95 research outputs found
Porotrichum saotomense sp. nov. (Neckeraceae) and other additions to the moss flora of SĂŁo TomĂ© & PrĂncipe, Gulf of Guinea, West Africa
Peer reviewe
Mawenzhangia thamnobryoides (Bryophyta, Lembophyllaceae), a new moss genus and species from the Shangri-la region of Yunnan Province, China
Mawenzhangia thamnobryoides gen. et sp. nov. (Bryophyta, Lembophyllaceae) is described based on collections from Yunnan, China. It is known from the Niru River watershed and grows on boulders just above the high water zone but can also be seasonally inundated. According to ITS sequences it is closely related to Nogopterium gracile (Pterogonium g.), but can be distinguished by the loosely patent and elliptic vs. imbricate and ovate leaves; much longer, single costa; thinner-walled and less strongly prorate laminal cells; and much smaller group of alar cells. Mawenzhangia thamnobryoides is illustrated in line drawings and an identification key to Chinese genera of the Lembophyllaceae is provided.Peer reviewe
Contributions to the moss families Neckeraceae and Pterobryaceae of Bhutan
Three species previously thought to be Chinese endemics from the easternmost Himalayas are reported from Bhutan: Shevockia inunctocarpa Enroth & M.C. Ji and Taiwanobryum yunnanense (Enroth) Enroth comb. nov. of the Neckeraceae, and Calyptothecium acostatum J.X. Luo of the Pterobryaceae. The latter, originally described from Xizang, is also reported from Yunnan, China. Additionally, Noguchiodendron sphaerocarpum (Nog.) Ninh & PĂłcs is reported for the second time (since 1971) from Bhutan.Peer reviewe
Astralagus ertterae (Fabaceae), a New Species from the Southern Sierra Nevada
Astragalus ertterae, a new species from pinyon pine woodlands, southern Sierra Nevada, Kern County, California, is described and illustrated. This remarkable new species is morphologically closest to A. bicristatus in sect. Bicristati but differs in its dwarf stature, pilose indumentum, short peduncles, somewhat smaller flowers, and especially in a pod only half as long and proportionately twice as plump
Light Loaded Automated Guided Vehicle
The objective of the locomotion system was to design and implement the mechanical, electrical, and software related functions to ensure the LLAGV had the capability of maneuvering its surroundings. The LLAGV’s motors were represented in an open loop transfer function to utilize RPM feedback and a compensator when needed. The modeled compensator helped control the LLAGV’s speed and acceleration, enabling further control of the LLAGV. The internal circuitry has the means to properly distributed power to all components and allowed the user to control the LLAGV to their desire. The application software within the LLAGV locomotion system (LLAGV-LS) had consideration for distance and angle variation, provided by the navigation system (NS) team where this information was pulled from an in-memory database. Changing the angle and distance, from the user, was done using motor control theory and application. The data along with feedback from the system provided a reliable and predictable means of driving the LLAGV’s traction control system as well as incorporating input from the user and delivering a source of feedback to the user, ultimately creating a cohesive, intuitive interface for the user to take advantage of the convenience the LLAGV offered. The LLAGV also had basic object detection features in which the NS informs the LS Team B would inform Team A of an object in front of the LLAGV. The LLAGV then conducts the actions necessary to avoid the object. Key features are as included below. LLAGV maintains a distance of 3 to 10 feet with an average of 3 ft/sec LED lights dictate the state of charge and state and direction intent LLAGV lasts for a minimum of two hours at a full charge LLAGV carries a light load of up to 30 pound
Dudleya Cymosa Subsp. Costafolia (Crassulaceae), A New Subspecies from the Southern Sierra Nevada, Tulare County, California
Dudleya cymosa subsp. costafolia, a new subspecies from the southern Sierra Nevada, Tulare County, California, is described and illustrated. Along with bright yellow flowers, the cespitose plant produces numerous, small rosettes with rib-shaped linear to linear-oblanceolate leaves, which are unique to the subspecies. The authors have searched numerous other rock outcrops, especially limestone, in the general area for additional plants with no success. Dudleya cymosa subsp. costafolia evidently is restricted to a solitary limestone outcrop north of the South Fork of the Middle Fork of the Tule River
Rediscovery of the monospecific moss genus Cyptodontopsis (Cryphaeaceae) in China: a species restricted to flood plain habitats
Peer reviewe
What is Clastobryella tenella M.Fleisch.?
The moss Clastobryella tenella M.Fleisch. based on a collection from Java has remained poorly understood since its original description. Microscopic examination of the type material in the Fleischer Herbarium within the Farlow Herbarium of Harvard University concluded that the exceedingly fragmentary type material best represents juvenile plants of Gammiella tonkinensis (Broth. & Par.) B.C. Tan
Alterations in MDCK and LLC-PK1 Cells Exposed to Oxalate and Calcium Oxalate Monohydrate Crystals
Structural analysis of human kidney stones reveals the presence of cellular membranes and other cell fragments. Experimentally, calcium oxalate crystallization is facilitated when an exogenous nephrotoxin is given with ethylene glycol, thus providing cellular degradation products to act as heterogenous nuclei. In this report, we tested whether oxalate alone could act as a cell toxin capable of producing damaged cells without the presence of an exogenous agent. Cultured LLC-PK1 and MDCK cells, when exposed to 1.0 mmol KOx, a concentration at the limit of metastability for calcium oxalate nucleation, were severely damaged as measured by specific lactate dehydrogenase (LDH) release in the spent media and by trypan blue exclusion. This effect was magnified by the addition of pre-formed calcium oxalate monohydrate crystals; the injury was significantly amplified when compared to exposure to oxalate alone. Scanning electron microscopy studies illustrated attachment of crystals to cells with loss of cell-to-cell and cell-to-substrate contact, as cells were released from the monolayer. In both oxalate and combined crystal-oxalate studies, more cells were released from the monolayer and exhibited considerably more damage when compared to controls. Oxalate, at the limit of metastability for calcium oxalate, is a cell toxin and can produce cellular degradation products. This effect is increased significantly by the addition of calcium oxalate monohydrate crystals
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