Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “pH”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 145 records · Page 8Linked to original sources
PubMed1977

Light-induced pH changes and changes in absorbance of pH indicators in Rhodospirillum rubrum chromatophores.

1. The light-induced pH change of chromatophore suspensions from Rhodospirillum rubrum was stimulated significantly and similarly by KCl, NaCl, LiCl, RbCl, CsCl, MgCl2, MnCl2, and CaCl2. In the dark, the pH of chromatophore suspensions decreased immediately and markedly on adding these salts. 2. The light-induced pH change stimulated by KCl plus valinomycin was inhibited by LiCl and NaCl, but not by RbCl. 3. The optimum pH values for light-induced pH change and photosynthetic ATP formation were around 5 and 8, respectively. The amount of chromatophore-bound ubiquinone-10 reduced in the light was independent of pH from 5 to 9. At pH 8, the number of protons incorporated into chromatophores in the light was one-half of the number of ubiquinone-10 molecules reduced in the light. 4. Among several pH indicators tested, bromothymol blue (BTB) and neutral red (NR) showed absorbance changes on illumination of chromatophores. Although the pH change indicated by the absorbance change was opposite to the light-induced pH change of the medium, the effect of KCl on the absorbance changes of BTB and NR, and the effect of valinomycin on that of NR, but not on that of BTB, were similar to those on the light-induced pH change. 5. The light-induced absorbance change of BTB was significantly inhibited by NR, whereas that of NR was hardly influenced by BTB. 6. Oligomycin stimulated the light-induced absorbance change of BTB under either non-phosphorylating or phosphorylating conditions. On the other hand, that of NR under phosphorylating conditions was 50% of that under non-phosphorylating conditions, and was increased by oligomycin.

Bacterial Chromatophores↗
PubMed1990

P NMR Observations on the Effect of the External pH on the Intracellular pH Values in Plant Cell Suspension Cultures.

(31)P nuclear magnetic resonance (NMR) spectroscopy was used to monitor the response of oil palm (Elaeis guineensis) and carrot (Daucus carota) cell suspensions to changes in the external pH. An airlift system was used to oxygenate the cells during the NMR measurements and a protocol was developed to enable a constant external pH to be maintained in the suspension when required. Phosphonoacetic acid was used as an external pH marker and the intracellular pH values were measured from the chemical shifts of the cytoplasmic and vacuolar orthophosphate resonances. In contrast to earlier studies the cytoplasmic pH was independent of the external pH over the range 5.5 to 8.0 and it was only below pH 5.5 that the cytoplasmic pH varied, falling at a rate of 0.12 pH unit per external unit. Loss of pH control was observed in response to sudden increases in external pH with the response of the cells depending on the conditions imposed. A notable feature of the recovery from these treatments was the transient acidification of the cytoplasm that occurred in a fraction of the cells and overshoot phenomena of this kind provided direct evidence for the time dependence of the regulatory mechanisms.

Journal Article↗
PubMedDate not supplied

pH imaging. A review of pH measurement methods and applications in cancers.

Acid-base balance is altered in a variety of common pathologies, including COPD, ischemia, renal failure, and cancer. Because of robust cellular pH homeostatic mechanisms, most of the pathological alterations in pH are expressed as changes in the extracellular, systemic pH. There are data to indicate that altered pH is not simply an epiphenomenon of metabolic or physiologic imbalance but that chronic pH alterations can have important sequelae. MRSI and MRI measurements indicate that pH gradients of up to 1.0 pH unit can exit within 1-cm distance. Although measurement of blood pH can indicate systemic problems, it cannot pinpoint the lesion or quantitatively assess the magnitude of excursion from normal pHe. Hence, there is a need to develop pHe measurement methods with high spatiotemporal resolution. The two major approaches being investigated include magnetization transfer methods and relaxation methods. pH-dependent MT effects can observed with endogenous signals or exogenously applied CEST agents. While endogenous signals have the advantage of being fully noninvasive and relatively straightforward to apply, they lack a full biophysical characterization and dynamic range that might be afforded by future CEST agents. pH-dependent relaxivity also requires the injection or infusion of exogenous contrast reagents. In both MT and relaxographic approaches, the magnitude of the effect, and, thus, the ability to quantify pHe, depends on a spatially and temporally varying concentration of the CR. A number of approaches have been proposed to solve this problem and, once it is solved, pH imaging methods will be applicable to human clinical pathologies.

