Pollination of Pagamea duckei Standl. (Rubiaceae): a functionally dioecious species

The floral biology, pollination and breeding system of Pagamea duckei Standl. (Rubiaceae) were studied at the Reserva Biológica da Campina, Manaus, Amazonas, Brazil. Floral morphology suggested that P. duckei is a distylous species. However, crossing experiments revealed that it is functionally dioecious. The flowers are actinomorphic, yellowish, produce nectar and a sweet odor, which is more intense in the morning. Anthesis started in the morning between 5.00 and 6.00 AM and extended until dusk, when the corolla tube abscissed. The flowers were visited mostly by bees of the genus Melipona. Pagamea duckei is not agamospermic and thus needs pollen vectors for effective pollination. The results of this study strengthen the idea that, in Pagamea, species with distylous flower morphology are actually functionally dioecious

Assessment of registration accuracy between magnetic resonance imaging and three-dimensional trans-rectal ultrasound imaging of prostate cancer

Prostate cancer (PCa) is the third most common cancer in the world and becomes more prevalent with age. A total of 186,320 new prostate cancer cases and 28,660 deaths from cancer are projected to occur in the United States in 2008. Definitive diagnosis of PCa requires a biopsy, and transrectal ultrasound (TRUS) is often used to guide biopsy needle placement. However, TRUS guided biopsies often underestimate or fail to detect the presence of PCa, likely due to inadequate sampling of the prostate resulting from poor visualization of PCa with ultrasound (US). Approximately 10-25% of patients whose first TRUS biopsies were negative are later diagnosed with cancer. This sub-optimal detection performance can be attributed to the underestimation of the Gleason score, a measure of the cancer progression or can be attributed to the low quality images produced by US resulting in poor visualization of the PCa. Magnetic Resonance Imaging (MRI) has been shown to be extremely sensitive and specific for the detection of prostate cancer. However, biopsy under MRI guidance is very difficult to achieve. If MRI images could be registered in real time to 3D TRUS images, the MRI images could be used to guide the biopsy, potentially reducing the rate of false negative biopsies guided by TRUS alone. The goal of this project is to characterize the registration accuracy between 2D T2-weighted (T2-w) MRI and 3D TRUS images.Peer reviewed: YesNRC publication: Ye

Soils, Soil Management and Fertilizer Monographs (Revised 1978)

"This monograph brings together comprehensive and technical information on Minnesota soils and on soil-plant-climate relationships, together with soil and crop management principles. Although prepared for intensified soil training schools conducted periodically by the Minnesota Agricultural Extension Service, the several sections are bound together for reference and to provide a well-rounded information source in a single publication. .." -- Foreword excerpt. This archival publication may not reflect current scientific knowledge or recommendations. Current information available from the University of Minnesota Extension: https://www.extension.umn.edu

A Holocene record of human induced and natural environmental change from Lake Forsyth (Te Wairewa), New Zealand

A 1.2 m sediment core from Lake Forsyth, Canterbury, New Zealand, records the development of the catchment/lake system over the last 7000 years, and its response to anthropogenic disturbance following European settlement c. 1840 AD. Pollen was used to reconstruct catchment vegetation history, while foraminifera, chironomids, Trichoptera, and the abundance of Pediastrum simplex colonies were used to infer past environmental conditions within the lake. The basal 30 cm of core records the transition of the Lake Forsyth Basin from a tidal embayment to a brackish coastal lake. Timing of closure of the lake mouth could not be accurately determined, but it appears that Lake Forsyth had stabilised as a slightly brackish, oligo-mesotrophic shallow lake by about 500 years BP. Major deforestation occurred on Banks Peninsula between 1860 AD and 1890 AD. This deforestation is marked by the rapid decline in the main canopy trees (Prumnopitys taxifolia (matai) and Podocarpus totara/hallii (totara/mountain totara), an increase in charcoal, and the appearance of grasses. At around 1895 AD, pine appears in the record while a willow (Salix spp.) appears somewhat later. Redundancy analysis (RDA) of the pollen and aquatic species data revealed a significant relationship between regional vegetation and the abundance of aquatic taxa, with the percentage if disturbance pollen explaining most (14.8%) of the constrained variation in the aquatic species data. Principle components analysis (PCA) of aquatic species data revealed that the most significant period of rapid biological change in the lakes history corresponded to the main period of human disturbance in the catchment. Deforestation led to increased sediment and nutrient input into the lake which was accompanied by a major reduction in salinity. These changes are inferred from the appearance and proliferation of freshwater algae (Pediastrum simplex), an increase in abundance and diversity of chironomids, and the abundance of cases and remains from the larvae of the caddisfly, Oecetis unicolor. Eutrophication accompanied by increasing salinity of the lake is inferred from a significant peak and then decline of P. simplex, and a reduction in the abundance and diversity of aquatic invertebrates. The artificial opening of the lake to the Pacific Ocean, which began in the late 1800s, is the likely cause of the recent increase in salinity. An increase in salinity may have also encouraged blooms of the halotolerant and hepatotoxic cyanobacteria Nodularia spumigena