Geophysical investigation along parts of the Dent and Augill Faults

The areas covered in the present investigation lie near the towns of Brough and Kirkby Stephen. They include parts of the Dent and Augill Faults, which form the western margins of the Askrigg and Alston Blocks respectively. I The higher ground is open moorland used for sheep-grazing and is difficult of access except to cross-country vehicles, but the lower ground is in I agriculturai use , generally as pasture, and is well served by roads and tracks. I The airborne electromagnetic (AEM) survey was restricted to the areas of known mineral veins (Fig. 1) along the Dent and Augill faults. NO geochemical exploration was undertaken because of widespread contamination from the numerous mine dumps. GEOLOGY The northern part of the area shown in Fig. 1 was re-surveyed between 1958 and 1967 (Burgess and Holliday, in press) following the 19th-century primary survey. The southern part has not been completely re-surveyed, although parts of it were revised for the 1 inch to 1 mile scale geological map (Kirkby Stephen sheet 40) published in 1972 and detailed mapping of selected areas has formed part of the present investigations. The area is mainly underlain by Carboniferous rocks (Fig. 2) and details of the successions are given in Figs. 2, 5 and 6. Permo-Triassic deposits are present to the west, j ust beyond the areas of detailed work (Fig. 2). The oldest Carboniferous rocks exposed are the Orton Group, comprising marine limestones with sandstones and shales. The lower part of the overlying Alston Group consists of the massively bedded Great Scar Limestone, about 100 m thick. The succeeding beds comprise alternating limestones, mudstones, siltstones and sandstones deposited in a sequence of cyclothems. These are internally very variable and any one cyclothem is rarely fully developed

Taxonomic and paleoclimatic significance of Late Cretaceous wood from the San Juan Basin, New Mexico.

Fossil wood has been demonstrated to be a powerful tool for studying past environments and biotas. Anatomical structure of silicified woods from Late Cretaceous sediments in northwestern New Mexico was used to conduct a taxonomic survey of plants with secondary growth and tree stature, as well as estimate paleoclimate. A total of 50 specimens compromising both gymnospermous and angiospermous remains were surveyed from deposits within the upper Fruitland and lower Kirtland formations of the San Juan Basin. Anatomical characters were used to designate distinct xylotypes, which were then linked to modern orders or families. Paleoclimate was estimated using three quantitative methods: the Mean Sensitivity statistic (MS), the Vulnerability Index (VI), and regression equations that link eudicot/magnoliid wood to mean annual temperature (MAT). The taxonomic results indicate an abundant but low diversity coniferous flora and less abundant by higher diversity angiosperm flora with xylotypes that have potential links to eight modern orders. These orders ranged from ancestral to derived within the angiosperm phylogeny, and two of the xylotpes represented new records of taxa. The paleoclimate results confirmed a warm, wet environment for the Late Cretaceous. VI values were comparable to modern day tropical trees, implying that water was not a limited resource in the floodplain. The regression equations generated an average MAT of 23.13 ± 5.22oC, a value statistically similar to MAT calculated by leaf physiognomy at 26.8 ± 2.24oC (α = 0.05, p \u3c 0.001). Growth ring sequences analyzed by MS produced an average value of 0.47 ± 0.09, indicating that some of the trees experienced irregular growth. Due to the warm MAT and high VI values, the irregular growth recorded in the conifer wood was probably the result of environmental disturbances, such as flooding or volcanic events, capable of disrupting wood production. This study is the first comprehensive examination of wood from the Late Cretaceous San Juan Basin, and enhances our knowledge of the paleoecology of the region

Early Vessel Evolution and the Diversification of Wood Function: Insights from the Malagasy Canellales

