Vetury Sitaramam | University of Pune (original) (raw)
Papers by Vetury Sitaramam
Assessment in schools is restricted to year-end or course-end tests that demand cramming which do... more Assessment in schools is restricted to year-end or course-end tests that demand cramming which does not reflect true learning. The performance in these year-end examinations is skewed by socio-economic factors, besides the psychological stress induced and the resultant, unacceptable malpractices. Long term retention of school learning has not been recognized and developed into a viable alternative to assess what has been grasped by the student. We developed a quantitative design for a rapidly deployable test for long term retention as a viable alternative to assess true learning for the first time. While the data demonstrates drastic falling of retention with years of schooling towards more recent years, it has unique attributes depending on the subjects taught, independent of socioeconomic circumstances and gender, not apparent from the usual school tests. What has been learnt cannot be independent of what was taught and by whom and thus the test holds promise to assess the teacher...
PDBe › 3m3u. Effect of temperature on tryptophan fluorescence in lysozyme crystals., 2010
Whistler, the painter who saw it fit paint his elderly ‘mother’, was well known also for his wit... more Whistler, the painter who saw it fit paint his elderly ‘mother’, was well known also for his
wit. Once, appreciative of his particularly witty remark, (Lord) Byron remarked, “I wish
I said that”. Whistler sardonically replied, “ You will, you will”. So much was written
about plagiarism, honesty, values etc. in these columns that smacks of the “ol’ time
religion…”. Self-appointed societies rushing at the windmills of scientific compulsions
quixotically, committees after committees implicating and exonerating individuals in an
endless pursuit of the zero sum game, leaving the public at a totally confused state amidst a welter of accusations and counteraccusations….all this to what end? Is all this self hypnosis based on presumptive action? Actually, is plagiarism all that bad? Who or what is hurt? Let he who has not sinned be the first to throw a stone!
J. Sci. Ind. Res. India. 47, 395 - 403, l988.
Journal of Applied Physiology, 1975
The activity of hepatic tryptophan pyrrolase in rats exposed to cold increased rapidly and reache... more The activity of hepatic tryptophan pyrrolase in rats exposed to cold increased rapidly and reached a maximum of three-fold at 8 h. On continued exposure up to 48 h stress, the activity partly decreased but remained at a level higher than the initial. Withdrawal from the cold stress reversed the change. Adrenalectomy or treatment with inhibitors of protein synthesis abolished the increase in the enzyme activity during cold stress indicating a possible involvement of corticosteroids and de novo protein synthesis. Treatment with drugs known to block autonomic nervous system failed to inhibit the cold-mediated increase in enzyme activity. The results suggest that the increase in enzyme activity obtained on cold exposure is mediated by corticosteroids and not by either indoleaklylamines or autonomic nervous system. The changes in the enzyme obtained under cold stress with respect to the overshoot phenomenon, relationship to the degree of stress and reversibility on withdrawal from the st...
FEBS Letters, 1989
The physical properties of amino acids were investigated in order to evaluate their possible rela... more The physical properties of amino acids were investigated in order to evaluate their possible relationship to the assignment of codons for amino acids in the genetic code. A comparison of the interconversion probability between amino acids and the distances between the amino acids for individual physical properties revealed a striking hierarchy among the physical properties. Surprisingly, it is the long-range/solvent interactions and not the short-range/stereochemical properties which are preferentially conserved in the genetic code. Physical properties; Frozen accident; Stereochemical hypothesis/fluctuation
Biophysical Chemistry, 2001
Polymeric structures, namely, micelles, membranes and globular proteins share the property of two... more Polymeric structures, namely, micelles, membranes and globular proteins share the property of two distinct regions: a hydrophobic core and a hydrophilic exterior. The dynamics of these regions of the polymeric structures were probed using selective fluorophores 1,6-diphenyl-1,3,5-hexatriene (DPH) and 1-anilinonaphthalene-8-sulfonate (ANS), respectively. Perturbation of the polymers by external osmotic pressure, ionic strength and temperature was monitored in the two regions using steady state measurements of fluorescence intensity and anisotropy. While the fluorescence lifetime of DPH and ANS did not change significantly, parallel change in steady state anisotropy values and the rotational correlation time indicated mobility in the probe/probe-domain. Osmotic perturbation of the polymers in electrolyte media led to decreased DPH mobility. Enhanced ellipticity at 222 nm in bovine serum albumin was observed in 1.5 M NaCl and sucrose media. ANS exhibited a decreased anisotropy with progressive dehydration in proteins in NaCl media, in dimyristoylphosphatidylcholine (DMPC) vesicles in sucrose media, and in neutral laurylmaltoside micelles in both NaCl and sucrose media. Thus, ANS showed responses opposite to that of DPH in these systems. A comparison with several domain selective probes indicated that DPH reported findings common to depth probes while ANS reported data common to interfacial probes used for voltage monitoring.
