Untersuchungen zur ernährungsphysiologischen Bedeutung von NPN-Verbindungen

The aims of the experiment were to investigate the variation in ruminal fermentation, milk performance and milk fatty acid profile triggered by induced subacute ruminal acidosis (SARA); and to evaluate the ability of beet pulp (BP) as a replacement for ground maize in order to alleviate SARA. Eight Holstein-Friesian cows were fed four diets (total mixed rations) during four successive periods (each of 17 d): (1) without wheat (W0); (2) with 10% finely ground wheat (FGW) (W10); (3) with 20% FGW (W20); (4) with 20% FGW and 10% pelleted BP (BP10). Inducing SARA by diet W20 decreased the daily mean ruminal pH (6.37 vs. 5.94) and the minimum ruminal pH (5.99 vs. 5.41) from baseline to challenge period. Ruminal concentrations of total volatile fatty acid, propionate, butyrate, valerate and isovalerate increased with the W20 compared with the W0 and W10 treatments. The substitution of BP for maize increased the minimum ruminal pH and molar percentage of acetate and decreased the molar percentage of butyrate. The diets had no effect on dry matter intake (DMI) and milk yield, but the milk fat percentage and yield as well as the amount of fat-corrected milk was reduced in the W20 and BP10 treatments. The cows fed the W20 diet had greater milk concentrations of C11:0, C13:0, C15:0, C14:1, C16:1, C17:1, C18:2n6c, C20:3n6, total polyunsaturated fatty acids (FA) and total odd-chain FA, and lower concentrations of C18:0 and total saturated FA compared with the cows fed the W0 diet. Therefore, it can be concluded that changes in ruminal fermentation, milk fat concentration and fatty acid profile are highly related to SARA induced by feeding high FGW diets, and that the substitution of BP for maize could reduce the risk of SARA in dairy cows.     

The calmodulin binding domain of the plasma membrane Ca2+ pump interacts both with calmodulin and with another part of the pump

Synthetic peptides corresponding to the calmodulin-binding domain of the human erythrocyte Ca2+ pump were prepared representing residues 2-29 (C28W), 2-21 (C20W), 2-16 (C15W), and 16-29 (C14) of the sequence (James, P., Maeda, M., Fisher, R., Verma, A. K., Krebs, J., Penniston, J. T., and Carafoli, E. (1988) J. Biol. Chem. 263, 2905-2910). Peptides C28W, C20W, and C15W bound to calmodulin with an apparent 1:1 stoichiometry in the presence of Ca2+ and inhibited the activation of the Ca2+ pump by calmodulin, while C14 was ineffective. Substituting tyrosine (C28Y) or alanine (C28A) for the tryptophan residue lowered the affinity for calmodulin. The estimated Kd values for the calmodulin-peptide complexes were 0.1 nM for C28W, 5-15 nM for C20W, C28Y, and C28A, and 700-1700 nM for C15W. The Ca2+ pump in inside-out erythrocyte membrane vesicles was activated by proteolytic removal of the endogenous calmodulin-binding domain. Addition of C20W or C28W then inhibited calmodulin-independent Ca2+ transport, while a calmodulin-binding peptide from another enzyme had no effect. The inhibition of the pump by C20W was purely competitive with Ca2+, while C28W decreased the Vmax and increased the K1/2 for Ca2+, restoring the pump activity nearly to its low basal level. The results suggest that a calmodulin-binding peptide from any enzyme has two kinds of specificity: it shares with peptides from other enzymes the ability to bind to calmodulin, but only it has the specificity to interact with its own (proteolytically activated) enzyme.     