Xylem vessels have long been proposed as a key innovation for the ecological diversification of angiosperms by providing a breakthrough in hydraulic efficiency to support high rates of photosynthesis and growth. However, recent studies demonstrated that angiosperm woods with structurally ‘primitive’ vessels did not have greater whole stem hydraulic capacities as compared to vesselless angiosperms. As an alternative to the hydraulic superiority hypothesis, the heteroxylly hypothesis proposes that subtle hydraulic efficiencies of primitive vessels over tracheids enabled new directions of functional specialization in the wood. However, the functional properties of early heteroxyllous wood remain unknown. We selected the two species of Canellales from Madagascar to test the heteroxylly hypothesis because Canellaceae (represented by Cinnamosma madagascariensis) produces wood with vessels of an ancestral form, while Winteraceae, the sister-clade (represented by Takhtajania perrieri) is vesselless. We found that heteroxylly correlated with increased wood functional diversity related mostly to biomechanical specialization. However, vessels were not associated with greater stem hydraulic efficiency or increased shoot hydraulic capacity. Our results support the heteroxylly hypothesis and highlight the importance integrating a broader ecological context to understand the evolution of vessels

Genetic variation in the methylenetetrahydrofolate reductase gene, MTHFR, does not alter the risk of visual failure in Leber’s hereditary optic neuropathy

Focal neurodegeneration of the optic nerve in Leber hereditary optic neuropathy (LHON) is primarily due to a maternally inherited mitochondrial DNA mutation. However, the markedly reduced penetrance of LHON and segregation pattern of visual failure within families implicates an interacting nuclear genetic locus modulating the phenotype. Folate deficiency is known to cause bilateral optic neuropathy, and defects of folate metabolism have been associated with nonarteritic ischemic optic neuropathy

Novel methods for measuring drought stress of crops in the field

There is currently no available method for land managers to directly and non-destructively measure the water status of plants in the field. Water status of a plant effects plant growth and function and contributes to end-of-season crop yield. We have developed wearable, minimally invasive microneedle sensors that can be precisely placed in leaves of crops, to be used as electrodes for electrical impedance spectroscopy (EIS). EIS measures the passive electrical properties (magnitude and phase shift of impedance) of the leaf. EIS can be used to model biologic tissue as an electrical circuit, where ions in the intra- and extracellular fluid are describes as resistors and the cell membrane is modeled as a capacitor. Our previous work has demonstrated that the magnitude of impedance varies with water availability and can be used to monitor drought stress. In this study, we aim to further our understanding of how phase shift of impedance correlates to tissue damage caused by drought stress. Because EIS models the cell membrane as a capacitor, we predict that changes in phase angle correspond to cell membrane damage. To continue studying EIS as an indicator of plant health, data loggers with microneedle electrodes were deployed in a field of Sorghum bicolor at the New Mexico State Agricultural Science Center in Los Lunas, New Mexico. Two genotypes of S. bicolor were divided into two study groups, one receiving normal irrigation and one receiving half the irrigation. The plant-based EIS data was collected throughout the growing season. Initial results demonstrate that we can collect continuous data directly from plants in the field. Impedance signals mirror expected diurnal cycles from previous lab-based studies. Initial results indicate that phase shift of impedance changes gradually as a leaf progresses through senescence (programmed tissue aging and death) and that phase shift of impedance changes rapidly when a leaf\u27s vascular system is damaged (inhibiting the ability of the leaf to maintain hydration). These initial results indicate that microneedle EIS monitoring of phase angle of impedance may provide land managers with a method to directly monitor plants for drought damage, while distinguishing from typical plant aging

Target Markets for Grain and Cotton Marketing Consultants and Market Information Systems

This paper examines the use of market consultants and market information systems by grain and cotton producers. A model of producer demand for marketing information and consultants is proposed that decomposes price received into exogenous and endogenous components. The analysis is based on a survey of over 1,600 producers. The results suggest that expenditures on market information systems and market consultants are not independent and, more specifically, expenditures on marketing consultants substitute for expenditures on market information systems.expected utility, market information, marketing, risk, Tobit, Marketing,

Soil–Atmosphere Exchange of Nitrous Oxide, Nitric Oxide, Methane, and Carbon Dioxide in Logged and Undisturbed Forest in the Tapajos National Forest, Brazil

