The synonymy and distribution of the crenulata-and psittacina-groups of Atractomorpha Saussure 1862 (Orthoptera: Acridoidea: Pyrgomorphidae)

A full bibliography and the known distributional range, illustrated by maps, are given for Atractomorpha himalayica Bolivar, A. crenulata (Fabricius), A. rhodoptera Karsch, A. angusta Karsch, A. sinensis Bolivar, A. lata (Motschoulsky) (= A. bedeli Bolivar), A. psittacina (Haan) and A. burri Bolivar. A. nipponica Steinmann is newly synonymized with the last. This completes the work for the genus, the aberrans- and crenaticeps-gcoups , and A. acutipennis (Guerin) of the creniWafa-group having been previously considered.     

Growth-interruption surfaces within chaetetid skeletons: Records of physical disturbance and depositional dynamics

Records of growth interruptions within spongiomorph and colonial skeletons provide a unique window into the disturbance dynamics of ancient shallow marine benthic environments at ecological time scales. The utility of growth-interruption surfaces for inferring the frequency of physical disturbance and the relative rate of sediment accumulation is illustrated by chaetetid skeletons from several Middle Pennsylvanian (Desmoinesian) sequences of southeastern Kansas. Five different growth-interruption surfaces are recognized within these calcareous demos-ponges: (1) breaks in growth with apparent continuity of tubules across the surface, (2) surfaces of rejuvenation or recolonization with reorientation of tubules, (3) sediment-filled tubules or trapped sediment partings, (4) encrusted surfaces, and (5) biocorroded or bored surfaces. A single skeleton may contain several types of surfaces, and individual surfaces may change in character across the skeleton. The type and spacing of growth-interruption surfaces vary with chaetetid growth form. Together with growth form, these surfaces provide a basis for paleoen-vironmental interpretation.     

Prostaglandin Biosynthesis from Endogenous Precursors in Rabbit Kidney

THIS report describes the biosynthesis of the naturally occurring renal prostaglandins E₂ (PGE₂) and F_2α (PGF_2α)^1,2 by homogenates and slices of rabbit renal medulla, from endogenous precursors. I have confirmed that rabbit renal cortex contains little prostaglandin and cannot synthesize them from endogenous lipids³. Hamberg has reported that arachidonic acid, which is converted to PGE₂ and PGF_2α by enzymes present in ram seminal vesicles⁴, can be efficiently converted to PGE₂ and PGF_2α by homogenates of rabbit renal medulla³. I have now confirmed that arachidonic acid, added to such medullary homogenates, can increase the quantities of prostaglandins synthesized. There was no evidence that the major prostaglandin biosynthesized, PGE2, was further metabolized to inactive products.     

Geographical patterns of evolution in Neotropical Lepidoptera: differentiation of the species of Melinaea and Mechanitis (Nymphalidae,Ithomiinae)*

Abstract Biosystematic analysis incorporating abundant new field data from many parts of the Neotropics has led to an ordered revision of the mimetic ithomiine genera Melinaea and Mechanitis. The various polytypic species of these general probably served as prime movers for the differentiation of other mimetic butterflies in Quaternary forest refuges. The revisions are presented in the form of supplements to the works of Richard M. Fox on these genera, with analyses based on his divisions. Seven species (or monophyletic species-groups) and sixty-three well-differentiated geographic subspecies (six of these described here for the first time) are recognized in Melinaea. Specimens are illustrated which demonstrate intergradation between refuge-derived subspecies. Five species and fifty-two differentiated subspecies are recognized in Mechanitis, whose members are more abundant and gregarious, more plastic, and apparently more vagile than those of Melinaea, resulting in fewer clear-cut mimetic associations, more extensive blurring of differentiation patterns, and apparently fewer incipient biological species in this genus than in Melinaea.     

A Comparative Study of Cotyledons as Assimilatory Organs

Cotyledons of 11 species were studied at a number of stagesof germination. The hypogeal pea and runner bean cotyledonsdid not expand, lost weight, and survived for a relatively shorttime only. They also produced little chlorophyll on exposureto light, possessed no stomata, and had a very low capacityfor ¹⁴CO₂ fixation. The epigeal french bean had cotyledons thatwere basically of the hypogeal type. Although both white andblue lupin cotyledons showed a progressive weight loss, theyunderwent limited expansion and were more persistent than eitherpea or bean. They also produced considerable amounts of chlorophyll,had stomata on both upper and lower surfaces, and fixed restrictedquantities of ¹⁴CO₂. The cotyledons of the other epigeal speciesstudied showed varying degrees of expansion, up to almost fifty-foldin cucumber, and generally maintained or increased in totaldry weight for at least a restricted period. Stomata occurredon both upper and lower surfaces, extensive chlorophyll productiontook place, and ¹⁴CO₂ fixation values were high. Expansion was determined by increase in cell size, and not incell number except in the case of cucumber where both factorswere involved. In species where cotyledon cells were large initiallylittle or no expansion occurred, whereas initial cell size wassmall in cotyledons which expanded to a large extent. Epigeal cotyledons with a high expansion factor possessed othercharacteristics which made them adapted for photosynthesis,whereas epigeal species with lower cotyledon expansion togetherwith hypogeal species were less well adapted. This was not unexpectedin the case of pea and runner bean, but led to the conclusionthat french bean cotyledons are ‘accidentally epigeal’in that they showed virtually no adaptation to an aerial existence.The different capacities of the cotyledons studied suggeststhat they have differing roles in the control of seedling growth.     

