Showing papers by "La Trobe University published in 1974"
TL;DR: The estimated ϵ205 is about three times better than using an average ϵ2051 mg/ml of 31 and approaches the range of experimental error inherent in any method of protein estimation.
688 citations
TL;DR: The retarding potential analyzer aboard Ogo 6 has provided high-resolution observations of the ion concentration along the satellite path as mentioned in this paper, and the most common frequency spectrum observed suggests that the responsible irregularities result from the turbulent dissipation of larger irregularities.
Abstract: The retarding potential analyzer aboard Ogo 6 has provided high-resolution observations of the ion concentration along the satellite path. Changes in ion concentration as small as 0.03% and at times as small as 0.01% could be measured. Spatial resolution varied from 35 to 380 m. Samples of data have been analyzed to determine the spectral properties of the F region irregularities observed. The most common frequency spectrum observed suggests that the responsible irregularities result from the turbulent dissipation of larger irregularities. At the equator, the larger irregularities are probably produced by convective electric fields. At high latitudes, electric fields may also be involved, but other factors such as precipitating particles may contribute to, or be primarily responsible for, the production of large irregularities. Examples of other types of spectra associated with wavelike irregularities and with 'ground glass' (high-frequency noise) irregularities are also shown.
255 citations
TL;DR: The anomalous absence of excess 26Mg in meteorites is not surprising because the condensation of chondritic material from the solar nebula now seems4 to predate its later metamorphism by some 80 Myr, and the magmatic activity that produced the basaltic achondrites is younger still as discussed by the authors.
Abstract: VARIATIONS in the isotopic abundance of magnesium (78.6% 24Mg, 10.1% 25Mg, 11.3% 26Mg) have been sought1,2 in meteorites because of the possible addition of radiogenic 26Mg by the decay of 26Al. This short-lived nuclide (half-life 7.4×105 yr) is formed by proton bombardment of light elements3 and is of particular interest in theories of nucleosynthesis and heat generation during the early history of the Solar System. Analysed material must have a high Al/Mg ratio to avoid the dilution of any radiogenic 26Mg by common Mg. Consequently, previous workers have chosen mainly feldspars from basaltic achondrites and metamorphosed chondrites. The apparent absence of excess 26Mg in such meteorites is, however, not suprising, because the condensation of chondritic material from the solar nebula now seems4 to predate its later metamorphism by some 80 Myr, and the magmatic activity that produced the basaltic achondrites is younger still. Thus, the feldspars that formed as a result of these processes would incorporate aluminium that was separated from a nucleo-synthetic event by at least 80 Myr and because of its short halflife in-sufficient 26Al would remain to generate a detectable 28Mg anomaly.
142 citations
TL;DR: Strains of D. melanogaster derived from a vineyard population were more resistant to alcohol in the environment than strains from a population derived from an area removed from the vineyard.
Abstract: Strains of D. melanogaster derived from a vineyard population were more resistant to alcohol in the environment than strains from a population derived from an area removed from the vineyard. Within the vineyard population those strains most closely associated with alcohol in the environment in the cellar were more resistant than those collected outside the cellar. There was evidence of gene flow between the inside and outside cellar components of this population, but microdifferentiation had occurred within the cellar in spite of this. The adaptation appears to be independent of the ADH system and involves both additive and dominance genetic effects. D. simulans , a species not found in the cellar and susceptible to the presence of alcohol, showed no differentiation between vineyard and removed populations.
132 citations
01 Jan 1974
TL;DR: The distribution patterns of terrestrial animals and plants in Tasmania and the Bass Strait area are of great interest, for disjunctions of range can be dated and may help to reveal something of the environmental conditions prevailing at the time of isolation.
Abstract: The distribution patterns of terrestrial animals and plants in Tasmania and the Bass Strait area are of great interest, for disjunctions of range can be dated and may help to reveal something of the environmental conditions prevailing at the time of isolation. Parsons(1969, 1970) has shown there are disjunctions of plant species that can be correlated with sea level (and climatic) changes in the last Pleistocene glacial period (the Late Wisconsin) in south-eastern South Australia, in the Eyre and Yorke Peninsulas and on Kangaroo Island, and in south-western Western Australia. Thus the value of studies on Tasmanian and Bass Strait island animals and plants is increased if they also occur in these areas. Of the terrestrial vertebrates, only the reptiles can throw much light on historical biogeography, for almost every southern Australian island has a reasonably large reptile fauna, and there are disjunctions between the southeastern and south-western temperate areas. On the other hand, only the largest islands have amphibians, the mammals are poorly represented and appear to have suffered many extinctions (Spencer & Kershaw, 1910), and the birds are highly vagile, the present island avifaunas probably resulting from many invasions and colonizations since the end of the Late Wisconsin glacial.