Acid-Base Equilibrium↗
PubMed1997

Derangement of pH homeostasis in the renal papilla: ochratoxin A increases pH in vasa recta blood.

It is reported that ochratoxin A (OTA) impairs urinary acidification by increasing the urinary pH and also increases the intracellular pH in Madin-Darby canine kidney cells. This study was designed to examine whether OTA deranges pH homeostasis in the interstitium (or vasa recta) of the renal papilla. Rats were injected once with OTA (3 micromol/kg body weight) intravenously (acute application) or with OTA (1.25 micromol/kg body weight/day) intraperitoneally for 6 days (subchronic application). We measured the pH values in both the descending and ascending vasa recta blood (VR) in the renal papilla. Both the acute and subchronic applications of OTA led to significant increases in pH values in both descending and ascending VR by 0.4-0.6 pH units. However, no significant increases in pH values in renal arterial and aortic blood in OTA-treated rats were observed. We also examined the pH changes in collecting-duct urine after OTA injection (3 micromol/kg body weight). We found a significant increase in pH values 30 min after OTA injection; this significant elevation of pH values was present during the whole experiment (120 min). The results of this study suggest that OTA deranges pH homeostasis in the interstitium of the renal papilla, in addition to the impairment of urinary acidification.

Animals↗
PubMed1967

Measurement of intracellular pH of skeletal muscle with pH-sensitive glass microelectrodes.

We used three methods to examine the relationship among intracellular pH, transmembrane potential, and extracellular pH. Single-barreled electrodes permitted the determination of resting potential and intracellular pH with a minimum of cellular injury. Double-barreled electrodes, which incorporated a reference as well as a pH-sensitive electrode in a single tip, facilitated the direct measurement of intracellular pH without the interposition of the transmembrane potential. Triple-barreled electrodes permitted measurement of intracellular pH during the controlled hyperpolarization or depolarization of the cell membrane. The results of all three methods were in close agreement and disclosed that the H(+) activity of intracellular and extracellular fluid is in electrochemical equilibrium at any given transmembrane potential. This implies that the determinants of intracellular pH are the transmembrane potential and the blood pH. The actual pH of the normal resting muscle cell is 5.99, as estimated from the normal transmembrane potential and blood pH, or as determined by direct measurements of intracellular pH.

Animals↗
PubMed1994

Cerebrospinal fluid pH and PCO2 rapidly follow arterial blood pH and PCO2 with changes in ventilation.

Changes in ventilatory rate affect arterial blood pH and PCO2 within seconds to minutes, but the corresponding acute changes for cerebrospinal fluid (CSF) pH and PCO2 have been as well documented. Using our previously-described swine model of brain retraction ischemia, we examined changes in arterial and CSF pH and PCO2 with acute changes in ventilation in four animals. Newly developed fluorescent dye technology permitted near-instantaneous recording of CSF pH and PCO2 during acute hyperventilation (end-tidal PCO2 of 20 mm Hg) and acute hypoventilation (end-tidal PCO2 of 50 mm Hg). The Puritan-Bennett 3300 Intra-Arterial Blood Gas Monitor (PB3300) was used with the sensor placed in the CSF in the interhemispheric fissure posterior to the corpus callosum. The following data were gathered at 5, 15, 30, and 60 minutes after the ventilatory change: arterial pH and PCO2, end-tidal CO2, laser-Doppler cerebral blood flow, and CSF pH and PCO2. The baseline (normoventilation) values for arterial and CSF pH and PCO2 in swine were comparable to those in humans: arterial pH 7.44 and PCO2 43 mm Hg; CSF pH 7.31 and PCO2 55 mm Hg. Changes in pH and PCO2 with hyperventilation and hypoventilation occurred rapidly in both arterial blood and CSF. Steady-state values were reached within 15 minutes for hypoventilation, and 30 minutes for hyperventilation. The correlation between arterial and CSF values for both pH and PCO2 at 5, 15, 30, and 60 minutes were all very highly significant (P < 0.001) except for arterial and CSF PCO2 at 5 minutes (P < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Acid-Base Equilibrium↗
PubMed2005

Determination of pH by microfluorometry: intracellular and interstitial pH regulation in developing early-stage fish embryos (Danio rerio).

