436 resultados para dung beetle
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Tree hollows are keystone structures for saproxylic fauna and host numerous endangered species. However, not all tree hollows are equal. Many variables including physical, biotic and chemical ones, can characterise a tree hollow, however, the information that these could provide about the saproxylic diversity they harbour has been poorly explored. We studied the beetle assemblages of 111 Quercus species tree hollows in four protected areas of the Iberian Peninsula. Three physical variables related to tree hollow structure, and two biotic ones (presence of Cetoniidae and Cerambyx species recognised as ecosystem engineers) were measured in each hollow to explore their relative effect on beetle assemblages. Moreover, we analysed the chemical composition of the wood mould in 34 of the hollows, in order to relate beetle diversity with hollow quality. All the environmental variables analysed (physical and biological) showed a significant influence on saproxylic beetle assemblages that varied depending on the species. Furthermore, the presence of ecosystem engineers affected both physical and chemical features. Although wood mould volume, and both biotic variables could act as beetle diversity surrogate, we enhance the presence of Cetoniidae and Cerambyx activity (both easily observable in the field) as indicator variables, even more if both co-occur as each affect to different assemblages. Finally, assimilable carbon and phosphorous contents could act as indicator for past and present beetle activity inside the cavity that could become a useful tool in functional diversity studies. However, an extension of this work to other taxonomic groups would be desirable.
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Traditionally, ice-binding proteins (IBPs), also known as antifreeze proteins (AFPs), have been defined by two universal activities: ice recrystallization inhibition and thermal hysteresis. However, there remains the possibility IBPs have other complementary functions given the diversity found within this protein group. This thesis explores some of these in both natural and applied settings, in the hopes of furthering our understanding of this remarkable group of proteins. Plant IBPs could function as part of a defensive strategy against ice nucleators produced by certain pathogens. To assess this hypothesis, recombinant IBPs from perennial ryegrass and purple false brome were combined with the ice nucleation protein (INP) from the plant pathogen, Pseudomonas syringae. Strikingly, the plant proteins depressed the freezing point of the bacterial INP, while a fish AFP could not, nor did the INPs have any effect on IBP activity. Thus, the interaction between these two different proteins suggests a role in plant defensive strategies against pathogenic bacteria as another IBP function. In addition, the potential use of hyperactive insect IBPs in organ preservation was investigated. Current kidney preservation techniques involve storing the organ at 4 °C for a maximum of 24 h prior to transplantation. Extending this “safe” time would have profound effects on renal transplants, however, ischemic injury is prevalent when storage periods are prolonged. Experiments described here allowed subzero preservation for 72 h with the addition of a beetle IBP to CryoStasis® solution. Kidneys stored using the traditional technique for 24 h and the method developed here for 72 h showed similar levels of biomarker enzymes, underscoring the potential utility of insect IBPs for future transplant purposes. Finally, IBP function in the freeze-tolerant gall fly, Eurosta solidaginis, was examined. Larvae representing the mid-autumn stage displayed ice-binding activity, suggesting an IBP is being expressed, possibly as a protective measure against freezing damage when fall temperatures can unpredictably drop. IBP activity was also observed in the larvae’s host plant, Solidago spp. Mass spectrometry analysis of ice-affinity purified plant extracts provided three candidate pathogenesis-related proteins that could be responsible for the detected activity, further demonstrating additional functions of IBPs.
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This chapter provides a review of proxy data from a variety of natural archives sampled in the Wollaston Forland region, central Northeast Greenland. The data are used to describe long-term environmental and climatic changes. The focus is on reconstructing the Holocene conditions particularly in the Zackenberg area. In addition, this chapter provides an overview of the archaeological evidence for prehistoric occupation of the region. The Zackenberg area has been covered by the Greenland Ice Sheet several times during the Quaternary. At the Last Glacial Maximum (LGM, about 22,000 years BP), temperatures were much lower than at present, and only very hardy organisms may have survived in the region, even if ice-free areas existed. Marked warming at around 11,700 years BP led to ice recession, and the Zackenberg area was deglaciated in the early Holocene, prior to 10,100 years BP. Rapid early Holocene land emergence was replaced by a slight transgression in the late Holocene. During the Holocene, summer solar insolation decreased in the north. Following deglaciation of the region, summer temperatures probably peaked in the early to mid-Holocene, as indicated by the occurrence of a southern beetle species. However, the timing for the onset of the Holocene thermal maximum is rather poorly constrained because of delayed immigration of key plant species. During the thermal maximum, the mean July temperature was at least 2-3°C higher than at present. Evidence for declining summer temperatures is seen at around 5500, 4500 and 3500 years BP. The cooling culminated during the Little Ice Age that peaked about 100-200 years ago. The first plants that immigrated to the region were herbs and mosses. The first dwarf shrubs arrived in Northeast Greenland prior to 10,400 years BP, and dwarf birch arrived around 8800 years BP. The first people arrived about 4500 years BP, but the region was depopulated several times before the last people disappeared some time after 1823 AD, perhaps as a consequence of poor hunting conditions during the peak of the Little Ice Age.
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National Highway Traffic Safety Administration, Washington, D.C.
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National Highway Traffic Safety Administration, Washington, D.C.
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National Highway Traffic Safety Administration, Washington, D.C.
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Ascobolus castaneus Teng, determined by S.C. Teng
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Typewritten.
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10 of the plates are preceded by leaf with descriptive letterpress.
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Issued Nov. 1974.
