Sample records for northern vernal equinox

  1. Traveling ionospheric disturbances observed by Kharkiv and Millstone Hill incoherent scatter radars near vernal equinox and summer solstice

    NASA Astrophysics Data System (ADS)

    Panasenko, Sergii V.; Goncharenko, Larisa P.; Erickson, Philip J.; Aksonova, Kateryna D.; Domnin, Igor F.

    2018-07-01

    We present the results of comparative study of traveling ionospheric disturbances (TIDs) obtained at middle latitudes of different longitudinal sectors during two coordinated observational campaigns. The joint measurements were conducted near the vernal equinox and summer solstice in 2016 using Kharkiv (49.6 N, 36.3 E) and Millstone Hill (42.6 N, 288.5 E) incoherent scatter radars. The same methods and software were used for analysis of both data sets to ensure consistency. We found that TIDs with periods of 40-80 min are observed during all measurements and concentrated predominantly near the sunrise and sunset terminators over both sites. There is no obvious relationship between the observed wave processes and variations in the auroral electrojet. Absolute and relative amplitudes, time of appearance, durations and phase differences of TIDs show strong height and seasonal variability. Relative amplitudes are substantially greater over Millstone Hill, whereas higher absolute amplitudes are observed over Kharkiv. During the summer solstice, the overall wave activity is smaller than during vernal equinox. Additional joint observations are needed to identify the seasonal and longitudinal dependences of TID characteristics.

  2. Vernal Point and Plate Tectonics: Indo-Australian

    NASA Astrophysics Data System (ADS)

    Chavez C, Teodosio; Chavez-Sumarriva, Israel; Chavez S, Nadia

    2013-04-01

    A precession coordinate system (eccentricity -100Ka, obliquity -40Ka and precession -25Ka) developed by Milankovicht was the precession of the equinoxes, where the vernal point retrograde 1° every 72 years approximately and enter (0°) into the Aquarius constellation on March 20, 1940. On earth this entry was verify through: a) stability of the magnetic equator in the south central zone of Peru and in the north zone of Bolivia, b) the greater intensity of equatorial electrojet (EEJ) in Peru and Bolivia since 1940. The vernal point is a maximum conductivity sensitive axis in the EEJ given at the equinoxes. There was a relationship between the equatorial electrojet - magnetic equator - crust, and besides there was a long history of studies of coupling between earthquake-ionosphere that can be founded in the following revisions: Liperovsky et al. (1990); Gaivoronskaya (1991); Liperovsky et al. (1992); Parrot et al. (1993); Pulinets et al. (1994) and Gokhberg et al. (1995). In IUGG (2007), Cusco was propose as a prime meridian (72° W == 0°) that was parallel to the Andes; the objective was to synchronize the earth sciences phenomena (e.g. geology, geophysics, etc.). The coordinate system had the vernal point from meridian (72° W == 0°) and March 20, 1940. The retrograde movement of the vernal point was the first precessional degree (2012 = 1940 + 72); from the new prime meridian (72° W == 0°) it has obtained the opposite meridian (72° E == 180°). The first precessional degree (2012) near the meridian (72 ° E) was related to the date of April 11, 2012 where a massive earthquake of 8.6 on the Richter scale, followed by several aftershocks, one of 8.2 degrees struck Indonesia with epicenter near Banda Aceh. Five months after that date, Matthias Delescluse et.al (2012), Han Yue et.al (2012), and Fred F. Pollitz et.al, (2012), explained that the two violent earthquakes would be evidence of a break in the Indo-Australian Plate Tectonics caused earthquakes around

  3. Hydrology of vernal pools at three sites, southern Sacramento Valley

    DOT National Transportation Integrated Search

    2005-04-01

    The subsurface hydrology of vernal pools at three vernal pool complexes was investigated during three wet seasons in 2002- : 2004. The complexes were at Gridley Ranch, Valensin Ranch, and the Mather Field in northern California. The selected : comple...

  4. Dissipation of Titans north polar cloud at northern spring equinox

    USGS Publications Warehouse

    Le, Mouelic S.; Rannou, P.; Rodriguez, S.; Sotin, Christophe; Griffith, C.A.; Le, Corre L.; Barnes, J.W.; Brown, R.H.; Baines, K.H.; Buratti, B.J.; Clark, R.N.; Nicholson, P.D.; Tobie, G.

    2012-01-01

    Saturns Moon Titan has a thick atmosphere with a meteorological cycle. We report on the evolution of the giant cloud system covering its north pole using observations acquired by the Visual and Infrared Mapping Spectrometer onboard the Cassini spacecraft. A radiative transfer model in spherical geometry shows that the clouds are found at an altitude between 30 and 65 km. We also show that the polar cloud system vanished progressively as Titan approached equinox in August 2009, revealing at optical wavelengths the underlying sea known as Kraken Mare. This decrease of activity suggests that the north-polar downwelling has begun to shut off. Such a scenario is compared with the Titan global circulation model of Rannou et al. (2006), which predicts a decrease of cloud coverage in northern latitudes at the same period of time. ?? 2011 Elsevier Ltd. All rights reserved.

  5. Long term evaluation of characteristics in an artificial Northern California vernal pool system.

    DOT National Transportation Integrated Search

    2003-04-01

    This report (Phase II) completes an evaluation of 3 sets of 5 artificial vernal pools located on Travis AFB in Solano County CA. The research was done to determine if artificial vernal pools constructed on Travis AFB in 1993 maintained vernal pool ch...

  6. Vernal Point and Anthropocene

    NASA Astrophysics Data System (ADS)

    Chavez-Campos, Teodosio; Chavez S, Nadia; Chavez-Sumarriva, Israel

    2014-05-01

    The time scale was based on the internationally recognized formal chronostratigraphical /geochronological subdivisions of time: The Phanerozoic Eonathem/Eon; the Cenozoic Erathem/Era; the Quaternary System/Period; the Pleistocene and Holocene Series/Epoch. The Quaternary was divided into: (1) The Pleistocene that was characterized by cycles of glaciations (intervals between 40,000 and 100,000 years). (2) The Holocene that was an interglacial period that began about 12,000 years ago. It was believed that the Milankovitch cycles (eccentricity, axial tilt and the precession of the equinoxes) were responsible for the glacial and interglacial Holocene periods. The magnetostratigraphic units have been widely used for global correlations valid for Quaternary. The gravitational influence of the sun and moon on the equatorial bulges of the mantle of the rotating earth causes the precession of the earth. The retrograde motion of the vernal point through the zodiacal band is 26,000 years. The Vernal point passes through each constellation in an average of 2000 years and this period of time was correlated to Bond events that were North Atlantic climate fluctuations occurring every ≡1,470 ± 500 years throughout the Holocene. The vernal point retrogrades one precessional degree approximately in 72 years (Gleissberg-cycle) and approximately enters into the Aquarius constellation on March 20, 1940. On earth this entry was verify through: a) stability of the magnetic equator in the south central zone of Peru and in the north zone of Bolivia, b) the greater intensity of equatorial electrojet (EEJ) in Peru and Bolivia since 1940. With the completion of the Holocene and the beginning of the Anthropocene (widely popularized by Paul Crutzen) it was proposed the date of March 20, 1940 as the beginning of the Anthropocene. The date proposed was correlated to the work presented in IUGG (Italy 2007) with the title "Cusco base meridian for the study of geophysical data"; Cusco was

  7. Effects of vernal equinox solar eclipse on temperature and wind direction in Switzerland

    NASA Astrophysics Data System (ADS)

    Eugster, Werner; Emmel, Carmen; Wolf, Sebastian; Buchmann, Nina; McFadden, Joseph P.; Whiteman, Charles David

    2017-12-01

    The vernal equinox total solar eclipse of 20 March 2015 produced a maximum occultation of 65.8-70.1 % over Switzerland during the morning hours (09:22 to 11:48 CET). Skies were generally clear over the Swiss Alps due to a persistent high-pressure band between the UK and Russia associated with a rather weak pressure gradient over the continent. To assess the effects of penumbral shading on near-surface meteorology across Switzerland, air temperature data measured at 10 min intervals at 184 MeteoSwiss weather stations were used. Wind speed and direction data were available from 165 of these stations. Additionally, six Swiss FluxNet eddy covariance flux (ECF) sites provided turbulent measurements at 20 Hz resolution. During maximum occultation, the temperature drop was up to 5.8 K at a mountain site where cold air can pool in a topographic depression. The bootstrapped average of the maximum temperature drops of all 184 MeteoSwiss sites during the solar eclipse was 1.51 ± 0.02 K (mean ± SE). A detailed comparison with literature values since 1834 showed a temperature decrease of 2.6 ± 1.7 K (average of all reports), with extreme values up to 11 K. On fair weather days under weak larger-scale pressure gradients, local thermo-topographic wind systems develop that are driven by small-scale pressure and temperature gradients. At one ECF site, the penumbral shading delayed the morning transition from down-valley to up-valley wind conditions. At another site, it prevented this transition from occurring at all. Data from the 165 MeteoSwiss sites measuring wind direction did not show a consistent pattern of wind direction response to the passing of the penumbral shadow. These results suggest that the local topographic setting had an important influence on the temperature drop and the wind flow patterns during the eclipse. A significant cyclonic effect of the passing penumbral shadow was found in the elevation range ≈ 1700-2700 m a. s. l., but

  8. Vertical cloud structure of Uranus from UKIRT/UIST observations and changes seen during Northern Spring Equinox in 2007

    NASA Astrophysics Data System (ADS)

    Irwin, P. G. J.; Teanby, N. A.; Davis, G. R.

    2008-09-01

    Uranus has a very high obliquity of 98 degrees and a very small amount of residual internal heat left over from its formation. Hence, the circulation of its atmosphere is strongly affected by seasonal changes in solar irradiation. Uranus reached its northern spring equinox in December 2007 and at the planet's last equinox in 1965 there were indications of a substantial change in the planet's appearance. Ground-based instrumentation has improved dramatically since 1965 and thus there has been great international interest in monitoring the cloud structure of Uranus through this equinox period to monitor any rapid variations that may occur this time. New near-infrared spectra of Uranus were observed in August/September 2006 and in June 2007 using the UIST instrument on the United Kingdom Infrared Telescope (UKIRT). Spectra (in Long Slit mode) were recorded between 1 and 2.5 microns with the slit aligned with the planet's central meridian to determine any north-south variations of Uranus' cloud structure. In addition, context images were also recorded to note the position of discrete mid-latitude clouds to ensure that these were not confused with any general latitudinal variation (Fig. 1). We here present retrievals of the latitudinal variation of Uranus' vertical cloud structure from these data using an optimal estimation retrieval model, NEMESIS[1], together with new methane absorption coefficients[2] and a Matrix Operator multiple scattering model. Apart from some small storms at both southern and northern mid-latitudes, some reaching the 200 mbar pressure level, indicating vigorous convection, we find that the data are generally best fitted either with two cloud layers, one at ~2 - 3 bars and a second deeper cloud layer at ~8 bars, or alternatively by a single extended cloud spanning this pressure range (Fig. 2.). In the bright band at 45ºS we find that the opacity in the 2 -3 bar region is increased, while that deeper levels decreased slightly[3]. Comparing

  9. 78 FR 53487 - Equinox Funds Trust and Equinox Institutional Asset Management LP; Notice of Application

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-29

    ... Funds Trust and Equinox Institutional Asset Management LP; Notice of Application August 23, 2013. AGENCY...: Equinox Funds Trust (the ``Trust'') and Equinox Institutional Asset Management LP (the ``Initial Adviser... Institutional Asset Management LP, 47 Hulfish Street, Suite 510, Princeton, NJ 08542; Daniel Prezioso, Equinox...

  10. Maternal vernalization and vernalization-pathway genes influence progeny seed germination.

    PubMed

    Auge, Gabriela A; Blair, Logan K; Neville, Hannah; Donohue, Kathleen

    2017-10-01

    Different life stages frequently respond to the same environmental cue to regulate development so that each life stage is matched to its appropriate season. We investigated how independently each life stage can respond to shared environmental cues, focusing on vernalization, in Arabidopsis thaliana plants. We first tested whether effects of rosette vernalization persisted to influence seed germination. To test whether genes in the vernalization flowering pathway also influence germination, we assessed germination of functional and nonfunctional alleles of these genes and measured their level of expression at different life stages in response to rosette vernalization. Rosette vernalization increased seed germination in diverse ecotypes. Genes in the vernalization flowering pathway also influenced seed germination. In the Columbia accession, functional alleles of most of these genes opposed the germination response observed in the ecotypes. Some genes influenced germination in a manner consistent with their known effects on FLOWERING LOCUS C gene regulation during the transition to flowering. Others did not, suggesting functional divergence across life stages. Despite persistent effects of environmental conditions across life stages, and despite pleiotropy of genes that affect both flowering and germination, the function of these genes can differ across life stages, potentially mitigating pleiotropic constraints and enabling independent environmental regulation of different life stages. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

  11. Vernal Pool Lessons and Activities.

    ERIC Educational Resources Information Center

    Childs, Nancy; Colburn, Betsy

    This curriculum guide accompanies Certified: A Citizen's Step-by-Step Guide to Protecting Vernal Pools which is designed to train volunteers in the process of identifying vernal pool habitat so that as many of these pools as possible can be certified by the Massachusetts Natural Heritage and Endangered Species Program. Vernal pools are a kind of…

  12. Vernal Pool Conservation in Connecticut: An Assessment and Recommendations

    NASA Astrophysics Data System (ADS)

    Preisser, Evan L.; Kefer, Jennifer Yelin; Lawrence, Jessica D.; Clark, Tim W.

    2000-11-01

    Vernal pools, a variety of ephemeral wetlands, are threatened in many areas of the United States. As habitat fragmentation and degradation increase, some vernal pool amphibian species are declining in numbers. Uneven implementation of state regulations further hampers effective conservation. To prevent further species decline and vernal pool loss, we evaluated alternatives for improving vernal pool conservation. We used transcripts from a recent vernal pool conference, interviews with members of relevant interest groups, and a literature review to determine opportunities for and constraints on improving vernal pool conservation policy. Participants from different interest groups had very diverse views about appropriate protection strategies. We have examined these different perspectives and alternatives and offer policy recommendations on both the state and local level. These recommendations can foster awareness of vernal pools as unique habitats, increase protection of these areas, and expand citizen participation in the vernal pool regulatory process.

  13. Taurus

    NASA Astrophysics Data System (ADS)

    Murdin, P.

    2000-11-01

    (the Bull; abbrev. Tau, gen. Tauri; area 797 sq. deg.) A northern zodiacal constellation which lies between Aries and Orion, and culminates at midnight in late November. It is one of the oldest constellations, dating back to when the Sun was in that part of the sky at the vernal (spring) equinox, between about 4000 and 1800 BC. Later, in Greek mythology, it was identified with the form assumed by...

  14. Vernal conjunctivitis

    MedlinePlus

    Vernal conjunctivitis often occurs in people with a strong family history of allergies. These may include allergic rhinitis , asthma , and eczema. It is most common in young males, and most often occurs during the spring and ...

  15. Component-resolved diagnostics in vernal conjunctivitis.

    PubMed

    Armentia, Alicia; Sanchís, Eugenia; Montero, Javier A

    2016-10-01

    Conventional diagnostic tests in allergy are insufficient to clarify the cause of vernal conjunctivitis. Component-resolved diagnostic (CRD) by microarray allergen assay may be useful in detecting allergens that might be involved in the inflammatory process. In a recent trial in patients suffered from eosinophilic esophagitis, after 2 years of the CRD-guided exclusion diet and specific immunotherapy, significant clinical improvement was observed, and 68% of patients were discharged (cure based on negative biopsy, no symptoms, and no medication intake). Our new objective was to evaluate IgE-mediated hypersensitivity by CRD in tears and serum from patients with vernal conjunctivitis and treat patients with identified triggering allergens by specific immunotherapy. Twenty-five patients with vernal conjunctivitis were evaluated. The identified triggering allergens were n Lol p 1 (11 cases), n Cyn d 1 (eight cases), group 4 and 6 grasses (six cases) and group 5 of grasses (five cases). Prick test and pollen IgE were positive in one case. Clinical improvement was observed in 13/25 vernal conjunctivitis patients after 1-year specific immunotherapy. CRD seems to be a more sensitive diagnostic tool compared with prick test and IgE detection. Specific CRD-led immunotherapy may achieve clinical improvements in vernal conjunctivitis patients.

  16. Continuous Hydrologic and Water Quality Monitoring of Vernal Ponds.

    PubMed

    Mina, Odette; Gall, Heather E; Chandler, Joseph W; Harper, Jeremy; Taylor, Malcolm

    2017-11-13

    Vernal ponds, also referred to as vernal pools, provide critical ecosystem services and habitat for a variety of threatened and endangered species. However, they are vulnerable parts of the landscapes that are often poorly understood and understudied. Land use and management practices, as well as climate change are thought to be a contribution to the global amphibian decline. However, more research is needed to understand the extent of these impacts. Here, we present methodology for characterizing a vernal pond's morphology and detail a monitoring station that can be used to collect water quantity and quality data over the duration of a vernal pond's hydroperiod. We provide methodology for how to conduct field surveys to characterize the morphology and develop stage-storage curves for a vernal pond. Additionally, we provide methodology for monitoring the water level, temperature, pH, oxidation-reduction potential, dissolved oxygen, and electrical conductivity of water in a vernal pond, as well as monitoring rainfall data. This information can be used to better quantify the ecosystem services that vernal ponds provide and the impacts of anthropogenic activities on their ability to provide these services.

  17. [Epigenetics of plant vernalization regulated by non-coding RNAs].

    PubMed

    Zhang, Shao-Feng; Li, Xiao-Rong; Sun, Chuan-Bao; He, Yu-Ke

    2012-07-01

    Many higher plants must experience a period of winter cold to accomplish the transition from vegetative to reproductive growth. This biological process is called vernalization. Some crops such as wheat (Triticum aestivum L.) and oilseed rape (Brassica napus L.) produce seeds as edible organs, and therefore special measures of rotation and cultivation are necessary for plants to go through an early vernalization for flower differentiation and development, whereas the other crops such as Chinese cabbage (B rapa ssp. pekinenesis) and cabbage (Brassica napus L.) produce leafy heads as edible organs, and additional practice should be taken to avoid vernalization for a prolonged and fully vegetative growth. Before vernalization, flowering is repressed by the action of a gene called Flowering Locus C (FLC). This paper reviewed the function of non-coding RNAs and some proteins including VRN1, VRN2, and VIN3 in epigenetic regulation of FLC during vernalization.

  18. Assessing ecological risk at a hazardous waste site containing vernal pools

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    DeLong, T.; Millard, J.; Timmer, E.

    1995-12-31

    An ecological risk assessment was conducted for a Superfund site in central California. As part of this assessment an evaluation of vernal pools was conducted. Vernal pools are amphibious ecosystems that support unique biotic communities. Many of the endemic species associated with vernal pools in central California are currently listed as state or Federally endangered, threatened, or rare species and include: Contra Costa goldfields (Lasthenia conjugens), vernal pool fairy shrimp (Branchinecta lynchl), vernal pool tadpole shrimp (Lepidurus packardi) and the California tiger salamander (Ambystoma tigrinum califomiense). The protection of these habitats is essential for the preservation of the special statusmore » species dependent on them for survival. As part of the risk assessment, vernal pools in the study area were identified and surveyed for special status flora and fauna for two consecutive years. Information regarding the relative quality of each pool was also collected. In order to assess potential impacts from chemical exposures to communities inhabiting these vernal pools, a weight-of-evidence approach was employed that included: evaluation of vernal pool biological composition; assessment of physical and chemical conditions; invertebrate sediment toxicity evaluations, and Frog Embryo Teratogenesis Analysis -- Xenopus (FETAX) testing.« less

  19. Hydric soils in a southeastern Oregon vernal pool

    USGS Publications Warehouse

    Clausnitzer, D.; Huddleston, J.H.; Horn, E.; Keller, Michael; Leet, C.

    2003-01-01

    Vernal pools on the High Lava Plain of the northern Great Basin become ponded in most years, but their soils exhibit weak redoximorphic features indicative of hydric conditions. We studied the hydrology, temperature, redox potentials, soil chemistry, and soil morphology of a vernal pool to determine if the soils are hydric, and to evaluate hydric soil field indicators. We collected data for 3 yr from piezometers, Pt electrodes, and thermocouples. Soil and water samples were analyzed for pH, organic C, and extractable Fe and Mn. Soils were ponded from January through April or May, but subsurface saturation was never detected. Soil temperatures 50 cm below the surface rose above 5??C by March. Clayey Bt horizons perched water and limited saturation to the upper 10 cm. Redox potentials at a 5-cm depth were often between 200 and 300 mV, indicating anaerobic conditions, but producing soluble Fe2+ concentrations <1 mg L-1. Extractable soil Fe contents indicated Fe depletion from pool surface horizons and accumulation at or near the upper Bt1 horizon. Depletions and concentrations did not satisfy the criteria of any current hydric soil indicators. We recommend development of new indicators based on acceptance of fewer, less distinct redox concentrations for recognition of a depleted A horizon, and on presence of a thin zone containing redox concentrations located in the upper part of the near-surface perching horizon.

  20. Travelling Ionospheric Disturbances Observed During Sudden Stratospheric Warming, Equinox and Solstice Periods with Kharkiv and Millstone Hill Incoherent Scatter Radars

    NASA Astrophysics Data System (ADS)

    Goncharenko, L. P.; Panasenko, S.; Aksonova, K.; Erickson, P. J.; Domnin, I. F.

    2016-12-01

    Travelling ionospheric disturbances (TIDs) play a key role in the coupling of different ionospheric regions through momentum an energy transfer. They are thought to be mostly associated with atmospheric gravity waves and are known to strongly affect radio propagation conditions. The incoherent scatter (IS) method enables TIDs detection in such ionospheric parameters as electron density, ion and electron temperatures, and plasma velocity along radar beam, thus providing critical information needed to examine different hypothesis about association of TIDs with their sources. In 2016, several joint measuring campaigns were conducted using Kharkiv (49.6 N, 36.4 E) and Millstone Hill (42.6 N, 288.5 E) IS radars. These campaigns covered the periods of sudden stratospheric warnings (SSW) in February, vernal equinox and summer solstice. For consistency, the data acquired by radars were processed using the same data analysis methods. The results obtained show the TIDs to be detected throughout all observation intervals in February measurements. The differences found in the behavior of TIDs over Kharkiv and Millstone Hill sites may be partially explained by variations in stratospheric wind velocity vectors during SSW period. As for March equinox and June solstice, the prevailing TIDs are observed near solar terminators. Their periods vary mostly in the range of 40 - 80 minutes, relative amplitudes are about 0.05 - 0.3 of the background electron density, and the maximum values are observed at the heights of 200 - 250 km. Systematic long-term observations of wave processes in the ionosphere with multiple IS facilities can reveal interhemispheric variability in TID parameters, give better understanding the mechanisms of TID generation and propagation, and improve regional and global ionospheric models.

  1. Vernal Pools Detection Using High-Resolution LiDAR Data and Aerial Imagery in Hubbardston, Massachusetts

    NASA Astrophysics Data System (ADS)

    Jiang, Jiaxin

    Vernal pool refers to temporary or semi-permanent pools that occur in surface depressions without permanent inlets or outlets. Because they periodically dry out, vernal pools are free of fish and essential to amphibians, some reptiles, birds, and mammals for breeding habitats. In Massachusetts, vernal pool habitats are found in woodland depressions, swales or kettle holes where water is contained for at least two months in most years. However, vernal pools are delicate ecosystems. These systems are fragile to human activities such as urbanization. Understanding the current situation of vernal pools helps city planners make wiser decisions. This study focuses on identifying vernal pools in the state of Massachusetts with high-resolution light detection and ranging (LiDAR) data and aerial imagery. By using high-resolution light detection and ranging data, aerial imagery, land use data, the MassDEP Hydrography layer and the Soil Survey Geographic Database, the approach located over 1800 potential vernal pools in a 108 km 2 study area in Massachusetts. The assessment of the study result shows the commission rate was 5.6% and omission rate was 7.1%. This method provides an efficient way of locating vernal pools over large areas.

  2. Weather-related effects on woodland vernal pool hydrology and hydroperiod

    Treesearch

    Robert T. Brooks

    2004-01-01

    Woodland vernal pools occur commonly throughout northeastern North America. These pools provide preferred breeding habitat for mole salamanders (Ambystoma spp.) and wood frogs (Rana sylvatica) and support an abundant and diverse macroinvertebrate fauna. Vernal pool hydrology, and especially hydro-period or duration of the wet phase, affects the composition and...

  3. [Effects of temperature on leaf lettuce vernalization.

    PubMed

    Zhang, Li Li; Hao, Jing Hong; Han, Ying Yan; Liu, Chao Jie; Su, He Nan; Li, Pan Pan; Sun, Yan Chuan; Fan, Shuang Xi

    2016-11-18

    To investigate the effects of different temperatures on the vernalization of leaf lettuce, and declare their type, two easy bolting leaf lettuce varieties of GB-30 and GB-31 were selected as material, which were treated by 4 ℃, 20 ℃ and 25 ℃ for 20 d respectively and afterwards treated by high temperature stress. The process of flower bud differentiation was observed by using paraffin section technology, and combined the condition of bolting and flowering to estimate whether or not it underwent vernalization, and defined its vernalization type. The results showed that, two varieties of GB-30 and GB-31 appeared bolting to different degrees at the 8 th day under high temperature stress after temperature treatments in the early stage. Different temperatures in the early stage all made flower bud differentiated of two varieties. 4 ℃ treatment did not advance the flower bud differentiation, while the high temperature in later time accelerated this progress. Furthermore, the days required for the two varieties to complete development stages differed under different temperature treatments. The effective accumulated temperature whether from pregermination to flowering or from high temperature stress to flowering of two varieties were also different. The leaf lettuce without low temperature treatment in early stage could enter into the flower bud differentiation, bolting, budding and flowering stages, and it could be considered as non-low temperature vernalization plant. The high temperature treatment in later stage could obviously promote its bolting and flowering. In addition, the effective accumulated temperature had to reach about 2500 ℃·d from germination to blossom.

  4. A methyltransferase required for proper timing of the vernalization response in Arabidopsis

    DOE PAGES

    Lee, Joohyun; Yun, Jae-Young; Zhao, Wei; ...

    2015-01-20

    Prolonged exposure to winter cold enables flowering in many plant species through a process called vernalization. In Arabidopsis, vernalization results from the epigenetic silencing of the floral repressor FLOWERING LOCUS C (FLC) via a Polycomb Repressive Complex 2 (PRC2)-mediated increase in the density of the epigenetic silencing mark H3K27me3 at FLC chromatin. During cold exposure, a gene encoding a unique, cold-specific PRC2 component, VERNALIZATION INSENSITIVE 3 (VIN3), which is necessary for PRC2-mediated silencing of FLC, is induced. In this paper, we show that SET DOMAIN GROUP 7 (SDG7) is required for proper timing of VIN3 induction and of the vernalizationmore » process. Loss of SDG7 results in a vernalization-hypersensitive phenotype, as well as more rapid cold-mediated up-regulation of VIN3. In the absence of cold, loss of SDG7 results in elevated levels of long noncoding RNAs, which are thought to participate in epigenetic repression of FLC. Furthermore, loss of SDG7 results in increased H3K27me3 deposition on FLC chromatin in the absence of cold exposure and enhanced H3K27me3 spreading during cold treatment. In conclusion, SDG7 is a negative regulator of vernalization, and loss of SDG7 creates a partially vernalized state without cold exposure.« less

  5. HYDROLOGY AND LANDSCAPE CONNECTIVITY OF VERNAL POOLS OF THE GLACIATED NORTHEAST

    EPA Science Inventory

    The hydrologic budget of a vernal pool influences many aspects of pool function and is the basis for pool life. Although alternating wet and dry periods occur in most wetlands, vernal pools can experience extreme moisture fluctuations. This variability results from intra- and i...

  6. Ionospheric Response during the Equinox and the Solstice Periods over Turkey

    NASA Astrophysics Data System (ADS)

    Cinar, Ali; Arikan, Feza; Karatay, Secil

    2016-07-01

    Ionosphere is a layer of the atmosphere which is an integral part of whole geomagnetic and geological framework. Ionosphere responds to solar EUV radiation by varying within the diurnal 24-hour period, seasonal periods and annually and over the 11-year cycle of solar activity. Therefore, relying on the evidence that there have been variations observed in the VLF, LF and HF signals, magnetic field of the earth and in the local electric field, a unified theory, that would explain the mechanism and cause of the disturbance in the layers of atmosphere, is a widely investigated research topic. In this study, the behavior of the IONOLAB- Total Electron Content (TEC) estimates obtained from dual frequency ground-based GPS receivers are examined using Symmetric Kullback Leibler Distance (SKLD) and L2 Norm (L2N) methods both for the periods that include the equinox and solstice between 2010 and 2012 for Turkey. The solstice and equinox periods within the same year and the solstice periods and the equinox periods from 2010 to 2012 are compared with each other for 18 Turkish National Permanent GPS Network (TNPGN-Active) stations. It is observed that the difference between solstice and equinox periods increases related to the upgrading geomagnetic activity. SKLD and L2N values in the solstice are larger than those in the equinox. This study is supported by TUBITAK EEEAG 114E541 a part of the Scientific and Technological Research Projects Funding Program.

  7. Clinico-immunological aspects of vernal catarrh in hilly terrains of Himachal Pradesh.

    PubMed

    Bisht, R; Goyal, A; Thakur; Singh, T; Sharma; Vijay; Goyal, B K

    1992-01-01

    Very few immunological studies in vernal catarrh have been conducted in India and abroad, but none in Himachal Pradesh in spite of its high incidence in the State. In the present study 25 patients of vernal catarrh residing at a height ranging between 1000 to 2500 meters above mean sea level have been evaluated. Their immunological status of serum and tears after detailed clinical assessment was studied by single radial immunodiffusion technique of Mancini et al. The values of serum IgA and IgM were significantly higher in patients than in controls. The serum IgE level had no significant difference. The IgG was significantly lower in patients with vernal catarrh. The values of tear IgM, IgE and IgA in these patients were significantly higher than in controls. However, in no case or control group C3C and C4 were detected in tears. The limbal type of vernal catarrh was found to be the most common in this part of the country. No mixed case was seen. Derangement of the immune system in the pathogenesis of vernal catarrh is suggested.

  8. Excimer laser phototherapeutic keratectomy for shield ulcers and corneal plaques in vernal keratoconjunctivitis.

    PubMed

    Cameron, J A; Antonios, S R; Badr, I A

    1995-01-01

    Shield-shaped corneal ulcers and corneal plaques in vernal keratoconjunctivitis are associated with delayed epithelial healing, as well as the risks of infectious keratitis and sterile stromal ulceration. Significant visual impairment due to scarring and irregular astigmatism may result from central corneal lesions. Three eyes with central corneal lesions resulting from vernal keratoconjunctivitis were treated by excimer laser after active vernal keratoconjunctivitis was controlled and inflammatory plaque overlying the shield ulcers was removed. All three eyes showed rapid reepithelialization within 1 week. Spectacle-corrected visual acuity of 20/30 or better was obtained in each eye. In selected patients, excimer laser phototherapeutic keratectomy may be a useful adjunct in the treatment of shield-shaped corneal ulcers and plaques in vernal keratoconjunctivitis.

  9. Vernalization response of domesticated× wild chickpea progeny is subject to strong genotype by environment interaction

    USDA-ARS?s Scientific Manuscript database

    Vernalization insensitivity is a key feature of domesticated chickpea and its genetic basis is not well understood. We studied vernalization response among hybrid progeny derived from two domesticated x wild crosses. The wild parents are vernalization sensitive, late flowering genotypes while both d...

  10. Science communication and vernal pool conservation: a study of local decision maker attitudes in a knowledge-action system.

    PubMed

    McGreavy, Bridie; Webler, Thomas; Calhoun, Aram J K

    2012-03-01

    In this study, we describe local decision maker attitudes towards vernal pools to inform science communication and enhance vernal pool conservation efforts. We conducted interviews with town planning board and conservation commission members (n = 9) from two towns in the State of Maine in the northeastern United States. We then mailed a questionnaire to a stratified random sample of planning board members in August and September 2007 with a response rate of 48.4% (n = 320). The majority of survey respondents favored the protection and conservation of vernal pools in their towns. Decision makers were familiar with the term "vernal pool" and demonstrated positive attitudes to vernal pools in general. General appreciation and willingness to conserve vernal pools predicted support for the 2006 revisions to the Natural Resource Protection Act regulating Significant Vernal Pools. However, 48% of respondents were unaware of this law and neither prior knowledge of the law nor workshop attendance predicted support for the vernal pool law. Further, concerns about private property rights and development restrictions predicted disagreement with the vernal pool law. We conclude that science communication must rely on specific frames of reference, be sensitive to cultural values, and occur in an iterative system to link knowledge and action in support of vernal pool conservation. Copyright © 2011 Elsevier Ltd. All rights reserved.

  11. Characteristics of Equatorial and Low-Latitude Plasma Irregularities as Investigated Using a Meridional Chain of Radio Experiments Over India

    NASA Astrophysics Data System (ADS)

    Sripathi, S.; Sreekumar, Sreeba; Banola, S.

    2018-05-01

    The characteristics of equatorial and low-latitude plasma irregularities are studied using a meridional chain of ionosondes located at Tirunelveli, Hyderabad, and Allahabad and Global Positioning System (GPS) receivers located at Tirunelveli, Mumbai, and Nagpur during the year 2015. The observations suggest that while stronger and longer duration of equatorial spread F irregularities occur in the postsunset sector during equinoxes and winter, they occur mostly in the postmidnight sector during summer, while being weaker in strength and shorter in duration. Further, the postsunset spread F occurs first at the equator followed by their occurrence at low latitudes during equinoxes and winter, while the postmidnight spread F during summer are found to be stronger and earlier at low latitudes followed by their occurrence at the equator. While plasma irregularities are observed by both the ionosondes and GPS receivers during both equinoxes and winter, it is observed mostly by the ionosondes during summer. The results further strengthen the view that while postsunset spread F in equinoxes and winter are generated by the equatorial processes, postmidnight spread F in the summer may be linked to the nonequatorial processes. The results also reemphasize the asymmetric distribution of plasma irregularities or scintillations during equinoxes wherein vernal (autumn) equinox shows more intense plasma irregularities than autumn (vernal) equinox during certain years. Also, using a larger data set of simultaneous GPS and ionosonde observations, the relationship of prereversal enhancement and strength of L-band scintillations with solar flux, Kp index, and equatorial electrojet strength are examined.

  12. Methods for estimating the amount of vernal pool habitat in the northeastern United States

    USGS Publications Warehouse

    Van Meter, R.; Bailey, L.L.; Grant, E.H.C.

    2008-01-01

    The loss of small, seasonal wetlands is a major concern for a variety of state, local, and federal organizations in the northeastern U.S. Identifying and estimating the number of vernal pools within a given region is critical to developing long-term conservation and management strategies for these unique habitats and their faunal communities. We use three probabilistic sampling methods (simple random sampling, adaptive cluster sampling, and the dual frame method) to estimate the number of vernal pools on protected, forested lands. Overall, these methods yielded similar values of vernal pool abundance for each study area, and suggest that photographic interpretation alone may grossly underestimate the number of vernal pools in forested habitats. We compare the relative efficiency of each method and discuss ways of improving precision. Acknowledging that the objectives of a study or monitoring program ultimately determine which sampling designs are most appropriate, we recommend that some type of probabilistic sampling method be applied. We view the dual-frame method as an especially useful way of combining incomplete remote sensing methods, such as aerial photograph interpretation, with a probabilistic sample of the entire area of interest to provide more robust estimates of the number of vernal pools and a more representative sample of existing vernal pool habitats.

  13. Bee diversity associated with Limnanthes floral patches in California vernal pool habitats

    Treesearch

    Joan M. Leong; Robbin W. Thorp

    2005-01-01

    As with other kinds of wetland habitats in California, approximately 90 percent of vernal pool habitat (estimated) has been lost in California. In southern California, losses are estimated to be even greater. The flora of these endangered habitats is reasonably well known, especially the spring flowering annuals that are found in or at the margins of vernal pools (for...

  14. The North South Asymmetry in Titan's Haze Through Time at Equinox

    NASA Astrophysics Data System (ADS)

    Hennen, Corbin J.; Barnes, J. W.; Lorenz, R. D.; Brown, R. H.; Sotin, C.; Buratti, B. J.; Baines, K. H.; Clark, R. N.; Nicholson, P. D.

    2013-10-01

    We use data from Cassini to observe the North South Asymmetry (NSA) in Titan's haze. We are continuing the work first addressed by the Hubble Space Telescope observations (Lorenz et al., 2004) with the Visual Infrared Mapping Spectrometer (VIMS) located on-board Cassini. Our goal is to find a quantitative description of the interhemispheric contrast, and the transition latitude between the two 'hemispheres'. These relationships could be used to improve current atmospheric models to better understand Titan weather phenomenon such as the Titan's recently-formed south polar vortex. With VIMS we are able to achieve both better spatial and spectral resolution and a better signal-to-noise ratio than previous Earth-based observations. Profiles of the asymmetry show progressive brightening of the dark northern haze relative to the south, ranging in multiple wavelengths from 351 nm (ultraviolet) to 894 nm (infrared), starting in 2005. This trend continues until Titan's northern spring equinox in August of 2009 after which Titan shifts to being north-bright relative to the south, suggesting a migration of haze to the southern hemisphere as it transitions into winter. Finally, we use a differential edge detection algorithm to isolate the latitude of the NSA boundary for each Cassini flyby, and we find a systematic migration over time.

  15. Equinoxes on Jupiter and Saturn in 2009: call for observations

    NASA Astrophysics Data System (ADS)

    Arlot, J. E.

    2008-09-01

    The equinox time on the giant planets The equinox occurs on the giant planets as on Earth, when the Sun crosses the equatorial plane i.e. every 6 years for Jupiter, 14 years for Saturn, 42 years for Uranus and 82 years for Neptune. The main large satellites of these planets have their orbits in the equatorial plane and, except Neptune, each planet have several major satellites. Note that at the time of the equinox, the Earth will also cross the equatorial plane of the planet since, as seen from the giant planets, the Earth is very close to the Sun. Then, the satellites will eclipse and occult each other mutually for a groundbased observer during a one-year period around the equinox. These events are observed with photometric receivers since the light from the satellites will decrease during the events. The light curve will provide information on the geometric configuration of the satellites at the time of the event with an accuracy of a few kilometers, not depending on the distance to Earth of the satellite system. Then, we are able to get an astrometric observation with an accuracy several times better than using direct imaging for astrometric positions. The equinox on Jupiter in 2009 The equinox on Jupiter will occur on June 22, 2009 allowing mutual events during about one year around the equinox time (mutual events will occur from January 2009 to April 2010 not regularly due to the small inclinations of the orbits of the satellites on the Jovian equator) as shown on figure n°1. observable events should be numerous. The negative declination of Jupiter will make the observations easier from southern sites but they are not sufficient as seen on figure n°5 and a special effort should be made in the northern hemisphere to make observations even when Jupiter is low above the horizon. The Galilean satellites of Jupiter are very bright (magnitude 5) and their observation is possible even with a very small telescope. Amateur astronomers are able to make such

  16. Responses of alloplasmic (cytoplasm=Triticum timopheevii) and euplasmic wheats (Triticum aestivum) to photoperiod and vernalization.

    PubMed

    Ward, R W; Heyne, E G; Paulsen, G M

    1983-07-01

    Studies were conducted to determine the influence of the male sterility-inducing cytoplasm of Triticum timopheevii (Zhuk.) Zhuk. on response of several common winter wheat (T. aestivum L.) nuclear genotypes to photoperiod and vernalization. Comparative studies of cytoplasmic substitution lines provide information on the role of the cytoplasmic genetic mechanism in growth and development. In the case of cytoplasmic male sterility-based hybrid production systems, ubiquity of sterility-inducing cytoplasm in derived hybrids warrants thorough characterization of its influence on plant phenotype. Factorial combinations of cytoplasm (T. timopheevii and T. aestivum), nuclear genotype, and photoperiod or vernalization treatments were evaluated under hydroponic conditions in controlled environment chambers. Interaction of cytoplasm, photoperiod, and nuclear genotype was significant in one or more experiments for days to anthesis and potential spikelet number, and interaction of cytoplasm, vernalization, and nuclear genotype was significant for days to spike emergence. Long day length was associated with increased percentage seed set in one study, but interactions of photoperiod and cytoplasm were not detected for percentage seed set. Interactions involving cytoplasm and photoperiod or vernalization were interpreted as evidence of the existence of genetic factors in cytoplsam of T. timopheevii which alter photoperiod or vernalization responses of alloplasmic plants relative to responses exhibited by euplasmic plants. Since photoperiod and vernalization responses are critical to adaptation, T. timopheevii cytoplasm can alter adaptability of T. aestivum. The specific effect would be nuclear genotype dependent, and does not appear to be of a magnitude greater than that induced by nuclear genetic variability at loci conditioning photoperiod or vernalization responses or other adaptation-determining characteristics. Normal multilocation/year testing of alloplasmic hybrids should

  17. Cassini-Huygens Maneuver Experience: First Year of the Equinox Mission

    NASA Technical Reports Server (NTRS)

    Gist, Emily M.; Ballard, Christopher G.; Hahn, Yungsun; Stumpf, Paul W.; Wagner, Sean V.; Williams, Powtawche N.

    2009-01-01

    The Cassini-Huygens spacecraft was launched in 1997 on a mission to observe Saturn and its many moons. After a seven-year cruise, it entered a Saturnian orbit for a four-year, prime mission. Due to the success of the prime mission, spacecraft health, and remaining propellant, a two-year extended mission, the Equinox Mission, was approved. Maneuver designs and analyses performed through the first year of the Equinox Mission are presented. Results for the 46 most recent maneuvers are given. A substantial contribution to the navigation success of the Cassini-Huygens spacecraft is the continued accurate performance, which has exceeded the pre-launch expectations and requirements.

  18. Identification of the VERNALIZATION 4 gene reveals the origin of spring growth habit in ancient wheats from South Asia

    USDA-ARS?s Scientific Manuscript database

    Wheat varieties with a winter growth habit require long exposures to low temperatures (vernalization) to accelerate flowering. Natural variation in the vernalization genes regulating this requirement has favored wheat adaptation to different environments. The main wheat vernalization genes VRN1, V...

  19. Titan's seasonal weather patterns, associated surface modification, and geological implications

    NASA Astrophysics Data System (ADS)

    Turtle, E. P.; Perry, J. E.; Barnes, J. W.; McEwen, A. S.; Barbara, J. M.; Del Genio, A. D.; Hayes, A. G.; West, R. A.; Lorenz, R. D.; Schaller, E. L.; Lunine, J. I.; Ray, T. L.; Lopes, R. M. C.; Stofan, E. R.

    2013-09-01

    Model predictions [e.g., 1-3] and observations [e.g., 4,5] illustrate changes in Titan's weather patterns related to the seasons (Fig. 1). In two cases, surface changes were documented following large cloud outbursts (Figs. 2, 3): the first in Arrakis Planitia at high southern latitudes in Fall 2004, during Titan's late southern summer [6]; and the second at lows southern latitudes in Concordia and Hetpet Regiones, Yalaing Terra (Fig. 3), and Adiri, in Fall 2010, just over a year after Titan's northern vernal equinox [4, 7, 8]. Not only do these storms demonstrate Titan's atmospheric conditions and processes, they also have important implications for Titan's surface process, its methane cycle, and its geologic history.

  20. Experimental canopy removal enhances diversity of vernal pond amphibians.

    PubMed

    Skelly, David K; Bolden, Susan R; Freidenburg, L Kealoha

    2014-03-01

    Vernal ponds are often treated as protected environments receiving special regulation and management. Within the landscapes where they are found, forest vegetation frequently dominates surrounding uplands and can grow to overtop and shade pond basins. Two bodies of research offer differing views of the role of forest canopy for vernal pond systems. Studies of landscape conversion suggest that removing forest overstory within uplands can cause local extinctions of amphibians by altering terrestrial habitat or hindering movement. Studies of canopy above pond basins imply an opposite relationship; encroachment of overstory vegetation can be associated with local extinctions potentially via changes in light, thermal, and food resource environments. Unresolved uncertainties about the role of forest canopy reveal significant gaps in our understanding of wetland species distributions and dynamics. Any misunderstanding of canopy influences is simultaneously important to managers because current practices emphasize promoting or conserving vegetation growth particularly within buffers immediately adjacent to ponds. We evaluated this apparent contradiction by conducting a landscape-scale, long-term experiment using 14 natural vernal ponds. Tree felling at six manipulated ponds was limited in spatial scope but was nevertheless effective in increasing water temperature. Compared with eight control ponds, manipulated ponds maintained more amphibian species during five years post-manipulation. There was little evidence that any species was negatively influenced, and the reproductive effort of species for which we estimated egg inputs maintained pretreatment population densities in manipulated compared with control ponds. Overall, our experiment shows that a carefully circumscribed reduction of overhead forest canopy can enhance the capacity of vernal ponds to support wildlife diversity and suggests a scale dependence of canopy influences on amphibians. These findings have

  1. HYDROLOGY AND LANDSCAPE CONNECTIVITY OF VERNAL POOLS

    EPA Science Inventory

    Vernal pools are shaped by hydrologic processes which influence many aspects of pool function. The hydrologic budget of a pool can be summarized by a water balance equation that relates changes in the amount of water in the pool to precipitation, ground- and surface-water flows, ...

  2. Life-history evolution when Lestes damselflies invaded vernal ponds.

    PubMed

    De Block, Marjan; McPeek, Mark A; Stoks, Robby

    2008-02-01

    We know little about the macroevolution of life-history traits along environmental gradients, especially with regard to the directionality compared to the ancestral states and the associated costs to other functions. Here we examine how age and size at maturity evolved when Lestes damselflies shifted from their ancestral temporary pond habitat (i.e., ponds that may dry once every decade or so) to extremely ephemeral vernal ponds (ponds that routinely dry completely each year). Larvae of three species were reared from eggs until emergence under different levels of photoperiod and transient starvation stress. Compared to the two temporary-pond Lestes, the phylogenetically derived vernal-pond Lestes dryas developed more rapidly across photoperiod treatments until the final instar, and only expressed plasticity in development time in the final instar under photoperiod levels that simulated a later hatching date. The documented change in development rate can be considered adaptive and underlies the success of the derived species in vernal ponds. Results suggest associated costs of faster development are lower mass at maturity and lower immune function after transient starvation stress. These costs may not only have impeded further evolution of the routine development rate to what is physiologically maximal, but also maintained some degree of plasticity to time constraints when the habitat shift occurred.

  3. Vernalization Requirement and the Chromosomal VRN1-Region can Affect Freezing Tolerance and Expression of Cold-Regulated Genes in Festuca pratensis

    PubMed Central

    Ergon, Åshild; Melby, Tone I.; Höglind, Mats; Rognli, Odd A.

    2016-01-01

    Plants adapted to cold winters go through annual cycles of gain followed by loss of freezing tolerance (cold acclimation and deacclimation). Warm spells during winter and early spring can cause deacclimation, and if temperatures drop, freezing damage may occur. Many plants are vernalized during winter, a process making them competent to flower in the following summer. In winter cereals, a coincidence in the timing of vernalization saturation, deacclimation, downregulation of cold-induced genes, and reduced ability to reacclimate, occurs under long photoperiods and is under control of the main regulator of vernalization requirement in cereals, VRN1, and/or closely linked gene(s). Thus, the probability of freezing damage after a warm spell may depend on both vernalization saturation and photoperiod. We investigated the role of vernalization and the VRN1-region on freezing tolerance of meadow fescue (Festuca pratensis Huds.), a perennial grass species. Two F2 populations, divergently selected for high and low vernalization requirement, were studied. Each genotype was characterized for the copy number of one of the four parental haplotypes of the VRN1-region. Clonal plants were cold acclimated for 2 weeks or vernalized/cold acclimated for a total of 9 weeks, after which the F2 populations reached different levels of vernalization saturation. Vernalized and cold acclimated plants were deacclimated for 1 week and then reacclimated for 2 weeks. All treatments were given at 8 h photoperiod. Flowering response, freezing tolerance and expression of the cold-induced genes VRN1, MADS3, CBF6, COR14B, CR7 (BLT14), LOS2, and IRI1 was measured. We found that some genotypes can lose some freezing tolerance after vernalization and a deacclimation–reacclimation cycle. The relationship between vernalization and freezing tolerance was complex. We found effects of the VRN1-region on freezing tolerance in plants cold acclimated for 2 weeks, timing of heading after 9 weeks of

  4. Certified: A Citizen's Step-by-Step Guide to Protecting Vernal Pools. 6th Edition.

    ERIC Educational Resources Information Center

    Colburn, Elizabeth A., Ed.

    The objective of this manual is to train volunteers in the process of identifying vernal pool habitat so that as many of these pools as possible can be certified by the Massachusetts Natural Heritage and Endangered Species Program. Vernal pools are a kind of temporary pond in which salamanders and other animals breed. The pools are unique…

  5. Cassini results on Titan's atmospheric and surface properties changes since the northern equinox

    NASA Astrophysics Data System (ADS)

    Coustenis, Athena; Drossart, Pierre; Flasar, F. Michael; Achterberg, Richard K.; Rodriguez, Sebastien; Nixon, Conor; Bampasidis, Georgios; Solomonidou, Anezina; Jennings, Donald; Lavvas, Panayiotis

    2016-07-01

    Since 2010, we observe the set in and enhancement at Titan's south pole of several trace species, such as HC3N and C6H6, observed only at high northern latitudes before equinox. We will present an analysis of spectra acquired by Cassini/CIRS at high resolution from 2012 in nadir mode. We investigated here several latitudes of 70°S to 70°N since 2010 (after the Southern Autumnal Equinox) until end of 2014 [1]. For some of the most abundant and longest-lived hydrocarbons (C2H2, C2H6 and C3H8) and CO2, the evolution in the past 4 years at a given latitude is not very significant within error bars especially until mid-2013 [1]. In more recent dates, these molecules show a dramatic trend for increase in the south. The 70°S and 50°S or mid-latitudes show different behavior demonstrating that they are subject to different dynamical processes in and out of the polar vortex region. For most species, we find higher abundances at 50°N compared to 50°S, with the exception of C3H8, CO2, C6H6 and HC3N, which arrive at similar mixing ratios after mid-2013 [1]. While the 70°N data show generally no change with a trend rather to a small decrease for most species within 2014, the 70°S results indicate a strong enhancement in trace stratospheric gases after 2012. In particular, HC3N, HCN and C6H6 have increased by 3 orders of magnitude over the past 3-4 years while other molecules, including C2H4, C3H4 and C4H2, have increased less sharply (by 1-2 orders of magnitude). This is a strong indication of the rapid and sudden buildup of the gaseous inventory in the southern stratosphere during 2013-2014, as expected as the pole moves deeper into winter shadow. Subsidence gases that accumulate in the absence of ultraviolet sunlight, evidently increased quickly since 2012 and some of them may be responsible also for the reported haze decrease in the north and its appearance in the south at the same time [2]. Clearly Titan is a dynamic system with indications of short and long

  6. The influence of vernalization and daylength on expression of flowering-time genes in the shoot apex and leaves of barley (Hordeum vulgare).

    PubMed Central

    Sasani, Shahryar; Hemming, Megan N.; Oliver, Sandra N.; Greenup, Aaron; Tavakkol-Afshari, Reza; Mahfoozi, Siroos; Poustini, Kazem; Sharifi, Hamid-Reza; Dennis, Elizabeth S.; Peacock, W. James; Trevaskis, Ben

    2009-01-01

    Responses to prolonged low-temperature treatment of imbibed seeds (vernalization) were examined in barley (Hordeum vulgare). These occurred in two phases: the perception of prolonged cold, which occurred gradually at low temperatures, and the acceleration of reproductive development, which occurred after vernalization. Expression of the VERNALIZATION1 gene (HvVRN1) increased gradually in germinating seedlings during vernalization, both at the shoot apex and in the developing leaves. This occurred in darkness, independently of VERNALIZATION2 (HvVRN2), consistent with the hypothesis that expression of HvVRN1 is induced by prolonged cold independently of daylength flowering-response pathways. After vernalization, expression of HvVRN1 was maintained in the shoot apex and leaves. This was associated with accelerated inflorescence initiation and with down-regulation of HvVRN2 in the leaves. The largest determinant of HvVRN1 expression levels in vernalized plants was the length of seed vernalization treatment. Daylength did not influence HvVRN1 expression levels in shoot apices and typically did not affect expression in leaves. In the leaves of plants that had experienced a saturating seed vernalization treatment, expression of HvVRN1 was higher in long days, however. HvFT1 was expressed in the leaves of these plants in long days, which might account for the elevated HvVRN1 expression. Long-day up-regulation of HvVRN1 was not required for inflorescence initiation, but might accelerate subsequent stages of inflorescence development. Similar responses to seed vernalization were also observed in wheat (Triticum aestivum). These data support the hypothesis that VRN1 is induced by cold during winter to promote spring flowering in vernalization-responsive cereals. PMID:19357429

  7. Major QTLs for critical photoperiod and vernalization underlie extensive variation in flowering in the Mimulus guttatus species complex.

    PubMed

    Friedman, Jannice; Willis, John H

    2013-07-01

    Species with extensive ranges experience highly variable environments with respect to temperature, light and soil moisture. Synchronizing the transition from vegetative to floral growth is important to employ favorable conditions for reproduction. Optimal timing of this transition might be different for semelparous annual plants and iteroparous perennial plants. We studied variation in the critical photoperiod necessary for floral induction and the requirement for a period of cold-chilling (vernalization) in 46 populations of annuals and perennials in the Mimulus guttatus species complex. We then examined critical photoperiod and vernalization QTLs in growth chambers using F(2) progeny from annual and perennial parents that differed in their requirements for flowering. We identify extensive variation in critical photoperiod, with most annual populations requiring substantially shorter day lengths to initiate flowering than perennial populations. We discover a novel type of vernalization requirement in perennial populations that is contingent on plants experiencing short days first. QTL analyses identify two large-effect QTLs which influence critical photoperiod. In two separate vernalization experiments we discover each set of crosses contain different large-effect QTLs for vernalization. Mimulus guttatus harbors extensive variation in critical photoperiod and vernalization that may be a consequence of local adaptation. © 2013 The Authors. New Phytologist © 2013 New Phytologist Trust.

  8. Depth-area-volume and hydroperiod relationships of ephemeral (vernal) forest pools in southern New England

    Treesearch

    Robert T. Brooks; Masaki Hayashi

    2002-01-01

    Ephemeral or "vernal" pools occur commonly throughout the forests of the northeastern United States and adjacent eastern Canada. These pools are critical breeding habitat for a number of amphibian species and support a diverse invertebrate community. The hydroperiod or duration of surface water of vernal pools affects faunal composition and reproduction. We...

  9. Shrew species richness and abundance in relation to vernal pond habitat in southern New England

    Treesearch

    Robert T. Brooks; Katherine L. Doyle

    2001-01-01

    Vernal ponds are important aquatic habitat for many species of amphibians and invertebrates. While many aspects of such ponds have been investigated, small mammal populations in the adjacent upland [catchment] habitat are largely unstudied. We selected three ponds in central Massachusetts to determine whether the presence of vernal ponds in forested habitat influences...

  10. Shield ulcers and plaques of the cornea in vernal keratoconjunctivitis.

    PubMed

    Cameron, J A

    1995-06-01

    Shield-shaped corneal ulcers and plaques are serious sight-threatening corneal manifestations of vernal keratoconjunctivitis. There are few reports describing the management of these patients and their outcomes. The clinical presentation, treatment, and outcome of 66 shield ulcers and/or plaques in 55 eyes of 41 patients with vernal keratoconjunctivitis were studied in this retrospective study of patients treated at King Khaled Eye Specialist Hospital during an 11-year period. Patients with shield ulcers where the base of the ulcer was transparent usually had rapid re-epithelialization and an excellent visual outcome with medical treatment alone. Patients with shield ulcers and visible plaque formation had delayed re-epithelialization when receiving only medical treatment. Complications of delayed re-epithelialization consisted of bacterial keratitis in five eyes, amblyopia in one eye, and strabismus in one patient. Patients with shield ulcers and/or plaques that do not re-epithelialize once active vernal keratoconjunctivitis has been controlled should have surgical intervention. In this series, a simple scraping of the base and margins of the ulcer with removal of the inflammatory material (i.e., the plaque) resulted in rapid re-epithelialization in 20 of 23 ulcers and plaques. An algorithm for treating shield ulcers and/or plaques is presented based on the experience at this institution.

  11. Education and public outreach during the spring equinox, 2012

    NASA Astrophysics Data System (ADS)

    Zueck, S. L.; Lara, A.

    2012-12-01

    We organized for third occasion a solar physics activities during the spring equinox of 2012. On March 20 a group of researchers and their graduate students, amateur astronomers and educators all of them members of the Universidad Nacional Autónoma de México (UNAM) went to a beautiful village named Tepoztlan, Morelos, located 30 minutes from the City and Mexico. We give lectures and install solar telescopes in the garden of the former convent of Tepoztlan near a mountain considered sacred. During the equinox day the mountain is climbed by thousands of individuals to catch solar energy that they consider vital, specially during a year that many of them consider the end of a era. Through media and advertisements we invite visitors to our free event. We expected to hear different assumptions about our closest star, the Sun, and interact with different socio-cultural views at the same time that we presented our concepts of science in a every day language.

  12. Ionospheric responses during equinox and solstice periods over Turkey

    NASA Astrophysics Data System (ADS)

    Karatay, Secil; Cinar, Ali; Arikan, Feza

    2017-11-01

    Ionospheric electron density is the determining variable for investigation of the spatial and temporal variations in the ionosphere. Total Electron Content (TEC) is the integral of the electron density along a ray path that indicates the total variability through the ionosphere. Global Positioning System (GPS) recordings can be utilized to estimate the TEC, thus GPS proves itself as a useful tool in monitoring the total variability of electron distribution within the ionosphere. This study focuses on the analysis of the variations of ionosphere over Turkey that can be grouped into anomalies during equinox and solstice periods using TEC estimates obtained by a regional GPS network. It is observed that noon time depletions in TEC distributions predominantly occur in winter for minimum Sun Spots Numbers (SSN) in the central regions of Turkey which also exhibit high variability due to midlatitude winter anomaly. TEC values and ionospheric variations at solstice periods demonstrate significant enhancements compared to those at equinox periods.