Selective logging is an extensive land use in the Brazilian Amazon region. The soil–atmosphere fluxes of nitrous oxide (N2O), nitric oxide (NO), methane (CH4), and carbon dioxide (CO2) are studied on two soil types (clay Oxisol and sandy loam Ultisol) over two years (2000–01) in both undisturbed forest and forest recently logged using reduced impact forest management in the Tapajos National Forest, near Santarem, Para, Brazil. In undisturbed forest, annual soil–atmosphere fluxes of N2O (mean ± standard error) were 7.9 ± 0.7 and 7.0 ± 0.6 ng N cm−2 h−1 for the Oxisol and 1.7 ± 0.1 and 1.6 ± 0.3 ng N cm−2 h−1 for the Ultisol for 2000 and 2001, respectively. The annual fluxes of NO from undisturbed forest soil in 2001 were 9.0 ± 2.8 ng N cm−2 h−1 for the Oxisol and 8.8 ± 5.0 ng N cm−2 h−1 for the Ultisol. Consumption of CH4 from the atmosphere dominated over production on undisturbed forest soils. Fluxes averaged −0.3 ± 0.2 and −0.1 ± 0.9 mg CH4 m−2 day−1 on the Oxisol and −1.0 ± 0.2 and −0.9 ± 0.3 mg CH4 m−2 day−1 on the Ultisol for years 2000 and 2001. For CO2 in 2001, the annual fluxes averaged 3.6 ± 0.4 μmol m−2 s−1 on the Oxisol and 4.9 ± 1.1 μmol m−2 s−1 on the Ultisol. We measured fluxes over one year each from two recently logged forests on the Oxisol in 2000 and on the Ultisol in 2001. Sampling in logged areas was stratified from greatest to least ground disturbance covering log decks, skid trails, tree-fall gaps, and forest matrix. Areas of strong soil compaction, especially the skid trails and logging decks, were prone to significantly greater emissions of N2O, NO, and especially CH4. In the case of CH4, estimated annual emissions from decks reached extremely high rates of 531 ± 419 and 98 ± 41 mg CH4 m−2 day−1, for Oxisol and Ultisol sites, respectively, comparable to wetland emissions in the region. We calculated excess fluxes from logged areas by subtraction of a background forest matrix or undisturbed forest flux and adjusted these fluxes for the proportional area of ground disturbance. Our calculations suggest that selective logging increases emissions of N2O and NO from 30% to 350% depending upon conditions. While undisturbed forest was a CH4 sink, logged forest tended to emit methane at moderate rates. Soil–atmosphere CO2 fluxes were only slightly affected by logging. The regional effects of logging cannot be simply extrapolated based upon one site. We studied sites where reduced impact harvest management was used while in typical conventional logging ground damage is twice as great. Even so, our results indicate that for N2O, NO, and CH4, logging disturbance may be as important for regional budgets of these gases as other extensive land-use changes in the Amazon such as the conversion of forest to cattle pasture

Larva and pupa of Cernotina spicata

The first positively associated larva and pupa of Cernotina are described. Tentative diagnoses are provided for distinguishing them from those of other genera of Nearctic Polycentropodidae, especially Polycentropus s. lat., which Cernotina most strongly resembles

Caddisflies (Insecta: Trichoptera) of Fringing Wetlands of the Laurentian Great Lakes

Fringing wetlands of the Laurentian Great Lakes are subject to natural processes, such as water-level fluctuation and wave-induced erosion, and to human alterations. In order to evaluate the quality of these wetlands over space and time, biological communities are often examined. Ideally, the groups of organisms selected for these evaluations should be resident in the wetlands themselves. Fish are often sampled, but many species are not truly resident, visiting wetlands on an occasional basis to feed or on a seasonal basis to breed. Aquatic vascular plants are perhaps the most common group selected for evaluation. However, in some cases, aquatic plants give a false impression by providing photosynthetic capabilities and structural infrastructure but having greatly diminished herbivore and carnivore communities