BIRD PREDATION AS A SELECTIVE AGENT IN A BUTTERFLY POPULATION

In a population of the checkerspot butterfly, Euphydryas chalcedona, the detached wings of 309 individuals that had been attacked and eaten by birds were collected during a single flight season. During this time period a representative sample of 296 live butterflies in this population was photographed. Comparison of sex ratio and coloration of those butterflies that had been attacked with those that had not showed, first, that birds attacked slightly more females than males; and second, that among males, which are extremely variable in the amount of red on the forewing, birds attacked the less red individuals.     

Internal Medicine: Ventilator Management of Severe Asthma

The Scientific Board of the California Medical Association presents the following inventory of items of progress in internal medicine. Each item, in the judgment of a panel of knowledgeable physicians, has recently become reasonably firmly established, both as to scientific fact and important clinical significance. The items are presented in simple epitome, and an authoritative reference, both to the item itself and to the subject as a whole, is generally given for those who may be unfamiliar with a particular item. The purpose is to assist busy practitioners, students, researchers, or scholars to stay abreast of these items of progress in internal medicine that have recently achieved a substantial degree of authoritative acceptance, whether in their own field of special interest or another.The items of progress listed below were selected by the Advisory Panel to the Section on Internal Medicine of the California Medical Association, and the summaries were prepared under its direction.     

Cautious Crows: Neophobia in Torresian Crows (Corvus orru) Compared with Three Other Corvoids in Suburban Australia

Corvids (Family: CORVIDAE) are a clade of some 120 species widespread throughout much of the world that have attracted the interest of researchers due to their impressive cognitive abilities. The group is, however, also generally described as neophobic, a trait that increases the difficulty of undertaking such research. In Australia, Torresian crows (Corvus orru) have, like corvid species worldwide, thrived in urban environments, sharing this habitat with a number of other corvoid (Superfamily: CORVOIDEA) species. While each of these species has successfully colonised urban areas, the extent to which neophobia is present is not known. This study empirically tested the extent to which neophobia is exhibited in wild urban Torresian crows by measuring the delaying effect of a novel object to obtaining food and any changes in neophobic behaviours displayed. This was then compared with the other urban corvoid species that inhabit similar niches. This study confirmed that Torresian crows are significantly wary of a novel objects, displaying more neophobic behaviours and taking longer to attain the food. Crow behaviour provided evidence in support of both the dangerous niche hypothesis and the two‐factor model of neophobia and neophilia. Crows also displayed these behaviours to a significantly greater extent than the three other corvoids studied. However, the individual variation in crow behaviours when exposed to a novel object was extensive. This variation may be attributed to differing behavioural types between individuals, or different experiences with novel objects or humans in the bird's past.     

Bats as prey of diurnal birds: a global perspective

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Virgin male mating advantage in a primitive acoustic insect (Orthoptera: Haglidae)

Male reproductive behavior in the relict flightless haglid, Cyphoderris strepitans,entails the generation of sound signals and the provision of nuptial gifts to mates. These food gifts take two forms: (1) a gelatinous mass (spermatophylax) augmenting the spermatophore and (2) fleshy metathoracic wings adapted to be eaten. The female consumes a portion of the male's underwings during courtship and copulation and the spermatophylax afterward. The incidence of wing-feeding wounds can be used to monitor the mating success of field-caught males. If, when a male mates, he compromises his ability to provide subsequent nutritive gifts, females would benefit by mating with virgin rather than nonvirgin males. To test this, mating success of virgin and nonvirgin males was compared in a field population. Virgins were found to obtain more matings than explained by their numbers relative to nonvirgins in the population. We conclude that, having mated, a male is at a disadvantage, relative to his virgin competitors, in securing further matings.     

The extrinsic 33 kDa polypeptide of the oxygen-evolving complex of photosystem II is a putative calcium-binding protein and is encoded by a multi-gene family in pea

The extrinsic 33 kDa polypeptide of the water-oxidizing complex has been extracted from pea photosystem II particles by washing with alkaline-Tris and purified by ion-exchange chromatography. The N-terminal amino acid sequence has been determined, and specific antisera have been raised in rabbits and used to screen a pea leaf cDNA library in gt11. Determination of the nucleotide sequence of positive clones revealed an essentially full-length cDNA for the 33 kDa polypeptide, the deduced amino acid sequence showing it to code for a mature protein of 248 amino acids with an N-terminal transit peptide of 81 amino acids. The protein showed a high degree of conservation with previously reported sequences for the 33 kDa protein from other species and the sequence contained a putative Ca²⁺-binding site with homology to mammalian intestinal calcium-binding proteins. Northern analysis of total pea RNA indicated a message of approximately 1.4 kb, in good agreement with the size of the cDNA obtained at 1.3 kbp. Southern blots of genomic DNA probed with the labelled cDNA give rise to several bands suggesting that the 33 kDa polypeptide is coded by a multi-gene family.Abbreviations ATZ - anilinothiazolinone - DITC - p-phenylenediisothiocyanate - PTH - phenylthiohydantoin - TFA - trifluoroacetic acid - Tris - tris (hydroxymethyl) aminomethane - bis-Tris - bis (2-hydroxyethyl) imino-tris (hydroxymethyl)-methane - p.f.u. - plaque-forming units     