Microfluorometric techniques were applied in vivo for continuous monitoring of specific acid-base parameters in zebrafish (Danio rerio) embryos during early stages of ontogeny. Dextran-coupled pH-sensitive single-excitation/dual-emission dye SNARF-1 was pressure-injected into individual cells or the interstitial space of 16- to 256-cell embryos, and pH was continuously recorded during subsequent development for time periods of up to 8 h. A novel calibration technique was developed, essentially characterized by in vitro inorganic buffer calibration of the optical system and mathematical post-processing according to the effects of in vivo dye modifiers through a correlation established by direct comparison of optical techniques with pH microelectrodes. This approach results in high accuracy of microfluorometry, comparable with that of pH electrodes, and a recovery only limited by the physical stability of the utilized optical system. Intracellular pH (pHi) in Danio rerio embryos between 1k-cells stage and the end of epiboly was found to be well regulated to a mean value of 7.55+/-0.13 (+/-s.d.), a range distinctly more alkaline than typical values for adult fish but in accordance with embryonic pHi of a few non-fish species shortly after fertilization. Also, interstitial pH (pHint) was significantly higher (8.08+/-0.25) than values for extracellular pH in adult fish. Distributions of HCO3- across membranes and between interstitium and ambient fluid compared with respective potentials strongly suggest that pH in these early stages of ontogeny is already adjusted by active transfer processes. Non-respiratory changes in ambient pH between 7.7 and 8.5 did not significantly affect pHi, a result potentially attributable to low membrane leakage rate or to the potency of active transfer mechanisms. In order to assess the pH regulatory systems more quantitatively, embryos were exposed to ambient changes of carbon dioxide partial pressure (PCO2). The direct impact of PCO2 changes on cell pH was alleviated by cell non-bicarbonate buffering and subsequent rapid, almost complete, compensation by changes in cell [HCO3-] as an expression of transmembrane transfer of acid-base relevant ions. On the basis of these results, we conclude that the regulatory potency of embryonic cells is well developed, is active to resist extensive homoiostatic stress and is efficient to maintain critical metabolism in adverse conditions, even at early stages of ontogeny.

Animals↗
PubMed1992

[Usefulness of a disposable nasogastric tube with a pH sensor--comparison with a class pH electrode].

We evaluated a disposable nasogastric tube with a pH sensor in comparison with an external glass pH electrode with aspiration of gastric contents, continuously. The mean pH value determined by pH sensor was 3.01, and 2.99 by glass pH electrode. There was a good correlation between the two methods (r = 0.91). The agreement between the two methods was especially good when pH less than 5.0. There was a wide scattering in the data when pH greater than 5.1. When the glass pH electrode data were above 5.1, the pH sensor tended to show lower pH values than glass pH electrode.

Electrodes↗
PubMed1991

[The development of an antimony electrode with a built-in thermocouple and a temperature-compensated pH meter for the determination of intramyocardial pH during open-heart surgery].

Myocardial acidosis as reflected in pH measured by a glass (G) electrode during ischemic arrest may adversely affect postoperative cardiac function. However, (G) is slow in response and fragile. We report the development of an antimony electrode (Sb) and a pH meter based on our investigation and the results of their clinical application. As a biological material, CPD blood was chosen and subjected to a series of experiments determine its pH by (Sb) and (G). There was a small (within 0.1), but statistically significant difference in pH between (Sb) and (G). To simulate myocardial cooling during operation, CPD blood was cooled and its pH measured by (Sb) and (G). (Sb) showed significantly different behaviour from (G), i,e, the pH tended to fall with the falling temperature, whereas with (G) it tended to rise as had been previously known. The thermodynamic property of (Sb) was checked in appropriate buffer solutions by varying their temperatures. There was an almost linear correlation between EMF by (Sb) and the temperature of the buffer solutions (1 mV/1 degree C, or 0.017 pH/1 degree C). Accordingly, a pH meter incorporating an electronic circuit compensating for the temperature-depending EMF and a (Sb) with a built-in-thermocouple were constructed. Utilizing the new apparatus, CPD blood was again tested and it was proved that the new electrode and the pH meter worked in similar manner to (G). The new apparatus was applied to a series of measurement of intramyocardial pH during open-heart surgery and the results compared with that previously obtained by (G). There were no significant differences either between control pH or rate of its fall in the initial 10 minutes. following aortic cross-clamping and the administration of the cardioplegic solution. It is concluded that although (Sb) is not as accurate as (G), it is a reasonable alternative for the determination of the intramyocardial pH during open-heart surgery.

