THE QUANTIC AND STATISTICAL BASES OF VISUAL EXCITATION

In the article entitled "The quantic and statistical bases of visual excitation" (J. Gen. Physiol., 1947–48, 31, 269), in footnote 1, at the bottom of page 274, read, The product k (k–1) ..., may be written See PDF for Equation. On page 284, in equation (1) add, t = mτ; m = 1,2,3.... I take this occasion to call attention to the fact that in 1944 van der Velden developed two equations, one of which described the variation of liminal energy with the flash time and the other this variation with the visual angle of the spot; both of them apply in the case of homogeneous populations of receptors (rods). These equations are very similar to mine, obtained in an entirely different manner and published nearly 4 years later. In fact, until very recently I was not aware of the equations of van der Velden, published in Physica, 1944, 11, 179, because the papers published in that journal, and particularly those which are written in Dutch, generally become known to French physiologists as abstracts which are often incomplete. Thus the priority of the theoretical basis of the empirical laws which are directly related to the two equations in question belongs entirely to van der Velden. ERNEST L. M. BAUMGARDT In Vol. 31, No. 3, January 20, 1948, page 261, in equation (1) for H ₂ read H ₁. On page 262, in equation (5) for H read H ₂. On page 265, in the third line from the bottom of the page, for 4 c.mm. read 5.24 c.mm. On the same page, in the second line from the bottom of the page, for 5 c.mm. read 6.86 c.mm.     

THEORY AND MEASUREMENT OF VISUAL MECHANISMS : XI. ON FLICKER WITH SUBDIVIDED FIELDS

In Vol. 27, No. 5, May 20, 1944, page 403, in the eighth line from the bottom of the page, the comma after "intensity" should be a semicolon. On page 413, in the second formula from the bottom of the page, for See PDF for Equation read See PDF for Equation On the same page, formula 2 should read See PDF for Equation On page 414, line 3, at the end of the line add "or" to read "of the level of I or of F." On page 422, in the first line below the figure legend, for "illuminate" read "illuminated." On page 430, line 22, for "lighteb dars" read "lighted bars."     

Corrections

Vol. 30, parts 1 and 2 page 45, line 7 for "Canyon" read "Cayman". page 46 line 27for "2G; 7.xi.l937" read "36; 2.vi.l938". page 50 line 5 for "31" read "27". delete "dredged at 3 &metres". page 50 line 32 for "26; 7.xi.l937" read "30; 2.vi.l938". page 53 line 6 for "19.x.l937" read "8.v.l938". page 10, line 35, for "niiudula" read nitidula. page 21, figure 29, for "L. 8248" read "L. 82482". page 61, line 12, for "holotype (B.M. 43100)" read "syntypes(B.M. 43106, L. 82350)". page 64, line 23, for "Coriopsis" read "Cordiopsis". p. 64, lines 34 and 3G, for "lyell" read "lyellii". page 76, line 37, "Rzymowska 1914" should follow "Taylor (1900)"in line 36. page 77, line 43, for "Xerotrhicha" read "Xerotricha". page 87, line 1, for "twelve" read "ten". page 90, lines 44 and 45, for "marginal (M)" read "lateral",and for "two lateral teeth (L₁ L₂)" read "two marginal teeth".In figure 2, for "esehalent" read "exhalent". pp. 123, 125, 127, 129, headings, for "Pseudoneptunia" read"Pseudoneptunea" p. 124, line 34, for "highgatenis" read "highgatensis". p. 125, The locality of the Sedgwick Museum specimens C. 12891of Siphonalia ferroviae should be given as Titchfield, Hants.,and not as Portsmouth Dock.     

ERRATA

page 13, legend to figure 14 : insert c, before two page 137, paragraph on Ampulla : for pulieum read pulicum page 145, line 6 from bottom : for versicolor (Gmelin) readversicolor Gmelin      

