576

Specialia

6 simple geometric figures, t h e n to write down in a given order the results of the following 4 a r i t h m e t i c exercises: 3 single operations (division, multiplication or addition) and a c o m b i n a t i o n of 3 successive operations, each of all these operations being simple enough as to create no handicap for the b a c k w a r d pupils. This test was m e a n t to give us some indications of the influence of noise on the faculties of a t t e n t i o n and reasoning. The noise diffused during the t e s t s were either pure sounds of 40, 250, and 1000 H z respectively, or t h e following pre-recorded e n v i r o n m e n t noises: 1. traffic noise (in a noisy cross-road), 2. airplane noise (near the airport of Geneva-Cointrin) and 3. ' t e x t ' (a t e x t read w i t h the r h y t h m used for speech in the radio in order to simulate radio playing while the pupils are doing their home-work). A n u m b e r of m e t h o d s like the ' a r t i c u l a t i o n index' (AI) s, the 'speech interference level' (StL) 9 etc., h a v e been devised in order to e v a l u a t e the intelligibility of speech in the presence of various t y p e s of d e t e r m i n e d noises. I n this paper, we shall give all our results using the simpler dBA scale ~. The m e a n losses (in ~o) for each group and each test in the presence of t h e e n v i r o n m e n t noises m e n t i o n n e d at various levels (in the succession: 65, 55, 75 and 45 dBA respectively) are s u m m a r i z e d in the Table. Despite the small n u m b e r of subjects in the 2 groups, t h e following (statistically significant) results can be drawn: 1. The losses in performance of the future teachers are lower t h a n those of the pupils up to (and including) 65 dBA; at 75 dBa, a l t h o u g h increasing for b o t h groups, the losses a~e greater for the teachers. 2. A n o c i v i t y threshold (threshold where the losses s t a r t to increase more rapidly w i t h the elevation of the noise level) can be detected at around 55 dBA for the pupils and at around 65 dBA for t h e teachers. 3. As expected, in the first test the losses in

Effect of A s c o r b i c Acid on P i g m e n t a t i o n of T o a d

EXPERIENTIA32/5

the audition of logatoms are m u c h higher t h a n the losses in the a u d i t i o n of k n o w n words (which are in t u r n higher t h a n the losses in the audition of sentences)5. 4. W i t h regard to the first p a r t of t h e second test, we note t h a t t h e losses are low (except at 75 dBa); this result shows t h a t the faculty of a t t e n t i o n of b o t h groups is n o t distracted b y t h e noise (except at higher levels) because of the interest expressed b y the p a r t i c i p a n t s in performing those tests; it is therefore v e r y i m p o r t a n t to develop the m o t i v a t i o n of the pupils towards the t e a c h i n g t h e y receive. W h e n t h e two tests are c o n d u c t e d in the presence of disturbing pure sounds of 40, 250, and 1000 H z respect i v e l y (no t a b u l a t e d p r e s e n t a t i o n given here), the losses observed are m u c h lower t h a n those in t h e presence of e n v i r o n m e n t noises (which exhibit c o m p l e x spectra) and are more i m p o r t a n t at 250 H z t h a n at 1000 or 40 Hz. The losses calculated separately for the a d v a n c e d pupils and for t h e b a c k w a r d pupils indicate t h a t t h e a d v a n c e d pupils do m u c h b e t t e r t h a n the b a c k w a r d pupils; the differences, however, t e n d to vanish w i t h t h e elevation of the noise level a b o v e 55 dBA, especially for the losses in the audition of logatoms. A l t h o u g h this study, which will be published in more detail in F r e n c h elsewhere, should be e x t e n d e d to larger groups of pupils and teachers, we should like to draw once more the a t t e n t i o n of the t e a c h i n g staffs n o t only to the n o c i v i t y of noise in the school e n v i r o n m e n t , b u t also to the fact t h a t b a c k w a r d pupils resent t h e interference of noise to a m u c h higher degree t h a n the a d v a n c e d students.