Cardiac Surgical Procedures↗
PubMed1985

Influence of the pH of cardioplegic solutions on intracellular pH, high-energy phosphates, and postarrest performance. Protective effects of acidotic, glutamate-containing cardioplegic perfusates.

The common practice of using alkalotic cardioplegic solutions is not supported by experimental evidence. The present study was conducted to assess the effects of varying the pH (7.00, 7.40, and 7.70 at 20 degrees C) of a glutamate-containing cardioplegic solution on intracellular pH, high-energy phosphate content, and postarrest functional recovery and to compare the effects of various buffers (glutamate, bicarbonate, TRIS, and histidine) at a given pH (7.00 and 7.40). Isolated perfused rat hearts were subjected to 2 hours of cardioplegic arrest at 15 degrees C followed by 30 minutes of reperfusion. Intracellular pH and high-energy phosphate content were measured at 4 minute intervals by phosphorus 31 nuclear magnetic resonance spectroscopy. These data were correlated with postischemic recovery of function. There was no significant difference between the intracellular pH values recorded at the end of arrest in the three glutamate-containing groups. However, the acidotic solution (pH 7.00) resulted in better preservation than the alkalotic solution (pH 7.70), as evidenced by a higher creatine phosphate content at the end of arrest (61% +/- 9% of control values versus 30% +/- 9% [mean +/- standard error of the mean], p less than 0.05), a higher adenosine triphosphate content at the end of reperfusion (102% +/- 5% versus 82% +/- 6%, p less than 0.05), and a faster recovery of aortic flow (at 3 minutes of reperfusion, 91% +/- 11% versus 51% +/- 11%, p less than 0.05). Subsequent comparison of buffers showed that bicarbonate, TRIS, and histidine were equally effective in maintaining intracellular pH close to control values during arrest. Conversely, the use of glutamate resulted in a more pronounced fall in intracellular pH, which correlated with a better preservation of adenosine triphosphate and a better functional recovery than in the other groups. Overall, the greatest extent of preservation was provided by the pH 7.00 glutamate-containing cardioplegic solution. We conclude that additional protection can be conferred to the cold, chemically arrested heart by combining mild intracellular acidosis, which lowers metabolic needs during arrest, most likely through a limitation of calcium overload, and provision of glutamate, which may act as a substrate for anaerobic energy production while allowing intracellular pH to be kept within the appropriate range.

Adenosine Triphosphate↗
PubMed1988

Effects of chronic pH 6.6 on growth, intracellular pH, and response to 42.0 degrees C hyperthermia of Chinese hamster ovary cells.

Culturing Chinese hamster ovary cells in low pH (6.6) medium for several months altered the reproductive survival of these cells to combined low pH treatments and 42.0 degrees C heating. We isolated new pH-resistant cells (identified as pHV-2) with enhanced ability to grow and divide under a low pH (6.6) environment. Their growth characteristics include (a) a plating efficiency of 70%, (b) a doubling time of 16 to 17 h, and (c) a steady state intracellular pH 0.12 pH units higher than for cells grown at a normal pH of 7.3. The pHV-2 cells had 100- to 200-fold increases in survival after 5 h of heating compared to cells incubated at low pH (6.6) for 4 h prior to and during the heat treatments. In addition, they developed a significant degree of thermotolerance. We measured a progressive decline in the intracellular pH as a function of time at 42.0 degrees C. However, the decrease in the intracellular pH did not seem to be correlated with the increased heat sensitivity. The ability to select for low pH variants may have important implications in the extrapolation of in vitro hyperthermic data to the in vivo situation.

Animals↗
PubMed1988

Development of thermotolerance and changes in intracellular pH in CHO cells heated at 45.0 degrees C at pH 6.6.