Assembly of the Paraflagellar Rod and the Flagellum Attachment Zone Complex During the Trypanosoma brucei Cell Cycle

Trypanosomes possess a single flagellum that is attached to their cell body via the flagellum attachment zone (FAZ). The FAZ is composed of two structures: a cytoplasmic filament complex and four microtubules situated next to it. There is a complex transmembrane crosslinking of this FAZ to the paraflagellar rod (PFR) and axoneme within the flagellum. We have partially purified the FAZ complex and have produced monoclonal antibodies both against the FAZ and the paraflagellar rod. The two antibodies against the FAZ (L3B2 and L6B3) recognise the cytoplasmic filament in immunofluorescence and in immunoelectron microscopy. On western blot, they detect a doublet of high molecular weight (M(r) 200,000). Two anti-PFR antibodies (L13D6 and L8C4) recognise the paraflagellar rod in immunofluorescence, but show a difference on Western blot: L13D6 recognises both major PFR proteins, whereas L8C4 is specific for only one of them. Using these new antibodies we have shown that although the growth of both cytoplasmic FAZ filament and external PFR are related, their growth initiates at different time points during the cell cycle and the two structures elongate at distinct rates.     

Comparison of Endocrine Response to Stress Between Captive-Raised and Wild-Caught Bighorn Sheep

ABSTRACT Stress hormones in Rocky Mountain bighorn sheep (Ovis canadensis canadensis), produced in response to environmental changes, road development, or high population density, may impact their immune systems to a threshold level that predisposes them to periodic, large-scale mortality. We compared the stress response to a novel environmental situation and repeated handling between bighorn sheep born and raised in captivity (CR) and bighorn sheep born in the wild (WC) and brought into captivity. We measured plasma epinephrine, norepinephrine, cortisol, and fecal glucocorticoid metabolites (FGM). Three weeks after each group's arrival we used a one-time drop-net event to elicit an acute stress response, and we collected blood samples from each sheep over 35 minutes, as well as one fecal sample. We collected blood and fecal samples from both groups on 7 other occasions over the subsequent 6 months. We also collected fecal samples from the pen at approximately 24-hour intervals for 3 days following every handling event to monitor the stress response to handling. We found that CR sheep had a stronger autonomic nervous system response than WC sheep, as measured by epinephrine and norepinephrine levels, but we found a very similar hypothalamic-pituitary–adrenal axis (HPA) response, measured by cortisol levels, to the acute stress event of a drop-net restraint. We also found that once the WC sheep had acclimated, as indicated by the return to the initial baseline FGM levels within 12 weeks, the CR and WC groups' HPA responses to sampling events were not significantly different from one another. Fecal samples can provide a noninvasive mechanism for managers to monitor baseline FGM for a given herd. Using long-term monitoring of FGM rather than values from a single point in time may allow managers to correlate these levels to outside influences on the herd and better understand the impacts of management changes, population density, or increased human developments on the health of the sheep population.     

Eimeria tenella: Parasite-Specific Incorporation of 3H-Uracil as a Quantitative Measure of Intracellular Development1

ABSTRACT. An assay has been developed using parasite-specific incorporation of ³H-uracil to assess the intracellular growth of Eimeria tenella in vitro. As shown by both scintillation counts and autoradiography, ³H-uracil was incorporated specifically into intracellular parasites from the onset of infection and continued throughout development of the first generation schizonts. Mature schizonts and first generation merozoites did not continue to incorporate additional ³H-uracil, indicating that RNA synthesis had halted in these stages. Based on these findings, a semi-automated microscale uracil incorporation assay was developed to determine parasite viability. This method should be useful for biochemical studies with intracellular parasites and for screening compounds for anticoccidial activity. The ease, rapidity, and quantitative nature of this assay contrasts favorably with standard morphometric approaches of determining parasite development. In addition, parallel studies using host cell incorporation of ³H-uridine have been introduced as a method of determining whether antiparasitic activity is direct or indirect in relation to effects on the host cell.