8 N. R. FRENCH and J. C. STEINBERG, J. aeoust. Soc. Am. 19, 90 (1947); K. D. KRYTER, 3d, 1689 (1962). 9 L. L. BERANEK, Proc. Inst. Radio Engrs 35, 880 (1947).

(Bu]o melanostictus)

N. M. BISWAS and S. ROYCHAWDHURY 1

Department o/Physiology, Calcutta University, 92, Acharya Pra/ulla Chandra Road, Calcutta-700 009 (India), 25 August 1975. Summary. A d m i n i s t r a t i o n of ascorbic acid in t o a d during breeding season results an increase in melanin p i g m e n t s in skin, liver and vocal sac. The role of sex steroids in the synthesis of m e l a n i n p i g m e n t s has been r e p o r t e d in the rat * and bird 3. Previous in v i v o and in v i t r o studies indicate t h a t testicular steroid h o r m o n e synthesis in t o a d appears to be increased b y exogenous ascorbic acid (ASA)~-6. The influence of A S A on t h e p i g m e n t a t i o n in t o a d is obscure. A significant fall of A S A in the testis ~ and the melanin p i g m e n t s in t h e skin s has been observed in the h y p o p h y s e c t o m i z e d toad. F r o m these observations, it seemed desirable to d e t e r m i n e w h e t h e r A S A h a d a n y role in melanin formation in toad. Materials and methods. 16 male toads, weighing a b o u t 60 g, were used during t h e breeding season. The animals were divided into 2 groups of equal number. 1 group of animals received A S A (50 mg/100 g of b o d y weight) b y i.m. route. The remaining animals received 0.4 ml of a m p h i b i a n saline and were t r e a t e d as controls. 7 days after t r e a t m e n t animals were sacrificed simultaneously w i t h controls. The liver, vocal sac and the skin from dorsal surface were t a k e n separately from all the animals. Bio-

chemical s t u d y of melanin was carried b y spectrophotometric m e t h o d 9. The tissues were dried in a d e s i c c a t o r and digested w i t h pepsin for 24 h. The melanin granules were separated b y centrifugation and t h e n digested w i t h N a O H solution. The melanin c o n c e n t r a t i o n in solution was e x a m i n e d b y s p e c t r o p h o t o m e t e r after filtration. Results. The melanin p i g m e n t s were found to be present in the t o a d skin, liver and vocal sac. The 1 Acknowledgment. The authors' thanks are due to Prof. C. DEB, Head of the Department of Physiology, Calcutta University, for encouragements. 2 T. M. MILLS and E. SPAZlANI, Expl Cell. Res. 44, 13 (1966). 3 p. F. HALL, Sen. comp. Endocr. 2, 451 (1969). 4 N. M. BlswAs, Endocrinology 85, 981 (1969). 5 N. M. BlswAs, Endokrinologie 56, 144 (1970). 6 N. M. BlswAs and C. DEB, Endocrinology 87, 170 (1970). 7 N. M. BISWAS, Life Sci. 8, 363 (1969). s N. M. BISWAS, C. DEB, M. HAQUE and D. P. CHAKRABORTY, Endokrinologie 52, 271 (1967). " B. DAWES, Expl Biol. 78, 26 (1941).

15.5. 1976

Specialia

skin s h o w e d h i g h e r c o n c e n t r a t i o n of m e l a n i n p i g m e n t s t h a n t h e l i v e r a n d v o c a l sac. A d m i n i s t r a t i o n of A S A t o n o r m a l t o a d s p r o d u c e d a n i n c r e a s e in m e l a n i n c o n t e n t of skin, l i v e r a n d v o c a l sac c o m p a r e d t o saline t r e a t e d c o n t r o l s (Figure).