Characterization of cDNA clones encoding the extrinsic 23 kDa polypeptide of the oxygen-evolving complex of photosystem II in pea

The 23 kDa polypeptide of the oxygen-evolving complex of photosystem II has been extracted from pea photosystem II particles by washing with 1 M NaCl and purified by anion-exchange chromatography. The N-terminal amino acid sequence has been determined and specific antisera have been raised in rabbits and used to screen a pea-leaf cDNA library in gt11. Determination of the nucleotide sequence of two clones provided the nucleotide sequence for the full 23 kDa polypeptide. The deduced amino acid sequence showed it to code for a mature protein of 186 amino acid residues with an N-terminal presequence of 73 amino acid residues showing a high degree of conservation with previously reported 23 kDa sequences from spinach and Chlamydomonas. Southern blots of genomic DNA from pea probed with the labelled cDNA gave rise to only one band suggesting that the protein is encoded by a single gene. Northern blots of RNA extracted from various organs indicated a message of approximately 1.1 kb, in good agreement with the size of the cDNA, in all chlorophyll-containing tissues. Western blots of protein extracted from the same organs indicated that the 23 kDa polypeptide was present in all major organs of the plant except the roots.Abbreviations bis-Tris bis (2-hydroxyethyl) imino-tris (hydroxymethyl)-methane - pfu plaque-forming units     

Using carbon isotopes to track dietary change in modern,historical, and ancient primates

Stable isotope analysis can be used to document dietary changes within the lifetimes of individuals and may prove useful for investigating fallback food consumption in modern, historical, and ancient primates. Feces, hair, and enamel are all suitable materials for such analysis, and each has its own benefits and limitations. Feces provide highly resolved temporal dietary data, but are generally limited to providing dietary information about modern individuals and require labor-intensive sample collection and analysis. Hair provides less well-resolved data, but has the advantage that one or a few hair strands can provide evidence of dietary change over months or years. Hair is also available in museum collections, making it possible to investigate the diets of historical specimens. Enamel provides the poorest temporal resolution of these materials, but is often preserved for millions of years, allowing examination of dietary change in deep time. We briefly discuss the use of carbon isotope data as it pertains to recent thinking about fallback food consumption in ancient hominins and suggest that we may need to rethink the functional significance of the australopith masticatory package. Am J Phys Anthropol 140:661–670, 2009. © 2009 Wiley-Liss, Inc.     

The influence of prior hamstring injury on lengthening muscle tissue mechanics

Hamstring strain injuries often occur near the proximal musculotendon junction (MTJ) of the biceps femoris. Post-injury remodeling can involve scar tissue formation, which may alter contraction mechanics and influence re-injury risk. The purpose of this study was to assess the affect of prior hamstring strain injury on muscle tissue displacements and strains during active lengthening contractions. Eleven healthy and eight subjects with prior biceps femoris injuries were tested. All previously injured subjects had since returned to sport and exhibited evidence of residual scarring along the proximal aponeurosis. Subjects performed cyclic knee flexion–extension on an MRI-compatible device using elastic and inertial loads, which induced active shortening and lengthening contractions, respectively. CINE phase-contrast imaging was used to measure tissue velocities within the biceps femoris during these tasks. Numerical integration of the velocity information was used to estimate two-dimensional tissue displacement and strain fields during muscle lengthening. The largest tissue motion was observed along the distal MTJ, with the active lengthening muscle exhibiting significantly greater and more homogeneous tissue displacements. First principal strain magnitudes were largest along the proximal MTJ for both loading conditions. The previously injured subjects exhibited less tissue motion and significantly greater strains near the proximal MTJ. We conclude that localized regions of high tissue strains during active lengthening contractions may predispose the proximal biceps femoris to injury. Furthermore, post-injury remodeling may alter the in-series stiffness seen by muscle tissue and contribute to the relatively larger localized tissue strains near the proximal MTJ, as was observed in this study.