Biochimica et Biophysica Acta (BBA) - Biomembranes, 1996
The role of the permeability barrier of the outer membrane of Pseudomonas was re-evaluated based ... more The role of the permeability barrier of the outer membrane of Pseudomonas was re-evaluated based on the physical theory of molecular sieving in view of its intrinsic antibiotic resistance. We developed a set of analytical procedures based on parametric and non-parametric statistical tests to evaluate, validate and adopt the better among a set of competing non-linear models of diffusion. The molecular mass dependence of uptake of non-electrolytes in bacteria yielded a quantitative measure to distinguish between sieving mechanisms and specific uptake/effiux mechanisms. The experimental data, supported by the physical model of DEAE-Sephadex and various analytical models and extensive simulation of the errors, both in measurement and models, yielded evidence consistent with the relaxation of the outer membrane matrix barrier in Pseudomonas.
Molecular Reproduction and Development, 1997
Bovine spermatozoa were shown to exhibit rapid regulatory volume decrease (RVD) when exposed to... more Bovine spermatozoa were shown
to exhibit rapid regulatory volume decrease (RVD) when
exposed to hypotonic saline media. This quinine- and
quinidine-sensitive regulatory volume decrease was
coincident with K1 release due to stretch-activation of
inhibitor-specific presumptive K1 channels. The regulatory
volume decrease response was much faster than a
similar phenomenon observed in human peripheral
blood lymphocytes. Studies on volume changes in
different electrolyte and nonelectrolyte media suggested
that: (1) this inhibitor-specific channel could also
be a nonspecific pore in the spermatozoal membrane
for nonelectrolytes below 150 daltons; (2) subpopulations
(of nearly equal size) of the spermatozoa differ in
the expression of the pore; (3) capacitation abolishes
this distinction between subpopulations of spermatozoa;
and (4) the general case of RVD for other mammalian
spermatozoa was also established. Mol. Reprod.
Dev. 46:535–550, 1997. r 1997 Wiley-Liss, Inc.
Frontiers in Plant Science
The biological improvement of fertilizer nitrogen use efficiency (NUE) is hampered by the poor ch... more The biological improvement of fertilizer nitrogen use efficiency (NUE) is hampered by the poor characterization of the phenotype and genotype for crop N response and NUE. In an attempt to identify phenotypic traits for N-response and NUE in the earliest stages of plant growth, we analyzed the N-responsive germination, respiration, urease activities, and root/shoot growth of 21 Indica genotypes of rice (Oryza sativa var. indica). We found that N delays germination from 0 to 12 h in a genotype-dependent and sourcedependent manner, especially with urea and nitrate. We identified contrasting groups of fast germinating genotypes such as Aditya, Nidhi, and Swarnadhan, which were also least delayed by N and slow germinating genotypes such as Panvel 1, Triguna, and Vikramarya, which were also most delayed by N. Oxygen uptake measurements in the seeds of contrasting genotypes revealed that they were affected by N source in accordance with germination rates, especially with urea. Germinating seeds were found to have endogenous urease activity, indicating the need to explore genotypic differences in the effective urea uptake and metabolism, which remain unexplored so far. Urea was found to significantly inhibit early root growth in all genotypes but not shoot growth. Field evaluation of 15 of the above genotypes clearly showed that germination rates, crop duration, and yield are linked to NUE. Slow germinating genotypes had longer crop duration and higher yield even at lower N, indicating their higher NUE, relative to fast germinating or short duration genotypes. Moreover, longer duration genotypes suffered lesser yield losses at reduced N levels as compared to short duration genotypes, which is also a measure of their NUE. Together, these results indicate the potential of germination rates, crop duration, urea utilization and its effect on root growth in the development of novel phenotypic traits for screening genotypes and crop improvement for NUE, at least in rice.