  13. ODDSOC2 Is a MADS Box Floral Repressor That Is Down-Regulated by Vernalization in Temperate Cereals1[W][OA

    PubMed Central

    Greenup, Aaron G.; Sasani, Shahryar; Oliver, Sandra N.; Talbot, Mark J.; Dennis, Elizabeth S.; Hemming, Megan N.; Trevaskis, Ben

    2010-01-01

    In temperate cereals, such as wheat (Triticum aestivum) and barley (Hordeum vulgare), the transition to reproductive development can be accelerated by prolonged exposure to cold (vernalization). We examined the role of the grass-specific MADS box gene ODDSOC2 (OS2) in the vernalization response in cereals. The barley OS2 gene (HvOS2) is expressed in leaves and shoot apices but is repressed by vernalization. Vernalization represses OS2 independently of VERNALIZATION1 (VRN1) in a VRN1 deletion mutant of einkorn wheat (Triticum monococcum), but VRN1 is required to maintain down-regulation of OS2 in vernalized plants. Furthermore, barleys that carry active alleles of the VRN1 gene (HvVRN1) have reduced expression of HvOS2, suggesting that HvVRN1 down-regulates HvOS2 during development. Overexpression of HvOS2 delayed flowering and reduced spike, stem, and leaf length in transgenic barley plants. Plants overexpressing HvOS2 showed reduced expression of barley homologs of the Arabidopsis (Arabidopsis thaliana) gene FLOWERING PROMOTING FACTOR1 (FPF1) and increased expression of RNase-S-like genes. FPF1 promotes floral development and enhances cell elongation, so down-regulation of FPF1-like genes might explain the phenotypes of HvOS2 overexpression lines. We present an extended model of the genetic pathways controlling vernalization-induced flowering in cereals, which describes the regulatory relationships between VRN1, OS2, and FPF1-like genes. Overall, these findings highlight differences and similarities between the vernalization responses of temperate cereals and the model plant Arabidopsis. PMID:20431086

  14. Seeing Equinoxes and Solstices from Space

    NASA Image and Video Library

    2014-03-19

    Images acquired December 21, 2010 - September 20, 2011. To view a HD animation of this go to: www.flickr.com/photos/gsfc/6175313242/in/photostream/ To download the high res and learn more go to: earthobservatory.nasa.gov/IOTD/view.php?id=52248 One of the most frequently misunderstood concepts in science is the reason for Earth’s seasons. As we experience the September equinox today—anyone try to balance an egg yet?—we thought we’d offer a space-based view of what’s going on. Around 6 a.m. local time each day, the Sun, Earth, and any geosynchronous satellite form a right angle, affording a nadir (straight down) view of the terminator, where the shadows of nightfall meet the sunlight of dusk and dawn. The shape of this line between night and day varies with the seasons, which means different lengths of days and differing amounts of warming sunshine. (The line is actually a curve because the Earth is round, but satellite images only show it in two-dimensions.) The Spinning Enhanced Visible and Infrared Imager (SEVIRI) on EUMETSAT's Meteosat-9 captured these four views of the day-night terminator on December 21, 2010, and March 20, June 21, and September 20, 2011. Each image was taken at 6:12 a.m. local time. On March 20 and September 20, the terminator is a straight north-south line, and the Sun is said to sit directly above the equator. On December 21, the Sun resides directly over the Tropic of Capricorn when viewed from the ground, and sunlight spreads over more of the Southern Hemisphere. On June 21, the Sun sits above the Tropic of Cancer, spreading more sunlight in the north and turning the tables on the south. The bulge of our spherical Earth blocks sunlight from the far hemisphere at the solstices; that same curvature allows the Sun’s rays to spread over more area near the top and bottom of the globe. Of course, it is not the Sun that is moving north or south through the seasons, but a change in the orientation and angles between the Earth and its

  15. Uranus' post-equinox north polar brightening characterized with 2013 and 2016 IRTF SpeX observation

    NASA Astrophysics Data System (ADS)

    Fry, Patrick M.; Sromovsky, Lawrence A.

    2017-10-01

    Since its 2007 equinox, the atmosphere of Uranus, as seen in the near infrared (~800-1600 nm) has exhibited dramatic changes. Its southern polar cap, prominent prior to equinox, has faded and a similar polar cap has begun developing in the north. Karkoschka and Tomasko (2009, Icarus 202:287) demonstrated that in 2002 the south polar region, brighter than lower latitude regions when viewed at wavelengths of intermediate methane absorption, was depleted in methane compared to darker regions. Tice et al. (2013, Icarus 223:684) and Sromovsky et al. (2014, Icarus 238:137) concluded that the northern polar regions were similarly depleted. The north polar region (45N-90N) has continued to brighten; modeling of 2015 HST STIS observations (Fry et al. 2016, AAS DPS #48 421.03) suggested that the latitudinal methane distribution has remained essentially unchanged since equinox, but brightening from 2012 to 2015 was due to changes in aerosol scattering. We acquired 0.8-2.5 μm SpeX spectra in 2013 (central meridian) and 2016 (pole-aligned spectra at 0, 0.4, 0.8, and 1.2 arcsec. distant from the CM) under similar seeing conditions (0.4-0.5 arcsec.). The SpeX wavelength range gives us an additional wavelength region where H2 absorption competes with or exceeds CH4 absorption, and a wider wavelength range to characterize aerosol particle properties, compared to STIS. The multiple spectra in 2016 allow us to compare specific latitudes to 2013 at the same view angles (and to use center-to-limb constraints in modeling 2016 spectra). We will present observations, reduction procedures, comparative (2013 vs 2016) modeling of latitudinal methane abundance and vertical aerosol profiles, and compare to 2012/2015 STIS analysis. Preliminary analysis shows that lower latitudes (~30N) have not changed since 2013, but higher latitudes (~70N) have undergone continued significant brightening at pseudo-continuum wavelengths dominated by both H2 (1080 nm, up ~50%) and CH4 (1290 nm, also up ~50

  16. Implications for Nucleus Heterogeneity from the Comparison of Pre- and Post-Equinox Neutral ROSINA Observations Inbound and Outbound Beyond 3 AU

    NASA Astrophysics Data System (ADS)

    Luspay-Kuti, A.; Altwegg, K.; Berthelier, J. J.; Beth, A.; Dhooghe, F.; Fiethe, B.; Fuselier, S. A.; Gombosi, T. I.; Hansen, K. C.; Hässig, M.; Mall, U.; Mandt, K.; Mousis, O.; Steven, P. M.; Rubin, M.; Trattner, K. J.; Tzou, C. Y.; Wurz, P.

    2017-12-01

    Pre-equinox ROSINA/DFMS measurements revealed a strongly heterogeneous coma. The concentrations of major and various minor volatile species were found to depend on the latitude and longitude of the nadir point of the spacecraft. The observed time variability of coma species remained consistent for about three months up to equinox. The chemical variability could be generally interpreted in terms of temperature and seasonal effects superposed on some kind of nucleus heterogeneity. We compare here pre-equinox (inbound) ROSINA/DFMS measurements from 2014 to measurements taken after the outbound equinox in 2016, both at heliocentric distances larger than 3 AU. For a direct comparison we limit our observations to the southern, poorly illuminated hemisphere only. We report the similarities and differences in the concentrations and time variability of neutral species under similar insolation conditions (heliocentric distance, season) pre- and post-equinox, and interpret them in light of the pre-equinox observations. Such direct comparison of the neutral behavior is important to better understand the evolution of cometary outgassing.

  17. An Effective Method for Detecting Potential Woodland Vernal Pools Using High-Resolution LiDAR Data and Aerial Imagery

    EPA Science Inventory

    Effective conservation of woodland vernal pools – important components of regional amphibian diversity and ecosystem services – depends on locating and mapping these pools accurately. Current methods for identifying potential vernal pools are primarily based on visual interpretat...

  18. A Mathematical Description of the PULSAR Doppler Satellite Tracking Data Editor.

    DTIC Science & Technology

    1982-09-01

    D .2.2 Position Derivatives of the Atmospheric Drag Acceleration:9r (con’t) v ( X r (i 1,2,3) (29) j=1’ k=1 re c. is the Levi - Civita density defined...obliquity of the ecliptic. The ecliptic intersects the celestial equator at two points called the vernal equinox and the autumnal equinox, i.e. the...direction to the earth’s rotation and has a period of approximately 26,000 years. , This conical motion is usually treated as the sum of two components

  19. The Equinox Transition Study - An overview. [thermosphere/ionosphere dynamics

    NASA Technical Reports Server (NTRS)

    Carlson, H. C., Jr.; Crowley, G.

    1989-01-01

    An overview is presented of the Equinox Transition Study (ETS), including the historical perspective, the experimental philosophy, and the results of the analysis. The broad scientific aim of ETS is to understand the electromechanical response of the thermosphere/ionosphere system to variable high-latitude forcing. Some of the results obtained from ETS are summarized.

  20. Glyma11g13220, a homolog of the vernalization pathway gene VERNALIZATION 1 from soybean [Glycine max (L.) Merr.], promotes flowering in Arabidopsis thaliana.

    PubMed

    Lü, Jing; Suo, Haicui; Yi, Rong; Ma, Qibin; Nian, Hai

    2015-09-29

    The precise timing of flowering is fundamental to successful reproduction, and has dramatic significance for crop yields. Although prolonged low temperatures are not required for flowering induction in soybean, vernalization pathway genes have been retained during the evolution of this species. Little information is currently available in regarding these genes in soybean. We were able to detect the expression of Glyma11g13220 in different organs at all monitored developmental stages in soybean. Glyma11g13220 expression was higher in leaves and pods than in shoot apexes and stems. In addition, Glyma11g13220 was responsive to photoperiod and low temperature in soybean. Furthermore, Glyma11g13220 was found to be a nuclear-localized protein. Over-expression of Glyma11g13220 in an Arabidopsis Columbia-0 (Col-0) background resulted in early flowering. Quantitative real-time PCR analysis revealed that transcript levels of flower repressor FLOWERING LOCUS C (FLC), and FD decreased significantly in transgenic Arabidopsis compared with wild-type Col-0, while the expression of VERNALIZATION INSENSITIVE 3 (VIN3) and FLOWERING LOCUS T (FT) noticeably increased. Our results suggest that Glyma11g13220, a homolog of Arabidopsis VRN1, is a functional protein. Glyma11g13220, which is responsive to photoperiod and low temperature in soybean, may participate in the vernalization pathway in Arabidopsis and help regulate flowering time. Arabidopsis VRN1 and Glyma11g13220 exhibit conserved as well as diverged functions.

  1. Vernal Crater, SW Arabia Terra: MSL Candidate with Extensively Layered Sediments, Possible Lake Deposits, and a Long History of Subsurface Ice

    NASA Technical Reports Server (NTRS)

    Oehler, Dorothy Z.; Allen, Carlton C.

    2007-01-01

    Vernal Crater is a Mars Science Laboratory (MSL) landing site candidate providing relatively easy access to extensively layered sediments as well as potential lake deposits. Sediments of Vernal Crater are 400-1200 m below those being investigated by Opportunity in Meridiani Planum, and as such would allow study of significantly older geologic units, if Vernal Crater were selected for MSL. The location of Vernal Crater in SW Arabia Terra provides exceptional scientific interest, as rampart craters and gamma-ray spectrometer (GRS) data from the region suggest a long history of ice/fluids in the subsurface. The potential value of this MSL candidate is further enhanced by reports of atmospheric methane over Arabia, as any insight into the source of that methane would significantly increase our understanding of Mars. Finally, should MSL survive beyond its prime mission, the gentle slope within Vernal Crater would provide a route out of the crater for study of the once ice/fluid-rich plains.

  2. Assessing the Occurrence, Persistence, and Fate of Natural and Synthetic Steroid Estrogens in Vernal Pools

    NASA Astrophysics Data System (ADS)

    Mina, O.

    2015-12-01

    The presence of natural and synthetic estrogens in treated wastewater used for irrigation of agricultural fields poses a potential risk to surface water ecosystems. While a large number of recent studies have investigated the occurrence, fate, and transport of estrogens in the environment, the vast majority of these studies have focused on the fate of estrogens in streams and rivers. However, no studies have been conducted assessing the occurrence, persistence, and fate of estrogens in impacted sensitive aquatic ecosystems such as vernal pools. This is of particular importance because vernal pools serve as critical breeding habitat for amphibians, which are known to be sensitive to the presence of endocrine disrupting compounds. A spray irrigation system was implemented over 50 years ago at Penn State's "Living Filter" as an alternative to discharging treated wastewater to a high quality trout stream. This system introduces all of Penn State's treated wastewater onto approximately 250 ha of agricultural and forested land at a rate of ~5 cm/ha/week. More than a dozen vernal pools are impacted by this wastewater irrigation, with some ponds adjacent to irrigation laterals receiving direct inputs of the treated wastewater. The goal of this study was to assess the impact of these weekly irrigation activities on the occurrence, persistence, and fate of estrogens (17α- and 17β-estradiol, estrone, estriol, and ethinylestradiol) in 3 vernal pools during an 8-week field study. The spring 2015 study period coincided with wood frog breeding and metamorphosis. Irrigation wastewater was collected weekly and water samples near the sediment-water interface in each vernal pool were collected daily. Real-time monitoring stations continuously recorded the temperature, pH, redox potential, DO, EC, and water level at each pool. Nearly 100% of the daily samples (n>130) collected contained estrogens, and the concentrations were several times higher compared to the wastewater

  3. Heading date QTL in winter wheat (Triticum aestivum L.) coincide with major developmental genes Vernalization-1 and Photoperiod-1

    USDA-ARS?s Scientific Manuscript database

    In wheat (Triticum aestivum L.), time from planting to spike emergence is influenced by genes controlling vernalization requirement and photoperiod response. Characterizing the available genetic diversity of known and novel alleles of Vernalization-1 (Vrn-1) and Photoperiod-1 (Ppd-1) in winter wheat...

  4. A seasonal study on the role of h'F/meridional winds in influencing the development of ESF irregularities over Indian sector

    NASA Astrophysics Data System (ADS)

    Sreekumar, Sreeba; Sripathi, S.

    2017-08-01

    In this paper, we present the seasonal variation of nighttime thermospheric meridional winds over Hyderabad as derived using dual ionosonde observations located at Tirunelveli (8.7°N, 77.7°E, Dip Lat = 0.3°N), an equatorial station and Hyderabad (17.38°N, 78.45°E, Dip Lat = 12°N), a low latitude station, respectively, over the period of April-December 2013 using h'F data as discussed in (Sreekumar and Sripathi, 2016). The calculated winds has been compared with HWM14 wind model. The results show that trends of the derived winds from the ionosonde h'F data matches well with model wind near to midnight hours in all the seasons. However, some dissimilarities were observed during early night hours. Especially, the poleward winds during early night hours for different seasons were not well reproduced by the model. Later, the study is extended to understand the role of meridional winds in causing the variability of ESF occurrence vis a vis h'F. The histogram analysis of h'F vs wind values just before ESF onset reveals that the most probable combination of wind and h'F on the ESF days are centered around 350 km and 50 m/s. Additionally, we also performed Superposed Epoch Analysis (SEA) based on longer and shorter duration ESF events. The analysis reveals the distinct differences in the longer and shorter duration ESF events of Summer and Autumn equinox where the values of h'F as well as meridional winds where such that a steep change in reduction of poleward winds prior to ESF onset supported the longer duration ESF events in both seasons. However, this steep reduction is not so significant for the shorter duration ESF events indicating that meridional winds could play a crucial role in extending the spread F durations in longer duration events. The observations clearly demonstrate the reduction of poleward wind velocities during vernal equinox as compared to Autumn equinox, where larger poleward winds were present around ESF onset times. These observations are

  5. Vernal freeze damage and genetic variation alter tree growth, chemistry, and insect interactions.

    PubMed

    Rubert-Nason, Kennedy F; Couture, John J; Gryzmala, Elizabeth A; Townsend, Philip A; Lindroth, Richard L

    2017-11-01

    Anticipated consequences of climate change in temperate regions include early spring warmup punctuated by intermittent hard freezes. Warm weather accelerates leaf flush in perennial woody species, potentially exposing vulnerable young tissues to damaging frosts. We employed a 2 × 6 randomized factorial design to examine how the interplay of vernal (springtime) freeze damage and genetic variation in a hardwood species (Populus tremuloides) influences tree growth, phytochemistry, and interactions with an insect herbivore (Chaitophorus stevensis). Acute effects of freezing included defoliation and mortality. Surviving trees exhibited reduced growth and altered biomass distribution. Reflushed leaves on these trees had lower mass per area, lower lignin concentrations, and higher nitrogen concentrations, altered chemical defence profiles, and supported faster aphid population growth. Many effects varied among plant genotypes and were related with herbivore performance. This study suggests that a single damaging vernal freeze event can alter tree-insect interactions through effects on plant growth and chemistry. Differential responses of various genotypes to freeze damage suggest that more frequent vernal freeze events could also influence natural selection, favouring trees with greater freeze hardiness, and more resistance or tolerance to herbivores following damage. © 2017 John Wiley & Sons Ltd.

  6. Vernalizing cold is registered digitally at FLC.

    PubMed

    Angel, Andrew; Song, Jie; Yang, Hongchun; Questa, Julia I; Dean, Caroline; Howard, Martin

    2015-03-31

    A fundamental property of many organisms is an ability to sense, evaluate, and respond to environmental signals. In some situations, generation of an appropriate response requires long-term information storage. A classic example is vernalization, where plants quantitatively sense long-term cold and epigenetically store this cold-exposure information to regulate flowering time. In Arabidopsis thaliana, stable epigenetic memory of cold is digital: following long-term cold exposure, cells respond autonomously in an all-or-nothing fashion, with the fraction of cells that stably silence the floral repressor flowering locus C (FLC) increasing with the cold exposure duration. However, during cold exposure itself it is unknown whether vernalizing cold is registered at FLC in individual cells in an all-or-nothing (digital) manner or is continuously varying (analog). Using mathematical modeling, we found that analog registration of cold temperature is problematic due to impaired analog-to-digital conversion into stable memory. This disadvantage is particularly acute when responding to short cold periods, but is absent when cold temperatures are registered digitally at FLC. We tested this prediction experimentally, exposing plants to short periods of cold interrupted with even shorter warm breaks. For FLC expression, we found that the system responds similarly to both interrupted and uninterrupted cold, arguing for a digital mechanism integrating long-term temperature exposure.

  7. Vernalizing cold is registered digitally at FLC

    PubMed Central

    Angel, Andrew; Song, Jie; Yang, Hongchun; Questa, Julia I.; Dean, Caroline; Howard, Martin

    2015-01-01

    A fundamental property of many organisms is an ability to sense, evaluate, and respond to environmental signals. In some situations, generation of an appropriate response requires long-term information storage. A classic example is vernalization, where plants quantitatively sense long-term cold and epigenetically store this cold-exposure information to regulate flowering time. In Arabidopsis thaliana, stable epigenetic memory of cold is digital: following long-term cold exposure, cells respond autonomously in an all-or-nothing fashion, with the fraction of cells that stably silence the floral repressor FLOWERING LOCUS C (FLC) increasing with the cold exposure duration. However, during cold exposure itself it is unknown whether vernalizing cold is registered at FLC in individual cells in an all-or-nothing (digital) manner or is continuously varying (analog). Using mathematical modeling, we found that analog registration of cold temperature is problematic due to impaired analog-to-digital conversion into stable memory. This disadvantage is particularly acute when responding to short cold periods, but is absent when cold temperatures are registered digitally at FLC. We tested this prediction experimentally, exposing plants to short periods of cold interrupted with even shorter warm breaks. For FLC expression, we found that the system responds similarly to both interrupted and uninterrupted cold, arguing for a digital mechanism integrating long-term temperature exposure. PMID:25775579

  8. Orientation of the JPL Ephemerides, DE 200/LE 200, to the dynamical equinox of J 2000

    NASA Technical Reports Server (NTRS)

    Standish, E. M., Jr.

    1982-01-01

    The lunar and planetary ephemerides, DE 200/LE 200 have been recently produced at JPL. They will form the basis of the ephemerides in the 'Astronomical Almanac' starting in the year 1984. The origin has been referenced to the J 2000 dynamical equinox of the ephemerides themselves. The procedure for this orientation is described here in detail. Analyses of the ephemerides also provide comparisons with the equinox of the FK 4 and with presently adopted values for the earth's obliquity.

  9. Cassini Maneuver Experience: Ending the Equinox Mission

    NASA Technical Reports Server (NTRS)

    Ballard, Christopher G.; Arrieta, Juan; Hahn, Yungsun; Stumpf, Paul W.; Wagner, Sean V.; Williams, Powtawche N.

    2010-01-01

    The Cassini-Huygens spacecraft was launched in 1997 on a mission to observe Saturn and its many moons. After a seven-year interplanetary cruise, it entered a Saturnian orbit for a four-year Prime Mission in 2004 and began a two-year Equinox Mission in 2008. It has been approved for another seven-year mission, the Solstice Mission, starting in October 2010. This paper highlights significant maneuver activities performed from July 2009 to June 2010. We present results for the 45 maneuvers during this time. The successful navigation of the Cassini orbiter can be attributed in part to the accurate maneuver performance, which has greatly exceeded pre-launch expectations.

  10. Seeing Equinoxes and Solstices from Space [hd animation

    NASA Image and Video Library

    2014-03-19

    Images acquired December 21, 2010 - September 20, 2011. To download the high res and learn more go to: earthobservatory.nasa.gov/IOTD/view.php?id=52248 One of the most frequently misunderstood concepts in science is the reason for Earth’s seasons. As we experience the September equinox today—anyone try to balance an egg yet?—we thought we’d offer a space-based view of what’s going on. Around 6 a.m. local time each day, the Sun, Earth, and any geosynchronous satellite form a right angle, affording a nadir (straight down) view of the terminator, where the shadows of nightfall meet the sunlight of dusk and dawn. The shape of this line between night and day varies with the seasons, which means different lengths of days and differing amounts of warming sunshine. (The line is actually a curve because the Earth is round, but satellite images only show it in two-dimensions.) The Spinning Enhanced Visible and Infrared Imager (SEVIRI) on EUMETSAT's Meteosat-9 captured these four views of the day-night terminator on December 21, 2010, and March 20, June 21, and September 20, 2011. Each image was taken at 6:12 a.m. local time. On March 20 and September 20, the terminator is a straight north-south line, and the Sun is said to sit directly above the equator. On December 21, the Sun resides directly over the Tropic of Capricorn when viewed from the ground, and sunlight spreads over more of the Southern Hemisphere. On June 21, the Sun sits above the Tropic of Cancer, spreading more sunlight in the north and turning the tables on the south. The bulge of our spherical Earth blocks sunlight from the far hemisphere at the solstices; that same curvature allows the Sun’s rays to spread over more area near the top and bottom of the globe. Of course, it is not the Sun that is moving north or south through the seasons, but a change in the orientation and angles between the Earth and its nearest star. The axis of the Earth is tilted 23.5 degrees relative to the Sun and the

  11. The Maine Vernal Pool Mapping and Assessment Program: Engaging Municipal Officials and Private Landowners in Community-Based Citizen Science

    NASA Astrophysics Data System (ADS)

    Jansujwicz, Jessica S.; Calhoun, Aram J. K.; Lilieholm, Robert J.

    2013-12-01

    The Vernal Pool Mapping and Assessment Program (VPMAP) was initiated in 2007 to create a vernal pool database as a planning tool to foster local compliance with new state vernal pool regulations. In the northeastern United States, vernal pools are seasonal wetlands that provide critical breeding habitat for a number of amphibians and invertebrates and provide important resting and foraging habitat for some rare and endangered state-listed species. Using participant observation, interviews, and focus groups, we examined the engagement of municipal officials and private landowners in VPMAP. Important outcomes of municipal and landowner engagement included mobilization of town support for proactive planning, improved awareness and understanding of vernal pools, and increased interactions between program coordinators, municipal officials, and private landowners. Challenges to municipal and landowner engagement included an inconsistency in expectations between coordinators and municipal officials and a lack of time and sufficient information for follow-up with landowners participating in VPMAP. Our study highlights the importance of developing relationships among coordinators, municipal officials, and private landowners in facilitating positive outcomes for all stakeholders and for effective resource management. We suggest an expanded citizen science model that focuses on improving two-way communication among project coordinators, municipal officials, and local citizens and places communication with private landowners on par with volunteer citizen scientist recruitment and field training. Lessons learned from this research can inform the design and implementation of citizen science projects on private land.

  12. Lunar ephemeris selenographic coordinates of the earth and sun for 1975 and 1976

    NASA Technical Reports Server (NTRS)

    Hartung, A. D.

    1972-01-01

    Ephemeris data are presented for 1975 and 1976 to provide a time history of lunar coordinates and related geometric information. A Manned Spacecraft Center modification of the Jet Propulsion Laboratory ephemeris tape was used to calculate and plot coordinates of the earth, moon, and sun. The ephemeris is referenced to the mean vernal equinox at the nearest beginning of a Besselian year. Therefore the reference equinox changes from one year to the next between 30 June and 1 July. The apparent discontinuity in the data is not noticeable in the graphical presentation, but can be observed in the digital output. The mean equator of epoch is used in all cases.

  13. A longer vernal window: the role of winter coldness and snowpack in driving spring transitions and lags.

    PubMed

    Contosta, Alexandra R; Adolph, Alden; Burchsted, Denise; Burakowski, Elizabeth; Green, Mark; Guerra, David; Albert, Mary; Dibb, Jack; Martin, Mary; McDowell, William H; Routhier, Michael; Wake, Cameron; Whitaker, Rachel; Wollheim, Wilfred

    2017-04-01

    Climate change is altering the timing and duration of the vernal window, a period that marks the end of winter and the start of the growing season when rapid transitions in ecosystem energy, water, nutrient, and carbon dynamics take place. Research on this period typically captures only a portion of the ecosystem in transition and focuses largely on the dates by which the system wakes up. Previous work has not addressed lags between transitions that represent delays in energy, water, nutrient, and carbon flows. The objectives of this study were to establish the sequence of physical and biogeochemical transitions and lags during the vernal window period and to understand how climate change may alter them. We synthesized observations from a statewide sensor network in New Hampshire, USA, that concurrently monitored climate, snow, soils, and streams over a three-year period and supplemented these observations with climate reanalysis data, snow data assimilation model output, and satellite spectral data. We found that some of the transitions that occurred within the vernal window were sequential, with air temperatures warming prior to snow melt, which preceded forest canopy closure. Other transitions were simultaneous with one another and had zero-length lags, such as snowpack disappearance, rapid soil warming, and peak stream discharge. We modeled lags as a function of both winter coldness and snow depth, both of which are expected to decline with climate change. Warmer winters with less snow resulted in longer lags and a more protracted vernal window. This lengthening of individual lags and of the entire vernal window carries important consequences for the thermodynamics and biogeochemistry of ecosystems, both during the winter-to-spring transition and throughout the rest of the year. © 2016 The Authors Global Change Biology Published by John Wiley & Sons Ltd.

  14. Seasonal variations of the ionospheric total electron content in Asian equatorial anomaly regions

    NASA Astrophysics Data System (ADS)

    Tsai, Ho-Fang; Liu, Jann-Yenq; Tsai, Wei-Hsiung; Liu, Chao-Han; Tseng, Ching-Liang; Wu, Chin-Chun

    2001-12-01

    The ionospheric total electron contents (TEC) in both northern and southern equatorial anomaly regions are examined by using the Global Positioning System (GPS) in Asian area. The TEC contour charts obtained at YMSM (25.2°N, 121.6°E 14.0°N geomagnetic) and DGAR (7.3°S, 72.4°E 16.2°S geomagnetic) stations in 1997, solar minimum, are investigated. It is found that the ionospheric crests manifest remarkable seasonal variations. The TEC values on both northern and southern equatorial anomaly crests yield their maximum values during the vernal and autumnal months, but the winter anomaly does not appear in the southern region. Results show that both crests are fully developed around midday in winter, postnoon in equinoxes and late afternoon in summer, and the two crests move significantly equatorward in winter but slightly poleward in summer and autumn. These phenomena can be fully explained by a combined theory of the transequatorial neutral wind, the subsolar point, and the auroral equatorward wind.

  15. Livestock Grazing as a Driver of Vernal Pool Ecohydrology

    NASA Astrophysics Data System (ADS)

    Michaels, J.; McCarten, N. F.

    2017-12-01

    Vernal pools are seasonal wetlands that host rare plant communities of high conservation priority. Plant community composition is largely driven by pool hydroperiod. A previous study found that vernal pools grazed by livestock had longer hydroperiods compared with pools excluded from grazing for 10 years, and suggests that livestock grazing can be used to protect plant diversity. It is important to assess whether observed differences are due to the grazing or due to water balance variables including upland discharge into or out of the pools since no a priori measurements were made of the hydrology prior to grazing. To address this question, in 2016 we compared 15 pools that have been grazed continuously and 15 pools that have been fenced off for over 40 years at a site in Sacramento County. We paired pools based on abiotic characteristics (size, shape, slope, soil type) to minimize natural variation. We sampled vegetation and water depth using Solinst level loggers. We found that plant diversity and average hydroperiod was significantly higher in the grazed pools. We are currently measuring groundwater connectivity and upland inputs in order to compare the relative strength of livestock grazing as a driver of hydroperiod to these other drivers.

  16. Grazing impacts on infiltration rates at Vernal Pools in the Modoc Plateau

    USDA-ARS?s Scientific Manuscript database

    Vernal pools are depressions of land that are seasonally inundated with water. They host rare and endemic plant and animal species and are sensitive to livestock grazing management and climate change impacts on hydrology and vegetation. Climate change forecasts predicting a hotter, drier climate sug...

  17. Comprehensive transcriptome analysis reveals distinct regulatory programs during vernalization and floral bud development of orchardgrass (Dactylis glomerata L.).

    PubMed

    Feng, Guangyan; Huang, Linkai; Li, Ji; Wang, Jianping; Xu, Lei; Pan, Ling; Zhao, Xinxin; Wang, Xia; Huang, Ting; Zhang, Xinquan

    2017-11-22

    Vernalization and the transition from vegetative to reproductive growth involve multiple pathways, vital for controlling floral organ formation and flowering time. However, little transcription information is available about the mechanisms behind environmental adaption and growth regulation. Here, we used high-throughput sequencing to analyze the comprehensive transcriptome of Dactylis glomerata L. during six different growth periods. During vernalization, 4689 differentially expressed genes (DEGs) significantly increased in abundance, while 3841 decreased. Furthermore, 12,967 DEGs were identified during booting stage and flowering stage, including 7750 up-regulated and 5219 down-regulated DEGs. Pathway analysis indicated that transcripts related to circadian rhythm, photoperiod, photosynthesis, flavonoid biosynthesis, starch, and sucrose metabolism changed significantly at different stages. Coexpression and weighted correlation network analysis (WGCNA) analysis linked different stages to transcriptional changes and provided evidence of inner relation modules associated with signal transduction, stress responses, cell division, and hormonal transport. We found enrichment in transcription factors (TFs) related to WRKY, NAC, AP2/EREBP, AUX/IAA, MADS-BOX, ABI3/VP1, bHLH, and the CCAAT family during vernalization and floral bud development. TFs expression patterns revealed intricate temporal variations, suggesting relatively separate regulatory programs of TF modules. Further study will unlock insights into the ability of the circadian rhythm and photoperiod to regulate vernalization and flowering time in perennial grass.

  18. Regulation of vernal migration in Gambel's white-crowned sparrows: Role of thyroxine and triiodothyronine.

    PubMed

    Pérez, Jonathan H; Furlow, J David; Wingfield, John C; Ramenofsky, Marilyn

    2016-08-01

    Appropriate timing of migratory behavior is critical for migrant species. For many temperate zone birds in the spring, lengthening photoperiod is the initial cue leading to morphological, physiological and behavior changes that are necessary for vernal migration and breeding. Strong evidence has emerged in recent years linking thyroid hormone signaling to the photoinduction of breeding in birds while more limited information suggest a potential role in the regulation of vernal migration in photoperiodic songbirds. Here we investigate the development and expression of the vernal migratory life history stage in captive Gambel's white-crowned sparrows (Zonotrichia leucophrys gambelii) in a hypothyroidic state, induced by chemical inhibition of thyroid hormone production. To explore possible variations in the effects of the two thyroid hormones, triiodothyronine and thyroxine, we subsequently performed a thyroid inhibition coupled with replacement therapy. We found that chemical inhibition of thyroid hormones resulted in complete abolishment of mass gain, fattening, and muscle hypertrophy associated with migratory preparation as well as resulting in failure to display nocturnal restlessness behavior. Replacement of thyroxine rescued all of these elements to near control levels while triiodothyronine replacement displayed partial or delayed rescue. Our findings support thyroid hormones as being necessary for the expression of changes in morphology and physiology associated with migration as well as migratory behavior itself. Copyright © 2016 Elsevier Inc. All rights reserved.

  19. Seasonal variations in daily rhythms of activity in athletic horses.

    PubMed

    Bertolucci, C; Giannetto, C; Fazio, F; Piccione, G

    2008-07-01

    Circadian rhythms reflect extensive programming of biological activity that meets and exploits the challenges and opportunities offered by the periodic nature of the environment. In the present investigation, we recorded the total activity of athletic horses kept at four different times of the year (vernal equinox, summer solstice, autumn equinox and winter solstice), to evaluate the presence of seasonal variations of daily activity rhythms. Athletic Thoroughbred horses were kept in individual boxes with paddock. Digitally integrated measure of total activity of each mare was continuously recorded by actigraphy-based data loggers. Horse total activities were not evenly distributed over the day, but they were mainly diurnal during the year. Daily activity rhythms showed clear seasonal variations, with the highest daily amount of activity during the vernal equinox and the lowest during the winter solstice. Interestingly, the amount of activity during either photophase or scotophase changed significantly throughout the year. Circadian analysis of horse activities showed that the acrophase, the estimated time at which the peak of the rhythm occurs, did not change during the year, it always occurred in the middle of the photoperiod. Analysing the time structure of long-term and continuously measured activity and feeding could be a useful method to critically evaluate athletic horse management systems in which spontaneous locomotor activity and feeding are severely limited. Circadian rhythms are present in several elements of sensory motor and psychomotor functions and these would be taken into consideration to plan the training schedules and competitions in athletic horses.

  20. An analysis of the ionosphere around equinoxes from the COSMIC radio occultation and other observations

    NASA Astrophysics Data System (ADS)

    Liu, Libo; Wan, Weixing; He, Maosheng; Yue, Xinan

    The seasonal behaviors of the ionosphere have been investigated for many decades, but the differences of the ionosphere between the March and September Equinoxes are still lacking investigations. In this report we utilize data of ionospheric electron density (Ne) profiles from COSMIC radio occultation measurements, total electron density (TEC) from TOPEX and Jason-1, and TEC from Global Positioning System (GPS) receivers as well as global ionosonde measurements of the F2 layer critical frequency to investigate the behaviors of the daytime ionosphere around equinoxes at low solar activity (LSA). With the comination of the data from the above sources, we characterize the intensity of the differences between the two equinoxes. The equinoctial differences show a latitudinal dependence as well as an altitude pattern. Our result indicates that the principal difference of the ionosphere are centered around the crest latitudes of the equatorial ionization anomaly. There are some discrepancies in the equinoctial differences shown in these data sources. This work is supported by National Natural Science Foundation of China (40725014). This study made use of IRO data from the COSMIC Data Analysis and Archive Center (CDAAC). Ionosonde data are provided from National Institute of Information and Communications Technology, IPS Radio and Space Services of Australia, and from SPIDR. The JPL GIMs are downloaded from the site: ftp://cddis.gsfc.nasa.gov. TOPEX/POSEIDON and Jason-1 dataset is produced and distributed by the JPL, Physical Oceanography Distributed Active Archive Center.

  1. Monitoring the vernal advancement and retrogradation (green wave effect) of natural vegetation

    NASA Technical Reports Server (NTRS)

    Rouse, J. W., Jr. (Principal Investigator)

    1973-01-01

    The author has identified the following significant results. A comprehensive review of ERTS-1 MSS color composite imagery, obtained during the autumnal and vernal phases over the Great Plains Corridor test sites, shows that temporal changes in rangeland vegetation can be manually interpreted. The degree to which manual interpretations can be made from the MSS color composites appears to be limited primarily by variations in image reproduction quality. The vernal advancement and other phenophase related phenomena are observable from cycle to cycle and within a single frame for rangeland vegetation. Vegetation changes due to environmental conditions among the test sites and among grazing treatments within test sites are readily observable. An investigation has been initiated which will evaluate band-to-band ratios as an index of rangeland vegetation condition. Data currently available from August 1972 through April 1973 for the five southern test sites are being used to characterize band-to-band ratios as a function of quantity and quality of rangeland vegetation at each of the test sites.

  2. Corneal Complications And Visual Impairment In Vernal Keratoconjunctivitis Patients.

    PubMed

    Arif, Abdus Salam; Aaqil, Bushra; Siddiqui, Afsheen; Nazneen, Zainab; Farooq, Umer

    2017-01-01

    Vernal kerato-conjunctivitis (VKC) is an infrequent but serious form of allergic conjunctivitis common in warm and humid areas where air is rich in allergens. It affects both eyes asymmetrically. Although VKC is a self-limiting disease but visions affecting corneal complications influence the quality of life in school children. The aim of this study was to list the corneal complications due to this condition and to find out the extent of visual impairment among VKC patients. This cross-sectional study was conducted in the department of Ophthalmology, Benazir Bhutto Shaheed Hospital on 290 eyes of diagnosed cases of VKC. The diagnosis of VKC was made on the basis of history and examination. Visual acuity was recorded using Snellen's notation and visual impairment was classified according to World Health Organization classification for visual disabilities. The mean age of presentation was 10.83±6.13 years. There were 207 (71.4%) males and 83 (28.6%) females. Corneal scarring was observed in 59 (20.3%) eyes. Keratoconus was found to be in 17 (5.9%) eyes. Shield ulcer was detected in 09 (3.1%) eyes while 07 (2.4%) eyes had corneal neovascularization. Majority of the patients with visual loss had corneal scarring and the complication that led to severe visual loss in most of the eyes was Keratoconus. Vernal kerato-conjunctivitis in the presence of corneal complications is a sight threatening disease and can lead to severe visual impairment.

  3. Lunar ephemeris and selenographic coordinates of the earth and sun for 1971 and 1972

    NASA Technical Reports Server (NTRS)

    Hartung, A. D.

    1972-01-01

    Ephemeris data are presented for each month of 1971 and 1972 to provide a time history of lunar coordinates and related geometric information. A NASA Manned Spacecraft Center modification of the Jet Propulsion Laboratory ephemeris tape was used to calculate and plot coordinates of the earth, moon, and sun. The ephemeris is referenced to the mean vernal equinox at the nearest beginning of a Besselian year. Therefore, the reference equinox changes from one year to the next between 30 June and 1 July. The apparent discontinuity in the data is not noticeable in the graphical presentation, but can be observed in the digital output. The mean equator of epoch is used in all cases. The computer program used to compute and plot the ephemeris data is described.

  4. Lunar ephemeris and selenographic coordinates of the earth and sun for 1973 and 1974

    NASA Technical Reports Server (NTRS)

    Hartung, A. D.

    1972-01-01

    Ephemeris data are presented for each month of 1973 and 1974 to provide a time history of lunar coordinates and related geometric information. A NASA Manned Spacecraft Center modification of the Jet Propulsion Laboratory ephemeris tape was used to calculate and plot coordinates of the earth, moon, and sun. The ephemeris is referenced to the mean vernal equinox at the nearest beginning of a Besselian year. Therefore, the reference equinox changes from one year to the next between 30 June and 1 July. The apparent discontinuity in the data is not noticeable in the graphical presentation, but can be observed in the digital output. The mean equator of epoch is used in all cases. The computer program used to compute and plot the ephemeris data is described.

  5. Supra-tarsal injection of dexamethasone in the treatment of patients with refractory vernal keratoconjunctivitis.

    PubMed

    Lisanework, Mulu

    2003-01-01

    The response to supratarsal injection of dexamethasone in severe refractory vernal keratoconjunctivitis was studied in 20 patients (14 males and 6 females) at the ophthalmology department of Menelik II Hospital, Addis Ababa in 1997. Majority of the patients were in the age range of 11-20 years with mean age of 14.6 years. Although all patients experienced relief of symptoms in the first 2 days of dexamethasone injection, symptoms recurred in the majority 16 (80%) of the patients. Cobble stone papillae and limbal signs disappeared in 2 (11%) and 5 (38%) of the patients respectively. Resolution of limbal form of the disease is more dramatic when compared to the palpebral form. This study showed that supratarsal injection of dexamethasone in severe vernal keratoconjunctivitis is effective in few, partially effective in some and ineffective in many of our patients. Further studies, particularly a randomized controlled trial is recommended prior to utilization of this new therapeutic modality as a standard form of treatment in Ethiopian patients.

  6. Corneal complications of vernal keratoconjunctivitis.

    PubMed

    Solomon, Abraham

    2015-10-01

    Vernal keratoconjunctivitis (VKC) is a severe bilateral chronic allergic inflammatory disease of the ocular surface. In most of the cases, the disease is limited to the tarsal conjunctiva and to the limbus. However, in the more severe cases, the cornea may be involved, leading to potentially sight threatening complications. Prompt recognition of these complications is crucial in the management of VKC, which is one of the most severe ocular allergic diseases. A vicious cycle of inflammation occurs as a result of a set of reciprocal interactions between the conjunctiva and the cornea, which results in damage to the corneal epithelium and corneal stoma, and to the formation of shield ulcers and plaques, infectious keratitis, keratoconus, scarring, and limbal stem cell deficiency. These corneal complications can cause permanent decrease or loss of vision in children suffering from VKC. Corneal complications in VKC are the result of an on-going process of uncontrolled inflammation. Proper recognition of the corneal complications in VKC is crucial, as most of these can be managed or prevented by a combination of medical and surgical measures.

  7. Lunar ephemeris and selenographic coordinates of the earth and sun for 1979 and 1980

    NASA Technical Reports Server (NTRS)

    Hartung, A. D.

    1972-01-01

    Ephemeris data are presented in sections for each month for 1979 and 1980 to provide a time history of lunar coordinates and related geometric information. A NASA Manned Spacecraft Center modification of an ephemeris tape was used to calculate and plot coordinates of the earth, moon, and sun. The ephemeris is referenced to the mean vernal equinox at the nearest beginning of a Besselian year. Therefore, the reference equinox changes from one year to the next between 30 June and 1 July. The apparent discontinuity in the data is not noticeable in the graphical presentation, but can be observed in the digital output. The mean equator of epoch is used in all cases. The computer program used to compute and plot the ephemeris data is described in the appendix.

  8. Lunar ephemeris and selenographic coordinates of the earth and sun for 1983 and 1984

    NASA Technical Reports Server (NTRS)

    Hartung, A. D.

    1972-01-01

    Ephemeris data are presented in sections for each month for 1983 and 1984 to provide a time history of lunar coordinates and related geometric information. A NASA Manned Spacecraft Center modification of an ephemeris tape was used to calculate and plot coordinates of the earth, moon, and sun. The ephemeris is referenced to the mean vernal equinox at the nearest beginning of a Besselian year. Therefore, the reference equinox changes from one year to the next between 30 June and 1 July. The apparent discontinuity in the data is not noticeable in the graphical presentation, but can be observed in the digital output. The mean equator of epoch is used in all cases. The computer program used to compute and plot the ephemeris data is described in the appendix.

  9. Lunar ephemeris and selenographic coordinates of the earth and sun for 1977 and 1978

    NASA Technical Reports Server (NTRS)

    Hartung, A. D.

    1972-01-01

    Ephemeris data are presented in sections for each month for 1977 and 1978 to provide a time history of lunar coordinates and related geometric information. A NASA Manned Spacecraft Center modification of an ephmeris tape was used to calculate and plot coordinates of the earth, moon, and sun. The ephemeris is referenced to the mean vernal equinox at the nearest beginning of a Besselian year. Therefore, the reference equinox changes from one year to the next between June 30 and July 1. The apparent discontinuity in the data is not noticeable in the graphical presentation, but can be observed in the digital output. The mean equator of epoch is used in all cases. The computer program used to compute and plot the ephemeris data is described in the appendix.

  10. Interpretation of Hydrographic Features Using Landsat Images,

    DTIC Science & Technology

    1981-06-01

    photograph, Western Atlantic Ocean Figure B-2. Apollo 7, Oblique 146 photograph, Gulf of California (October 13, 1968) Figure B-3. Solar elevation 147 angle...of Land,,it imagery uises the the Hotine Oblique Mercator (HOM) map low-gain Linear setting where signals projection. on all four Iiainnels 1lave...Inclination to ecliptic =23.44 ° eliminate sunglint and enhance the A = Sun’s apparent position (00 at water color is to subtract an IR vernal equinox

  11. A Survey of Geosynchronous Satellite Glints

    NASA Astrophysics Data System (ADS)

    Vrba, F.; Hutter, D.; Shankland, P.; Armstrong, J.; Schmitt, H.; Hindsley, R.; Divittorio, M.; Benson, J.

    Artificial satellites have characteristic diffuse reflected-light signatures as they are illuminated at varying phase angles by the Sun and are viewed at differing orientations by an observer. At times of favorable alignment between the satellite, observer and Sun, specular reflection off of relatively flat surfaces, such as solar panels, can cause brief increases in reflected light of several hundred times that of the nominal diffuse signature. Such events are commonly referred to as "glints". In the case of geosynchronous satellites, favorable glint alignments are due to changes in the Sun-Vehicle-Observer angle which are primarily due to the apparent motion of the Sun as the observer-satellite vector remains nearly stationary. These occur near in time to the vernal and autumnal equinoxes. While the most favorable geosynchronous satellite glint alignments are precluded by the fact that the satellites are at that time most likely to be in Earth shadow, observations of several glints have been reported in the literature. While such studies note the peak brightnesses, durations, and phase angles of individual glints, to our knowledge, no extended study of geosynchronous glint characteristics exists. Beginning with the autumnal equinox glint season of 2007 we have built on our earlier studies using the U.S. Naval Observatory, Flagstaff Station 40-inch Ritchey telescope to provide near-real-time astrometric and photometric information for use by the Navy Prototype Optical Interferometer (NPOI) team in its efforts to obtain interferometric fringes of geosynchronous satellites during a glint episode. The combined observations culminated in successful fringe measurements of DirecTV-9S during the vernal equinox 2008 and 2009 seasons (see Armstrong, et al. 2009, this conference). For our 40-inch telescope observations we used an LN2-cooled 2048x2048 CCD with standard R-band and H-alpha photometric filters, covering an area of the sky of approximately 22x22 arcmin with each

  12. O-GlcNAc-mediated interaction between VER2 and TaGRP2 elicits TaVRN1 mRNA accumulation during vernalization in winter wheat

    PubMed Central

    Xiao, Jun; Xu, Shujuan; Li, Chunhua; Xu, Yunyuan; Xing, Lijing; Niu, Yuda; Huan, Qing; Tang, Yimiao; Zhao, Changping; Wagner, Doris; Gao, Caixia; Chong, Kang

    2014-01-01

    Vernalization, sensing of prolonged cold, is important for seasonal flowering in eudicots and monocots. While vernalization silences a repressor (FLC, MADS-box transcription factor) in eudicots, it induces an activator (TaVRN1, an AP1 clade MADS-box transcription factor) in monocots. The mechanism for TaVRN1 induction during vernalization is not well understood. Here we reveal a novel mechanism for controlling TaVRN1 mRNA accumulation in response to prolonged cold sensing in wheat. The carbohydrate-binding protein VER2, a jacalin lectin, promotes TaVRN1 upregulation by physically interacting with the RNA-binding protein TaGRP2. TaGRP2 binds to TaVRN1 pre-mRNA and inhibits TaVRN1 mRNA accumulation. The physical interaction between VER2 and TaGRP2 is controlled by TaGRP2 O-GlcNAc modification, which gradually increases during vernalization. The interaction between VER2 and O-GlcNAc-TaGRP2 reduces TaGRP2 protein accumulation in the nucleus and/or promotes TaGRP2 dissociation from TaVRN1, leading to TaVRN1 mRNA accumulation. Our data reveal a new mechanism for sensing prolonged cold in temperate cereals. PMID:25091017

  13. Teasing Apart the Effects of Atmospheric Nitrogen Deposition from Grazing and Drought in Vernal Pool Wetlands and Adjacent Grassland

    NASA Astrophysics Data System (ADS)

    Fogel, M. L.; Araiza, D. N.; Nakamoto, B. J.; Vega, M. C.; Bradley, C. J.; Swarth, C. W.

    2014-12-01

    The remaining vernal pools flanking California's Central Valley may be protected from development, but they are not pristine environments. At UC Merced's Vernal Pools and Grassland Reserve, dairy cattle grazing is a fact of life, needed to keep non-native grasses from encroaching on and dominating these low lying, ephemeral pools. In addition to grazing, atmospheric deposition of nitrogen from adjacent agricultural farms and dairies has affected the biogeochemical cycling here, in particular because the area has never been ploughed and is essentially a terminal, interior catchment with almost no outputs. For the past two years, the region has been subjected to extreme drought resulting in altered patterns in vernal pool development and nutrient exchange. We are using stable nitrogen, carbon, and hydrogen isotopes in organic and inorganic reservoirs to understand which of the three stressors (e.g. N loading, grazing, or drought) affects the ecosystem functioning the most. Simple measurements of residual dry matter (the rancher's standard) coupled with soil analyses and plant distribution, isotopic composition, and productivity will be presented at a landscape scale. Atmospheric deposition, as rain in winter and early spring and as dust in summer and fall, delivers substantial ammonium and nitrate to the Reserve and could be traced back to nearby hotspots, as well as from major storm systems. Concentrations and compositions of N in precipitation were highly variable depending on when the last storm event had occurred. Ammonia/ammonium in rainwater ranged from δ15N= -24 to +7‰, probably explaining the large range in the δ15N of plant tissues collected in winter/spring (-4.3 to +10.9‰,) and that of extractable ammonium from surface soils (δ15N = -7 to +13‰). Interior grassland and vernal pool ecosystems, with substantial inputs and little to no outputs, host biogeochemical processes that amplify heterogeneity on relative small scales.

  14. The promoter of the cereal VERNALIZATION1 gene is sufficient for transcriptional induction by prolonged cold.

    PubMed

    Alonso-Peral, Maria M; Oliver, Sandra N; Casao, M Cristina; Greenup, Aaron A; Trevaskis, Ben

    2011-01-01

    The VERNALIZATION1 (VRN1) gene of temperate cereals is transcriptionally activated by prolonged cold during winter (vernalization) to promote flowering. To investigate the mechanisms controlling induction of VRN1 by prolonged cold, different regions of the VRN1 gene were fused to the GREEN FLUORESCENT PROTEIN (GFP) reporter and expression of the resulting gene constructs was assayed in transgenic barley (Hordeum vulgare). A 2 kb segment of the promoter of VRN1 was sufficient for GFP expression in the leaves and shoot apex of transgenic barley plants. Fluorescence increased at the shoot apex prior to inflorescence initiation and was subsequently maintained in the developing inflorescence. The promoter was also sufficient for low-temperature induction of GFP expression. A naturally occurring insertion in the proximal promoter, which is associated with elevated VRN1 expression and early flowering in some spring wheats, did not abolish induction of VRN1 transcription by prolonged cold, however. A translational fusion of the promoter and transcribed regions of VRN1 to GFP, VRN1::GFP, was localised to nuclei of cells at the shoot apex of transgenic barley plants. The distribution of VRN1::GFP at the shoot apex was similar to the expression pattern of the VRN1 promoter-GFP reporter gene. Fluorescence from the VRN1::GFP fusion protein increased in the developing leaves after prolonged cold treatment. These observations suggest that the promoter of VRN1 is targeted by mechanisms that trigger vernalization-induced flowering in economically important temperate cereal crops.

  15. Planetary period oscillations in Saturn's magnetosphere: Further comments on the relationship between post-equinox properties deduced from magnetic field and Saturn kilometric radiation measurements

    NASA Astrophysics Data System (ADS)

    Cowley, S. W. H.; Provan, G.

    2016-07-01

    We discuss the planetary period oscillations (PPOs) observed by the Cassini spacecraft in Saturn's magnetosphere, in particular the relationship between the properties of the PPOs in the post-equinox interval as observed in magnetic field data by Andrews et al. (2012) and Provan et al. (2013, 2014) and in Saturn kilometric radiation (SKR) emissions by Fischer et al. (2014, 2015), whose results are somewhat discrepant. We show that differences in the reported PPO periods, a fundamental property which should be essentially identical in the two data sets, can largely be accounted for by the phenomenon of dual modulation of the SKR emissions in polarization-separated data, in which the modulation associated with one hemisphere is also present in the other. Misidentification of the modulations results in a reported reversal in the SKR periods in the initial post-equinox interval, south for north and vice versa, relative to the magnetic oscillations whose hemispheric origin is more securely identified through the field component phase relations. Dual modulation also results in the apparent occurrence of phase-locked common periods in the northern and southern SKR data during later intervals during which two separate periods are clearly discerned in the magnetic data through beat modulations in both phase and amplitude. We further show that the argument of Fischer et al. (2015) concerning the phase relation between the magnetic field oscillations and the SKR modulations is erroneous, the phase difference between them revealing the local time (LT) of the upward field-aligned current of the PPO current system at times of SKR modulation maxima. Furthermore, this LT is found to vary significantly over the Cassini mission from dawn, to dusk, and to noon, depending on the LT of apoapsis where the spacecraft spends most time. These variations are consistent with the view that the SKR modulation is fundamentally a rotating system like the magnetic perturbations, though

  16. The Variation of Hydrocarbon Abundances with Latitude and Season in Saturn's Stratosphere

    NASA Technical Reports Server (NTRS)

    Moses, J. I.; Greathouse, T. K.

    2005-01-01

    We have developed a realistic, time-variable, one-dimensional, seasonal model for stratospheric photochemistry on Saturn using the Caltech/ JPL KINETICS code [1,2,3]. The model accounts for variations in ultraviolet flux due to orbital position, solar-cycle variations, and ring-shadowing effects. The results for two Saturnian years, starting at Ls = 0 in 1950 and running until the upcoming northern vernal equinox in 2009, are presented for numerous latitudes. The same two model years are run over and over again until the model convergences to make sure that high-altitude effects have had a chance to propagate down through the atmosphere. We use the SOLAR2000 model [4,5], in combination with the spectra presented in [6], to predict the ultraviolet flux at any wavelength and any point in time during the simulation. Saturn's orbital position during the simulation was taken from the ephemeris calculator at http://ssd.jpl.nasa.gov/horizons.html [7]. The photochemical model is derived from "Model C" of [8] and uses a hydrocarbon reaction list that has been extensively updated from that presented in [3].

  17. Three Dimensional Orbital Stability About the Earth-Moon Equilateral Libration Points.

    DTIC Science & Technology

    1980-12-01

    need to be rotated to the ecliptic . If e is the obliquity of the ecliptic , then the transformation matrix for this is: t F e, ’ C]u 11E -12 IF I) I...the use of the above transformation matrix. The frame for the analysis of the problem will be an Earth-centered ecliptic nonrotating rectangular system...The X-axis will point toward the vernal equinox and the Z-axis will be perpendicular to the ecliptic having the XY-plane coincident with the ecliptic

  18. Acute Sensitivity of the Vernal Pool Fairy Shrimp, Branchinecta Lynchi (Anostraca; Branchinectidae), and Surrogate Species to 10 Chemicals

    EPA Science Inventory

    Vernal pool fairy shrimp, Branchinecta lynchi, (Branchiopoda; Anostraca) and other fairy shrimp species have been listed as threatened or endangered under the US Endangered Species Act. Because few data exist about the sensitivity of Branchinecta spp. to toxic effects of contamin...

  19. Quipus and System of Coordinated Precession

    NASA Astrophysics Data System (ADS)

    Campos, T. C.

    2004-05-01

    The Incas of ancient Peru possessed no writing. Instead, they developed a unique system expressed on spatial arrays of colored knotted cords called Quipus to record and transmit information throughout their vast empire. In their thorough description of quipus, Ascher & Ascher observed that in two cases the numbers registered in their strings have a very special relationship to each other. For this to occur the numbers must have been obtained through the multiplication of whole numbers by fractions or decimals, operations apparently beyond the arithmetic knowledge of the Incas. The quipus AS120 and AS143, coming from Ica (Peru) and conserved in the Museum of Berlin has the suitable characteristics previously. In the AS143 there is a the relationship with the systems of coordinated precession (tilt of Earth's spin axis (40036); eccentricity of Earth's orbit (97357); and precession of equinoxes (between 18504 and 23098)). For the history of the Earth are necessary an chronometer natural to coordinate and to classify the observations and this chronometer comes to be the vernal point, defining the vernal point as" a sensitive axis of maximum conductivity" as itdemonstrates it the stability of the geomagnetic equator (inclination of the field is zero grades), in the year 1939 calculated with the IGRF from the year 1900 up to the 2004 and that it is confirmed with tabulated data of the Geophysical Institute of Huancayo (Peru),from that date until this year (2004) and this fluctuating between the 12-14 South.,on the other hand in the area of Brazil it has advanced very quickly toward the north, and above to 108 km. approximately it is located the equatorial electrojet that is but intense in the equinoxes in South America. And this stability from the point of view of the precession of the equinoxes this coinciding with the entrance of the apparent sun for the constellation of Aquarius, being this mechanism the base to establish a system of coordinated precession where it is

  20. 78 FR 17709 - Endangered and Threatened Wildlife and Plants; Recovery Plan for Rogue and Illinois Valley Vernal...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-22

    ...-FF01E00000] Endangered and Threatened Wildlife and Plants; Recovery Plan for Rogue and Illinois Valley Vernal... addresses two endangered plant species that are endemic to southern Oregon, and also includes some... Federal List of Endangered and Threatened Wildlife and Plants. ADDRESSES: An electronic copy of the...

  1. Anthropogenic Mercury Accumulation in Watersheds of the Northern Appalachian Mountains

    NASA Astrophysics Data System (ADS)

    Boyer, E. W.; Drohan, P. J.; Lawler, D.; Grimm, J.; Grant, C.; Eklof, K. J.; Bennett, J.; Naber, M. D.

    2014-12-01

    Atmospheric deposition of mercury (Hg) is a critical environmental stress that affects ecosystems and human health. Mercury emissions to the atmosphere from coal-fired power plants and other sources such as waste incineration can be deposited over large geographic areas to downwind landscapes in precipitation and in dry fallout. The northern Appalachian Mountains are downwind of major atmospheric mercury emissions sources. Some mercury reaches watersheds and streams, where it can accumulate in sediments and biota. Human exposure to mercury occurs primarily through fish consumption, and currently mercury fish eating advisories are in place for many of the streams and lakes in the region. Here, we explored mercury accumulation in forested landscapes - in air, soils, water, and biota. To quantify atmospheric mercury deposition, we measured both wet and dry mercury deposition at 10 forested locations, from which we present variation in mercury deposition and initial assessments of factors affecting the patterns. To quantify mercury accumulation in terrestrial environments, we measured soil mercury concentrations within and surrounding 12 vernal pools spanning various physiographic settings in the region. Given that vernal pools have large inputs of water via precipitation yet do not have any stream discharge outflow, they are likely spots within the forested landscape to accumulate pollutants that enter via wet atmospheric deposition. To quantify mercury accumulation in aquatic environments, we sampled mercury concentrations in streams draining 35 forested watersheds, spanning gradients of atmospheric deposition, climate and geology. Mercury concentrations were measured in stream water under base-flow conditions, in streambed sediments, aquatic mosses, and in fish tissues from brook trout. Results indicate that wet and dry atmospheric deposition is a primary source of mercury that is accumulating in watersheds of the Northern Appalachian Mountains.

