A review of the primary types of the Hawaiian stag beetle genus Apterocyclus Waterhouse (Coleoptera,Lucanidae, Lucaninae), with the description of a new species

The species of the Hawaiian stag beetle genus Apterocyclus Waterhouse (Coleoptera: Lucanidae) are reviewed following an examination of all primary types. Although the continued existence of the species is unknown and some possibly are extinct there are five recently extant species, including one species that is described here as new. The holotypes for all available names are pictured, and synonymies discussed and updated. Lectotypes are designated for Apterocyclus honoluluensis Waterhouse and A. munroi Sharp. A key to species and a revised catalog for the genus are provided.     

Carotenoid binding sites in LHCIIb. Relative affinities towards major xanthophylls of higher plants.

The major light-harvesting complex of photosystem II can be reconstituted in vitro from its bacterially expressed apoprotein with chlorophylls a and b and neoxanthin, violaxanthin, lutein, or zeaxanthin as the only xanthophyll. Reconstitution of these one-carotenoid complexes requires low-stringency conditions during complex formation and isolation. Neoxanthin complexes (containing 30-50% of the all-trans isomer) disintegrate during electrophoresis, exhibit a largely reduced resistance against proteolytic attack; in addition, energy transfer from Chl b to Chl a is easily disrupted at elevated temperature. Complexes reconstituted in the presence of either zeaxanthin or lutein contain nearly two xanthophylls per 12 chlorophylls and are more resistant against trypsin. Lutein-LHCIIb also exhibits an intermediate maintenance of energy transfer at higher temperature. Violaxanthin complexes approach a xanthophyll/12 chlorophyll ratio of 3, similar to the ratio in recombinant LHCIIb containing all xanthophylls. On the other hand, violaxanthin-LHCIIb exhibits a low thermal stability like neoxanthin complexes, but an intermediate accessibility towards trypsin, similar to lutein-LHCIIb and zeaxanthin-LHCIIb. Binary competition experiments were performed with two xanthophylls at varying ratios in the reconstitution. Analysis of the xanthophyll contents in the reconstitution products yielded information about relative carotenoid affinities of three assumed binding sites. In lutein/neoxanthin competition experiments, two binding sites showed a strong preference (> 200-fold) for lutein, whereas the third binding site had a higher affinity (25-fold) to neoxanthin. Competition between lutein and violaxanthin gave a similar result, although the specificities were lower: two binding sites have a 36-fold preference for lutein and one has a fivefold preference for violaxanthin. The lowest selectivity was between lutein and zeaxanthin: two binding sites had a fivefold higher affinity for lutein and one has a threefold higher affinity to zeaxanthin.     

High temperature effects on photosynthesis and water relations of grain legumes

Effects of high temperature on photosynthesis, and its interaction with water relations in common bean (Phaseolus vulgaris), cowpea (Vigna unguiculata), faba bean (Vicia faba), and five cultivars of field pea (Pisum sativum) were investigated. Responses of all species were compared at 20/15, 30/15, or 30/25 °C day/night, and cowpea and pea were compared at 20/15 and 30/25 °C under well-watered and limited-water conditions. Response of pea to 20/15 and 30/25 °C during flowering was ascertained, and sensitivity of the photosystem of pea and faba bean to 40 °C was determined.High temperature decreased chlorophyll variable fluorescence (F_v), a measure of injury to photosynthesis, in all species except cowpea, which was highly tolerant. Leaf chlorophyll and most measures of growth were favored by high day temperature but not by high night temperature, and photosynthetic rates were enhanced by high temperatures that increased leaf chlorophyll and nitrogen (N) contents. High temperature diminished growth less than water deficiency and increased water use of all three species but only lowered the water potential in faba bean. Water deficiency generally decreased growth, water use, and water potential more at 30/25 °C than at 20/15 °C. Stress from high temperature during flowering of pea decreased all components of yield at maturity, particularly at nodes that flowered latest. Whole-chain photosynthetic activity in thylakoids of pea, faba bean, and wheat (Triticum aestivum) were equally sensitive to high temperature, suggesting that Photosystem Il was the most labile component. The results show that high temperature affects photosynthesis, growth, and water relations of grain legumes, and sensitivity to the stress differs among species and genotypes.     