A)Skin :normal . . . . normal+AsA \ B)Liver 600 '~ ',, o onormal \ ~ . . . . normal+AsA 50C \ ~ C)V.Sac \ ~ o ~normal \ L,*----onormal+AsA 40C \ ~ 700 A)

:

8L - \ ' , ,

2001 C )

/

t

400 425

~ . - ~ : =

r

500 Wavelength

i

600

577

Discussion. T h e p r e s e n t s t u d y d e m o n s t r a t e s t h a t A S A causes a c o n s i d e r a b l e increase of m e l a n i n p i g m e n t s in t h e skin, l i v e r a n d v o c a l sac of toads. T h e possible m e c h a n i s m r e s p o n s i b l e for t h e a c t i o n of A S A o n m e l a n i n f o r m a t i o n h a s n o t b e e n e l u c i d a t e d . A S A in t h e t e s t i s 1~ a n d o t h e r tissues ( u n p u b l i s h e d o b s e r v a t i o n ) of t o a d s is k n o w n to b e oxidized t o d e h y d r o a s c o r b i c acid. O n t h e o t h e r h a n d d e h y d r o a s c o r b i c acid h e l p s in o x i d a t i o n - r e d u c t i o n of cell b y oxidizing t h e r e d u c e d g l u t a t h i o n e 11. I t is g e n e r a l l y a g r e e d t h a t t h e e n z y m e t y r o s i n a s e , w h i c h is r e s p o n s i b l e for m e l a n i n f o r m a t i o n , is i n h i b i t e d b y r e d u c e d g l u t a t h i o n e 1~. T h e p r e s e n c e of oxidized g l u t a t h i o n e in buffered t y r o s i n e - t y r o s i n a s e m i x t u r e increases m e l a n i n pigm e n t a t i o n ~a. F u r t h e r m o r e , d e h y d r o a s c o r b i c acid is k n o w n t o s t i m u l a t e s~eroid h o r m o n e s y n t h e s i s i n t o a d t e s t i s 6. FIGGE a n d ALLEN 13 h a v e r e p o r t e d t h a t local a p p l i c a t i o n of e s t r o g e n increases t h e skin p i g m e n t s . T h e y h a v e sugg e s t e d t h a t t h e e n z y m e t y r o s i n a s e oxidizes r i n g A of e s t r o n e t o a q u i n o n e w h i c h in p r e s e n c e of c o p p e r c a t a l y s t oxidizes t h e g l u t a t h i o n e . T h e p o s s i b i l i t y r e m a i n s , therefore, t h a t A S A in its o x i d i z e d f o r m ( d e h y d r o a s c o r b i c acid) s t i m u l a t e s m e l a n i n s y n t h e s i s b y o x i d i z i n g g l u t a t h i o n e e i t h e r d i r e c t l y or indirectly by increasing sexhormones.

,

650nm

The effect of ascorbic acid (ASA) on the melanin content of toad skin, liver and vocal sac. Melanin content of A) normal and ASA treated toad skin, B) normal and ASA treated toad liver and C) normal and ASA treated toad vocal sac.

10 N. M. BISWAS, Endokrinologie 57, 145 (1971). 11 L. W. MAPSON, Ann. N.Y. Acad. Sci. 92, 21 (1961). 12 F. H. J. FIGGE, Proc. Soc. exp. Biol. Med. 46, 269 (1941). 15 F. H. J. FlOCE and E. ALLEN, Endocrinology 29, 262 (1941).

Heartbeat Reversal and its Coordination with Accessory Pulsatile Organs and Abdominal in Lepidoptera