Reviews

Book reviewed in this article:
Plant Molecular Biology. Molecular Genetic Analysis of Plant Development and Metabolism. Ed. by G loria C oruzzi & P ere P uigdomégnech
Vacuum Methods in Electron Microscopy. By W. C. B igelow . Practical Methods in Electron Microscopy. Vol 15. Series Editor: Audrey M. G lauert .
The Fungi. By M ichael J. C arlile & S arah C. W atkinson .
Aspects of Tropical Mycology. Symposium of the British Mycological Society held at the University of Liverpool, April 1992. Edited by S. I saac , J. C. F rankland , R. W atling & A. J. S. W halley .
Belalong, A Tropical Rainforest. By T he E arl O f C ranbrook & D avid S. E dwards .
Ecology and Management of Invasive Riverside Plants. Ed. by L. C. D e W aal , L. E. C hild , P. M. W ade & J. H. B rock     

Reviews

Book reviewed in this article:
Quantitative Zoology. By G. G. S impson and A. R oe .
Elements of Plant Pathology. By I. E. M elhus and G. C. K ent .
Experiments in Plant Physiology. A Laboratory Textbook. By W. E. Loomis and C. A. Shull.
Seed and Potting Composts: with Special Reference to Soil Sterilization. By W. J. C. L awrence and J. N ewell .
Practical Plant Breeding . By W. J. C. L awrence .
Recent Advances in Plant Genetics . By F. W. S ansome and J. Philp. 2nd edition, revised and rewritten by F. W. S ansome .
The Evolution of Genetic Systems. By C. D. D arlington .     

Wearing a cooling jacket during exercise reduces thermal strain and improves endurance exercise performance in a warm environment

The aim of the present study was to investigate the effect of wearing a cooling jacket on thermoregulatory responses and endurance exercise performance in a warm environment. Nine untrained male subjects cycled for 60 minutes at 60% Vo(2)max (Ex1) and then immediately exercised to exhaustion at 80% Vo(2)max (Ex2) in 32.0 +/- 0.2 degrees C and 70-80% relative humidity. Four separate conditions were set during exercise: no water intake (NW), water intake (W), wearing a cooling jacket (C) and the combination of C and W (C+W). Rectal temperatures (T(re)) before Ex1 were not different between the 4 conditions, whereas at the end of Ex1 T(re) of C+W was significantly lower than the C and W (p < 0.05). Mean skin temperature (T(sk)) was significantly lower in C and C+W than the NW and W during Ex1. Heart rate of C and C+W were significantly lower than the NW and W, and rating of perceived exertion (RPE) in C+W was lower than in the other conditions. Exercise time to exhaustion was significantly longer in C+W than in the other conditions (NW < W, C < C+W; p < 0.05), whereas T(re) at exhaustion was not different. Our results indicate that the combination of wearing a cooling jacket and water intake enhances exercise endurance performance in a warm environment because of a widened temperature margin before the critical limiting temperature is reached and also because of decreased thermoregulatory and cardiovascular strain.     

BUCHBESPRECHUNGEN

Book reviewed in this article:
E rben , H. K.: Die Entwicklung der Lebewesen. Spielregeln der Evolution. R einboth , R. (Ed.): Intersexuality in the Animal Kingdom.
The Sea Urchin Embryo. Biochemistry and Morphogenesis. Hrsg. von G. C zihak unter Mitwirkung von R. P eter . Vorwort von J. B rachet .
The Blood of Sheep. Composition and Function. Ed. by M. H. B lunt . With contributions by M. H. B lunt , R. I. C ox , C. C. C urtain , J. D. D argie , K. A. F erguson , P. H. H olmes , T. H. J. H uisman , W. M. F. L eat , D. B. L indsay , W. V. M acfarlane , E. W. M oodie and E. M. T ucker .
S tephan , H.: Allocortex. Handbuch der mikroskopischen Anatomie des Menschen. Begründet von W. v. M öllendorf , fortgeführt von W. B argmann . Bd. 4, Teil 9.     