CONTRIBUTION TO THE THEORY OF PERMEABILITY OF MEMBRANES FOR ELECTROLYTES

On page 39, Vol. viii, No. 2, September 18, 1925, multiply the right-hand side of formula (2) by the factor See PDF for Equation. On page 44, immediately after formula (1) the text should be continued as follows: Let us suppose a membrane to be separated by two solutions of KCl of different concentrations K₁ and K₂ and these concentrations and the corresponding concentrations of K⁺ within the membrane, which are in equilibrium with the outside solutions, to be so high that the H⁺ ions may be neglected. When a small electric current flows across the system, practically the K⁺ ions alone are transferred and that in a reversible manner. Therefore the total P.D. is practically See PDF for Equation This P.D. is composed of two P.D.''s at the boundaries and the diffusion potential within the membrane. Suppose the immobility of the anions is not absolute but only relative as compared with the mobility of the cations, KCl would gradually penetrate into the membrane to equal concentration with the outside solution on either side and no boundary potential would be established. In this case the diffusion P.D. within the membrane is the only P.D., amounting to See PDF for Equation but, V being practically = 0, it would result that See PDF for Equation So the definitive result is the same as in the former case. Now cancel the printed text as far as page 48, line 13 from the top of the page, but retain Fig. 1. On page 50, line 19 from the top of the page, cancel the sentence beginning with the word But and ending with the words of the chain.     

Quantitation of plasmid DNA in aqueous two-phase systems by fluorescence analysis

The development of aqueous two-phase systems for plasmid purification from Escherichia coli cell lysates requires a reliable DNA quantitation method. Plasmid DNA was quantified by fluorescence using PicoGreen nucleic acid stain. Linearity was obtained up to 40 ng plasmid ml^–1. Two polyethyleneglycol (PEG)/salt systems were studied, PEG 600/K₂HPO₄ and PEG 300/K₂HPO₄. The average plasmid recovery was 41% in the bottom phase of the first system and 35% in the top phase of the second system. This method has proved to be simple and reproducible.     

HP4 - and (CH2)P3 - Anions Form Four-membered Rings with an Allyl Moiety – An ab initio/NMR study

On the energy hypersurfaces of the anions HP₄ ^- and CH₂P₃ ^- at the RMP2(fc) /6-31+G(d) level, the isomers with triphosphaallyl moiety are the lowest energy structures. For these free 1-X-2,4-(P_B)₂-3-P_A ^- anions characteristic ³¹P NMR chemical shifts, are predicted to be (for X = PH, 1, ³¹P(P_A) = 517, ³¹P(P_B) = 424, and ³¹P(P_X) = 50; for X = CH₂, 4, ³¹P(P_A) = 611, ³¹P(P_B) = 450). The observed _exp ³¹P values for HP₄ ^- (Na/K, DME) completely disagree with the ³¹P calculated at GIAO/MP2/6-311+G(d) //RMP2(fc) /6-31+G(d) for structure 1. The rotational average of the phosphinidyltriphosphirene structures (P₃-PH^-, 3) agree better with the _exp ³¹P than those with a bicyclo[1.1.0]hydrogentetraphosphanide backbone, 2. MO analysis can rationalize the extreme endo/exo effect (³¹P = 455 ppm) on the chemical shift in the exocyclic PH group of 3. The lowest energy geometry of the anion 3 has E_rel of 31 kJ mol^-1 relative to 1. The most favored 3 + Na⁺ structure is only 15 kJ mol^-1 above the lowest energy HP₄Na minimum, 2 + Na⁺ with Na⁺ in endo and H in exo orientation of the bicyclo-P₄ framework (E_rel of 1 + Na⁺ is 13 kJ mol^-1). In most HP₄Na structures the Na⁺ changes the ³¹P NMR chemical shifts towards higher field with respect to the bare anions.Electronic Supplementary Material available.     

Die Verwertung reiner Nährstoffe

Auf der Grundlage einer Analyse von Energieumsatzmessungen an ausgewachsenen Rindern (Ochsen) bei Verfütterung von 110 Rationen sehr heterogener Nährstoffzusammensetzung werden folgende Vorhersagegleichungen für Brutto‐ (y₁), verdauliche (y₂) und umsetzbare Energie (y₃) sowie für die Energieansatzwirkung von Rationen (y) (kJ) mitgeteilt:

y₁ ‐ 23.6z₁ + 34.0z₂ + 17.3z₃ + 16,0z₄ + 19, 1z₅

y₂ = 23.6x₁ + 34.0x₂ + 17.3x₃ + 16.0x₄ + 18.0x₅

y₃‐ 17.3x₁ + 34.0x₂+15.9x₃+ 15.1x₄+15.4x₅

y = (6.5x₁ + 26.6x₂ + 10.1x₃ + 7.5x₄ + 8.9x_s)( ‐ 0.5574 + 0.04050x₆ ‐ 0,0002633x₆ ²)

z₁ = Rohprotein(g) x, ‐ verdl. Rohprotein(g)

z₂ ‐ Rohfett(g) x₂ = verdl. Rohfett(g)

z₃ ‐ Stärke(g) x₃ = verdl. Stärke(g)

z₄ ‐ Zucker(g) x₄ = verdl. Zucker(g)

z₅ ‐ N‐freie Reststoffe(g) x₅ = verdl. N‐freie Reststoffe(g)

x₆ ‐ Verdaulichkeit der Energie der Ration(%) (x₆ ≤ 77)     