113 citations
77 citations
75 citations
TL;DR: In this paper, the authors used the maximum likelihood and minimum variance unbiased estimator for the variance of the estimator of the parameter and the mean of the offspring distribution in a branching process.
Abstract: SUMMARY If the offspring distribution in a branching process is a power series distribution, then, conditional on extinction, the total number of descendants for the process also has a power series distribution. For this case the estimation of the parameter and of the mean of the offspring distribution is considered, using the method of maximum likelihood and minimum variance unbiasedness. The minimum variance unbiased estimator for the variance of the estimator of the parameter is also given. The results are applied to smallpox datafor Europe.
58 citations
TL;DR: In contrast to the results of other workers, isozymes A4, and B4, were shown to be immunochemically related, which is attributed to the higher degree of sensitivity in recognizing enzyme-antibody interactions using gel zymogram/immunochemical technique.
Abstract: Lactate dehydrogenase A4, from possum, chicken, and sardine muscle extracts and lactate dehydrogenase B4, from chicken heart and sardine muscle extracts have been purified. Specific activity determinations confirmed previous studies showing the A4, isoenzyme to be approximately twice as efficient as the B4, isozyme and fish lactate dehydrogenase A4, to be considerably more active than the corresponding enzyme in warm-blooded animals. Spectrophotometric analyses demonstrated striking similarities in ɛ2801 mg/ml values, which reflected a uniform tryptophan content (5 residues lactate dehydrogenase subunit) in the enzymes analysed.
Sheep antisera were prepared against each isoenzyme and used in immunochemical titration experiments to measure the extent of inhibition, precipitation and interaction of the lactate dehydrogenase isozymes by the antisera. Lactate dehydrogenase antibodies differed in their immunochemical specificities according to the nature and source of the antigen. For example, the relative affinities of antiserum to possum A4, isozyme for the enzymes was in the order, possum A4 >, chicken A4 > sardine A4, ≫, sardine B4 >, chicken B4, which compared with the affinities for antichicken B4, chicken B4 >, sardine B4≫ sardine, chicken and possum A4. In contrast to the results of other workers, isozymes A4, and B4, were shown to be immunochemically related. This observation is attributed to the higher degree of sensitivity in recognizing enzyme-antibody interactions using gel zymogram/immunochemical technique.
The antisera were also used in investigating the immunochemical properties of isozymes A′4, A′4, B4, B′4, and E4, from trout, and isozymes A4, B4 and C4 from pigeon, kangaroo and rat-tissue extracts. These vertebrate lactate dehydrogenase isozymes shared common antigenic determinants which reflected differing degrees of sequence homology and a common evolutionary origin.
57 citations
TL;DR: Field studies inside and outside the cellars of the “Chateau Tahbilk” vineyard have substantiated the distribution data of original collections, and the excess of females in the cellar and close to the fermentation area during vintage is due to the increased mortality of males in these areas.
Abstract: Field studies inside and outside the cellars of the "Chateau Tahbilk" vineyard have substantiated the distribution data of original collections D melanogaster is found inside and outside the cellars while D simulans is only collected outside The presence of alcohol fumes in the outside environment during vintage alters the distribution of the species, relative to non-vintage periods, with D melanogaster being closer to the source Mark-release-recapture experiments suggest that movement by the species towards and away from an alcohol associated resource could explain this result That is, the behavioural patterns of the species are differentially affected by the presence of alcohol in the environmentThe distribution of the sexes of D melanogaster may depend on their relative physiological tolerance to the presence of alcohol in the environment The excess of females in the cellar and close to the fermentation area during vintage is due to the increased mortality of males in these areas The reason for the distribution of the sexes of D simulans during vintage, when an excess of females is found farthest from the fermentation area, remains speculative, but may involve behavioural mechanisms
54 citations
TL;DR: During growth of Aspergillus nidulans in medium containing ammonium the specific activities of most enzymes involved in catabolism of nitrogen sources are low (ammonium repression), and the gdhA10 lesion, which results in loss of nicotinamide adenine dinucleotide phosphate-linked glutamate dehydrogenase activity, has been shown to lead to partial relief of ammonium repression of three amidase enzymes as well as histidase.