Frontiers in Plant Science
Crop improvement for Nitrogen Use Efficiency (NUE) requires a well-defined phenotype and genotype... more Crop improvement for Nitrogen Use Efficiency (NUE) requires a well-defined phenotype and genotype, especially for different N-forms. As N-supply enhances growth, we comprehensively evaluated 25 commonly measured phenotypic parameters for N response using 4 N treatments in six indica rice genotypes. For this, 32 replicate potted plants were grown in the green-house on nutrient-depleted sand. They were fertilized to saturation with media containing either nitrate or urea as the sole N source at normal (15 mM N) or low level (1.5 mM N). The variation in N-response among genotypes differed by N form/dose and increased developmentally from vegetative to reproductive parameters. This indicates survival adaptation by reinforcing variation in every generation. Principal component analysis segregated vegetative parameters from reproduction and germination. Analysis of variance revealed that relative to low level, normal N facilitated germination, flowering and vegetative growth but limited y...
Income/expenditures, individual expenditures such as education, and performance in schools all re... more Income/expenditures, individual expenditures such as education, and performance in schools all relate to systems with defined inputs and outputs and have been formally modeled in accordance with a systems theoretic approach. The Engel’s curves of expenditures on commodities from the Indian National Sample Survey Organization data was hyperbolic limited by a perceived ‘time constant’ associated with commodities while the preferences themselves are ordered hierarchically. School participation (dropouts) as a function of parental income based on available Brazilian data also shows a hierarchical hyperbolic relationship, thereby proving the nature of hierarchy in a naturally ordinal commodity - education. Since the socio-economic influences skew school performance in year-end examinations that demand cramming, retention over the years was tested in a school with a small cross section of 9th grade students uniformly distributed for their previous year’s school grades. The startling findi...
The study focuses quantitatively on ways to assess school education, currently under severe criti... more The study focuses quantitatively on ways to assess school education, currently under severe criticism, in terms the first of its three major components, students, teachers and curriculum,. We developed a novel method to assess long term retention as a measure of true learning in tests that do not involve any cramming and found to our dismay that it falls progressively more towards recent years. Our initial work on poverty showed that consumption on commodities is hyperbolic (as in catalysis) and hierarchic and, that the total income is not fractionally distributed among the commodities, as economists assume; the leftover (residual) income after the more essential items is spent on the commodities of lesser preference. Education is also a naturally ordered commodity and parental income quantitatively determined school dropouts/attendance obeying the same hyperbolic relationship, as we could show. We could thereby affirm the first-ever mechanism for Engels’ three curves of consumption...
Some degree of conceptualization would clearly occur during past traditional learning even if not... more Some degree of conceptualization would clearly occur during past traditional learning even if not formally realized as concept maps, since conceptual connectivity and progression are intuitively grasped. Can this be measured? The methodology for developing metrics for the ‘solidness’ of past learning has major prospects in the development of educational strategies, as retained learning alone can be true learning; it sheds light on ‘the disconnects’ that throw learning off-gear, when evaluated at a mass level. Here, we outline such a methodology that tantamounts to sleuthing for limits to true learning both in an individual and a group that the practitioners of concept maps may find useful, by reexamining for retention of past learning. Quantitation in retention together with concept maps complete the loop of learning, offering invaluable feedback where it is needed most, i.e., blind spots in learning.