STIMULATION BY THE SALTS OF THE NORMAL ALIPHATIC ACIDS IN THE ROCK BARNACLE BALANUS BALANOIDES

In Vol. 15, No. 6, July 20, 1932, page 620, in the first line under References, for J. Gen. Physiol., 1931–32, 15, 62, read J. Gen. Physiol., 1931–32, 15, 621.     

Novel steroidal 1,3,4-thiadiazines: Synthesis and biological evaluation in androgen receptor-positive prostate cancer 22Rv1 cells

A flexible approach to previously unknown spirofused and linked 1,3,4-thiadiazine derivatives of steroids with selective control of heterocyclization patterns is disclosed. (N-Arylcarbamoyl)spiroandrostene-17,6′ [1,3,4]thiadiazines and (N-arylcarbamoyl)17-[1′,3′,4′]thiadiazine-substituted androstenes, novel types of heterosteroids, were prepared from 16β,17β-epoxypregnenolone and 21-bromopregna-5,16-dien-20-one in good to high yields by the treatment with oxamic acid thiohydrazides. The synthesized compounds were screened for antiproliferative activity against the human androgen receptor-positive prostate cancer cell line 22Rv1. Most of (N-arylcarbamoyl)17-[1′,3′,4′]thiadiazine-substituted androstenes exhibit better antiproliferative potency (IC₅₀ = 2.1–6.6 µM) than the antiandrogen bicalutamide. Compounds 7d with IC₅₀ = 3.0 μM and 7j with IC₅₀ = 2.1 μM proved to be the most active in the series under study. Lead synthesized compound 7j downregulates AR expression and activity in 22Rv1 cells. NF-κB activity is also blocked in 7j-treated 22Rv1 cells. Apoptosis is considered as a possible mechanism of 7j-induced cell death.     

A THEORY OF INJURY AND RECOVERY : I. EXPERIMENTS WITH PURE SALTS.

In addition to the Correction in Vol. iii, No. 3, January 20, 1921, on page 149, Vol. iii, No. 2, November 20, 1920, line 13, for 92.57 read 89.10; page 154, lines 15, 28, and 32, for O read O+10; page 155, line 3 of the figure legend, for O read O+10.     

Modelling and off line optimization of batch gluconic acid fermentation

Summary The role of mathematical modelling and off line optimization for a batch fermentation process is described. The fermentation of gluconic acid by Acetobacter suboxydans ATCC 621 was studied. The model is based on a series of batch experiments in which the temperature was the only variable. The differential equations of the models were derived from these experiments to give the kinetic parameters and the parametric models varying with the temperature. The fermentation was optimized using Pontryagin's maximum principle. This gave the temperature profile of fermentation.Abbreviations x, g, l, S, c, P The concentration of cell mass, glucose, lactone, gluconic acid, 5-ketogluconic acid and total acidic products respectively - r₁, r₂ E₁ or E₂ enzyme in complex/total E₁ or E₂ enzyme content - a, b E₁ and E₂ enzyme content of unit quantity of biomass - k_i and K_j Rate constants - _max Maximum specific growth rate - y_x z₁=r₁x z₂=r₂x Yield coefficient of biomass with respect to growth on glucose - z₁ r₁x - z₂ r₂x     

Synthesis and conformational study of peptides possessing helically arranged ΔZPhe side chains

