence of particular electric field patterns close to the body of the fish were studied. The density of tuberous electroreceptors was found to be maximal on the jaw (foveal region) and very high on the dorsal region of the snout (parafoveal region), decaying caudally. Tuberous type II electroreceptors were much more abundant than type I electroreceptors. Type I electroreceptors occurred exclusively on the head and rostral trunk regions, while type II electroreceptors were found along as much as 90 % of the fish. Electrophysiological data indicated that conspecific- and self-generated electric currents are ‘funnelled’ by the high conductivity and geometry of the body of the fish. These currents are concentrated at the peri-oral zone, where most electroreceptors are located. Moreover, within this region, field vector directions were collimated, constituting the most efficient stimulus for electroreceptors. It can be concluded that the passive properties of the fish tissue represent a pre-receptor device that enhances exafferent and reafferent electrical signals at the fovea-parafoveal region.


1935 ◽  
Vol 61 (4) ◽  
pp. 545-558 ◽  
Author(s):  
Geoffrey Rake

The investigation of this isolated epidemic of meningococcus meningitis at a C.C.C. camp gave an opportunity to examine the carrier state in contacts carrying what were presumably virulent epidemic strains of organisms. With the aid of Miller's technique for the enhancement of the demonstrable virulence of meningococci for mice, it proved possible to test the virulence of the carrier strains from Camp Rusk. These results were consistent despite the interval of from 3 to 4 weeks which intervened between the isolation of the strains and the virulence titrations. Type I strains were found to have a high virulence, while the virulence of Type II strains was moderately high but definitely less than that of the Type I, and atypical strains and strains of N. catarrhalis isolated from carriers showed a very low virulence. The question of the precise nature of the carrier state was investigated. No evidence has been obtained yet as to the existence of a relationship between pharyngitis, coryza or upper respiratory disease and the presence and degree of the carrier state. This is unlike the situation with regard to pneumococcus carriers. On the other hand, it has proved possible to demonstrate reactions within the body to the meningococci in the nasopharynx, consisting of the formation of agglutinins and protective antibodies in the blood serum. 32.3 per cent of Type I and 60 per cent of Type II carrier sera showed moderate or good agglutinins for homologous organisms and 80 per cent of Type I and 40 per cent of Type II sera showed moderate or good protective antibodies against virulent homologous strains. No idea could be obtained as to the relationship of the presence or absence and the degree of serological reaction and the duration of the carrier state.


2020 ◽  
Vol 56 (2) ◽  
pp. 135
Author(s):  
Krisnawan Andy Pradana ◽  
Viskasari P Kalanjati ◽  
Ni Wajan Tirthaningsih

Higher prevalence of albuminuria, glycosuria, and haematuria was reported in the obese people than control. We aimed to analyze the BMI and urinalysis markers among the university students aged 18-21 years old in the IIKBW, Kediri to study any correlations and differences between these variables, which to the best of our knowledge has yet widely reported in Indonesia. This study has ethics approval from Universitas Airlangga, Surabaya. The BMI was analyzed from the body weight and height of male (n=74) and female (n=76) students with no health problems recorded. The pH, nitrites, protein, erythrocytes, glucose in the urine were measured qualitatively with a dip-stick method, blinded, using the midstream urine sample collected in the morning. Data were analyzed using SPSS 17, with a level of significance of p<0.05. Abnormal pH (n=75), positive nitrites (n=24), haematuria (n=6), and proteinuria (n=149) were recorded. About 22% of students suffered from type I obesity, and 8.7% of type II. Males were significantly suffered from the obesity whilst females from the overweight (p<0.05). No significant correlations between the BMI and each urinalysis marker (BMI and nitrites p=0.936; BMI and protein p=1; BMI and pH p=0.835; BMI and blood, p=0.486; respectively); no one were found with glycosuria. No significant differences either on the BMI or the 5 urinalysis markers between male and female groups (p>0.05). Whilst no positive glycosuria samples were identified; 18.9% of males and 13.2% of females have positive nitrites, 100% of males and 98.7% of females have positive proteinuria, 2.7% of males and 7.9% of females have positive haematuria. There were 7.33% of males and 6% of females having an increased pH; whilst 20.66% of males and 16% of females having a decreased pH. Amongst the seemingly healthy university students, we found cases of urinalysis marker impairment, although no significant correlations on the BMI to the urinalysis markers that may be representing early detection for renal diseases were observed.


2020 ◽  
Vol 33 (12) ◽  
pp. 1930-1939
Author(s):  
Liuhong Shen ◽  
Yingkun Zhu ◽  
Jinbang Xiao ◽  
Bolin Qian ◽  
Liuchao You ◽  
...  

