Comparative analysis of methods for measurements of food intake and utilization using the soybean looper, Pseudoplusia includens and artificial media

An analysis of intake and utilization of an artificial medium by larvae of the soybean looper, Pseudoplusia includens Walker, Lepidoptera: Noctuidae, was performed using 4 methods: standard gravimetric, chromic oxide, Calco Oil Red, and ¹⁴C-glucose. Each method was used in conjunction with standard gravimetry. The relative merits of the indirect methods were analyzed in terms of precision and accuracy for ECI and ECD estimation, cost, and overall versatility. Only the gravimetric method combined ca. 80% precision in ECI and ECD estimation with low cost and maximum versatility. Calco Oil Red at 0.1% w/v was detrimental to the larvae. Cr₂O₃ caused reduced intake but conversion was increased resulting in normal development and growth of larvae. The radioisotopic method had the advantage of providing a direct means of measuring expired CO₂. The need to operate under a totally enclosed system, however, poses some serious difficulties in the use of radioisotopes. There seems to be little advantage in any of the proposed indirect methods, except if there are unusual difficulties in separating the excreta from the medium.Supported in part by the Brazilian Programa de Ensino Agricola Superior (PEAS/Michigan State University Contract); by NSF and EPA through grant (NSF GB-37418) to the University of California; and USDA-SEA grant 616-15-68. The findings and opinions expressed herein are those of the authors and not necessarily those of the sponsoring agencies or institutions.     

Molecular weight of starch synthetase from Oryza sativa leaves

Soluble ADP-glucose: α-1,4-glucan-4-glucosyltransferase with primed activity was extracted from rice leaves and purified by (NH₄)₂SO₄ fractionation, gradient elution on DEAE-cellulose and finally by Sephadex G200 gel filtration or amylopectin-cellulose chromatography. The purified enzyme was essentially homogeneous electrophoretically, but exhibited two peaks corresponding to MW of 22 000 and 67 000 on Sephadex G200 chromatography and five distinct bands on sodium dodecyl sulfate gel electrophoresis with MW of 11·5, 20, 35, 50 and 68 × 10³.     

Topological biology: A note on Rashevsky's transformation T.

In the bio-topological transformation between graphs denoted by (T ⁽¹⁾ X) N. Rashevsky (Bull. Math. Biophysics,18, 173–88, 1956) considers the number of fundamental sets which (a) have only one specialized point as source (and no other sources), (b) have no points in common (are “disjoined”); he proves that this number is an invariant of the transformation. In this note we show that Rashevsky's Theorem can be extended as follows:The number of fundamental sets of the first category is an invariant of the transformation. We must, however, count the subsidiary points of the transformed graph as specialized points. We recall that fundamental sets of the first category are those whose sources consist of specialized points only (Trucco,Bull. Math. Biophysics,18, 65–85, 1956). But in this modified version of the Theorem the fundamental sets may have more than one source and need not be disjoined.     

Note on a combinatorial problem

In the first part of this paper we have assembled some properties of the quantitiesR _m ⁿ , whereR _m ⁿ denotes the number of distributions ofn different objects intom indifferent parcels, with no empty parcels allowed. We then discuss the following problem (N. Rashevsky, 1954, 1955 a,b, 1956): to find the total number,G _n , of graphs that can be obtained from the biotopological transformation (T ⁽¹⁾ X) for a given value of the parametern. This is related to the distribution ofn indifferent objects intom different boxes. A formula forG _n is given which, however, is not very convenient for practical computations because it involves a summation over certain “admissible partitions” of the numbermn (m is a second parameter of the transformation). Some theorems are derived; with their help we can simplify the calculation ofG _n to a small extent. The numbersG _n are calculated forn≤9 and estimated forn=10. It is found thatG ₇≈5.4×10⁴,G ₈≈8.3×10⁵,G ₉≈1.4×10⁷, andG ₁₀≈3×10⁸. These values ofn are those which might be used in connection with N. Rashevsky’s work (cf. Rashevsky, 1956).     

Short-term ecological consequences of a major oil spill on Panamanian subtidal reef corals

A major oil spill (8,000,000 liters; 50,000 barrels) occurred in Bahía Las Minas on the Caribbean coast of Panama in April 1986, and oil slicks from the refinery landfill and mangroves were still common there after 21/2 years. We studied short-term effects of the spill on common shallow subtidal reef corals, at the individual, population, and community levels. Numbers of corals, total coral cover, and species diversity based on cover decreased significantly with increased amounts of oiling. Cover of the large branching coral Acropora palmata decreased most. Frequency and size of recent injuries on massive corals increased with level of oiling, particularly for Siderastrea siderea. Growth of three massive species (Porites astreoides, Diploria strigosa, and Montastrea annularis, but not S. siderea) was less at oiled reefs in the year of the spill than during the 9 previous years. Subtidal coral reefs, particularly those along protected coasts, may suffer extensive damage from chronic exposure after major oil spills. Mailing Address from the USA: Smithsonian Tropical Research Institute, APO Miami 34002-0011, USA     

Anion transport in rat brain mitochondria: Fumarate uptake via the dicarboxylate carrier