Large differences in peak oxygen uptake do not independently alter changes in core temperature and sweating during exercise

The independent influence of peak oxygen uptake (Vo(? peak)) on changes in thermoregulatory responses during exercise in a neutral climate has not been previously isolated because of complex interactions between Vo(? peak), metabolic heat production (H(prod)), body mass, and body surface area (BSA). It was hypothesized that Vo(? peak) does not independently alter changes in core temperature and sweating during exercise. Fourteen males, 7 high (HI) Vo(? peak): 60.1 ± 4.5 ml·kg?1·min?1; 7 low (LO) Vo(? peak): 40.3 ± 2.9 ml·kg?1·min?1 matched for body mass (HI: 78.2 ± 6.1 kg; LO: 78.7 ± 7.1 kg) and BSA (HI: 1.97 ± 0.08 m2; LO: 1.94 ± 0.08 m2), cycled for 60-min at 1) a fixed heat production (FHP trial) and 2) a relative exercise intensity of 60% Vo(? peak) (REL trial) at 24.8 ± 0.6°C, 26 ± 10% RH. In the FHP trial, H(prod) was similar between the HI (542 ± 38 W, 7.0 ± 0.6 W/kg or 275 ± 25 W/m2) and LO (535 ± 39 W, 6.9 ± 0.9 W/kg or 277 ± 29 W/m2) groups, while changes in rectal (T(re): HI: 0.87 ± 0.15°C, LO: 0.87 ± 0.18°C, P = 1.00) and aural canal (T(au): HI: 0.70 ± 0.12°C, LO: 0.74 ± 0.21°C, P = 0.65) temperature, whole-body sweat loss (WBSL) (HI: 434 ± 80 ml, LO: 440 ± 41 ml; P = 0.86), and steady-state local sweating (LSR(back)) (P = 0.40) were all similar despite relative exercise intensity being different (HI: 39.7 ± 4.2%, LO: 57.6 ± 8.0% Vo(2 peak); P = 0.001). At 60% Vo(2 peak), H(prod) was greater in the HI (834 ± 77 W, 10.7 ± 1.3 W/kg or 423 ± 44 W/m2) compared with LO (600 ± 90 W, 7.7 ± 1.4 W/kg or 310 ± 50 W/m2) group (all P < 0.001), as were changes in T(re) (HI: 1.43 ± 0.28°C, LO: 0.89 ± 0.19°C; P = 0.001) and T(au) (HI: 1.11 ± 0.21°C, LO: 0.66 ± 0.14°C; P < 0.001), and WBSL between 0 and 15, 15 and 30, 30 and 45, and 45 and 60 min (all P < 0.01), and LSR(back) (P = 0.02). The absolute esophageal temperature (T(es)) onset for sudomotor activity was ～0.3°C lower (P < 0.05) in the HI group, but the change in T(es) from preexercise values before sweating onset was similar between groups. Sudomotor thermosensitivity during exercise were similar in both FHP (P = 0.22) and REL (P = 0.77) trials. In conclusion, changes in core temperature and sweating during exercise in a neutral climate are determined by H(prod), mass, and BSA, not Vo(? peak).     

REVIEWS

Diseases of Fruits and Hops. By H. W ormald .
Nytteplanter. By K. G ram , H. J. J ensen and A. M entz .
Poisonous Plants of the United States. By W. C. M uenscher .
Introduction to the Botany of Field Crops. By Prof. J. M. H ector .
Commercial Fruit and Vegetable Products: a Textbook for Student, Investigator and Manager. By W. V. C ruess .
The Rape of the Earth: A World Survey of Soil Erosion. By G. V. J acks and R. O. W hyte .
Science in Africa: A Review of Scientific Research relating to Tropical and Southern Africa. By E. B. W orthington .
Health and Nutrition in India. By N. G angulee .
An Introduction to Modern Genetics. By C. H. W addington .
Earth's Green Mantle. By S. M angham .     