Objective: This study was conducted to investigate the differences in several serum adipokines in perinatal dairy cows with type I and II ketosis, and the correlations between these adipokines and the two types of ketosis.Methods: Serum adiponectin (ADP), leptin (LEP), resistin, tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6) levels, and energy balance indicators related to ketosis were measured. Type I and II ketosis were distinguished by serum glucose (Glu) and Y values and the correlations between adipokines in the two types of ketosis were analyzed.Results: β-Hydroxybutyric acid of type I ketosis cows was significantly negatively correlated with insulin (INS) and LEP and had a significant positive correlation with serum ADP. In type II ketosis cows, ADP and LEP were significantly negatively correlated, and INS and resistin were significantly positively correlated. Revised quantitative INS sensitivity check index (RQUICKI) values had a significantly positive correlation with ADP and had a very significant and significant negative correlation with resistin, TNF-α, and IL-6. ADP was significantly negatively correlated with resistin and TNF-α, LEP had a significantly positive correlation with TNF-α, and a significantly positive correlation was shown among resistin, IL-6, and TNF-α. There was also a significant positive correlation between IL-6 and TNF-α.Conclusion: INS, ADP, and LEP might exert biological influences to help the body recover from negative energy balance, whereas resistin, TNF-α, and IL-6 in type II ketosis cows exacerbated INS resistance and inhibited the production and secretion of ADP, weakened INS sensitivity, and liver protection function, and aggravated ketosis.


1919 ◽  
Vol 30 (2) ◽  
pp. 123-146 ◽  
Author(s):  
Mildred C. Clough

In this paper are reported the results of a study of nine strains of pneumococci agglutinating with antipneumococcus sera of all three types (Nos. I, II, and III). Seven of the strains were the cause of serious or fatal infections in human beings. Morphologically they were typical pneumococci with characteristic growth on ordinary media. Most of the strains were soluble in bile, fermented inulin, and caused no precipitation on glucose ascitic fluid agar. Two of the strains, however, resembled streptococci in these three cultural characteristics, but have been regarded as pneumococci on account of their serological reactions. Variations in the cultural reactions occurred with several strains while they were under observation. The virulence of the strains varied greatly, some strains being almost non-pathogenic, and others killing mice in doses of 0.000001 cc. of a 24 hour broth culture. Antipneumococcus Sera I, II, and III agglutinated all the strains in fairly high dilution (1:8 to 1:64 or higher), while normal horse serum caused no agglutination. Antipneumococcus Sera I, II, and III stimulated active phagocytosis of all the strains, while no phagocytosis occurred in control preparations with normal horse serum. These strains elaborated a soluble substance in the body of inoculated mice which caused the formation of a precipitate when the peritoneal washings, cleared by centrifugalization, were added to the antipneumococcus sera of all three types. Antipneumococcus Sera I, II, and III protected mice equally well against 1,000 to 10,000 times the minimal lethal dose of the two strains with which protection tests could be carried out. Absorption of serum of Types I and II with the homologous pneumococcus removed the agglutinins and the bacteriotropins for all these strains. Absorption of these sera with Strains T and N removed the agglutinins and the bacteriotropins for the homologous strain only, and not for typical members of Type I or II, or for the other atypically agglutinable strains reported in this paper. The agglutinins concerned in the agglutination of these peculiar strains are therefore minor agglutinins. As shown not only by agglutination tests, but also by protection tests and agglutinin absorption tests, these organisms bear the same relation to Types I, II, and III, as do atypical Type II strains to Type II. Immune sera were prepared with these strains, and each strain was tested with all the immune sera by means of phagocytic and agglutinative reactions. In general, the strains were found to be serologically distinct, though some interrelationships existed between Strains V and R, and between Strains H, F, and N. These sera had no activity towards strains belonging to Type I or II, or atypical Type II. A mutation occurred in one of the strains, B, while it was under observation. On isolation this strain had the cultural reactions of a typical pneumococcus, and had the phagocytic and agglutinative reactions of an atypical Type II. After 6 months cultivation on blood agar its serological reactions changed, and it became actively phagocyted and agglutinated in antipneumococcus sera of Types I, II, and III. Its cultural characteristics also changed, and it became bile-insoluble, did not ferment inulin, and caused precipitation in glucose ascitic fluid agar. At this time it caused an intense green discoloration at the base of the blood agar slants around the water of condensation. By repeated animal passages this strain was three times made to revert abruptly to its original form (atypical Type IIa), both in cultural and serological reactions. An immune serum was prepared to each form of the strain, and each serum acted strongly on the homologous form, but was without action on the heterologous form of the strain. This mutation suggests that these pneumococci reacting with all three types of antipneumococcus sera may represent primitive, relatively undifferentiated forms from which the fixed types may have arisen.