  2. Planetary period oscillations in Saturn's magnetosphere: comments on the relation between post-equinox periods determined from magnetic field and SKR emission data

    NASA Astrophysics Data System (ADS)

    Cowley, S. W. H.; Provan, G.

    2015-07-01

    We discuss the properties of Saturn planetary period oscillations (PPOs) deduced from analysis of Saturn kilometric radiation (SKR) modulations by Fischer et al. (2014), and from prior analysis of magnetic field oscillations data by Andrews et al. (2012) and Provan et al. (2013), with emphasis on the post-equinox interval from early 2010 to early 2013. Fischer et al. (2014) characterize this interval as showing single phase-locked periods in the northern and southern SKR modulations observed in polarization-separated data, while the magnetic data generally show the presence of separated dual periods, northern remaining shorter than southern. We show that the single SKR period corresponds to the southern magnetic period early in 2010, segues into the northern period in late 2010, and returns to the southern period in mid-2012, approximately in line with changes in the dominant magnetic oscillation. An exception occurs in mid-February to late August 2011 when two periods are again discerned in SKR data, in good agreement with the ongoing dual periods in the magnetic data. Fischer et al. (2014) discuss this change in terms of a large jump in the southern SKR period related to the Great White Spot storm, which the magnetic data show is primarily due instead to a reappearance in the SKR data of the ongoing southern modulation in a transitory interval of resumed southern dominance. In the earlier interval from early April 2010 to mid-February 2011 when Fischer et al. (2014) deduce single phase-locked periods, we show unequivocal evidence in the magnetic data for the presence of separated dual oscillations of approximately equal amplitude. We suggest that the apparent single SKR periods result from a previously reported phenomenon in which modulations associated with one hemisphere appear in polarization-separated data associated with the other. In the following interval, mid-August 2011 to early April 2012, when Fischer et al. (2014) again report phase-locked northern

  3. The effect of day-neutral mutations in barley and wheat on the interaction between photoperiod and vernalization.

    PubMed

    Turner, Adrian S; Faure, Sébastien; Zhang, Yang; Laurie, David A

    2013-09-01

    Vernalization-2 (Vrn-2) is the major flowering repressor in temperate cereals. It is only expressed under long days in wild-type plants. We used two day-neutral (photoperiod insensitive) mutations that allow rapid flowering in short or long days to investigate the day length control of Vrn-2. The barley (Hordeum vulgare) early maturity8 (eam8) mutation affects the barley ELF3 gene. eam8 mutants disrupt the circadian clock resulting in elevated expression of Ppd-H1 and the floral activator HvFT1 under short or long days. When eam8 was crossed into a genetic background with a vernalization requirement Vrn-2 was expressed under all photoperiods and the early flowering phenotype was partially repressed in unvernalized (UV) plants, likely due to competition between the constitutively active photoperiod pathway and the repressing effect of Vrn-2. We also investigated the wheat (Triticum aestivum) Ppd-D1a mutation. This differs from eam8 in causing elevated levels of Ppd-1 and TaFT1 expression without affecting the circadian clock. We used genotypes that differed in "short-day vernalization". Short days were effective in promoting flowering in individuals wild type at Ppd-D1, but not in individuals that carry the Ppd-D1a mutation. The latter showed Vrn-2 expression in short days. In summary, eam8 and Ppd-D1a mimic long days in terms of photoperiod response, causing Vrn-2 to become aberrantly expressed (in short days). As Ppd-D1a does not affect the circadian clock, this also shows that clock regulation of Vrn-2 operates indirectly through one or more downstream genes, one of which may be Ppd-1.

  4. Morphology, Carbohydrate Composition and Vernalization Response in a Genetically Diverse Collection of Asian and European Turnips (Brassica rapa subsp. rapa)

    PubMed Central

    Zhang, Ningwen; Zhao, Jianjun; Lens, Frederic; de Visser, Joan; Menamo, Temesgen; Fang, Wen; Xiao, Dong; Bucher, Johan; Basnet, Ram Kumar; Lin, Ke; Cheng, Feng; Wang, Xiaowu; Bonnema, Guusje

    2014-01-01

    Brassica rapa displays enormous morphological diversity, with leafy vegetables, turnips and oil crops. Turnips (Brassica rapa subsp. rapa) represent one of the morphotypes, which form tubers and can be used to study the genetics underlying storage organ formation. In the present study we investigated several characteristics of an extensive turnip collection comprising 56 accessions from both Asia (mainly Japanese origin) and Europe. Population structure was calculated using data from 280 evenly distributed SNP markers over 56 turnip accessions. We studied the anatomy of turnip tubers and measured carbohydrate composition of the mature turnip tubers of a subset of the collection. The variation in 16 leaf traits, 12 tuber traits and flowering time was evaluated in five independent experiments for the entire collection. The effect of vernalization on flowering and tuber formation was also investigated. SNP marker profiling basically divided the turnip accessions into two subpopulations, with admixture, generally corresponding with geographical origin (Europe or Asia). The enlarged turnip tuber consists of both hypocotyl and root tissue, but the proportion of the two tissues differs between accessions. The ratio of sucrose to fructose and glucose differed among accessions, while generally starch content was low. The evaluated traits segregated in both subpopulations, with leaf shape, tuber colour and number of shoots per tuber explaining most variation between the two subpopulations. Vernalization resulted in reduced flowering time and smaller tubers for the Asian turnips whereas the European turnips were less affected by vernalization. PMID:25474111

  5. The Energetics of Transient Eddies in the Martian Northern Hemisphere

    NASA Astrophysics Data System (ADS)

    Battalio, Joseph Michael; Szunyogh, Istvan; Lemmon, Mark T.

    2016-10-01

    The energetics of northern hemisphere transient waves in the Mars Analysis Correction Data Assimilation is analyzed. Three periods between the fall and spring equinoxes (Ls=200°-230°, 255°-285°, and 330°-360°) during three Mars Years are selected to exemplify the fall, winter, and spring wave activity. Fall and spring eddy energetics is similar with some inter-annual and inter-seasonal variability, but winter eddy kinetic energy and its transport are strongly reduced in intensity as a result of the solsticial pause in eddy activity. Barotropic energy conversion acts as a sink of eddy kinetic energy throughout the northern hemisphere eddy period with little reduction in amplitude during the solsticial pause. Baroclinic energy conversion acts as a source in fall and spring but disappears during the winter period as a result of the stabilized vertical shear profile of the westerly jet around winter solstice.

  6. Improving management of small natural features on private lands by negotiating the science-policy boundary for Maine vernal pools.

    PubMed

    Calhoun, Aram J K; Jansujwicz, Jessica S; Bell, Kathleen P; Hunter, Malcolm L

    2014-07-29

    Vernal pools are far more important for providing ecosystem services than one would predict based on their small size. However, prevailing resource-management strategies are not effectively conserving pools and other small natural features on private lands. Solutions are complicated by tensions between private property and societal rights, uncertainties over resource location and function, diverse stakeholders, and fragmented regulatory authority. The development and testing of new conservation approaches that link scientific knowledge, stakeholder decision-making, and conservation outcomes are important responses to this conservation dilemma. Drawing from a 15-y history of vernal pool conservation efforts in Maine, we describe the coevolution of pool conservation and research approaches, focusing on how research-based knowledge was produced and used in support of management decisions. As management shifted from reactive, top-down approaches to proactive and flexible approaches, research shifted from an ecology-focused program to an interdisciplinary program based on social-ecological systems. The most effective strategies for linking scientific knowledge with action changed as the decision-makers, knowledge needs, and context for vernal pool management advanced. Interactions among stakeholders increased the extent to which knowledge was coproduced and shifted the objective of stakeholder engagement from outreach to research collaboration and development of innovative conservation approaches. New conservation strategies were possible because of the flexible, solutions-oriented collaborations and trust between scientists and decision-makers (fostered over 15 y) and interdisciplinary, engaged research. Solutions to the dilemma of conserving small natural features on private lands, and analogous sustainability science challenges, will benefit from repeated negotiations of the science-policy boundary.

  7. Improving management of small natural features on private lands by negotiating the science–policy boundary for Maine vernal pools

    PubMed Central

    Calhoun, Aram J. K.; Jansujwicz, Jessica S.; Bell, Kathleen P.; Hunter, Malcolm L.

    2014-01-01

    Vernal pools are far more important for providing ecosystem services than one would predict based on their small size. However, prevailing resource-management strategies are not effectively conserving pools and other small natural features on private lands. Solutions are complicated by tensions between private property and societal rights, uncertainties over resource location and function, diverse stakeholders, and fragmented regulatory authority. The development and testing of new conservation approaches that link scientific knowledge, stakeholder decision-making, and conservation outcomes are important responses to this conservation dilemma. Drawing from a 15-y history of vernal pool conservation efforts in Maine, we describe the coevolution of pool conservation and research approaches, focusing on how research-based knowledge was produced and used in support of management decisions. As management shifted from reactive, top-down approaches to proactive and flexible approaches, research shifted from an ecology-focused program to an interdisciplinary program based on social–ecological systems. The most effective strategies for linking scientific knowledge with action changed as the decision-makers, knowledge needs, and context for vernal pool management advanced. Interactions among stakeholders increased the extent to which knowledge was coproduced and shifted the objective of stakeholder engagement from outreach to research collaboration and development of innovative conservation approaches. New conservation strategies were possible because of the flexible, solutions-oriented collaborations and trust between scientists and decision-makers (fostered over 15 y) and interdisciplinary, engaged research. Solutions to the dilemma of conserving small natural features on private lands, and analogous sustainability science challenges, will benefit from repeated negotiations of the science–policy boundary. PMID:25002496

  8. Vertical cloud structure of Uranus from UKIRT/UIST observations and changes seen during Uranus’ northern spring equinox from 2006 to 2008

    NASA Astrophysics Data System (ADS)

    Irwin, P. G. J.; Teanby, N. A.; Davis, G. R.

    2009-09-01

    Long-slit spectroscopy observations of Uranus by the United Kingdom Infrared Telescope UIST instrument in 2006, 2007 and 2008 have been used to monitor the change in Uranus' vertical and latitudinal cloud structure through the planet's northern spring equinox in December 2007. The observed reflectance spectra in the Long J (1.17-1.31 μm) and H (1.45-1.65 μm) bands, obtained with the slit aligned along Uranus' central meridian, have been fitted with an optimal estimation retrieval model to determine the vertical cloud profile from 0.1 to 6-8 bar over a wide range of latitudes. Context images in a number of spectral bands were used to discriminate general zonal cloud structural changes from passing discrete clouds. From 2006 to 2007 reflection from deep clouds at pressures between 2 and 6-8 bar increased at all latitudes, although there is some systematic uncertainty in the absolute pressure levels resulting from extrapolating the methane coefficients of Irwin et al. (Irwin, P.G.J., Sromovsky, L.A., Strong, E.K., Sihra, K., Teanby, N.A., Bowles, N., Calcutt, S.B., Remedios, J.J. [2006] Icarus, 181, 309-319) at pressures greater than 1 bar, as noted by Tomasko et al. and Karkoschka and Tomasko (Tomasko, M.G., Bezard, B., Doose, L., Engel, S., Karkoschka, E. [2008] Planet. Space Sci., 56, 624-647; Karkoschka, E., Tomasko, M. [2009] Icarus). However, from 2007 to 2008 reflection from these clouds throughout the southern hemisphere and from both northern and southern mid-latitudes (30° N,S) diminished. As a result, the southern polar collar at 45°S has diminished in brightness relative to mid-latitudes, a similar collar at 45°N has become more prominent (e.g. Rages, K.A., Hammel, H.B., Sromovsky, L. [2007] Bull. Am. Astron. Soc., 39, 425; Sromovsky, L.A., Fry, P.M., Ahue, W.M., Hammel, H.B., de Pater, I., Rages, K.A., Showalter, M.R., van Dam, M.A. [2008] vol. 40 of AAS/Division for Planetary Sciences Meeting Abstracts, pp. 488-489; Sromovsky, L.A., Ahue, W

  9. Atmospheric chemical and thermal structure evolution after one Titanian year

    NASA Astrophysics Data System (ADS)

    Coustenis, A.; Bampasidis, G.; Vinatier, S.; Achterberg, R.; Lavvas, P.; Nixon, C.; Jennings, D.; Teanby, N.; Flasar, F. M.; Carlson, R.; Orton, G.; Romani, P.; Guandique, E. A.

    2012-09-01

    We analyze Cassini Composite Infrared Spectrometer (CIRS) data taken during the numerous Titan flybys from 2004-2010 and compare them to the 1980 Voyager 1 flyby values inferred from the re-analysis of the Infrared Radiometer Spectrometer (IRIS) spectra. Seven years after Cassini's Saturn orbit insertion, we look at the evolution of the chemical composition by combining these recordings and the intervening ground- and space- based observations, we have in hand almost a complete picture of the stratospheric evolution within a Titan year. The fulfillment of one Titanian year of observations provides us for the first time with the opportunity to evaluate the relative role of different physical processes in the long-term evolution of this complex environment. By comparing V1 (1980), ISO (1997) and Cassini (2010) we find that a reversal of composition near the equator from autumnal equinox to vernal equinox (1996 min -2009 max, half a year), as well as some differences in polar enhancement at the same era as Voyager.

  10. Lunar ephemeris and selenographic coordinates of the earth and sun for 1981 and 1982

    NASA Technical Reports Server (NTRS)

    Hartung, A. D.

    1972-01-01

    Ephemeris data are presented in sections for each month for 1981 and 1982 to provide a time history of lunar coordinates and related geometric information. A NASA Manned Spacecraft Center (MSC) modification of the Jet Propulsion Laboratory ephemeris tape was used to calculate and plot coordinates of the earth, moon, and sun. The ephemeris is referenced to the mean vernal equinox at the nearest beginning of a Besselian year. Therefore, the reference equinox changes from one year to the next between June 30 and July 1. The apparent discontinuity in the data is not noticeable in the graphical presentation, but can be observed in the digital output. The mean equator of epoch is used in all cases. For 1966 to 1970, the same type of data presentation has been prepared in informal MSC documents. The data for 1971 to 1980 and 1983 and 1984 are presented. The computer program used to compute and plot the ephemeris data is described.

  11. Seasonal Changes in Titan's Surface Temperatures

    NASA Technical Reports Server (NTRS)

    Jennins, Donald E.; Cottini, V.; Nixon, C. A.; Flasar, F. M.; Kunde, V. G.; Samuelson, R. E.; Romani, P. N.; Hesman, B. E.; Carlson, R. C.; Gorius, N. J. P.; hide

    2011-01-01

    Seasonal changes in Titan's surface brightness temperatures have been observed by Cassini in the thermal infrared. The Composite Infrared Spectrometer (CIRS) measured surface radiances at 19 micron in two time periods: one in late northern winter (Ls = 335d eg) and another centered on northern spring equinox (Ls = 0 deg). In both periods we constructed pole-to-pole maps of zonally averaged brightness temperatures corrected for effects of the atmosphere. Between late northern winter and northern spring equinox a shift occurred in the temperature distribution, characterized by a warming of approximately 0.5 K in the north and a cooling by about the same amount in the south. At equinox the polar surface temperatures were both near 91 K and the equator was 93.4 K. We measured a seasonal lag of delta Ls approximately 9 in the meridional surface temperature distribution, consistent with the post-equinox results of Voyager 1 as well as with predictions from general circulation modeling. A slightly elevated temperature is observed at 65 deg S in the relatively cloud-free zone between the mid-latitude and southern cloud regions.

  12. The VERRUN and VERNAL software systems for steady-state visual evoked response experimentation

    NASA Technical Reports Server (NTRS)

    Levison, W. H.; Zacharias, G. L.

    1984-01-01

    Two digital computer programs were developed for use in experiments involving steady-state visual evoked response (VER): VERRUN, whose primary functions are to generate a sum-of-sines (SOS) stimulus and to digitize and store electro-cortical response; and VERNAL, which provides both time- and frequency-domain metrics of the evoked response. These programs were coded in FORTRAN for operation on the PDP-11/34, using the RSX-11 Operating System, and the PDP-11/23, using the RT-11 Operating System. Users' and programmers' guides to these programs are provided, and guidelines for model analysis of VER data are suggested.

  13. Thermal Emission Spectrometer Results: Mars Atmospheric Thermal Structure and Aerosol Distribution

    NASA Technical Reports Server (NTRS)

    Smith, Michael D.; Pearl, John C.; Conrath, Barney J.; Christensen, Philip R.; Vondrak, Richard R. (Technical Monitor)

    2001-01-01

    Infrared spectra returned by the Thermal Emission Spectrometer (TES) are well suited for retrieval of the thermal structure and the distribution of aerosols in the Martian atmosphere. Combined nadir- and limb-viewing spectra allow global monitoring of the atmosphere up to 0.01 mbar (65 km). We report here on the atmospheric thermal structure and the distribution of aerosols as observed thus far during the mapping phase of the Mars Global Surveyor mission. Zonal and temporal mean cross sections are used to examine the seasonal evolution of atmospheric temperatures and zonal winds during a period extending from northern hemisphere mid-summer through vernal equinox (L(sub s) = 104-360 deg). Temperature maps at selected pressure levels provide a characterization of planetary-scale waves. Retrieved atmospheric infrared dust opacity maps show the formation and evolution of regional dust storms during southern hemisphere summer. Response of the atmospheric thermal structure to the changing dust loading is observed. Maps of water-ice clouds as viewed in the thermal infrared are presented along with seasonal trends of infrared water-ice opacity. Uses of these observations for diagnostic studies of the dynamics of the atmosphere are discussed.

  14. Habitat use and life history of the vernal crayfish, Procambarus viaeviridis (Faxon, 1914), a secondary burrowing crayfish in Mississippi, USA

    Treesearch

    Zanethia C. Barnett; Susan B. Adams; Rebecca L.   Rosamond

    2017-01-01

    The Lower Mississippi Alluvial Valley (LMAV) is a species-rich region in North America, but its crayfish community has not been extensively sampled. We investigated the annual life cycle, habitat use, and some morphological characteristics of the vernal crayfish, Procambarus viaeviridis (Faxon, 1914), in the Dahomey National Wildlife Refuge,...

  15. Rotation Matrix from the Mean Dynamical Equator and Equinox at J2000.0 to the ICRS

    DTIC Science & Technology

    2004-01-01

    the ICRS is offset from its equinox by ∆o. The angle 0 is the obliquity of the ecliptic on the ICRS, that is the angle between the ICRS equator and... obliquity is caused solely by a change in the position of the pole of the mean ecliptic . Thus, the sole effect of using the rotating definition of the mean...the mean ecliptic as determined by Chapront et al. from LLR observations (23◦26′21.′′41100 ± 0.′′00005). The angle γy is the separation between the

  16. Expression, purification and preliminary X-ray diffraction studies of VERNALIZATION1208–341 from Arabidopsis thaliana

    PubMed Central

    King, Gordon; Hill, Justine M.; Martin, Jennifer L.; Mylne, Joshua S.

    2009-01-01

    VERNALIZATION1 (VRN1) is required in the model plant Arabidopsis thaliana for the epigenetic suppression of the floral repressor FLC by prolonged cold treatment. Stable suppression of FLC accelerates flowering, a physiological process known as vernalization. VRN1 is a 341-residue DNA-binding protein that contains two plant-specific B3 domains (B3a and B3b), a putative nuclear localization sequence (NLS) and two putative PEST domains. VRN1208–341 includes the second B3 domain and a region upstream that is highly conserved in the VRN1 orthologues of other dicotyledonous plants. VRN1208–341 was crystallized by the hanging-drop method in 0.05 M sodium acetate pH 6.0 containing 1.0 M NaCl and 18%(w/v) PEG 3350. Preliminary X-ray diffraction data analysis revealed that the VRN1208–341 crystal diffracted to 2.1 Å and belonged to space group C2, with unit-cell parameters a = 105.2, b = 47.9, c = 61.2 Å, α = 90.0, β = 115.4, γ = 90.0°. Assuming that two molecules occupy the asymmetric unit, a Matthews coefficient of 2.05 Å3 Da−1 and a solvent content of 40.1% were calculated. PMID:19255487

  17. Hindcasting of Equatorial Spread F Using Seasonal Empirical Models

    NASA Astrophysics Data System (ADS)

    Aswathy, R. P.; Manju, G.

    2018-02-01

    The role of gravity waves in modulating equatorial spread F (ESF) day-to-day variability is investigated using ionosonde data at Trivandrum (geographic coordinates, 8.5°N, 77°E; mean geomagnetic latitude -0.3°N) a magnetic equatorial location. A novel empirical model that incorporates the combined effects of electrodynamics and gravity waves in modulating ESF occurrence during autumnal equinox season was presented by Aswathy and Manju (2017). In the present study, the height variations of the requisite gravity wave seed perturbations for ESF are examined for the vernal equinoxes, summer solstices, and winter solstices of different years. Subsequently, the empirical model, incorporating the electrodynamical effects and the gravity wave modulation, valid for each of the seasons is developed. Accordingly, for each season, the threshold curve may be demarcated provided the solar flux index (F10.7) is known. The empirical models are validated using the data for high, moderate, and low solar activity years corresponding to each season. In the next stage, this model is to be fine tuned to facilitate the prediction of ESF well before its onset.

  18. Monitoring the vernal advancement and retrogradation (green wave effect) of natural vegetation

    NASA Technical Reports Server (NTRS)

    Rouse, J. W., Jr. (Principal Investigator)

    1973-01-01

    The author has identified the following significant results. Continued evaluation of autumnal phase and early vernal phase data indicate that the quality of ERTS-1 imagery over the Great Plains Corridor test sites are adequate to show relatively small temporal changes in the condition and quantity of vegetation at the several test sites. Vegetation changes measured from August through April are observable in reflectance changes recorded by ERTS-1. Vegetation changes due to grazing treatment and environmental conditions at the test sites are being monitored with ground data and ERTS-1 data, and appear adequate to complete all phases of the Great Plains Corridor investigation. NASA high flight aerial photography proved to be an indispensable tool for locating the Great Plains Corridor test sites on the computer derived grey maps of ERTS-1 digital data.

  19. On the occurrence of F region irregularities over Haikou retrieved from COSMIC GPS radio occultation and ground-based ionospheric scintillation monitor observations

    NASA Astrophysics Data System (ADS)

    Yu, Xiao; Yue, Xinan; Zhen, Weimin; Xu, Jisheng; Liu, Dun; Guo, Shan

    2017-01-01

    In this paper, the amplitude scintillation index (s4) derived from COSMIC (Constellation Observing System for Meteorology, Ionosphere, and Climate) radio occultation (RO) technique and ground-based Ionospheric Scintillation Monitor (ISM) at Haikou station (geographic latitude: 20.0°N, geographic longitude: 110.3°E, and geomagnetic latitude: 10.02°N) is used to investigate the morphology of F region irregularities in the low latitudes of China. The RO events of tangent point within the range of 10-30°N latitude, 70-160°E longitude, and 150-500 km altitude are adopted to analyze the ionospheric scintillation characteristics. The percentage of ionospheric scintillation occurrence is computed to obtain its diurnal variations, seasonal trends, and the dependence on solar and geomagnetic activities. Based on a statistical analysis of a long-term period data set (years 2007 to 2013), we found that the ionospheric scintillation occurrence from both techniques show similar variations. After sunset (18 LT), the scintillation occurrence increases rapidly and reaches the maximum 3 h later. Then it decreases rapidly till 04 LT and remains low level during the daytime. The ionospheric scintillation tends to occur more frequently during vernal and autumnal equinoxes, especially in March-April and September-October. The equinoctial asymmetry could be seen clearly from the ground-based ISM observations. The peak ionospheric scintillation occurrence time varies with seasons. It is reached latest in summer, while in spring it is very close to that in autumn. The nighttime ionospheric scintillation occurrence tends to increase with increasing solar activities. The increasing tendency is more prominent in vernal and autumnal equinoxes than that in summer and winter. In general, the control of geomagnetic activities is apt to inhibit ionospheric scintillation at equinox nighttime. In summer and winter, the geomagnetic activities could either trigger or inhibit the generation of

  20. Uranium hydrogeochemical and stream sediment reconnaissance data release for the Red Creek quartzite special study area, Vernal NTMS Quadrangle, Utah/Colorado, including concentrations of forty-six additional elements

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Goff, S.; George, W.E.; Apel, C.T.

    1981-04-01

    Totals of 22 water and 140 sediment samples were collected from 148 locations in the study area. The study area, in the north-central portion of the Vernal NTMS quadrangle, is covered by four 7-1/2' topographic maps: Dutch John, Goslin Mountain, and Clav Basin, Utah; and Willow Creek Butte, Utah/Colorado. Additional HSSR data are available for the entire Vernal quadrangle (Purson, 1980). All field and analytical data are presented in Appendix I. Figure 1 is an index and sample location map that can be used in conjunction with the 1:250,000-scale topographic map of the Vernal quadrangle (USGS, 1954). Standarized field, analytical,more » and data base management procedures were followed in all phases of the study. These procedures are described briefly in Appendix II-A and in reports by Sharp (1977), Hues et al (1977), Sharp and Aamodt (1978), Cheadle (1977), and Kosiewicz (1979). The data presented in Appendix I are available on magnetic tape from GJOIS Project, Union Carbide Corporation (UCC-ND), Computer Applications Department, 4500 North Building, Oak Ridge National Laboratory, P.O. Box X, Oak Ridge, Tennessee 37830. Because this is simply a data release, intended to make the data available to the DOE and the public as quickly as possible, no discussion of the geology of the region, uranium occurrences, or data evaluation is included.« less

  1. Poster 16: Eclipse-induced changes of Titan's meteorology at equinox

    NASA Astrophysics Data System (ADS)

    Tokano, Tetsuya

    2016-06-01

    Titan experiences solar eclipses by Saturn on ˜20 consecutive orbits around equinox for durations of up to ˜6 hours. The impact of these eclipses on Titan's surface, lower atmosphere and middle atmosphere is investigated by a global climate model. When an eclipse commences, the surface temperature on the subsaturnian side drops by up to 0.3 K, so that the diurnal maximum surface temperature remains lower than on the antisaturnian side, which is never eclipsed. By contrast, the tropospheric air temperature does not abruptly decrease during the eclipses because of the large thermal inertia, but the diurnal mean temperature slightly decreases. The surface wind at low latitudes becomes less gusty in the presence of eclipse due to damping of turbulence. The troposphere outside the planetary boundary layer is not sensitive to eclipses. In most parts of the stratosphere and mesosphere the temperature decreases by up to 2 K due to eclipses, but there are also layers, which experience relative warming due to thermal contraction of the underlying layers. The temperature in the middle atmosphere rapidly recovers after the end of the eclipse season. Eclipse-induced cooling and warming changes the zonal wind speed by a few m/s due to thermal wind adjustment to changing latitudinal temperature gradients.

  2. Climatology of GW-TIDs in the magnetic equatorial upper thermosphere over India

    NASA Astrophysics Data System (ADS)

    Manju, G.; Aswathy, R. P.

    2017-11-01

    An analysis of Gravity wave induced travelling ionospheric disturbances (GW-TIDs) in the thermosphere during high and low solar epochs is undertaken using ionosonde data at Trivandrum (8.50N, 770E). Wavelet analysis is performed on the temporal variations of foF2 and the amplitudes of waves present in two period bands of (0.5-1.5) h and (2-4) h are extracted. The real height profiles are generated at 15 min internal for the whole day (for sample days) during high and low solar activity years. The study reveals that the GW-TID activity is significantly greater for solar minimum compared to solar maximum for the period 8.5-17.5 h. Diurnally the GW-TID activity in the (2-4) h period band peaks in the post sunset hours for both high and low solar epochs. For the 0.5-1.5 h period band, the diurnal maximum in GW-TID is occurring in the post sunset hours for high solar epoch while it occurs in the morning hours around 10 h LT for low solar epoch. Seasonally the day time GW-TID activity maximizes (minimizes) for winter (vernal equinox). The post sunset time GW-TID maximizes (minimizes) either for summer/winter (vernal equinox). The other interesting observation is the anti correlation of GW-TID in upper thermosphere with solar activity for day time and the correlation of the same with solar activity in the post sunset hours. The present results for daytime are in agreement with the equatorial daytime GW-TID behaviour reported from CHAMP satellite observations. The GW-TID activity during post sunset time for equatorial region upper thermosphere has not been reported so far.

  3. Aquarius-Pisces Constellation Boundary Update

    NASA Astrophysics Data System (ADS)

    Durst, Steve

    2017-06-01

    Observation, mapping and study of Galaxy Stars has provided humanity direction, foundation, clarity and understanding through the ages.Human civilization advances itself using increasing intelligence and knowledge to develop tools and know how, the science of constellation star maps included: All that has been created by humanity, is to serve humanity.When people continue to use constellation star maps that no longer serve people effectively, the maps are updated, as is now the Aquarius-Pisces Constellation Boundary Update (APCBU), which marks 2000 as the year the Sun is in Aquarius at the vernal equinox.The 21st Century APCBU accounts for and incorporates science factors of precession, relativity and galacticity for professional astronomers, and social imperatives of increasing freedom, liberation and egalitarian culture for the 7.5 billion people of Earth.Twenty years into this first century of a new millennium and a new age is an effective time for an APCBU of such elegant simplicity that it changes less than 0.1% of the area of the IAU 1930 official constellation map, which marks 2597 about the year the Sun is in Aquarius at the time of the vernal equinox.The 21st Century APCBU results provide clarity and direction for humanity's next 2,000 years, if not 10,000 or 12,000 years, and advance the official astronomy / science start of the Aquarius Age -- long anticipated, desired, and imperative, especially in America -- by some 600 years.How much attention is increasingly focused on this region of the sky -- such as the recent discovery of 7 Earth-like worlds orbiting the Trappist-1 star in the Aquarius constellation -- will be an epochal 21st Century phenomenon of human science, society, and starlife.

  4. On Radiative Factors in Planetary Rings: New Insight Derived from Cassini CIRS Observations at Saturn Equinox

    NASA Astrophysics Data System (ADS)

    Brooks, S. M.; Spilker, L. J.; Pilorz, S.; Edgington, S. G.; Deau, E.; Morishima, R.

    2012-12-01

    Since arriving at Saturn in 2004, Cassini's Composite Infrared Spectrometer has recorded tens of millions of spectra of Saturn's rings (personal communication, M. Segura). CIRS records far infrared radiation (16.7-1000 microns) at focal plane 1 (FP1). Thermal emission from Saturn's rings peaks at FP1 wavelengths. CIRS spectra are well characterized as blackbody emission at an effective temperature Te, multiplied by a scalar factor related to ring emissivity (Spilker et al. [2005, 2006]). CIRS can therefore characterize the rings' temperature and study the thermal environment to which the ring particles are subject. We focus on CIRS data from the 2009 Saturnian equinox. As the Sun's disk crossed the ring plane, CIRS obtained several radial scans of the rings at a variety of phase angles, local hour angles and distances. With the Sun's rays striking the rings at an incidence angle of zero, solar heating is virtually absent, and thermal radiation from Saturn and sunlight reflected by Saturn dominate the thermal environment. These observations appear to present a paradox. Equinox data show that the flux of thermal energy radiated by the rings can even exceed the energy incident upon them as prescribed by thermal models, particularly in the C ring and Cassini Division (Ferrari and Leyrat [2006], Morishima et al. [2009, 2010]). Conservation principles suggest that such models underestimate heating of the rings in these cases, as it is clearly unphysical for the rings to radiate significantly more energy than is incident upon them. In this presentation, we will describe our efforts to resolve this paradox and determine what doing so can teach us about Saturn's rings. This research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under contract with NASA. Copyright 2012 California Institute of Technology. Government sponsorship acknowledged.

  5. VizieR Online Data Catalog: 33 RR Lyrae observed in Pisces with K2-E2 (Molnar+, 2015)

    NASA Astrophysics Data System (ADS)

    Molnar, L.; Szabo, R.; Moskalik, P. A.; Nemec, J. M.; Guggenberger, E.; Smolec, R.; Poleski, R.; Plachy, E.; Kolenberg, K.; Kollath, Z.

    2016-03-01

    Kepler observed a stellar field around the vernal equinox point in Pisces (centre coordinates: RA=359°, DE=-2°) between 2014 February 04 and 13. The primary goal of this K2 Two-Wheel Concept Engineering Test (hereafter K2-E2) was to test the performance of the telescope in fine guidance mode. As well, the observations of nearly 2000 targets were made available for the scientific community. We identified 33 potential RR Lyrae stars in the K2-E2 sample and extracted their photometric data with the pyke software, developed for the Kepler mission by the Kepler Guest Observer Office (Still & Barclay, 2012, Astrophysics Source Code Library record ascl:1208.004). (6 data files).

  6. In the Shadows of Ice and Sand: International Collaboration between Scientists and Students in the High Desert

    NASA Astrophysics Data System (ADS)

    Haste, T.; Baker, A.; Spindler, P.; McGann, M.

    2008-12-01

    Two middle school students in Albuquerque, New Mexico collaborated with staff of Amundsen-Scott South Pole and Palmer stations and the US Geological Survey to measure sun shadows. Students tested the phrase: "a location will experience longer shadows in winter and a shorter shadow in summer" through a collection of international data demonstrating seasonal solar angle variation. Measurements of the length of the sun's shadow were taken weekly at solar noon as cast from a one-meter stick placed at 90° from a flat surface. Students focused initially comparing their measurements taken between November and winter solstice to those taken concurrently by Antarctic station personnel. Viewing websites, blogs, sending e-mails, and placing a call to the team at the Amundsen-Scott South Pole Station, students learned about the different contributing locations. During the call, the shadow teams discussed the students' data summary, experimental problems, personal motivations for the team members to be at the pole, how they got started in their particular field, and their opinions on Climate Change. Winter solstice measurements ranged from 158 to 231 cm between the latitudes of 35 and 42° N. Southern latitudes reported a range of 87 to 202 cm between 64 and 90° S. The project expanded with international collaboration on vernal equinox and summer solstice. Project partners submitted data from locations in seven countries spanning both hemispheres. On the vernal equinox, measurements ranged from 29.8 cm near the Equator (American Samoa 14° S) to 0 cm at the South Pole. Northern measurements were taken in Egypt (30° N) of 64.7 cm, Norway (59° N) 164 cm and Russia (59° N) of 158 cm. One partner stated that he originally didn't expect much of a difference between Russia and Norway as they were not quite a degree apart, and was surprised by the data. Reflecting on what he learned, he commented, "I now understand the differences in a few degrees can make in the amount of

  7. Singular climatic activity at Equinox over Titan's dunefields as seen by CASSINI

    NASA Astrophysics Data System (ADS)

    Rodriguez, Sebastien; Le Mouélic, Stephane; Barnes, Jason W.; Charnay, Benjamin; Kok, Jasper F.; Lorenz, Ralph D.; Radebaugh, Jani; Cornet, Thomas; Bourgeois, Olivier; Lucas, Antoine; Rannou, Pascal; Griffith, Caitlin A.; Coustenis, Athena; Appéré, Thomas; Hirtzig, Mathieu; Sotin, Christophe; Soderblom, Jason M.; Brown, Robert H.; Bow, Jacob; Vixie, Graham

    2016-04-01

    Titan, the largest satellite of Saturn, is the only satellite in the solar system with a dense atmosphere. The close and continuous observations of Titan by the Cassini spacecraft, in orbit around Saturn since July 2004, bring us evidences that Titan troposphere and low stratosphere experience an exotic, but complete meteorological cycle similar to the Earth hydrological cycle, with hydrocarbons evaporation, condensation in clouds, and rainfall. Cassini monitoring campaigns also demonstrate that Titan's cloud coverage and climate vary with latitude. Titan's tropics, with globally weak meteorological activity and widespread dune fields, seem to be slightly more arid than the poles, where extensive and numerous liquid reservoirs and sustained cloud activity were discovered. Only a few tropo-spheric clouds have been observed at Titan's tropics during the southern summer [2-4]. As equinox was approaching (in August 2009), they occurred more frequently and appeared to grow in strength and size [5-7]. We present here the observation of intense brightening at Titan's tropics, very close to the equinox. These detec-tions were conducted with the Visual and Infrared Mapping Spectrometer [8] (VIMS) onboard Cassini. Figure 1 presents the VIMS color composite images of the three individual events detected so far, observed during the Titan's flybys T56 (22 May 2009), T65 (13 January 2010) and T70 (21 June 2010). T56, T65 and T70 observations show an intense and transient brightening of large regions very close to the equator, which all appear spectrally and morphologically different from all previous observed surface features or atmospheric phenomena. These events share in particular a strong brightening at wavelengths greater than 2 μm (especially at 5 μm), making them spectrally distinct from the few large storms observed near the equator. We will discuss the possibility that these singular events may have occurred very close to the surface, having a very local origin. We

  8. Effects of adopting new precession, nutation and equinox corrections on the terrestrial reference frame

    NASA Technical Reports Server (NTRS)

    Zhu, S. Y.; Mueller, I. I.

    1982-01-01

    The effect of adopting definitive precession and equinox corrections on the terrestrial reference frame was investigated. It is noted that the effect on polar motion is a diurnal periodic term with an amplitude increasing linearly in time whole on UT1 it is a linear term: general principles are given to determine the effects of small rotations of the frame of a conventional inertial reference system (CIS) on the frame of the conventional terrestrial reference system (CTS); seven CTS options are presented, one of which is necessary to accommodate such rotation. Accommodating possible future changes in the astronomical nutation is discussed. The effects of differences which may exist between the various CTS's and CIS's on Earth rotation parameters (ERP) and how these differences can be determined are examined. It is shown that the CTS differences can be determined from observations made at the same site. The CIS differences by comparing the ERP's are determined by the different techniques during the same time period.

  9. Effects of adopting new precession, nutation and equinox corrections on the terrestrial reference frame

    NASA Technical Reports Server (NTRS)

    Zhu, S. Y.; Mueller, I. I.

    1982-01-01

    The effects of adopting new definitive precession and equinox corrections on the terrestrial reference frame was investigated. It is noted that: (1) the effect on polar motion is a diurnal periodic term with an amplitude increasing linearly in time whole on UT1 it is a linear term; (2) general principles are given to determine the effects of small rotations of the frame of a conventional inertial reference system (CIS) on the frame of the conventional terrestrial reference system (CTS); (3) seven CTS options are presented, one of which is necessary to accommodate such rotation. Accommodating possible future changes in the astronomical nutation is discussed. The effects of differences which may exist between the various CTS's and CIS's on Earth rotation parameters (ERP) and how these differences can be determined are examined. It is shown that the CTS differences can be determined from observations made at the same site, while the CIS differences by comparing the ERP's determined by the different techniques during the same time period.

  10. The ice age cycle and the deglaciations: an application of nonlinear regression modelling

    NASA Astrophysics Data System (ADS)

    Dalgleish, A. N.; Boulton, G. S.; Renshaw, E.

    2000-03-01

    We have applied the nonlinear regression technique known as additivity and variance stabilisation (AVAS) to time series which reflect Earth's climate over the last 600 ka. AVAS estimates a smooth, nonlinear transform for each variable, under the assumption of an additive model. The Earth's orbital parameters and insolation variations have been used as regression variables. Analysis of the contribution of each variable shows that the deglaciations are characterised by periods of increasing obliquity and perihelion approaching the vernal equinox, but not by any systematic change in eccentricity. The magnitude of insolation changes also plays no role. By approximating the transforms we can obtain a future prediction, with a glacial maximum at 60 ka AP, and a subsequent obliquity and precession forced deglaciation.

  11. Towards an Understanding of Radiative Factors on Planetary Rings: a Perspective from Cassini CIRS Observations at Saturn Equinox

    NASA Astrophysics Data System (ADS)

    Brooks, Shawn M.; Spilker, L.; Edgington, S. G.; Déau, E.; Pilorz, S. H.

    2012-10-01

    Since arriving at Saturn in 2004, Cassini's Composite Infrared Spectrometer has recorded tens of millions of spectra of Saturn’s rings (personal communication, M. Segura). CIRS records far infrared radiation (16.7-1000 microns) at focal plane 1 (FP1). Thermal emission from Saturn’s rings peaks at FP1 wavelengths. CIRS spectra are well characterized as blackbody emission at an effective temperature Te, multiplied by a scalar factor related to ring emissivity (Spilker et al. [2005, 2006]). CIRS can therefore characterize the rings' temperature and study the thermal environment to which the ring particles are subject. We focus on CIRS data from the 2009 Saturnian equinox. As the Sun's disk crossed the ring plane, CIRS obtained several radial scans of the rings at a variety of phase angles, local hour angles and distances. With the Sun's rays striking the rings at an incidence angle of zero, solar heating is virtually absent, and thermal radiation from Saturn and sunlight reflected by Saturn dominate the thermal environment. These observations present an apparent paradox. Equinox data show that the flux of thermal energy radiated by the rings is roughly equivalent to or even exceeds the energy incident upon them as prescribed by thermal models (Froidevaux [1981], Ferrari and Leyrat [2006], Morishima et al. [2009, 2010]). This apparent energy excess is largest in the C ring and Cassini Division. Conservation principles suggest that models underestimate heating of the rings, as it is clearly unphysical for the rings to radiate significantly more energy than is incident upon them. In this presentation, we will attempt to resolve this paradox and determine what this can teach us about Saturn's rings. This research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under contract with NASA. Copyright 2012 California Institute of Technology. Government sponsorship acknowledged.

  12. Copy Number Variation Affecting the Photoperiod-B1 and Vernalization-A1 Genes Is Associated with Altered Flowering Time in Wheat (Triticum aestivum)

    PubMed Central

    Isaac, Peter; Laurie, David A.

    2012-01-01

    The timing of flowering during the year is an important adaptive character affecting reproductive success in plants and is critical to crop yield. Flowering time has been extensively manipulated in crops such as wheat (Triticum aestivum L.) during domestication, and this enables them to grow productively in a wide range of environments. Several major genes controlling flowering time have been identified in wheat with mutant alleles having sequence changes such as insertions, deletions or point mutations. We investigated genetic variants in commercial varieties of wheat that regulate flowering by altering photoperiod response (Ppd-B1 alleles) or vernalization requirement (Vrn-A1 alleles) and for which no candidate mutation was found within the gene sequence. Genetic and genomic approaches showed that in both cases alleles conferring altered flowering time had an increased copy number of the gene and altered gene expression. Alleles with an increased copy number of Ppd-B1 confer an early flowering day neutral phenotype and have arisen independently at least twice. Plants with an increased copy number of Vrn-A1 have an increased requirement for vernalization so that longer periods of cold are required to potentiate flowering. The results suggest that copy number variation (CNV) plays a significant role in wheat adaptation. PMID:22457747

  13. Pre- and Post-equinox ROSINA production rates calculated using a realistic empirical coma model derived from AMPS-DSMC simulations of comet 67P/Churyumov-Gerasimenko

    NASA Astrophysics Data System (ADS)

    Hansen, Kenneth; Altwegg, Kathrin; Berthelier, Jean-Jacques; Bieler, Andre; Calmonte, Ursina; Combi, Michael; De Keyser, Johan; Fiethe, Björn; Fougere, Nicolas; Fuselier, Stephen; Gombosi, Tamas; Hässig, Myrtha; Huang, Zhenguang; Le Roy, Lena; Rubin, Martin; Tenishev, Valeriy; Toth, Gabor; Tzou, Chia-Yu

    2016-04-01

    We have previously used results from the AMPS DSMC (Adaptive Mesh Particle Simulator Direct Simulation Monte Carlo) model to create an empirical model of the near comet coma (<400 km) of comet 67P for the pre-equinox orbit of comet 67P/Churyumov-Gerasimenko. In this work we extend the empirical model to the post-equinox, post-perihelion time period. In addition, we extend the coma model to significantly further from the comet (~100,000-1,000,000 km). The empirical model characterizes the neutral coma in a comet centered, sun fixed reference frame as a function of heliocentric distance, radial distance from the comet, local time and declination. Furthermore, we have generalized the model beyond application to 67P by replacing the heliocentric distance parameterizations and mapping them to production rates. Using this method, the model become significantly more general and can be applied to any comet. The model is a significant improvement over simpler empirical models, such as the Haser model. For 67P, the DSMC results are, of course, a more accurate representation of the coma at any given time, but the advantage of a mean state, empirical model is the ease and speed of use. One application of the empirical model is to de-trend the spacecraft motion from the ROSINA COPS and DFMS data (Rosetta Orbiter Spectrometer for Ion and Neutral Analysis, Comet Pressure Sensor, Double Focusing Mass Spectrometer). The ROSINA instrument measures the neutral coma density at a single point and the measured value is influenced by the location of the spacecraft relative to the comet and the comet-sun line. Using the empirical coma model we can correct for the position of the spacecraft and compute a total production rate based on the single point measurement. In this presentation we will present the coma production rate as a function of heliocentric distance both pre- and post-equinox and perihelion.

  14. The Periodic Flapping and Breathing of Saturn's Magnetodisk During Equinox

    NASA Astrophysics Data System (ADS)

    Sorba, A. M.; Achilleos, N.; Guio, P.; Arridge, C. S.; Dougherty, M. K.; Sergis, N.

    2017-12-01

    Periodic variations have been observed in many field and particle properties in Saturn's magnetosphere, modulated at a period close to the planetary rotation rate. Magnetic field observations by Cassini's magnetometer instrument suggest that in the outer magnetosphere (beyond 12 Saturn radii) Saturn's current sheet is periodically displaced with respect to the rotational equator, to a first approximation acting as a rotating, tilted disk. This manifests as a `flapping' mode when observed by the spacecraft. Recent studies suggest the magnetosphere also has a `breathing' mode, expanding and contracting with a period close to the planetary rotation rate. We model these two modes in tandem by combining a global, geometrical model of a tilted and rippled current sheet with a local, force-balance model of Saturn's magnetodisk, accounting for the magnetospheric size and hot plasma content. We simulate the breathing behavior by introducing an azimuthal dependence of the system size. We fit Cassini magnetometer data acquired on equatorial orbits from 23 Oct - 17 Dec 2009 (Revs 120-122), close to Saturn equinox, in order that seasonal effects on the current sheet are minimised. We find that our model characterises well the amplitude and phase of the oscillations in the data, for those passes that show clear periodic signatures in the field. In particular, the Bθ (meridional) component can only be characterised when the breathing mode is included. This study introduces calculations for an oscillating boundary under conditions of constant solar wind dynamic pressure, which provide a good basis for understanding the complex relationship between current sheet dynamics and the periodic field perturbations.

  15. A Tourist-like MITE insertion in the upstream region of the BnFLC.A10 gene is associated with vernalization requirement in rapeseed (Brassica napus L.).

    PubMed

    Hou, Jinna; Long, Yan; Raman, Harsh; Zou, Xiaoxiao; Wang, Jing; Dai, Shutao; Xiao, Qinqin; Li, Cong; Fan, Longjiang; Liu, Bin; Meng, Jinling

    2012-12-15

    Rapeseed (Brassica napus L.) has spring and winter genotypes adapted to different growing seasons. Winter genotypes do not flower before the onset of winter, thus leading to a longer vegetative growth period that promotes the accumulation and allocation of more resources to seed production. The development of winter genotypes enabled the rapeseed to spread rapidly from southern to northern Europe and other temperate regions of the world. The molecular basis underlying the evolutionary transition from spring- to winter- type rapeseed is not known, however, and needs to be elucidated. We fine-mapped the spring environment specific quantitative trait locus (QTL) for flowering time, qFT10-4,in a doubled haploid (DH) mapping population of rapeseed derived from a cross between Tapidor (winter-type) and Ningyou7 (semi-winter) and delimited the qFT10-4 to an 80-kb region on chromosome A10 of B. napus. The BnFLC.A10 gene, an ortholog of FLOWERING LOCUS C (FLC) in Arabidopsis, was cloned from the QTL. We identified 12 polymorphic sites between BnFLC.A10 parental alleles of the TN-DH population in the upstream region and in intron 1. Expression of both BnFLC.A10 alleles decreased during vernalization, but decreased more slowly in the winter parent Tapidor. Haplotyping and association analysis showed that one of the polymorphic sites upstream of BnFLC.A10 is strongly associated with the vernalization requirement of rapeseed (r2 = 0.93, χ2 = 0.50). This polymorphic site is derived from a Tourist-like miniature inverted-repeat transposable element (MITE) insertion/deletion in the upstream region of BnFLC.A10. The MITE sequence was not present in the BnFLC.A10 gene in spring-type rapeseed, nor in ancestral 'A' genome species B. rapa genotypes. Our results suggest that the insertion may have occurred in winter rapeseed after B. napus speciation. Our findings strongly suggest that (i) BnFLC.A10 is the gene underlying qFT10-4, the QTL for phenotypic diversity of flowering time in

  16. Ten Years of Vegetation Change in Northern California Marshlands Detected using Landsat Satellite Image Analysis

    NASA Technical Reports Server (NTRS)

    Potter, Christopher

    2013-01-01

    The Landsat Ecosystem Disturbance Adaptive Processing System (LEDAPS) methodology was applied to detected changes in perennial vegetation cover at marshland sites in Northern California reported to have undergone restoration between 1999 and 2009. Results showed extensive contiguous areas of restored marshland plant cover at 10 of the 14 sites selected. Gains in either woody shrub cover and/or from recovery of herbaceous cover that remains productive and evergreen on a year-round basis could be mapped out from the image results. However, LEDAPS may not be highly sensitive changes in wetlands that have been restored mainly with seasonal herbaceous cover (e.g., vernal pools), due to the ephemeral nature of the plant greenness signal. Based on this evaluation, the LEDAPS methodology would be capable of fulfilling a pressing need for consistent, continual, low-cost monitoring of changes in marshland ecosystems of the Pacific Flyway.

  17. Study of the Light Received Characteristics of a Plant-Shoot-Light-Condensing System with Simple Leaves or Lobed Leaves

    NASA Astrophysics Data System (ADS)

    Obara, Shin'ya

    Plant shoot configurations evolve so that maximum sunlight may be obtained. The objective of this study is to develop a compact light-condensing system mimicking a plant shoot configuration that is applicable to a light source from a large area. In this paper, the relationship between the position of a light source (the sun) and the rate at which light is absorbed by each leaf was investigated in detail for plant shoot models of a dogwood (simple leaf) and a ginkgo tree (lobed leaf). The rate of light quantum received in each leaf model is reported to an analysis program that uses cross entropy (CE). The analyses showed that the peak amount of light received in the plant-shoot-light-condensing system was during February (vernal equinox) and October (autumnal equinox). Similarly, the rate of light quantum received in each leaf was measured with the CE. The results found that the plant-shoot-light-condensing system that maximizes the amount of light received has differences in the light received in each leaf. Furthermore, the light-condensing characteristics of the ginkgo biloba model are better than the dogwood model. The light-condensing characteristics of a leaf are influenced by the size, a lobe, shape, and the length of the branch.

  18. Snow in northeastern United States

    NASA Image and Video Library

    2014-03-11

    Snow covered the northeastern United States on last day of meteorological winter, 2014. Climatologists and meteorologists break seasons down into three-month groups, based on annual temperature and our calendar. This method is helpful for weather observing and forecasting, and for planning consistent agricultural dates, such as expected first frosts or best planting date. Meteorological winter – the season where temperatures are, on average, coldest and when snow is most likely to fall – runs from December 1 to February 28 in the United States and Canada. Winter can also be defined by the astronomical calendar, which is based on the rotation of the Earth around the sun. In this method, the seasons are defined by two solstices (times when the sun’s path is furthest from the Earth’s equator) and two equinoxes (the times when the sun passes directly above the equator). In the Northern Hemisphere, winter begins on the winter solstice, which falls on or around December 22 and ends on or around March 21, at the vernal (spring) equinox. On February 28, 2014, the Moderate Resolution Imaging Spectroradiometer aboard NASA’s Aqua satellite captured this true-color image of a sunny winter day in the northeastern United States. Snow stretches from Maine west to Indiana and south along the ridges of the Appalachian Mountains well into West Virginia. In Canada, the landscape appears greener, primarily because snow lies on conifers (evergreen) trees in the boreal forest regions. The Great Lakes, with the exception of Lake Ontario, are almost completely covered with ice. Credit: NASA/GSFC/Jeff Schmaltz/MODIS Land Rapid Response Team NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on

  19. Effects of vernal and allergic conjunctivitis on severity of keratoconus.

    PubMed

    Cingu, Abdullah Kursat; Cinar, Yasin; Turkcu, Fatih Mehmet; Sahin, Alparslan; Ari, Seyhmus; Yuksel, Harun; Sahin, Muhammed; Caca, Ihsan

    2013-01-01

    To demonstrate the effects of two different types of allergic conjunctivitis on severity of keratoconus (KC). We retrospectively reviewed the medical records of 171 KC patients referred between June 2010 and June 2011. The KC patients were divided into 3 groups as KC (group A), KC with vernal keratoconjunctivitis (VKC) (group B) and KC with allergic conjunctivitis (AC) (group C). Main outcome measures were demographic and ocular clinical features including age at presentation, gender, spherical equivalent (SE), best spectacle corrected visual acuity (BCVA), mean keratometric measurement (Km), central corneal thickness (CCT), and intraocular pressure (IOP). Groups were compared in term of study variables. The median age at presentation was significantly lower in group B (P<0.001). According to the median SE (P=0.003), BCVA (P=0.022), Km (P<0.001), CCT (P=0.015) and Amsler-Krumeich classification (P<0.001), KC was more severe in group B. There was no significant difference in terms of IOP and corrected IOP among the groups (P=0.44), however there were 4 patients who had increased corrected IOP developed after topical corticosteroid use in group B. The differences among the groups persisted even after controlling for age and gender. Our findings demonstrated a more severe KC in VKC patients despite their younger age which suggests evaluation of VKC patients as a separate group in keratoconus disease.

  20. Characteristics of the equatorial plasma drifts as obtained by using Canadian Doppler ionosonde over southern tip of India

    NASA Astrophysics Data System (ADS)

    Sripathi, S.; Singh, Ram; Banola, S.; Sreekumar, Sreeba; Emperumal, K.; Selvaraj, C.

    2016-08-01

    We present here characteristics of the Doppler drift measurements over Tirunelveli (8.73°N, 77.70°E; dip 0.5°N), an equatorial site over Southern India using Doppler interferometry technique of Canadian ionosonde. Three-dimensional bulk motions of the scatterers as reflected from the ionosphere are derived by using Doppler interferometry technique at selected frequencies using spaced receivers arranged in magnetic E-W and N-S directions. After having compared with Lowell's digisonde drifts at Trivandrum, we studied the temporal and seasonal variabilities of quiet time drifts for the year 2012. The observations showed higher vertical drifts during post sunset in the equinox followed by winter and summer seasons. The comparison of Doppler vertical drifts with the drifts obtained from (a) virtual height and (b) Fejer drift model suggests that Doppler vertical drifts are relatively higher as compared to the drifts obtained from model and virtual height methods. Further, it is seen that vertical drifts exhibited equinoctial asymmetry in prereversal enhancement quite similar to such asymmetry observed in the spread F in the ionograms and GPS L band scintillations. The zonal drifts, on the other hand, showed westward during daytime with mean drifts of ~150-200 m/s and correlated well with equatorial electrojet strength indicating the role of E region dynamo during daytime, while they are eastward during nighttime with mean drifts of ~100 m/s resembling F region dynamo process. Also, zonal drifts showed large westward prior to the spread F onset during autumn equinox than vernal equinox, suggesting strong zonal shears which might cause equinoctial asymmetry in spread F.

  1. When Will It Be... USNO Seasons and Apsides Calculator

    NASA Astrophysics Data System (ADS)

    Chizek Frouard, Malynda; Bartlett, Jennifer Lynn

    2018-01-01

    The turning of the Earth’s seasons (solstices and equinoxes) and apsides (perihelions and aphelions) are times often used in observational astronomy and also of interest to the public. To avoid tedious calculations, the U.S. Naval Observatory (USNO) has developed an on-line interactive calculator, Earth’s Seasons and Apsides to provide information about events between 1600 and 2200. The new data service uses an Application Programming Interface (API), which returns values in JavaScript Object Notation (JSON) that can be incorporated into third-party websites or applications. For a requested year, the Earth’s Seasons and Apsides API provides the Gregorian calendar date and time of the Vernal Equinox, Summer Solstice, Autumnal Equinox, Winter Solstice, Aphelion, and Perihelion. The user may specify the time zone for their results, including the optional addition of U.S. daylight saving time for years after 1966.On-line documentation for using the API-enabled Earth’s Seasons and Apsides is available, including sample calls (http://aa.usno.navy.mil/data/docs/api.php). A traditional forms-based interface is available as well (http://aa.usno.navy.mil/data/docs/EarthSeasons.php). This data service replaces the popular Earth's Seasons: Equinoxes, Solstices, Perihelion, and Aphelion page that provided a static list of events for 2000–2025. The USNO also provides API-enabled data services for Complete Sun and Moon Data for One Day (http://aa.usno.navy.mil/data/docs/RS_OneDay.php), Dates of the Primary Phases of the Moon (http://aa.usno.navy.mil/data/docs/MoonPhase.php), Selected Christian Observances (http://aa.usno.navy.mil/data/docs/easter.php), Selected Islamic Observances (http://aa.usno.navy.mil/data/docs/islamic.php), Selected Jewish Observances (http://aa.usno.navy.mil/data/docs/passover.php), Julian Date Conversion (http://aa.usno.navy.mil/data/docs/JulianDate.php), and Sidereal Time (http://aa.usno.navy.mil/data/docs/siderealtime.php) as well as its Solar

  2. Large-scale gravity wave perturbations in the mesopause region above Northern Hemisphere midlatitudes during autumnal equinox: a joint study by the USU Na lidar and Whole Atmosphere Community Climate Model

    NASA Astrophysics Data System (ADS)

    Cai, X.

    2017-12-01

    To investigate gravity wave (GW) perturbations in the midlatitude mesopause region during boreal equinox, 433 h of continuous Na lidar full diurnal cycle temperature measurements in September between 2011 and 2015 are utilized to derive the monthly profiles of GW-induced temperature variance, T'^2, and the potential energy density (PED). Operating at Utah State University (42° N, 112° W), these lidar measurements reveal severe GW dissipation near 90 km, where both parameters drop to their minima (˜ 20 K^2 and ˜ 50 m^2/ s^2, respectively). The study also shows that GWs with periods of 3-5 h dominate the midlatitude mesopause region during the summer-winter transition. To derive the precise temperature perturbations a new tide removal algorithm suitable for all ground-based observations is developed to de-trend the lidar temperature measurements and to isolate GW-induced perturbations. It removes the tidal perturbations completely and provides the most accurate GW perturbations for the ground-based observations. This algorithm is validated by comparing the true GW perturbations in the latest mesoscale-resolving Whole Atmosphere Community Climate Model (WACCM) with those derived from the WACCM local outputs by applying this newly developed tidal removal algorithm.