Abstract: During growth of Aspergillus nidulans in medium containing ammonium the specific activities of most enzymes involved in catabolism of nitrogen sources are low (ammonium repression). The gdhA10 lesion, which results in loss of nicotinamide adenine dinucleotide phosphate-linked glutamate dehydrogenase activity, has been shown to lead to partial relief of ammonium repression of three amidase enzymes as well as histidase. The areA102 lesion led to altered levels of these enzymes but did not greatly affect ammonium repression. The double mutant areA102,gdhA10 was almost completely insensitive to ammonium repression of two of the amidase enzymes and histidase. This suggests that an interaction between the areA and gdhA genes in determining responses to ammonium occurs. Growth of mycelium in medium containing l-glutamate has been found to result in lowered levels of all four enzymes, and this occurs in strains insensitive to ammonium repression. Very strong repression in all strains occurred during growth in medium containing l-glutamine. Relief of these repressive effects of glutamate and glutamine was blocked by cycloheximide. Glutamate and glutamine had similar effects on the production of extracellular protease activity, and growth on glutamine led to low levels of urate oxidase. In contrast to the above enzymes, nitrate reductase was insensitive to the effects of glutamine and glutamate, even though this enzyme is very sensitive to ammonium repression. Although other possibilities exist, it is suggested that there may be mechanisms of general control of nitrogen-catabolic enzymes other than ammonium repression.
TL;DR: Observations suggest that wolf spiders (Lycosidae) may exhibit behavioural thermoregulation, but it has not been demonstrated.
Abstract: LABORATORY studies have shown that wolf spiders (Lycosidae) may prefer temperatures above the ambient air temperature of their normal environment1,2. They are commonly active on clear days in winter and may repeatedly move in and out of the sun. In addition, they carry their egg sacs on their spinerettes and apparently incubate them in the sun3,4. While the observations suggest that these spiders may exhibit behavioural thermoregulation, it has not been demonstrated.
TL;DR: The chapter explores the numerous developments made in the field of oxazole chemistry from the beginning of 1955 to the end of 1972 and focuses on methods of synthesis and reactions of the mononuclear oxazoles.
Abstract: Publisher Summary This chapter discusses advances in oxazole chemistry. A significant interest in the chemistry of oxazole was revived in an effort to synthesize penicillin, when this fascinating antibiotic molecule was thought to contain an oxazole ring. In this way, aspects of oxazole chemistry are studied which had received little or no attention before. The chapter explores the numerous developments made in the field of oxazole chemistry from the beginning of 1955 to the end of 1972. The emphasis has been placed on methods of synthesis and reactions of the mononuclear oxazoles; therefore, only a few references are given to condensed oxazoles (such as benzoxazoles and naphthoxazoles). The formation of oxazoles generally predominates at around 130oC when slightly more than a molar quantity of formamide is used. The oxazole synthesis is about equally successful when α-halo ketones are boiled with a mixture of ammonium formate and formic acid (large excess) in place of formamide and concentrated sulfuric acid.
TL;DR: In this article, double labeling experiments employing 42K and 36Cl (using 10 mM KCl and 0.1 mM CaCl2 solutions) have shown that guard cells in floating epidermal strips of Vicia faba accumulate approximately 3 K ions for every Cl ion during stomatal opening.
TL;DR: The structure and cytochemistry of the filter chamber suggests that water flows from filter chamber proper to midgut and Malpighian tubules by passive osmosis, facilitated by ion binding in thefilter chamber proper and by hydrostatic pressure engendered by contraction of the muscular coat.