Indian journal of experimental biology
Cancer Research
The circulating level of a novel RNA-proteolipid complex associated with malignant diseases was c... more The circulating level of a novel RNA-proteolipid complex associated with malignant diseases was critically evaluated as a tumor marker in clinical oncology. The complex, isolated from the sera of cancer patients, exhibited unvarying chemical composition regardless of the cell type and clinical staging. Clearance from blood was rapid with a half-life of approximately 2 days. Tumor mass could be correlated with the circulat ing level. After effective treatment the level fell and rose again 10 months prior to the conventional clinical diagnosis of relapse.
Journal of Theoretical Biology, 1998
Dynamic states of biopolymers are associated with appearance and disappearance of spaces, or void... more Dynamic states of biopolymers are associated with appearance and disappearance of spaces, or voids, to an extent larger than what is hitherto recognized. Current awareness of the existence of free space in biopolymers is by and large restricted in terms of (i) essentially small pores obeying Boltzman distribution of sizes and energy and (ii) rigid structures dictated by structural constraints, whose volume merely exhibits fluctuations within the thermal limits. Interconnectivity of these spaces within biopolymers such as membranes give rises to new possibilities in addressing some of the long standing problems in understanding catalysis, transport and the derived biological phenomena. Given the a priori recognition that other kinds of space can exist in biopolymers, which are dynamic, predominantly inducible and possibly larger, a new kind of experimentation becomes possible as also a new set of constraints for the acceptability of molecular models of interactions in the explanation of biological phenomena. The theory of adsorption of liquids and presence of structural cavities as exemplified by zeolites competently accounts for much of the current thinking in our understanding of cavities in biopolymers. Induction of (larger) voids requires approaches that are significantly different. We suggest that it is necessary to consider a reservoir of inner space as a specific contribution to the energetics of polymer dynamics. We outline a methodological approach that helps identify these voids as well as biological phenomena in which the notion of dynamics of voids would bring novel insights. Copyright 1998 Academic Press
Assessment in schools is restricted to year-end or course-end tests that demand cramming which do... more Assessment in schools is restricted to year-end or course-end tests that demand cramming which does not reflect true learning. The performance in these year-end examinations is skewed by socio-economic factors, besides the psychological stress induced and the resultant, unacceptable malpractices. Long term retention of school learning has not been recognized and developed into a viable alternative to assess what has been grasped by the student. We developed a quantitative design for a rapidly deployable test for long term retention as a viable alternative to assess true learning for the first time. While the data demonstrates drastic falling of retention with years of schooling towards more recent years, it has unique attributes depending on the subjects taught, independent of socioeconomic circumstances and gender, not apparent from the usual school tests. What has been learnt cannot be independent of what was taught and by whom and thus the test holds promise to assess the teacher...
PDBe › 3m3u. Effect of temperature on tryptophan fluorescence in lysozyme crystals., 2010
Whistler, the painter who saw it fit paint his elderly ‘mother’, was well known also for his wit... more Whistler, the painter who saw it fit paint his elderly ‘mother’, was well known also for his
wit. Once, appreciative of his particularly witty remark, (Lord) Byron remarked, “I wish
I said that”. Whistler sardonically replied, “ You will, you will”. So much was written
about plagiarism, honesty, values etc. in these columns that smacks of the “ol’ time
religion…”. Self-appointed societies rushing at the windmills of scientific compulsions
quixotically, committees after committees implicating and exonerating individuals in an
endless pursuit of the zero sum game, leaving the public at a totally confused state amidst a welter of accusations and counteraccusations….all this to what end? Is all this self hypnosis based on presumptive action? Actually, is plagiarism all that bad? Who or what is hurt? Let he who has not sinned be the first to throw a stone!