Chinese hamster ovary (CHO) cells were given short heat pulses (5 to 20 min) at 45.0 degrees C and incubated at 37 degrees C for up to 20 h under either pH 7.3 or 6.6 conditions. Thermotolerance developed under both pH conditions, but at a slower rate in the pH 6.6 medium. Intracellular pH (pHi) was measured with the dye, 1,4-diacetoxy-2,3-dicyanobenzene, combined with flow cytometry. Time-dependent changes in the intracellular pH occurred under either pH condition. CHO cells incubated under normal pH conditions had a transient increase in the pHi. This pHi elevation was followed by a rapid intracellular acidification of approximately 0.15 to 0.25 pH units. The timing of both the increases and decreases in the pHi was dependent on the magnitude of the initial heat dose. With heat doses less than or equal to 10 min, the pHi returned to normal unheated levels after the acidification phase. Although cells incubated under low pH (6.6) conditions showed similar pHi alterations, differences in the kinetics were measured. The intracellular pH increased immediately after heating. In addition, when intracellular acidification occurred, the rate of acidification was significantly reduced. With heat doses longer than 5 min under the low pH conditions, the pHi did not return to normal unheated levels.

Animals↗
PubMed1986

Maternal-fetal pH difference and fetal scalp pH as predictors of neonatal outcome.

The purpose of this study was to determine if interpretation of fetal scalp pH values would be enhanced by concurrent measurement of maternal venous pH. The last fetal capillary pH obtained before delivery was compared with simultaneous maternal-fetal pH difference as predictors of neonatal outcome assessed by five-minute Apgar scores. Fetal scalp pH and maternal-fetal pH difference were significantly correlated with r = -0.72 (P less than .0001). The acidotic fetuses born to acidotic mothers had low maternal-fetal pH differences, and all were nondepressed at birth. A 33% reduction in false negatives was found using maternal-fetal pH difference instead of scalp pH alone. Errors in interpretation of fetal scalp pH can be reduced by the use of maternal-fetal pH difference.

Apgar Score↗
PubMed1993

[Cytogenetic and molecular studies in patients with chronic myelogenous leukemia without Ph chromosome and with unusual Ph translocation].

Cytogenetic and molecular studies were made in 4 patients with Ph negative chronic myelogenous leukemia (CML) and 4 patients with CML with unusual Ph translocation. Chromosome analysis was performed on direct preparations and short-term cultures of bone marrow cells by R and G bandings. Southern blot analysis of DNA from leukemia cells was made using 4.5kb bcr-u and 1.5kb bcr-HE probes. Four patients with Ph negative CML had normal karyotypes. Among them, 3 had rearrangement of bcr, and 1 expected germ line pattern only. In the 4 patients with CML with unusual Ph translocation who had bcr rearrangement, one had a masked Ph chromosome originating from a translocation t(3;22) (p22;q11), the other three had one of the following complex Ph translocations: t(9;22;13) (q34;q11;q21), t(3;14;22) (p21;q32;q11) and t(X;9;22;12) (q22; q34; q11; q24). Our data confirmed that Ph negative CML could be divided into two different subsets: Ph-bcr+ CML and Ph-bcr-CML and that whatever the type of translocation may be, CML with unusual Ph translocation and Ph positive CML had a common molecular pathological basis.

Adult↗
PubMed2006

Acid reflux immediately above the squamocolumnar junction and in the distal esophagus: simultaneous pH monitoring using the wireless capsule pH system.

OBJECTIVES: The pattern of reflux in the most distal esophagus of asymptomatic individuals is largely unknown. Using a wireless technique we compared the degree and the pattern of acid reflux just above the squamocolumnar junction (SCJ) with that measured at the conventional level for pH monitoring. METHODS: Fifty-three asymptomatic volunteers underwent endoscopy with transoral placement of two pH recording capsules, one immediately above and one 6 cm above the SCJ. Ambulatory pH monitoring was performed during 48 h. RESULTS: Three subjects were excluded as the distal capsule was inadvertently placed with the pH electrode below the SCJ. The median percent time with pH < 4 and the median number of reflux episodes were significantly higher immediately above the SCJ compared with that found more proximally (1.6%vs 0.9% and 67 vs 26, p < 0.0001). Of all acid reflux events, 69% were isolated episodes immediately above the SCJ. Only 26% of reflux episodes detected at the SCJ extended to the more proximal pH electrode. Reflux events occurring just above the SCJ were more acidic. The number of reflux events with a minimum pH below 2 or 3 was significantly higher at the SCJ compared with that recorded by the upper capsule (16% and 44%vs 6% and 34%, p < 0.0001). CONCLUSIONS: Conventional pH monitoring substantially underestimates the degree of acid exposure in the most distal esophagus. In healthy subjects, acid exposure immediately above the SCJ was considerably higher and was characterized by shorter reflux episodes that had a lower minimum pH compared with that measured at the traditional level for pH monitoring.