  3. Near-equinox spectro-imaging of Uranus aurorae sampling two planetary rotations

    NASA Astrophysics Data System (ADS)

    Lamy, Laurent

    2012-10-01

    A quarter of century after their discovery by Voyager 2 in 1986, HST sucessfully re-detected Uranus aurorae in 2011 {and also in 1998}, providing the first images of these emissions. Overall, they differ from other well-known planetary aurorae, and their characteristics vary at very different timescales, from minutes to decades. These results have provided the first insights on the poorly known Uranian magnetosphere in 26 years, and opened a rich field of investigation, together with a set of open questions. In addition, while solstice conditions prevailed in 1986, Uranus lay close to equinox in 2011, with the S and N magnetic poles alternately facing the Sun every half a rotation. This unique configuration of an asymmetric magnetosphere, extremely variable over a single rotation, had never been investigated before and deserved to be fully analyzed. New observations of the Uranian aurorae are therefore vital for our understanding of planetary magnetospheres, and HST is the only tool able to remotely investigate these emissions. We thus propose to re-observe Uranus with STIS spectro-imaging at next opposition {29 Sept. 2012} over two planetary rotations, in order to enlarge the set of positive detections and to sample the rotational dynamics of auroral processes and magnetosphere/solar wind interaction. To increase the probability of any possible auroral brightening triggered by magnetospheric compressions, observations will be scheduled in advance during active solar wind conditions at Uranus, near the maximum of solar cycle 24. Additional objectives will include the characterization of the extended neutral corona and the spectral response of atmospheric species.

  4. Effects of vernal and allergic conjunctivitis on severity of keratoconus

    PubMed Central

    Cingu, Abdullah Kursat; Cinar, Yasin; Turkcu, Fatih Mehmet; Sahin, Alparslan; Ari, Seyhmus; Yuksel, Harun; Sahin, Muhammed; Caca, Ihsan

    2013-01-01

    AIM To demonstrate the effects of two different types of allergic conjunctivitis on severity of keratoconus (KC). METHODS We retrospectively reviewed the medical records of 171 KC patients referred between June 2010 and June 2011. The KC patients were divided into 3 groups as KC (group A), KC with vernal keratoconjunctivitis (VKC) (group B) and KC with allergic conjunctivitis (AC) (group C). Main outcome measures were demographic and ocular clinical features including age at presentation, gender, spherical equivalent (SE), best spectacle corrected visual acuity (BCVA), mean keratometric measurement (Km), central corneal thickness (CCT), and intraocular pressure (IOP). Groups were compared in term of study variables. RESULTS The median age at presentation was significantly lower in group B (P<0.001). According to the median SE (P=0.003), BCVA (P=0.022), Km (P<0.001), CCT (P=0.015) and Amsler–Krumeich classification (P<0.001), KC was more severe in group B. There was no significant difference in terms of IOP and corrected IOP among the groups (P=0.44), however there were 4 patients who had increased corrected IOP developed after topical corticosteroid use in group B. The differences among the groups persisted even after controlling for age and gender. CONCLUSION Our findings demonstrated a more severe KC in VKC patients despite their younger age which suggests evaluation of VKC patients as a separate group in keratoconus disease. PMID:23826535

  5. Changes in atmospheric composition inferred from ionospheric production rates

    NASA Technical Reports Server (NTRS)

    Titheridge, J. E.

    1974-01-01

    Changes in the total electron content of the ionosphere near sunrise are used to determine the integrated production rate in the ionosphere (Q) from 1965 to 1971 at latitudes of 34S, 20N, and 34N. The observed regular semiannual variation in Q through a range of 1:3:1 is interpreted as an increase in the ratio O/N2 (relative densities) near the equinoxes. It follows that there is a worldwide semiannual variation in atmospheric composition, with the above ratio maximum just after the equinoxes. There is a large seasonal variation in the Northern hemisphere with a maximum in mid-summer. This effect is absent in the Southern hemisphere. At all times except solar maximum in the Northern hemisphere there is a global asymmetry. The ratio O/N2 is about three times as large in the Northern hemisphere. The overall mechanism appears to be N2 absorption.

  6. The occurrence of glyphosate, atrazine, and other pesticides in vernal pools and adjacent streams in Washington, DC, Maryland, Iowa, and Wyoming, 2005-2006

    USGS Publications Warehouse

    Battaglin, William A.; Rice, Karen C.; Focazio, Michael J.; Salmons, Sue; Barry, Robert X.

    2009-01-01

    Vernal pools are sensitive environments that provide critical habitat for many species, including amphibians. These small water bodies are not always protected by pesticide label requirements for no-spray buffer zones, and the occurrence of pesticides in them is poorly documented. In this study, we investigated the occurrence of glyphosate, its primary degradation product aminomethylphosphonic acid, and additional pesticides in vernal pools and adjacent flowing waters. Most sampling sites were chosen to be in areas where glyphosate was being used either in production agriculture or for nonindigenous plant control. The four site locations were in otherwise protected areas (e.g., in a National Park). When possible, water samples were collected both before and after glyphosate application in 2005 and 2006. Twenty-eight pesticides or pesticide degradation products were detected in the study, and as many as 11 were identified in individual samples. Atrazine was detected most frequently and concentrations exceeded the freshwater aquatic life standard of 1.8 micrograms per liter (μg/l) in samples from Rands Ditch and Browns Ditch in DeSoto National Wildlife Refuge. Glyphosate was measured at the highest concentration (328 μg/l) in a sample from Riley Spring Pond in Rock Creek National Park. This concentration exceeded the freshwater aquatic life standard for glyphosate of 65 μg/l. Aminomethylphosphonic acid, triclopyr, and nicosulfuron also were detected at concentrations greater than 3.0 μg/l.

  7. A Tourist-like MITE insertion in the upstream region of the BnFLC.A10 gene is associated with vernalization requirement in rapeseed (Brassica napus L.)

    PubMed Central

    2012-01-01

    Background Rapeseed (Brassica napus L.) has spring and winter genotypes adapted to different growing seasons. Winter genotypes do not flower before the onset of winter, thus leading to a longer vegetative growth period that promotes the accumulation and allocation of more resources to seed production. The development of winter genotypes enabled the rapeseed to spread rapidly from southern to northern Europe and other temperate regions of the world. The molecular basis underlying the evolutionary transition from spring- to winter- type rapeseed is not known, however, and needs to be elucidated. Results We fine-mapped the spring environment specific quantitative trait locus (QTL) for flowering time, qFT10-4,in a doubled haploid (DH) mapping population of rapeseed derived from a cross between Tapidor (winter-type) and Ningyou7 (semi-winter) and delimited the qFT10-4 to an 80-kb region on chromosome A10 of B. napus. The BnFLC.A10 gene, an ortholog of FLOWERING LOCUS C (FLC) in Arabidopsis, was cloned from the QTL. We identified 12 polymorphic sites between BnFLC.A10 parental alleles of the TN-DH population in the upstream region and in intron 1. Expression of both BnFLC.A10 alleles decreased during vernalization, but decreased more slowly in the winter parent Tapidor. Haplotyping and association analysis showed that one of the polymorphic sites upstream of BnFLC.A10 is strongly associated with the vernalization requirement of rapeseed (r2 = 0.93, χ2 = 0.50). This polymorphic site is derived from a Tourist-like miniature inverted-repeat transposable element (MITE) insertion/deletion in the upstream region of BnFLC.A10. The MITE sequence was not present in the BnFLC.A10 gene in spring-type rapeseed, nor in ancestral ‘A’ genome species B. rapa genotypes. Our results suggest that the insertion may have occurred in winter rapeseed after B. napus speciation. Conclusions Our findings strongly suggest that (i) BnFLC.A10 is the gene underlying qFT10-4, the QTL for

  8. The control net of Mars - May 1977. [from Viking lander spacecraft radio tracking data

    NASA Technical Reports Server (NTRS)

    Davies, M. E.

    1978-01-01

    The development of planet-wide control nets of Mars is reviewed, and the May 1977 update is described. This updated control net was computed by means of a large single-block analytical triangulation incorporating the new direction of the spin axis and the new rotation rate of Mars, as determined from radio tracking data provided by the Viking lander spacecraft. The analytical triangulation adjusts for planimetric control only (areocentric latitude and longitude) and for the camera orientation angles. Most of the areocentric radii at the control points were interpolated from radio occultation measurements, but a few were determined photogrammetically, and a substantial number were derived from elevation contours on the 1976 USGS topographic series of Mars maps. A value of V, measured from Mars' vernal equinox along the equator to the prime meridian (Airy-0) is presented.

  9. Effect of local and global geomagnetic activity on human cardiovascular homeostasis.

    PubMed

    Dimitrova, Svetla; Stoilova, Irina; Yanev, Toni; Cholakov, Ilia

    2004-02-01

    The authors investigated the effects of local and planetary geomagnetic activity on human physiology. They collected data in Sofia, Bulgaria, from a group of 86 volunteers during the periods of the autumnal and vernal equinoxes. They used the factors local/planetary geomagnetic activity, day of measurement, gender, and medication use to apply a four-factor multiple analysis of variance. They also used a post hoc analysis to establish the statistical significance of the differences between the average values of the measured physiological parameters in the separate factor levels. In addition, the authors performed correlation analysis between the physiological parameters examined and geophysical factors. The results revealed that geomagnetic changes had a statistically significant influence on arterial blood pressure. Participants expressed this reaction with weak local geomagnetic changes and when major and severe global geomagnetic storms took place.

  10. Effects of the equatorial ionosphere on L-band Earth-space transmissions

    NASA Technical Reports Server (NTRS)

    Smith, Ernest K.; Flock, Warren L.

    1993-01-01

    Ionosphere scintillation can effect satellite telecommunication up to Ku-band. Nighttime scintillation can be attributed to large-scale inhomogeneity in the F-region of the ionosphere predominantly between heights of 200 and 600 km. Daytime scintillation has been attributed to sporadic E. It can be thought of as occurring in three belts: equatorial, high-latitude, and mid-latitude, in order of severity. Equatorial scintillation occurs between magnetic latitudes +/- 25 degrees, peaking near +/- 10 degrees. It commonly starts abruptly near 2000 local time and dies out shortly after midnight. There is a strong solar cycle dependence and a seasonal preference for the equinoxes, particularly the vernal one. Equatorial scintillation occurs more frequently on magnetically quiet than on magnetically disturbed days in most longitudes. At the peak of the sunspot cycle scintillation depths as great as 20 dB were observed at L-band.

  11. Increased incidence of thyroid dysfunction and autoimmunity in patients with vernal keratoconjunctivitis.

    PubMed

    Stagi, Stefano; Pucci, Neri; Di Grande, Laura; de Libero, Cinzia; Caputo, Roberto; Pantano, Stefano; Mattei, Ivan; Mori, Francesca; de Martino, Maurizio; Novembre, Elio

    2014-01-01

    Hormones may play a role in the pathophysiology of vernal keratoconjunctivitis (VKC). An increased incidence of thyroid autoantibodies was recently observed in VKC, although there were no data on thyroid function. Two hundred and eighty-eight patients (202 males, 86 females; range 5.5 to 16.9 years) with VKC were evaluated and compared with 188 normal age- and sex-matched subjects. In all subjects, serum concentrations of free T4, TSH, thyroperoxidase, thyroglobulin, and TSHr autoantibodies were evaluated. In VKC, the family history of thyroid diseases showed no significant differences compared to the controls (9.4 versus 8.6%), whereas the family history of autoimmune diseases was significantly higher (13.2% versus 6.3%; P<0.05). Subclinical hypothyroidism was diagnosed in 6.6% (versus 1.6% of the controls; P<0.05) and overt hypothyroidism in 0.7% (versus 0.0% of the controls; P = NS). Finally, 5.2% of patients were positive for thyroid autoantibodies, which were significantly higher with respect to the controls (0.5%, P<0.05). In the patients positive for thyroid autoantibodies, 80% showed a sonography pattern that suggested autoimmune thyroiditis. Thyroid function and autoimmunity abnormalities are frequently present in children with VKC. Children with VKC should be screened for thyroid function and evaluated for thyroid autoimmunity.

  12. Seasonal Variations in Titan's Stratosphere Observed with Cassini/CIRS: Temperature, Trace Molecular Gas and Aerosol Mixing Ratio Profiles

    NASA Technical Reports Server (NTRS)

    Vinatier, S.; Bezard, B.; Anderson, C. M.; Coustenis, A.; Teanby, N.

    2012-01-01

    Titan's northern spring equinox occurred in August 2009. General Circulation Models (e.g. Lebonnois et al., 2012) predict strong modifications of the global circulation in this period, with formation of two circulation cells instead of the pole-to-pole cell that occurred during northern winter. This winter single cell, which had its descending branch at the north pole, was at the origin of the enrichment of molecular abundances and high stratopause temperatures observed by Cassini/CIRS at high northern latitudes (e.g. Achterberg et al., 2011, Coustenis et al., 2010, Teanby et al., 2008, Vinatier et al., 2010). The predicted dynamical seasonal variations after the equinox have strong impact on the spatial distributions of trace gas, temperature and aerosol abundances. We will present here an analysis of CIRS limb-geometry datasets acquired in 2010 and 2011 that we used to monitor the seasonal evolution of the vertical profiles of temperature, molecular (C2H2, C2H6, HCN, ..) and aerosol abundances.

  13. Main Ionospheric Trough and Equatorial Ionization Anomaly During Substorms With the Different UT Onset Moments

    NASA Astrophysics Data System (ADS)

    Klimenko, M. V.; Klimenko, V. V.; Bryukhanov, V. V.

    2007-05-01

    In the given work the numerical calculation results of ionospheric effects of four modeling substorms which have begun in 00, 06, 12 and 18 UT are presented. Calculations are executed on the basis of Global Self-consistent Model of the Thermosphere, Ionosphere and Protonosphere (GSM TIP), developed in WD IZMIRAN, added by the new block of calculation of electric fields in the ionosphere of the Earth for vernal equinox conditions in the minimum of solar activity. In calculations we considered superposition of magnetospheric convection electric field (at set potential differences through polar caps and field aligned currents of the second zone with taking into account of particle precipitation) and dynamo field generated by thermospheric winds without taking into account the tides. It is shown, that in the given statement of problem the substorms cause strong positive disturbances in F-region of ionosphere in night sector. Negative disturbances are much less and arise, mainly, at night in the middle and low latitudes. During substorms longitudinal extent of main ionospheric trough increases. The substorm beginning in 18 UT, causes negative disturbances in high latitudes except for a southern polar cap. Besides there is "stratification" of the main ionospheric trough. As a result in southern hemisphere the additional high-latitude trough which is absent in quiet conditions is formed. "Stratification" of the main ionospheric trough occurs in northern hemisphere at 6 hours after the beginning of the substorm. These "stratifications" are consequence non-stationary magnetospheric convection. Distinction between these events consists that "stratification" in a southern hemisphere occurs in active phase of substorm, and in northern hemisphere in recovery phase. During a substorm beginning in 00 UT, foF2 increases in all northern polar cap. Positive disturbances of foF2 in the equatorial anomaly region cause all presented substorms, except for a substorm beginning in 18 UT

  14. Effect of vernal keratoconjunctivitis on vitreous depth in patients with keratoconus.

    PubMed

    Cingü, Abdullah Kürşat; Kaya, Savaş; Çınar, Yasin; Şahin, Muhammed; Türkçü, Fatih Mehmet; Yüksel, Harun; Murat, Mehmet; Çaça, İhsan

    2015-05-01

    The aim of this study was to comparatively evaluate the vitreous depth (VD) of keratoconic eyes in patients with or without vernal keratoconjunctivitis (VKC). Eighty eyes of 80 consecutive keratoconus (KC) patients and 40 emmetropic control subjects were enrolled. KC patients were divided into two groups according to accompanying VKC (VKC-KC group and KC group). Mean outcome measures were best-corrected visual acuity (BCVA), spherical equivalent (SE), mean keratometry (Km), intraocular pressure (IOP), and axial length (AL) and its components. The eyes with the highest Km were selected for statistical analysis for each participant. There were 50, 30, and 40 patients in the VKC-KC group, KC group, and control group respectively. The KC group and VKC-KC group were similar in BCVA, SE, Km, CCT, ACD, LT, and IOP (p>0.05). The mean ACD was significantly lower in the control group when compared with the KC group and VKC-KC group. The mean AL and VD were significantly higher in VKC-KC group than those of KC group and the control group, whereas similar in KC and control groups (p>0.05). In the current study we showed that VKC-associated KC patients have significantly longer AL and VD when compared with KC patients without VKC. Posterior segment elongation in VKC-KC group may be associated with the type IV collagen destruction due to chronic longstanding inflammation in VKC patients.

  15. Increased Incidence of Thyroid Dysfunction and Autoimmunity in Patients with Vernal Keratoconjunctivitis

    PubMed Central

    Stagi, Stefano; Pucci, Neri; Di Grande, Laura; de Libero, Cinzia; Caputo, Roberto; Pantano, Stefano; Mattei, Ivan; Mori, Francesca; de Martino, Maurizio; Novembre, Elio

    2014-01-01

    Hormones may play a role in the pathophysiology of vernal keratoconjunctivitis (VKC). An increased incidence of thyroid autoantibodies was recently observed in VKC, although there were no data on thyroid function. Two hundred and eighty-eight patients (202 males, 86 females; range 5.5 to 16.9 years) with VKC were evaluated and compared with 188 normal age- and sex-matched subjects. In all subjects, serum concentrations of free T4, TSH, thyroperoxidase, thyroglobulin, and TSHr autoantibodies were evaluated. In VKC, the family history of thyroid diseases showed no significant differences compared to the controls (9.4 versus 8.6%), whereas the family history of autoimmune diseases was significantly higher (13.2% versus 6.3%; P<0.05). Subclinical hypothyroidism was diagnosed in 6.6% (versus 1.6% of the controls; P<0.05) and overt hypothyroidism in 0.7% (versus 0.0% of the controls; P = NS). Finally, 5.2% of patients were positive for thyroid autoantibodies, which were significantly higher with respect to the controls (0.5%, P<0.05). In the patients positive for thyroid autoantibodies, 80% showed a sonography pattern that suggested autoimmune thyroiditis. Thyroid function and autoimmunity abnormalities are frequently present in children with VKC. Children with VKC should be screened for thyroid function and evaluated for thyroid autoimmunity. PMID:25140177

  16. Five Years of Monitoring Mars' Daytime Surface Temperatures (Animation)

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site] Animation

    This movie shows the daytime temperature of the surface of Mars as measured by the Thermal Emission Spectrometer instrument on NASA's Mars Global Surveyor orbiter. These temperatures clearly show the growth and retreat of the martian northern and southern polar ice caps. The caps grow in winter and are composed of carbon dioxide ice with temperatures as low as minus 125 degrees Celsius (minus 195 degrees Fahrenheit). In the summer the caps retreat to relatively small areas around the poles. The movie also demonstrates the large difference in temperatures between the northern hemisphere's summer (beginning when solar longitude, or Ls, is 90 degrees) and the southern hemisphere's summer (beginning when Ls is 270 degrees). This difference is because the orbit of Mars around the Sun is more elliptical than Earth's orbit. As on Earth, a hemisphere's summer is when that hemisphere is tilted toward the Sun, but on Mars, the planet's distance from the Sun varies much more than on Earth. Mars is closest to the Sun, and therefore warmest, during the southern summer season. In northern summer, when Mars' northern hemisphere is tilted toward the Sun, the planet is farther from the Sun.

    Seasons on Mars are determined by the position of Mars in its orbit around the Sun. The position is measured in degrees of solar longitude (Ls) around the orbit, beginning at 0 degrees Ls at the northern spring equinox, progressing to 90 degrees Ls at the start of northern summer, 180 degrees Ls at the fall equinox, 270 degrees Ls at the start of northern winter, and finally back to 360 degrees, or 0 degrees, Ls at the spring equinox.

    The Thermal Emission Spectrometer is operated by a team led at Arizona State University, Tempe. Mars Global Surveyor left Earth on Nov. 7, 1996, and began orbiting Mars on Sept. 12, 1997. JPL, a division of the California Institute of Technology, Pasadena, manages Mars Global Surveyor for

  17. Trajectories of inner and outer heliospheric spacecraft: Predicted through 1999

    NASA Technical Reports Server (NTRS)

    Parthasarathy, R.; King, Joseph H.

    1991-01-01

    Information is presented in tabular and graphical form on the trajectories of the international fleet of spacecraft that will be probing the far reaches of the heliosphere during the 1990s. In particular, the following spacecraft are addressed: Pioneer 10 and 11, Pioneer Venus Orbiter (PVO), Voyager 1 and 2, Galileo, Ulysses, Suisei, Sakigake, Giotto, International Cometary Explorer (ICE), and Interplanetary Monitoring Platform 8 (IMP 8). Yearly resolution listing of position information in inertial space are given for Pioneer and Voyager spacecraft from the times of their launches in the 1970s. One series of plots shows the radial distances, latitudes, and longitudes of the Pioneers and Voyagers. The solar ecliptic inertial coordinate system is used. In this system, the Z axis is normal to the ecliptic plane and the X axis is towards the first point of Aries (from Sun to Earth on the vernal equinox).

  18. Weather and Large-Scale Dust Activity during Martian Northern Spring and Summer

    NASA Astrophysics Data System (ADS)

    Kass, David M.; Kleinboehl, Armin; McCleese, Daniel J.; Schofield, John Tim; Smith, Michael D.; Heavens, Nicholas

    2016-10-01

    Observations from MCS, TES and THEMIS now span the northern spring and summer seasons (Ls 0° to 180°) of 10 consecutive Mars Years (MY 24 through MY 33). These observations show very similar behavior each year. However, there are also noticeable differences and clear signs of inter-annual variability. To best study the three datasets, we examine zonal mean observations of the lower atmosphere (50 Pa, or ~25 km). This region was selected to provide the best quality from all three instruments. We separate the daytime (afternoon) and nighttime (early morning) data in the analysis.The climate at these seasons is dominated by the aphelion cloud belt, and 50 Pa is often close to the peak opacities in the clouds. There is also a strong diurnal thermal tide signature throughout the season at this altitude. The overall behavior is a rapid cooling at the start of the year (as the dust from the dusty season sediments out of the atmosphere) over the the first ~30° of Ls. The coldest temperatures then last until about the solstice and are followed by a slow warming trend through most of the rest of the season. The last ~30° prior to the fall equinox show a more rapid warming trend and significant inter-annual variability. In about half of the years, there is a warming event of the 50 Pa temperatures in the second half of northern summer. The warming is the signature of dust being lofted above the boundary layer, into the lower atmosphere. Due to the relatively clear atmosphere overall, even modest amounts of dust will create noticeable temperature changes. The temperature signature of the dust is more pronounced in the northern hemisphere.

  19. Same concept…Different terms

    NASA Astrophysics Data System (ADS)

    Heafner, Joe

    2018-03-01

    Most introductory physics courses begin with the concept of an object (usually a particle) having a precise position or location in space (I will not address spacetime here) relative to something else, the origin of a three-dimensional coordinate system perhaps. My experience has been that physics students are inherently at home with this concept. In astronomy, we often begin by thinking about the sky. For the purposes of this article, I will simply define it as that which we see when we look away from Earth's surface. It appears almost as a two-dimensional plane, perhaps even a curved surface. When we look at something in the sky, we really have no sense of distance. Indeed, when astronomers need the "position" of a star or planet in the sky, the quantity is two dimensional. Because the sky appears to wrap around Earth, celestial positions can be given entirely by angular quantities. Astronomers use right ascension and declination, respectively, as analogs of terrestrial longitude and latitude. Right ascension is the angular distance eastward around the celestial equator (the projection of Earth's equator onto the celestial sphere) from the vernal equinox (where the celestial equator and the ecliptic intersect such that the Sun is moving from the Southern Hemisphere to the Northern Hemisphere) to the object and declination is the object's angular distance north or south of the celestial equator. So to an astronomer, for the purposes of aiming a telescope, position refers to a two-dimensional quantity because in the sky there is no direct sense of depth or distance.

  20. Solar activity variations of nocturnal thermospheric meridional winds over Indian longitude sector

    NASA Astrophysics Data System (ADS)

    Madhav Haridas, M. K.; Manju, G.; Arunamani, T.

    2016-09-01

    The night time F-layer base height information from ionosondes located at two equatorial stations Trivandrum (TRV 8.5°N, 77°E) and Sriharikota (SHAR 13.7°N, 80.2°E) spanning over two decades are used to derive the climatology of equatorial nocturnal Thermospheric Meridional Winds (TMWs) prevailing during High Solar Activity (HSA) and Low Solar Activity (LSA) epochs. The important inferences from the analysis are 1) Increase in mean equatorward winds observed during LSA compared to HSA during pre midnight hours; 25 m/s for VE (Vernal Equinox) and 20 m/s for SS (Summer Solstice), AE (autumnal Equinox) and WS (Winter Solstice). 2) Mean wind response to Solar Flux Unit (SFU) is established quantitatively for all seasons for pre-midnight hours; rate of increase is 0.25 m/s/SFU for VE, 0.2 m/s/SFU for SS and WS and 0.08 m/s/SFU for AE. 3) Theoretical estimates of winds for the two epochs are performed and indicate the role of ion drag forcing as a major factor influencing TMWs. 4) Observed magnitude of winds and rate of flux dependencies are compared to thermospheric wind models. 5) Equinoctial asymmetry in TMWs is observed for HSA at certain times, with more equatorward winds during AE. These observations lend a potential to parameterize the wind components and effectively model the winds, catering to solar activity variations.

  1. Vernal keratoconjunctivitis in school children in Rwanda and its association with socio-economic status: a population-based survey.

    PubMed

    Smedt, Stefan De; Nkurikiye, John; Fonteyne, Yannick; Hogewoning, Arjan; Esbroeck, Marjan Van; Bacquer, Dirk De; Tuft, Stephen; Gilbert, Clare; Delanghe, Joris; Kestelyn, Philippe

    2011-10-01

    Vernal keratoconjunctivitis (VKC) is an allergic eye disease and an important cause of hospital referral among children in Africa and Asia. Hospital-based studies have suggested a role for parasites in its pathogenesis. To determine the prevalence and risk factors for VKC in Central Africa, we conducted a nested population-based case control study in Rwanda, involving randomly selected primary schools from different environments (rural/urban) and climate. A prevalence of VKC of 4.0% (95% confidence interval 3.3-4.7%) was found among 3,041 children studied (participation rate 94.7%). The intestinal parasitic burden was not related to VKC. Besides hot dry climate (odds ratio [OR] = 1.5, P = 0.05) and male gender (OR = 1.7, P = 0.005), multivariate analysis identified higher economic status as a risk for VKC (OR = 1.4, P = 0.005). The effect on VKC of higher economic status appears not to act through differences in parasitic intestinal load.

  2. Vernal Keratoconjunctivitis in School Children in Rwanda and Its Association with Socio-Economic Status: A Population-Based Survey

    PubMed Central

    Smedt, Stefan De; Nkurikiye, John; Fonteyne, Yannick; Hogewoning, Arjan; Esbroeck, Marjan Van; Bacquer, Dirk De; Tuft, Stephen; Gilbert, Clare; Delanghe, Joris; Kestelyn, Philippe

    2011-01-01

    Vernal keratoconjunctivitis (VKC) is an allergic eye disease and an important cause of hospital referral among children in Africa and Asia. Hospital-based studies have suggested a role for parasites in its pathogenesis. To determine the prevalence and risk factors for VKC in Central Africa, we conducted a nested population-based case control study in Rwanda, involving randomly selected primary schools from different environments (rural/urban) and climate. A prevalence of VKC of 4.0% (95% confidence interval 3.3–4.7%) was found among 3,041 children studied (participation rate 94.7%). The intestinal parasitic burden was not related to VKC. Besides hot dry climate (odds ratio [OR] = 1.5, P = 0.05) and male gender (OR = 1.7, P = 0.005), multivariate analysis identified higher economic status as a risk for VKC (OR = 1.4, P = 0.005). The effect on VKC of higher economic status appears not to act through differences in parasitic intestinal load. PMID:21976577

  3. NmF2 and hmF2 measurements at 95° E and 127° E around the EIA northern crest during 2010-2014

    NASA Astrophysics Data System (ADS)

    Kalita, Bitap Raj; Bhuyan, Pradip Kumar; Yoshikawa, Akimasa

    2015-11-01

    The characteristics of the F2 layer parameters NmF2 and hmF2 over Dibrugarh (27.5° N, 95° E, 17° N geomagnetic, 43° dip) measured by a Canadian Advanced Digital Ionosonde (CADI) for the period of August 2010 to July 2014 are reported for the first time from this low mid-latitude station lying within the daytime peak of the longitudinal wave number 4 structure of equatorial anomaly (EIA) around the northern edge of anomaly crest. Equinoctial asymmetry is clearly observed at all solar activity levels whereas the midday winter anomaly is observed only during high solar activity years and disappears during the temporary dip in solar activity in 2013 but forenoon winter anomaly can be observed even at moderate solar activity. The NmF2/hmF2 variations over Dibrugarh are compared with that of Okinawa (26.5° N, 127° E, 17° N geomagnetic), and the eastward propagation speed of the wave number 4 longitudinal structure from 95° E to 127° E is estimated. The speed is found to be close to the theoretical speed of the wave number 4 (WN4) structure. The correlation of daily NmF2 over Dibrugarh and Okinawa with solar activity exhibits diurnal and seasonal variations. The highest correlation in daytime is observed during the forenoon hours in equinox. The correlation of daily NmF2 (linear or non-linear) with solar activity exhibits diurnal variation. A tendency for amplification with solar activity is observed in the forenoon and late evening period of March equinox and the postsunset period of December solstice. NmF2 saturation effect is observed only in the midday period of equinox. Non-linear variation of neutral composition at higher altitudes and variation of recombination rates with solar activity via temperature dependence may be related to the non-linear trend. The noon time maximum NmF2 over Dibrugarh exhibits better correlation with equatorial electrojet (EEJ) than with solar activity and, therefore, new low-latitude NmF2 index is proposed taking both solar

  4. The aurorae of Uranus past equinox

    NASA Astrophysics Data System (ADS)

    Lamy, L.

    2017-12-01

    The aurorae of Uranus were recently detected in the far ultraviolet with the Hubble Space Telescope (HST) providing a new, so far unique, means to remotely study the asymmetric Uranian magnetosphere from Earth. We analyze here two new HST Uranus campaigns executed in September 2012 and November 2014 with different temporal coverage and under variable solar wind conditions numerically predicted by three different MHD codes. Overall, the HST images taken with the Space Telescope Imaging Spectrograph reveal auroral emissions in three pairs of successive images (one pair acquired in 2012 and two in 2014), hence 6 additional auroral detections in total, including the most intense Uranian aurorae ever seen with HST. The detected emissions occur close the expected arrival of interplanetary shocks. They appear as extended spots at southern latitudes, rotating with the planet. They radiate 5-24 kR and 1.3-8.8 GW of ultraviolet emission from H2, last for tens of minutes and vary on timescales down to a few seconds. Fitting the 2014 observations with model auroral ovals constrains the longitude of the southern (northern) magnetic pole to 104+/-26deg (284+/-26deg) in the Uranian Longitude System. We suggest that the Uranian near-equinoctial aurorae are pulsed cusp emissions possibly triggered by large-scale magnetospheric compressions.

  5. The aurorae of Uranus past equinox

    NASA Astrophysics Data System (ADS)

    Lamy, L.; Prangé, R.; Hansen, K. C.; Tao, C.; Cowley, S. W. H.; Stallard, T. S.; Melin, H.; Achilleos, N.; Guio, P.; Badman, S. V.; Kim, T.; Pogorelov, N.

    2017-04-01

    The aurorae of Uranus were recently detected in the far ultraviolet with the Hubble Space Telescope (HST) providing a new, so far unique, means to remotely study the asymmetric Uranian magnetosphere from Earth. We analyze here two new HST Uranus campaigns executed in September 2012 and November 2014 with different temporal coverage and under variable solar wind conditions numerically predicted by three different MHD codes. Overall, the HST images taken with the Space Telescope Imaging Spectrograph reveal auroral emissions in three pairs of successive images (one pair acquired in 2012 and two in 2014), hence 6 additional auroral detections in total, including the most intense Uranian aurorae ever seen with HST. The detected emissions occur close the expected arrival of interplanetary shocks. They appear as extended spots at southern latitudes, rotating with the planet. They radiate 5-24 kR and 1.3-8.8 GW of ultraviolet emission from H2, last for tens of minutes and vary on timescales down to a few seconds. Fitting the 2014 observations with model auroral ovals constrains the longitude of the southern (northern) magnetic pole to 104 ± 26° (284 ± 26°) in the Uranian Longitude System. We suggest that the Uranian near-equinoctial aurorae are pulsed cusp emissions possibly triggered by large-scale magnetospheric compressions.

  6. Intracellular IL-4, IL-5, and IFN-γ as the main characteristic of CD4+CD30+ T cells after allergen stimulation in patients with vernal keratoconjunctivitis

    PubMed Central

    Magaña, Diana; Aguilar, Gustavo; Linares, Marisela; Ayala-Balboa, Julio; Santacruz, Concepción; Chávez, Raúl; Estrada-Parra, Sergio; Garfias, Yonathan; Lascurain, Ricardo; Jiménez-Martínez, Maria C.

    2015-01-01

    Background Vernal keratoconjunctivitis (VKC) is a severe form of allergic conjunctivitis, in which inflammatory infiltrates of the conjunctiva are characterized by CD3+ and CD30+ cells. Until today, the functional involvement of CD30+ T cells in VKC was unclear. Our aim was to evaluate the functional characteristics of CD30+ T cells after allergen stimulation in peripheral blood mononuclear cells obtained from patients with VKC. Methods Seventeen consecutive patients at the Institute of Ophthalmology with active forms of VKC were included. Results After allergen stimulation, we observed the frequency of CD30+ T cells increased compared with non-stimulated cells (p<0.0001). The CD30+ T cells responded to the specific allergen-inducing expression of intracellular interleukin-4 (IL-4), IL-5, and interferon-gamma (IFN-γ) compared with the CD30- T cells (p<0.0001). Increased early secretion of soluble CD30 was observed in the supernatant of the cultured cells from patients with keratoconjunctivitis, compared with healthy controls (p=0.03). Blockage with IL-4 significantly diminished CD30 frequency in the allergen-stimulated cells. Conclusions Our results suggest that after allergenic stimulation, CD4+CD30+ cells are the most important source of IL-4, IL-5, and IFN-γ. IL-4 acts as an activation loop that increases CD30 expression on T cells after specific stimulation. These findings suggest that CD4+CD30+ T cells are effector cells and play a significant role in the immune pathogenic response in patients with vernal keratoconjunctivitis. PMID:25999672

  7. Temporal evolution of the EIA along 95°E as obtained from GNSS TEC measurements and SAMI3 model

    NASA Astrophysics Data System (ADS)

    Kakoti, Geetashree; Kalita, Bitap Raj; Hazarika, Rumajyoti; Bhuyan, Pradip Kumar; Sharma, Sanjay; Tiwari, Ramesh Chandra

    2018-06-01

    The total electron content (TEC) derived from GNSS measurements at a trans-hemispheric meridional chain of ground stations around 95°E longitude are used to study the quiet time inter-hemispheric structure and dynamics of the equatorial ionization anomaly (EIA) during the period March 2015 to February 2016. The stations are Dibrugarh (27.5°N, 95°E, 43° dip), Kohima (25.6°N, 94.1°E, 39° dip), Aizawl (23.7°N, 92.8°E, 36° dip), Port Blair (11.63°N, 92.71°E, 9° dip) and Cocos Islands (12.2°S, 96.8°E, 43° dip). The observation shows that the northern crest of the EIA lies in the south of 23°N (Aizawl) in all seasons but recedes further south towards the equator during December solstice. The largest poleward expansion of the northern (southern) EIA is observed in the March equinox (December solstice). The equinoctial and hemispherical asymmetry of TEC is noted. The winter anomaly is observed in the northern hemisphere but not in the southern hemisphere. The highest midday TEC over any station is observed in the March equinox. The TEC in southern summer (December solstice) is significantly higher than that in the northern summer (June solstice). The observed northern EIA contracts equatorward in the postsunset period of solstice but the southern EIA persists late into the midnight in the December solstice. The asymmetry may be attributed to the different geographic location of the magnetically conjugate stations. The SAMI3 simulations broadly capture the EIA structure and the inter-hemispheric asymmetry during solstices. The difference between observations and the SAMI3 is higher in March equinox and December solstice. The higher E × B vertical drift in the 90-100°E sector and the large geographic-geomagnetic offset in observing stations may have contributed to the observed differences.

  8. Performance of Solar Proxy Options of IRI-Plas Model for Equinox Seasons

    NASA Astrophysics Data System (ADS)

    Sezen, Umut; Gulyaeva, Tamara L.; Arikan, Feza

    2018-02-01

    International Reference Ionosphere (IRI) is the most acclaimed climatic model of the ionosphere. Since 2009, the range of the IRI model has been extended to the Global Positioning System (GPS) orbital height of 20,000 km in the plasmasphere. The new model, which is called IRI extended to Plasmasphere (IRI-Plas), can input not only the ionosonde foF2 and hmF2 but also the GPS-total electron content (TEC). IRI-Plas has been provided at www.ionolab.org, where online computation of ionospheric parameters is accomplished through a user-friendly interface. The solar proxies that are available in IRI-Plas can be listed as sunspot number (SSN1), SSN2, F10.7, global electron content (GEC), TEC, IG, Mg II, Lyman-α, and GEC_RZ. In this study, ionosonde foF2 data are compared with IRI-Plas foF2 values with the Consultative Committee International Radio (CCIR) and International Union of Radio Science (URSI) model choices for each solar proxy, with or without the GPS-TEC input for the equinox months of October 2011 and March 2015. It has been observed that the best fitting model choices in Root Mean Square (RMS) and Normalized RMS (NRMS) sense are the Jet Propulsion Laboratory global ionospheric maps-TEC input with Lyman-α solar proxy option for both months. The input of TEC definitely lowers the difference between the model and ionosonde foF2 values. The IG and Mg II solar proxies produce similar model foF2 values, and they usually are the second and third best fits to the ionosonde foF2 for the midlatitude ionosphere. In high-latitude regions, Jet Propulsion Laboratory global ionospheric map-TEC inputs to IRI-Plas with Lyman-α, GEC_RZ, and TEC solar proxies are the best choices. In equatorial region, the best fitting solar proxies are IG, Lyman-α, and Mg II.

  9. Validation of measured poleward TEC gradient using multi-station GPS with Artificial Neural Network based TEC model in low latitude region for developing predictive capability of ionospheric scintillation

    NASA Astrophysics Data System (ADS)

    Sur, D.; Paul, A.

    2017-12-01

    The equatorial ionosphere shows sharp diurnal and latitudinal Total Electron Content (TEC) variations over a major part of the day. Equatorial ionosphere also exhibits intense post-sunset ionospheric irregularities. Accurate prediction of TEC in these low latitudes is not possible from standard ionospheric models. An Artificial Neural Network (ANN) based Vertical TEC (VTEC) model has been designed using TEC data in low latitude Indian longitude sector for accurate prediction of VTEC. GPS TEC data from the stations Calcutta (22.58°N, 88.38°E geographic, magnetic dip 32°), Baharampore (24.09°N, 88.25°E geographic, magnetic dip 35°) and Siliguri (26.72°N, 88.39°E geographic; magnetic dip 40°) are used as training dataset for the duration of January 2007-September 2011. Poleward VTEC gradients from northern EIA crest to region beyond EIA crest have been calculated from measured VTEC and compared with that obtained from ANN based VTEC model. TEC data from Calcutta and Siliguri are used to compute VTEC gradients during April 2013 and August-September 2013. It has been observed that poleward VTEC gradient computed from ANN based TEC model has shown good correlation with measured values during vernal and autumnal equinoxes of high solar activity periods of 2013. Possible correlation between measured poleward TEC gradients and post-sunset scintillations (S4 ≥ 0.4) from northern crest of EIA has been observed in this paper. From the observation, a suitable threshold poleward VTEC gradient has been proposed for possible occurrence of post-sunset scintillations at northern crest of EIA along 88°E longitude. Poleward VTEC gradients obtained from ANN based VTEC model are used to forecast possible ionospheric scintillation after post-sunset period using the threshold value. It has been observed that these predicted VTEC gradients obtained from ANN based VTEC model can forecast post-sunset L-band scintillation with an accuracy of 67% to 82% in this dynamic low latitude

  10. Corneal staining patterns in vernal keratoconjunctivitis: the new VKC-CLEK scoring scale.

    PubMed

    Leonardi, Andrea; Lazzarini, Daniela; La Gloria Valerio, Alvise; Scalora, Tania; Fregona, Iva

    2018-01-24

    To propose a new scoring system in the assessment of ocular surface epithelial damage in vernal keratoconjunctivitis (VKC). 25 consecutive patients with VKC (50 eyes) were evaluated using the Quality of Life in children with VKC (QUICK) questionnaire and objective clinical measures: fluorescein and lissamine green staining and cornea confocal microscopy (Heidelberg Retina Tomography 3). Oxford, Van Bljsterweld and a new system, the VKC-Collaborative Longitudinal Evaluation of Keratoconus study (CLEK) (VKC-CLEK) scores, were used to evaluate the epithelial damage after staining. Mean Oxford and VKC-CLEK scores were significantly different after fluorescein staining (P<0.001), but significantly correlated (P<0.001; r=0.649). The same data were obtained comparing Van Bljsterweld and VKC-CLEK after lissamine green staining (P<0.001; r=0.760). In patient with limbal VKC, a statistically significant difference was found comparing new VKC-CLEK scores and Oxford or Van Bljsterweld scores (P<0.001), but not in tarsal VKC. A statistically superior concordance was found between QUICK and VKC-CLEK scores compared with standard staining scores values (P<0.001). Oxford and Van Bijsterveld scores are not adequate for the evaluation of the epithelial damage in patients with limbal VKC because the staining patterns considered for these tests do not correspond to the staining patterns in patients with VKC. We propose a new scoring system, VKC-CLEK, to better evaluate both limbal and tarsal epithelial damage in patients with VKC. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  11. Microarray-based IgE detection in tears of patients with vernal keratoconjunctivitis.

    PubMed

    Leonardi, Andrea; Borghesan, Franco; Faggian, Diego; Plebani, Mario

    2015-11-01

    A specific allergen sensitization can be demonstrated in approximately half of the vernal keratoconjunctivitis (VKC) patients by conventional allergic tests. The measurement of specific IgE in tears using a multiplex allergen microarray may offer advantages to identify local sensitization to a specific allergen. In spring-summer 2011, serum and tears samples were collected from 10 active VKC patients (three females, seven males) and 10 age-matched normal subjects. Skin prick test, symptoms score and full ophthalmological examination were performed. Specific serum and tear IgE were assayed using ImmunoCAP ISAC, a microarray containing 103 components derived from 47 allergens. Normal subjects resulted negative for the presence of specific IgE both in serum and in tears. Of the 10 VKC patients, six resulted positive to specific IgE in serum and/or tears. In three of these six patients, specific IgE was found positive only in tears. Cross-reactivity between specific markers was found in three patients. Grass, tree, mites, animal but also food allergen-specific IgE were found in tears. Conjunctival provocation test performed out of season confirmed the specific local conjunctival reactivity. Multiple specific IgE measurements with single protein allergens using a microarray technique in tear samples are a useful, simple and non-invasive diagnostic tool. ImmunoCAP ISAC detects allergen sensitization at component level and adds important information by defining both cross- and co-sensitization to a large variety of allergen molecules. The presence of specific IgE only in tears of VKC patients reinforces the concept of possible local sensitization. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  12. Solar activity variations of equatorial spread F occurrence and sustenance during different seasons over Indian longitudes: Empirical model and causative mechanisms

    NASA Astrophysics Data System (ADS)

    Madhav Haridas, M. K.; Manju, G.; Arunamani, T.

    2018-05-01

    A comprehensive analysis using nearly two decades of ionosonde data is carried out on the seasonal and solar cycle variations of Equatorial Spread F (ESF) irregularities over magnetic equatorial location Trivandrum (8.5°N, 77°E). The corresponding Rayleigh Taylor (RT) instability growth rates (γ) are also estimated. A seasonal pattern of ESF occurrence and the corresponding γ is established for low solar (LSA), medium solar (MSA) and high solar (HSA) activity periods. For LSA, it is seen that the γ maximizes during post sunset time with comparable magnitudes for autumnal equinox (AE), vernal equinox (VE) and winter solstice (WS), while for summer solstice (SS) it maximizes in the post-midnight period. Concurrent responses are seen in the ESF occurrence pattern. For MSA, γ maximizes during post-sunset for VE followed by WS and AE while SS maximises during post-midnight period. The ESF occurrence for MSA is highest for VE (80%), followed by AE (70%), WS (60%) and SS (50%). In case of HSA, maximum γ occurs for VE followed by AE, WS and SS. The concurrent ESF occurrence maximizes for VE and AE (90%), WS and SS at 70%. The solar cycle variation of γ is examined. γ shows a linear variation with F10.7 cm flux. Further, ESF percentage occurrence and duration show an exponential and linear variation respectively with γ. An empirical model on the solar activity dependence of ESF occurrence and sustenance time over Indian longitudes is arrived at using the database spanning two solar cycles for the first time.

  13. ISKANDARnet IOMOS: Near real-time equatorial space weather monitoring and alert system in Peninsular Malaysia

    NASA Astrophysics Data System (ADS)

    Musa, Tajul Ariffin; Leong, Shien Kwun; Abdullah, Khairul Anuar; Othman, Rusli

    2012-11-01

    This work proposes ISKANDARnet Ionospheric Outburst MOnitoring and alert System (IOMOS), along with Ionospheric Outburst Index (IOX) to develop an operational near real-time space weather service for Malaysia. The IOMOS is based on Global Positioning System (GPS) Network-based Real-Time Kinematic (NRTK) concept which is by nature for atmospheric (ionosphere and troposphere) modeling within the network coverage. The elegance of this solution lies in the fact that IOMOS utilize differential ionospheric residual from network of GPS baselines which incur no additional cost for operation. Users will be informed about the ionospheric perturbation through Short Message Service (SMS), email or Twitter®. This approach will ultimately beneficial for the navigation and satellite positioning communities, particularly during the coming Solar Cycle 24. In addition, a combination of local and global GPS network has been employed to study the equatorial ionosphere geomorphology and climatology in the Malaysian sector. Equatorial Total Electron Content (TEC) over Malaysia shows semi-annual, annual, and seasonal variations with maximum values appearing during equinoctial months and minimum during solstices months. The TEC value during vernal equinox is about 21% higher than autumnal equinox, and December solstice exceeds that at the June solstice by around 14%. It is also found that semi-annual variation is present at all levels of solar activity, whereas June solstice predominates December solstice during high solar activity for annual and seasonal variations. In near future, a near real-time TEC derivation system will be developed to support equatorial ionosphere modeling to enhance space weather service for Malaysia.

  14. 76 FR 7528 - Endangered and Threatened Wildlife and Plants; 90-Day Finding on a Petition To Revise Critical...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-10

    ... Revise Critical Habitat for Vernal Pool Fairy Shrimp and Vernal Pool Tadpole Shrimp AGENCY: Fish and... critical habitat for vernal pool fairy shrimp (Branchinecta lynchi) and vernal pool tadpole shrimp... revision of the critical habitat for vernal pool fairy shrimp and vernal pool tadpole shrimp may be...

  15. L-band nighttime scintillations at the northern edge of the EIA along 95°E during the ascending half of the solar cycle 24

    NASA Astrophysics Data System (ADS)

    Dutta, Barsha; Kalita, Bitap Raj; Bhuyan, Pradip Kumar

    2018-04-01

    The characteristics of nighttime ionospheric scintillations measured at the L-band frequency of 1.575 GHz over Dibrugarh (27.5°N, 95°E, MLAT ∼ 17°N, 43° dip) during the ascending half of the solar cycle 24 from 2010 to 2014 have been investigated and the results are presented in this paper. The measurement location is within or outside the zone of influence of the equatorial ionization anomaly depending on solar and geomagnetic activity. Maximum scintillation is observed in the equinoxes irrespective of solar activity with clear asymmetry between March and September. The occurrence frequency in the solstices shifts from minimum in the June solstice in low solar activity to a minimum in the December solstice in high solar activity years. A significant positive correlation of occurrence of scintillations in the June solstice with solar activity has been observed. However, earlier reports from the Indian zone (∼75°E) indicate negative or no correlation of scintillation in June solstice with solar activity. Scintillations activity/occurrence in solstices indicates a clear positive correlation with Es recorded simultaneously by a collocated Ionosonde. In equinoxes, maximum scintillations occur in the pre-midnight hours while in solstices the occurrence frequency peaks just after sunset. The incidence of strong scintillations (S4 ≥ 0.4) increases with increase in solar activity. Strong (S4 ≥ 0.4) ionospheric scintillations accompanied by TEC depletions in the pre-midnight period is attributed to equatorial irregularities whereas the dusk period scintillations are related to the sporadic-E activity. Present results thus indicate that the current location at the northern edge of the EIA behaves as low as well as mid-latitude location.

  16. A thermosphere-ionosphere-mesosphere-electrodynamic general circulation model (time-GCM): Equinox solar cycle minimum simulations (30-500 km)

    NASA Technical Reports Server (NTRS)

    Roble, R. G.; Ridley, E. C.

    1994-01-01

    A new simulation model of the mesosphere, thermosphere, and ionosphere with coupled electrodynamics has been developed and used to calculate the global circulation, temperature and compositional structure between 30-500 km for equinox, solar cycle minimum, geomagnetic quiet conditions. The model incorporates all of the features of the National Center for Atmospheric Research (NCAR) thermosphere-ionosphere- electrodynamics general circulation model (TIE-GCM) but the lower boundary has been extended downward from 97 to 30 km (10 mb) and it includes the physical and chemical processes appropriate for the mesosphere and upper stratosphere. The first simulation used Rayleigh friction to represent gravity wave drag in the middle atmosphere and although it was able to close the mesospheric jets it severely damped the diurnal tide. Reduced Rayleigh friction allowed the tide to penetrate to thermospheric heights but did not close the jets. A gravity wave parameterization developed by Fritts and Lu (1993) allows both features to exist simultaneously with the structure of tides and mean flow dependent upon the strength of the gravity wave source. The model calculates a changing dynamic structure with the mean flow and diurnal tide dominant in the mesosphere, the in-situ generated semi-diurnal tide dominating the lower thermosphere and an in-situ generated diurnal tide in the upper thermosphere. The results also show considerable interaction between dynamics and composition, especially atomic oxygen between 85 and 120 km.

  17. Calendar motifs on Getashen hydria

    NASA Astrophysics Data System (ADS)

    Vrtanesyan, Garegin

    2015-07-01

    Getashen hydria was found in the tombs of the middle bronze age (the first third of the second Millennium B.C.) in Armenia (Lake Sevan). It shows a scene consisting of three friezes. On the lower frieze depicts six zoomorphic figures, on an average six frieze waterfowl, and on top, is the graphic signs. Calendar motives of this composition have a numeric expression, six zoomorphic figures on the lower and middle friezes. Division of the annual cycle into two parts is known in the calendars of the ancient Indo-Iranian ("great summer" and "the great winter"). Animals on the lower frieze of the second mark, "winter" road of the Sun, because in this period are the most important events, ensuring the reproduction of the economy of the society. This rut ungulates - wild (deer) and domestic (goats). Moreover, the gon goats end in December, almost coinciding with the onset of the winter solstice. A couple of dogs on the lower frieze marks the version of the myth, imprisoned in the rock hero - the Sun (Mihr - Artavazd), to which his dogs have to chew the chains, anticipating his exit at the winter solstice. This is indicated by the direction of their movement, the Sun moves from left to right for an observer, only when located on the South side of the sky (i.e., beginning with the autumnal equinox). The most important event of the period of "summer road" of the Sun is the vernal equinox, which coincide with the arrival of waterfowl (ducks, geese). Their direction on the second frieze (left to right) corresponds to the position of the observer, facing North.

  18. Variation of GPS-TEC in a low latitude Indian region during the year 2012 and 2013

    NASA Astrophysics Data System (ADS)

    Patel, Nilesh C.; Karia, Sheetal P.; Pathak, Kamlesh N.

    2018-05-01

    The paper is based on the ionospheric variations in terms of vertical total electron content (VTEC) for the period from January 2012 to December 2013 based on the analysis of dual frequency signals from the Global Positioning System (GPS) satellites recorded at ground stations Surat (21.16°N, 72.78°E Geog.), situated under the northern crest of the equatorial ionization anomaly region (EIA) and other three International GNSS Service (IGS) stations Bangalore (13.02°N, 77.57°E Geog.), Hyderabad (17.25°N, 78.30°E Geog.), and Lucknow (26.91°N, 80.95°E Geog.) in India. We describe the diurnal and seasonal characteristics. It was observed that GPS-TEC reaches its maximum value between 12:00 and 16:00 IST. Further, Seasonal variations of GPS-TEC is categorized into four seasons, i.e., March equinox (February, March, and April), June solstice (May, June, and July), September equinox (August, September, and October) and December solstice (November, December and January). The forenoon rate of production in Lucknow (beyond EIA crest) is faster than Bangalore, Hyderabad and Surat station. It is found that September equinox shows GPS-TEC slightly higher than the March equinox, followed by June solstice and the lowest GPS-TEC are in winter solstice at four stations. The equinoctial asymmetry clearly observed in the current study. Also GPS-TEC shows a semiannual variation.

  19. Seasonal variations of temperature, acetylene and ethane in Saturn's atmosphere from 2005 to 2010, as observed by Cassini-CIRS

    NASA Astrophysics Data System (ADS)

    Sinclair, J. A.; Irwin, P. G. J.; Fletcher, L. N.; Moses, J. I.; Greathouse, T. K.; Friedson, A. J.; Hesman, B.; Hurley, J.; Merlet, C.

    2013-07-01

    Acetylene (C2H2) and ethane (C2H6) are by-products of complex photochemistry in the stratosphere of Saturn. Both hydrocarbons are important to the thermal balance of Saturn's stratosphere and serve as tracers of vertical motion in the lower stratosphere. Earlier studies of Saturn's hydrocarbons using Cassini-CIRS observations have provided only a snapshot of their behaviour. Following the vernal equinox in August 2009, Saturn's northern and southern hemispheres have entered spring and autumn, respectively, however the response of Saturn's hydrocarbons to this seasonal shift remains to be determined. In this paper, we investigate how the thermal structure and concentrations of acetylene and ethane have evolved with the changing season on Saturn. We retrieve the vertical temperature profiles and acetylene and ethane volume mixing ratios from Δν˜=15.5cm-1 Cassini-CIRS observations. In comparing 2005 (solar longitude, Ls ˜ 308°), 2009 (Ls ˜ 3°) and 2010 (Ls ˜ 15°) results, we observe the disappearance of Saturn's warm southern polar hood with cooling of up to 17.1 K ± 0.8 K at 1.1 mbar at high-southern latitudes. Comparison of the derived temperature trend in this region with a radiative climate model (Section 4 of Fletcher et al., 2010 and Greathouse et al. (2013, in preparation)) indicates that this cooling is radiative although dynamical changes in this region cannot be ruled out. We observe a 21 ± 12% enrichment of acetylene and a 29 ± 11% enrichment of ethane at 25°N from 2005 to 2009, suggesting downwelling at this latitude. At 15°S, both acetylene and ethane exhibit a decrease in concentration of 6 ± 11% and 17 ± 9% from 2005 to 2010, respectively, which suggests upwelling at this latitude (though a statistically significant change is only exhibited by ethane). These implied vertical motions at 15°S and 25°N are consistent with a recently-developed global circulation model of Saturn's tropopause and stratosphere(Friedson and Moses, 2012), which

  20. Statistical behavior of the longitudinal variations of daytime electron density in the topside ionosphere at middle latitudes

    NASA Astrophysics Data System (ADS)

    Su, Fanfan; Wang, Wenbin; Burns, Alan G.; Yue, Xinan; Zhu, Fuying; Lin, Jian

    2016-11-01

    Electron density in the topside ionosphere has significant variations with latitude, longitude, altitude, local time, season, and solar cycle. This paper focuses on the global and seasonal features of longitudinal structures of daytime topside electron density (Ne) at middle latitudes and their possible causes. We used in situ Ne measured by DEMETER and F2 layer peak height (hmF2) and peak density (NmF2) from COSMIC. The longitudinal variations of the daytime topside Ne show a wave number 2-type structure in the Northern Hemisphere, whereas those in the Southern Hemisphere are dominated by a wave number 1 structure and are much larger than those in the Northern Hemisphere. The patterns around December solstice (DS) in the Northern Hemisphere (winter) are different from other seasons, whereas the patterns in the Southern Hemisphere are similar in each season. Around March equinox (ME), June solstice (JS), and September equinox (SE) in the Northern Hemisphere and around ME, SE, and DS in the Southern Hemisphere, the longitudinal variations of topside Ne have similar patterns to hmF2. Around JS in the Southern Hemisphere (winter), the topside Ne has similar patterns to NmF2 and hmF2 does not change much with longitude. Thus, the topside variations may be explained intuitively in terms of hmF2 and NmF2. This approach works reasonably well in most of the situations except in the northern winter in the topside not too far from the F2 peak. In this sense, understanding variations in hmF2 and NmF2 becomes an important and relevant subject for this topside ionospheric study.

  1. Direct Simulation Monte Carlo modelling of the major species in the coma of comet 67P/Churyumov-Gerasimenko

    NASA Astrophysics Data System (ADS)

    Fougere, Nicolas; Altwegg, K.; Berthelier, J.-J.; Bieler, A.; Bockelée-Morvan, D.; Calmonte, U.; Capaccioni, F.; Combi, M. R.; De Keyser, J.; Debout, V.; Erard, S.; Fiethe, B.; Filacchione, G.; Fink, U.; Fuselier, S. A.; Gombosi, T. I.; Hansen, K. C.; Hässig, M.; Huang, Z.; Le Roy, L.; Leyrat, C.; Migliorini, A.; Piccioni, G.; Rinaldi, G.; Rubin, M.; Shou, Y.; Tenishev, V.; Toth, G.; Tzou, C.-Y.