Abstract: The filter chamber is a complex junction of anterior and posterior extremities of the midgut and Malpighian tubules. The sac-like anterior extremity, or filter chamber proper, comprises two cell types. These are large cuboidal cells which secrete a mucoprotein, and extremely thin cells which have regular tubular invaginations of the basal plasma membrane. The posterior extremity of the midgut and the internal Malpighian tubules coil round the filter chamber proper. They consist of thin epithelial cells identical in ultrastructure. The basal plasma membrane in these cells is formed into leaflets. A thin cellular sheath and thick muscle layers surround the filter chamber. The filter chamber proper is lined by the mucoprotein secretion of the cuboidal cells. This secretion appears to bind potassium ions. ATPase and alkaline phosphatase cannot be detected in the filter chamber epithelia. The structure and cytochemistry of the filter chamber suggests that water flows from filter chamber proper to midgut and Malpighian tubules by passive osmosis. This may be facilitated by ion binding in the filter chamber proper and by hydrostatic pressure engendered by contraction of the muscular coat. The Malpighian tubules appear to be structurally and chemically adapted for ion secretion by active transport and possibly for reabsorption in the Malpighian duct segment.
TL;DR: From a survey of published data on the genus Drosophila, it is clear that male mating speed or male virility is probably the most important component of fitness.
Abstract: From a survey of published data on the genusDrosophila, it is clear that male mating speed or male virility is probably the most important component of fitness. Rapid matings tend to be controlled by the male genotype, while the genotype of the female may assume importance for slower matings. Where data exist, male mating speed is subject to directional selection in the direction of rapid speed, as would be expected for an important component of fitness.
TL;DR: The projective plane E together with the polarity π can be reconstructed from the unitary design U in such a way that any automorphism of U extends to a collineation of U which commutes with π.
TL;DR: The purpose of this paper is to show that the response changes observed in adaptation can be conceptualized as resulting from at least three distinct components—behavioral compensation, sensory adaptation, and visual shift.
Abstract: Changes in visually guided responses, including spatial judgments of object or limb position, which result from optical transformation of visual input are usually referred to as adaptation. The purpose of this paper is to show that the response changes observed in adaptation can be conceptualized as resulting from at least three distinct components—behavioral compensation, sensory adaptation, and visual shift. Data from a series of experiments show the nature of the interaction of behavioral compensation and sensory adaptation. Implications of this latter finding for intermanual transfer are discussed.
TL;DR: In this paper, a critical angle is derived such that particles whose trajectories make an angle less than it with the magnetopause enter the magnetosphere freely, so transferring their forward momentum to it.
TL;DR: Three intermediate forms of liver GOX activity are exhibited in inbred strains of the mouse Mus musculus, in addition to the parental enzymes, which is consistent with a tetrameric subunit structure.
Abstract: We have examined a polymorphism for liver GOX in inbred strains of the mouse Mus musculus. Genetic studies demonstrated that the two phenotypes for this enzyme present in BALB/C and NZC parental strains segregated as though they were controlled by codominant alleles at a single autosomal locus (GOX) which mapped closely to the agouti locus in linkage group V. Kidney HAOX activity is invariant in these inbred strains and is encoded by a separate genetic locus designated HAOX. BALB/C x NZC F1 hybrid mice exhibited three intermediate forms of liver GOX activity, in addition to the parental enzymes, which is consistent with a tetrameric subunit structure.
TL;DR: Evidence is presented which indicates that at least part of the ultraviolet protection conferred on wild-type cells by R-Utrecht can be attributed to a plasmid-coded DNA polymerase which participates in repair of single strand gaps.
Abstract: CERTAIN plasmids, including the colicin factor ColIb and the drug resistance transfer factor R-Utrecht, reduce the susceptibility of wild-type cells of Salmonella typhimurium to the lethal effects of ultraviolet irradiation while at the same time increasing their susceptibility to the mutagenic effects1,2. These alterations in ultraviolet response may result from plasmid-borne genes whose products participate in repair of single-strand gaps in DNA (ref. 2). Here I present evidence which indicates that at least part of the ultraviolet protection conferred on wild-type cells by R-Utrecht can be attributed to a plasmid-coded DNA polymerase which participates in repair of single strand gaps.
TL;DR: Evidence is presented which indicates similarities between melanin deposition in fungi and lignification in the cells of higher plants, and in P. triseta the septum separating the upper two median cells, together with the lateral conidial walls, are impregnated with melanizing material.
Abstract: Sections of developing and mature conidia of Pestalotiopsis funerea Desm. and P. triseta (F. & J. Moreau) Steyaert were examined ultrastructurally. Conidia are sheathed in single-layered walls in which the peripheral zone becomes electron dense. In P. triseta the septum separating the upper two median cells, together with the lateral conidial walls, are impregnated with melanizing material. Evidence is presented which indicates similarities between melanin deposition in fungi and lignification in the cells of higher plants.
