Timed surveys and transect walks as comparable methods for monitoring butterflies in small plots

Butterflies are widely used in biodiversity surveys, and several methods of relative abundance counts have been developed. The most frequently used linear transects are praised for a good replicability, but recently have been criticised for poor species detecting ability, especially for poorly visible or extremely sedentary species. As an alternative, timed surveys, based on zigzagging study sites and flexibly checking transient butterfly resources, have been proposed by some authors. We tested the utility of the two methods while studying the effect of restoration practices on butterfly assemblages in limestone quarries in the Czech Republic. Numbers of species and individuals detected per 10 min transect walk were compared with numbers of species and individuals detected during 10 min timed survey. Mobile and imperceptible species were compared in separate analyses as a measure of detection efficiency. More species and individuals per visit were recorded by timed surveys. No difference in detectability of mobile and imperceptible species between both methods used was observed. Whereas linear transects will probably remain the method of choice for long-term monitoring programs employing armies of recorders, timed surveys appear more appropriate for studies in which it is important to obtain the most comprehensive check-list of species occurring at study sites, which is often the case in conservation inventories in species rich regions with limited number of experienced researchers.     

Protein kinase C activity and isoform expression during early postnatal development of rat myocardium

Total protein kinase C (PKC) activity, its isoform expression, and concentration and fatty acid (FA) composition of diacylglycerol (DAG) were determined in the left ventricular myocardium of the rat during early postnatal development (d 2, 3, 5, 7, and 10). PKC activity measured by the incorporation of ³²P into histone IIIS decreased between d 2 and 10 in the homogenate as well as in cytosolic, membrane (100,000g), and nuclear-cytoskeletal-myofilament fractions (1000g). Likewise, the expression of PKC isoforms (α, δ, and ε) determined by immunoblotting generally declined during the period analyzed, although with a variable pattern. In the membrane and nuclear cytoskeletal myofilament fractions, PKCδ and PKCε expression decreased markedly by d 3, returning to or close to the d 2 level immediately on d 5. PKCα expression in the membrane fraction remained almost unchanged by d 7, declining thereafter. PKCδ and PKCε were associated predominantly with particulate fractions, whereas PKCα was more abundant in the cytosolic fraction. DAG concentration exhibited a significant decline by d 5, consistent with the decrease in maximal PKC activity. The unsaturation index of FA in DAG tended to decrease on d 3 owing to the lowered proportion of all polyunsaturated FA of n−6 and n−3 series. These results demonstrate that the developmental decrease in PKC activity and expression in the rat myocardium is not linear and that subcellular localization of the enzyme exhibits isoform-specific day-by-day changes during the early postnatal period. These changes are compatible with the view that PKC signaling may be involved in the control of a rapid switch of myocardial growth pattern during the first week of life.     

Long-term agonist stimulation of IP prostanoid receptor depletes the cognate G(s)alpha protein in membrane domains but does not change the receptor level

Iloprost (IP) stimulation (1 microM, 2 h) of Flag-epitope-tagged human IP prostanoid receptor (FhIPR) expressed in HEK293 cells resulted in specific decrease of endogenous G(s)alpha protein in detergent-insensitive, caveolin-enriched, membrane domains (DIMs). Receptor protein FhIPR, caveolin, G(i)alpha and GPI-linked, domain markers CD55 and CD59 were unchanged. The same result was obtained in HEK293 cells expressing FhIPR-G(s)alpha fusion protein. The endogenous G(s)alpha decreased, but the level of Flag-hIPR-G(s)alpha protein did not change. The specific depletion of domain-bound pool of G(s)alpha as consequence of iloprost stimulation was also demonstrated in membrane domains prepared according to alkaline treatment plus sonication protocol (detergent-free procedure of Song et al.). Our data further indicated that in control, quiescent cells only a very small amount of IP prostanoid receptor was present in DIMs together with large amount of its cognate G(s)alpha protein. Expressed in quantitative terms, DIMs contained 30-40% of the total cellular amount of G proteins whereas the content of IP prostanoid receptors was 1-3%. The dominant portion (>95%) of FhIPR as well as FhIPR-G(s)alpha was localised in high-density area of the gradient containing detergent-solubilised proteins. FhIPR and FhIPR-G(s)alpha distribution was similar to that of transmembrane plasma membrane (PM) markers (CD147, MHCI, CD29, Tapa1, the alpha subunit of Na,K-ATPase, transmembrane form of CD58 and CD44). All these proteins are known to be fully solubilised by detergent and thus unable to float in density gradient. Our data indicate that (i) long-term agonist stimulation of IP prostanoid receptor is associated with preferential decrease of its cognate G protein G(s)alpha from membrane domains; receptor level is unchanged. (ii) Very small fraction (1-3%) of total cellular amount of receptors is recovered in DIMs together with roughly 40% of G proteins. These data suggest a "supra-stoichiometric" arrangement of G proteins and corresponding receptors in DIMs.     

Comparative aspects of cold acclimation and nonshivering thermogenesis in homeotherms

In some small animals (rat, guinea,pig) adaptation to cold entails an increased ability to produce heat through nonshivering thermogenesis. This is closely associated with the calorigenic action of noradrenaline (NA), In bigger animals (rabbit) the magnitude of nonshivering thermogenesis governed by NA is smaller and these animals rely mostly on adaptation by means of increased insulation. In some other species (white mouse, hedgehog, dog, young fowl)the role of NA in cold acclimation is either not clear or dubious. The last group of homeotherms involves species which do not show either nonshivering thermogenesis or increased insulation after cold adaptation although the resistance to cold has been found to be increased (pigeon, chickens, miniature swine, new born pig). An entirely new mechanism of cold adaptation must be anticipated in these species.