Movements

L. T. WASSERTHAL

Ruhr Universiti~t, Spezielle Zoologic, Buscheyslrasse, Postfach 2148, D-463 Bochum-Ouerenburg (German Federal Republic, BRD), 4 December 7975. Summary. H a e m o l y m p h in c e r t a i n L e p i d o p t e r a a t r e s t is p e r i o d i c a l l y t r a n s p o r t e d f r o m t h e a n t e r i o r b o d y t o t h e abd o m e n a n d r e v e r s e d b y t h e c o o r d i n a t e d a c t i v i t y of t h e h e a r t , t h e accessory pulsatile o r g a n s a n d t h e a b d o m e n . T h i s oscillatory h a e m o l y m p h t r a n s p o r t is s u g g e s t e d t o s u p p o r t h a e m o l y m p h e x c h a n g e a n d air v e n t i l a t i o n in t h e a n t e r i o r b o d y a n d wings. A l t h o u g h h e a r t b e a t r e v e r s a l h a s b e e n r e p e a t e d l y described in insects 1-7, i t is n o w g e n e r a l l y r e g a r d e d as b e i n g n o t e s s e n t i a l for c i r c u l a t i o n , b u t r a t h e r a d i s t u r b a n c e of h e a r t a u t o m a t i s m 6 , s or p e r h a p s a stress reactionS,% I n some r e c e n t papers, w h i c h deal w i t h t h e e l e c t r o p h y s i o l o g y of h e a r t r h y t h m in m o t h s , r e v e r s a l is e i t h e r n o t m e n tionedl0,11 or is r e g a r d e d as a r a r e a n d i r r e g u l a r e v e n t 1~. While mechanisms inducing and controlling heartbeat r e v e r s a l were t h e c e n t r a l p o i n t of i n t e r e s t s, 5, ~, la, l i t t l e h a s b e e n e l a b o r a t e d a b o u t its f u n c t i o n 2, is, 14 Results. A n e w m e t h o d , ' c o n t a c t - t h e r m o g r a p h y '15 (Figure 1), allows one t o e x a m i n e free, r e s t i n g i n s e c t s d u r i n g t h e i r whole l i f e t i m e w i t h o u t d a m a g e or n a r c o t i z a l i o n , so t h a t periodic h e a r t b e a t r e v e r s a l c o u l d be s h o w n t o b e a r e g u l a r p e r f o r m a n c e in p h a r a t e a n d a d u l t m o t h s (Attacus atlas L., Argema mittrei Gu6r., S a t u r n i i d a e , F i g ure 1) a n d b u t t e r f l i e s (Caligo brasiliensis Fldr., B r a s solidae) 15. S i m u l t a n e o u s r e c o r d i n g of t h e h e a r t , m e s o a n d m e t a t h o r a c i c p u l s a t i l e o r g a n s (PO's), w h i c h are r e s p o n s i b l e for t h e a d d u c t i o n of w i n g h a e m o l y m p h n,16

1 W. V. BUDDENBROCK, Vergleichende Physiologic Blur und Herz (Birkh~iuser, Basel uud Stuttgart 1967), voI. 6. 2 j. H. GEROULD, Aeta zool. 19, 297 (1938). 5 B. HEI•RICH, J. exp. Biol. 54, 153 (1971). 4 j. C. JoI~ES, in The Physiology o[ Insecta (Ed. ROCKS'rEIN; Academic Press, New York and London 1964), vol. 3. 5 F. V. 1V[cCANN,A. Rev. Ent. 75, 173 (1970). 6 S. M. TENI~EY, Physiologia comp. oecol. 3, 286 (1953). 7 j . F. YEAGER and G. O. HENDRICKSON, Ann. ent. Soc. Am. 27, 257 (1934). s V. B. WIGGLESWOHTH, The Principles o/ Insect Physiology, 7th edn. (Chapman and Hall, London 1972). 9 K. RICHTER, Zool. Jb. Abt. Physiol. 77, 477 (1973). 10 j . L. HANEGAN, J. exp. Biol. 59, 67 (1973). 11 R. MOREAUand L. LAVENSEAU,J. Insect. Physiol. 27, 1531 (1975). x5 y. QIJEINNEC and R. CAMPAN, J. Insect Physiol. 78, 1739 (1972). 13 M. TIRELLI, Archo. zool. ital. 22, 279 (1936). 14 T. YOKOYAMA,Bull. seric. Exp. Stn. Japan 8, 100 (1932). 15 L. T. WASSERTHAL,Verh. dt. zool. Ges. 197d, 95 (1975). 15 F. BROCHER, Archs Zool. exp. g6n. 60, 1 (1920).

Effect of ascorbic acid on pigmentation of toad (Bufo melanostictus).

Administration of ascorbic acid in toad during breeding season results an increase in melanin pigments in skin, liver and vocal sac...
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