TL;DR: The surface wax of leaves of Phormium tenax L. consists of vertical, plate-like crystals that increase in size and number and undergo a change in form during development.
Abstract: As seen in the scanning electron microscope the surface wax of leaves of Phormium tenax L. consists of vertical, plate-like crystals. These increase in size and number and undergo a change in form during development. The abaxial surface has a dense covering of wax crystals, but none are present on the ridges over vascular tissues. Numerous papillae are found between these ridges in later stages of development. On the adaxial surface both wax crystals and papillae are present only around infrequent stomata.When viewed in section normal to the leaf surface the cuticle is first apparent as a thin, lamellate layer. Another layer containing a reticulum of electrondense material increases in thickness beneath the lamellae during development. This layer eventually becomes the most extensive component of the cuticle. Both the adaxial and abaxial cuticles show a similar pattern of development.
TL;DR: It is suggested that correlation of changes in the volume of extracellular space with changes in ion and water transport must be regarded with caution.
Abstract: Ephydrella larvae strictly regulate their blood osmotic pressure and Na + content over a wide range of environmental salinities (7 mM to 3000 mM NaCl). They can survive in distilled water and 6000 mM NaCl for several days. In the hindgut the ileum is concerned with the regulation of urine composition whilst the rectum has a purely mechanical function. In the ileum there are large cells which have long basal channels and short apical microvilli, and small cells which have long apical leaflets and short basal channels. It is suggested that the large cells reabsorb water and that the small cells either reabsorb or secrete ions. The configurations of the channels, and the spacing of leaflets and microvilli change with alterations in environmental salinity. Fixation experiments using fixatives of different osmotic pressures show that the configuration of extracellular space in the cells has a marked dependence on both the osmotic pressure of the fixative and upon the environmental salinity. It is suggested that the osmotic response of the cells to fixatives indicates that the osmotic pressure of the cells increases with increasing environmental salinity. It is suggested, in general, that correlation of changes in the volume of extracellular space with changes in ion and water transport must be regarded with caution.
TL;DR: In this paper, the pseudomorphic replacement is generally equal area; the replacement is usually by a single mineral or, where a number occur, one volumetrically greatly predominates; and successive reaction coronas exist around a single reactant grain.
Abstract: Existing staurolite breakdown reactions are briefly discussed and examples of each of the main types suggested from textural evidence from different well studied areas are analyzed. From the staurolite textural data, it is shown that: the pseudomorphic replacement is generally equal area; the replacement is usually by a single mineral or, where a number occur, one volumetrically greatly predominates; and successive reaction coronas exist around a single reactant grain. The analogy between the textural coronas and “monomineralic zones” at the contact of dissimilar rock types is drawn with the subsequent inference that reaction coronas in some, if not most, cases are out of equilibrium with the rest of the assemblage as well as the reactant mineral. In staurolite reaction textures, different grains in a single thin section normally have: different amounts (ratios) of product minerals, different product minerals, some grains which have reacted while others have not and different grains which have reacted to different degrees.
TL;DR: In this article, the total electron content data of 20 geostationary radio beacons were collected in order to study the ionospheric storm of 17 December 1971, and a remarkable increase in the total ion content occurred at midlatitude stations throughout the northern hemisphere, and stations at auroral and equatorial latitudes also showed sharp increases which were both LT and latitude dependent whereas both sites in the southern hemisphere showed substantial depletions.
TL;DR: In this paper, a source for the production of high intensity resonance radiation from inert gases has been developed in a form suitable for use with ultrahigh vacuum, and it has been used for the development of a high intensity radar.
TL;DR: It was concluded that the reaction catalysed by spinach leaf ATP sulphurylase was ordered and the expected exchange reaction between sulphate and adenosine 5'-sulphatophosphate could not be demonstrated.