Z-Dehydrophenylalanine (Δ^zPhe) possessing four oligopeptides, Boc-(L -Ala-Δ^zPhe-Aib)_n-OCH₃ (n = 1–4: Boc, t-butoxycarbonyl; Aib, α-aminoisobutyric acid), were synthesized, and their solution conformations were investigated by ¹H-nmr, ir, uv, and CD spectroscopy and theoretical CD calculation. ¹H-nmr (the solvent accessibility of NH groups) and ir studies indicated that all the NH groups except for those belonging to the N-terminal L -Ala-Δ^zPhe moiety participate in intramolecular hydrogen bonding in chloroform. This suggests that the peptides n = 2–4 have a 4 → 1 hydrogen-bonding pattern characteristic of 3₁₀-helical structures. The uv spectra of all these peptides recorded in chloroform and in trimethyl phosphate showed an intense maximum around 276 nm assigned to the Δ^zPhe chromophores. The corresponding CD spectra of the peptides n = 2–4 showed exciton couplets with a negative peak at longer wavelengths, whereas that of the peptide n = 1 showed only weak signals. Theoretical CD spectra were calculated for the peptides n = 2–4 of several helical conformations, on the basis of exciton chirality method. This calculation indicated that the three peptides form a helical conformation deviating from the perfect 3₁₀-helix that contains three residues per turn, and that their side chains of Δ^z Phe residues are arranged regularly along the helix. The center-to-center distance between the nearest phenyl pair(s) was estimated to be ～ 5.5 Å. The chemical shifts of the Δ^zPhe side-chain protons (H^β and aromatic H) for the peptides n = 2–4 indicated anisotropic shielding effect of neighboring phenyl group(s); the effect also supports a regular arrangement of the Δ^z Phe side chains along the helical axis. © 1993 John Wiley & Sons, Inc.     

A signal-switchable fluorescent probe for detection of HPO42− based on 5,10,15,20-(4-sulphonatophenyl)porphyrin (TPPS4)

In this study, 5,10,15,20-(4-sulphonatophenyl)porphyrin (TPPS₄) was selected as a fluorescent probe due to its excellent characteristics including high quantum yield, good water solubility, and exceptional biocompatibility. With an excitation wavelength set at 515 nm, the optimal fluorescence emission wavelength for TPPS₄ was measured at 642 nm. At this moment, the fluorescence signal of TPPS₄ pink solution was in the ‘ON’ state. The fluorescence intensity of TPPS₄ was quenched when ascorbic acid (AA) was introduced, which was due to the electron transfer quenching effect between AA and TPPS₄. The colour of the corresponding solution changed from pink to green, and the fluorescence signal was in the ‘OFF’ state. When HPO₄²⁻ was further introduced into the TPPS₄–AA system, the quenched fluorescence intensity of TPPS₄ was recovered due to the unique interaction between HPO₄²⁻ and AA. At this time, the colour of the corresponding solution changed from green to red, and the fluorescence signal was in the ‘ON’ state. Therefore, an ‘ON–OFF–ON’ signal-switchable fluorescent probe was constructed based on TPPS₄ to detect HPO₄²⁻. The results showed that the linear range of HPO₄²⁻ was 4.0 × 10⁻⁹ to 1.7 × 10⁻⁶ M, and the detection limit was 1.3 × 10⁻⁹ M (S/N = 3). The sensing system exhibited high accuracy and sensitivity, and it could be used successfully to detect HPO₄²⁻ in real samples.     

Freezing Tolerance in Hydrated Lactuca sativa (L) Seed: A Model to Explain Observed Variation Between Seed Lots

On page 379 in line 7 of the legend to Fig. 4 the closed squareshould be an open square. On page 380, under the heading Survival of pierced seeds, line3 should read ‘...and 94 per cent respectively, aftercooling at 1 °C h^–1 to -20 °C with nucleationwicks. Apart from a small lesion...’     

Stable carbon and oxygen isotopes in human tooth enamel: Identifying breastfeeding and weaning in prehistory. Am. J. Phys. Anthropol. 106: 1–18.

ERRATUM: Wright LE and Schwarcz HP (1998) Stable Carbon and Oxygen Isotopes in Human Tooth Enamel: Identifying Breastfeeding and Weaning in Prehistory. Am. J. Phys. Anthropol. 106: 1–18. Isotopic ratios were incorrectly printed as percentages (%) rather than units permil (‰). Wherever “breast feeding” and “breast fed” occur, the words should be combined into “breastfeeding” and “breastfed” respectively. The correct information on isotopic ratios is the following: p. 1, Abstract: all % signs should be “‰”; p. 2, column two, last line: “… δ¹³C values¹, have been …”; p. 2, Footnote 1 should read: “Isotope ratios of carbon and oxygen are expressed in δ notation as follows, δ = [(R_sample/R_standard) − 1] × 1000, where R = ¹³C/¹²C for δ¹³C, and R = ¹⁸O/¹⁶O for δ¹⁸O, and are in units permil, ‰.”; p. 3, column two: all % signs should be “‰”, except for the 23rd line from the bottom, which reads: “… provided 95% of water intake by all infants …”; p. 5: all % signs should be “‰”; p. 6, column one: 8th and 9th line from bottom should be “… mean deviations were 0.029‰ for δ¹³C and 0.024‰ for δ¹⁸O …”; p. 6, column one: 2nd line from bottom should be “… only 0.208‰ for δ¹³C and only 0.091‰ for δ¹⁸O …”; p. 6, column two: top line: “… of 0.5‰ in δ¹³C and 0.2‰ in δ¹⁸O …”; p. 8, 9 and 10: all % signs should be “‰”; p. 11, column two: 7th line from top: “… the lipids are 4-6‰ lighter …”; p. 12, 13 and 14: all % signs should be “‰.”     