1983 ◽  
Vol 61 (9) ◽  
pp. 1964-1967 ◽  
Author(s):  
Donald L. Kramer ◽  
E. Anne Braun

To examine the hypothesis that breathing patterns in fish capable of bimodal respiration can be modified by ecological factors that alter the relative costs of air and water breathing, we determined the air-breathing frequency and activity of a group of Corydoras aeneus before and after presentation of small amounts of food. In nature a reduction in air breathing while feeding on small, patchy resources should reduce loss of food to competitors and lower the risk of failing to relocalize the food source. Activity always increased after food presentation, but the change in air breathing depended on dissolved oxygen tension. Air breathing decreased after food presentation at 116 and 72 torr (1 torr = 133.322 Pa), stayed the same at 44 torr, and increased at 24 torr. This suggests that although oxygen demand increases during feeding, air breathing is decreased when the ambient conditions permit a compensatory increase in the uptake of dissolved oxygen.


2021 ◽  
Author(s):  
Behzad Rajabi ◽  
Mahdi Vadizadeh

Abstract GaXIn1-XAs/GaYIn1-YSb vertical heterojunctionless tunneling field effect transistor (VHJL-TFET) has been suggested to optimize the digital benchmarking parameters. In the proposed VHJL-TFET with type II heterostructure (i.e. X=0.8, Y=0.85), slight changes in gate voltage cause switching from OFF-state to ON-state. As a result, the electrical properties of Ga0.8In0.2As/Ga0.85In0.15Sb VHJL-TFET are excellent in the sub-threshold region. The heterostructure with III-V semiconductors in the source-channel region increases the ON-state current (ION (of the VHJL-TFET. Comparing the results of Ga0.8In0.2As/Ga0.85In0.15Sb VHJL-TFET with the simulated devices with type I heterostructure (i.e. X=0.9, Y=0.1) and type III heterostructure (i.e. X=0.1, Y=0.4) shows the improvement by 26% and 15% in the average subthreshold slope (SS). Sensitivity analysis for VHJL-TFET with the type II heterostructure shows that the sensitivity of OFF-state current (IOFF) to the body thickness (Tb) and doping concentration (ND) is more than the sensitivity of the other main electrical parameters. The Ga0.8In0.2As/Ga0.85In0.15Sb VHJL-TFET with a channel length of 20 nm, Tb=5 nm, and ND=1×1018cm-3 showed the SS=4.4mV/dec, ION/IOFF=4E14, and ION=8mA/um. As a result, Ga0.8In0.2As/Ga0.85In0.15Sb VHJL-TFET can be a reasonable choice for digital applications.


Author(s):  
Behzad Rajabi ◽  
Mahdi Vadizadeh

Ga[Formula: see text]In[Formula: see text]As/Ga[Formula: see text]In[Formula: see text]Sb vertical heterojunctionless tunneling field effect transistor (VHJL-TFET) has been suggested to optimize the digital benchmarking parameters. In the proposed VHJL-TFET with type II heterostructure (i.e., [Formula: see text] and [Formula: see text]), slight changes in gate voltage cause switching from OFF-state to ON-state. As a result, the electrical properties of Ga[Formula: see text]In[Formula: see text]As/Ga[Formula: see text]In[Formula: see text]Sb VHJL-TFET are excellent in the sub-threshold region. The heterostructure with III–V semiconductors in the source-channel region increases the ON-state current ([Formula: see text]) of the VHJL-TFET. Comparing the results of Ga[Formula: see text]In[Formula: see text]As/Ga[Formula: see text]In[Formula: see text]Sb VHJL-TFET with the simulated devices with type I heterostructure (i.e., [Formula: see text] and [Formula: see text]) and type III heterostructure (i.e., [Formula: see text] and [Formula: see text]) shows the improvement by 26% and 15% in the average subthreshold slope (SS). Sensitivity analysis for VHJL-TFET with the type II heterostructure shows that the sensitivity of OFF-state current ([Formula: see text] to the body thickness ([Formula: see text] and doping concentration ([Formula: see text] is more than the sensitivity of the other main electrical parameters. The Ga[Formula: see text]In[Formula: see text]As/Ga[Formula: see text]In[Formula: see text]Sb VHJL-TFET with a channel length of 20 nm, [Formula: see text] nm, and [Formula: see text] cm[Formula: see text] showed the [Formula: see text] mV/dec, [Formula: see text]/[Formula: see text], and [Formula: see text] mA/um. As a result, Ga[Formula: see text]In[Formula: see text]As/Ga[Formula: see text]In[Formula: see text]Sb VHJL-TFET can be a reasonable choice for digital applications.


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