J. Sci. Ind. Res. India. 47, 395 - 403, l988.
Journal of Applied Physiology, 1975
The activity of hepatic tryptophan pyrrolase in rats exposed to cold increased rapidly and reache... more The activity of hepatic tryptophan pyrrolase in rats exposed to cold increased rapidly and reached a maximum of three-fold at 8 h. On continued exposure up to 48 h stress, the activity partly decreased but remained at a level higher than the initial. Withdrawal from the cold stress reversed the change. Adrenalectomy or treatment with inhibitors of protein synthesis abolished the increase in the enzyme activity during cold stress indicating a possible involvement of corticosteroids and de novo protein synthesis. Treatment with drugs known to block autonomic nervous system failed to inhibit the cold-mediated increase in enzyme activity. The results suggest that the increase in enzyme activity obtained on cold exposure is mediated by corticosteroids and not by either indoleaklylamines or autonomic nervous system. The changes in the enzyme obtained under cold stress with respect to the overshoot phenomenon, relationship to the degree of stress and reversibility on withdrawal from the st...
FEBS Letters, 1989
The physical properties of amino acids were investigated in order to evaluate their possible rela... more The physical properties of amino acids were investigated in order to evaluate their possible relationship to the assignment of codons for amino acids in the genetic code. A comparison of the interconversion probability between amino acids and the distances between the amino acids for individual physical properties revealed a striking hierarchy among the physical properties. Surprisingly, it is the long-range/solvent interactions and not the short-range/stereochemical properties which are preferentially conserved in the genetic code. Physical properties; Frozen accident; Stereochemical hypothesis/fluctuation
Biophysical Chemistry, 2001
Polymeric structures, namely, micelles, membranes and globular proteins share the property of two... more Polymeric structures, namely, micelles, membranes and globular proteins share the property of two distinct regions: a hydrophobic core and a hydrophilic exterior. The dynamics of these regions of the polymeric structures were probed using selective fluorophores 1,6-diphenyl-1,3,5-hexatriene (DPH) and 1-anilinonaphthalene-8-sulfonate (ANS), respectively. Perturbation of the polymers by external osmotic pressure, ionic strength and temperature was monitored in the two regions using steady state measurements of fluorescence intensity and anisotropy. While the fluorescence lifetime of DPH and ANS did not change significantly, parallel change in steady state anisotropy values and the rotational correlation time indicated mobility in the probe/probe-domain. Osmotic perturbation of the polymers in electrolyte media led to decreased DPH mobility. Enhanced ellipticity at 222 nm in bovine serum albumin was observed in 1.5 M NaCl and sucrose media. ANS exhibited a decreased anisotropy with progressive dehydration in proteins in NaCl media, in dimyristoylphosphatidylcholine (DMPC) vesicles in sucrose media, and in neutral laurylmaltoside micelles in both NaCl and sucrose media. Thus, ANS showed responses opposite to that of DPH in these systems. A comparison with several domain selective probes indicated that DPH reported findings common to depth probes while ANS reported data common to interfacial probes used for voltage monitoring.
Biochimica et Biophysica Acta (BBA) - Biomembranes, 1996
The role of the permeability barrier of the outer membrane of Pseudomonas was re-evaluated based ... more The role of the permeability barrier of the outer membrane of Pseudomonas was re-evaluated based on the physical theory of molecular sieving in view of its intrinsic antibiotic resistance. We developed a set of analytical procedures based on parametric and non-parametric statistical tests to evaluate, validate and adopt the better among a set of competing non-linear models of diffusion. The molecular mass dependence of uptake of non-electrolytes in bacteria yielded a quantitative measure to distinguish between sieving mechanisms and specific uptake/effiux mechanisms. The experimental data, supported by the physical model of DEAE-Sephadex and various analytical models and extensive simulation of the errors, both in measurement and models, yielded evidence consistent with the relaxation of the outer membrane matrix barrier in Pseudomonas.