Penetration of fumarate into rat brain mitochondria has been investigated, as required in brain ammoniogenesis. Mitochondria swell in ammonium fumarate and this swelling is increased by both Pi and malate. According to a carrier mediated process, fumarate translocation, which occurs in exchange with intramitochondrial malate or Pi shows saturation characteristics. By photometrically investigating the kinetics of fumarate/malate, fumarate/ Pi and malate/Pi exchanges, different Km values were obtained (10, 22 and 250 M, respectively), whereas no significant difference was found forV _max values (40 nmol NAD(P)⁺ reduced/min×mg protein). This suggests that fumarate and malate share a single carrier to enter mitochondria, namely the dicarboxylate carrier. Both comparison made of theV _max values and inhibiton studies exclude a fumarate translocation via either the tricarboxylate carrier, whose occurrence in brain is here demonstrated, or oxodicarboxylate carrier. Kinetic investigation of the dicarboxylate translocator shows the existence of thiol group/s and metal ion/s at or near the substrate binding sites. The experimental findings are discussed in the light of fumarate uptake in vivo in brain ammoniogenesis.Abbreviations AD.SUCC adenylsuccinate - ASP aspartate - BTA 1,2,3,-benzenetricarboxylate - CITR citrate - D-NAD deamino-NAD - PUM fumarate - GABA -aminobutyrate - GAP glyceraldehyde-3-phosphate - GAP-DH glyceraldheyde-3-phosphate dehydrogenase - GHBA -hydroxybutyrate - HEPES 4-(2-hydroxyethyl)-1-piperazine ethanesulfonic acid - OAA oxaloacetate - OG oxoglutarate - PEP phosphoenolpyruvate - 3-PG glycerate-3-phosphate - 3-PGP glycerate-1,3-diphosphate - PYR pyruvate - RBM rat brain mitochondria - RHM rat heart mitochondria - RKM rat kidney mitochondria - RLM rat liver mitochondria - SSA succinic semialdehyde     

Effect of water stress on abundance of twospotted spider mite on soybeans under greenhouse conditions

A rope wick technique was used to establish different levels of water stress in potted, greenhouse-grown soybean, Glycine max (L.) Merrill, plants. Water stress reduced, within a single generation, the overall abundance (number of mites/cm² leaf) of the twospotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae) and particularly influenced female mites and eggs. Mites were most numerous in the upper strata of soybean plants on youger and possibly more nutritious leaves.

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Influence de l'arrosage sur l'abondance de Tetranychus urticae sur soja, Glycine max en serre

Résumé Un arrosage par capillarité contrôlé a été utilisé pour maintenir différentes teneurs en eau dans des pieds empotés de G. max. Le stress hydrique a réduit, en une génération, la densité de T. urticae (nombre d'acariens/cm² de feuille), et particulièrement celle des femelles et des oeufs. Les acariens étaient plus nombreux sur les feuilles les plus jeunes et peut-être les plus nutritives des strates supérieures des pieds de soja.

     

Biaryl piperidines as potent and selective delta opioid receptor ligands

The design and synthesis of novel opiates are reported. Based on the message-address principle a novel class of 4,4- and 3,3-biaryl piperidines was designed and synthesized. Biological evaluation confirmed that these compounds exhibit high affinity and selectivity for the delta opioid receptor. Key structure–activity relationships that influence affinity, selectivity, functional activity and clearance are reported.     

Birds and army ants in a fragment of the Atlantic Forest of Brazil

ABSTRACT Little is known about the birds associated with army‐ant swarms in the Brazilian Atlantic forest. Our objectives were to locate and monitor army‐ant swarms in the Atlantic rainforest of Brazil and to identify the species of birds that attended the swarms and exhibited bivouac‐checking behavior. From July 2004 to August 2005, we located 49 swarms of army ants, including 28 Eciton burchelli, 19 Labidus praedator, and 2 Eciton vagans swarms. No birds were present at 17 (35%) swarms. At 32 swarms where birds were present, 22 (69%) were E. burchelli swarms and 10 (31%) were L. praedator swarms. No birds were observed at the two E. vagans swarms. We identified 66 species of birds attending the swarms, but only 43 species were observed foraging on prey flushed by the ants. Eighteen of these species had not been previously reported to forage in association with army‐ant swarms. Most birds observed during our study attended army‐ant swarms opportunistically, with White‐shouldered Fire‐eyes (Pyriglena leucoptera) the only obligate ant follower. Our observations suggest that the arthropods and other organisms flushed by army ants represent an important food resource for several species of birds in the Atlantic forest ecosystem.     

Human β-defensin 1: A restless warrior against allergies,infections and cancer

Human β-defensin 1 (hBD-1) is probably the most important antimicrobial peptide in epithelial tissues. Its alleles and/or altered gene expression have been associated with at least 20 human diseases. hBD-1 is a tumor suppressor and DEFB1 is the only innate immunity gene that shows long-term balanced selection and heterozygote advantage. It is unique in its constitutive expression, but is still capable of upregulation upon inflammatory or microbial stimuli. The present minireview focuses on hBD-1 properties, biological function, its proposed pathogenic mechanisms and the potential uses of elicitors, inhibitors or the peptide itself in the treatment of hBD-1-related human diseases including allergies, infections and cancer.