Mind Architecture and Brain Architecture

The use of the computer metaphor has led to the proposal of mind architecture (Pylyshyn 1984; Newell 1990) as a model of the organization of the mind. The dualist computational model, however, has, since the earliest days of psychological functionalism, required that the concepts mind architecture and brain architecture be remote from each other. The development of both connectionism and neurocomputational science, has sought to dispense with this dualism and provide general models of consciousness – a uniform cognitive architecture –, which is in general reductionist, but which retains the computer metaphor. This paper examines, in the first place, the concepts of mind architecture and brain architecture, in order to evaluate the syntheses which have recently been offered. It then moves on to show how modifications which have been made to classical functionalist mind architectures, with the aim of making them compatible with brain architectures, are unable to resolve some of the most serious problems of functionalism. Some suggestions are given as to why it is not possible to relate mind structures and brain structures by using neurocomputational approaches, and finally the question is raised of the validity of reductionism in a theory which sets out to unite mind and brain architectures.     

Nicotiana chloroplast genome

Summary Using the existing restriction map and probes from wheat and pea ct-DNA, seven protein genes have been localized in the chloroplast genome of N. tabacum. On the clock-like map, the location of each gene is indicated by its time zone: the 15.2 kD polypeptide of the cytochrome b/f complex at 315, cytochrome f at 430, LS of RuBPCase at 450, both and subunits of ATP synthase at or near 500, proton-translocating subunit of ATP synthase at 820, subunit of ATP synthase at 840 and the 32 kD protein at 930. The genome organization of Nicotiana chloroplast DNA is similar to spinach.     

Bacterial regeneration of ammonium and phosphate as affected by the carbon:nitrogen:phosphorus ratio of organic substrates

The effect of carbonnitrogenphosphorus (CNP) ratio of organic substrates on the regeneration of ammonium and phosphate was investigated by growing natural assemblages of freshwater bacteria in mineral media supplemented with the simple organic C, N, and P sources (glucose, asparagine, and sodium glycerophosphate, respectively) to give 25 different substrate CNP ratios. Both ammonium and phosphate were regenerated when CN and NP atomic ratios of organic substrates were 101 and 161, respectively. Only ammonium was regenerated when CN and NP ratios were 101 and 10–201, respectively. On the other hand, neither ammonium nor phosphate was regenerated when CN and NP ratios were 151 and 51, respectively. In no case was phosphate alone regenerated. As bacteria were able to alter widely the CNP ratio of their biomass, the growth yield of bacteria appeared primarily dependent on the substrate carbon concentration, irrespective of a wide variation in the substrate CNP ratio.     

Localization of the gene for human heart fatty acid binding protein to chromosome 1p32-1p33

Among 639 spontaneous abortions between the 8th and 14th week of gestation 342 (53.5%) revealed an abnormal karyotype. While the rate of trisomies distinctly increased with advancing maternal age, a decrease in the rate of 45,X conceptuses and polyploidies was observed among abortions from older women. The overall relation of XXXXXXYY among the tetraploidies was 1411 and that of XXXXXYXYY among the triploidies was 26 361. However, when the latter was related to maternal age, a reversal of the XXXXXY ratio of 12 in the younger to 21 in the older age groups became evident. Furthermore a decrease in the rate of paternally derived partial hydatidiform moles was found among the triploid abortion specimens from older women. From these observations we conclude that digyny plays a major role in the origin of triploidy in the increased maternal age groups, while diandry related to immaturity of oocytes and impairment of oocyte cortical function is more frequent in triploid abortions from younger women.     

On the structure of carminic acid and carmine

Summary The chemical mechanism and histochemical significance of carmine stains are not yet understood. To determine possible effects of dye configuration on staining patterns we built models of dye molecules with the Stuart-Briegleb-type of atomic models. However, steric hindrance prevented construction of carmine according to the formula suggested by Harms. A review of recent chemical literature showed that the widely accepted formula of carminic acid is incorrect; the carboxyl group is not in the 5 but in the 7-position, and the side-chain is not a methylpentose but a hexose. Models based on the revised structural formula could be combined to 211 carminic acid-Al-Ca complexes. But formation of the central Al-O-Ca-O-Al bridge of the conventional 421 carminic acid-Al-Ca formula of carmine was still impossible. It is suggested that carmine may be a 211 compound analogous to the 211 alizarin-Al-Ca complex established by Kiel and Heertjes. Investigations of carmine were rendered difficult by wide variations in the staining properties of dye samples and the lack of data concerning the composition of various batches of carmine.     

