173 research outputs found
Population Growth of the Pitcher Plant, Sarracenia Purprea L., at Cranberry Bog, Licking County, Ohio
Author Institution: Department of Botany, University of IllinoisA population of the pitcher plant, Sarracenia purpurea L., at Cranberry Bog Nature Preserve, Licking County, Ohio, was founded by a single individual transplanted to the bog in 1912. From an observation of the population in 1921, the intrinsic rate of increase for this population was estimated to be between .0016 and .0023 per day. A recent survey of the present size of the population revealed approximately 157,000 pitcher plants. These observations suggest that the population has not only reached the carrying capacity of Cranberry Bog, but that it did so as early as 1942. Comparisons between the intrinsic rate of increase for S. purpurea and the few other plant species that have been studied suggest that pitcher plants have a relatively slow rate of population increase for an herbaceous species
Pyoderma Gangrenosum Associated with Sclerosing Cholangitis, Type 1 Diabetes Mellitus and Ulcerative Colitis
We describe the case of a 22-year-old black female with type 1 diabetes mellitus diagnosed when she was 12 years old. She first presented (March 1994) with pustules and ulcerations on the upper and lower limbs, trunk and scalp at the age 17. The diagnosis of pyoderma gangrenosum was made. Since presentation, changes in liver function were detected and subsequent study led to the diagnosis of sclerosing cholangitis. The diagnosis of ulcerative colitis was made after colonoscopy. Partial response was obtained with minocycline and clofazimine, but treatment with 5-aminosalicylic acid achieved no improvement of the ulcerations. Liver transplantation, followed by immunosuppressive therapy led to complete regression of the cutaneous lesions
Genetic and maternal effects on tail spine and body length in the invasive spiny water flea (Bythotrephes longimanus)
Interest in the evolution of invasive species has grown in recent years, yet few studies have investigated sources of variation in invasive species traits experiencing natural selection. The spiny water flea, Bythotrephes longimanus, is an invasive zooplankton in the Great Lakes that exhibits seasonal changes in tail spine and body length consistent with natural selection. Evolution of Bythotrephes traits, however, depends on the presence and magnitude of quantitative genetic variation, which could change within or across years. Clonal analysis of wild-captured Bythotrephes indicated that variance components for distal spine length were variable among but not within years. Spine length was always heritable but was not always influenced by maternal effects. In contrast, variance components for body length varied both within and among years, but likewise body length was always heritable and not always influenced by maternal effects. Results indicate that important Bythotrephes traits have heritable variation comparable to native species and other invasive species that would enable an evolutionary response to natural selection. This evolutionary capacity could contribute to the widespread success and dramatic effects of Bythotrephes invasion in systems with diverse biotic and abiotic conditions
Heritability of seed weight in Maritime pine, a relevant trait in the transmission of environmental maternal effects
Quantitative seed provisioning is an important life-history trait with strong effects on offspring phenotype and fitness. As for any other trait, heritability estimates are vital for understanding its evolutionary dynamics. However, being a trait in between two generations, estimating additive genetic variation of seed provisioning requires complex quantitative genetic approaches for distinguishing between true genetic and environmental maternal effects. Here, using Maritime pine as a long-lived plant model, we quantified additive genetic variation of cone and seed weight (SW) mean and SW within-individual variation. We used a powerful approach combining both half-sib analysis and parent-offspring regression using several common garden tests established in contrasting environments to separate G, E and G x E effects. Both cone weight and SW mean showed significant genetic variation but were also influenced by the maternal environment. Most of the large variation in SW mean was attributable to additive genetic effects (h(2) = 0.55-0.74). SW showed no apparent G x E interaction, particularly when accounting for cone weight covariation, suggesting that the maternal genotypes actively control the SW mean irrespective of the amount of resources allocated to cones. Within-individual variation in SW was low (12%) relative to between-individual variation (88%), and showed no genetic variation but was largely affected by the maternal environment, with greater variation in the less favourable sites for pine growth. In summary, results were very consistent between the parental and the offspring common garden tests, and clearly indicated heritable genetic variation for SW mean but not for within-individual variation in SW.This study was financed by the Spanish National Research Grants RTA2007-100 and AGL2012-40151 (FENOPIN), both co-financed by EU-FEDER. The progeny trials and the clonal seed orchards are part of the experimental set up of the Maritime pine breeding programme developed by the Centro de Investigacion Forestal de Lourizan, Xunta de Galicia.Spanish National Research Grant RTA2007-100Spanish National Research Grant AGL2012-40151 (FENOPIN)EU-FEDERPeer reviewe
Increased Fitness of Rice Plants to Abiotic Stress Via Habitat Adapted Symbiosis: A Strategy for Mitigating Impacts of Climate Change