Molecular Reproduction and Development, 1997
Bovine spermatozoa were shown to exhibit rapid regulatory volume decrease (RVD) when exposed to... more Bovine spermatozoa were shown
to exhibit rapid regulatory volume decrease (RVD) when
exposed to hypotonic saline media. This quinine- and
quinidine-sensitive regulatory volume decrease was
coincident with K1 release due to stretch-activation of
inhibitor-specific presumptive K1 channels. The regulatory
volume decrease response was much faster than a
similar phenomenon observed in human peripheral
blood lymphocytes. Studies on volume changes in
different electrolyte and nonelectrolyte media suggested
that: (1) this inhibitor-specific channel could also
be a nonspecific pore in the spermatozoal membrane
for nonelectrolytes below 150 daltons; (2) subpopulations
(of nearly equal size) of the spermatozoa differ in
the expression of the pore; (3) capacitation abolishes
this distinction between subpopulations of spermatozoa;
and (4) the general case of RVD for other mammalian
spermatozoa was also established. Mol. Reprod.
Dev. 46:535–550, 1997. r 1997 Wiley-Liss, Inc.
Frontiers in Plant Science
The biological improvement of fertilizer nitrogen use efficiency (NUE) is hampered by the poor ch... more The biological improvement of fertilizer nitrogen use efficiency (NUE) is hampered by the poor characterization of the phenotype and genotype for crop N response and NUE. In an attempt to identify phenotypic traits for N-response and NUE in the earliest stages of plant growth, we analyzed the N-responsive germination, respiration, urease activities, and root/shoot growth of 21 Indica genotypes of rice (Oryza sativa var. indica). We found that N delays germination from 0 to 12 h in a genotype-dependent and sourcedependent manner, especially with urea and nitrate. We identified contrasting groups of fast germinating genotypes such as Aditya, Nidhi, and Swarnadhan, which were also least delayed by N and slow germinating genotypes such as Panvel 1, Triguna, and Vikramarya, which were also most delayed by N. Oxygen uptake measurements in the seeds of contrasting genotypes revealed that they were affected by N source in accordance with germination rates, especially with urea. Germinating seeds were found to have endogenous urease activity, indicating the need to explore genotypic differences in the effective urea uptake and metabolism, which remain unexplored so far. Urea was found to significantly inhibit early root growth in all genotypes but not shoot growth. Field evaluation of 15 of the above genotypes clearly showed that germination rates, crop duration, and yield are linked to NUE. Slow germinating genotypes had longer crop duration and higher yield even at lower N, indicating their higher NUE, relative to fast germinating or short duration genotypes. Moreover, longer duration genotypes suffered lesser yield losses at reduced N levels as compared to short duration genotypes, which is also a measure of their NUE. Together, these results indicate the potential of germination rates, crop duration, urea utilization and its effect on root growth in the development of novel phenotypic traits for screening genotypes and crop improvement for NUE, at least in rice.
Frontiers in Plant Science
Crop improvement for Nitrogen Use Efficiency (NUE) requires a well-defined phenotype and genotype... more Crop improvement for Nitrogen Use Efficiency (NUE) requires a well-defined phenotype and genotype, especially for different N-forms. As N-supply enhances growth, we comprehensively evaluated 25 commonly measured phenotypic parameters for N response using 4 N treatments in six indica rice genotypes. For this, 32 replicate potted plants were grown in the green-house on nutrient-depleted sand. They were fertilized to saturation with media containing either nitrate or urea as the sole N source at normal (15 mM N) or low level (1.5 mM N). The variation in N-response among genotypes differed by N form/dose and increased developmentally from vegetative to reproductive parameters. This indicates survival adaptation by reinforcing variation in every generation. Principal component analysis segregated vegetative parameters from reproduction and germination. Analysis of variance revealed that relative to low level, normal N facilitated germination, flowering and vegetative growth but limited y...