    2016-11-01

    We analyse the Rosetta Orbiter Spectrometer for Ion and Neutral Analysis (ROSINA) - the Double Focusing Mass Spectrometer data between 2014 August and 2016 February to examine the effect of seasonal variations on the four major species within the coma of 67P/Churyumov-Gerasimenko (H2O, CO2, CO, and O2), resulting from the tilt in the orientation of the comet's spin axis. Using a numerical data inversion, we derive the non-uniform activity distribution at the surface of the nucleus for these species, suggesting that the activity distribution at the surface of the nucleus has not significantly been changed and that the differences observed in the coma are solely due to the variations in illumination conditions. A three-dimensional Direct Simulation Monte Carlo model is applied where the boundary conditions are computed with a coupling of the surface activity distributions and the local illumination. The model is able to reproduce the evolution of the densities observed by ROSINA including the changes happening at equinox. While O2 stays correlated with H2O as it was before equinox, CO2 and CO, which had a poor correlation with respect to H2O pre-equinox, also became well correlated with H2O post-equinox. The integration of the densities from the model along the line of sight results in column densities directly comparable to the VIRTIS-H observations. Also, the evolution of the volatiles' production rates is derived from the coma model showing a steepening in the production rate curves after equinox. The model/data comparison suggests that the seasonal effects result in the Northern hemisphere of 67P's nucleus being more processed with a layered structure while the Southern hemisphere constantly exposes new material.

  2. A High-Altitude Search for Vulcanoids: Progress Report

    NASA Astrophysics Data System (ADS)

    Durda, D. D.; Stern, S. A.; Terrell, D. C.; Weidenschilling, S. J.

    2002-09-01

    We are conducting a unique, high-altitude observing campaign to search for vulcanoids, a population of small, asteroid-like bodies hypothesized to reside in the dynamically stable region interior to Mercury's orbit (i.e., orbits with aphelia <0.21 AU). This airborne search campaign utilizes our versatile and highly capable SWUIS-A (Southwest Universal Imaging System - Airborne) instrument flown with the flight astronomer (SAS and DDD) to an altitude of 49,000 MSL aboard NASA F/A-18B aircraft in order to obtain darker twilight conditions for near-Sun observing than are possible from the ground. The first observing run was successfully completed at NASA's Dryden Flight Research Center during the March/April 2002 vernal equinox observing opportunity. On each of the three evening flights we recorded image data covering 250 square degrees of sky centered on the ecliptic from solar elongations of 6-18 deg. Initial reduction of portions of the Mar/Apr 2002 data set demonstrates that we are reliably detecting objects to magnitude V = 9.5 at 15 degrees solar elongation. This is at least a magnitude fainter than the best previous ground-based searches and comparable to the faintest stars visible in our space-based SOHO LASCO C3 coronagraph vulcanoids search. The SWUIS-A instrument itself is capable of imaging objects as faint as magnitude V = 13, corresponding to vulcanoids less than 10 km across, with a sufficiently dark sky background; we are working to mitigate sky background brightness to reach these deeper magnitude limits for a second F/A-18B observing run during the September 2002 autumnal equinox observing opportunity. We thank NASA research pilots Rick Searfoss, Dana Purifoy, and Craig Bomben. This research is supported by the NASA Planetary Astronomy program, NASA's Dryden Flight Research Center, and the National Geographic Society.

  3. Numerical simulation of the 6 day wave effects on the ionosphere: Dynamo modulation

    NASA Astrophysics Data System (ADS)

    Gan, Quan; Wang, Wenbing; Yue, Jia; Liu, Hanli; Chang, Loren C.; Zhang, Shaodong; Burns, Alan; Du, Jian

    2016-10-01

    The Thermosphere-Ionosphere-Mesosphere Electrodynamics General Circulation Model (TIME-GCM) is used to theoretically study the 6 day wave effects on the ionosphere. By introducing a 6 day perturbation with zonal wave number 1 at the model lower boundary, the TIME-GCM reasonably reproduces the 6 day wave in temperature and horizontal winds in the mesosphere and lower thermosphere region during the vernal equinox. The E region wind dynamo exhibits a prominent 6 day oscillation that is directly modulated by the 6 day wave. Meanwhile, significant local time variability (diurnal and semidiurnal) is also seen in wind dynamo as a result of altered tides due to the nonlinear interaction between the 6 day wave and migrating tides. More importantly, the perturbations in the E region neutral winds (both the 6 day oscillation and tidal-induced short-term variability) modulate the polarization electric fields, thus leading to the perturbations in vertical ion drifts and ionospheric F2 region peak electron density (NmF2). Our modeling work shows that the 6 day wave couples with the ionosphere via both the direct neutral wind modulation and the interaction with atmospheric tides.

  4. Vortices in Saturn’s Northern Hemisphere (2008–2015) Observed by Cassini ISS

    PubMed Central

    Trammell, Harold Justin; Li, Liming; Jiang, Xun; Pan, Yefeng; Smith, Mark A.; Bering, Edgar A.; Hörst, Sarah M.; Vasavada, Ashwin R.; Ingersoll, Andrew P.; Janssen, Michael A.; West, Robert A.; Porco, Carolyn C.; Li, Cheng; Simon, Amy A.; Baines, Kevin H.

    2018-01-01

    We use observations from the Imaging Science Subsystem on Cassini to create maps of Saturn’s Northern Hemisphere (NH) from 2008 to 2015, a time period including a seasonal transition (i.e., Spring Equinox in 2009) and the 2010 giant storm. The processed maps are used to investigate vortices in the NH during the period of 2008–2015. All recorded vortices have diameters (east-west) smaller than 6000 km except for the largest vortex that developed from the 2010 giant storm. The largest vortex decreased its diameter from ~11000 km in 2011 to ~5000 km in 2015, and its average diameter is ~6500 km during the period of 2011–2015. The largest vortex lasts at least 4 years, which is much longer than the lifetimes of most vortices (less than 1 year). The largest vortex drifts to north, which can be explained by the beta drift effect. The number of vortices displays varying behaviors in the meridional direction, in which the 2010 giant storm significantly affects the generation and development of vortices in the middle latitudes (25–45°N). In the higher latitudes (45–90°N), the number of vortices also displays strong temporal variations. The solar flux and the internal heat do not directly contribute to the vortex activities, leaving the temporal variations of vortices in the higher latitudes (45–90°N) unexplained. PMID:29629249

  5. On the Relation Between Soft Electron Precipitations in the Cusp Region and Solar Wind Coupling Functions

    NASA Astrophysics Data System (ADS)

    Dang, Tong; Zhang, Binzheng; Wiltberge, Michael; Wang, Wenbin; Varney, Roger; Dou, Xiankang; Wan, Weixing; Lei, Jiuhou

    2018-01-01

    In this study, the correlations between the fluxes of precipitating soft electrons in the cusp region and solar wind coupling functions are investigated utilizing the Lyon-Fedder-Mobarry global magnetosphere model simulations. We conduct two simulation runs during periods from 20 March 2008 to 16 April 2008 and from 15 to 24 December 2014, which are referred as "Equinox Case" and "Solstice Case," respectively. The simulation results of Equinox Case show that the plasma number density in the high-latitude cusp region scales well with the solar wind number density (ncusp/nsw=0.78), which agrees well with the statistical results from the Polar spacecraft measurements. For the Solstice Case, the plasma number density of high-latitude cusp in both hemispheres increases approximately linearly with upstream solar wind number density with prominent hemispheric asymmetry. Due to the dipole tilt effect, the average number density ratio ncusp/nsw in the Southern (summer) Hemisphere is nearly 3 times that in the Northern (winter) Hemisphere. In addition to the solar wind number density, 20 solar wind coupling functions are tested for the linear correlation with the fluxes of precipitating cusp soft electrons. The statistical results indicate that the solar wind dynamic pressure p exhibits the highest linear correlation with the cusp electron fluxes for both equinox and solstice conditions, with correlation coefficients greater than 0.75. The linear regression relations for equinox and solstice cases may provide an empirical calculation for the fluxes of cusp soft electron precipitation based on the upstream solar wind driving conditions.

  6. Methylation controls the low temperature induction of flowering in Arabidopsis.

    PubMed

    Dennis, E S; Bilodeau, P; Burn, J; Finnegan, E J; Genger, R; Helliwell, C; Kang, B J; Sheldon, C C; Peacock, W J

    1998-01-01

    Control of the transition to flowering is critical for reproductive success of a plant. Studies in Arabidopsis have led us to suggest how this species has harnessed the environmental cue of a period of low temperature to ensure flowering occurs at an appropriate time. We propose that Arabidopsis has both vernalization-independent and vernalization-dependent pathways for the initiation of inflorescence development in the shoot apex. The vernalization-independent pathway may be concerned with the supply of carbohydrate to the shoot apex. In late flowering ecotypes which respond to vernalization the vernalization-independent pathway is blocked by the action of two dominant repressors of flowering, FRI and FLC, which interact to produce very late flowering plants which respond strongly to vernalization. We have isolated a gene which may correspond to FLC. We suggest the vernalization-dependent pathway, which may be concerned with apical GA biosynthesis, is blocked by methylation of a gene critical for flowering. This gene may correspond to that encoding kaurenoic acid hydroxylase (KAH), an enzyme catalysing a step in the GA biosynthetic pathway. Under this scheme vernalization causes unblocking of this pathway by demethylation possibly of the KAH gene and consequent biosynthesis of active GAs in the apex.

  7. Northern Studies at Northern Universities.

    ERIC Educational Resources Information Center

    Northern Review: A Multidisciplinary Journal of the Arts and Social Sciences of the North, 1994

    1994-01-01

    Describes college programs and research projects focused on the Arctic, northern studies, or northern concerns at Athabasca University (Alberta), the University of British Columbia, the University of Alaska Anchorage, the University of Alaska Fairbanks, the Scott Polar Institute at the University of Cambridge (England), and Kent State University…

  8. Titan's cloud seasonal activity from winter to spring with Cassini/VIMS

    USGS Publications Warehouse

    Rodriguez, S.; Le, Mouelic S.; Rannou, P.; Sotin, Christophe; Brown, R.H.; Barnes, J.W.; Griffith, C.A.; Burgalat, J.; Baines, K.H.; Buratti, B.J.; Clark, R.N.; Nicholson, P.D.

    2011-01-01

    Since Saturn orbital insertion in July 2004, the Cassini orbiter has been observing Titan throughout most of the northern winter season (October 2002-August 2009) and the beginning of spring, allowing a detailed monitoring of Titan's cloud coverage at high spatial resolution with close flybys on a monthly basis. This study reports on the analysis of all the near-infrared images of Titan's clouds acquired by the Visual and Infrared Mapping Spectrometer (VIMS) during 67 targeted flybys of Titan between July 2004 and April 2010.The VIMS observations show numerous sporadic clouds at southern high and mid-latitudes, rare clouds in the equatorial region, and reveal a long-lived cloud cap above the north pole, ubiquitous poleward of 60??N. These observations allow us to follow the evolution of the cloud coverage during almost a 6-year period including the equinox, and greatly help to further constrain global circulation models (GCMs). After 4. years of regular outbursts observed by Cassini between 2004 and 2008, southern polar cloud activity started declining, and completely ceased 1. year before spring equinox. The extensive cloud system over the north pole, stable between 2004 and 2008, progressively fractionated and vanished as Titan entered into northern spring. At southern mid-latitudes, clouds were continuously observed throughout the VIMS observing period, even after equinox, in a latitude band between 30??S and 60??S. During the whole period of observation, only a dozen clouds were observed closer to the equator, though they were slightly more frequent as equinox approached. We also investigated the distribution of clouds with longitude. We found that southern polar clouds, before disappearing in mid-2008, were systematically concentrated in the leading hemisphere of Titan, in particular above and to the east of Ontario Lacus, the largest reservoir of hydrocarbons in the area. Clouds are also non-homogeneously distributed with longitude at southern mid

  9. Evaluation of retinal nerve fiber layer thickness in vernal keratoconjunctivitis patients under long-term topical corticosteroid therapy.

    PubMed

    Cingu, Abdullah Kursat; Cinar, Yasin; Turkcu, Fatih Mehmet; Sahinoglu-Keskek, Nedime; Sahin, Alparslan; Sahin, Muhammed; Yuksel, Harun; Caca, Ihsan

    2014-09-01

    The aim of this study was to evaluate the retinal nerve fiber layer (RNFL) thickness in vernal keratoconjunctivitis (VKC) patients who were under long-term topical corticosteroid therapy. Thirty-six eyes of 36 VKC patients with clear cornea and normal videokeratography and 40 eyes of 40 age- and gender-matched normal children were included in the study. Clinical and demographic characteristics of the patients were noted and detailed ophthalmological examination was performed. Visual acuity (VA), spherical equivalent (SE), axial length (AL) and RNFL thickness measurements were compared between the groups. To correct ocular magnification effect on RNFL, we used Littmann's formula. All VKC patients had history of topical corticosteroid use and the mean duration of the topical corticosteroid use was 23.8 ± 9.09 months. There was no significant difference between the groups in terms of intraocular pressure (IOP). VKC group had significantly worse VA, greater SE and AL and thinner mean global, superior and inferior RNFL thickness. There were significant negative correlations between the duration of topical corticosteroid use and the mean global, superior and temporal RNFL thickness in VKC group. After correction of magnification effect, VKC group still had thinner mean global, superior and inferior RNFL thickness, and significant difference between the groups in inferior RNFL thickness did not disappear. Significant RNFL thickness difference between the groups suggests a possible effect of long-term corticosteroid use in VKC patients. Because visual field (VF) analysis in pediatric patients is difficult to perform and IOP may be illusive, RNFL thickness measurements in addition to routine examinations in VKC patients may help clinicians in their practice.

  10. A single haplotype hyposensitive to light and requiring strong vernalization dominates Arabidopsis thaliana populations in Patagonia, Argentina.

    PubMed

    Kasulin, Luciana; Rowan, Beth A; León, Rolando J C; Schuenemann, Verena J; Weigel, Detlef; Botto, Javier F

    2017-07-01

    The growing collection of sequenced or genotyped Arabidopsis thaliana accessions includes mostly individuals from the native Eurasian and N. African range and introduced North American populations. Here, we describe the genetic and phenotypic diversity, along with habitats and life history, of A. thaliana plants collected at the southernmost end of its worldwide distribution. Seed samples were harvested from plants growing in four sites within a ~3500-km 2 -area in Patagonia, Argentina, and represent the first germplasm to be collected in South America for this species. Whole-genome resequencing revealed that plants from the four sites and a Patagonia herbarium specimen collected in 1967 formed a single haplogroup (Pat), indicating that the phenotypic variation observed in the field reflected plastic responses to the environment. admixture and principal components analyses suggest that the ancestor of the Pat haplogroup either came from Italy or the Balkan/Caucasus regions of Eurasia. In the laboratory, plants from the Pat haplogroup were hyposensitive to continuous red (Rc) and shade light, with corresponding changes in the expression of phytochrome signalling genes. Pat had higher PIF3 and PIF5 and lower HY5 expression under Rc light; and lower expression of PIL1, ATHB2 and HFR1 under shade compared to Col-0. In addition, Pat plants had a strong vernalization requirement associated with high levels of FLC expression. We conclude that including Pat in studies of natural variation and in comparison with other introduced populations will provide additional information for association studies and allow for a more detailed assessment of the demographic events following colonization. © 2017 John Wiley & Sons Ltd.

  11. Increased prevalence of growth hormone deficiency in patients with vernal keratoconjuntivitis; an interesting new association.

    PubMed

    Stagi, Stefano; Pucci, Neri; di Grande, Laura; de Libero, Cinzia; Caputo, Roberto; Pantano, Stefano; Seminara, Salvatore; de Martino, Maurizio; Novembre, Elio

    2014-01-01

    Vernal keratoconjunctivitis (VKC) is a chronic conjunctivitis that mainly affects children living in temperate areas. The notable difference between genders and VKC's resolution with puberty have persistently suggested a role of hormonal factors in VKC development. To describe six cases of males with VKC and growth hormone deficiency (GHD) reported as a long-term follow-up during rhGH treatment. Six consecutive male patients (median age at GHD diagnosis 9.7, range 7.9 to 13.1 years) with VKC, were recruited from July 2005 to July 2013 at the Paediatric Endocrinology Unit of Anna Meyer Children's Hospital in Florence, Italy. In these patients, anthropometric data were collected periodically. In three of these patients, data were collected to near-adult or adult height. Familial history was uneventful for all patients. The target height was normal, ranging from 0.65 standard deviation scores (SDS) to 2.01 SDS. The patients showed a normal birth-weight (from -1.21 to 1.35 SDS) and birth-length (from -0.93 to 1.21 SDS). At GHD diagnosis, all of the patients exhibited demonstrated important growth retardation (from -2.05 to -2.78 SDS). Plasmatic concentrations of IGF-1 and IGFBP-3 were low (from -1.85 to -3 SDS and from -1.81 to -2.76 SDS, respectively). GH stimulation tests showed classic GHD symptoms in all of the patients. Pubertal onset was normal. All of the patients treated with rhGH responded well to rhGH treatment. Adult height, evaluated in three patients, was in accordance with their target height. To our current knowledge, we have described for the first time six patients affected by VKC with GH deficiency, in some of whom we performed a long-term follow-up to adult height. Further studies will be needed to establish whether GHD may be a common feature of VKC patients. Nevertheless, it appears to be useful to carefully follow statural growth of VKC patients, while the possibility of a GH deficiency must to be taken into account in the presence of growth

  12. Lack of adaptation from standing genetic variation despite the presence of putatively adaptive alleles in introduced sweet vernal grass (Anthoxanthum odoratum).

    PubMed

    Gould, B; Geber, M

    2016-01-01

    Population genetic theory predicts that the availability of appropriate standing genetic variation should facilitate rapid evolution when species are introduced to new environments. However, few tests of rapid evolution have been paired with empirical surveys for the presence of previously identified adaptive genetic variants in natural populations. In this study, we examined local adaptation to soil Al toxicity in the introduced range of sweet vernal grass (Anthoxanthum odoratum), and we genotyped populations for the presence of Al tolerance alleles previously identified at the long-term ecological Park Grass Experiment (PGE, Harpenden, UK) in the species native range. We found that markers associated with Al tolerance at the PGE were present at appreciable frequency in introduced populations. Despite this, there was no strong evidence of local adaptation to soil Al toxicity among populations. Populations demonstrated significantly different intrinsic root growth rates in the absence of Al. This suggests that selection on correlated root growth traits may constrain the ability of populations to evolve significantly different root growth responses to Al. Our results demonstrate that genotype-phenotype associations may differ substantially between the native and introduced parts of a species range and that adaptive alleles from a native species range may not necessarily promote phenotypic differentiation in the introduced range. © 2015 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2015 European Society For Evolutionary Biology.

  13. 77 FR 43350 - Draft Environmental Assessment and Proposed Habitat Conservation Plan for the San Diego Unified...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-24

    ...) restoration and enhancement of vernal pools occupied by San Diego fairy shrimp on the McAuliffe Park and... would permanently remove all San Diego fairy shrimp and its vernal pool habitat from the project site. To mitigate impacts to the San Diego fairy shrimp and its vernal pool habitat, the applicant would...

  14. Mars Global Surveyor Radio Science Electron Density Profiles: Interannual Variability and Implications for the Neutral Atmosphere

    NASA Technical Reports Server (NTRS)

    Bougher, S. W.; Engel, S.; Hinson, D. P.; Murphy, J. R.

    2003-01-01

    The Mars Global Surveyor (MGS) Radio Science (RS) experiment employs an ultrastable oscillator aboard the spacecraft. The signal from the oscillator to Earth is refracted by the Martian ionosphere, allowing retrieval of electron density profiles versus radius and geopotential. The present analysis is carried out on five sets of occultation measurements: (1) four obtained near northern summer solstice (Ls = 74-116, near aphelion) at high northern latitudes (64.7-77.6N), and (2) one set of profiles approaching equinox conditions (Ls = 135- 146) at high southern latitudes (64.7-69.1S). Electron density profiles (95 to 200 km) are examined over a narrow range of solar zenith angles (76.5-86.9 degrees) for local true solar times of (1) 3-4 hours and (2) 12.1 hours. Variations spanning 1-Martian year are specifically examined in the Northern hemisphere.

  15. Differences of the Plasma Drift and Upper Thermospheric Wind Behaviour in the Northern and Southern Polar Regions due to the Geomagnetic Field Asymmetry

    NASA Astrophysics Data System (ADS)

    Foerster, M.; Cnossen, I.; Haaland, S.

    2013-12-01

    The non-dipolar portions of Earth's main magnetic field constitute substantial differences between the geomagnetic field configurations of both hemispheres. They cause in particular different magnetic field flux densities in the opposite polar regions and different offsets of the invariant poles with respect to the rotation axis of the Earth. The offset is presently considerable larger (factor ~2) in the Southern Hemisphere compared to the Northern, which has substantial implications for the coupled magnetosphere-ionosphere-thermosphere system under the influence of external drivers. Recent observations have shown that the ionospheric/thermospheric response to solar wind and IMF dependent processes in the magnetosphere can be very dissimilar in the Northern and Southern Hemisphere. We present statistical studies of both the high-latitude ionospheric convection and the upper thermospheric circulation patterns obtained from almost a decade of measurements starting in 2001 of the electron drift instrument (EDI) on board the Cluster satellites and an accelerometer on board the CHAMP spacecraft, respectively. Using the Coupled Magnetosphere-Ionosphere-Thermosphere (CMIT) model, on the other hand, we simulated a 20-day spring equinox interval of low solar activity with both symmetric dipole and realistic (IGRF) geomagnetic field configurations to prove the importance of the hemispheric differences for the plasma and neutral wind dynamics. The survey of both the numerical simulation and the statistical observation results show some prominent asymmetries between the two hemispheres, which are likely due to the different geographic-geomagnetic offset, or even due to different patterns of geomagnetic flux densities. Plasma drift differences can partly be attributed to differing ionospheric conductivities. The forthcoming Swarm satellite mission will provide valuable observations for further detailed analyses of the North-South asymmetries of plasma convection and neutral

  16. Mapping polar atmospheric features on Titan with VIMS: From the dissipation of the northern cloud to the onset of a southern polar vortex

    NASA Astrophysics Data System (ADS)

    Le Mouélic, S.; Rodriguez, S.; Robidel, R.; Rousseau, B.; Seignovert, B.; Sotin, C.; Barnes, J. W.; Brown, R. H.; Baines, K. H.; Buratti, B. J.; Clark, R. N.; Nicholson, P. D.; Rannou, P.; Cornet, T.

    2018-09-01

    We have analyzed the complete archive of the Visual and Infrared Mapping Spectrometer (VIMS) data in order to monitor and analyze the evolution of the clouds and haze coverage at both poles of Titan during the entire Cassini mission. Our objective is to give a cartographic synopsis from a VIMS perspective, to provide a global view of the seasonal evolution of Titan's atmosphere over the poles. We leave the detailed comparison with the Imaging Science Subsystem (ISS) and the Composite Infrared Spectrometer (CIRS) data sets to further studies. We have computed global hyperspectral mosaics for each of the 127 targeted flybys of Titan to produce synthetic color maps emphasizing the main atmospheric features. The north pole appears fully covered by a huge cloud as soon as the first observations in 2004 and up to the equinox in 2009 (Le Mouélic et al., 2012). The northern skies then became progressively clearer, after the circulation turnover in 2009, revealing the underlying lakes and seas to the optical instruments up to 2017. The reverse situation is observed over the south pole, which was mostly clear of such a high obscuring cloud during the first years of the mission, but started to develop a polar cloud in 2012. This feature grew up month after month until the end of the mission in 2017, with a poleward latitudinal extent of 75 °S in 2013 up to 58 °S in April 2017. Thanks to the spectral capabilities of VIMS, we have detected HCN spectral signatures over the north pole in almost all flybys between 2004 and 2008. These HCN signatures started then to show up over the south pole in almost all flybys between 2012 and 2017, so perfectly matching the timing and spatial extent of the northern and southern polar atmospheric features.

  17. HRDI Observations of Inertia-Gravity Waves in the Mesosphere and Lower Thermosphere

    NASA Technical Reports Server (NTRS)

    Lieberman, Ruth S.

    1999-01-01

    Vertical profiles of High-resolution Doppler imager (HRDI) mesospheric winds have small-scale structure (vertical wavelengths between 10 and 20 km) that is virtually always present. Fourier analysis of HRDI zonal and meridional wind profiles have been carried out, and the spectral characteristics are sorted by latitude, month and local time. Power spectral density (PSD) exhibits a universal exp(-km) structure in the 10-20km wavelength regime, with K lying between 2 and 3. The observed PSD for wavelengths between 10 and 20 km is a factor of 3 higher than a null spectrum constructed from HRDI reported error bars multiplied by randomly varying numbers between -1 and +1. Stokes parameters were consolidated by month into Northern and Southern hemisphere middle and high latitudes belts (40-72 degrees), tidal belts (32-16 degrees) and a tropical belt (8S-8N). Vertical waves between 10 and 15 km in wavelength are about 10-15% polarized everywhere. The inferred propagation direction in the middle and high latitude Southern hemisphere is predominantly meridional during solstice, and significantly more zonal during equinoxes. In the tropical belt, the wave orientations are nearly North-South during solstices, with a slightly higher east-west component during equinox. In the tidal belts where the background wind includes a strong meridional tidal wind, the preferred wave orientation has a significant zonal component during equinox. These findings are consistent with the interpretation of wave filtering by the background wind.

  18. Heterologous expression of wheat VERNALIZATION 2 (TaVRN2) gene in Arabidopsis delays flowering and enhances freezing tolerance.

    PubMed

    Diallo, Amadou; Kane, Ndjido; Agharbaoui, Zahra; Badawi, Mohamed; Sarhan, Fathey

    2010-01-13

    The vernalization gene 2 (VRN2), is a major flowering repressor in temperate cereals that is regulated by low temperature and photoperiod. Here we show that the gene from Triticum aestivum (TaVRN2) is also regulated by salt, heat shock, dehydration, wounding and abscissic acid. Promoter analysis indicates that TaVRN2 regulatory region possesses all the specific responsive elements to these stresses. This suggests pleiotropic effects of TaVRN2 in wheat development and adaptability to the environment. To test if TaVRN2 can act as a flowering repressor in species different from the temperate cereals, the gene was ectopically expressed in the model plant Arabidopsis. Transgenic plants showed no alteration in morphology, but their flowering time was significantly delayed compared to controls plants, indicating that TaVRN2, although having no ortholog in Brassicaceae, can act as a flowering repressor in these species. To identify the possible mechanism by which TaVRN2 gene delays flowering in Arabidopsis, the expression level of several genes involved in flowering time regulation was determined. The analysis indicates that the late flowering of the 35S::TaVRN2 plants was associated with a complex pattern of expression of the major flowering control genes, FCA, FLC, FT, FVE and SOC1. This suggests that heterologous expression of TaVRN2 in Arabidopsis can delay flowering by modulating several floral inductive pathways. Furthermore, transgenic plants showed higher freezing tolerance, likely due to the accumulation of CBF2, CBF3 and the COR genes. Overall, our data suggests that TaVRN2 gene could modulate a common regulator of the two interacting pathways that regulate flowering time and the induction of cold tolerance. The results also demonstrate that TaVRN2 could be used to manipulate flowering time and improve cold tolerance in other species.

  19. Observations and modeling of northern mid-latitude recurring slope lineae (RSL) suggest recharge by a present-day martian briny aquifer

    NASA Astrophysics Data System (ADS)

    Stillman, David E.; Michaels, Timothy I.; Grimm, Robert E.; Hanley, Jennifer

    2016-02-01

    Recurring slope lineae (RSL) are narrow (0.5-5 m) dark features on Mars that incrementally lengthen down steep slopes, fade in colder seasons, and recur annually. These features have been identified from the northern to southern mid-latitudes. Here, we describe how observations of northern mid-latitude RSL in northern Chryse Planitia and southwestern Acidalia Planitia (CAP) suggest that brines start flowing before northern spring equinox and continue for more than half a Mars-year (490 ± 40 sols, spanning solar longitude 337° ± 11°-224° ± 20°). All CAP RSL are found on the steep slopes of craters and their source zones are at or below the elevation of the surrounding plains. Spacecraft-derived surface temperature observations cannot resolve individual RSL, so thermal modeling was used to determine that CAP RSL have a freezing temperature of 238-252 K, freeze and melt diurnally, and flow only occurs within the top ∼8 cm of the regolith. Furthermore, we calculate that a typical CAP RSL has a water budget of 1.5-5.6 m3/m of headwall. Therefore, such a large water budget makes annual recharge via atmospheric or subsurface diffusion sources unlikely. Alternatively, we hypothesize that the most plausible RSL source is a briny aquifer with a freezing temperature less than or equal to the mean annual CAP surface temperature (220-225 K). The annual cycle is as follows: in late autumn, the shallowest part of the brine feeding the source zone freezes, forming an ice dam. As spring approaches, temperatures rise and the dam is breached. Brine is discharged and the RSL initially lengthens rapidly (>1.86 m/sol), the lengthening rate then slows considerably, to ∼0.25 m/sol. Eventually, the losses equal the discharge rate and the RSL reaches its equilibrium phase. As brine flows in the RSL some of the water is lost to the atmosphere, therefore the freezing temperature of the brine within the RSL is higher (238-252 K) as the brine transitions to a super-eutectic salt

  20. Three Years of Monitoring Mars' Atmospheric Dust (Animation)

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site] Animation

    This movie shows the daily abundance of dust in the martian atmosphere over a period of three full martian years, from April 1999 through February 2005. The Thermal Emission Spectrometer instrument on NASA's Mars Global Surveyor orbiter has been tracking the weather on Mars for six years. The infrared spectrum observed by this instrument yields information about the spectral properties of the dust and the temperature of the atmosphere. These two properties can then be used to derive how much dust is in the atmosphere.

    Of particular interest are large regional and global dust storms that occur during summer in the southern hemisphere each Mars year. The 2001 storm was by far the largest, lasting over six months (June to October, 2001) and covering the entire planet. The storms in the other two Mars years shown here were much smaller and never covered the planet. The most recent storm season (June 2003 through January 2005) actually had two separate storms, one in June and a second in December. Unlike most large martian dust storms that start in the southern hemisphere, the December storm began in the north and swept toward the equator. Between storms the atmosphere becomes quite clear, with much smaller dust storms scattered throughout the year and over the planet.

    Seasons on Mars are determined by the position of Mars in its orbit around the Sun. The position is measured in degrees of solar longitude (Ls) around the orbit, beginning at 0 degrees Ls at the northern spring equinox, progressing to 90 degrees Ls at the start of northern summer, 180 degrees Ls at the fall equinox, 270 degrees Ls at the start of northern winter, and finally back to 360 degrees, or 0 degrees, Ls at the spring equinox. Dust abundance is measured as opacity (tau), with values of 0 tau representing a completely clear atmosphere, and values of 2 indicating that it is nearly impossible to see through to the surface

  1. East-west asymmetric of scintillation occurrence in Indonesia using GPS and GLONASS observations

    NASA Astrophysics Data System (ADS)

    Abadi, P.; Otsuka, Y.; Shiokawa, K.; Saito, S.; Husin, A.; Dear, V.; Anggarani, S.

    2015-12-01

    By using GNSS (Global Navigation Satellite Systems) receiver to collect amplitude scintillation at L1 frequency from GPS and GLONASS, we investigated ionospheric scintillation occurrence at equator anomaly in Indonesia from July 2014 to June 2015. The receiver is installed at Bandung (6.9 deg S, 107.6 deg E; 9.9 deg S mag. latitude), Indonesia. In this study, we grouped our analysis into two groups based on duration of observation, (1) July-December 2014 (monthly F10.7 ranged from 124.7-158.7) which is named autumn equinox and (2) January-June 2015 (monthly F10.7 ranged from 120.1-141.7) which is named spring equinox. Our preliminary results can be summarized as follows; (1) the intensity of scintillations at spring equinox is higher than at autumn equinox although solar activity at autumn equinox is higher than at spring equinox, see Figure 1 and (2) as shown in Figure 2, the directional distribution of scintillation occurrences at spring equinox mostly concentrate in the western sky, so we see east-west asymmetric, but the distribution at autumn equinox doesn't show clearly east-west asymmetric. Previous studies have reported that occurrence rate of the scintillation at spring equinox season is higher than at autumn equinox. Our results suggest that equinoctial asymmetry of scintillation occurrence can be also as an asymmetric of scintillation intensity and east-west asymmetric of scintillation occurrence between spring and autumn equinox. In general, plasma bubble is tilted westward as it vertically develop due to vertical shear in the eastward plasma drift in F region, and consequently, it will be tilted westward as it extends in latitude. Scintillation intensity will be stronger when signal propagation tend to be parallel with structure of the plasma bubble. Figure 2 also imply that the latitudinal extension of plasma bubble is higher at spring equinox than at autumn equinox. More the bubble extends in latitude, more the bubble structure exists in the western

  2. Association of barley photoperiod and vernalization genes with QTLs for flowering time and agronomic traits in a BC2DH population and a set of wild barley introgression lines

    PubMed Central

    Wang, Gongwei; Schmalenbach, Inga; von Korff, Maria; Léon, Jens; Kilian, Benjamin; Rode, Jeannette

    2010-01-01

    The control of flowering time has important impacts on crop yield. The variation in response to day length (photoperiod) and low temperature (vernalization) has been selected in barley to provide adaptation to different environments and farming practices. As a further step towards unraveling the genetic mechanisms underlying flowering time control in barley, we investigated the allelic variation of ten known or putative photoperiod and vernalization pathway genes between two genotypes, the spring barley elite cultivar ‘Scarlett’ (Hordeum vulgare ssp. vulgare) and the wild barley accession ‘ISR42-8’ (Hordeum vulgare ssp. spontaneum). The genes studied are Ppd-H1, VRN-H1, VRN-H2, VRN-H3, HvCO1, HvCO2, HvGI, HvFT2, HvFT3 and HvFT4. ‘Scarlett’ and ‘ISR42-8’ are the parents of the BC2DH advanced backcross population S42 and a set of wild barley introgression lines (S42ILs). The latter are derived from S42 after backcrossing and marker-assisted selection. The genotypes and phenotypes in S42 and S42ILs were utilized to determine the genetic map location of the candidate genes and to test if these genes may exert quantitative trait locus (QTL) effects on flowering time, yield and yield-related traits in the two populations studied. By sequencing the characteristic regions of the genes and genotyping with diagnostic markers, the contrasting allelic constitutions of four known flowering regulation genes were identified as ppd-H1, Vrn-H1, vrn-H2 and vrn-H3 in ‘Scarlett’ and as Ppd-H1, vrn-H1, Vrn-H2 and a novel allele of VRN-H3 in ‘ISR42-8’. All candidate genes could be placed on a barley simple sequence repeat (SSR) map. Seven candidate genes (Ppd-H1, VRN-H2, VRN-H3, HvGI, HvFT2, HvFT3 and HvFT4) were associated with flowering time QTLs in population S42. Four exotic alleles (Ppd-H1, Vrn-H2, vrn-H3 and HvCO1) possibly exhibited significant effects on flowering time in S42ILs. In both populations, the QTL showing the strongest effect corresponded to

  3. Getting back to nature: a reality check for experiments in controlled environments.

    PubMed

    Annunziata, Maria Grazia; Apelt, Federico; Carillo, Petronia; Krause, Ursula; Feil, Regina; Mengin, Virginie; Lauxmann, Martin A; Köhl, Karin; Nikoloski, Zoran; Stitt, Mark; Lunn, John E; Raines, Christine

    2017-07-20

    Irradiance from sunlight changes in a sinusoidal manner during the day, with irregular fluctuations due to clouds, and light-dark shifts at dawn and dusk are gradual. Experiments in controlled environments typically expose plants to constant irradiance during the day and abrupt light-dark transitions. To compare the effects on metabolism of sunlight versus artificial light regimes, Arabidopsis thaliana plants were grown in a naturally illuminated greenhouse around the vernal equinox, and in controlled environment chambers with a 12-h photoperiod and either constant or sinusoidal light profiles, using either white fluorescent tubes or light-emitting diodes (LEDs) tuned to a sunlight-like spectrum as the light source. Rosettes were sampled throughout a 24-h diurnal cycle for metabolite analysis. The diurnal metabolite profiles revealed that carbon and nitrogen metabolism differed significantly between sunlight and artificial light conditions. The variability of sunlight within and between days could be a factor underlying these differences. Pairwise comparisons of the artificial light sources (fluorescent versus LED) or the light profiles (constant versus sinusoidal) showed much smaller differences. The data indicate that energy-efficient LED lighting is an acceptable alternative to fluorescent lights, but results obtained from plants grown with either type of artificial lighting might not be representative of natural conditions. © The Author 2017. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  4. Seawifs Technical Report Series. Volume 2: Analysis of Orbit Selection for Seawifs: Ascending Versus Descending Node

    NASA Technical Reports Server (NTRS)

    Hooker, Stanford B. (Editor); Firestone, Elaine R. (Editor); Gregg, Watson W.

    1992-01-01

    Due to range safety considerations, the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) ocean color instrument may be required to be launched into a near-noon descending node, as opposed to the ascending node used by the predecessor sensor, the Coastal Zone Color Scanner (CZCS). The relative importance of ascending versus descending near-noon orbits was assessed here to determine if descending node will meet the scientific requirements of SeaWiFS. Analyses focused on ground coverage, local times of coverage, solar and viewing geometries (zenith and azimuth angles), and sun glint. Differences were found in the areas covered by individual orbits, but were not important when taken over a 16 day repeat time. Local time of coverage was also different: for ascending node orbits the Northern Hemisphere was observed in the morning and the Southern Hemisphere in the afternoon, while for descending node orbits the Northern Hemisphere was observed in the afternoon and the Southern in the morning. There were substantial differences in solar azimuth and spacecraft azimuth angles both at equinox and at the Northern Hemisphere summer solstice. Negligible differences in solar and spacecraft zenith angles, relative azimuth angles, and sun glint were obtained at the equinox. However, large differences were found in solar zenith angles, relative azimuths, and sun glint for the solstice. These differences appeared to compensate across the scan, however, an increase in sun glint in descending node over that in ascending node on the western part of the scan was compensated by a decrease on the eastern part of the scan. Thus, no advantage or disadvantage could be conferred upon either ascending node or descending node for noon orbits. Analyses were also performed for ascending and descending node orbits that deviated from a noon equator crossing time. For ascending node, afternoon orbits produced the lowest mean solar zenith angles in the Northern Hemisphere, and morning orbits produced

  5. Acute sensitivity of the vernal pool fairy shrimp, Branchinecta lynchi (Anostraca; Branchinectidae), and surrogate species to 10 chemicals

    USGS Publications Warehouse

    Ivey, Chris D.; Besser, John M.; Ingersoll, Christopher G.; Wang, Ning; Rogers, Christopher; Raimondo, Sandy; Bauer, Candice R.; Hammer, Edward J.

    2017-01-01

    Vernal pool fairy shrimp, Branchinecta lynchi, (Branchiopoda; Anostraca) and other fairy shrimp species have been listed as threatened or endangered under the US Endangered Species Act. Because few data exist about the sensitivity of Branchinecta spp. to toxic effects of contaminants, it is difficult to determine whether they are adequately protected by water quality criteria. A series of acute (24-h) lethality/immobilization tests was conducted with 3 species of fairy shrimp (B. lynchi, Branchinecta lindahli, and Thamnocephalus platyurus) and 10 chemicals with varying modes of toxic action: ammonia, potassium, chloride, sulfate, chromium(VI), copper, nickel, zinc, alachlor, and metolachlor. The same chemicals were tested in 48-h tests with other branchiopods (the cladocerans Daphnia magna and Ceriodaphnia dubia) and an amphipod (Hyalella azteca), and in 96-h tests with snails (Physa gyrina and Lymnaea stagnalis). Median effect concentrations (EC50s) for B. lynchi were strongly correlated (r2 = 0.975) with EC50s for the commercially available fairy shrimp species T. platyurus for most chemicals tested. Comparison of EC50s for fairy shrimp and EC50s for invertebrate taxa tested concurrently and with other published toxicity data indicated that fairy shrimp were relatively sensitive to potassium and several trace metals compared with other invertebrate taxa, although cladocerans, amphipods, and mussels had similar broad toxicant sensitivity. Interspecies correlation estimation models for predicting toxicity to fairy shrimp from surrogate species indicated that models with cladocerans and freshwater mussels as surrogates produced the best predictions of the sensitivity of fairy shrimp to contaminants. The results of these studies indicate that fairy shrimp are relatively sensitive to a range of toxicants, but Endangered Species Act-listed fairy shrimp of the genus Branchinecta were not consistently more sensitive than other fairy shrimp taxa. Environ Toxicol Chem

  6. Northern forests, Chapter 7

    Treesearch

    L.H. Pardo; C.L. Goodale; E.A. Lilleskov; L.H. Geiser

    2011-01-01

    The Northern Forests ecological region spans much of Canada, from Saskatchewan to Newfoundland; its southern portion extends into the northern United States (CEC 1997). The U.S. component includes the northern hardwood and spruce-fir forest types and encompasses parts of the Northeast (mountainous regions in Pennsylvania, New York, New Jersey, Connecticut,...

  7. Sweet vernal grasses (Anthoxanthum) colonized African mountains along two fronts in the Late Pliocene, followed by secondary contact, polyploidization and local extinction in the Pleistocene.

    PubMed

    Tusiime, Felly Mugizi; Gizaw, Abel; Wondimu, Tigist; Masao, Catherine Aloyce; Abdi, Ahmed Abdikadir; Muwanika, Vincent; Trávníček, Pavel; Nemomissa, Sileshi; Popp, Magnus; Eilu, Gerald; Brochmann, Christian; Pimentel, Manuel

    2017-07-01

    High tropical mountains harbour remarkable and fragmented biodiversity thought to a large degree to have been shaped by multiple dispersals of cold-adapted lineages from remote areas. Few dated phylogenetic/phylogeographic analyses are however available. Here, we address the hypotheses that the sub-Saharan African sweet vernal grasses have a dual colonization history and that lineages of independent origins have established secondary contact. We carried out rangewide sampling across the eastern African high mountains, inferred dated phylogenies from nuclear ribosomal and plastid DNA using Bayesian methods, and performed flow cytometry and AFLP (amplified fragment length polymorphism) analyses. We inferred a single Late Pliocene western Eurasian origin of the eastern African taxa, whose high-ploid populations in one mountain group formed a distinct phylogeographic group and carried plastids that diverged from those of the currently allopatric southern African lineage in the Mid- to Late Pleistocene. We show that Anthoxanthum has an intriguing history in sub-Saharan Africa, including Late Pliocene colonization from southeast and north, followed by secondary contact, hybridization, allopolyploidization and local extinction during one of the last glacial cycles. Our results add to a growing body of evidence showing that isolated tropical high mountain habitats have a dynamic recent history involving niche conservatism and recruitment from remote sources, repeated dispersals, diversification, hybridization and local extinction. © 2017 John Wiley & Sons Ltd.

  8. Seasonal Variation and Impact of Waste-Water Lagoons as Larval Habitat on the Population Dynamics of Culicoides sonorensis (Diptera:Ceratpogonidae) at Two Dairy Farms in Northern California

    PubMed Central

    Mayo, Christie E.; Osborne, Cameron J.; Mullens, Bradley A.; Gerry, Alec C.; Gardner, Ian A.; Reisen, William K.; Barker, Christopher M.; MacLachlan, N. James

    2014-01-01

    The Sacramento (northern Central) Valley of California (CA) has a hot Mediterranean climate and a diverse ecological landscape that is impacted extensively by human activities, which include the intensive farming of crops and livestock. Waste-water ponds, marshes, and irrigated fields associated with these agricultural activities provide abundant larval habitats for C. sonorensis midges, in addition to those sites that exist in the natural environment. Within this region, C. sonorensis is an important vector of bluetongue (BTV) and related viruses that adversely affect the international trade and movement of livestock, the economics of livestock production, and animal welfare. To characterize the seasonal dynamics of immature and adult C. sonorensis populations, abundance was monitored intensively on two dairy farms in the Sacramento Valley from August 2012– to July 2013. Adults were sampled every two weeks for 52 weeks by trapping (CDC style traps without light and baited with dry-ice) along N-S and E-W transects on each farm. One farm had large operational waste-water lagoons, whereas the lagoon on the other farm was drained and remained dry during the study. Spring emergence and seasonal abundance of adult C. sonorensis on both farms coincided with rising vernal temperature. Paradoxically, the abundance of midges on the farm without a functioning waste-water lagoon was increased as compared to abundance on the farm with a waste-water lagoon system, indicating that this infrastructure may not serve as the sole, or even the primary larval habitat. Adult midges disappeared from both farms from late November until May; however, low numbers of parous female midges were detected in traps set during daylight in the inter-seasonal winter period. This latter finding is especially critical as it provides a potential mechanism for the “overwintering” of BTV in temperate regions such as northern CA. Precise documentation of temporal changes in the annual abundance and

  9. Seasonal variation and impact of waste-water lagoons as larval habitat on the population dynamics of Culicoides sonorensis (Diptera:Ceratpogonidae) at two dairy farms in northern California.

    PubMed

    Mayo, Christie E; Osborne, Cameron J; Mullens, Bradley A; Gerry, Alec C; Gardner, Ian A; Reisen, William K; Barker, Christopher M; Maclachlan, N James

    2014-01-01

    The Sacramento (northern Central) Valley of California (CA) has a hot Mediterranean climate and a diverse ecological landscape that is impacted extensively by human activities, which include the intensive farming of crops and livestock. Waste-water ponds, marshes, and irrigated fields associated with these agricultural activities provide abundant larval habitats for C. sonorensis midges, in addition to those sites that exist in the natural environment. Within this region, C. sonorensis is an important vector of bluetongue (BTV) and related viruses that adversely affect the international trade and movement of livestock, the economics of livestock production, and animal welfare. To characterize the seasonal dynamics of immature and adult C. sonorensis populations, abundance was monitored intensively on two dairy farms in the Sacramento Valley from August 2012- to July 2013. Adults were sampled every two weeks for 52 weeks by trapping (CDC style traps without light and baited with dry-ice) along N-S and E-W transects on each farm. One farm had large operational waste-water lagoons, whereas the lagoon on the other farm was drained and remained dry during the study. Spring emergence and seasonal abundance of adult C. sonorensis on both farms coincided with rising vernal temperature. Paradoxically, the abundance of midges on the farm without a functioning waste-water lagoon was increased as compared to abundance on the farm with a waste-water lagoon system, indicating that this infrastructure may not serve as the sole, or even the primary larval habitat. Adult midges disappeared from both farms from late November until May; however, low numbers of parous female midges were detected in traps set during daylight in the inter-seasonal winter period. This latter finding is especially critical as it provides a potential mechanism for the "overwintering" of BTV in temperate regions such as northern CA. Precise documentation of temporal changes in the annual abundance and

  10. Summer at Saturn's North Pole: Seasonal Changes Seen by ISS & CIRS on Cassini, and VLT on the Ground

    NASA Astrophysics Data System (ADS)

    Sayanagi, K. M.; Blalock, J.; Fletcher, L. N.; Ingersoll, A. P.; Dyudina, U.; Ewald, S. P.

    2016-12-01

    We report seasonal changes in Saturn's north polar vortex seen by Cassini ISS, Cassini CIRS, and ground-based VLT VISIR thermal infrared observations. ISS observation of Saturn's northern high latitudes show that a reflective, bright polar spot has formed over the north pole, seen first in images captured in 2016. This coincides with the warm cyclonic north polar vortex that has been steadily warming since it was first discovered in 2007 by Cassini CIRS. The reflective spot was not present when the north pole was observed during the previous period of Cassini spacecraft's high-inclination orbits in 2012. In 2012, the concentration of light-scattering aerosols within 2-degree latitude of the north pole appeared to be less than that of the surrounding region, and appeared dark in all ISS filters. The new bright spot over the north pole is similar to that over the south pole seen in 2007. In 2007, Saturn was approaching the equinox of 2009 and south pole had been continuously illuminated since the previous equinox in 1995. The bright spot over the summer south pole in 2007 was hypothesized to consist of aerosols produced by ultraviolet photodissociation of hydrocarbon molecules; we follow this hypothesis to propose that the new bright spot over the north pole is also produced by the same mechanism. We argue that, in 2012 (3 years after equinox), the north polar bright spot hadn't formed because the ultraviolet insolation was not sufficient to produce enough photochemical aerosols. The new polar bright cloud formation is consistent with the rising abundances of stratospheric hydrocarbons (potential precursors to aerosol formation) over the north polar region as tracked by CIRS (Fletcher et al., 2015). In addition to ISS images, we also present CIRS and VLT-VISIR thermal maps of the northern high latitudes as the new north polar bright spot is expected to have implications on radiative energy balance. Our research has been supported by the Cassini Project, NASA grants

  11. Further study on the solar activity variation of daytime NmF2

    NASA Astrophysics Data System (ADS)

    Chen, Yiding; Liu, Libo

    2010-12-01

    The ionosonde observations in the East Asia-Australia sector are collected to further investigate the solar activity variation of daytime (0800 ˜ 1600 LT) NmF2. The linear increase rate of NmF2 with F10.7 at lower solar activity levels is remarkably dependent on latitude, season, and local time. The rate is largest in equinoxes (with an equinoctial asymmetry) and higher in the morning (afternoon) in local winter (summer) at geomagnetic midlatitudes; particularly, the maximum rates in local winter are obviously larger than those in local summer at northern midlatitudes. In the equatorial ionization anomaly (EIA) crest regions, the rates in equinoxes and December (June) solstice are remarkably higher than those in June (December) solstice at the northern (southern) EIA crest, and the rate grows from the morning sector to the afternoon sector. The variation trend of NmF2 with F10.7 also shows latitudinal, seasonal, and local time dependences. The saturation effect dominates in all seasons in the EIA regions; at midlatitudes, NmF2 nearly increases linearly with F10.7 in local winter so that a linear fit is a good approximation for NmF2 modeling, while the saturation effect still dominates in other seasons. The saturation effect is more significant in the afternoon, and the strongest saturation effect appears at the EIA crest latitudes in equinox afternoon. Discussions indicate that the variations of neutral atmosphere and hmF2 are responsible for the seasonal and local time dependences of the linear increase rate of NmF2 with F10.7 at midlatitudes, and the seasonal variation of neutral atmosphere is the primary reason for the seasonal dependence of the variation trend of NmF2 with F10.7, while dynamics processes are the more important factors controlling the linear increase rate and the variation trend of NmF2 with F10.7 at low latitudes. Furthermore, dynamics processes are important for the saturation effect, and the fountain effect is related to the strongest

  12. Seasonal variation and dynamics of Saturn's magnetospheric plasma, after 8 years of Cassini in orbit.

    NASA Astrophysics Data System (ADS)

    Sergis, N.

    2012-12-01

    Saturn orbits the Sun with a period of nearly 29.5 years and has an obliquity of 26.73°. As a result, Saturn presents seasonal variations similar to Earth's, but with much longer seasons, as the tilt between the planet's spin axis and the solar wind vary (approximately sinusoidally) with time between solstices. Saturn was close to its equinox (tilt below 8.1°) during the Pioneer 11 and Voyager 1 and 2 flybys that took place between September 1979 and August 1981, so any seasonal effects would have been relatively hard to see in the limited data from these missions. More than 2 decades later, on July 4, 2004, Cassini began orbiting Saturn, returning a variety of in situ and remote measurements. During the last 8 years, Cassini covered a large part of the Saturnian system and offered the opportunity of sampling the planetary magnetosphere not just at different seasons, but also at seasonal phases that are symmetric to the Saturnian equinox (August 2009). In this talk, we focus on the seasonal effects seen in the magnetosphere of Saturn as the angle between the solar wind flow and the Saturn-Sun direction changes from +23.7° (northern hemisphere winter) at the arrival of Cassini, to -14.9° (northern hemisphere summer) on July 2012. Particle and magnetic field data taken from a extensive set of equatorial and high latitude orbits of Cassini, at various distances and local times, show that: (a) the plasma sheet of Saturn has the form of a magnetodisk, with an energy-dependent vertical structure, being thicker by a factor of ~2 in the energetic particle range than in the electron plasma, and (b) it exhibits intense dynamical behavior, evident in in-situ particle measurements but also in energetic neutral atom (ENA) emissions. The study of the pre-equinox high latitude orbits revealed that the night side plasma sheet was tilted northward beyond a radial distance of ~15 Rs (1Rs=60,258 km). As equinox approached, Cassini observed a clear decrease in the tilt of the

  13. Patterns of testosterone in three Nearctic-Neotropical migratory songbirds during spring passage.

    PubMed

    Covino, Kristen M; Morris, Sara R; Moore, Frank R

    2015-12-01

    Preparation for breeding may overlap extensively with vernal migration in long-distance migratory songbirds. Testosterone plays a central role in mediating this transition into breeding condition by facilitating changes to physiology and behavior. While changes in testosterone levels are well studied in captive migrants, these changes are less well known in free-living birds. We examined testosterone levels in free-living Nearctic-Neotropical migrants of three species during their vernal migration. Testosterone levels increased during the migratory period in males of all three species but significantly so in only two. Testosterone levels in females remained the same throughout their migration. Our results support the extensive overlap between vernal migration and breeding preparation in male songbirds. The pattern of testosterone changes during vernal migration is far from clear in females. Copyright © 2015 Elsevier Inc. All rights reserved.

  14. Aerosols optical properties in Titan's detached haze layer before the equinox

    NASA Astrophysics Data System (ADS)

    Seignovert, Benoît; Rannou, Pascal; Lavvas, Panayotis; Cours, Thibaud; West, Robert A.

    2017-08-01

    UV observations with Cassini ISS Narrow Angle Camera of Titan's detached haze is an excellent tool to probe its aerosols content without being affected by the gas or the multiple scattering. Unfortunately, its low extent in altitude requires a high resolution calibration and limits the number of images available in the Cassini dataset. However, we show that it is possible to extract on each profile the local maximum of intensity of this layer and confirm its stability at 500 ± 8 km during the 2005-2007 period for all latitudes lower than 45°N. Using the fractal aggregate scattering model of Tomasko et al. (2008) and a single scattering radiative transfer model, it is possible to derive the optical properties required to explain the observations made at different phase angles. Our results indicates that the aerosols have at least ten monomers of 60 nm radius, while the typical tangential column number density is about 2 · 1010 agg m-2. Moreover, we demonstrate that these properties are constant within the error bars in the southern hemisphere of Titan over the observed time period. In the northern hemisphere, the size of the aerosols tends to decrease relatively to the southern hemisphere and is associated with a higher tangential opacity. However, the lower number of observations available in this region due to the orbital constraints is a limiting factor in the accuracy of these results. Assuming a fixed homogeneous content we notice that the tangential opacity can fluctuate up to a factor 3 among the observations at the equator. These variations could be linked with short scale temporal and/or longitudinal events changing the local density of the layer.

  15. Cassini-Huygens Science Highlights: Surprises in the Saturn System

    NASA Astrophysics Data System (ADS)

    Spilker, Linda; Altobelli, Nicolas; Edgington, Scott

    2014-05-01

    The Cassini-Huygens mission has greatly enhanced our understanding of the Saturn system. Fundamental discoveries have altered our views of Saturn, its retinue of icy moons including Titan, the dynamic rings, and the system's complex magnetosphere. Launched in 1997, the Cassini-Huygens spacecraft spent seven years traveling to Saturn, arriving in July 2004, roughly two years after the northern winter solstice. Cassini has orbited Saturn for 9.5 years, delivering the Huygens probe to its Titan landing in 2005, crossing northern equinox in August 2009, and completing its Prime and Equinox Missions. It is now three years into its 7-year Solstice mission, returning science in a previously unobserved seasonal phase between equinox and solstice. As it watches the approach of northern summer, long-dark regions throughout the system become sunlit, allowing Cassini's science instruments to probe as-yet unsolved mysteries. Key Cassini-Huygens discoveries include icy jets of material streaming from tiny Enceladus' south pole, lakes of liquid hydrocarbons and methane rain on giant Titan, three-dimensional structures in Saturn's rings, and curtain-like aurorae flickering over Saturn's poles. The Huygens probe sent back amazing images of Titan's surface, and made detailed measurements of the atmospheric composition, structure and winds. Key Cassini-Huygens science highlights will be presented. The Solstice Mission continues to provide new science. First, the Cassini spacecraft observes seasonally and temporally dependent processes on Saturn, Titan, Enceladus and other icy satellites, and within the rings and magnetosphere. Second, it addresses new questions that have arisen during the mission thus far, for example providing qualitatively new measurements of Enceladus and Titan that could not be accommodated in the earlier mission phases. Third, it will conduct a close-in mission at Saturn yielding fundamental knowledge about the interior of Saturn. This grand finale of the

  16. Titan's Stratospheric Condensibles at High Northern Latitudes During Northern Winter

    NASA Technical Reports Server (NTRS)

    Anderson, Carrie; Samuelson, R.; Achterberg, R.

    2012-01-01

    The Infrared Interferometer Spectrometer (IRIS) instrument on board Voyager 1 caught the first glimpse of an unidentified particulate feature in Titan's stratosphere that spectrally peaks at 221 per centimeter. Until recently, this feature that we have termed 'the haystack,' has been seen persistently at high northern latitudes with the Composite Infrared Spectrometer (CIRS) instrument onboard Cassini, The strength of the haystack emission feature diminishes rapidly with season, becoming drastically reduced at high northern latitudes, as Titan transitions from northern winter into spring, In contrast to IRIS whose shortest wavenumber was 200 per centimeter, CIRS extends down to 10 per centimeter, thus revealing an entirely unexplored spectral region in which nitrile ices have numerous broad lattice vibration features, Unlike the haystack, which is only found at high northern latitudes during northern winter/early northern spring, this geometrically thin nitrile cloud pervades Titan's lower stratosphere, spectrally peaking at 160 per centimeter, and is almost global in extent spanning latitudes 85 N to 600 S, The inference of nitrile ices are consistent with the highly restricted altitude ranges over which these features are observed, and appear to be dominated by a mixture of HCN and HC3N, The narrow range in altitude over which the nitrile ices extend is unlike the haystack, whose vertical distribution is significantly broader, spanning roughly 70 kilometers in altitude in Titan's lower stratosphere, The nitrile clouds that CIRS observes are located in a dynamically stable region of Titan's atmosphere, whereas CH4 clouds, which ordinarily form in the troposphere, form in a more dynamically unstable region, where convective cloud systems tend to occur. In the unusual situation where Titan's tropopause cools significantly from the HASI 70.5K temperature minimum, CH4 should condense in Titan's lower stratosphere, just like the aforementioned nitrile clouds, although

  17. High-altitude searches for vulcanoids: Observations from F/A-18B aircraft

    NASA Astrophysics Data System (ADS)

    Durda, D. D.; Stern, S. A.