Climate change and catastrophic events have contributed to rice shortages in several regions due to decreased water availability and soil salinization. Although not adapted to salt or drought stress, two commercial rice varieties achieved tolerance to these stresses by colonizing them with Class 2 fungal endophytes isolated from plants growing across moisture and salinity gradients
Pyoderma gangrenosum – a review
Pyoderma gangrenosum (PG) is a rare noninfectious neutrophilic dermatosis. Clinically it starts with sterile pustules that rapidly progress and turn into painful ulcers of variable depth and size with undermined violaceous borders. The legs are most commonly affected but other parts of the skin and mucous membranes may also be involved. Course can be mild or malignant, chronic or relapsing with remarkable morbidity. In many cases PG is associated with an underlying disease, most commonly inflammatory bowel disease, rheumatic or haematological disease and malignancy. Diagnosis of PG is based on history of an underlying disease, typical clinical presentation, histopathology, and exclusion of other diseases that would lead to a similar appearance. The peak of incidence occurs between the ages of 20 to 50 years with women being more often affected than men. Aetiology has not been clearly determined yet. The treatment of PG is a challenge. Randomized, double-blinded prospective multicenter trials for PG are not available. The best documented treatments are systemic corticosteroids and ciclosporin A. Combinations of steroids with cytotoxic drugs are used in resistant cases. The combination of steroids with sulfa drugs or immunosuppressants has been used as steroid-sparing modalities. Anti-tumor necrosis alpha therapy in Crohn's disease showed a rapid response of PG. Skin transplants and the application of bioengineered skin is useful in selected cases as a complement to the immunosuppressive treatment. Topical therapy with modern wound dressings is useful to minimize pain and the risk of secondary infections. Despite recent advances in therapy, the prognosis of PG remains unpredictable
Phylogeny and Biogeography of the Carnivorous Plant Family Sarraceniaceae
The carnivorous plant family Sarraceniaceae comprises three genera of wetland-inhabiting pitcher plants: Darlingtonia in the northwestern United States, Sarracenia in eastern North America, and Heliamphora in northern South America. Hypotheses concerning the biogeographic history leading to this unusual disjunct distribution are controversial, in part because genus- and species-level phylogenies have not been clearly resolved. Here, we present a robust, species-rich phylogeny of Sarraceniaceae based on seven mitochondrial, nuclear, and plastid loci, which we use to illuminate this family's phylogenetic and biogeographic history. The family and genera are monophyletic: Darlingtonia is sister to a clade consisting of Heliamphora+Sarracenia. Within Sarracenia, two clades were strongly supported: one consisting of S. purpurea, its subspecies, and S. rosea; the other consisting of nine species endemic to the southeastern United States. Divergence time estimates revealed that stem group Sarraceniaceae likely originated in South America 44–53 million years ago (Mya) (highest posterior density [HPD] estimate = 47 Mya). By 25–44 (HPD = 35) Mya, crown-group Sarraceniaceae appears to have been widespread across North and South America, and Darlingtonia (western North America) had diverged from Heliamphora+Sarracenia (eastern North America+South America). This disjunction and apparent range contraction is consistent with late Eocene cooling and aridification, which may have severed the continuity of Sarraceniaceae across much of North America. Sarracenia and Heliamphora subsequently diverged in the late Oligocene, 14–32 (HPD = 23) Mya, perhaps when direct overland continuity between North and South America became reduced. Initial diversification of South American Heliamphora began at least 8 Mya, but diversification of Sarracenia was more recent (2–7, HPD = 4 Mya); the bulk of southeastern United States Sarracenia originated co-incident with Pleistocene glaciation, <3 Mya. Overall, these results suggest climatic change at different temporal and spatial scales in part shaped the distribution and diversity of this carnivorous plant clade
Response of Solidago canadensis clones to competition
Transplants of ten Solidago canadensis clones were grown under high and low competition in the field to determine whether clones differed in survival, growth, and reproduction under natural conditions. Transplants had higher probability of survival and flowering and were larger in all measures of size when competition was experimentally reduced. Clones differed in almost all these measures of success, but only when variance among transplants within clones was reduced by excluding transplants that experienced heavy herbivore damage. Differences among clones were more apparent under low competition than under high competition, despite higher coefficients of variation within clones under low competition. Adjusting transplant size for initial size (parent ramet rhizome mass) did not change these results, although clones did differ in parent rhizome mass. All of these results suggest that there is little potential for selection to discriminate among these clones. Despite the strong differences in transplant performance between the competition treatments and among clones, the clones did not differ in competitive ability-almost none of the clone x competition interactions were significant. In addition, the measures of success of each clone were usually positively correlated between the high and low competition treatments, suggesting there were no tradeoffs between performance under high and low competition for these clones.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47776/1/442_2004_Article_BF00378042.pd
Biochemical Characterization of HERC2, a HECT-domain E3 Ubiquitin Ligase implicated in Breast Cancer
- …