Sex determination in Sarotherodon (tilapia)

Summary The simplest possible model of the sex determination process adding autosomal influence to a minimal number of sex chromosomes was developed to explain matings of Tilapia (Sarotherodon) species. Eighteen different genotypes, each having two autosomes (AA, Aa, or aa) and two sex chromosomes (WX, WY, WW, XY, XX or YY) involved in sex determination, are predicted by the theory. Their sex (10 males and 8 females) were determined using a series of directed graphs, showing the relative strength of the chromosome pairs, developed on the basis of Chen's sex ratio results (Chen 1969). This theoretical model predicts eight different sex ratios (01, 13, 35, 11, 97, 53, 31, 10 ); three of them are not predicted by the WXYZ theory. The greatest part of these sex ratios have been obtained experimentally in extensive series of crosses between related species of Tilapia and their hybrids, carried out by several authors. The theory succeeds in explaining all of Chen's results, including those ratios 53 and 01 seen in certain crosses but not predicted by the WXYZ theory. The importance of the autosomes is seen in comparisons of the genotype pairs (AaWY, aaWY), (AaXY, aaXY) and (AAWW, AaWW) in which the first genotype in each case is male while the second is female as proven by the sex ratio results. The members of the pair differ only in the substitution of one autosome for the other. To test the theory, experiments consisting of hormonal sex reversion and a series of crosses are proposed. Finally, theoretical and practical implications of the theory are discussed.     

Cellular fatty acid composition of six fastidious,gramnegative, xylem-limited bacteria from plants

Composition of cellular fatty acids was determined for strains of fastidious, Gramnegative, xylem-limited bacteria causing or associated with Pierce's disease of grapevine, phony disease of peach, plum leaf scorch, stunt of ragweed, elm leaf scorch, and periwinkle wilt. The most abundant fatty acids were straight-chain 150, 160, 170, and 180, unsaturated 161, 181, and unsaturated 17-and 19=carbon homologs. Minor fatty acids included straightchain 120, 140, 190, and 200; an unsaturated 15-carbon homolog; hydroxy-substituted 2-OH 120, 3-OH 120, and 3-OH 140; and branched chain iso-140 and iso-200. Cyclopropane acids were not detected. Physiological age had no effect on fatty acid composition. Class analysis of data indicated relative uniformity within the group. Saturated even-carbon chains comprised 31%–42%, unsaturated acids 41%–52%, saturated odd-carbon chains 10%–18%, hydroxysubstituted chains 2%–7%, and branched-chains 1%–4% of total fatty acids. The ratio of saturated-unsaturated acids ranged from 0.8 to 1.2.     

Thiol-dependent passive K:Cl transport in sheep red blood cells: X. A hydroxylamine-oxidation induced K:Cl flux blocked by diethylpyrocarbonate

Summary Hydroxylamine, a potent oxidizing agent used to reverse carbethoxylation of histidine by diethylpyrocarbonate, activated Cl-dependent K flux (KCl cotransport) of low K sheep red blood cells almost sixfold. When KCl cotransport was already stimulated by N-ethylmaleimide, hydroxylamine caused an additional twofold activation suggesting modification of sites different from those thiol alkylated. This conclusion was supported by the finding that hydroxylamine additively augmented also the diamide-induced KCl flux (Lauf, P.K. 1988.J. Membrane Biol. 101:179–188) with dithiothreitol fully reversing the diamide but not the hydroxylamine effect. Stimulation of KCl cotransport by hydroxylamine was completely inhibited by treatment with diethylpyrocarbonate also known to prevent KCl cotransport stimulation by N-ethylmaleimide, both effects being independent of the order of addition. Hence, although the effect of carbethoxy modification on KCl flux cannot be reversed by hydroxylamine and thus excludes histidine as the target for diethylpyrocarbonate, our finding reveals an important chemical determinant of KCl cotransport stimulation by both hydroxylamine oxidation and thiol group alkylation.     