Adult↗
PubMed2005

On-line monitoring of CO2 production in Lactococcus lactis during physiological pH decrease using membrane inlet mass spectrometry with dynamic pH calibration.

Monitoring CO2 production in systems, where pH is changing with time is hampered by the chemical behavior and pH-dependent volatility of this compound. In this article, we present the first method where the concentration and production rate of dissolved CO2 can be monitored directly, continuously, and quantitatively under conditions where pH changes rapidly ( approximately 2 units in 15 min). The method corrects membrane inlet mass spectrometry (MIMS) measurements of CO2 for pH dependency using on-line pH analysis and an experimentally established calibration model. It is valid within the pH range of 3.5 to 7, despite pH-dependent calibration constants that vary in a non-linear fashion with more than a factor of 3 in this interval. The method made it possible to determine the carbon dioxide production during Lactococcus lactis fermentations, where pH drops up to 3 units during the fermentation. The accuracy was approximately 5%. We used the method to investigate the effect of initial extracellular pH on carbon dioxide production during anarobic glucose fermentation by non-growing Lactocoocus lactis and demonstrated that the carbon dioxide production rate increases considerably, when the initial pH was increased from 6 to 6.8.

Calibration↗
PubMed1998

Amperometric pH regulation--a flexible tool for rapid and precise temporal control over the pH of an electrolyte solution.

Temporal control over both pH and ionic strength of an electrolyte solution with high accuracy was achieved with a dynamic, computer feedback-controlled amperometric pH-stat device consisting of four pH-regulating electrodes placed in electrolyte reservoirs that are separated by dialysis membranes from a central compartment. Theoretical predictions of the behavior of this arrangement, obtained by computer simulation, were validated by running temporal pH programs such as step functions, oscillations, and linear pH gradients. Deviations from nominal values given by the computer program are within the limits of accuracy of the pH-measuring electrodes. No volume changes accompany a change of pH or conductivity since ions are forced to leave or enter the central compartment through the membranes by the electrical force applied between the pH-regulating electrodes. The device is flexible, easy to use and easily miniaturized. We discuss a wide range of possible applications in biochemistry and cell science. These include automated pH adjustment, isoelectric protein separation, amperometric measurement of enzyme kinetics and the response of cell cultures to well-defined pH changes.

Computer Simulation↗
PubMed2006

High resolution pH(e) imaging of rat glioma using pH-dependent relaxivity.

Previous studies using MR spectroscopy have shown that the extracellular pH (pH(e)) of tumors is acidic compared to normal tissues. This has a number of important sequelae that favor the emergence of more aggressive and therapy-resistant tumors. New MRI methods based on pH-sensitive T1 relaxivity are an attractive alternative to previous spectroscopic methods, as they allow improvements in spatial and temporal resolution. Recently, pH-dependent GdDOTA-4AmP5- and a pH-independent analog, GdDOTP5-, were used to image renal pH in mice. The current study has used a similar approach to image pH(e) in rat gliomas. Significant differences were observed compared to the renal study. First, the relaxivity of GdDOTP5- was found to be affected by the higher extracellular protein content of tumors. Second, the pixel-by-pixel analysis of the GdDOTP5- and GdDOTA-4AmP5- pharmacokinetics showed significant dispersion, likely due to the temporal fluctuations in tumor perfusion. However, there was a robust correlation between the maximal enhancements produced by the two boluses. Therefore, to account for the local time-courses differences, pH(e) maps were calculated at the time of maximal enhancement in each pixel. Finally, the comparison of the pH(e) and the time to maximal intensity maps revealed an inverse relationship between pH(e) and tumor perfusion.

Analysis of Variance↗