Income/expenditures, individual expenditures such as education, and performance in schools all re... more Income/expenditures, individual expenditures such as education, and performance in schools all relate to systems with defined inputs and outputs and have been formally modeled in accordance with a systems theoretic approach. The Engel’s curves of expenditures on commodities from the Indian National Sample Survey Organization data was hyperbolic limited by a perceived ‘time constant’ associated with commodities while the preferences themselves are ordered hierarchically. School participation (dropouts) as a function of parental income based on available Brazilian data also shows a hierarchical hyperbolic relationship, thereby proving the nature of hierarchy in a naturally ordinal commodity - education. Since the socio-economic influences skew school performance in year-end examinations that demand cramming, retention over the years was tested in a school with a small cross section of 9th grade students uniformly distributed for their previous year’s school grades. The startling findi...
The study focuses quantitatively on ways to assess school education, currently under severe criti... more The study focuses quantitatively on ways to assess school education, currently under severe criticism, in terms the first of its three major components, students, teachers and curriculum,. We developed a novel method to assess long term retention as a measure of true learning in tests that do not involve any cramming and found to our dismay that it falls progressively more towards recent years. Our initial work on poverty showed that consumption on commodities is hyperbolic (as in catalysis) and hierarchic and, that the total income is not fractionally distributed among the commodities, as economists assume; the leftover (residual) income after the more essential items is spent on the commodities of lesser preference. Education is also a naturally ordered commodity and parental income quantitatively determined school dropouts/attendance obeying the same hyperbolic relationship, as we could show. We could thereby affirm the first-ever mechanism for Engels’ three curves of consumption...
Some degree of conceptualization would clearly occur during past traditional learning even if not... more Some degree of conceptualization would clearly occur during past traditional learning even if not formally realized as concept maps, since conceptual connectivity and progression are intuitively grasped. Can this be measured? The methodology for developing metrics for the ‘solidness’ of past learning has major prospects in the development of educational strategies, as retained learning alone can be true learning; it sheds light on ‘the disconnects’ that throw learning off-gear, when evaluated at a mass level. Here, we outline such a methodology that tantamounts to sleuthing for limits to true learning both in an individual and a group that the practitioners of concept maps may find useful, by reexamining for retention of past learning. Quantitation in retention together with concept maps complete the loop of learning, offering invaluable feedback where it is needed most, i.e., blind spots in learning.
Indian journal of experimental biology
Cancer Research
The circulating level of a novel RNA-proteolipid complex associated with malignant diseases was c... more The circulating level of a novel RNA-proteolipid complex associated with malignant diseases was critically evaluated as a tumor marker in clinical oncology. The complex, isolated from the sera of cancer patients, exhibited unvarying chemical composition regardless of the cell type and clinical staging. Clearance from blood was rapid with a half-life of approximately 2 days. Tumor mass could be correlated with the circulat ing level. After effective treatment the level fell and rose again 10 months prior to the conventional clinical diagnosis of relapse.
Journal of Theoretical Biology, 1998
Dynamic states of biopolymers are associated with appearance and disappearance of spaces, or void... more Dynamic states of biopolymers are associated with appearance and disappearance of spaces, or voids, to an extent larger than what is hitherto recognized. Current awareness of the existence of free space in biopolymers is by and large restricted in terms of (i) essentially small pores obeying Boltzman distribution of sizes and energy and (ii) rigid structures dictated by structural constraints, whose volume merely exhibits fluctuations within the thermal limits. Interconnectivity of these spaces within biopolymers such as membranes give rises to new possibilities in addressing some of the long standing problems in understanding catalysis, transport and the derived biological phenomena. Given the a priori recognition that other kinds of space can exist in biopolymers, which are dynamic, predominantly inducible and possibly larger, a new kind of experimentation becomes possible as also a new set of constraints for the acceptability of molecular models of interactions in the explanation of biological phenomena. The theory of adsorption of liquids and presence of structural cavities as exemplified by zeolites competently accounts for much of the current thinking in our understanding of cavities in biopolymers. Induction of (larger) voids requires approaches that are significantly different. We suggest that it is necessary to consider a reservoir of inner space as a specific contribution to the energetics of polymer dynamics. We outline a methodological approach that helps identify these voids as well as biological phenomena in which the notion of dynamics of voids would bring novel insights. Copyright 1998 Academic Press