Style morph frequencies in Minnesota populations of Lythrum (Lythraceae)

Style morph frequencies (shortmidlong) were determined for a total of n = 11 918 plants in 16 Minnesota populations of Lythrum salicaria L. Nine populations were in the establishment phase, with population sizes ranging from n = 56 to n = 2 192. Most of these populations exceeded previously reported population sizes in the native European habitat. A nonparametric statistical test, the chi-square (²), can be used to determine if populations are at isoplethic equilibrium (111, shortmidlong); a ² value >5.99 is significant at the 5% level. Only one established population (White Bear Lake, n = 1991, ² = 3.0) fitted the null hypothesis for isoplethy, although all established populations contained all three style morphs. Pooled values for these populations indicated an excess of mids and longs, with shorts being deficient. Colonizing populations had a higher percentage of mids (54%) when compared to established populations (33.7%). Short styles were almost nonexistent (8%) in colonizing populations. Five out of the seven populations lacked at least one style morph. A review of the literature reporting style morph frequencies in tristylous L. salicaria revealed that no statistical analysis for isoplethy has been performed. Darwin originally assumed that all populations would be isoplethic, possessing equal numbers of all three style morphs, but concluded, without statistical analysis, that, instead, populations were anisoplethic. Since tests for statistical deviations from the expected frequencies (111) have not been used, ² analysis was performed. Several of these populations were at isoplethic equilibrium (Nadder su2 = 1.7, Blelham ² = 1.69, Potsdam ² = 1.5, Vestfold ² = 0.4, Buskerud ² = 5.62, Kilchberg ² = 0.35, Lausanne ² = 3.32, Canberra ² = 5.29, Massachusetts ² = 3.13), suggesting that the general conclusion of anisoplethy in tristylous L. salicaria is inappropriate.This is Scientific Journal Series Paper Number 19 128 of the Minnesota Agricultural Experiment Station     

Structure of the majorO-glycosidic oligosaccharide of monkey erythrocyte glycophorin

Sialic acids and the majorO-glycosidic oligosaccharide of glycophorin MK from monkey (Japanese monkey,Macaca fuscata) erythrocyte membranes were characterized.N-Glycolylneuraminic acid (neu5Gc) was found as the major sialic acid, which was confirmed by gas-liquid chromatography-mass spectrometry as the trimethylsilyl methyl ester. ThreeO-glycosidic oligosaccharide units were obtained from a tryptic glycopeptide that contained all of the carbohydrate units in glycophorin MK by mild alkaline borohydride/borotritide treatment. Carbohydrate analyses of the oligosaccharides revealed that they were composed of Neu5Gc, galactose andN-acetylgalactosaminitol in the molar ratios of 111 (trisaccharide), 211 (tetrasaccharide) and 111 (pentasaccharide). The content of oligosaccharide units was estimated to be 1125 for penta-, tetra- and trisaccharide, respectively, based on the yields, the molecular weight, and the number of oligosaccharide attachment sites in the amino-acid sequence. The tetrasaccharide was the major oligosaccharide and its structure was proposed to be Neu5Gc2-3Gal1-3[Neu5Gc2-6]GalNAcol.     

Circadian effects of hydrocortisone on the blood of the newt,Notophthalmus viridescens

Summary Differential counts of the leucocytes of newts,Notophthalmus viridescens, were made at four times of day (200, 900, 1400 and 2100), 72 hours after the injection of hydrocortisone acetate (experimentais) or distilled water (controls). At all times, increases in neutrophils and decreases in lymphocytes were observed in experimentais as compared to the controls (Table 1). The increases in neutrophils in the experimental newts were most pronounced at 1400, and the decreases in the lymphocytes were greatest at 2100. The least degrees of neutrophilia and lymphopenia occurred at 900. Consequently, circadian variations in response to the hydrocortisone are indicated. The possible mechanism of mediation of the variations is discussed.Supported in part by National Science Foundation grant, GY-7661, to Sweet Briar College.     