    2003-05-01

    We have conducted a high-altitude observing campaign to search for vulcanoids, a population of small, asteroid-like bodies hypothesized to reside in the dynamically stable region interior to Mercury's orbit (i.e., orbits with aphelia <0.21 AU). This airborne search campaign utilized our versatile and highly capable SWUIS-A (Southwest Universal Imaging System - Airborne) instrument flown with SwRI flight astronomers to an altitude of 49,000 ft MSL aboard NASA F/A-18B aircraft in order to obtain darker twilight conditions for near-Sun observing than are possible from the ground. The first observing run (3 nights) was successfully completed at NASA's Dryden Flight Research Center during the March/April 2002 vernal equinox observing opportunity; the second observing run (3 nights) was completed during the September 2002 autumnal equinox observing opportunity. On each of the three evening and three morning twilight flights we recorded image data covering 250 square degrees of sky centered on the ecliptic from solar elongations of 6-18 deg. Reduction of the Mar/Apr and Sep 2002 data sets demonstrates that we are reliably detecting objects to magnitude V = 9.5-11 at 15-20 degrees solar elongation. This is significantly fainter than the instrument would have performed from the ground and comparable to the faintest stars visible in our space-based SOHO LASCO C3 coronagraph vulcanoids search (Durda et al. 2000; Icarus 148, 312-315). The SWUIS-A instrument itself is capable of imaging objects as faint as magnitude V = 13, corresponding to vulcanoids less than 10 km across, with a sufficiently dark sky background. For reference, V = 10 corresponds to a 18-km diameter object 1 AU from Earth and 0.15 AU from the sun with a Mercury-like geometric albedo of 14%. No vulcanoid candidates have been detected in the 49,000-ft altitude airborne observations to date. We thank NASA research pilots Rick Searfoss, Frank Batteas, Craig Bomben, and Dana Purifoy. This research is supported by

  18. Northern Pintail

    USGS Publications Warehouse

    Clark, Robert G.; Fleskes, Joseph P.; Guyn, Karla L.; Haukos, David A.; Austin, Jane E.; Miller, Michael R.

    2014-01-01

    This medium-sized dabbling duck of slender, elegant lines and conservative plumage coloration is circumpolar in distribution and abundant in North America, with core nesting habitat in Alaska and the Prairie Pothole Region of southern Canada and the northern Great Plains. Breeders favor shallow wetlands interspersed throughout prairie grasslands or arctic tundra. An early fall migrant, the species arrives on wintering areas beginning in August, after wing molt, often forming large roosting and feeding flocks on open, shallow wetlands and flooded agricultural fields. The birds consume grains, marsh plant seeds, and aquatic invertebrates throughout fall and winter.Northern Pintails are among the earliest nesting ducks in North America, beginning shortly after ice-out in many northern areas. Individuals form new pair bonds each winter but are highly promiscuous during the nesting season, with mated and unmated males often involved in vigorous, acrobatic Pursuit Flights. Annual nest success and productivity vary with water conditions, predation, and weather. Females build nests on the ground, often far from water. Only the female incubates; her mate leaves shortly after incubation begins. Ducklings hatch together in one day, follow the female to water after a day in the nest, and fledge by July or August. Adults and ducklings consume mainly aquatic invertebrates during the breeding season.Predators and farming operations destroy many thousands of Northern Pintail nests annually; farming has also greatly reduced the amount of quality nesting cover available. Winter habitats are threatened by water shortages, agricultural development, contamination, and urbanization. Periods of extended drought in prairie nesting regions have caused dramatic population declines, usually followed by periods of recovery. Over the long term, however, the continental population of Northern Pintails has declined significantly from 6 million birds in the early 1970s to less than 3 million in

  19. Atopy and serum eosinophil cationic protein in 110 white children with vernal keratoconjunctivitis: differences between tarsal and limbal forms.

    PubMed

    Pucci, N; Novembre, E; Lombardi, E; Cianferoni, A; Bernardini, R; Massai, C; Caputo, R; Campa, L; Vierucci, A

    2003-03-01

    A predominance of Th2 response has been suggested in vernal keratoconjunctivitis (VKC), and a high prevalence of IgE-sensitized (IgE-S) patients has been reported (positive skin prick test or serum-specific-IgE). Palpebral and bulbar VKC are considered to be expressions of the same disease and only occasional racial and histopathological differences are described between the two forms. Tear levels of eosinophil cationic proteins have been correlated with the severity of ocular symptoms; however, there is no published study that demonstrates the presence of serum markers of disease activity. This study was performed to evaluate the prevalence of IgE-sensitization in palpebral, bulbar and mixed VKC and to determine possible useful markers of disease activity in peripheral circulation. A total of 110 white VKC patients (mean age 8.3 years, range 3.2-18 years) were evaluated for ocular score in the active phase of the disease. Skin prick tests and serum-specific IgE for common allergens, serum-total IgE, peripheral blood eosinophil counts (PBECs) and serum eosinophil cationic protein (s-ECP) were determined. Fifteen age-matched non-IgE-S control children underwent the same determinations. s-ECP, PBECs and s-total IgE were significantly higher in IgE-S than in non-IgE-S VKC patients and in non-IgE-S VKC patients than in controls. A lower prevalence of IgE-S patients was found in bulbar vs. tarsal (P = 0. 050) or mixed forms (P = 0.002). The score of giant papillae was strongly correlated with s-ECP levels (P < 0.001) and with PBECs (P = 0.001). Our data suggest that an overall eosinophilic response is present in VKC independently of IgE-sensitization; bulbar forms, unlike tarsal and mixed forms, were associated with a low prevalence of IgE-sensitization. Serum ECP was a useful marker of disease activity in tarsal and mixed forms.

  20. Concerning the Motion of FTEs and Attendant Signatures

    NASA Technical Reports Server (NTRS)

    Sibeck, David G.

    2010-01-01

    We employ the Cooling et al. [2001] model to predict the location, orientation, and motion of flux transfer events (FTEs) generated along finite length component and anti parallel reconnection lines for typical solar wind plasma conditions and various interplanetary magnetic field (IMF) orientations in the plane perpendicular to the SunEarth line at the solstices and equinoxes. For duskward and northward or southward IMF orientations, events formed by component reconnection originate along reconnection curves passing through the sub solar point that tilt from southern dawn to northern dusk. They maintain this orientation as they move either northward into the northern dawn quadrant or southward into the southern dusk quadrant. By contrast, events formed by antiparallel reconnection originate along reconnection curves running from northern dawn to southern dusk in the southern dawn and northern dusk quadrants and maintain these orientations as they move anti sunward into both these quadrants. Although both the component and antiparallel reconnection models can explain previously reported event orientations on the southern dusk magnetopause during intervals of northward and dawn ward IMF orientation, only the component model explains event occurrence near the subsolar magnetopause during intervals when the IMF does not point due southward.

  1. Variations of the ionospheric parameters and vertical electron density distribution at the northern edge of the EIA from 2010 to 2015 along 95°E and comparison with the IRI-2012

    NASA Astrophysics Data System (ADS)

    Kalita, Bitap Raj; Bhuyan, Pradip Kumar

    2017-07-01

    The vertical electron density profiles over Dibrugarh (27.5°N, 95°E, 43° dip) a low mid latitude station normally located at the northern edge of the EIA for the period of July 2010 till October 2015 are constructed from the measured bottom side profiles and ionosonde-GPS TEC assisted Topside Sounder Model (TSM) topside profiles. The bottom side density profiles are obtained by using POLAN on the manually scaled ionograms. The topside is constructed by the modified ionosonde assisted TSM model (TaP-TSM assisted by POLAN) which is integrated with POLAN for the first time. The reconstructed vertical profile is compared with the IRI predicted density profile and the electron density profile obtained from the COSMIC/FORMOSAT radio occultation measurements over Dibrugarh. The bottom side density profiles are fitted to the IRI bottom side function to obtain best-fit bottom side thickness parameter B0 and shape parameter B1. The temporal and solar activity variation of the B-parameters over Dibrugarh are investigated and compared to those predicted by IRI-2012 model with ABT-2009 option. The bottom side thickness parameter B0 predicted by the IRI model is found to be similar to the B0 measured over Dibrugarh in the night time and the forenoon hours. Differences are observed in the early morning and the afternoon period. The IRI doesn't reproduce the morning collapse of B0 and overestimates the B0 over Dibrugarh in the afternoon period, particularly in summer and equinox. The IRI model predictions are closest to the measured B0 in the winter of low solar activity. The B0 over Dibrugarh is found to increase by about 15% with solar activity during the period of study encompassing almost the first half of solar cycle 24 but solar activity effect was not observed in the B1 parameter. The topside profile obtained from TaP profiler is thicker than the IRI topside in equinox from afternoon to sunrise period but is similar to the IRI in summer daytime. The differences in the

  2. The Creatures beneath Our Feet: Amphibian Monitors Take to the Road.

    ERIC Educational Resources Information Center

    Daigle, Cheryl Perusse

    1999-01-01

    The Nature Conservancy's Berkshire Program involves community volunteers in monitoring migration routes of amphibians that rely on vernal pools for breeding success. Vernal-pool workshops provide basic knowledge of amphibian lifecycles and detailed monitoring instructions. Nighttime field trips for adults and children and monitoring experiences…

  3. Reproductive performance of donor mares subsequent to eFSH treatment in early vernal transition: Comparison between the first, second, and mid-season estrous cycles of the breeding season.

    PubMed

    Raz, Tal; Hunter, Barbara; Carley, Sylvia; Card, Claire

    2009-11-01

    The objective was to compare the reproductive performances associated with the first (Cycle-1), second (Cycle-2), and mid-season (MS-Cycle) ovulations of the breeding season in donor mares that were treated with equine-FSH (eFSH) in the early vernal transition. Mares (n=15) kept under ambient light were examined ultrasonographically per-rectum starting January 30. When an ovarian follicle > or =25mm in diameter was detected, twice daily eFSH treatments were initiated. The eFSH treatments ceased when a follicle > or =35mm was detected, and 36h later hCG was administered. Thereafter, mares were artificially inseminated every 48h until ovulation (Day 0). Trans-cervical embryo recovery attempts were performed on Day 8, and subsequently PGF2alpha was administered. Equine FSH was not administered in the subsequent estrous cycles. In Cycle-2 and in the MS-Cycle, hCG was administered when a follicle > or =35mm was detected; breeding, embryo recovery, and PGF2alpha administration, were similar to Cycle-1. Mares had an untreated estrous cycle (no treatment or breeding) between Cycle-2 and the MS-Cycle. All mares developed follicle(s) > or =35mm after 4.9+/-0.6 days of eFSH treatment, and subsequently ovulations occurred; mean (95% CI) interval from treatment initiation to ovulation was 7.9 (6.5-9.3) days. The number of preovulatory follicles (> or =30mm) at the time of hCG administration (Cycle-1: 2.2+/-0.3 compared with Cycle-2: 1.0+/-0 compared with MS-Cycle: 1.1+/-0.1 follicles), and the number of ovulations (2.5+/-0.4 compared with 1.0+/-0 compared with 1.1+/-0.1 ovulations) were greater (p<0.05) in Cycle-1. Nevertheless, mean embryo numbers did not differ among cycles (0.8+/-0.2 compared with 0.5+/-0.1 compared with 0.5+/-0.1 embryo/mare). On average, embryo morphology grade was less (p<0.05) in Cycle-1 as compared to non-eFSH cycles (combined Cycle-2 and MS-Cycle). This impaired embryo quality could be due to a seasonal effect, or negative effect of the eFSH treatment

  4. Comparison of northern goshawk nesting habitat in Appalachian oak and northern hardwood forests of Pennsylvania

    Treesearch

    J.T. Kimmel; R.H. Yahner

    1991-01-01

    The Northern Goshawk (Accipiter gentilis) is a rare to uncommon woodland raptor in Pennsylvania. Although it is primarily a boreal species, the goshawk nests in Northern Hardwoods and Appalachian oak forests along the southern margin of its range in Pennsylvania. This study compared the nesting habitat of goshawks in Appalachian oak and Northern...

  5. Acute sensitivity of the vernal pool fairy shrimp, Branchinecta lynchi (Anostraca; Branchinectidae), and surrogate species to 10 chemicals.

    PubMed

    Ivey, Chris D; Besser, John M; Ingersoll, Chris G; Wang, Ning; Rogers, D Christopher; Raimondo, Sandy; Bauer, Candice R; Hammer, Edward J

    2017-03-01

    Vernal pool fairy shrimp, Branchinecta lynchi, (Branchiopoda; Anostraca) and other fairy shrimp species have been listed as threatened or endangered under the US Endangered Species Act. Because few data exist about the sensitivity of Branchinecta spp. to toxic effects of contaminants, it is difficult to determine whether they are adequately protected by water quality criteria. A series of acute (24-h) lethality/immobilization tests was conducted with 3 species of fairy shrimp (B. lynchi, Branchinecta lindahli, and Thamnocephalus platyurus) and 10 chemicals with varying modes of toxic action: ammonia, potassium, chloride, sulfate, chromium(VI), copper, nickel, zinc, alachlor, and metolachlor. The same chemicals were tested in 48-h tests with other branchiopods (the cladocerans Daphnia magna and Ceriodaphnia dubia) and an amphipod (Hyalella azteca), and in 96-h tests with snails (Physa gyrina and Lymnaea stagnalis). Median effect concentrations (EC50s) for B. lynchi were strongly correlated (r 2  = 0.975) with EC50s for the commercially available fairy shrimp species T. platyurus for most chemicals tested. Comparison of EC50s for fairy shrimp and EC50s for invertebrate taxa tested concurrently and with other published toxicity data indicated that fairy shrimp were relatively sensitive to potassium and several trace metals compared with other invertebrate taxa, although cladocerans, amphipods, and mussels had similar broad toxicant sensitivity. Interspecies correlation estimation models for predicting toxicity to fairy shrimp from surrogate species indicated that models with cladocerans and freshwater mussels as surrogates produced the best predictions of the sensitivity of fairy shrimp to contaminants. The results of these studies indicate that fairy shrimp are relatively sensitive to a range of toxicants, but Endangered Species Act-listed fairy shrimp of the genus Branchinecta were not consistently more sensitive than other fairy shrimp taxa. Environ Toxicol

  6. Trophic ecology of largemouth bass and northern pike in allopatric and sympatric assemblages in northern boreal lakes

    USGS Publications Warehouse

    Soupir, Craig A.; Brown, Michael L.; Kallemeyn, Larry W.

    2000-01-01

    Largemouth bass (Micropterus salmoides) and northern pike (Esox lucius) are top predators in the food chain in most aquatic environments that they occupy; however, limited information exists on species interactions in the northern reaches of largemouth bass distribution. We investigated the seasonal food habits of allopatric and sympatric assemblages of largemouth bass and northern pike in six interior lakes within Voyageurs National Park, Minnesota. Percentages of empty stomachs were variable for largemouth bass (38-54%) and northern pike (34.7-66.7%). Fishes (mainly yellow perch, Perca flavescens) comprised greater than 60% (mean percent mass, MPM) of the northern pike diet during all seasons in both allopatric and sympatric assemblages. Aquatic insects (primarily Odonata and Hemiptera) were important in the diets of largemouth bass in all communities (0.0-79.7 MPM). Although largemouth bass were observed in the diet of northern pike, largemouth bass apparently did not prey on northern pike. Seasonal differences were observed in the proportion of aquatic insects (P = 0.010) and fishes (P = 0.023) in the diets of northern pike and largemouth bass. Based on three food categories, jackknifed classifications correctly classified 77 and 92% of northern pike and largemouth bass values, respectively. Percent resource overlap values were biologically significant (greater than 60%) during at least one season in each sympatric assemblage, suggesting some diet overlap.

  7. The variability of SE2 tide extracted from TIMED/SABER observations

    NASA Astrophysics Data System (ADS)

    Li, X.; Wan, W.; Ren, Z.

    2017-12-01

    Based on the temperature observations of the TIMED/SABER in mesosphere/lower thermosphere region (70-110 km altitudes) and at the low latitude and midlatitude (45°S-45°N) from 2002 to 2012, the variability of the nonmigrating tide SE2 with 1 day resolution is analyzed. It is found that the climatological features (large-scale variability) of the semidiurnal nonmigrating tide with zonal wave number 2 (SE2) tide are similar with the results from the previous research works. The SE2 tide manifests mainly at the low-mid latitudes around ±30°. The northern hemisphere tidal amplitudes below 110 km are larger than the southern hemisphere tide. SE2 peaks below 110 km mainly present between 100 and 110 km altitude. The tidal amplitudes below 110 km occur a north-south asymmetry about the equator in the annual variation: in the southern hemisphere, SE2 occurs with an obvious annual variation with a maximum of tidal amplitudes in December, while in the northern one, the semiannual variations with maximum at the equinoxes. Herein, owing to the high-resolution tidal data, we could research the short-term (day-to-day) variations of SE2. We found that the day-to-day variations manifest mainly at between 100 and 110 km altitudes; it increases gradually with latitudes, and it is stronger at the low-mid latitudes; it is relatively slightly stronger around solstices than equinoxes; and it does not present a remarkably interannual variation. The SE2 day-to-day variations may be composed by the absolute amplitudes' variance and the impact of the wave phases, and the latter ones are more important.

  8. Estimation of the heat/Na flux using lidar data recorded at ALO, Cerro Pachon, Chile

    NASA Astrophysics Data System (ADS)

    Vargas, F.; Gardner, C. S.; Liu, A. Z.; Swenson, G. R.

    2013-12-01

    In this poster, lidar nigh-time data are used to estimate the vertical fluxes of heat and Na at the mesopause region due to dissipating gravity waves presenting periods from 5 min to 8 h, and vertical wavelengths > 2 km. About 60 hours of good quality data were recorded near the equinox during two observation campaigns held in Mar, 2012 and Apr, 2013 at the Andes Lidar Observatory (30.3S,70.7W). These first measurements of the heat/Na flux in the southern hemisphere will be discussed and compared with those from the northern hemisphere stations obtained at the Starfire Optical Range, NM, and Maui, HW.

  9. Expert Perceptions of Approaches to Protecting Isolated Wetlands in the Northeastern United States

    Treesearch

    Kristin Floress; Mary Beth Kolozsvary; Jean Mangun

    2017-01-01

    In this article, we describe how protecting vernal pools was discussed by experts in the northeastern United States (U.S) within the context of a theoretical policy framework. We offer insight about characteristics of feasible vernal pool policy solutions, and identify gaps in our understanding, particularly regarding conditions in states currently lacking specific...

  10. Survival and growth of planted northern red oak in northern West Virginia

    Treesearch

    Charles A. McNeel; David M. Hix; Edwin C. Townsend

    1993-01-01

    The survival and growth of northern red oak (Quercus rubra L.) seedlings planted beneath a shelterwood in northern West Virginia were evaluated one year after planting. The use of 1.5 m (5 ft) tall TUBEX tree shelters on planted seedlings was also examined. The study was conducted on both excellent and good sites (site indices of 27 m (89 ft) and 22...

  11. Response of nesting northern goshawks to logging truck noise in northern Arizona

    Treesearch

    Teryl G. Grubb; Larry L. Pater; Angela E. Gatto; David K. Delaney

    2013-01-01

    We recorded 94 sound-response events at 3 adult-occupied northern goshawk (Accipiter gentilis) nests 78 m, 143 m, and 167m from the nearest United States Forest Service maintenance level 3, improved gravel road on the Kaibab Plateau in northern Arizona. During 4 test sessions on 7, 8, 10, and 11 June 2010, we recorded 60 experimentally controlled logging trucks; 30 non...

  12. Monitoring Physicochemical and Nutrient Dynamics Along a Development Gradient in Maine Ephemeral Wetlands

    NASA Astrophysics Data System (ADS)

    Podzikowski, L. Y.; Capps, K. A.; Calhoun, A.

    2014-12-01

    Vernal pools are ephemeral wetlands in forested landscapes that fill with snowmelt, precipitation, and/or groundwater in the spring, and characteristically dry down through the summer months. Typically, vernal pool research has focused on the population and community ecology of pool-breeding organisms (amphibians and macroinvertebrates) conducted during their relatively short breeding season. Yet, little is known about the temporal variability of biogeochemical processes within and among vernal pools in urbanizing landscapes. In this study, we monitored physicochemical characteristics and nutrient dynamics in 22 vernal pools in central Maine post thaw in 2014. Four pristine pools were sampled weekly in five locations within the pool for ambient nutrient concentrations (SRP, NH4, NOx) and at three locations for physicochemical characteristics (DO, pH, temperature, conductivity). In the remaining 18 pools, we sampled one location for nutrients and three locations for physicochemical characteristics at least monthly to estimate the influence of increasing urbanization on the physical and chemical environment. Our data suggest most pools found in urbanizing areas have higher conductivity (developed sites ranging 18.52 - 1238 μS cm-1 compared to pristine between 14.08 - 58.4 μS cm-1). Previous work suggests forested pools exhibit dystrophic conditions with high coloration from DOC limiting primary production due to increased light attenuation in pools. However, both pristine and urban pools experienced spikes in DO (>100% saturation) throughout the day, suggesting that high productivity is not a reliable indicator of the effects of urbanization on vernal pools. We argue that continued monitoring of vernal pools along a gradient of urbanization could give insight into the role of ephemeral wetlands as potential biogeochemical hotspots and may also indicate how human development may alter biogeochemical cycling in ephemeral wetlands.

  13. Fertilization of Northern Hardwoods

    Treesearch

    R. Lea; D.G. Brockway

    1986-01-01

    Northern hardwoods grow over a considerable range of climatic and edaphic conditions and exhibit a wide range in productivity.Many northern hardwood forests are capable of high production relative to other forest types, but are often slow to reach maximum productivity because of low nutrient availability.Altering the patterns of biomass accumulation so that managers...

  14. Adaptability of black walnut, black cherry, and Northern red oak to Northern California

    Treesearch

    Philip M. McDonald

    1987-01-01

    When planted in sheltered sites in northern California, only 49% of black walnut (Juglans nigra L.) and 58% of black cherry (Prunus serotina Ehrh.) survived for 15 years, and 20% of northern red oak (Quercus rubra L.) survived for 10 years. The black walnut trees averaged 0.6 inches diameter at breast...

  15. From the Northern Eurasia Earth Science Partnership Initiative to the Northern Eurasia Future Initiative

    NASA Astrophysics Data System (ADS)

    Streletskiy, D. A.; Groisman, P. Y.; Shugart, H. H., Jr.; Gulev, S.; Maksyutov, S. S.; Qi, J.

    2017-12-01

    Since 2004, the Northern Eurasia Earth Science Partnership Initiative (NEESPI) - an interdisciplinary program of internationally-supported Earth systems and science research - has addressed large-scale and long-term manifestations of climate and environmental changes over Northern Eurasia and their impact on the Global Earth system. With 40 books and more than 1500 peer-reviewed journal publications to its credit, NEESPI's output can now be used to directly support decision-making for societal needs. Specifically, it was decided to shift gradually the foci of regional studies in Northern Eurasia towards applications with the following major Science Question: "What dynamic and interactive change(s) will affect societal well-being, activities, and health, and what might be the mitigation and adaptation strategies that could support sustainable development and decision-making activities in Northern Eurasia?" To answer this question requires a stronger socio-economic component in the ongoing and future regional studies focused on sustainable societal development under changing climatic and environmental conditions. The NEESPI Research Team has reorganized itself into "Northern Eurasia Future Initiative" (NEFI) and developed a new Science Plan released in June 2016. The Plan underwent a 6-month-long public review and was finalized at the end of 2016. Its description was thereafter split between two review papers: Groisman et al. (2017) and Monier et al. (2017). The first paper describes the Plan rationale and a new set of topical questions. The second paper describes a major modeling approach that will be employed in addressing the "what to do" questions of the NEFI Research (cf., presentation by Monier et al. at this Session). In the current presentation, we outline the new NEFI research foci and present latest NEFI findings including international projects in the Eurasian Arctic, boreal zone, and the Dry Land Belt of Northern Eurasia (cf., also presentations at sister

  16. Movements of a polar bear from northern Alaska to northern Greenland

    USGS Publications Warehouse

    Durner, George M.; Amstrup, Steven C.

    1995-01-01

    Using satellite telemetry, we monitored the movements of an adult female polar bear (Ursus maritimus) as she traveled from the Alaskan Beaufort Sea coast to northern Greenland. She is the first polar bear known to depart the Beaufort Sea region for an extended period, and the first polar bear known to move between Alaska and Greenland. This bear traveled for four months across the polar basin and came within 2 degrees of the North Pole. During the first year following her capture, she traveled 5256 km. Evidence to suggest her use of maternity dens in northern Alaska and in northern Greenland demonstrates the potential for genetic exchange between two widely separate populations of polar bears. The long life spans of polar bears and the rarity of their long-range movements means the significance of interpopulation movement can be assessed after long-term monitoring of individuals.

  17. What are northern hardwoods?

    Treesearch

    Richard M. Godman

    1992-01-01

    The term "northern hardwoods" was used in the early 1900's to separate the hardwoods of the northern region from those growing in the South. With continued usage in the North the term now represents all dense hardwood species both in the Lake States and Northeast. Unfortunately, this has complicated describing and applying silvicultural practices for...

  18. Northern homelands, northern frontier: linking culture and economic security in contemporary livelihoods in boreal and cold temperate forest communities in northern Canada

    Treesearch

    Andrew J. Chapeskie

    2001-01-01

    This paper highlights the environmental pressures that have historically been brought to bear on the northern forests of Canada. It then presents the idea of the northern frontier forests of Canada as Indigenous landscapes whose ecological diversity and abundance have historically been nurtured in no small measure by their original inhabitants. It then proposes how...

  19. Seasonal Changes in Titan's Meteorology

    NASA Technical Reports Server (NTRS)

    Turtle, E. P.; DelGenio, A. D.; Barbara, J. M.; Perry, J. E.; Schaller, E. L.; McEwen, A. S.; West, R. A.; Ray, T. L.

    2011-01-01

    The Cassini Imaging Science Subsystem has observed Titan for 1/4 Titan year, and we report here the first evidence of seasonal shifts in preferred locations of tropospheric methane clouds. South \\polar convective cloud activity, common in late southern summer, has become rare. North \\polar and northern mid \\latitude clouds appeared during the approach to the northern spring equinox in August 2009. Recent observations have shown extensive cloud systems at low latitudes. In contrast, southern mid \\latitude and subtropical clouds have appeared sporadically throughout the mission, exhibiting little seasonality to date. These differences in behavior suggest that Titan s clouds, and thus its general circulation, are influenced by both the rapid temperature response of a low \\thermal \\inertia surface and the much longer radiative timescale of Titan s cold thick troposphere. North \\polar clouds are often seen near lakes and seas, suggesting that local increases in methane concentration and/or lifting generated by surface roughness gradients may promote cloud formation. Citation

  20. An empirical model of ionospheric total electron content (TEC) near the crest of the equatorial ionization anomaly (EIA)

    NASA Astrophysics Data System (ADS)

    Hajra, Rajkumar; Chakraborty, Shyamal Kumar; Tsurutani, Bruce T.; DasGupta, Ashish; Echer, Ezequiel; Brum, Christiano G. M.; Gonzalez, Walter D.; Sobral, José Humberto Andrade

    2016-07-01

    We present a geomagnetic quiet time (Dst > -50 nT) empirical model of ionospheric total electron content (TEC) for the northern equatorial ionization anomaly (EIA) crest over Calcutta, India. The model is based on the 1980-1990 TEC measurements from the geostationary Engineering Test Satellite-2 (ETS-2) at the Haringhata (University of Calcutta, India: 22.58° N, 88.38° E geographic; 12.09° N, 160.46° E geomagnetic) ionospheric field station using the technique of Faraday rotation of plane polarized VHF (136.11 MHz) signals. The ground station is situated virtually underneath the northern EIA crest. The monthly mean TEC increases linearly with F10.7 solar ionizing flux, with a significantly high correlation coefficient (r = 0.89-0.99) between the two. For the same solar flux level, the TEC values are found to be significantly different between the descending and ascending phases of the solar cycle. This ionospheric hysteresis effect depends on the local time as well as on the solar flux level. On an annual scale, TEC exhibits semiannual variations with maximum TEC values occurring during the two equinoxes and minimum at summer solstice. The semiannual variation is strongest during local noon with a summer-to-equinox variability of ~50-100 TEC units. The diurnal pattern of TEC is characterized by a pre-sunrise (0400-0500 LT) minimum and near-noon (1300-1400 LT) maximum. Equatorial electrodynamics is dominated by the equatorial electrojet which in turn controls the daytime TEC variation and its maximum. We combine these long-term analyses to develop an empirical model of monthly mean TEC. The model is validated using both ETS-2 measurements and recent GNSS measurements. It is found that the present model efficiently estimates the TEC values within a 1-σ range from the observed mean values.

  1. The variability of SE2 tide extracted from TIMED/SABER observations

    NASA Astrophysics Data System (ADS)

    Li, Xing; Wan, Weixing; Ren, Zhipeng; Yu, You

    2017-02-01

    Based on the temperature observations of the TIMED/Sounding of the Atmosphere using Broadband Emission Radiometry in mesosphere/lower thermosphere region (70-110 km altitudes) and at the low latitude and midlatitude (45°S-45°N) from 2002 to 2012, the variability of the nonmigrating tide SE2 with 1 day resolution is analyzed, using the method from Li et al. (2015). It is found that the climatological features (large-scale variability) of the SE2 tide are similar with the results from the previous research works. The SE2 tide manifests mainly at the low-mid latitudes around ±30°. The northern hemisphere tidal amplitudes below 110 km are larger than the southern hemisphere tide. SE2 peaks below 110 km mainly present between 100 and 110 km altitude. The tidal amplitudes below 110 km occur a north-south asymmetry about the equator in the annual variation: in the southern hemisphere, SE2 occurs with an obvious annual variation with a maximum of tidal amplitudes in December, while in the northern one, the semiannual variations with maximum at the equinoxes. Herein, owing to the high-resolution tidal data, we could research the short-term (day-to-day) variations of SE2. We found that the day-to-day variations manifest mainly at between 100 and 110 km altitudes; it increases gradually with latitudes, and it is stronger at the low-mid latitudes; it is relatively slightly stronger around solstices than equinoxes; and it does not present a remarkably interannual variation. The SE2 day-to-day variations may be composed by the absolute amplitudes' variance and the impact of the wave phases, and the latter ones are more important.

  2. Spatial and temporal variation in ephemeral pool crustacean communities

    Treesearch

    Janette Holtz; Marie A. Simovich; Thomas Philippi

    2005-01-01

    Vernal pool habitat losses in San Diego County, California, are estimated at 95 percent and will increase as development continues. The majority of San Diego’s remaining pools are located at the Marine Corps Air Station, Miramar. Crustacean communities in eight vernal pools in San Diego County were sampled over 3 years that differed in rainfall amount and pattern. In...

  3. Comparison with IRI-PLUS and IRI-2012-TEC values of GPS-TEC values

    NASA Astrophysics Data System (ADS)

    Atıcı, Ramazan; Saǧır, Selçuk

    2016-07-01

    This study presents a comparison with IRI-PLUS and IRI-2012 Total Electron Content (TEC) values of Total Electron Content (TEC) values obtained from Ankara station (39,7 N; 32,76 E) of Global Position System (GPS) of Turkey on equinox and solstice days of 2009 year. For all days, it is observed that GPS-TEC values are greater than IRI-2012-TEC values, while IRI-PLUS-TEC values are very close to GPS-TEC values. When GPS-TEC values for both equinoxes are compared, it is seen that TEC values on September equinox are greater than one on March equinox. However, it is observed that GPS-TEC values on June solstice are greater than one on December solstice. Also, the relationship between GPS-TEC values and geomagnetic indexes is investigated.

  4. U.S. Northern Command > Newsroom > Press Releases

    Science.gov Websites

    Skip to main content (Press Enter). Toggle navigation U.S. Northern Command Search Search USNORTHCOM: Search Search USNORTHCOM: Search U.S. Northern Command U.S. Northern Command Home Leadership , 2018 NORAD and USNORTHCOM to host change of command ceremony Nov. 30, 2017 United States, Mexico to

  5. Global variability of mesospheric temperature: Mean temperature field

    NASA Astrophysics Data System (ADS)

    Shepherd, Marianna G.; Evans, Wayne F. J.; Hernandez, G.; Offermann, Dirk; Takahashi, Hisao

    2004-12-01

    Daytime zonally (longitudinally) averaged temperatures from the Wind Imaging Interferometer (WINDII) on the Upper Atmosphere Research Satellite (UARS) and nightly temperatures from various ground-based hydroxyl airglow observations are employed in the study of the global and seasonal variability of the upper mesospheric temperature field. The study examines the latitudinal variability of the annual cycle of mesospheric temperature at 75, 82, and 87 km employing 7 years (1991-1997) of WINDII mesospheric temperature data at latitudes from 20°S to 65°N at 75 km, 35°S to 65°N at 82 km, and from 45°S to 65°N at 87 km height. Particular attention is given to the latitude region of ±40° around the equator. Harmonic analysis of the 7-year temperature time series reveals the presence of a dominant annual, ˜90- and 60-day oscillations at high northern latitudes and a strong semiannual oscillation (SAO) at equatorial and tropical latitudes. A quasi-biennial oscillation (QBO) is also identified extending from 45°S to 65°N. At 75 km the SAO is manifested as minima in the temperature composites at spring and fall equinox and maxima at winter and summer solstice; at 87 km the SAO is out of phase with respect to the 75-km SAO, with maxima at equinox and minima around the solstice periods. The phase reversal takes place around 82 km and is associated with a mesospheric temperature inversion between 77 and 86 km height. Accounting for tidal contribution by adopting tidal predictions by the Extended Canadian Middle Atmosphere Model (CMAM) shows that a strong temperature decrease (˜35 K) seen during the 1993 March equinox at equatorial and tropical latitudes is not associated with solar migrating tides. WINDII global climatology derived at 75, 82, and 87 km revealed mesospheric SAO asymmetry with a stronger September equinox and interhemispheric asymmetry with a quieter and colder southern hemisphere. Comparisons with independent ground-based observations and the Solar

  6. Solar Orientation of Irish Early Christian Oratories

    NASA Astrophysics Data System (ADS)

    Tiede, V. R.

    2001-12-01

    The Hiberno-Latin literary metaphor of "Xpistus sol verus" (Christ the True Sun) finds an architectural analogue in the orientation of the single eastern window of Irish monastic stone chapels or oratories. The author's field surveys in Ireland, Hebrides, Orkney and Shetlands revealed that the window of Irish rectangular dry stone oratories framed the rising solar disk on the Feast Days of selected saints of the Celtic Early Christian Church, AD 800-1100. The most frequent target skyline declinations were to sunrise on the Feast Days of St. Patrick (March 17th) and St. Aidan of Lindisfarne (August 31st). During the Early Christian period, St. Patrick's Day coincided with the Vernal Equinox, and heralded the Paschal Full Moon (i.e., Passover crucifixion) and Easter Sunday as proclaimed by Emperor Constantine at the Council of Nicaea (AD 325). St. Aidan of Lindisfarne (d. AD 651) inspired the Irish monks who, at the Synod of Whitby (AD 664), remained loyal to the Jewish 84-year cycle determining Passover and refused to replace it with the new orthodox 19-year computus for Easter adopted by the Roman Catholic Church (AD 527). Hypothetical affiliation between monastic communities whose oratories share common solar orientation, interior length/width ratios (e.g., 4:3 and 3:2) and units of measurement (e.g., Scottish ell, Coptic cubit, or Roman pes) is discussed. Grateful acknowledgement is made to the Michael D. Coe Fund and Augusta Hazard Fund of Yale University for research grant support in 1999.

  7. Sublimation of icy aggregates in the coma of comet 67P/Churyumov-Gerasimenko detected with the OSIRIS cameras on board Rosetta

    NASA Astrophysics Data System (ADS)

    Gicquel, A.; Vincent, J.-B.; Agarwal, J.; A'Hearn, M. F.; Bertini, I.; Bodewits, D.; Sierks, H.; Lin, Z.-Y.; Barbieri, C.; Lamy, P. L.; Rodrigo, R.; Koschny, D.; Rickman, H.; Keller, H. U.; Barucci, M. A.; Bertaux, J.-L.; Besse, S.; Cremonese, G.; Da Deppo, V.; Davidsson, B.; Debei, S.; Deller, J.; De Cecco, M.; Frattin, E.; El-Maarry, M. R.; Fornasier, S.; Fulle, M.; Groussin, O.; Gutiérrez, P. J.; Gutiérrez-Marquez, P.; Güttler, C.; Höfner, S.; Hofmann, M.; Hu, X.; Hviid, S. F.; Ip, W.-H.; Jorda, L.; Knollenberg, J.; Kovacs, G.; Kramm, J.-R.; Kührt, E.; Küppers, M.; Lara, L. M.; Lazzarin, M.; Moreno, J. J. Lopez; Lowry, S.; Marzari, F.; Masoumzadeh, N.; Massironi, M.; Moreno, F.; Mottola, S.; Naletto, G.; Oklay, N.; Pajola, M.; Pommerol, A.; Preusker, F.; Scholten, F.; Shi, X.; Thomas, N.; Toth, I.; Tubiana, C.

    2016-11-01

    Beginning in 2014 March, the OSIRIS (Optical, Spectroscopic, and Infrared Remote Imaging System) cameras began capturing images of the nucleus and coma (gas and dust) of comet 67P/Churyumov-Gerasimenko using both the wide angle camera (WAC) and the narrow angle camera (NAC). The many observations taken since July of 2014 have been used to study the morphology, location, and temporal variation of the comet's dust jets. We analysed the dust monitoring observations shortly after the southern vernal equinox on 2015 May 30 and 31 with the WAC at the heliocentric distance Rh = 1.53 AU, where it is possible to observe that the jet rotates with the nucleus. We found that the decline of brightness as a function of the distance of the jet is much steeper than the background coma, which is a first indication of sublimation. We adapted a model of sublimation of icy aggregates and studied the effect as a function of the physical properties of the aggregates (composition and size). The major finding of this paper was that through the sublimation of the aggregates of dirty grains (radius a between 5 and 50 μm) we were able to completely reproduce the radial brightness profile of a jet beyond 4 km from the nucleus. To reproduce the data, we needed to inject a number of aggregates between 8.5 × 1013 and 8.5 × 1010 for a = 5 and 50 μm, respectively, or an initial mass of H2O ice around 22 kg.

  8. Temporal Variations of Titan's Middle-Atmospheric Temperatures From 2004-2009 Observed by Cassini/CIRS

    NASA Technical Reports Server (NTRS)

    Achterberg, Richard K.; Gierasch, Peter J.; Flasar, F. Michael; Nixon, Conor A.

    2010-01-01

    We use five and one-half years of limb- and nadir-viewing temperature mapping observations by the Composite Infrared Radiometer-Spectrometer (CIRS) on the Cassini Saturn orbiter, taken between July 2004 and December 2009 (Ls from 293deg to 4deg; northern mid-winter to just after northern spring equinox), to monitor temperature changes in the upper stratosphere and lower mesosphere of Titan. The largest changes are in the northern (winter) polar stratopause, which has declined in temperature by over 20 K between 2005 and 2009. Throughout the rest of the mid to upper stratosphere and lower mesosphere, temperature changes are less than 5 K. In the southern hemisphere, temperatures in the middle stratosphere near 1 mbar increased by 1 to 2K from 2004 through early 2007, then declined by 2 to 4K throughout 2008 and 2009, with the changes, being larger at more, polar latitudes. Middle stratospheric temperatures at mid-northern latitudes show a small 1 to 2K increase, from 2005 through 2009. At north polar latitudes within the polar vortex, temperatures in the middle stratosphe=re show a approx. 4 K increase during 2007, followed by a comparable decrease in temperatures in 2008 and into early 2009. The observed temperature. changes in the north polar region are consistent with a weakening of the subsidence within the descending branch of the middle atmosphere meridional circulation.

  9. Temporal Variations of Titan's Middle-Atmospheric Temperatures from 2004 to 2009 Observed by Cassini/CIRS

    NASA Technical Reports Server (NTRS)

    Achterberg, Richard K.; Gierasch, Peter J.; Conrath, Barney J.; Flasar, F. Michael; Nixon, Conor A.

    2011-01-01

    We use five and one-half years of limb- and nadir-viewing temperature mapping observations by the Composite Infrared Radiometer-Spectrometer (CIRS) on the Cassini Saturn orbiter, taken between July 2004 and December 2009 (Ls from 293 deg. to 48 deg.; northern mid-winter to just after northern spring equinox), to monitor temperature changes in the upper stratosphere and lower mesosphere of Titan. The largest changes are in the northern (winter) polar stratopause, which has declined in temperature by over 20 K between 2005 and 2009. Throughout the rest of the mid to upper stratosphere and lower mesosphere, temperature changes are less than 5 K. In the southern hemisphere, temperatures in the middle stratosphere near 1 mbar increased by 1-2 K from 2004 through early 2007, then declined by 2-4 K throughout 2008 and 2009, with the changes being larger at more polar latitudes. Middle stratospheric temperatures at mid-northern latitudes show a small 1-2 K increase from 2005 through 2009, at north polar latitudes within the polar vortex, temperatures in the middle stratosphere show an approximately 4 K increase during 2007, followed by a comparable decrease in temperatures in 2008 and into early 2009. The observed temperature changes in the north polar region are consistent with a weakening of the subsidence within the descending branch of the middle atmosphere meridional circulation.

  10. Monitoring Mars with the Hubble Space Telescope: 1990-1991 observations

    NASA Technical Reports Server (NTRS)

    James, Philip B.; Clancy, R. Todd; Lee, Steven W.; Martin, Leonard J.; Singer, Robert B.; Smith, ED; Kahn, Ralph A.; Zurek, Richard W.

    1994-01-01

    Images of Mars obtained using the Planetary Camera on the Hubble Space Telescope during 1990 and 1991 are described and analyzed. Multispectral images of Mars record the martian season between L(sub s) = 348 deg and 60 deg corresponding to late winter and spring in the northern hemisphere. The wavelengths of these observations varied between 230 nm in the ultraviolet and 890 nm in the near infrared. We use these images to discuss atmospheric and polar phenomena, to constrain the aerosols and ozone in the martian atmosphere, and to compare surface albedo features within this data set as well as with previous observations. Two methods are used to constrain the opacity of the martian atmosphere: comparisons of ultraviolet images with atmospheric scattering models and examination of contrast changes of surface features observed at visible wavelengths. Our observations are consistent with a Mars which was quite different from the planet when it was viewed by Viking; we estimate an upper limit of 0.1 for equatorial dust opacity near vernal equinox, compared to values of 0.4 to 0.5 measured in Chryse by Viking Lander 1. Later, at L(sub s) = 60 deg, and upper limit of 0.2 was found for dust in the southern hemisphere. Except for suggestions of local dust activity near the north polar cap in late spring, there was no visual evidence of dust storms on the planet. The Hartley band of ozone is within the F230W filter bandpass, and the 230W/336W ratio is therefore sensitive to ozone. High latitude ozone is observed at a concentration similar to that observed by Mariner 9; a seasonal dependence in ozone concentration was observed with concentration decreasing at northern arctic latitudes and increasing at southern midlatitudes as L(sub s) increases from 350 deg to 60 deg. Despite the difference in dust loading, the behavior of condensate clouds and the recession of the north polar cap are consistent with those observed during Viking years. Late winter images of the north polar

  11. FLC expression is down-regulated by cold treatment in Diplotaxis tenuifolia (wild rocket), but flowering time is unaffected.

    PubMed

    Taylor, Jemma L; Massiah, Andrea; Kennedy, Sue; Hong, Yiguo; Jackson, Stephen D

    2017-07-01

    Wild rocket (Diplotaxis tenuifolia) has become a very popular salad leaf due to its peppery taste. It is part of the Brassicaceae family and thus has a high level of homology at the DNA level to other Brassica species including Arabidopsis thaliana. The vernalization and photoperiodic requirements of wild rocket have not been reported to date. Photoperiodic experiments described here demonstrate that rocket is a facultative long day plant. To investigate the vernalization requirement, both seed and young plants were given vernalization treatments at 4°C for different lengths of time. A rocket homologue of FLOWERING LOCUS C (DtFLC) was isolated and shown to functionally complement the Arabidopsis FRI + flc3 null mutant. Whilst the expression of DtFLC was significantly reduced after just one week of cold treatment, cold treatments of two to eight weeks had no significant effect on bolting time of wild rocket indicating that rocket does not have a vernalization requirement. These findings illustrate that important fundamental differences can exist between model and crop plant species, such as in this case where down-regulation of DtFLC expression does not enable earlier flowering in wild rocket as it does in Arabidopsis and many other Brassica species. Copyright © 2017 Elsevier GmbH. All rights reserved.

  12. Confirmation of the Northern Delta Aquariids (NDA, IAU #26) and the Northern June Aquilids (NZC, IAU #164)

    NASA Astrophysics Data System (ADS)

    Holman, David; Jenniskens, Peter

    2012-10-01

    This paper resolves confusion surrounding the Northern delta-Aquariids (NDA, IAU #26). Low-light level video observations with the Cameras for All-sky Meteor Surveillance project in California show distinct showers in the months of July and August. The July shower is identified as the Northern June Aquilids (NZC, IAU #164), while the August shower matches most closely prior data on the Northern delta-Aquariids. This paper validates the existence of both showers, which can now be moved to the list of established showers. The August beta-Piscids (BPI, #342) is not a separate stream, but identical to the Northern delta-Aquariids, and should be discarded from the IAU Working List. We detected the Northern June Aquilids beginning on June 14, through its peak on July 11, and to the shower's end on August 2. The meteors move in a short-period sun grazing comet orbit. Our mean orbital elements are: q = 0.124 ± 0.002 AU, 1/a = 0.512 ± 0.014 AU^{-1}, i = 37°63 ± 0°35, omega = 324°90 ± 0°27, and Omega = 107°93 ± 0°91 (N = 131). This orbit is similar to that of sungrazer comet C/2009 U10.

  13. Geomagnetic Storm Effects at F1 Layer Altitudes in Various Periods of Solar Activity (Irkutsk Station)

    NASA Astrophysics Data System (ADS)

    Kushnarenko, G. P.; Yakovleva, O. E.; Kuznetsova, G. M.

    2018-03-01

    The influence of geomagnetic disturbances on electron density Ne at F1 layer altitudes in different conditions of solar activity during the autumnal and vernal seasons of 2003-2015, according to the data from the Irkutsk digital ionospheric station (52° N, 104° E) is examined. Variations of Ne at heights of 150-190 km during the periods of twenty medium-scale and strong geomagnetic storms have been analyzed. At these specified heights, a vernal-autumn asymmetry of geomagnetic storm effects is discovered in all periods of solar activity of 2003-2015: a considerable Ne decrease at a height of 190 km and a weaker effect at lower levels during the autumnal storms. During vernal storms, no significant Ne decrease as compared with quiet conditions was registered over the entire analyzed interval of 150-190 km.

  14. AmeriFlux CA-Man Manitoba - Northern Old Black Spruce (former BOREAS Northern Study Area)

    DOE Data Explorer

    Amiro, Brian [University of Manitoba

    2016-01-01

    This is the AmeriFlux version of the carbon flux data for the site CA-Man Manitoba - Northern Old Black Spruce (former BOREAS Northern Study Area). Site Description - 55.880° N, 98.481° W, elevation of 259 m, Boreal coniferous: Black spruce; occasional larch present in poorly-drained areas. Groundcover is moss (feathermosses and Sphagnum), Labrador Tea, Vaccinium, and willows are a main component of the understory. It was established in 1993 as a BOREAS site.

  15. 7 CFR 457.143 - Northern potato crop insurance-quality endorsement.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 6 2013-01-01 2013-01-01 false Northern potato crop insurance-quality endorsement... Northern potato crop insurance—quality endorsement. The Northern Potato Crop Insurance Quality Endorsement...) Both FCIC and reinsured policies: Northern Potato Crop Insurance Quality Endorsement 1. Definitions...

  16. 7 CFR 457.143 - Northern potato crop insurance-quality endorsement.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 6 2014-01-01 2014-01-01 false Northern potato crop insurance-quality endorsement... Northern potato crop insurance—quality endorsement. The Northern Potato Crop Insurance Quality Endorsement...) Both FCIC and reinsured policies: Northern Potato Crop Insurance Quality Endorsement 1. Definitions...

  17. 7 CFR 457.143 - Northern potato crop insurance-quality endorsement.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 6 2012-01-01 2012-01-01 false Northern potato crop insurance-quality endorsement... Northern potato crop insurance—quality endorsement. The Northern Potato Crop Insurance Quality Endorsement...) Both FCIC and reinsured policies: Northern Potato Crop Insurance Quality Endorsement 1. Definitions...

  18. 7 CFR 457.143 - Northern potato crop insurance-quality endorsement.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 6 2011-01-01 2011-01-01 false Northern potato crop insurance-quality endorsement... Northern potato crop insurance—quality endorsement. The Northern Potato Crop Insurance Quality Endorsement...) Both FCIC and reinsured policies: Northern Potato Crop Insurance Quality Endorsement 1. Definitions...

  19. Executive Summary: Forests of the Northern United States

    Treesearch

    Stephen R. Shifley; Francisco X. Aguilar; Nianfu Song; Susan I. Stewart; David J. Nowak; Dale D. Gormanson; W. Keith Moser; Sherri Wormstead; Eric J. Greenfield

    2012-01-01

    This executive summary provides an overview of the 200-page report, Forests of the Northern United States, which covers in detail current forest conditions, recent trends, issues, threats and opportunities in the forests in the 20 Northern States. It provides a context for subsequent Northern Forest Futures Project analyses that will forecast alternative future...

  20. Phototaxis of larval and juvenile northern pike

    USGS Publications Warehouse

    Zigler, S.J.; Dewey, M.R.

    1995-01-01

    Age- Phi northern pike Esox lucius prefer vegetated habitats that are difficult to sample with standard towed gears. Light traps can be effective for sampling larval fishes in dense vegetation, given positive phototaxis of fish. We evaluated the phototactic response of young northern pike by comparing the catches of larvae and juveniles obtained with plexiglass traps deployed with a chemical light stick versus traps deployed without a light source (controls) in a laboratory raceway and in a vegetated pond. In the laboratory tests, catches of protolarvae and mesolarvae in lighted traps were 11-35 times greater than catches in control traps. The catches of juvenile northern pike in field and laboratory experiments were 3-15 times greater in lighted traps than in control traps, even though the maximum body width of the larger juveniles was similar to the width of the entrance slots of the traps (5 mm). Larval and juvenile northern pike were photopositive; thus, light traps should effectively sample age-0 northern pike for at least 6 weeks after hatching.

  1. Northern Nutrition.

    ERIC Educational Resources Information Center

    Northwest Territories Dept. of Education, Yellowknife.

    This guide contains nutrition information and nutrition education strategies aimed at residents of the Canadian Arctic. Section I: (1) defines nutrition terms; (2) describes the sources and functions of essential nutrients; (3) explains Canada's food guide and special considerations for the traditional northern Native diet and for lactose…

  2. Sowing pregerminated northern red oak acorns

    Treesearch

    Richard M. Godman; Gilbert A. Mattson

    1992-01-01

    Northern red oak is extremely difficult to regenerate, although it has produced good acorn crops nearly half of the last 32 years in northern Wisconsin. Field trials have shown that for successful seeding, you must protect acorns from predation by wildlife and sow them when temperatures are most favorable for germination.

  3. O3, VOC, NOx, PM2.5 and Meteorological Measurements during an Inversion Episode in Utah's Uinta Basin

    NASA Astrophysics Data System (ADS)

    Moore, K. D.; Martin, R. S.; Hill, S.; Shorthill, H.

    2011-12-01

    Recent measurements found high winter ozone (O3) at several locations in northeastern Utah's Uinta Basin. Similar to Wyoming's Upper Green River Basin, the area has seen recent growth in the gas/oil sector. As a part of a more comprehensive project, a study was conducted examining the relationships between O3, volatile organic compounds (VOCs), nitrogen oxides (NOx), fine particulate matter (PM2.5), and meteorology during an inversion episode. The study took place February 21-25, 2011 at the area's population center (Vernal) and at an area within the gas/oil fields (Red Wash). At both sites, O3 and NOx, displayed expected diurnal behaviors. The 1-hr O3 concentrations ranged from 10-90 ppb at Vernal and 34-107 ppb at Red Wash. Average diurnal O3 maximums (±95% CI) were 70.4±12.1 ppb and 76.8±12.6 ppb at Vernal and Red Wash, respectively. The Red Wash average O3 diurnal curve was broader than that at Vernal and did not titrate out as rapidly in the evening and morning hours. In contrast, higher NOx was observed at Vernal, with hourly averaged values ranging from 4.5-80.2 ppb, compared to 1.5-29.7 ppb at Red Wash. The NOx tended to follow traffic patterns at both sites, with morning maximum 1-hr averages of 40.8±12.1 ppb and 20.2±8.7 ppb, respectively. A portable O3 monitor attached to a tethered balloon found high ground level O3 (70-80 ppb) and a decrease to relatively constant levels (50-60 ppb) by 150 m agl. Methane and non-methane hydrocarbons (NHMC) were collected at least twice per day using whole vial and sorbent cartridges, followed by GC-FID and GC-MS analysis. The gas/oil field samples (Red Wash) found significantly higher CH4 levels (2.71±0.32 ppm) compared to the Vernal samples (1.82±0.14 ppm). The NMHC were likewise higher at the Red Wash location. Calculation of the maximum incremental reactivity (MIR) estimated that methane, ethane, propane, acetylene, remaining alkanes, alkenes, and aromatics accounted for 7.9%, 18.5%, 4.7%, 1.0%, 20.6%, 46

  4. Success of Underplanting Northern Red Oaks

    Treesearch

    Martin A. Spetich; Daniel C. Dey; Paul S. Johnson; David L. Graney

    2004-01-01

    We summarize results of the growth and survival of northern red oak (Quercus rubra L.) seedlings 11 years after planting in shelterwoods in the Boston Mountains of Arkansas. Shelterwood overstories were harvested 3 years after underplanting > 4,000 northern red oak seedlings. Woody vegetation that was competing with planted seedlings received two...

  5. Northern Australia

    Atmospheric Science Data Center

    2013-04-16

    article title:  Tropical Northern Australia   ... view. Water appears in blue shades in the right image, for example, because glitter makes the water look brighter at the aft camera's view ... MD. The MISR data were obtained from the NASA Langley Research Center Atmospheric Science Data Center in Hampton, VA. Image ...

  6. A statistical study of single crest phenomenon in the equatorial ionospheric anomaly region using Swarm A satellite

    NASA Astrophysics Data System (ADS)

    Fathy, Adel; Ghamry, Essam

    2017-03-01

    Though the Equatorial Ionospheric Anomaly (EIA) is represented by two crests within ±15° latitude, a single crest is also observed in the entire ionosphere. Few studies have addressed single crest phenomena. A statistical study of 2237 single crest phenomenon from the in situ electron density measurements of Swarm A satellite was investigated during December 2013-December 2015. Our analysis focused on local time, seasonal, and both geographic and geomagnetic latitudinal variations. Our results show the following observations: 1 - The maximum number of events peaks mainly in the dayside region around 0800-1200 LT and these occur mainly within the magnetic equator. 2 - The maximum amplitude of the single crests take place most prominently during equinoxes. 3 - The majority of single crests occur in the northern hemisphere. 4 - The seasonal distribution of the events shows that the summer events are located further from the magnetic equator in the northern hemisphere and shift their locations into the southern hemisphere in winter, while spring events are centered along the magnetic equator. 5 - Dayside single crest events appear close to the magnetic equator and more centered on the equator in winter season. 6 - Dawn, night and dusk side events reverse their location from northern hemisphere in summer to southern hemisphere in winter.

  7. Insights into the Drought and Heat Avoidance Mechanism in Summer-Dormant Mediterranean Tall Fescue

    PubMed Central

    Missaoui, Ali M.; Malinowski, Dariusz P.; Pinchak, William E.; Kigel, Jaime

    2017-01-01

    Summer dormancy is an evolutionary response that some perennial cool-season grasses adopted as an avoidance strategy to escape summer drought and heat. It is correlated with superior survival after severe summer droughts in many perennial grass species originating from Mediterranean environments. Understanding the genetic mechanism and environmental determinants of summer dormancy is important for interpreting the evolutionary history of seasonal dormancy and for the development of genomic tools to improve the efficiency of genetic selection for this important trait. The objectives of this research are to assess morphological and biochemical attributes that seem to be specific for the characterization of summer dormancy in tall fescue, and to validate the hypothesis that genes underlying stem determinacy might be involved in the mechanism of summer dormancy. Our results suggest that vernalization is an important requirement in the onset of summer dormancy in tall fescue. Non-vernalized tall fescue plants do not exhibit summer dormancy as vernalized plants do and behave more like summer-active types. This is manifested by continuation of shoot growth and high root activity in water uptake during summer months. Therefore, summer dormancy in tall fescue should be tested only in plants that underwent vernalization and are not subjected to water deficit during summer months. Total phenolic concentration in tiller bases (antioxidants) does not seem to be related to vernalization. It is most likely an environmental response to protect meristems from oxidative stress. Sequence analysis of the TFL1 homolog CEN gene from tall fescue genotypes belonging to summer-dormant and summer-active tall fescue types showed a unique deletion of three nucleotides specific to the dormant genotypes. Higher tiller bud numbers in dormant plants that were not allowed to flower and complete the reproductive cycle, confirmed that stem determinacy is a major component in the mechanism of summer

  8. Insights into the Drought and Heat Avoidance Mechanism in Summer-Dormant Mediterranean Tall Fescue.

    PubMed

    Missaoui, Ali M; Malinowski, Dariusz P; Pinchak, William E; Kigel, Jaime

    2017-01-01

    Summer dormancy is an evolutionary response that some perennial cool-season grasses adopted as an avoidance strategy to escape summer drought and heat. It is correlated with superior survival after severe summer droughts in many perennial grass species originating from Mediterranean environments. Understanding the genetic mechanism and environmental determinants of summer dormancy is important for interpreting the evolutionary history of seasonal dormancy and for the development of genomic tools to improve the efficiency of genetic selection for this important trait. The objectives of this research are to assess morphological and biochemical attributes that seem to be specific for the characterization of summer dormancy in tall fescue, and to validate the hypothesis that genes underlying stem determinacy might be involved in the mechanism of summer dormancy. Our results suggest that vernalization is an important requirement in the onset of summer dormancy in tall fescue. Non-vernalized tall fescue plants do not exhibit summer dormancy as vernalized plants do and behave more like summer-active types. This is manifested by continuation of shoot growth and high root activity in water uptake during summer months. Therefore, summer dormancy in tall fescue should be tested only in plants that underwent vernalization and are not subjected to water deficit during summer months. Total phenolic concentration in tiller bases (antioxidants) does not seem to be related to vernalization. It is most likely an environmental response to protect meristems from oxidative stress. Sequence analysis of the TFL1 homolog CEN gene from tall fescue genotypes belonging to summer-dormant and summer-active tall fescue types showed a unique deletion of three nucleotides specific to the dormant genotypes. Higher tiller bud numbers in dormant plants that were not allowed to flower and complete the reproductive cycle, confirmed that stem determinacy is a major component in the mechanism of summer

  9. Adaptation of barley to mild winters: A role for PPDH2

    PubMed Central

    2011-01-01

    Background Understanding the adaptation of cereals to environmental conditions is one of the key areas in which plant science can contribute to tackling challenges presented by climate change. Temperature and day length are the main environmental regulators of flowering and drivers of adaptation in temperate cereals. The major genes that control flowering time in barley in response to environmental cues are VRNH1, VRNH2, VRNH3, PPDH1, and PPDH2 (candidate gene HvFT3). These genes from the vernalization and photoperiod pathways show complex interactions to promote flowering that are still not understood fully. In particular, PPDH2 function is assumed to be limited to the ability of a short photoperiod to promote flowering. Evidence from the fields of biodiversity, ecogeography, agronomy, and molecular genetics was combined to obtain a more complete overview of the potential role of PPDH2 in environmental adaptation in barley. Results The dominant PPDH2 allele is represented widely in spring barley cultivars but is found only occasionally in modern winter cultivars that have strong vernalization requirements. However, old landraces from the Iberian Peninsula, which also have a vernalization requirement, possess this allele at a much higher frequency than modern winter barley cultivars. Under field conditions in which the vernalization requirement of winter cultivars is not satisfied, the dominant PPDH2 allele promotes flowering, even under increasing photoperiods above 12 h. This hypothesis was supported by expression analysis of vernalization-responsive genotypes. When the dominant allele of PPDH2 was expressed, this was associated with enhanced levels of VRNH1 and VRNH3 expression. Expression of these two genes is needed for the induction of flowering. Therefore, both in the field and under controlled conditions, PPDH2 has an effect of promotion of flowering. Conclusions The dominant, ancestral, allele of PPDH2 is prevalent in southern European barley germplasm

  10. Holocene climate and climate variability of the northern Gulf of Mexico and adjacent northern Gulf Coast: A review

    USGS Publications Warehouse

    Poore, Richard Z.