Book Reviews

Book reviewed in this article:
LINGUISTICS AND FOLKLORE: Alpha: The Myths of Creation. C harles H. L ong
LINGUISTICS AND FOLKLORE: The Two Hands oj God: The Myths of Polarity . A lan W. W atts . (Patterns of Myth and Experience. A lan W. W atts , ed.)
LINGUISTICS AND FOLKLORE: The Wisdom of the Serpent: The Myths of Death, Rebirth, and Resurrection . J oseph L. H enderson , and M aud O akes     

REVIEWS

Book reviewed in this article:
Principles of Soil Microbiology. By S elman A. W aksman
The Microbiology of Cellulose, Hemicelluloses, Pectin and Gums. By A. C. Thaysen and H. J. Bunker
Standard Methods of the Division of Laboratories and Research of the New York State Department of Health. By A. P. W adsworth
Schädlingsbehämpfung. Grundlagen und Methoden in Pflanzenschutz. V on D r W alther T rappmann
Agricultural Parasitology. By C. L. W alton and W. R ees W right     

Reconstructing Human Origins: A Modern Synthesis

Reconstructing Human Origins:. Modern Synthesis. Glenn C. Conroy. New York: W. W. Norton and Company, 1997.557 pp.     

REVIEWS

B ehavioral B iology of K iller W hales . Barbara C. Kirkevold and Joan S. Lockard, eds.
A rctic W halers , I cy S eas . N arratives of the D avis S trait W hale F ishery . W. Gillies Ross.
B ibliographie Ü ber W al -B ibliographie . C etacea . B ibliography on W hale -B ibliographies . Franz W. Bekierz.
R ight W hales : P ast and P resent S tatus . P roceedings of the W orkshop on the S tatus of R ight W hales . Robert L. Brownell, Jr., Peter B. Best and John H. Prescott (eds.).
O rdering the O ceans . Clyde Sanger.     

Book Reviews

Book reviewed in this article:
O ther : Cooperation among Animals with Human Implications by W. C. A llee .
O ther : Methodology and Techniques for the Study of Animal Societies by J. P. S cott , J ohn B. C alhoun , C. R. C arpenter , N. E. C ollins , J ohn T. E mlen , J. L. F uller , L eonard J. G oss , L awrence I rving , B ernard F. R iess , T. C. S chneirla , and J ohn W. S cott .
O ther : Of Societies and Men by C aryl P. H askins .     

Book Reviews

Books reviewed in this article:
AGRICULTURAL ECOLOGY: an analysis of world food production systems G.W. C ox & M.D. A itkens (1979) Hardback
PLANT CELL CULTURES: RESULTS AND PERSPECTIVES . Edited by F. S ala , B. P arisi , R. C ella & O. C iferri .
INTRODUCTION TO MODERN MYCOLOGY . By J.W. D eacon . (1980)     

Book Reviews

Books review in this article:
Life in Moving Fluids (2nd revised and expanded edition). S teve V ogel (1994)
Water Quality and Stress Indicators in Marine and Freshwater Ecosystems: Linking Levels of Organisation . E dited by D.W. S utcliffe (1994)
Handbook on Ecotoxicology-Volume 1 . Edited by P eter C alow
Acidification of Freshwater Ecosystems; Implications for the Future . Edited by C.E.W. S teinberg & R F. W right     

REVIEWS

Organization and Evolution in Plants . By C. W. W ardlaw
Spring Wildflowers of the San Francisco Bay Region . By H elen K. S harsmith
The Mineral Nutrition of the Rice Plant
Nutritional Values in Crops and Plants . By W erner S chuphan
The Identification of Flowering Plant Families . By P. H. D avis and J. C ullen
Morphologic Encyclopedia of Palynology; An International Collection of Definitions and Illustrations of Spores and Pollen . By G erhard O. W. K remp
Biological Statistics: An Introduction . By S. C. P earce
The Evolution of Biology . By M. J. S irks and C onway Z irkle     

Books

Book reviews in this article:
H andbook of M arine M ammals . V olume 3: T he S irenians and B aleen W hales . S. H. Ridgway and R. Harrison (eds.).
L es P hoques M oines -M onk S eal . Ronald and R. Duguy (eds.).
T he E lements of G raphing D ata . W. S. Cleveland.
G uia P ara el R econocimiento de C etaceos del M ar A rgentino . A. Lichter and A. Hooper.
M amiferos M arinos de C hile . W. Sielfeld K.
T he W hale W atcher's H andbook . E. Hoyt. Illustrations by P. Folkens.
W hales and D olphins of N ew Z ealand and A ustralia : A n I dentification G uide . A. N. Baker.     