---

Zusammenfassung In einigen kleineren Tierarten (Ratte, Meerschweinchen) schliesst die Anpassung an Kälte eine erhöhte Fähigkeit zur Wärmebildung ohne Muskelzittern ein. Dieser Beitrag zur Wärmebildung ist zusätzlich zu dem durch Muskelzittern und eng mit der kalorigenen Wirkung von Noradrenalin (NA) verbunden. Grössere Tiere passen sich an Kälte vorwiegend durch Verbesserung der Isolation an (Kaninchen). Der Anteil der durch NA gesteuerten Thermogenese ist gering. Bei anderen Tieren (Maus, Igel, Hund, junges Geflügel) ist die Rolle des NA entweder noch nicht abgeklärt oder zweifelhaft. Schliesslich gibt es Tiere (Taube, Huhn, junge Schweine), die bei Kälteakklimatisation weder eine Verbesserung der Isolation noch zitterfreie Thermogenese aufweisen. Bei diesen Tierarten muss ein völlig neuer Mechanismus der Kälteanpassung angenommen werden.

---

Resume Pour quelques espèces de petits animaux (rats, cobaye), l'adaptation au froid englobe la possibilité accrue de production de chaleur sans tremblement musculaire. Cette contribution à la production de chaleur se greffe à celle provenant du tremblement musculaire et est étroitement liée à l'effet calorigène de la noradrénaline (NA). De plus gros animaux s'adaptent au froid surtout par une amélioration de l'isolation (lapin). La part de chaleur due à l'effet de la NA y est faible. Pour d'autres espèces (souris, hérisson, chien, jeune volaille), le rôle joué par la NA est ou peu clair ou douteux. Enfin, certains animaux (pigeons, poules,porcelets) ne présentent ni amélioration de l'isolation ni production de chaleur par tremblement musculaire au cours de l'acclimatation au froid. Dans ces cas-là, il faut admettre un mécanisme entièrement nouveau d'adaptation au froid.

---

---

Presented during the Fifth International Biometeorological Congress, 1–7 September 1969, Montreux, Switzerland.     

Aphid-ant-parasite relationship in Iraq

Lists of aphids and associated ants and parasites recognized in Iraq in 1968 are given. On this base, some factors affecting the relationship are reviewed and documented. The attendance-range of ants and relation of parasites were found to be influenced by distribution, microhabitat, honeydew, shape of aphid colony and host range of parasites. Aphids, attending-ants and parasites associated withQuercus sp. are used as a demonstration.

---

Résumé L'auteur donne une liste d'Aphides, de fourmis associées et de parasites étudiés en Iraq en 1968; il fait une revue critique des facteurs affectant leurs relations. L'étendue des soins donnés par les fourmis et les relations avec des parasites se révèlent influencées par la distribution géographique, le microhabitat, la production de miellat, la forme des colonies d'aphides et la spécificité des parasites. Les Aphides, fourmis soigneuses et les parasites associés au Quercus sp. sont utilisés comme exemples.

     

Leishmania chitinase facilitates colonization of sand fly vectors and enhances transmission to mice

Chitinases of trypanosomatid parasites have been proposed to fulfil various roles in their blood-feeding arthropod vectors but so far none have been directly tested using a molecular approach. We characterized the ability of Leishmania mexicana episomally transfected with LmexCht1 (the L. mexicana chitinase gene) to survive and grow within the permissive sand fly vector, Lutzomyia longipalpis. Compared with control plasmid transfectants, the overexpression of chitinase was found to increase the average number of parasites per sand fly and accelerate the escape of parasites from the peritrophic matrix-enclosed blood meal as revealed by earlier arrival at the stomodeal valve. Such flies also exhibited increased damage to the structure of the stomodeal valve, which may facilitate transmission by regurgitation. When exposed individually to BALB/c mice, those flies with chitinase-overexpressing parasites spent on average 2.4-2.5 times longer in contact with their host during feeding, compared with flies with control infections. Furthermore, the lesions that resulted from these single fly bite infections were both significantly larger and with higher final parasite burdens than controls. These data show that chitinase is a multifunctional virulence factor for L. mexicana which assists its survival in Lu. longipalpis. Specifically, this enzyme enables the parasites to colonize the anterior midgut of the sand fly more quickly, modify the sand fly stomodeal valve and affect its blood feeding, all of which combine to enhance transmission.     

The protective effect against Leishmania infection conferred by sand fly bites is limited to short-term exposure

Under laboratory conditions, hosts exposed twice to sand fly saliva are protected against severe leishmaniasis. However, people in endemic areas are exposed to the vector over a long term and may experience sand fly-free periods. Therefore, we exposed mice long- or short-term to Phlebotomus duboscqi bites, followed by Leishmania major infection either immediately or after a sand fly-free period. We showed that protection against leishmaniasis is limited to short-term exposure to sand flies immediately before infection. Our results may explain the persistence of leishmaniasis in endemic areas and should be taken into account when designing anti-Leishmania vaccines based on sand fly saliva.     

Glycogen,poly(3-hydroxybutyrate) and pigment accumulation in three Synechocystis strains when exposed to a stepwise increasing salt stress

Journal of Applied Phycology - The cyanobacterial genus Synechocystis is of particular interest to science and industry because of its efficient phototrophic metabolism, its accumulation of the...