    2008-01-01

    Marine records from the northern Gulf of Mexico indicate that significant multidecadal- and century-scale variability was common during the Holocene. Mean annual sea-surface temperature (SST) during the last 1,400 years may have varied by 3°C, and excursions to cold SST coincide with reductions in solar output. Broad trends in Holocene terrestrial climate and environmental change along the eastern portion of the northern Gulf Coast are evident from existing pollen records, but the high-frequency details of climate variability are not well known. Continuous and well-dated records of climate change and climate variability in the western portion of the northern Gulf Coast are essentially lacking.Information on Holocene floods, droughts, and storm frequency along the northern Gulf Coast is limited. Records of floods may be preserved in continental shelf sediments, but establishing continuity and chronologies for sedimentary sequences on the shelf presents challenges due to sediment remobilization and redeposition during storms. Studies of past storm deposits in coastal lakes and marshes show promise for constructing records of past storm frequency. A recent summary of sea-level history of the northern Gulf Coast indicates sea level was higher than modern sea level several times during the last few thousand years.

  11. 27 CFR 9.70 - Northern Sonoma.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2011-04-01 2011-04-01 false Northern Sonoma. 9.70 Section 9.70 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.70 Northern Sonoma. (a) Name. The name of the...

  12. 27 CFR 9.70 - Northern Sonoma.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2012-04-01 2012-04-01 false Northern Sonoma. 9.70 Section 9.70 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.70 Northern Sonoma. (a) Name. The name of the...

  13. 27 CFR 9.70 - Northern Sonoma.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2013-04-01 2013-04-01 false Northern Sonoma. 9.70 Section 9.70 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY ALCOHOL AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.70 Northern Sonoma. (a) Name. The name of the...

  14. 27 CFR 9.70 - Northern Sonoma.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Northern Sonoma. 9.70 Section 9.70 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.70 Northern Sonoma. (a) Name. The name of the...

  15. 27 CFR 9.70 - Northern Sonoma.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2014-04-01 2014-04-01 false Northern Sonoma. 9.70 Section 9.70 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY ALCOHOL AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.70 Northern Sonoma. (a) Name. The name of the...

  16. Base of fresh ground water, northern Louisiana Salt-Dome Basin and vicinity, northern Louisiana and southern Arkansas

    USGS Publications Warehouse

    Ryals, G.N.

    1980-01-01

    The National Waste Terminal Storage Program is an effort by the U.S. Department of Energy to locate and develop sites for disposal or storage of commercially produced radioactive wastes. As part of this program, salt domes in the northern Louisiana salt-dome basin are being studied to determine their suitability as repositories. Part of the U.S. Geological Survey 's participation in the program has been to describe the regional geohydrology of the northern Louisiana salt-dome basin. A map based on a compilation of published data and the interpretation of electrical logs shows the altitude of the base of freshwater in aquifers in the northern Louisiana salt-dome basin. (USGS)

  17. U.S. Northern Command > Newsroom > Fact Sheets

    Science.gov Websites

    Operations Command, North U.S. Marine Forces Northern Command U.S. Fleet Forces Command Air Forces Northern U.S. Army North Joint Task Force North Joint Task Force Civil Support Joint Task Force Alaska Joint

  18. Imaging Lithospheric-scale Structure Beneath Northern Altiplano in Southern Peru and Northern Bolivia

    NASA Astrophysics Data System (ADS)

    Kumar, A.; Wagner, L. S.; Beck, S. L.; Zandt, G.; Long, M. D.

    2014-12-01

    The northern Altiplano plateau of southern Peru and northern Bolivia is one of the highest topographic features on the Earth, flanked by Western and Eastern Cordillera along its margin. It has strongly influenced the local and far field lithospheric deformation since the early Miocene (Masek et al., 1994). Previous studies have emphasized the importance of both the crust and upper mantle in the evolution of Altiplano plateau (McQuarrie et al., 2005). Early tomographic and receiver function studies, south of 16° S, show significant variations in the crust and upper mantle properties in both perpendicular and along strike direction of the Altiplano plateau (Dorbath et. al., 1993; Myers et al., 1998; Beck and Zandt, 2002). In order to investigate the nature of subsurface lithospheric structure below the northern Altiplano, between 15-18° S, we have determined three-dimensional seismic tomography models for Vp and Vs using P and S-wave travel time data from two recently deployed local seismic networks of CAUGHT and PULSE. We also used data from 8 stations from the PERUSE network (PERU Subduction Experiment). Our preliminary tomographic models show a complex variation in the upper mantle velocity structure with depth, northwest and southeast of lake Titicaca. We see the following trend, at ~85 km depth, northwest of lake Titicaca: low Vp and Vs beneath the Western Cordillera, high Vs beneath the Altiplano and low Vp and Vs beneath the Eastern Cordillera. This low velocity anomaly, beneath Eastern Cordillera, seems to coincide with Kimsachata, a Holocene volcano in southern Peru. At depth greater than ~85 km: we find high velocity anomaly beneath the Western Cordillera and low Vs beneath the Altiplano. This high velocity anomaly, beneath Western Cordillera, coincides with the well-located Wadati-Benioff zone seismicity and perhaps represents the subducting Nazca slab. On the southeast of lake Titicaca, in northern Bolivia, we see a consistently high velocity anomaly

  19. 7 CFR 457.146 - Northern potato crop insurance-storage coverage endorsement.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 6 2014-01-01 2014-01-01 false Northern potato crop insurance-storage coverage... Northern potato crop insurance—storage coverage endorsement. The Northern Potato Crop Insurance Storage... for insurance provider) Both FCIC and reinsured policies: Northern Potato Crop Insurance Storage...

  20. 7 CFR 457.146 - Northern potato crop insurance-storage coverage endorsement.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 6 2012-01-01 2012-01-01 false Northern potato crop insurance-storage coverage... Northern potato crop insurance—storage coverage endorsement. The Northern Potato Crop Insurance Storage... for insurance provider) Both FCIC and reinsured policies: Northern Potato Crop Insurance Storage...

  1. 7 CFR 457.146 - Northern potato crop insurance-storage coverage endorsement.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 6 2011-01-01 2011-01-01 false Northern potato crop insurance-storage coverage... Northern potato crop insurance—storage coverage endorsement. The Northern Potato Crop Insurance Storage... for insurance provider) Both FCIC and reinsured policies: Northern Potato Crop Insurance Storage...

  2. 7 CFR 457.146 - Northern potato crop insurance-storage coverage endorsement.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 6 2013-01-01 2013-01-01 false Northern potato crop insurance-storage coverage... Northern potato crop insurance—storage coverage endorsement. The Northern Potato Crop Insurance Storage... for insurance provider) Both FCIC and reinsured policies: Northern Potato Crop Insurance Storage...

  3. From the Northern Eurasia Earth Science Partnership Initiative (NEESPI) towards the Northern Eurasia Future Initiative (NEFI)

    NASA Astrophysics Data System (ADS)

    Groisman, Pavel; Gutman, Garik; Gulev, Sergey; Maksyutov, Shamil

    2015-04-01

    Northern Eurasia Earth Science Partnership Initiative (NEESPI, http://neespi.org) was launched in 2004. With its multidisciplinary focus, the internationally funded NEESPI (more than 170 individual international projects during the past decade) has challenged participants to research climate-ecosystem interactions, societal impacts from extreme events in Northern Eurasia, and the feedbacks of these interactions and impacts to the global Earth system. NEESPI was endorsed by major ESSP Programs and Projects and the cornerstone support for the NEESPI studies was provided by the NASA Land Cover and Land Use Change Program and the Russian Academy of Sciences. Now it is the time to synthesis the main achievements of the NEESPI researchers and to re-assess its Science Questions and Objectives of the regional research within the new Future Earth Program paradigm with the focus on interdisciplinary solution-oriented approach that will allow effective policy-making in environment management and control. At the sequence of Workshops (the last of them will be in Prague one week prior to this Assembly) we formulated a major Science Question of the new Northern Eurasia Future Initiative (NEFI): "What will the changes in the regional ecosystems dynamics and interactions mean for the societal well-being, activities, health, and strategic planning in Northern Eurasia?" The major NEFI challenge will be the services aimed on providing in Northern Eurasia a sustainable societal development in changing climate, ecosystems, and societies. At this presentation we shall brief the audience about the main results of the NEESPI researchers, and lay down the plans for the future NEFI studies. At the side event of the Meeting, we shall initiate preparation of the book which will synthesize major NEESPI achievements.

  4. Predation on Northern krill (Meganyctiphanes norvegica Sars).

    PubMed

    Simard, Yvan; Harvey, Michel

    2010-01-01

    We consider predation as a function of prey concentration with a focus on how this interaction is influenced by biological-physical interactions, and wider oceanographic processes. In particular, we examine how the anti-predation behaviour of Northern krill interacts with ocean-circulation process to influence its vulnerability to predation. We describe how three-dimensional (3D) circulation interacts with in situ light levels to modulate predator-prey interactions from small to large scales, and illustrate how the stability of the predator-prey system is sometimes perturbed as a consequence. Northern krill predators include a wide range of species from the pelagic and benthic strata, as well as birds. Many exhibit adaptations in their feeding strategy to take advantage of the dynamic physical-biological processes that determine the distribution, concentration and vulnerability of Northern krill. Among them, baleen whales appear to have developed particularly efficient predation strategies. A literature search indicates that Northern krill are a major contributor to ecosystem function throughout its distributional range, and a key species with respect to the flow of energy to upper trophic levels. A list of future research needed to fill gaps in our understanding of Northern krill predator-prey interaction is provided. Copyright © 2010 Elsevier Ltd. All rights reserved.

  5. Survival and growth of northern white-cedar and balsam fir seedlings in riparian management zones in northern Minnesota, USA

    Treesearch

    Brian J. Palik; Brooke K. Haworth; Andrew J. David; Randall K. Kolka

    2015-01-01

    Northern white-cedar (Thuja occidentalis) and balsam fir (Abies balsamea.) are co-occurring species in riparian forests of the western Great Lakes region. Throughout much of the region, northern white-cedar has been experiencing population declines due to herbivory by white-tailed deer (Odocoileus virginianus)....

  6. Seasonal/Latitudinal Models of Stratospheric Photochemistry on Saturn

    NASA Astrophysics Data System (ADS)

    Moses, J. I.; Greathouse, T. K.

    2004-11-01

    To date, most investigations of stratospheric photochemistry on the outer planets have involved one-dimensional (1-D) ``global-average'' or single-latitude models for a single season. With Cassini CIRS poised to map hydrocarbon distributions across Saturn, and with advances in detector technology and telescope size for Earth-based observations allowing composition and temperatures to be derived as a function of latitude, we are now in a position to evaluate the effectiveness of 1-D models in describing the stratospheric composition. Are 2-D models that include meridional transport necessary to reproduce the observed hydrocarbon latitudinal distributions, or can 1-D seasonal models provide an accurate description? In order to evaluate these questions, we have developed a realistic, time-variable, 1-D seasonal model for stratospheric photochemistry on Saturn. The model accounts for variations in orbital position and in ultraviolet flux due to solar-cycle variations and ring-shadow effects. The results for one Saturnian year, starting at Ls = 0o in 1980 and running until the next vernal equinox in 2009, are presented for numerous latitudes. Due to the long vertical diffusion time scale at pressures greater than ˜1 mbar, we find that seasonal effects are more pronounced at high altitudes. In addition, a phase lag between insolation and chemical response increases with increasing pressure. In the summer hemisphere, hydrocarbon abundances do not exhibit much variation with latitude because the increase in the length of the day with increasing latitude counterbalances the increasing solar zenith angle, causing the daily-averaged insolation to remain nearly constant over a wide range of latitudes. Latitudinal variations are more pronounced during other seasons. We compare our model results with various observations.

  7. Evidence for an east-west regional gravity trend in northern Tunisia: Insight into the structural evolution of northern Tunisian Atlas

    NASA Astrophysics Data System (ADS)

    Jallouli, Chokri; Mogren, Saad; Mickus, Kevin; Turki, Mohamed Moncef

    2013-11-01

    The Atlas orogeny in northern Algeria and Tunisia led to the destruction of Tethys oceanic lithosphere and cumulated in a collision of microplates rifted off the European margin with the North African continental margin. The location of the boundary between African plate and Kabylian microplate is expressed in northern Algeria by a crustal wedge with double vergence of thrust sheets, whereas in northern Tunisia the geologic environment is more complex and the location of the plate boundary is ambiguous. In this study, we analyzed gravity data to constrain the crustal structure along the northern margin of Tunisia. The analysis includes a separation of regional and residual gravity anomalies and the application of gradient operators to locate density contrast boundaries. The horizontal gradient magnitude and directional gradient highlight a prominent regional E-W gravity gradient in the northern Tunisian Atlas interpreted as a deep fault (active since at least the Early Mesozoic) having a variable kinematic activity depending on the tectonic regime in the region. The main E-W gravity gradient separates two blocks having different gravitational and seismic responses. The southern block has numerous gravity lineaments trending in different directions implying several density variations within the crust, whereas the northern block shows a long-wavelength negative gravity anomaly with a few lineaments. Taking into account the geologic context of the Western Mediterranean region, we consider the E-W prominent feature as the boundary between African plate and Kabylian microplate in northern Tunisia that rifted off Europe. This hypothesis fits most previous geological and geophysical studies and has an important impact on the petroleum and mineral resource prospection as these two blocks were separated by an ocean and they did not belong to the same margin.

  8. Dermatophytosis in northern Africa.

    PubMed

    Nweze, E I; Eke, I

    2016-03-01

    Infections caused by dermatophytes are a global problem and a major public health burden in the world today. In Africa, especially in the northern geographical zone, dermatophytic infections are being reported at an alarming rate. This is mostly because of some local but unique cultural practices, socioeconomic and environmental conditions, lack of reliable diagnostic personnel and facilities and ineffective treatment. Interestingly, the pathogen spectrum and the clinical manifestation are most times different from what is seen in other continents. Several epidemiological studies have been performed on the incidence and aetiology of dermatophytoses in northern Africa. However, there is currently no review article with up-to-date information on the relevant findings reported so far in this region. This information is necessary for clinicians who treat dermatophytic infections all over the world since agents of dermatophytes are no longer restricted because of the rapid mobility of humans from one part of the world to another. Moreover, the epidemiology of dermatophytoses is known to change over time, thus requiring the update of information from time to time. A review of relevant studies published on dermatophytoses in northern Africa is presented. This covers all of old Sudan, Algeria, Egypt, Libya, Tunisia and Morocco. © 2015 Blackwell Verlag GmbH.

  9. A case for ancient springs in Arabia Terra, Mars.

    PubMed

    Allen, Carlton C; Oehler, Dorothy Z

    2008-12-01

    Based on new image data from the High Resolution Imaging Science Experiment (HiRISE) on Mars Reconnaissance Orbiter (MRO), a case can be made that several structures in Vernal Crater, Arabia Terra are ancient springs. This interpretation is based on comprehensive geomorphologic analysis coupled with assessment of multiple hypotheses. The structures identified extend across several kilometers and are exceptional in that nothing with their detail and scale has been reported from Mars. The deposits are associated with an extensive fracture system that may have facilitated upward flow of warm fluids. Several additional spring-like features occur in Vernal Crater, and it is possible that these are part of a major province of spring activity. Since springs are environments where life could have evolved on Mars, where that life could have found refuge as the climate became colder and drier, and where signatures of that life may be preserved, Vernal Crater may be a site of major astrobiological importance.

  10. Harvesting systems for the northern forest hardwoods

    Treesearch

    Chris B. LeDoux

    2011-01-01

    This monograph is a summary of research results and environmental compliance measures for timber harvesting operations. Data are presented from the Northern Research Station's forest inventory and analysis of 20 states in the northern forest hardwoods. Harvesting systems available in the region today are summarized. Equations for estimating harvesting costs are...

  11. The Distant Sodium Tail of Mercury

    NASA Technical Reports Server (NTRS)

    Potter, A. E.; Killen, R. M.; Morgan, T. H.

    2001-01-01

    Models of the sodium atmosphere of Mercury predict the possible existence of a cornet-like sodium tail. Detection and mapping of the predicted sodium tail would provide quantitative data on the energy of the process that produces sodium atoms from the planetary surface. Previous efforts to detect the sodium tail by means of observations done during daylight hours have been only partially successful because scattered sunlight obscured the weak sodium emissions in the tail. However, at greatest eastern elongation around the March equinox in the northern hemisphere, Mercury can be seen as an evening star in astronomical twilight. At this time, the intensity of scattered sunlight is low enough that sodium emissions as low as 500 Rayleighs can be detected. Additional information is contained in the original extended abstract.

  12. The Alcoholism Situation in a Northern City

    ERIC Educational Resources Information Center

    Martynov, M. Iu.; Martynova, D. Iu.

    2012-01-01

    Alcohol abuse in Russia has been increasing in recent years, especially in northern regions, as has the incidence of alcohol-related disease rates. A survey was conducted in Surgut (the Khanty-Mansi autonomous okrug) that determined the factors lending to the prevalence of alcohol abuse among the population of the northern city and assessed the…

  13. Ecohydrology of seepage springs in an urban National Park

    NASA Astrophysics Data System (ADS)

    Knee, K.; Melone, J.; Friedel, B.; Fong, D.

    2014-12-01

    Shallow groundwater-fed seepage springs, also known as hypotelminorheic habitats, are found around the Washington, DC area, including in the George Washington Parkway, a National Park unit in northern Virginia. These springs differ from better-known vernal pools both in their hydrology and their ecology: because they are groundwater-fed, they are more resistant to drying out than vernal pools, and they harbor cave-adapted arthropod species including amphipods of the genus Stygobroumus. This project seeks to understand the ecohydrology of the hypotelminorheic habitats that support these species, some of which are endangered, and which comprise an important but underappreciated component of biodiversity in DC-area National Parks. Our study focuses on two hypotelminorheic habitats in the GW Parkway area and consists of three main components: (1) a weekly population census of Stygobroumus using multiple mark-recapture methodology, (2) weekly monitoring of dissolved radon, a tracer of groundwater discharge, as well as conductivity, dissolved oxygen, and pH, and (3) continuous logging of spring water temperature. This poster presents preliminary data from the Stygobroumus population census and explores how these animals may be affected by spring hydrology. Specifically, we use temperature, conductivity, radon activity and precipitation data from a nearby weather station to understand how the springs respond to episodic and seasonal variation in temperature, precipitation and groundwater seepage and how this affects Stygobromus populations. We also explore whether variations in Stygobromus counts reflect (1) active migration between the surficial spring and the larger subterranean habitat, or (2) passive flushing driven by groundwater discharge. Our results provide basic hydrologic data about a little-understood habitat type and will help managers protect Stygobromus in the urban park environment.

  14. Seasonal prevailing surface winds in Northern Serbia

    NASA Astrophysics Data System (ADS)

    Tošić, Ivana; Gavrilov, Milivoj B.; Marković, Slobodan B.; Ruman, Albert; Putniković, Suzana

    2018-02-01

    Seasonal prevailing surface winds are analyzed in the territory of Northern Serbia, using observational data from 12 meteorological stations over several decades. In accordance with the general definition of prevailing wind, two special definitions of this term are used. The seasonal wind roses in 16 directions at each station are analyzed. This study shows that the prevailing winds in Northern Serbia have northwestern and southeastern directions. Circulation weather types over Serbia are presented in order to determine the connections between the synoptic circulations and prevailing surface winds. Three controlling pressure centers, i.e., the Mediterranean cyclone, Siberian high, and the Azores anticyclone, appear as the most important large-scale factors that influence the creation of the prevailing winds over Northern Serbia. Beside the synoptic cause of the prevailing winds, it is noted that the orography of the eastern Balkans has a major influence on the winds from the second quadrant. It was found that the frequencies of circulation weather types are in agreement with those of the prevailing winds over Northern Serbia.

  15. Seasonally asymmetric enhancement of northern vegetation productivity

    NASA Astrophysics Data System (ADS)

    Park, T.; Myneni, R.

    2017-12-01

    Multiple evidences of widespread greening and increasing terrestrial carbon uptake have been documented. In particular, enhanced gross productivity of northern vegetation has been a critical role leading to observed carbon uptake trend. However, seasonal photosynthetic activity and its contribution to observed annual carbon uptake trend and interannual variability are not well understood. Here, we introduce a multiple-source of datasets including ground, atmospheric and satellite observations, and multiple process-based global vegetation models to understand how seasonal variation of land surface vegetation controls a large-scale carbon exchange. Our analysis clearly shows a seasonally asymmetric enhancement of northern vegetation productivity in growing season during last decades. Particularly, increasing gross productivity in late spring and early summer is obvious and dominant driver explaining observed trend and variability. We observe more asymmetric productivity enhancement in warmer region and this spatially varying asymmetricity in northern vegetation are likely explained by canopy development rate, thermal and light availability. These results imply that continued warming may facilitate amplifying asymmetric vegetation activity and cause these trends to become more pervasive, in turn warming induced regime shift in northern land.

  16. Accessing northern California earthquake data via Internet

    NASA Astrophysics Data System (ADS)

    Romanowicz, Barbara; Neuhauser, Douglas; Bogaert, Barbara; Oppenheimer, David

    The Northern California Earthquake Data Center (NCEDC) provides easy access to central and northern California digital earthquake data. It is located at the University of California, Berkeley, and is operated jointly with the U.S. Geological Survey (USGS) in Menlo Park, Calif., and funded by the University of California and the National Earthquake Hazard Reduction Program. It has been accessible to users in the scientific community through Internet since mid-1992.The data center provides an on-line archive for parametric and waveform data from two regional networks: the Northern California Seismic Network (NCSN) operated by the USGS and the Berkeley Digital Seismic Network (BDSN) operated by the Seismographic Station at the University of California, Berkeley.

  17. Northern Exports of softwood products, 1980-85

    Treesearch

    James E. Granskog

    1988-01-01

    Assessment of export opportunities for softwood products from the North has been hampered by a lack of information describing foreign sales from the region. This article describes the value and volume of softwood products exported from the northern United States for 1980 through 1985. Roundwood productsmostly spruce logs from Maine and Vermont- are the largest northern...

  18. Logging truck noise near nesting northern goshawks

    Treesearch

    Teryl G. Grubb; Larry L. Pater; David K. Delaney

    1998-01-01

    We measured noise levels of four logging trucks as the trucks passed within approximately 500 m of two active northern goshawk (Accipiter gentilis) nests on the Kaibab Plateau in northern Arizona in 1997. Neither a brooding adult female nor a lone juvenile exhibited any discernable behavioral response to logging truck noise, which peaked at 53.4 and...

  19. Northern Parkway PTA Makes Health a Habit

    ERIC Educational Resources Information Center

    Ferdinand, Marilyn

    2011-01-01

    Health and fitness have been on the agenda of Northern Parkway Elementary School for quite some time, thanks to the concerted efforts of its involved and active PTA officers and members. For the past five years, the Northern Parkway PTA has held a popular and well-attended Family Fun and Fitness Night and has complemented the activities and…

  20. Soil organic carbon pools in the northern circumpolar permafrost region

    Treesearch

    C. Tarnocai; J.G. Canadell; E.A.G. Schuur; P. Kuhry; G. Mazhitova; S. Zimov

    2009-01-01

    The Northern Circumpolar Soil Carbon Database was developed to determine carbon pools in soils of the northern circumpolar permafrost region. Here we report a new estimate of the carbon pools in soils of the northern permafrost region, including deeper layers and pools not accounted for in previous analyses.

  1. Adapting online learning for Canada's Northern public health workforce.

    PubMed

    Bell, Marnie; MacDougall, Karen

    2013-01-01

    Canada's North is a diverse, sparsely populated land, where inequalities and public health issues are evident, particularly for Aboriginal people. The Northern public health workforce is a unique mix of professional and paraprofessional workers. Few have formal public health education. From 2009 to 2012, the Public Health Agency of Canada (PHAC) collaborated with a Northern Advisory Group to develop and implement a strategy to strengthen public health capacity in Canada's 3 northern territories. Access to relevant, effective continuing education was identified as a key issue. Challenges include diverse educational and cultural backgrounds of public health workers, geographical isolation and variable technological infrastructure across the north. PHAC's Skills Online program offers Internet-based continuing education modules for public health professionals. In partnership with the Northern Advisory Group, PHAC conducted 3 pilots between 2008 and 2012 to assess the appropriateness of the Skills Online program for Northern/Aboriginal public health workers. Module content and delivery modalities were adapted for the pilots. Adaptations included adding Inuit and Northern public health examples and using video and teleconference discussions to augment the online self-study component. Findings from the pilots were informative and similar to those from previous Skills Online pilots with learners in developing countries. Online learning is effective in bridging the geographical barriers in remote locations. Incorporating content on Northern and Aboriginal health issues facilitates engagement in learning. Employer support facilitates the recruitment and retention of learners in an online program. Facilitator assets included experience as a public health professional from the north, and flexibility to use modified approaches to support and measure knowledge acquisition and application, especially for First Nations, Inuit and Metis learners. Results demonstrate that

  2. The role of cold cues at different life stages on germination and flowering phenology.

    PubMed

    Rubin, Matthew J; Friedman, Jannice

    2018-04-23

    The timing of major phenological transitions is critical to lifetime fitness, and life history theory predicts differences for annual and perennial plants. To correctly time these transitions, many plants rely on environmental cues such as exposure to extended periods of cold, which may occur at different stages throughout their lifetime. We studied the role of cold at different life stages, by jointly exposing seed (stratification) and rosettes (vernalization) to cold. We used 23 populations of Mimulus guttatus, which vary from annuals to perennials, and investigated how cold at one or both stages affected germination, flowering, growth, and biomass. We found that stratification and vernalization interact to affect life cycle transitions, and that cold at either stage could synchronize flowering phenology. For perennials, either stratification or vernalization is necessary for maximum flowering. We also found that germination timing covaried with later traits. Moreover, plants from environments with dissimilar climates displayed different phenological responses to stratification or vernalization. In general, cold is more important for seed germination in annuals and plants from environments with warm temperatures and variable precipitation. In contrast, cold is more important for flowering in perennials: it accelerates flowering in plants from lower precipitation environments, and it increases flowering proportion in plants from cooler, more stable precipitation environments. We discuss our findings in the context of the variable environments plants experience within a population and the variation encountered across the biogeographic native range of the species. © 2018 Botanical Society of America.

  3. Geologic map of the northern plains of Mars

    USGS Publications Warehouse

    Tanaka, Kenneth L.; Skinner, James A.; Hare, Trent M.

    2005-01-01

    The northern plains of Mars cover nearly a third of the planet and constitute the planet's broadest region of lowlands. Apparently formed early in Mars' history, the northern lowlands served as a repository both for sediments shed from the adjacent ancient highlands and for volcanic flows and deposits from sources within and near the lowlands. Geomorphic evidence for extensive tectonic deformation and reworking of surface materials through release of volatiles occurs throughout the northern plains. In the polar region, Planum Boreum contains evidence for the accumulation of ice and dust, and surrounding dune fields suggest widespread aeolian transport and erosion. The most recent regional- and global-scale maps describing the geology of the northern plains are largely based on Viking Orbiter image data (Dial, 1984; Witbeck and Underwood, 1984; Scott and Tanaka, 1986; Greeley and Guest, 1987; Tanaka and Scott, 1987; Tanaka and others, 1992a; Rotto and Tanaka, 1995; Crumpler and others, 2001; McGill, 2002). These maps reveal highland, plains, volcanic, and polar units based on morphologic character, albedo, and relative ages using local stratigraphic relations and crater counts. This geologic map of the northern plains is the first published map that covers a significant part of Mars using topography and image data from both the Mars Global Surveyor and Mars Odyssey missions. The new data provide a fresh perspective on the geology of the region that reveals many previously unrecognizable units, features, and temporal relations. In addition, we adapted and instituted terrestrial mapping methods and stratigraphic conventions that we think result in a clearer and more objective map. We focus on mapping with the intent of reconstructing the history of geologic activity within the northern plains, including deposition, volcanism, erosion, tectonism, impact cratering, and other processes with the aid of comprehensive crater-density determinations. Mapped areas include all

  4. HUBBLE SPOTS NORTHERN HEMISPHERIC CLOUDS ON URANUS

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Using visible light, astronomers for the first time this century have detected clouds in the northern hemisphere of Uranus. The newest images, taken July 31 and Aug. 1, 1997 with NASA Hubble Space Telescope's Wide Field and Planetary Camera 2, show banded structure and multiple clouds. Using these images, Dr. Heidi Hammel (Massachusetts Institute of Technology) and colleagues Wes Lockwood (Lowell Observatory) and Kathy Rages (NASA Ames Research Center) plan to measure the wind speeds in the northern hemisphere for the first time. Uranus is sometimes called the 'sideways' planet, because its rotation axis is tipped more than 90 degrees from the planet's orbit around the Sun. The 'year' on Uranus lasts 84 Earth years, which creates extremely long seasons - winter in the northern hemisphere has lasted for nearly 20 years. Uranus has also been called bland and boring, because no clouds have been detectable in ground-based images of the planet. Even to the cameras of the Voyager spacecraft in 1986, Uranus presented a nearly uniform blank disk, and discrete clouds were detectable only in the southern hemisphere. Voyager flew over the planet's cloud tops near the dead of northern winter (when the northern hemisphere was completely shrouded in darkness). Spring has finally come to the northern hemisphere of Uranus. The newest images, both the visible-wavelength ones described here and those taken a few days earlier with the Near Infrared and Multi-Object Spectrometer (NICMOS) by Erich Karkoschka (University of Arizona), show a planet with banded structure and detectable clouds. Two images are shown here. The 'aqua' image (on the left) is taken at 5,470 Angstroms, which is near the human eye's peak response to wavelength. Color has been added to the image to show what a person on a spacecraft near Uranus might see. Little structure is evident at this wavelength, though with image-processing techniques, a small cloud can be seen near the planet's northern limb (rightmost

  5. All Christians? Experiences of science educators in Northern Ireland

    NASA Astrophysics Data System (ADS)

    Murphy, Colette; Hickey, Ivor; Beggs, Jim

    2010-03-01

    In this paper we respond to Staver's article (this issue) on an attempt to resolve the discord between science and religion. Most specifically, we comment on Staver's downplaying of difference between Catholics and Protestants in order to focus on the religion-science question. It is our experience that to be born into one or other of these traditions in some parts of the world (especially Northern Ireland) resulted in starkly contrasting opportunities, identities and practices in becoming and being science educators. The paper starts with a short contextual background to the impact of religion on schooling and higher education in Northern Ireland. We then explore the lives and careers of three science/religious educators in Northern Ireland: Catholic (Jim) and Protestant (Ivor) males who are contemporaries and whose experience spans pre-Troubles to post-conflict and a Catholic female (Colette) who moved to Northern Ireland during the Troubles as a teenager. Finally, we discuss the situation regarding the teaching of creationism and evolution in Northern Ireland—an issue has recently generated high public interest. The Chair of the Education Committee of the Northern Ireland Assembly recently stated that "creationism is not for the RE class because I believe that it can stand scientific scrutiny and that is a debate which I am quite happy to encourage and be part of…" (News Letter 2008). It could be the case that the evolution debate is being fuelled as a deliberate attempt to undermine some of the post-conflict collaboration projects between schools and communities in Northern Ireland.

  6. Carbon Cycling in Northern Peatlands

    NASA Astrophysics Data System (ADS)

    Schultz, Colin

    2010-11-01

    Northern peatlands span only 3 million square kilometers, about 3% of the terrestrial area of the globe, yet they represent a significant terrestrial sink for carbon dioxide. They are also important emitters of methane, an even more potent greenhouse gas. Despite their substantial role in the global carbon cycle, peatlands are not typically incorporated into global climate models. The AGU Monograph Carbon Cycling in Northern Peatlands, edited by Andrew J. Baird, Lisa R. Belyea, Xavier Comas, A. S. Reeve, and Lee D. Slater, looks at the disproportionate role peatlands play in the global carbon budget. In this interview, Eos talks with Andy Baird, University of Leeds, Leeds, United Kingdom.

  7. Comparison of survival patterns of northern and southern genotypes of the North American tick Ixodes scapularis (Acari: Ixodidae) under northern and southern conditions

    USGS Publications Warehouse

    Ginsberg, Howard S.; Rulison, Eric L.; Azevedo, Alexandra; Pang, Genevieve C.; Kuczaj, Isis M.; Tsao, Jean I.; LeBrun, Roger A.

    2014-01-01

    BackgroundSeveral investigators have reported genetic differences between northern and southern populations of Ixodes scapularis in North America, as well as differences in patterns of disease transmission. Ecological and behavioral correlates of these genetic differences, which might have implications for disease transmission, have not been reported. We compared survival of northern with that of southern genotypes under both northern and southern environmental conditions in laboratory trials.MethodsSubadult I. scapularis from laboratory colonies that originated from adults collected from deer from several sites in the northeastern, north central, and southern U.S. were exposed to controlled conditions in environmental chambers. Northern and southern genotypes were exposed to light:dark and temperature conditions of northern and southern sites with controlled relative humidities, and mortality through time was recorded.ResultsTicks from different geographical locations differed in survival patterns, with larvae from Wisconsin surviving longer than larvae from Massachusetts, South Carolina or Georgia, when held under the same conditions. In another experiment, larvae from Florida survived longer than larvae from Michigan. Therefore, survival patterns of regional genotypes did not follow a simple north–south gradient. The most consistent result was that larvae from all locations generally survived longer under northern conditions than under southern conditions.ConclusionsOur results suggest that conditions in southern North America are less hospitable than in the north to populations of I. scapularis. Southern conditions might have resulted in ecological or behavioral adaptations that contribute to the relative rarity of I. scapularis borne diseases, such as Lyme borreliosis, in the southern compared to the northern United States.

  8. Stratigraphy of the Martian northern plains

    NASA Technical Reports Server (NTRS)

    Tanaka, K. L.

    1993-01-01

    The northern plains of Mars are roughly defined as the large continuous region of lowlands that lies below Martian datum, plus higher areas within the region that were built up by volcanism, sedimentation, tectonism, and impacts. These northern lowlands span about 50 x 10(exp 6) km(sup 2) or 35 percent of the planet's surface. The age and origin of the lowlands continue to be debated by proponents of impact and tectonic explanations. Geologic mapping and topical studies indicate that volcanic, fluvial, and eolian deposition have played major roles in the infilling of this vast depression. Periglacial, glacial, fluvial, eolian, tectonic, and impact processes have locally modified the surface. Because of the northern plains' complex history of sedimentation and modification, much of their stratigraphy was obscured. Thus the stratigraphy developed is necessarily vague and provisional: it is based on various clues from within the lowlands as well as from highland areas within and bordering the plains. The results are summarized.

  9. Seasonal Changes in Titan's Southern Stratosphere

    NASA Technical Reports Server (NTRS)

    Nixon, C. A.; Bjoraker, G. L.; Achterberg, R. K.; Teanby, N. A.; Coustenis, A.; Jennings, D. E.; Cottini, V.; Irwin, P. G.; Flasar, F. M.

    2012-01-01

    In August 2009 Titan passed through northern spring equinox, and the southern hemisphere passed into fall. Since then, the moon's atmosphere has been closely watched for evidence of the expected seasonal reversal of stratospheric circulation, with increased northern insolation leading to upwelling, and consequent downwelling at southern high latitudes. If the southern winter mirrors the northern winter, this circulation will be traced by increases in short-lived gas species advected downwards from the upper atmosphere to the stratosphere. The Cassini spacecraft in orbit around Saturn carries on board the Composite Infrared Spectrometer (CIRS), which has been actively monitoring the trace gas populations through measurement of the intensity of their infrared emission bands (7-1000 micron). In this presentation we will show fresh evidence from recent CIRS measurements in June 2012, that the shortest-lived and least abundant minor species (C3H4, C4H2, C6H6, HC3N) are indeed increasing dramatically southwards of 50S in the lower stratosphere. Intriguingly, the more stable gases (C2H2, HCN, CO2) have yet to show this trend, and continue to exhibit their 'summer' abundances, decreasing towards the south pole. Possible chemical and dynamical explanations of these results will be discussed , along with the potential of future CIRS measurements to monitor and elucidate these seasonal changes.

  10. Climate impacts on northern Canada: regional background.

    PubMed

    Prowse, Terry D; Furgal, Chris; Bonsal, Barrie R; Peters, Daniel L

    2009-07-01

    Understanding the implications of climate change on northern Canada requires a background about the size and diversity of its human and biogeophysical systems. Occupying an area of almost 40% of Canada, with one-third of this contained in Arctic islands, Canada's northern territories consist of a diversity of physical environments unrivaled around the circumpolar north. Major ecozones composed of a range of landforms, climate, vegetation, and wildlife include: Arctic, boreal and taiga cordillera; boreal and taiga plains; taiga shield; and northern and southern Arctic. Although generally characterized by a cold climate, there is an enormous range in air temperature with mean annual values being as high as -5 degrees C in the south to as low as -20 degrees C in the high Arctic islands. A similar contrast characterizes precipitation, which can be > 700 mm y(-1) in some southern alpine regions to as low as 50 mm y(-1) over islands of the high Arctic. Major freshwater resources are found within most northern ecozones, varying from large glaciers or ice caps and lakes to extensive wetlands and peat lands. Most of the North's renewable water, however, is found within its major river networks and originates in more southerly headwaters. Ice covers characterize the freshwater systems for multiple months of the year while permafrost prevails in various forms, dominating the terrestrial landscape. The marine environment, which envelops the Canadian Arctic Archipelago, is dominated by seasonal to multiyear sea ice often several meters thick that plays a key role in the regional climate. Almost two-thirds of northern Canadian communities are located along coastlines with the entire population being just over 100 000. Most recent population growth has been dominated by an expansion of nonaboriginals, primarily the result of resource development and the growth of public administration. The economies of northern communities, however, remain quite mixed with traditional land

  11. Northern red oak volume growth on four northern Wisconsin habitat types

    Treesearch

    Michael Demchik; Kevin M. Schwartz; Rory Braun; Eric Scharenbrock

    2014-01-01

    Northern red oak (Quercus rubra) grows across much of Wisconsin. Using site factors to aid in prediction of volume and basal area increment facilitates management of red oak and other species of interest. Currently, habitat type (Wisconsin Habitat Type Classification System) is often determined when stands are inventoried. If habitat type were...

  12. Building the New Northern Ontario Rural Medical School.

    ERIC Educational Resources Information Center

    Rourke, James T. B.

    2002-01-01

    Opening in 2004, the new Northern Ontario Rural Medical School will address the rural doctor shortage in Canada. Supported by Laurentian University and Lakehead University, learning sites will be in hospitals, community clinics, and physicians' offices throughout northern Ontario. The curriculum will be patient-centered and clinical problem-based…

  13. Northern forest lands: resident attitudes and resource use

    Treesearch

    Herbert E. Echelberger; Albert E. Luloff; Frederick E. Schmidt; Frederick E. Schmidt

    1991-01-01

    Describes socioeconomic characteristics of residents of northern New Hampshire and northeastern Vermont; their level of participation in outdoor recreational activities; perceptions of community problems; and attitudes concerning local versus regional planning, public ownership of northern forest lands, and other pertinent issues with respect to changes in patterns of...

  14. 7 CFR 457.144 - Northern potato crop insurance-processing quality endorsement.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 6 2011-01-01 2011-01-01 false Northern potato crop insurance-processing quality... Northern potato crop insurance—processing quality endorsement. The Northern Potato Crop Insurance.... Definitions Broker. Any business enterprise regularly engaged in the buying and selling of processing potatoes...

  15. 7 CFR 457.144 - Northern potato crop insurance-processing quality endorsement.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 6 2014-01-01 2014-01-01 false Northern potato crop insurance-processing quality... Northern potato crop insurance—processing quality endorsement. The Northern Potato Crop Insurance.... Definitions Broker. Any business enterprise regularly engaged in the buying and selling of processing potatoes...

  16. 7 CFR 457.144 - Northern potato crop insurance-processing quality endorsement.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 6 2013-01-01 2013-01-01 false Northern potato crop insurance-processing quality... Northern potato crop insurance—processing quality endorsement. The Northern Potato Crop Insurance.... Definitions Broker. Any business enterprise regularly engaged in the buying and selling of processing potatoes...

  17. 7 CFR 457.144 - Northern potato crop insurance-processing quality endorsement.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 6 2012-01-01 2012-01-01 false Northern potato crop insurance-processing quality... Northern potato crop insurance—processing quality endorsement. The Northern Potato Crop Insurance.... Definitions Broker. Any business enterprise regularly engaged in the buying and selling of processing potatoes...

  18. Seasonal Variation of High-Latitude Geomagnetic Activity in Individual Years

    NASA Astrophysics Data System (ADS)

    Tanskanen, E. I.; Hynönen, R.; Mursula, K.

    2017-10-01

    We study the seasonal variation of high-latitude geomagnetic activity in individual years in 1966-2014 (solar cycles 20-24) by identifying the most active and the second most active season based on westward electrojet indices AL (1966-2014) and IL (1995-2014). The annual maximum is found at either equinox in two thirds and at either solstice in one third of the years examined. The traditional two-equinox maximum pattern is found in roughly one fourth of the years. We found that the seasonal variation of high-latitude geomagnetic activity closely follows the solar wind speed. While the mechanisms leading to the two-equinox maxima pattern are in operation, the long-term change of solar wind speed tends to mask the effect of these mechanisms for individual years. Large cycle-to-cycle variation is found in the seasonal pattern: equinox maxima are more common during cycles 21 and 22 than in cycles 23 or 24. Exceptionally long winter dominance in high-latitude activity and solar wind speed is seen in the declining phase of cycle 23, after the appearance of the long-lasting low-latitude coronal hole.

  19. Site index comparisons among northern hardwoods in northern Wisconsin and Upper Michigan.

    Treesearch

    Willard H. Carmean

    1979-01-01

    Compares site index for 13 species found in even-aged northern hardwood stands. Shows that these species differ greatly in site index when growing together, but can be grouped into four general site index classes. Site relations between several species differed with soil drainage.

  20. Photometrical Observations "SBIRS GEO-2"

    NASA Astrophysics Data System (ADS)

    Sukhov, P. P.; Epishev, V. P.; Karpenko, G. F.; Sukhov, K. P.; Kudak, V. I.

    2015-08-01

    Photometrical observations GSS "SBIRS GEO 2" in B,V,R filters were carried near the equinoxes 2014-2015. Used velocity electrophotometer based on the FEU-79 in the pulse-counting mode. Received more than 25 light curves. From the known dimensions are defined; effective reflecting area - Sγλ, the spectral reflectance index - γλ, periods of light variation. Color-indices showed that in the reflected light flux from the GSS prevails "red" component. In the light curves are periodically dips and specular flash. This shows that GSS orbit is not in a static position specified triaxial orientation as in dynamic motion. Assumed following dynamics of the satellite "SBIRS GEO 2" in orbit. Helical scanning the Earth's surface visible infrared sensors satellite occurs with a period P1 = 15.66 sec. and swinging of the GSS about the direction of the motion vector of the satellite in an orbit with P2 = 62.64 sec., from the northern to the southern pole. Thus, during the period of swinging GSS going on 2 scan the visible part of the northern and southern hemispheres. In some dates observations dynamics work satellite in orbit changed.

  1. A Grammar of Northern Mao (Mawes Aas'e)

    ERIC Educational Resources Information Center

    Ahland, Michael Bryan

    2012-01-01

    Northern Mao is an endangered Afroasiatic-Omotic language of western Ethiopia with fewer than 5,000 speakers. This study is a comprehensive grammar of the language, written from a functional/typological perspective which embraces historical change as an explanation for synchronic structure. The grammar introduces the Northern Mao people, aspects…

  2. NPDES Permit for Northern Border Pipeline Company in Montana

    EPA Pesticide Factsheets

    Under NPDES permit MT-0030791, the Northern Border Pipeline Company is authorized to discharge from locations along the Northern Border Gas Transmission Pipeline located within the exterior boundaries of the Fort Peck Indian Reservation, Montana.

  3. Response of northern hardwood forests to nutrient perturbation

    Treesearch

    Christopher Eagar; Scott Bailey; Amey Bailey

    1999-01-01

    Substantial amounts of calcium have been depleted from the soils of northern hardwood forests in northern New Engtand over the past 50 years. Portions of this depleted calcium have been incorporated into the biomass of the aggrading forests; however, significant amounts have been leached into drainage waters and lost from the ecosystem.

  4. Northern Forest DroughtNet: A New Framework to Understand Impacts of Precipitation Change on the Northern Forest Ecosystem

    NASA Astrophysics Data System (ADS)

    Asbjornsen, H.; Rustad, L.; Templer, P. H.; Jennings, K.; Phillips, R.; Smith, M.

    2014-12-01

    Recent trends and projections for future change for the U.S. northern forests suggest that the region's climate is becoming warmer, wetter, and, ironically, drier, with more precipitation occurring as large events, separated by longer periods with no precipitation. However, to date, precipitation manipulation experiments conducted in forest ecosystems represent only ~5% of all such experiments worldwide, and our understanding of how the mesic-adapted northern forest will respond to greater frequency and intensity of drought in the future is especially poor. Several important challenges have hampered previous research efforts to conduct forest drought experiments and draw robust conclusions, including difficulties in reducing water uptake by deep and lateral tree roots, logistical and financial constraints to establishing and maintaining large-scale field experiments, and the lack of standardized approaches for determining the appropriate precipitation manipulation treatment (e.g., amount and timing of throughfall displacement), designing and constructing the throughfall displacement infrastructure, identifying key response variables, and collecting and analyzing the field data. The overarching goal of this project is to establish a regional research coordination network - Northern Forest DroughtNet - to investigate the impacts of changes in the amount and distribution of precipitation on the hydrology, biogeochemistry, and carbon (C) cycling dynamics of northern temperate forests. Specific objectives include the development of a standard prototype for conducting precipitation manipulation studies in forest ecosystems (in collaboration with the international DroughtNet-RCN) and the implementation of this prototype drought experiment at the Hubbard Brook Experimental Forest. Here, we present the advances made thus far towards achieving the objectives of Northern Forest DroughtNet, plans for future work, and an invitation to the larger scientific community interested

  5. Survey of northern informal and formal mental health practitioners

    PubMed Central

    O'Neill, Linda; George, Serena; Sebok, Stefanie

    2013-01-01

    Background This survey is part of a multi-year research study on informal and formal mental health support in northern Canada involving the use of qualitative and quantitative data collection and analysis methods in an effort to better understand mental health in a northern context. Objective The main objective of the 3-year study was to document the situation of formal and informal helpers in providing mental health support in isolated northern communities in northern British Columbia, northern Alberta, Yukon, Northwest Territories and Nunavut. The intent of developing a survey was to include more participants in the research and access those working in small communities who would be concerned regarding confidentiality and anonymity due to their high profile within smaller populations. Design Based on the in-depth interviews from the qualitative phase of the project, the research team developed a survey that reflected the main themes found in the initial qualitative analysis. The on-line survey consisted of 26 questions, looking at basic demographic information and presenting lists of possible challenges, supports and client mental health issues for participants to prioritise. Results Thirty-two participants identified various challenges, supports and client issues relevant to their mental health support work. A vast majority of the respondents felt prepared for northern practice and had some level of formal education. Supports for longevity included team collaboration, knowledgeable supervisors, managers, leaders and more opportunities for formal education, specific training and continuity of care to support clients. Conclusion For northern-based research in small communities, the development of a survey allowed more participants to join the larger study in a way that protected their identity and confidentiality. The results from the survey emphasise the need for team collaboration, interdisciplinary practice and working with community strengths as a way to

  6. Silvicultural guide for northern hardwoods in the northeast

    Treesearch

    William B. Leak; Mariko Yamasaki; Robbo. Holleran

    2014-01-01

    This revision of the 1987 silvicultural guide includes updated and expanded silvicultural information on northern hardwoods as well as additional information on wildlife habitat and the management of mixed-wood and northern hardwood-oak stands. The prescription methodology is simpler and more field-oriented. This guide also includes an appendix of familiar tables and...

  7. Reappraisal of the relationship between the northern Nevada rift and Miocene extension in the northern Basin and Range Province

    USGS Publications Warehouse

    Colgan, Joseph P.

    2013-01-01

    The northern Nevada rift is a prominent mafic dike swarm and magnetic anomaly in north-central Nevada inferred to record the Middle Miocene (16.5-15.0 Ma) extension direction in the northern Basin and Range province in the western United States. From the 245°-250° rift direction, Basin and Range extension is inferred to have shifted 45° clockwise to a modern direction of 290°-300° during the late Miocene. The region surrounding the northern Nevada rift was actively extending while the rift formed, and these domains are all characterized by extension oriented 280°-300°. This direction is distinctly different from the rift direction and nearly identical to the modern Basin and Range direction. Although the rate, structural style, and distribution of Basin and Range extension appear to have undergone a significant change in the late Miocene (ca. 10 Ma), the overall spreading direction does not. Middle Miocene extension was directed perpendicular to the axis of the thickest crust formed during Mesozoic shortening and this orientation may reflect gravitational collapse of this thick crust. Orientation of northern Nevada rift dikes may reflect a short-lived regional stress field related to the onset of Yellowstone hotspot volcanism.

  8. Global distributions of ionospheric electric potentials for variable IMF conditions: climatology and near-real time specification

    NASA Astrophysics Data System (ADS)

    Kartalev, M. D.; Papitashvili, V. O.; Keremidarska, V. I.; Grigorov, K. G.; Romanov, D. K.

    2002-03-01

    We report a study of global climatology in the ionospheric electric potentials obtained from combining two algorithms used for mapping of high- and middle/low latitude ionospheric electrodynamics: the LiMIE (http://www.sprl.umich.edu/mist/limie.html) and IMEH (http://geospace.nat.bg) models, respectively. In this combination, the latter model utilizes high-latitude field-aligned current distributions provided by LiMIE for various IMF conditions and different seasons (summer, winter, equinox). For the testing purposes, we developed a Web-based interface which provides global distributions of the ionospheric electric potential in near-real time utilizing solar wind observations made onboard the NASA's ACE spacecraft upstream at L1. We discuss the electric potential global modeling over both the northern and southern hemispheres and consider some implications for the solar cycle studies and space weather forecasting.

  9. Hubble Spots Northern Hemispheric Clouds on Uranus

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Using visible light, astronomers for the first time this century have detected clouds in the northern hemisphere of Uranus. The newest images, taken July 31 and Aug. 1, 1997 with NASA Hubble Space Telescope's Wide Field and Planetary Camera 2, show banded structure and multiple clouds. Using these images, Dr. Heidi Hammel (Massachusetts Institute of Technology) and colleagues Wes Lockwood (Lowell Observatory) and Kathy Rages (NASA Ames Research Center) plan to measure the wind speeds in the northern hemisphere for the first time.

    Uranus is sometimes called the 'sideways' planet, because its rotation axis tipped more than 90 degrees from the planet's orbit around the Sun. The 'year' on Uranus lasts 84 Earth years, which creates extremely long seasons - winter in the northern hemisphere has lasted for nearly 20 years. Uranus has also been called bland and boring, because no clouds have been detectable in ground-based images of the planet. Even to the cameras of the Voyager spacecraft in 1986, Uranus presented a nearly uniform blank disk, and discrete clouds were detectable only in the southern hemisphere. Voyager flew over the planet's cloud tops near the dead of northern winter (when the northern hemisphere was completely shrouded in darkness).

    Spring has finally come to the northern hemisphere of Uranus. The newest images, both the visible-wavelength ones described here and those taken a few days earlier with the Near Infrared and Multi-Object Spectrometer (NICMOS) by Erich Karkoschka (University of Arizona), show a planet with banded structure and detectable clouds.

    Two images are shown here. The 'aqua' image (on the left) is taken at 5,470 Angstroms, which is near the human eye's peak response to wavelength. Color has been added to the image to show what a person on a spacecraft near Uranus might see. Little structure is evident at this wavelength, though with image-processing techniques, a small cloud can be seen near the planet's northern limb

  10. Northern tropical Atlantic climate since late Medieval times from Northern Caribbean coral geochemistry

    NASA Astrophysics Data System (ADS)

    Kilbourne, K. H.; Xu, Y.

    2015-12-01

    Paleoclimate reconstructions of different global climate modes over the last 1000 years provide the basis for testing the relative roles of forced and unforced variability climate system, which can help us improve projections of future climate change. The Medieval Climate Anomaly (MCA) has been characterized by a combination of persistent La Niña-like conditions, a positive North Atlantic Oscillation (+NAO), and increased Atlantic Meridional Overturning Circulation (AMOC). The northern tropical Atlantic is sensitive to each of these climate patterns, but not all of them have the same regional fingerprint in the modern northern tropical Atlantic. The relative influence of different processes related to these climate patterns can help us better understand regional responses to climate change. The regional response of the northern tropical Atlantic is important because the tropical Atlantic Ocean is a large source of heat and moisture to the global climate system that can feedback onto global climate patterns. This study presents new coral Sr/Ca and δ18O data from the northern tropical Atlantic (Anegada, British Virgin Islands). Comparison of the sub-fossil corals that grew during the 13th and 14th Centuries with modern coral geochemical data from this site indicates relatively cooler mean conditions with a decrease in the oxygen isotopic composition of the water consistent with lower salinities. Similar average annual cycles between modern and sub-fossil Sr/Ca indicate no change in seasonal temperature range, but a difference in the relative phasing of the δ18O seasonal cycles indicates that the fresher mean conditions may be due to a more northerly position of the regional salinity front. This localized response is consistent with some, but not all of the expected regional responses to a La Niña-like state, a +NAO state, and increased AMOC. Understanding these differences can provide insight into the relative importance of advection versus surface fluxes for

  11. Impacts of Northern Pike on stocked Rainbow Trout in Pactola Reservoir, South Dakota

    USGS Publications Warehouse

    Scheibel, Natalie C.; Dembkowski, Daniel J.; Davis, Jacob L.; Chipps, Steven R.

    2016-01-01

    Establishment of nonnative Northern Pike Esox lucius in Pactola Reservoir, South Dakota, has prompted concern among biologists about the influence of this species on the lake’s intensively managed salmonid fisheries. Ancedotal information suggests that catch rates of Rainbow Trout Oncorhynchus mykiss have declined while mean size and abundance of Northern Pike has increased, although quantitative information on diet and growth of the Northern Pike population is lacking. To address potential interactions between Northern Pike and Rainbow Trout, we assessed size-dependent predation by Northern Pike on Rainbow Trout and determined the relative energetic contribution of stocked Rainbow Trout to Northern Pike growth using bioenergetics modeling. Stable isotopes combined with traditional diet analyses revealed that smaller Northern Pike (<600 mm TL) consumed primarily centrarchids and Rainbow Smelt Osmerus mordax, and Rainbow Trout contributed less than 10% to their annual energy consumption. In contrast, larger Northern Pike (≥600 mm TL) consumed primarily Rainbow Trout, which accounted for 56% of their annual energy consumption. Combining estimates of Northern Pike predation with production costs of catchable-size Rainbow Trout revealed that annual economic losses ranged from US$15,259 to $24,801 per year. Over its lifespan, an age-10 Northern Pike was estimated to consume ~117 Rainbow Trout worth approximately $340. Thus, Northern Pike predation substantially influences salmonid management initiatives and is likely a primary factor contributing to reduced Rainbow Trout abundance and return to anglers in Pactola Reservoir. Strategies for reducing Northern Pike predation on Rainbow Trout include increasing the size of stocked fish or altering the timing and spatial distribution of stocking events.

  12. Nitric oxide nightglow and Martian mesospheric circulation from MAVEN/IUVS observations and LMD-MGCM predictions

    NASA Astrophysics Data System (ADS)

    Stiepen, A.; Jain, S. K.; Schneider, N. M.; Deighan, J. I.; González-Galindo, F.; Gérard, J.-C.; Milby, Z.; Stevens, M. H.; Bougher, S.; Evans, J. S.; Stewart, A. I. F.; Chaffin, M. S.; Crismani, M.; McClintock, W. E.; Clarke, J. T.; Holsclaw, G. M.; Montmessin, F.; Lefèvre, F.; Forget, F.; Lo, D. Y.; Hubert, B.; Jakosky, B. M.

    2017-05-01

    We report results from a study of nitric oxide nightglow over the northern hemisphere of Mars during winter, the southern hemisphere during fall equinox, and equatorial latitudes during summer in the northern hemisphere based on observations of the δ and γ bands between 190 and 270 nm by the Imaging UltraViolet Spectrograph (IUVS) on the Mars Atmosphere and Volatile EvolutioN mission (MAVEN) spacecraft. The emission reveals recombination of N and O atoms dissociated on the dayside of Mars and transported to the nightside. We characterize the brightness (from 0.2 to 30 kR) and altitude (from 40 to 115 km) of the NO nightglow layer, as well as its topside scale height (mean of 11 km). We show the possible impact of atmospheric waves forcing longitudinal variability, associated with an increased brightness by a factor of 3 in the 140-200° longitude region in the northern hemisphere winter and in the -102° to -48° longitude region at summer. Such impact to the NO nightglow at Mars was not seen before. Quantitative comparison with calculations of the LMD-MGCM (Laboratoire de Météorologie Dynamique-Mars Global Climate Model) suggests that the model globally reproduces the trends of the NO nightglow emission and its seasonal variation and also indicates large discrepancies (up to a factor 50 fainter in the model) in northern winter at low to middle latitudes. This suggests that the predicted transport is too efficient toward the night winter pole in the thermosphere by ˜20° latitude north.

  13. Northern Conference Film and Video Guide on Native and Northern Justice Issues.

    ERIC Educational Resources Information Center

    Simon Fraser Univ., Burnaby (British Columbia).