Abstract: 1. Sulphate-dependent PP(i)-ATP exchange, catalysed by purified spinach leaf ATP sulphurylase, was correlated with the concentration of MgATP(2-) and MgP(2)O(7) (2-); ATP sulphurylase activity was not correlated with the concentration of free Mg(2+). 2. Sulphate-dependent PP(i)-ATP exchange was independent of PP(i) concentration, but dependent on the concentration of ATP and sulphate. The rate of sulphate-dependent PP(i)-ATP exchange was quantitatively defined by the rate equation applicable to the initial rate of a bireactant sequential mechanism under steady-state conditions. 3. Chlorate, nitrate and ADP inhibited the exchange reaction. The inhibition by chlorate and nitrate was uncompetitive with respect to ATP and competitive with respect to sulphate. The inhibition by ADP was competitive with respect to ATP and non-competitive with respect to sulphate. 4. ATP sulphurylase catalysed the synthesis of [(32)P]ATP from [(32)P]PP(i) and adenosine 5'-sulphatophosphate in the absence of sulphate; some properties of the reaction are described. Enzyme activity was dependent on the concentration of PP(i) and adenosine 5'-sulphatophosphate. 5. The synthesis of ATP from PP(i) and adenosine 5'-sulphatophosphate was inhibited by sulphate and ATP. The inhibition by sulphate was non-competitive with respect to PP(i) and adenosine 5'-sulphatophosphate; the inhibition by ATP was competitive with respect to adenosine 5'-sulphatophosphate and non-competitive with respect to PP(i). It was concluded that the reaction catalysed by spinach leaf ATP sulphurylase was ordered; expressing the order in the forward direction, MgATP(2-) was the first product to react with the enzyme and MgP(2)O(7) (2-) was the first product released. 6. The expected exchange reaction between sulphate and adenosine 5'-sulphatophosphate could not be demonstrated.
TL;DR: The kinetics of the inhibition for each enzyme were consistent with an ordered reaction mechanism, in which ATP is the first substrate to react with the enzyme and PP(i) is thefirst product released.
Abstract: 1. ATP sulphurylases were partially purified (20–40-fold) from leaf tissue of Astragalus bisulcatus, Astragalus racemosus (selenium-accumulator species) and Astragalus hamosus and Astragalus sinicus (non-accumulator species). Activity was measured by sulphate-dependent PPi–ATP exchange. The enzymes were separated from pyrophosphatase and adenosine triphosphatase activities. The properties of the Astragalus ATP sulphurylases were similar to the spinach enzyme. 2. The ATP sulphurylases from both selenium-accumulator and non-accumulator species catalysed selenate-dependent PPi–ATP exchange; selenate competed with sulphate. The ratio of V(selenate)/V(sulphate) and Km(selenate)/Km(sulphate) was approximately the same for the enzyme from each species. 3. Sulphate-dependent PPi–ATP exchange was inhibited by ADP, chlorate and nitrate. The kinetics of the inhibition for each enzyme were consistent with an ordered reaction mechanism, in which ATP is the first substrate to react with the enzyme and PPi is the first product released. 4. Synthesis of adenosine 5′-[35S]sulphatophosphate from [35S]sulphate was demonstrated by coupling the Astragalus ATP sulphurylases with Mg2+-dependent pyrophosphatase; the reaction was inhibited by selenate. An analogous reaction using [75Se]selenate as substrate could not be demonstrated.
TL;DR: In this article, a method was described for the measurement of relative subshell photoionization cross sections (SPCS) in the noble gases by the technique of ultraviolet photoelectron spectroscopy.
Abstract: A method is described for the measurement of relative subshell photoionization cross sections (SPCS) in the noble gases by the technique of ultraviolet photoelectron spectroscopy. Values are reported for the photoionization cross sections of the neon $2p$, krypton $4p$, xenon $5p$, and xenon $5s$ levels relative to that of the argon $3p$ level. The photon energies used for these measurements were 21.22, 40.81, and 48.37 eV. Approximate absolute subshell photoionization cross sections deduced from these relative cross sections are compared to other absolute SPCS obtained from total photoabsorption measurements and also from theory. Results of some relative photoionization cross-section measurements for the outer $p$ bands associated with the halide ions in solid alkali halides and the outer $d$ bands of metallic gold and silver are also presented. Close similarities in variation with photon energy and atomic number are found between the relative photoionization cross sections of the outer $p$ bands of the alkali halides and the outer $p$ levels of the noble gases, but the photoionization cross sections of the $d$ bands of both gold and silver exhibit quite different properties from those found for the outer $p$ bands and levels of both alkali halides and noble gases. A general conclusion is drawn concerning cross sections for photoionization from electron energy bands in solids.