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Top Row: Alexis Adamjee, Jennifer Ahlquist, Crista Andress, Dawn Arringdale, Freda Ayensu, Genevieve Balangero, Maureen Berlucchi, Amanda Bevier, Nina Bibicoff, Rachel Black, Denise Black, Jackie Braun, Kristen Bryant, Betty Burgner, Julie Butchart, Nicholas Cameron, Jessica Carver, Christine Cha, Kelly Clement
Row 2: Lauren Cochran, Kathleen Connell, Amanada Cooperwasser, Lindsay Cousino, Lindsey Evans, Stephen Kilijanczyk, Kathryn Evans, Kathryn Bucrek, Ida Elise Broadwater, Renee Havey, Sharon Warner, Katie Darnell, Katrina DeWitt, Kolleen Kowalske, Keather Rechtweg, Kristen Cowan, Alison Damioli, Dinah Denton, Melinda Dobie
Row 3: Rosemarie Donnelly, Kelly Doyle, Deanna Dusseau, Jacqueline Elegant, Ashley Faulk, Kristin Ferszt, Christine Catalan, Sarah Borgstadt-Smith, Paul Holtz, Tracy Jakubiec, Chemari Justice, Patricia Oppenheim, Kelly Fleming, Melissa Foster, Emily French, Tracy Gallo, Kathie Garrett, Jacqueline Garry
Row 4: Monique Gennari, Megan Gerlinger, Deborah Glazer, Terah Griggs, Edward Grosser, Kristy Haigh, Amanda Halbert, Jennifer Hammer, Emily Harris, Erin Harris, Elizabeth Hassenrik, Elizabeth Heinbeck
Row 5: Brianna Hirsch, Jessica Hoffman, Heather Hoffner, Bridget Holtz, Melissa Housefield, Sarah Hudson, Kathy Huffnagle, Hilary Hunt, Ashley Jannesen, Lauren Jarvis, Sarah Jarvis, Younhee Jee
Row 6: Ruth Jensen, Janet Wilson Johnston, Brandi Josephs, Amy Kangwankij, Julie Kramb, Dianna Krankurs, Allan Kucab, Kimberly Lai, Sarah Layher, Erin Layher, Dung Le, Hedy Leiter
Row 7: Lauren Loftus, Michael Long, Caroline Loukotka, Shoshana Love, Norma Martinez, Kristen McElreath, Lindsi McErlean, Renee McGlone, Lynne McIntosh, Ian McLelland, Ashley Mester, Anika Meyers
Row 8: Elizabeth Miles, Sarah Miller, Juliana Moore, Nicole Nastanski, Sarah Neighbours, Emily Newman, Judith Lynch-Sauer, Patricia Coleman-Burns, Judith Wismont, Kathleen Potempa, Carol Loveland-Cherry, Carolyn Sampselle, Joanne Pohl, Katie Pace, Bethany Panyard, sejal Patel, Chelsea Patnoude, Amy Jo Perry, Joseph Piotrowski
Row 9: Kate Pittel, Natalie Podolsky, Jessica Pollman, Nicole Pratt, Laura Ready, Amanda Retzbach, Katie Richards, Nicole Rico, April Robertson, Meighan Robinson, Stephanie Robinson, Talia Roesner, Autumn Romanowski, Anne Sage, Sally Scharg, Melissa Schultz, Renee Shelton, Natalie Sherry
Row 10: Rebecca Siereveld, Karen Simon, Emily Sosnowski, Elissa Stier, Darcy Stoll, Nicole Sukich, Erin Sykes-Miller, Tami Szuba, John Tallman, Michelle Taylor, Ashley Thelen, Gina Thomas, Rachel Tovian, Yuanyuan Wan, Nicole Young
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"The preliminary American second edition of A.L.A. catalog rules, on Part I of which the present volume is based, was prepared by: American Library Association, Catalog Code Revision Committee." The 1st ed., published in 1908, has title: Catalog rules, author and title entries.
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Cover title.
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Elevated jasmonic acid (JA) concentrations in response to herbivory can induce wounded plants to produce defences against herbivores. In laboratory and field experiments we compared the effects of exogenous JA treatment to two closely related cabbage species on the host-searching and oviposition preference of the diamondback moth (DBM), Plutella xylostella. JA-treated Chinese cabbage (Brassica campestris) was less attractive than untreated Chinese cabbage to ovipositing DBM, while JA-treatment of common cabbage (B. oleracea) made plants more attractive than untreated controls for oviposition by this insect. Similar effects were observed when plants of the two species were damaged by DBM larvae. In the absence of insect-feeding, or JA application, Chinese cabbage is much more attractive to DBM than common cabbage. Inducible resistance therefore appears to occur in a more susceptible plant and induced susceptibility appears to occur in a more resistant plant, suggesting a possible balance mechanism between constitutive and inducible defences to a specialist herbivore.
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Offspring size can have pervasive effects throughout an organism's life history. Mothers can make either a few large or many small offspring, and the balance between these extremes is determined by the relationship between offspring size and performance. This relationship in turn is thought to be determined by the offspring's environment. Recently, it has become clear that events in one life-history stage can strongly affect performance in another. Given these strong carryover effects, we asked whether events in the larval phase can change the relationship between offspring size and performance in the adult phase. We manipulated the length of the larval period in the bryozoan Bugula neritina and then examined the relationship between offspring size and various parameters of adult performance under field conditions. We found that despite the adult stage being outplanted into identical conditions, different offspring sizes were predicted to be optimal, depending on the experience of those adults as larvae. This work highlights the fact that the strong phenotypic links between life-history stages may result in optimal offspring size being highly unpredictable for organisms with complex life cycles.