3种无脊椎动物对近江牡蛎Crassostrea ariakensis和熊本牡蛎C. sikamea的捕食研究

捕食是影响牡蛎种群建立和牡蛎礁发育的重要生物因子之一。通过室内受控实验测定了日本蟳（Charybdis japonica）、脉红螺（Rapana venosa）和黄口荔枝螺（Thais luteostoma）对4组规格（W1：壳高10-20mm;W2：壳高20-30mm;W3：壳高30-40mm;W4：壳高>40mm）近江牡蛎（Crassostrea ariakensis）和熊本牡蛎（C.sikamea）的捕食偏好性和捕食效率。双因子方差分析结果表明,日本蟳对2种牡蛎的捕食效率没有显著性差异（P>0.05）,但牡蛎规格大小显著影响着日本蟳的捕食效率（P<0.05）,即日本蟳对W1组近江牡蛎的捕食效率显著高于W2和W4组（P<0.05）,W3组的被捕食效率介于中间（P>0.05）;日本蟳对W1组熊本牡蛎的捕食效率显著高于W2和W3组（P<0.05）,W4组的被捕食效率与其他处理组均没有显著性差异（P>0.05）。牡蛎种类（P=0.590）和规格大小（P=0.357）对脉红螺的捕食效率均无显著性影响,不同规格的两种牡蛎均呈现较低的被捕食效率。黄口荔枝螺对2种牡蛎的捕食效率无显著性差异（P=0.917）,但牡蛎规格大小显著影响其捕食效率（P=0.035）,即对W1组熊本牡蛎捕食效率显著高于其他3个规格组（P<0.05）,但其对不同规格近江牡蛎的捕食效率没有显著性差异（P>0.05）。2种牡蛎的壳厚与其壳高之间均存在极显著的正相关关系（P<0.001）。研究结果表明,3种无脊椎动物捕食者对近江牡蛎和熊本牡蛎并未表现出差异性的捕食偏好,但对不同规格牡蛎的捕食效率具有种间差异。     

微水体系中荧光假单胞菌脂肪酶催化合成单甘酯

研究了无溶剂微水体系中荧光假单胞菌脂肪酶 (PFL)催化油脂甘油解合成单甘酯的反应因素以及多温程非均相固液反应对单甘酯产率的影响。以初始体系最低共熔点 (PFL)取代临界温度学说中的油脂初熔点 ,通过考察不同IEP体系的甘油解 ,发现PFL酶促油脂甘油解时存在碳链基质特异性的函数关系 ,即反应物油脂中饱和碳残基的质量百分含量 (C₁₆+C₁₈)与单甘酯产率间符合以下多项式:Y =- 0.0006X³ +0.0592X²-0.8909X+26.753(13%<X<76.5%),式中X为C₁₆+C₁₈,Y为40℃时等温反应条件下的单甘酯产率。IEP为40℃时,最适等温反应条件如下：加水量3%～4.5%,加酶量为500μ/g油酯摩尔比1：2.5-5.0(油酯：甘油)反应温度40℃.实验条件下多步等程序降温反应48h后单甘酯最高产率为81.4%.     

Book Review

Books reviewed in this article:
ALGAL DEVELOPMENT: MOLECULAR AND CELLULAR ASPECTS. Edited by W. W eissner , D. G. R obinson & R. C. S tarr