Genetics of fertility restoration in hybrid rice

Summary The cross combination involving 14 male-sterile lines in rice, when crossed with different maintainers, showed fertility restoration in certain combinations. When F₂ segregating populations were classified based on spikelet fertility, fertility restoration was shown to be governed by 31, 9331, and 1231, due to allelic differences. This indicated that the cytosterility of the same group showed monogenic fertility restoration, whereas crossing plants belonging to different cystosterile groups showed a digenic pattern of segregation.     

The effect of spectral light deprivation on the spectral sensitivity of the honey bee

Summary The spectral sensitivity of spontaneous phototactic behavior was tested in short wavelength deprived bees and in control bees kept outdoors. Tests were performed with a y-maze with one branch illuminated, the other dark. The relative sensitivities for the control group were: green to blue to UV = 10.272.14. Short wavelength deprived bees show a distinct decrease in their sensitivity to short wavelengths. The relation green to blue to UV here was 10.220.27. Forager bees from outdooors, short wavelength deprived for 10 days, showed a relation of green to blue to UV of 10.261.04. Electrophysiological investigation of the compound eye using electroretinogram recordings showed no difference between deprived and control animals.     

Aflatoxin — induced alteration in the levels of membrane chemicals of subcellular organelles isolated from excised,incubated Glycine max,cv. ‘Essex’ roots

Isolates of aflatoxin-producing strains of Aspergillus grow on autoclaved and field-grown (lesser extent) Glycine max beans. Both mixed and aflatoxin B₁ inhibit G. max, cv. Essex bean germination and elongation of either attached or excised cultured roots. Because B₁ impairs the latter roots' ability to intracellularize [¹⁴C]-leucine, it may alter plasmalemma structure and/or function. To determine whether incubation of excised roots for 18 hours in toxin-containing medium could affect cellular membrane chemical content, organelles were isolated by differential centrifugation (1 000, 40 000, and 80 000 xg) of homogenates and characterized chemically. Statistically significant differences between treated and untreated roots in acid insoluble protein but not either sterol or lipid phosphorus levels were observed for both 40,000 and 80,000 xg pellets. Protein and sterol recoveries were 81 (treated) and 84 (untreated) % for the former and 77 (treated) and 79 (untreated) % for the latter. Lipid phosphorus recoveries were 87.3 (treated) and 136 (untreated) % with and 96 (treated) and 83 (untreated) without membrane stabilization. Protein:sterol:lipid phosphorus were 35.74.51 (1 000 xg), 18.93.61 (40000 xg), 26.34.61 (80 000 xg) and 1,010291 (80 000 xg supernatant) for untreated and 36.93.31 (1,000 xg), 23.13.81 (40 000 xg), 36.24.81 (80 000 xg) and 1,05321.71 (80 000 xg supernatant) for treated roots. Significant differences in RNA content between treated and untreated roots were found for both 1 000 and 40 000 xg pellets but not for the 80 000 xg pellet and its supernatant. Whereas a significant increase in the 1 000 xg pellet occurred upon treatment, a decrease was noted for the 40 000 xg pellet but not for the 80 000 xg pellet and its supernatant. Similar pH 6 (plasmalemma marker enzyme) and 9 (mitochondrial marker enzyme) K⁺-stimulated ATPase activities were demonstrated for 40 000 and 80 000 xg pellets. The 1 000 xg pellet contained greater than 50% of the NADH-cytochrome c-reductase activity (endoplasmic reticulum marker enzyme) recovered from fractions examined for this activity which was absent from the 40 000 xg pellet. Both the 80 000 xg pellet and its supernatant possessed equivalent reductase activities. Inosine diphosphatase activity (dictyosome marker enzyme) was not present in 1 000 xg pellets obtained from either treated or untreated roots but was in both 40 000 and 80 000 xg pellets. Based on these results, a tentative assignment of organelles to each fraction (xg force) is reported.Abbreviations used AFB₁ aflatoxin B₁ - AFB₂ aflatoxin, B₂ - AFG₁ aflatoxin G₁ - AFG₂ aflatoxin G₂ - ATPase adenosine triphosphatase - IDPase inosine diphosphatase - NADH reduced nicotinamide-adenine dinucleotide - PCA perchloric acid - TCA trichloroacetic acid - 2, 4-D 2,4-dichlorophenoxyacetic acid Aided by grant IN-127 from the American Cancer Society to WVD and funds from the Departments of Biology, West Virginia University and Virginia Commonwealth University as well as a Sigma Xi award to JMD.     