Natural patterns of activity and long-term synaptic plasticity

Long-term potentiation (LTP) of synaptic transmission is traditionally elicited by massively synchronous, high-frequency inputs, which rarely occur naturally. Recent in vitro experiments have revealed that both LTP and long-term depression (LTD) can arise by appropriately pairing weak synaptic inputs with action potentials in the postsynaptic cell. This discovery has generated new insights into the conditions under which synaptic modification may occur in pyramidal neurons in vivo. First, it has been shown that the temporal order of the synaptic input and the postsynaptic spike within a narrow temporal window determines whether LTP or LTD is elicited, according to a temporally asymmetric Hebbian learning rule. Second, backpropagating action potentials are able to serve as a global signal for synaptic plasticity in a neuron compared with local associative interactions between synaptic inputs on dendrites. Third, a specific temporal pattern of activity--postsynaptic bursting--accompanies synaptic potentiation in adults.     

Two-step cell patterning on planar and complex curved surfaces by precision spraying of polymers

Controlling adhesion of living animal cells plays a key role in biosensor fabrication, drug-testing technologies, basic biological research, and tissue engineering applications. Current techniques for cell patterning have two primary limitations: (1) they require photolithography, and (2) they are limited to patterning of planar surfaces. Here we demonstrate a simple, precision spraying method for both positive and negative patterning of planar and curved surfaces to achieve cell patterns rapidly and reproducibly. In this method, which we call precision spraying (PS), a polymer solution is aerosolized, focused with sheath airflow through an orifice, and deposited on the substrate using a deposition head to create approximately 25 microm sized features. In positive patterning, adhesive molecules, such as laminin or polyethylenimine (PEI) were patterned on polydimethylsiloxane (PDMS) substrates in a single spraying operation. A variety of animal cell types were found to adhere to the adhesive regions, and avoid the non-adhesive (bare PDMS) regions. In negative patterning, hydrophobic materials, such as polytetrafluoroethylene (PTFE) and PDMS, were patterned on glass substrates. Cells then formed patterns on the exposed glass regions and avoided the hydrophobic regions. Cellular patterns were maintained for up to 2 weeks in the presence of serum, which normally fouls non-adhesive regions. Additionally, we found that precision spraying enabled micropatterning of complex-curved surfaces. Our results show that precision spraying followed by cell plating enables rapid and flexible cellular micropatterning in two simple steps.     

Synthese der T-antigenen trisaccharide O-β-d-galactopyranosyl-(1→3)-O-(2-acetamido-2-desoxy-α-d-galactopyranosyl)-(1→6)-d-galactopyranose und O-β-d-galactopyranosyl-(1→3)-O-(2-acetamido-2-desoxy-α-d-galactopyranosyl)-(1→6)-d-glucopyranose und deren anknüpfung an proteine

The synthesis of the trisaccharides O-β-d-galactopyranosyl-(1→3)-O-(2-acetamido-2-deoxy-α-d-galactopyranosyl)-(1→6)-d-galactopyranose (15) and O-β-d-galactopyranosyl-(1→3)-O-(2-acetamido-2-deoxy-α-d-galactopyranosyl)-(1→6)-d-glucopyranose (27) is described and the synthesis of α-d-glycosides by reaction of 3,4,6-tri-O-acetyl-2-azido-2-deoxy-β-d-galactopyranosyl chloride with highly reactive hydroxyl groups is discussed. The trisaccharide 27 was coupled with serum albumin by formation of an imine intermediate and reduced to an amine, to yield a synthetic T-antigen. A similar coupling of 15 was unsuccessful.     

Einfluß der syn-1,3-diaxialen wechselwirkung auf konformationsgleichgewichte der 2,4-diamino-2,4-didesoxy-α-d-idopyranose

Conformational equilibria of derivatives of 2,4-diamino-2,4-dideoxy-α-d-idopyranose are investigated. In the case of methyl 2,4-diacetamido-3,6-di-O-acetyl-2,4-dideoxy-α-d-idopyranoside, the proportion of the ¹C₄ conformation is between 7 and 44%, depending upon the solvent, and increases with increasing polarity of the solvent. Methyl 2,4-di(N-acetyl-N-acylamino)-3,6-di-O-acyl-2,4-dideoxy-α-d-idopyranosides show such strong steric 1,3-diaxial interaction that the proportion of the ¹C₄ conformation is 93%. Methyl 2,4-diamino-2,4-dideoxy-α-d-idopyranoside and its bis(ammonium) salt show strong 1,3-diaxial interactions of polar nature, resulting in an increase of the ¹C₄ conformation up to 74% and 84%, respectively.