Substitutions of the Conserved Thr42 Increased the Roles of the ε-Subunit of Maize CF1 as CF1 Inhibitor and Proton Gate

The conserved residue Thr42 of -subunit of the chloroplast ATP synthase of maize (Zea mays L.) was substituted with Cys, Arg, and Ile, respectively, through site-directed mutagenesis. The over-expressed and refolded -proteins were purified by chromatography on DEAE-cellulose and FPLC on mono-Q column, which were as biologically active (inhibiting Ca²⁺-ATPase activity and blocking proton gate) as the native subunit isolated from chloroplasts. The T42C and T42R showed higher inhibitory activities on the soluble CF₁(–) Ca²⁺-ATPase than the WT. The T42I inhibited the Ca²⁺-ATPase activity of soluble CF₁ and restored photophosphorylation activity of membrane-bound CF₁ deficient in the most efficiently. Far-ultraviolet CD spectra showed that the portions of -helix and -sheet structures of the three mutants were somewhat different from WT. Thus the conserved residue Thr42 may be important for maintaining the structure and function of the -subunit and the basic functions of the -subunit as far as an inhibitor of Ca²⁺-ATPase and the proton gate are related.     

ERRATA

Page 806, Preparation of Mitochondrial Fraction, line 4: The following should be inserted between ‘centrifugedat’ and ‘20 000 g for’: 3000 for 10 mm. Thesupernatant was centrifuged at The following corrections are required: Page 104, line 20: ‘2-hydroxylation’ should read ‘2-ß3-hydroxylation’ Page 106, line 11: ‘of Ga₈’ should read ‘to GA₈’ Page 113, last line:‘length 50 µm’ shouldread ‘length 150 µm’ Formula 15 should read: Formula 17 should read: y(0)– y^* = ß₁V₁+ß₂V₂ page 118: Formula 18 should read: Formula 23 should read: Formula 24 should read:      

Over het gebruik van d-glutaminezuur bij het bacteriologische wateronderzoek

Samenvatting In het d-glutaminezuur werd een chemisch zuivere, relatief goedkoope stof gevonden, die het pepton in de voedingsbodems voor het bacteriologische wateronderzoek lijkt te kunnen vervangen; waarmede de moeilijkhedem uit de wereld zouden zijn, die, vooral bij het colionderzoek, kleven aan het gebruik van peptonen van verschillende herkomst. Hoewel het niet mogelijk bleek, de false presumptive tests geheel te vermijden, wordt toch het voordeel groot genoeg geacht om een proefneming op grooteren schaal in waterleidingbedrijven aan te bevelen.Summary The fact is stressed, that in bacteriological wateranalysis many false presumptive tests occur, where B. coli can not be isolated from strongly fermenting tubes. The view is held, that an improvement may be possible, when substituting peptone by a nitrogen compound, that is easily taken by B. coli and not by the organisms causing the false presumptive test. Therefore d-glutamic acid (as a sodium- or ammoniumsalt) is tried and found to be perfectly suitable to grow B. coli, but equally good to the other organisms. Nevertheless glutamic acid has a distinct advantage on peptone, being a chemically pure and relatively cheap substance, so that difficulties, arising from the use of different brands of commercial peptones, of unknown composition, may be avoided. Investigation of natural waters, using a solution of 1 % lactose, 1 % glutamic acid, 0.1% K₂HPO₄ and 0.05 % MgSO₄ in distilled water, coloured with bromo thymol blue and neutralised with sodium hydroxide to p₄ 7.0, gives the same results as the same liquid, wherein peptone (Witte) substitutes the glutamic acid. Further experience will have to decide on its suitability in large scale practice.