The structure of the incompatibility factors of Schizophyllum commune: Constitution of the three classes of B factors

Summary The B factors of Schizophyllum commune are of 3 classes: The high recombining class I has 7 alleles and 7 alleles; the low recombining classes are class II with 7 allels and probably 2 alleles and class III with probably 2 (or also 2) alleles and 7 allels. A fourth hypothetical class (-) was not found and either does not exist or is indistinguishable from class III by the tests employed. The and alleles differ from and by either (a) mutations affecting both mating specificity and recombination frequency, or (b) deletions involving most of the B region.The research was supported by a grant from the Atomic Energy Commission of the U.S. No. (30-1)-3875 and was performed at the Biological Laboratories, Harvard University, Cambridge, Mass., U.S.A.     

N-3 and n-6 fatty acid metabolism in undifferentiated and differentiated human intestine cell line (Caco-2)

Metabolism of n-6 and n-3 fatty acids in the undifferentiated and differentiated human adenocarcinoma colon cell line (Caco-2) was studied. In cells incubated with either 182n-6 or 183n-3, no significant amounts of long chain n-6 and n-3 metabolites were found. Incubation with either 183n-6 or 184n-3 raised significantly the levels of 203n-6 and 204n-3, respectively. In the undifferentiated cells, significant proportions of 203n-6 and 204n-3 were further 5-desaturated to form 204n-6 and 205n-3, respectively. Incubation with either 204n-6 or 205n-3 raised the levels of their direct elongation products, 224n-6 and 225n-3, respectively. Incubation with 224n-6 or 225n-3 increased the levels of 204n-6 and 205n-6. These results suggest that 6-desaturation in the Caco-2 cells is less active in comparision with elongation, 5-desaturation and retro-conversion. These enzymes were modulated by the state of differentiation, and appeared to be non-specific to n-3 and n-6 fatty acids. When cells were incubated with 183n-6 and 184n-3 concomitantly, the levels of incorporation of total n-6 fatty acids into cellular lipids were greater than those of the n-3 fatty acids, whereas the ratios of 20+22 carbon metabolites to 18-carbon precursor favored n-3 over n-6 fatty acids. These results suggest that n-3 and n-6 fatty acids were not metabolized identically in Caco-2 cells.     

Effect of thermal stress on the neurosecretory cells of the freshwater prawn,macrobrachium kistnensis (Tiwari)

The brain and thoracic ganglion neurosecretory cells of the freshwater prawn, M. kistnensis displayed characteristic changes following 24 hr exposure to warm (31.0° ± 0.5°C) and cold (13.0° ±0.5°C) stress. A and B cells from the brain showed significant elevation in their nuclear diameters after warm and cold stress. Warm stress depressed whereas cold stress enhanced the neurosecretory material intensity of A cells. However, the intensity of B cells neurosecretory material remained unaltered following both treatments. On the contrary nuclear diameters of both A and B neurosecretory cell significantly decreased and an increment in neurosecretory material intensity was revealed in the thoracic ganglion of both warm and cold stressed prawns.     

Modification of the properties of a translocation in the German cockroach by selection

Summary A stock of Blattella germanica bearing the interchange T(3; 12)/3;12 was subjected to close inbreeding with selection for random disjunction at metaphase I. After 3–4 generations of selection, interchange quadrivalent chiasma frequency decreased, variability in free bivalent chiasma frequency increased sharply, and individuals with either random or directed disjunction were present in the stock. Random disjunction was modified from a ratio of 2112 (adj.-1; alt.-1; adj.-2; alt.-2) to a ratio of 1111. After 7–8 generations of selection, chiasma frequency appeared to stabilize at lower than normal levels and variability decreased for both quadrivalents and free bivalents. Directed disjunction was modified from a ratio of 2114 to 1112, and no individuals with the original high level of directed disjunction were detected. Chains-of-four tended to orient randomly, especially in individuals where the ring quadrivalents showed directed disjunction. Relaxation of inbreeding, but not selection, produced an increase in chiasma frequency and variability in both free bivalents and quadrivalents, but the modified ratios for both random and directed disjunction were retained. These results are discussed with respect to inbreeding effects and genetic control of chiasma frequency and metaphase I disjunction in interchange quadrivalents.     

Distribution and composition of particulate organic matter in the Ross Sea (Antarctica)

The biochemical composition and spatial distribution of particulate organic matter (POM) were studied in the Ross Sea (Antarctica) in summer 1989 to assess the quantitative role of organic carbon fractions in the cycling of organic matter in the water column. Large differences in chemical composition were observed between surface and deep layers. The results indicated that, despite large geographical differences, POM was quite homogeneous, of phytoplankton origin and mostly detrital. Different ratios were used to investigate the changes in biochemical composition of particulate organic matter in relation to the ice-melting: CN (organic carbonorganic nitrogen ratio) and C-POMPOC (sum of carbohydrate, protein and lipid carbontotal organic carbon ratio) were used to analyse the percentage of refractory organic material. PPRTPCHO (proteincarbohydrate ratio) were used to establish POM age and RNADNA ratios as a relative measure of particulate activity; POCChl a and N-PPRTChl a ratios were used to estimate the autotrophic contribution to the suspended particulate organic matter. Despite its low caloric value (5.3 Kcal g POM^–1), an high caloric content in the photic layer (1.6 Kcal m^–3 of POM and 2.5 Kcal m^–3 of POC) was found thus indicating that a large amount of food was available to higher trophic levels.     

Effect of light-dark cycles with different LD time-ratios and different LD intensity-ratios on the activity rhythm of chaffinches

Summary Chaffinches (Fringilla coelebs L.) were kept at light-dark (LD) cycles with two different light intensity ratios (ca. 500.1 and ca. 101 lux) both with 1.83 hours of twilight at the onset and end of light time. The light time/dark time ratio (LD time-ratio) was varied in the range from 420 to 222 hours.Birds at the high LD intensity-ratio (500.1 lux) increased activity time () with increasing light time from LD 420 to 222. Time of activity onset, middle, and end of activity corresponded to onset, middle, and end of light time from LD 420 to 168, but the phase angles of middle and end of activity (related to midpoint of light time and midpoint of artificial dusk respectively) became more positive (advanced) at LD 204 and 222.Birds at the lower LD intensity-ratio (101 lux) increased activity time with increasing light time from LD 816 to 204 but activity time at LD 420 was equivalent to that at LD 816. The phase angles of activity onset and middle (related to midpoint of artificial dawn and midpoint of light time, respectively) became more positive at both long (LD 204) and short (LD 420) light times.By use of different twilight regimes (linear and logarithmic changes in intensity), it was shown that end of activity was more closely related with the rate of change and/or absolute level of light intensity than was onset of activity.During January and February, the birds responded to increased LD time-ratios by an increase of activity time and by strong positive phase angle shifts which correspond to observations of activity patterns of chaffinches exposed to outdoor conditions during the spring breeding season.The free-running circadian periods () of 6 birds measured at 15 lux at the end of the experiments following LD 204 averaged 22.17 hours.From the data on precision, i. e. the period-to-period variation in the phase angles of single birds averaged over all birds of one group and condition, as well as from the number of birds not synchronized with the LD cycles, it is concluded that extreme long and short light times per 24 h represent weaker zeitgebers compared to LD cycles with medium lengths of light time. Likewise, LD cycles with low LD intensity-ratios are weaker zeitgebers than LD cycles with high LD intensity-ratios.This study was carried out while the senior author was on sabbatical leave from the University of Alaska and held a fellowship from the Alexander von Humboldt Stiftung.