    Intended for teachers and practitioners, this film and video guide contains 235 entries pertaining to the administration of justice, culture and lifestyle, and education and services in northern Canada. It is divided into eight sections: Native lifestyle (97 items); economic development (28), rights and self-government (20); education and training…

  14. 68. Photocopy of drawing (from print, Burlington Northern Engineering Office) ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    68. Photocopy of drawing (from print, Burlington Northern Engineering Office) STRESS DIAGRAM - Burlington Northern Railroad Bridge, Spanning Willamette River at River Mile 6.9, Portland, Multnomah County, OR

  15. Paludification and forest retreat in northern oceanic environments.

    PubMed

    Crawford, R M M; Jeffree, C E; Rees, W G

    2003-01-01

    Examination of temperature variations over the past century for Europe and the Arctic from northern Norway to Siberia suggests that variations in the North Atlantic Oscillation are associated with an increase in oceanicity in certain maritime regions. A southward depression of the tree line in favour of wet heaths, bogs and wetland tundra communities is also observed in northern oceanic environments. The physiological basis for this change in ecological succession from forest to bog is discussed in relation to the long-term effects of flooding on tree survival. The heightened values currently detected in the North Atlantic Oscillation Index, together with rising winter temperatures, and increased rainfall in many areas in northern Europe, presents an increasing risk of paludification with adverse consequences for forest regeneration, particularly in areas with oceanic climates. Climatic warming in oceanic areas may increase the area covered by bogs and, contrary to general expectations, lead to a retreat rather than an advance in the northern limit of the boreal forest. High water-table levels are not automatically detrimental to forest survival as can be seen in swamp, bottom land and mangrove forests. Consequently, the inhibitory effects of flooding on tree survival and regeneration in northern regions should not be uncritically accepted as merely due to high water levels. Evidence is discussed which suggests that physiological and ecological factors may interact to inhibit forest regeneration in habitats where there is a risk of prolonged winter-flooding combined with warmer winters and cool moist summers.

  16. Paludification and Forest Retreat in Northern Oceanic Environments

    PubMed Central

    CRAWFORD, R. M. M.; JEFFREE, C. E.; REES, W. G.

    2003-01-01

    Examination of temperature variations over the past century for Europe and the Arctic from northern Norway to Siberia suggests that variations in the North Atlantic Oscillation are associated with an increase in oceanicity in certain maritime regions. A southward depression of the treeline in favour of wet heaths, bogs and wetland tundra communities is also observed in northern oceanic environments. The physiological basis for this change in ecological succession from forest to bog is discussed in relation to the long‐term effects of flooding on tree survival. The heightened values currently detected in the North Atlantic Oscillation Index, together with rising winter temperatures, and increased rainfall in many areas in northern Europe, presents an increasing risk of paludification with adverse consequences for forest regeneration, particularly in areas with oceanic climates. Climatic warming in oceanic areas may increase the area covered by bogs and, contrary to general expectations, lead to a retreat rather than an advance in the northern limit of the boreal forest. High water‐table levels are not automatically detrimental to forest survival as can be seen in swamp, bottomland and mangrove forests. Consequently, the inhibitory effects of flooding on tree survival and regeneration in northern regions should not be uncritically accepted as merely due to high water levels. Evidence is discussed which suggests that physiological and ecological factors may interact to inhibit forest regeneration in habitats where there is a risk of prolonged winter‐flooding combined with warmer winters and cool moist summers. PMID:12509342

  17. 76 FR 55345 - Northern New Mexico Resource Advisory Committee

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-07

    ... DEPARTMENT OF AGRICULTURE Forest Service Northern New Mexico Resource Advisory Committee AGENCY: Forest Service, USDA. ACTION: Notice of meeting. SUMMARY: The Northern New Mexico Resource Advisory Committee (NNM RAC) will meet in Albuquerque, New Mexico. The committee is authorized under the Secure Rural...

  18. 76 FR 29722 - Northern New Mexico Resource Advisory Committee

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-23

    ... DEPARTMENT OF AGRICULTURE Forest Service Northern New Mexico Resource Advisory Committee AGENCY: Forest Service, USDA. ACTION: Notice of meeting. SUMMARY: The Northern New Mexico Resource Advisory Committee (NNMRAC) will meet in Albuquerque, New Mexico. The committee is authorized under the Secure Rural...

  19. 77 FR 48949 - Northern New Mexico Resource Advisory Committee

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-15

    ... DEPARTMENT OF AGRICULTURE Forest Service Northern New Mexico Resource Advisory Committee AGENCY: Forest Service, USDA. ACTION: Notice of meeting. SUMMARY: The Northern New Mexico Resource Advisory Committee (NNM RAC) will meet in Albuquerque, New Mexico. The committee is authorized under the Secure Rural...

  20. Developing a topographic model to predict the northern hardwood forest type within Carolina northern flying squirrel (Glaucomys sabrinus coloratus) recovery areas of the southern Appalachians

    USGS Publications Warehouse

    Evans, Andrew; Odom, Richard H.; Resler, Lynn M.; Ford, W. Mark; Prisley, Stephen

    2014-01-01

    The northern hardwood forest type is an important habitat component for the endangered Carolina northern flying squirrel (CNFS; Glaucomys sabrinus coloratus) for den sites and corridor habitats between boreo-montane conifer patches foraging areas. Our study related terrain data to presence of northern hardwood forest type in the recovery areas of CNFS in the southern Appalachian Mountains of western North Carolina, eastern Tennessee, and southwestern Virginia. We recorded overstory species composition and terrain variables at 338 points, to construct a robust, spatially predictive model. Terrain variables analyzed included elevation, aspect, slope gradient, site curvature, and topographic exposure. We used an information-theoretic approach to assess seven models based on associations noted in existing literature as well as an inclusive global model. Our results indicate that, on a regional scale, elevation, aspect, and topographic exposure index (TEI) are significant predictors of the presence of the northern hardwood forest type in the southern Appalachians. Our elevation + TEI model was the best approximating model (the lowest AICc score) for predicting northern hardwood forest type correctly classifying approximately 78% of our sample points. We then used these data to create region-wide predictive maps of the distribution of the northern hardwood forest type within CNFS recovery areas.

  1. 64. Photocopy of drawing (from print, Burlington Northern Engineering Office, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    64. Photocopy of drawing (from print, Burlington Northern Engineering Office, Seattle) STRESS SHEET - Burlington Northern Railroad Bridge, Spanning Willamette River at River Mile 6.9, Portland, Multnomah County, OR

  2. The Maritime Cultural Landscape of Northern Patagonia

    NASA Astrophysics Data System (ADS)

    Lira, Nicolás

    2017-12-01

    This article is a contribution to the study of the indigenous navigation and its boats in the region of northern Patagonia. This article also aims to contribute to the understanding of indigenous navigation practices and technologies and their origins from prehistoric times to the mid-twentieth century. It presents and discusses the concept of Westerdahl's Maritime Cultural Landscape in relation to other landscape concepts. This model is applied to northern Patagonia in order to discuss if it is possible to speak of a true maritime culture in the region. For this purpose, archaeological, historical and ethnographic data are presented in an integrative and innovative methodology for the discipline. Finally, the Maritime Cultural Landscape model will allow the integration of aquatic and terrestrial landscapes as routes traveled by native inhabitants of northern Patagonia and southern Chile, and propose an important and diversified maritime, river and lake tradition.

  3. [Morphological characteristics of cornea in patients with vernal keratoconjunctivitis by in vivo laser scanning confocal microscopy].

    PubMed

    Le, Qi-hua; Hong, Jia-xu; Zhu, Wen-qing; Sun, Xing-huai; Xu, Jian-jiang

    2011-05-01

    To explore the morphological characteristics on cornea in patients with vernal keratoconjunctivitis (VKC) by the application of in vivo laser scanning confocal microscopy (LSCM). The experimental design was retrospective observation case series (case control study). Twenty-six patients, each diagnosed as bilateral VKC, were enrolled in the study, among which 13 were tarsal form, 5 were bulbar form and the rest were mixed form. Nine patients had the clinical course less than one year, eight subjects longer than three years, and the rest between them. Another twenty-six healthy volunteers with matching age and gender were selected as normal control. All participants had their right eyes examined with the in vivo confocal microscopy (HRT II/RCM). Central cornea and superior peripheral cornea were chosen as the examination points. The images were recorded automatically and cellular density of each layer was analyzed by installed software. Software ImageJ was utilized to analyze the density, diameter, branch number and tortuosity of subbasal nerve fiber in VKC patients. Independent t test was performed to assess the differences on cellular density between VKC patients and normal control, as well as those between central and peripheral cornea in VKC patients. Fisher chi-square test was used to compare the infiltration rate of Langerhans cells in corneal epithelium between VKC patients and controls. ANOVA was applied to assess the differences in cellular density among three subtypes, as well as among different duration of VKC. Independent t-test and chi-square test were applied to analyze the parameters of subbasal nerve fiber. The morphological changes in cornea included the absence of superficial hyperreflective polygonal epithelial cells, infiltration of Langerhans cells in and(or) underneath corneal epithelium and activation of keratocytes in anterior stroma. Corneal epithelium conjunctivalization and stromal neovascularization could be identified in patients with

  4. 75 FR 61786 - Northern Lights Fund Trust, et al.; Notice of Application

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-06

    ...] Northern Lights Fund Trust, et al.; Notice of Application September 30, 2010. AGENCY: Securities and... certain financial instruments. Applicants: Northern Lights Fund Trust (``NLFT''), Arrow Investment Advisors, LLC (``AIA''), and Northern Lights Distributors, LLC (``NLD''). Filing Dates: The application was...

  5. 77 FR 76475 - Environmental Management Site-Specific Advisory Board, Northern New Mexico

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-28

    ... DEPARTMENT OF ENERGY Environmental Management Site-Specific Advisory Board, Northern New Mexico... the Environmental Management Site-Specific Advisory Board (EM SSAB), Northern New Mexico. The Federal... INFORMATION CONTACT: Menice Santistevan, Northern New Mexico Citizens' Advisory Board (NNMCAB), 94 Cities of...

  6. 7 CFR 457.142 - Northern potato crop insurance provisions.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 6 2010-01-01 2010-01-01 false Northern potato crop insurance provisions. 457.142 Section 457.142 Agriculture Regulations of the Department of Agriculture (Continued) FEDERAL CROP INSURANCE CORPORATION, DEPARTMENT OF AGRICULTURE COMMON CROP INSURANCE REGULATIONS § 457.142 Northern potato...

  7. Observations of Thermospheric Horizontal Winds at Watson Lake, Yukon Territory (lambda=65 Deg N)

    NASA Technical Reports Server (NTRS)

    Niciejewski, R. J.; Killeen, T. L.; Solomon, Stanley C.

    1996-01-01

    vernal equinox.

  8. Orbit characteristics of the tristatic EISCAT UHF meteors

    NASA Astrophysics Data System (ADS)

    Szasz, C.; Kero, J.; Meisel, D. D.; Pellinen-Wannberg, A.; Wannberg, G.; Westman, A.

    2008-07-01

    The tristatic EISCAT 930-MHz UHF system is used to determine the absolute geocentric velocities of meteors detected with all three receivers simultaneously at 96 km, the height of the common radar volume. The data used in this study were taken between 2002 and 2005, during four 24-h runs at summer/winter solstice and vernal/autumnal equinox to observe the largest seasonal difference. The observed velocities of 410 tristatic meteors are integrated back through the Earth atmosphere to find their atmospheric entry velocities using an ablation model. Orbit calculations are performed by taking zenith attraction, Earth rotation as well as obliquity of the ecliptic into account. The results are presented in the form of different orbital characteristics. None of the observed meteors appears to be of extrasolar or asteroidal origin; comets, particularly short-period (<200 yr) ones, may be the dominant source for the particles observed. About 40 per cent of the radiants can be associated with the north apex sporadic meteor source and 58 per cent of the orbits are retrograde. There is evidence of resonance gaps at semimajor axis values corresponding to commensurabilities with Jupiter, which may be the first convincing evidence of Jupiter's gravitational influence on the population of small sporadic meteoroids surveyed by radar. The geocentric velocity distribution is bimodal with a prograde population centred around 38 kms-1 and a retrograde population peaking at 59 kms-1. The EISCAT radar system is located close to the Arctic Circle, which means that the North Ecliptic Pole (NEP) is near zenith once every 24 h, i.e. during each observational period. In this particular geometry, the local horizon coincides with the ecliptic plane. The meteoroid influx should therefore be directly comparable throughout the year.

  9. The effect of lunarlike satellites on the orbital infrared light curves of Earth-analog planets.

    PubMed

    Moskovitz, Nicholas A; Gaidos, Eric; Williams, Darren M

    2009-04-01

    We have investigated the influence of lunarlike satellites on the infrared orbital light curves of Earth-analog extrasolar planets. Such light curves will be obtained by NASA's Terrestrial Planet Finder (TPF) and ESA's Darwin missions as a consequence of repeat observations to confirm the companion status of a putative planet and determine its orbit. We used an energy balance model to calculate disk-averaged infrared (bolometric) fluxes from planet-satellite systems over a full orbital period (one year). The satellites are assumed to lack an atmosphere, have a low thermal inertia like that of the Moon, and span a range of plausible radii. The planets are assumed to have thermal and orbital properties that mimic those of Earth, while their obliquities and orbital longitudes of inferior conjunction remain free parameters. Even if the gross thermal properties of the planet can be independently constrained (e.g., via spectroscopy or visible-wavelength detection of specular glint from a surface ocean), only the largest (approximately Mars-sized) lunarlike satellites can be detected by light curve data from a TPF-like instrument (i.e., one that achieves a photometric signal-to-noise ratio of 10 to 20 at infrared wavelengths). Nondetection of a lunarlike satellite can obfuscate the interpretation of a given system's infrared light curve so that it may resemble a single planet with high obliquity, different orbital longitude of vernal equinox relative to inferior conjunction, and in some cases drastically different thermal characteristics. If the thermal properties of the planet are not independently established, then the presence of a lunarlike satellite cannot be inferred from infrared data, which would thus demonstrate that photometric light curves alone can only be used for preliminary study, and the addition of spectroscopic data will be necessary.

  10. A proposed model for the flowering signaling pathway of sugarcane under photoperiodic control.

    PubMed

    Coelho, C P; Costa Netto, A P; Colasanti, J; Chalfun-Júnior, A

    2013-04-25

    Molecular analysis of floral induction in Arabidopsis has identified several flowering time genes related to 4 response networks defined by the autonomous, gibberellin, photoperiod, and vernalization pathways. Although grass flowering processes include ancestral functions shared by both mono- and dicots, they have developed their own mechanisms to transmit floral induction signals. Despite its high production capacity and its important role in biofuel production, almost no information is available about the flowering process in sugarcane. We searched the Sugarcane Expressed Sequence Tags database to look for elements of the flowering signaling pathway under photoperiodic control. Sequences showing significant similarity to flowering time genes of other species were clustered, annotated, and analyzed for conserved domains. Multiple alignments comparing the sequences found in the sugarcane database and those from other species were performed and their phylogenetic relationship assessed using the MEGA 4.0 software. Electronic Northerns were run with Cluster and TreeView programs, allowing us to identify putative members of the photoperiod-controlled flowering pathway of sugarcane.

  11. Vegetative substrates used by larval northern pike in Rainy and Kabetogama Lakes, Minnesota

    Treesearch

    Anne L. Timm; Rodney B. Pierce

    2015-01-01

    Our objective was to identify characteristics of aquatic vegetative communities used as larval northern pike nursery habitat in Rainy and Kabetogama lakes, glacial shield reservoirs in northern Minnesota. Quatrefoil light traps fished at night were used to sample larval northern pike in 11 potential nursery areas. Larval northern pike were most commonly sampled among...

  12. Marine reptiles from the Late Cretaceous of northern Patagonia

    NASA Astrophysics Data System (ADS)

    Gasparini, Z.; Casadio, S.; Fernández, M.; Salgado, L.

    2001-04-01

    During the Campanian-Maastrichtian, Patagonia was flooded by the Atlantic and reduced to an archipelago. Several localities of northern Patagonia have yielded marine reptiles. Analysis of several assemblages suggests that the diversity and abundance of pelagic marine reptiles in northern Patagonia was higher by the end of the Cretaceous than previously thought. Several plesiosaurids, including Aristonectes parvidens and the polycotylid Sulcusuchus, and the first remains of mosasaurinae have been found. The Cretaceous marine reptile record from South America is scanty. Nevertheless, materials described here suggest that Tethyan and Weddelian forms converged in northern Patagonia, as seen with invertebrates.

  13. Auger planting of oak seedlings in northern Arkansas

    Treesearch

    Eric Heitzman; Adrian Grell

    2003-01-01

    Planting oak seedlings to regenerate upland oak forests is a promising but untested silvicultural practice in the Ozark Mountains of northern Arkansas. The stony (cherty) soils of the region make it difficult to dig deep planting holes using conventional hand planting tools. In 2001, we planted 1-0 northern red oak and white oak seedlings in 0.5 to 1 acre group...

  14. The northern hardwood forests of the Anthracite Region

    Treesearch

    C. F. Burnham; M. J. Ferree; F. E. Cunningham

    1947-01-01

    The northern hardwood type forest is found only in the northern counties of the Anthracite Region. It dominates the highlands from Sullivan County on the west, to Monroe County on the east. The early lumbermen back in the 1860's, according to Illick and Frontz, "found (some) valleys, hillsides and mountains covered with a dense growth of enormous white pine...

  15. A test of point-sampling in northern hardwoods

    Treesearch

    Dale S. Solomon

    1975-01-01

    Plot- and point-sampling were compared with a complete inventory of two different stands of northern hardwoods. Prisms with basal-area factors of 5, 10, 20, 30, and 40 and a ¼-acre plot were used. Only the 5-factor prism gave a significantly different estimate. Therefore, a prism factor of 10 or greater is suggested for use in northern hardwoods.

  16. Expansive Northern Volcanic Plains

    NASA Image and Video Library

    2015-04-16

    Mercury northern region is dominated by expansive smooth plains, created by huge amounts of volcanic material flooding across Mercury surface in the past, as seen by NASA MESSENGER spacecraft. The volcanic lava flows buried craters, leaving only traces of their rims visible. Such craters are called ghost craters, and there are many visible in this image, including a large one near the center. Wrinkle ridges cross this scene and small troughs are visible regionally within ghost craters, formed as a result of the lava cooling. The northern plains are often described as smooth since their surface has fewer impact craters and thus has been less battered by such events. This indicates that these volcanic plains are younger than Mercury's rougher surfaces. Instrument: Mercury Dual Imaging System (MDIS) Center Latitude: 60.31° N Center Longitude: 36.87° E Scale: The large ghost crater at the center of the image is approximately 103 kilometers (64 miles) in diameter http://photojournal.jpl.nasa.gov/catalog/PIA19415

  17. Aerial view of reroofing of northern LTA ship hangar, circa ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Aerial view of re-roofing of northern LTA ship hangar, circa 1957. - Marine Corps Air Station Tustin, Northern Lighter Than Air Ship Hangar, Meffett Avenue & Maxfield Street, Tustin, Orange County, CA

  18. Dens of northern flying squirrels in the Pacific Northwest.

    Treesearch

    A.B. Carey; T.M. Wilson; C.C. Maguire; B.L. Biswell

    1997-01-01

    Silvicultural prescriptions to enhance northern flying squirrel (Glaucoinys sabrinus) habitat have been suggested as an aid for recovery of the threatened northern spotted owl (Strix occidentalis caurina). Flying squirrels are hypothesized to be limited by den sites (cavities in trees) and by food (truffles). However, no...

  19. Aspartylglucosaminuria in northern Norway: a molecular and genealogical study.

    PubMed Central

    Tollersrud, O K; Nilssen, O; Tranebjaerg, L; Borud, O

    1994-01-01

    Aspartylglucosaminuria (AGU, McKusick 208400) is an autosomal recessive lysosomal storage disorder. Ninety percent of all patients are from Finland and only sporadic cases have been reported from elsewhere. In northern Norway, however, nine patients from seven families have been diagnosed with AGU. All these Norwegian patients were homozygous for the most prevalent Finnish AGU mutation (AGUFin) and show the polymorphism uniquely associated with AGUFin in Finland. Genealogical investigation of nine parents proved Finnish ancestry in all pedigrees. Therefore, AGU in Norway most likely resulted from immigration of Finnish carriers. These Finnish immigrants originated mostly from the Tornio valley area in northern Finland in a continuous immigration movement from 1700 to 1900. The majority settled in the western part of northern Norway, leading to a "cluster" of AGU in that particular area. The Finnish immigrants intermixed considerably with Lapps and these two ethnic origins should thus be considered as high risk groups for AGUFin in northern Norway. PMID:8064811

  20. Effects of fire in the Northern Great Plains

    USGS Publications Warehouse

    Higgins, Kenneth F.; Kruse, Arnold D.; Piehl, James L.

    1989-01-01

    This publication is a review of selected literature about prescribed burning in the Northern Great Plains (NGP) for management of wildlife. It also will be useful to other resource managers and researchers and to persons interested in the NGP. It is more 'descriptive' than 'interpretative.'The publication is a joint effort of the South Dakota State Cooperative Fish and Wildlife Research Unit (SDCFWRU), South Dakota State University, Brookings; the Northern Prairie Wildlife Research Center (NPWRC), Jamestown, N.D.; and the U.S. Fish and Wildlife Service (USFWS), Fergus Falls, Minn. Manuscript typing and library services were shared between SDCFWRU and NPWRC.This publication (EC 761) is the second of three SDSU Extension circulars on grassland fires. EC 760 is Prescribed burning guidelines in the Northern Great Plains; EC 762 is Annotated bibliography of fire literature relative to northern grasslands in South-Central Canada and North-Central United States and contains many more citations than presented in this publication. All three circulars may be obtained from either the Wildlife and Fisheries Sciences Department; SDSU Box 2206; ph (605) 688-6121; or from the Ag Communications Bulletin Room; SDSU Box 2231; ph (605) 688-5628; both in Brookings, S.D. 57007.

  1. Seasonal variations of nighttime D-region ionosphere in 2013 solar maximum observed from a low-latitude station

    NASA Astrophysics Data System (ADS)

    Tan, Le Minh; Thu, Nguyen Ngoc; Ha, Tran Quoc; Nguyen-Luong, Quang

    2015-10-01

    We present the observation of tweek atmospherics with harmonics m = 1-8 during the solar maximum year, 2013, at Tay Nguyen University, Vietnam (Geog. 12.65° N, 108.02° E). The analysis of 33,690 tweeks on ten international quiet days during 2 months each season, summer (May, August), winter (February, November), and equinox (March, September), shows that tweeks occur about 51 % during summer, 22 % during winter, and 27 % during equinox. The D-region ionosphere is more sharply bounded for harmonics m = 5-6 around an altitude of 85.5 km. The environment of the D-region is more inhomogeneous during winter and equinox seasons. The mean electron density varies from 28.4-225 cm -3, which corresponds to the harmonics m = 1-8 at the mean reflection height of 81.5-87.7 km. The results reveal that the lower reference height in our work as compared to other works is due to the higher level of solar activity. The equivalent electron density profile of the nighttime D-region ionosphere using tweek method during summer, equinox, and winter seasons shows lower values of electron density by 12-58 %, 3-67 %, and 24-76 % than those obtained using the International Reference Ionosphere (IRI-2012) model.

  2. Bereavement Counselling in Uganda and Northern Ireland: A Comparison

    ERIC Educational Resources Information Center

    Montgomery, Lorna; Owen-Pugh, Valerie

    2018-01-01

    Therapeutic interventions for bereavement in Northern Ireland and in the Sub-Saharan African country of Uganda are compared. Semi-structured interviews were conducted with Ugandan (n = 18) and Northern Irish (n = 20) therapists. These were thematically analysed. The findings focused on: the counselling context, the characteristics of counsellors,…

  3. The Quaternary thrust system of the northern Alaska Range

    USGS Publications Warehouse

    Bemis, Sean P.; Carver, Gary A.; Koehler, Richard D.

    2012-01-01

    The framework of Quaternary faults in Alaska remains poorly constrained. Recent studies in the Alaska Range north of the Denali fault add significantly to the recognition of Quaternary deformation in this active orogen. Faults and folds active during the Quaternary occur over a length of ∼500 km along the northern flank of the Alaska Range, extending from Mount McKinley (Denali) eastward to the Tok River valley. These faults exist as a continuous system of active structures, but we divide the system into four regions based on east-west changes in structural style. At the western end, the Kantishna Hills have only two known faults but the highest rate of shallow crustal seismicity. The western northern foothills fold-thrust belt consists of a 50-km-wide zone of subparallel thrust and reverse faults. This broad zone of deformation narrows to the east in a transition zone where the range-bounding fault of the western northern foothills fold-thrust belt terminates and displacement occurs on thrust and/or reverse faults closer to the Denali fault. The eastern northern foothills fold-thrust belt is characterized by ∼40-km-long thrust fault segments separated across left-steps by NNE-trending left-lateral faults. Altogether, these faults accommodate much of the topographic growth of the northern flank of the Alaska Range.Recognition of this thrust fault system represents a significant concern in addition to the Denali fault for infrastructure adjacent to and transecting the Alaska Range. Although additional work is required to characterize these faults sufficiently for seismic hazard analysis, the regional extent and structural character should require the consideration of the northern Alaska Range thrust system in regional tectonic models.

  4. Challenges in assessing food environments in northern and remote communities in Canada.

    PubMed

    Skinner, Kelly; Burnett, Kristin; Williams, Patricia; Martin, Debbie; Stothart, Christopher; LeBlanc, Joseph; Veeraraghavan, Gigi; Sheedy, Amanda

    2016-06-09

    Effective tools for retail food environments in northern and remote communities are lacking. This paper examines the challenges of conducting food environment assessments in northern and remote communities in Canada encountered during our experience with a food costing project. One of the goals of the Paying for Nutrition in the North project is to develop guidelines to improve current food costing tools for northern Canada. Paying for Nutrition illustrates the complex context of measuring food environments in northern and remote communities. Through the development of a food costing methodology guide to assess northern food environments, several contextual issues emerged, including retail store oligopolies in communities; the importance of assessing food quality; informal social food economies; and the challenge of costing the acquisition and consumption of land- and water-based foods. Food environment measures designed for northern and remote communities need to reflect the geographic context in which they are being employed and must include input from local residents.

  5. Northern goshawk (Accipiter gentilis)

    Treesearch

    John R. Squires; Richard T. Reynolds

    1997-01-01

    The Northern Goshawk (hereafter referred to as Goshawk) is a large forest raptor, occupying boreal and temperate forests throughout the Holarctic. In North America, it breeds from Alaska to Newfoundland and south (Fig. 1). This partial migrant winters throughout its breeding range including occasionally the Great Plains and southeastern states; some...

  6. Movements of northern flying squirrels in different-aged forest stands of western Oregon

    USGS Publications Warehouse

    Martin, K.J.; Anthony, R.G.

    1999-01-01

    In western Oregon, northern flying squirrels (Glaucomys sabrinus) are the primary prey species for northern spotted owls (Strix occidentalis caurina), an old-growth associated species. To assess differences between old-growth and second-growth habitat, we livetrapped and radiotagged 39 northern flying squirrels to estimate their home range sizes and describe movements in 2 old-growth and 2 second-growth conifer forest stands in the Cascade Mountains of central Oregon. Sampling periods were summer and fall of 1991-92. Home range sizes averaged 4.9 ha and did not differ (P > 0.30) between the 2 stand types. Male northern flying squirrels had larger (P ??? 0.03) mean home ranges (5.9 ?? 0.8 ha; ?? ?? SE; n = 20) than females (3.9 ?? 0.4 ha; n = 19). Northern flying squirrel movement distances between successive, noncorrelated telemetry locations averaged 71 m (n = 1,090). No correlation was found between distances moved and stand type or sex. Northern flying squirrel's home range sizes, movements, and densities were similar between the 2 stand types. We suggest abundance and movements of northern flying squirrels are not influencing the preferential selection of oldgrowth forests by northern spotted owls.

  7. Detecting the limits of northern and southern lineages of tanoak in northern California

    Treesearch

    Eduardo Sandoval-Castro; Richard S. Dodd

    2015-01-01

    Two chloroplast lineages of tanoak (Notholithocarpus densiflorus) meet between Korbel and Hoopa in the North Coast of California. Our earlier work suggests these lineages arose from southern and northern glacial refugia and this region represents their colonizing fronts. Earlier, we detected only one population of mixed lineages, suggesting that...

  8. Phylogeography of the antilopine wallaroo (Macropus antilopinus) across tropical northern Australia.

    PubMed

    Wadley, Jessica J; Fordham, Damien A; Thomson, Vicki A; Ritchie, Euan G; Austin, Jeremy J

    2016-11-01

    The distribution of antilopine wallaroo, Macropus antilopinus , is marked by a break in the species' range between Queensland and the Northern Territory, coinciding with the Carpentarian barrier. Previous work on M. antilopinus revealed limited genetic differentiation between the Northern Territory and Queensland M. antilopinus populations across this barrier. The study also identified a number of divergent lineages in the Northern Territory, but was unable to elucidate any geographic structure. Here, we re-examine these results to (1) determine phylogeographic patterns across the range of M. antilopinus and (2) infer the biogeographic barriers associated with these patterns. The tropical savannahs of northern Australia: from the Cape York Peninsula in the east, to the Kimberley in the west. We examined phylogeographic patterns in M. antilopinus using a larger number of samples and three mtDNA genes: NADH dehydrogenase subunit 2, cytochrome b, and the control region. Two datasets were generated and analyzed: (1) a subset of samples with all three mtDNA regions concatenated together and (2) all samples for just control region sequences that included samples from the previous study. Analysis included generating phylogenetic trees based on Bayesian analysis and intraspecific median-joining networks. The contemporary spatial structure of M. antilopinus mtDNA lineages revealed five shallow clades and a sixth, divergent lineage. The genetic differences that we found between Queensland and Northern Territory M. antilopinus samples confirmed the split in the geographic distribution of the species. We also found weak genetic differentiation between Northern Territory samples and those from the Kimberley region of Western Australia, possibly due to the Kimberley Plateau-Arnhem Land barrier. Within the Northern Territory, two clades appear to be parapatric in the west, while another two clades are broadly sympatric across the Northern Territory. MtDNA diversity of M

  9. Implementing E-Learning in Northern Ireland: Prospects and Challenges

    ERIC Educational Resources Information Center

    Uhomoibhi, James O.

    2006-01-01

    Purpose: Aims to examine trends in the development of e-learning in Northern Ireland, report on existing policies, practices and issues affecting its implementation across the sectors. Design/methodology/approach: The present study draws on e-learning policies and strategies that have been developed for Northern Ireland. Examples were drawn from…

  10. Geomorphology and landscape organization of a northern peatland complex

    NASA Astrophysics Data System (ADS)

    Richardson, M. C.

    2012-12-01

    The geomorphic evolution of northern peatlands is governed by complex ecohydrological feedback mechanisms and associated hydro-climatic drivers. For example, prevailing models of bog development (i.e. Ingram's groundwater mounding hypothesis and variants) attempt to explicitly link bog dome characteristics to the regional climate based on analytical and numerical models of lateral groundwater flow and the first-order control of water table position on rates of peat accumulation. In this talk I will present new results from quantitative geomorphic analyses of a northern peatland complex at the De Beers Victor diamond mine site in the Hudson Bay Lowlands of northern Ontario. This work capitalizes on spatially-extensive, high-resolution topographic (LiDAR) data to rigorously test analytical and numerical models of bog dome development in this landscape. The analysis and discussion are then expanded beyond individual bog formations to more broadly consider ecohydrological drivers of landscape organization, with implications for understanding and modeling catchment-scale runoff response. Results show that in this landscape, drainage patterns exhibit relatively well-organized characteristics consistent with observed runoff responses in six gauged research catchments. Interpreted together, the results of these geomorphic and hydrologic analyses help refine our understanding of water balance partitioning among different landcover types within northern peatland complexes. These findings can be used to help guide the development of appropriate numerical model structures for hydrologic prediction in ungauged peatland basins of northern Canada.

  11. Climate change vulnerability and adaptation in the Northern Rocky Mountains [Part 2

    Treesearch

    Jessica E. Halofsky; David L. Peterson; S. Karen Dante-Wood; Linh Hoang; Joanne J. Ho; Linda A. Joyce

    2018-01-01

    The Northern Rockies Adaptation Partnership (NRAP) identified climate change issues relevant to resource management in the Northern Rockies (USA) region, and developed solutions intended to minimize negative effects of climate change and facilitate transition of diverse ecosystems to a warmer climate. The NRAP region covers 183 million acres, spanning northern Idaho,...

  12. Climate change vulnerability and adaptation in the Northern Rocky Mountains [Part 1

    Treesearch

    Jessica E. Halofsky; David L. Peterson; S. Karen Dante-Wood; Linh Hoang; Joanne J. Ho; Linda A. Joyce

    2018-01-01

    The Northern Rockies Adaptation Partnership (NRAP) identified climate change issues relevant to resource management in the Northern Rockies (USA) region, and developed solutions intended to minimize negative effects of climate change and facilitate transition of diverse ecosystems to a warmer climate. The NRAP region covers 183 million acres, spanning northern Idaho,...

  13. Biological Correlates of Northern-Southern Italy Differences in IQ

    ERIC Educational Resources Information Center

    Templer, Donald I.

    2012-01-01

    The present study was intended to provide perspective, albeit less than unequivocal, on the research of Lynn (2010) who reported higher IQs in the northern than southern Italian regions. He attributes this to northern Italians having a greater genetic similarity to middle Europeans and southern Italians to Mediterranean people. Higher regional IQ…

  14. Petroleum resource potential GIS of northern Afghanistan

    USGS Publications Warehouse

    Steinshouer, Douglas W.; Klett, Timothy R.; Ulmishek, Gregory F.; Wandrey, Craig J.; Wahl, Ronald R.; Hill, Ronald J.; Pribil, Michael J.; Pawlewicz, Mark J.; King, J. David; Agena, Warren F.; Taylor, David J.; Amirzada, Abdulla; Selab, Amir Mohammad; Mutteh, Abdul-Salam; Haidari, Ghulam Naqshband; Wardak, Moeengul Gullabudeen

    2006-01-01

    The CD-ROM contains an ESRI ArcReader format GIS project presenting the results of a petroleum resource assessment of Northern Afghanistan, and other data used in the petroleum assessment. Geologic, structural, field, well, political, and other GIS layers covering Afghanistan, Northern Afghanistan and adjacent areas, along with associated geochemical and other data tables pertinent to a petroleum assessment are included. The purpose of this GIS is to provide the basic data layers and tables required to support the petroleum assessment, data for further exploration and development, and an index of known data.

  15. Evidence for recent populations bottlenecks in northern spotted owls (Strix occidentalis Caurina)

    Treesearch

    W.Chris Funk; Eric D. Forsman; Matthew Johnson; Thomas D. Mullins; Susan M. Haig

    2009-01-01

    The northern spotted owl (Strix occidentalis caurina) is one of the most controversial threatened subspecies ever listed under the US Endangered Species Act. Despite protection of its remaining forest habitat, recent field studies show continued declines of northern spotted owls. One potential threat to northern spotted owls which has not yet been...

  16. Epigenomics and bolting tolerance in sugar beet genotypes.

    PubMed

    Hébrard, Claire; Peterson, Daniel G; Willems, Glenda; Delaunay, Alain; Jesson, Béline; Lefèbvre, Marc; Barnes, Steve; Maury, Stéphane

    2016-01-01

    In sugar beet (Beta vulgaris altissima), bolting tolerance is an essential agronomic trait reflecting the bolting response of genotypes after vernalization. Genes involved in induction of sugar beet bolting have now been identified, and evidence suggests that epigenetic factors are involved in their control. Indeed, the time course and amplitude of DNA methylation variations in the shoot apical meristem have been shown to be critical in inducing sugar beet bolting, and a few functional targets of DNA methylation during vernalization have been identified. However, molecular mechanisms controlling bolting tolerance levels among genotypes are still poorly understood. Here, gene expression and DNA methylation profiles were compared in shoot apical meristems of three bolting-resistant and three bolting-sensitive genotypes after vernalization. Using Cot fractionation followed by 454 sequencing of the isolated low-copy DNA, 6231 contigs were obtained that were used along with public sugar beet DNA sequences to design custom Agilent microarrays for expression (56k) and methylation (244k) analyses. A total of 169 differentially expressed genes and 111 differentially methylated regions were identified between resistant and sensitive vernalized genotypes. Fourteen sequences were both differentially expressed and differentially methylated, with a negative correlation between their methylation and expression levels. Genes involved in cold perception, phytohormone signalling, and flowering induction were over-represented and collectively represent an integrative gene network from environmental perception to bolting induction. Altogether, the data suggest that the genotype-dependent control of DNA methylation and expression of an integrative gene network participate in bolting tolerance in sugar beet, opening up perspectives for crop improvement. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  17. Timing of the Northern Prince Gustav Ice Stream retreat and the deglaciation of northern James Ross Island, Antarctic Peninsula during the last glacial-interglacial transition

    NASA Astrophysics Data System (ADS)

    Nývlt, Daniel; Braucher, Régis; Engel, Zbyněk; Mlčoch, Bedřich

    2014-09-01

    The Northern Prince Gustav Ice Stream located in Prince Gustav Channel, drained the northeastern portion of the Antarctic Peninsula Ice Sheet during the last glacial maximum. Here we present a chronology of its retreat based on in situ produced cosmogenic 10Be from erratic boulders at Cape Lachman, northern James Ross Island. Schmidt hammer testing was adopted to assess the weathering state of erratic boulders in order to better interpret excess cosmogenic 10Be from cumulative periods of pre-exposure or earlier release from the glacier. The weighted mean exposure age of five boulders based on Schmidt hammer data is 12.9 ± 1.2 ka representing the beginning of the deglaciation of lower-lying areas (< 60 m a.s.l.) of the northern James Ross Island, when Northern Prince Gustav Ice Stream split from the remaining James Ross Island ice cover. This age represents the minimum age of the transition from grounded ice stream to floating ice shelf in the middle continental shelf areas of the northern Prince Gustav Channel. The remaining ice cover located at higher elevations of northern James Ross Island retreated during the early Holocene due to gradual decay of terrestrial ice and increase of equilibrium line altitude. Schmidt hammer R-values are inversely correlated with 10Be exposure ages and could be used as a proxy for exposure history of individual granite boulders in this region and favour the hypothesis of earlier release of boulders with excessive 10Be concentrations from glacier directly at this site. These data provide evidences for an earlier deglaciation of northern James Ross Island when compared with other recently presented cosmogenic nuclide based deglaciation chronologies, but this timing coincides with rapid increase of atmospheric temperature in this marginal part of Antarctica.

  18. Winter prey caching by northern hawk owls in Minnesota

    Treesearch

    Richard R. Schaefer; D. Craig Rudolph; Jesse F. Fagan

    2007-01-01

    Northern Hawk Owls (Surnia ulula) have been reported to cache prey during the breeding season for later consumption, but detailed reports of prey caching during the non-breeding season are comparatively rare. We provided prey to four individual Northern Hawk Owls in wintering areas in northeastern Minnesota during 2001 and 2005 and observed their...

  19. Site index curves for northern hardwoods in northern Wisconsin and Upper Michigan.

    Treesearch

    Willard H. Carmean

    1978-01-01

    Site index curves based on stem analyses were computed for 13 species found in even-aged, second growth northern hardwood stands. These curves showed that most species had similarly-shaped height growth curves in early years, but after 40 years differences in both rate and pattern of growth between species was evident for trees growing on medium and good sites. Most...

  20. 75 FR 80788 - Northern New Mexico Resource Advisory Committee Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-23

    ... DEPARTMENT OF AGRICULTURE Forest Service Northern New Mexico Resource Advisory Committee Meeting AGENCY: Forest Service, USDA. ACTION: Notice of meeting. SUMMARY: The Northern New Mexico Resource Advisory Committee (NNMRAC) will meet in Albuquerque, New Mexico. The committee is meeting as authorized...

  1. Saturn, Approaching Northern Summer

    NASA Image and Video Library

    2016-09-15

    Since NASA's Cassini spacecraft arrived at Saturn in mid-2004, the planet's appearance has changed greatly. The shifting angle of sunlight as the seasons march forward has illuminated the giant hexagon-shaped jet stream around the north polar region, and the subtle bluish hues seen earlier in the mission have continued to fade. Earlier views obtained in 2004 and 2009 (see PIA06077 and PIA11667) demonstrate how drastically the illumination has changed. This view shows Saturn's northern hemisphere in 2016, as that part of the planet nears its northern hemisphere summer solstice in May 2017. Saturn's year is nearly 30 Earth years long, and during its long time there, Cassini has observed winter and spring in the north, and summer and fall in the south. The spacecraft will complete its mission just after northern summer solstice, having observed long-term changes in the planet's winds, temperatures, clouds and chemistry. Cassini scanned across the planet and its rings on April 25, 2016, capturing three sets of red, green and blue images to cover this entire scene showing the planet and the main rings. The images were obtained using Cassini's wide-angle camera at a distance of approximately 1.9 million miles (3 million kilometers) from Saturn and at an elevation of about 30 degrees above the ring plane. The view looks toward the sunlit side of the rings from a sun-Saturn-spacecraft angle, or phase angle, of 55 degrees. Image scale on Saturn is about 111 miles (178 kilometers) per pixel. The exposures used to make this mosaic were obtained just prior to the beginning of a 44-hour movie sequence. http://photojournal.jpl.nasa.gov/catalog/PIA21046

  2. Estimating cull in northern hardwoods

    Treesearch

    W.M. Zillgitt; S.R. Gevorkiantz

    1946-01-01

    Cull in northern hardwood stands is often very heavy and is difficult to estimate. To help clarify this situation and aid the average cruiser to become more accurate in his estimates, the study reported here should prove very helpful.

  3. Trends in Northern Hemisphere surface cyclone frequency and intensity

    USGS Publications Warehouse

    McCabe, G.J.; Clark, M.P.; Serreze, Mark C.

    2001-01-01

    One of the hypothesized effects of global warming from increasing concentrations of greenhouse gases is a change in the frequency and/or intensity of extratropical cyclones. In this study, winter frequencies and intensities of extratropical cyclones in the Northern Hemisphere for the period 1959-97 are examined to determine if identifiable trends are occurring. Results indicate a statistically significant decrease in midlatitude cyclone frequency and a significant increase in high-latitude cyclone frequency. In addition, storm intensity has increased in both the high and midlatitudes. The changes in storm frequency correlate with changes in winter Northern Hemisphere temperature and support hypotheses that global warming may result in a northward shift of storm tracks in the Northern Hemisphere.

  4. Regional Crustal Velocity Models for Northern Arabian Platform and Turkish-Iranian Plateau

    NASA Astrophysics Data System (ADS)

    Aleqabi, G.; Wysession, M.; Ghalib, H.

    2008-12-01

    The geological structure of the Northern Arabian platform and surrounding mountains is dominated by the collision and suturing of the Arabian plate with the Eurasian plate and the formation of the Turkish-Iranian plateau. The structure of the Northern Arabian platform and surrounding region is poorly constrained. A recent deployment of 10 broadband seismometers in northern and central Iraq provides an opportunity to refine velocity models of the region. We have applied the Niching Genetic Algorithm waveform inversion technique to Rayleigh and Love waves traversing the Northern Arabian platform, the Zagros fold belt, the southern Turkish Plateau, the Iranian Plateau. Results show variations in crustal thickness and shear wave velocity between the Northern Arabian platform and the Turkish-Iranian plateau. In general the shear wave velocities are higher in the Northern Arabian platform than in the Plateaus. Variation of shear velocities within each of the provinces reflects the diversity in tectonic environment across the Zagros fold belt and the complex tectonic history of the region. Crustal thickness results show little crustal thickening has occurred due to collision.

  5. Relationship of epithermal gold deposits to large-scale fractures in northern Nevada

    USGS Publications Warehouse

    Ponce, D.A.; Glen, J.M.G.

    2002-01-01

    Geophysical maps of northern Nevada reveal at least three and possibly six large-scale arcuate features, one of which corresponds to the northern Nevada rift that possibly extends more than 1,000 km from the Oregon- Idaho border to southern Nevada. These features may reflect deep discontinuities within the earth's crust, possibly related to the impact of the Yellowstone hot spot. Because mid-Miocene epithermal gold deposits have been shown to correlate with the northern Nevada rift, we investigate the association of other epithermal gold deposits to other similar arcuate features in northern Nevada. Mid-Miocene and younger epithermal gold- silver deposits also occur along two prominent aeromagnetic anomalies west of the northern Nevada rift. Here, we speculate that mid-Miocene deposits formed along deep fractures in association with mid-Miocene rift- related magmatism and that younger deposits preferentially followed these preexisting features. Statistical analysis of the proximity of epithermal gold deposits to these features suggests that epithermal gold deposits in northern Nevada are spatially associated with large-scale crustal features interpreted from geophysical data.

  6. The variability of SE2 tide extracted from TIMED/SABER observations

    NASA Astrophysics Data System (ADS)

    Li, Xing; Wan, Weixing; Ren, Zhipeng; Yu, You

    2017-04-01

    Based on the temperature observations of the SABER/TIMED, the variability of the non-migrating tide SE2 with high resolution (one-day) is analyzed, using the method from Li et al., [2015]. From the temperature observation data measured in the mesosphere and lower atmosphere region (MLT, 70-110 km altitudes) and at the low- and mid -latitudes (45S - 45N) from2002 to 2012), we obtained the non-migrating tide SE2 and further studied it in detail. It is found that the climatological features (large time scale variability and spatial distribution) of the SE2 tidal component are similar with the results from the previous researches, which are picked up from the interpolated data with 60-day resolution. The climatological features are that the SE2 tidal component manifests mainly at the low-mid latitudes around 30. The northern hemisphere tidal amplitudes below 110 km are larger than the southern hemisphere tide, at the same time, its peaks below 110 km mainly present between 100 and 110 km altitude; the tidal amplitudes below 110 km occur a north-south asymmetry about the equator in the annual variation: in the southern hemisphere, SE2 occurs with an obvious annual variation with a maximum of tidal amplitudes in December; while, in the northern one, the semi-annual variations with maximum at the equinoxes are stronger than that in the southern one. Herein, owing to the high-resolution tidal data (one day), we could research the short term (day-to-day) variations of the SE2 tide. We found that: (1) the day-to-day variations manifests mainly at the altitudes range between 100 and 110 km; (2) it increases gradually with latitudes and it is stronger at the low-mid latitudes; (3) it is relatively slightly stronger around solstices than equinoxes; (4) it does not present a remarkably inter-annual variation. Finally, the SE2 day-to-day variations may be composed by the absolute amplitudes' variance and the impact of the wave phases. In addition, the variations of

  7. Master Agreement between Northern Michigan University Board of Control and American Association of University Professors, Northern Michigan Chapter, June 30, 1987-June 30 1990.

    ERIC Educational Resources Information Center

    American Association of Univ. Professors, Washington, DC.

    The collective bargaining agreement between Northern Michigan University Board of Control and Northern Michigan University chapter of the American Association of University Professors covering the period June 30, 1987-June 30, 1990 is presented. Items covered in the agreement include: chapter recognition, nondiscrimination, access to information,…

  8. Marking guides for northern hardwoods under the selection system

    Treesearch

    Carl, Jr. Arbogast

    1957-01-01

    The preparation of these guides has been a joint undertaking of research and national forest administration. Reviews and suggestions of other members of the Station who are active in northern hardwood research were helpful, especially those from men working at the Upper Peninsula Research Center in Marquette, Mich., and the Northern Lakes Research Center in Wausau, Wis...

  9. Northern Helping Practitioners and the Phenomenon of Secondary Trauma

    ERIC Educational Resources Information Center

    O'Neill, Linda K.

    2010-01-01

    This article highlights a narrative inquiry study that considered the experience of and the effects on 8 northern helping practitioners (5 women, 3 men, ages 30-60) who have 7 to 40 years of experience in providing trauma support in isolated communities in northern BC and the Yukon. Using a three-phase narrative analysis, 10 categories provided a…

  10. Northern nursing practice in a primary health care setting.

    PubMed

    Vukic, Adele; Keddy, Barbara

    2002-12-01

    This paper explicates the nature of outpost nursing work, and/or the day-to-day realities of northern nursing practice in a primary health care setting in Canada. The study was carried out to systematically explore the work of nurses in an indigenous setting. Institutional ethnography, pioneered by Dorothy Smith was the methodology used to guide this research. The theoretical perspective of this methodology does not seek causes or links but intends to explicate visible practices. It is intended to explicate the social organization of specific discourses that inform work processes of nurses working in remote indigenous communities. The data originated from various sources including spending 2 weeks in a northern remote community shadowing experienced nurses, taking field notes and audio taping interviews with these nurses. One of the two researchers was a northern practice nurse for many years and has had taught in an outpost nursing programme. As part of the process, texts were obtained from the site as data to be incorporated in the analysis. The lived experiences have added to the analytical understanding of the work of nurses in remote areas. Data uncovered documentary practices inherent to the work setting which were then analysed along with the transcribed interviews and field notes derived from the on-site visit. Identifying disjuncture in the discourse of northern nursing and the lived experience of the nurses in this study was central to the research process. The results indicated that the social organization of northern community nursing work required a broad generalist knowledge base for decision making to work effectively within this primary health care setting. The nurse as 'other' and the invisibility of nurses' work of building a trusting relationship with the community is not reflected in the discourse of northern nursing. Trust cannot be quantified or measured yet it is fundamental to working effectively with the community. The nurses in this study

  11. Molecular analysis of FRIGIDA, a major determinant of natural variation in Arabidopsis flowering time.

    PubMed

    Johanson, U; West, J; Lister, C; Michaels, S; Amasino, R; Dean, C

    2000-10-13

    Vernalization, the acceleration of flowering by a long period of cold temperature, ensures that many plants overwinter vegetatively and flower in spring. In Arabidopsis, allelic variation at the FRIGIDA (FRI) locus is a major determinant of natural variation in flowering time. Dominant alleles of FRI confer late flowering, which is reversed to earliness by vernalization. We cloned FRI and analyzed the molecular basis of the allelic variation. Most of the early-flowering ecotypes analyzed carry FRI alleles containing one of two different deletions that disrupt the open reading frame. Loss-of-function mutations at FRI have thus provided the basis for the evolution of many early-flowering ecotypes.

  12. Vesta Partly Shadowed Northern Regions

    NASA Image and Video Library

    2012-06-01

    This image from NASA Dawn spacecraft shows a part of asteroid Vesta surface reasonably far north into the northern hemisphere which appears washed out because it has been stretched to make features visible that would otherwise be too dark to see.

  13. 75 FR 47259 - Northern New Mexico Resource Advisory Committee Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-05

    ... DEPARTMENT OF AGRICULTURE Forest Service Northern New Mexico Resource Advisory Committee Meeting AGENCY: Forest Service, USDA. ACTION: Notice of meeting. SUMMARY: The Northern New Mexico Resource Advisory Committee will meet in Albuquerque, New Mexico. The committee is meeting as authorized under the...

  14. 75 FR 29717 - Northern New Mexico Resource Advisory Committee Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-27

    ... DEPARTMENT OF AGRICULTURE Forest Service Northern New Mexico Resource Advisory Committee Meeting AGENCY: Forest Service, USDA. ACTION: Notice of meeting. SUMMARY: The Northern New Mexico Resource Advisory Committee will meet in Albuquerque, New Mexico. The committee is meeting as authorized under the...

  15. Validation of daily increments in otoliths of northern squawfish larvae

    USGS Publications Warehouse

    Wertheimer, R.H.; Barfoot, C.A.

    1998-01-01

    Otoliths from laboratory-reared northern squawfish, Ptychocheilus oregonensis, larvae were examined to determine the periodicity of increment deposition. Increment deposition began in both sagittae and lapilli after hatching. Reader counts indicated that increment formation was daily in sagittae of 1-29-day-old larvae. However, increment counts from lapilli were significantly less than the known ages of northern squawfish larvae, possibly because some increments were not detectable. Otolith readability and age agreement among readers were greatest for young (<11 days) northern squawfish larvae. This was primarily because a transitional zone of low-contrast material began forming in otoliths of 8-11-day-old larvae and persisted until approximately 20 days after hatching. Formation of the transition zone appeared to coincide with the onset of exogenous feeding and continued through yolk sac absorption. Our results indicate that aging wild-caught northern squawfish larvae using daily otolith increment counts is possible.

  16. Northern perspectives on medical elective tourism: a qualitative study.

    PubMed

    Coke, Sarah; Kuper, Ayelet; Richardson, Lisa; Cameron, Anita

    2016-01-01

    The Royal College of Physicians and Surgeons of Canada recognizes education to be necessary for doctors to provide culturally safe care. Communities in northern Canada have large populations of Aboriginal people and other marginalized groups. Our goal was to identify the elements of appropriate predeparture curricula for these medical trainees. We conducted our study in Kenora, Ontario. With the help of a core collaborative group and the support of the local Aboriginal Health Access Centre, we interviewed a purposive sample of community members about their interactions with trainees from southern Canada. Aboriginal and non-Aboriginal researchers with roots in northern and southern Canada brought perspectives to the inductive analysis. We conducted 17 semistructured interviews between February and March 2014. Participants felt that southern trainees were inadequately educated in northern politics, society and history. They identified 2 more themes: determinants of health affecting the local Aboriginal population, and provider and patient factors affecting delivery of culturally competent care. Participants also shared ideas on how best to implement this content into curricula. Providing culturally competent care to northern communities is a complex process requiring education. Using a collaborative method, we were able to delineate the experiences of members of a northern community and identify knowledge gaps of southern trainees travelling there. Our results provide a foundation for the content and structure of formal predeparture curricula to enable such trainees to provide culturally safe care.

  17. Northern perspectives on medical elective tourism: a qualitative study

    PubMed Central

    Coke, Sarah; Kuper, Ayelet; Richardson, Lisa; Cameron, Anita

    2016-01-01

    Background: The Royal College of Physicians and Surgeons of Canada recognizes education to be necessary for doctors to provide culturally safe care. Communities in northern Canada have large populations of Aboriginal people and other marginalized groups. Our goal was to identify the elements of appropriate predeparture curricula for these medical trainees. Methods: We conducted our study in Kenora, Ontario. With the help of a core collaborative group and the support of the local Aboriginal Health Access Centre, we interviewed a purposive sample of community members about their interactions with trainees from southern Canada. Aboriginal and non-Aboriginal researchers with roots in northern and southern Canada brought perspectives to the inductive analysis. Results: We conducted 17 semistructured interviews between February and March 2014. Participants felt that southern trainees were inadequately educated in northern politics, society and history. They identified 2 more themes: determinants of health affecting the local Aboriginal population, and provider and patient factors affecting delivery of culturally competent care. Participants also shared ideas on how best to implement this content into curricula. Interpretation: Providing culturally competent care to northern communities is a complex process requiring education. Using a collaborative method, we were able to delineate the experiences of members of a northern community and identify knowledge gaps of southern trainees travelling there. Our results provide a foundation for the content and structure of formal predeparture curricula to enable such trainees to provide culturally safe care. PMID:27398374

  18. Phylogeographic analysis of mitochondrial DNA in northern Asian populations.

    PubMed

    Derenko, Miroslava; Malyarchuk, Boris; Grzybowski, Tomasz; Denisova, Galina; Dambueva, Irina; Perkova, Maria; Dorzhu, Choduraa; Luzina, Faina; Lee, Hong Kyu; Vanecek, Tomas; Villems, Richard; Zakharov, Ilia

    2007-11-01

    To elucidate the human colonization process of northern Asia and human dispersals to the Americas, a diverse subset of 71 mitochondrial DNA (mtDNA) lineages was chosen for complete genome sequencing from the collection of 1,432 control-region sequences sampled from 18 autochthonous populations of northern, central, eastern, and southwestern Asia. On the basis of complete mtDNA sequencing, we have revised the classification of haplogroups A, D2, G1, M7, and I; identified six new subhaplogroups (I4, N1e, G1c, M7d, M7e, and J1b2a); and fully characterized haplogroups N1a and G1b, which were previously described only by the first hypervariable segment (HVS1) sequencing and coding-region restriction-fragment-length polymorphism analysis. Our findings indicate that the southern Siberian mtDNA pool harbors several lineages associated with the Late Upper Paleolithic and/or early Neolithic dispersals from both eastern Asia and southwestern Asia/southern Caucasus. Moreover, the phylogeography of the D2 lineages suggests that southern Siberia is likely to be a geographical source for the last postglacial maximum spread of this subhaplogroup to northern Siberia and that the expansion of the D2b branch occurred in Beringia ~7,000 years ago. In general, a detailed analysis of mtDNA gene pools of northern Asians provides the additional evidence to rule out the existence of a northern Asian route for the initial human colonization of Asia.

  19. Agreement between Board of Control, Northern Michigan University, and American Association of University Professors, Northern Michigan University Chapter, July 1, 1984-June 30, 1987.

    ERIC Educational Resources Information Center

    American Association of Univ. Professors, Washington, DC.

    The collective bargaining agreement between Northern Michigan University Board of Control and Northern Michigan University Chapter (280 members) of the American Association of University Professors (AAUP) covering the period July 1, 1984-June 30, 1987 is presented. Items covered in the agreement include: definitions and recognition of AAUP;…

  20. Comparative ability of northern pintails, gadwalls, and northern shovelers to metabolize foods

    USGS Publications Warehouse

    Miller, M.R.

    1984-01-01

    Feeding trials were used to compare the ability of northern pintails (Anas acuta), gadwalls (A. strepera), and northern shovelers (A. clypeata) to metabolize energy from a turkey starter ration, alfalfa pellets, and common barnyardgrass (Echinochloa crusgalli) seeds. No differences (P > 0.05) were detected among the three species for any of the three foods (kg body weight/day basis), for dry matter intake (DMI), body weight gain (BWG), apparent metabolizable energy (AME), or metabolized energy (MEE) on any given diet consumed in quantities large enough to promote body weight gain. The AME content of alfalfa was 57% less than the value for turkey starter and 50% less than for barnyardgrass seeds. All three species metabolized more energy and gained weight faster when fed turkey starter. Energy modeling may be facilitated if additional research verifies that all species of dabbling ducks have equal ability to obtain energy from foods available to them in the wild. Behavioral and morphological factors may be more important in defining feeding niches than digestive physiology, at least for the three duck species tested, at the time of year of the experiments, and within the limits of the quality of foods used.

  1. Calculating competition in thinned northern hardwoods.

    Treesearch

    Sharon A. Winsauer; James A. Mattson

    1992-01-01

    Describes four methods of calculating competition to individual trees and compares their effectiveness in explaining the 3-year growth response of northern hardwoods after various mechanized thinning practices.

  2. Statistical Analysis of Interchange Injection Events from Over a Decade of Cassini Data

    NASA Astrophysics Data System (ADS)

    Azari, A.; Jia, X.; Liemohn, M. W.; Sergis, N.; Thomsen, M. F.; Mitchell, D. G.; Rymer, A. M.; Paranicas, C.; Provan, G.; Ye, S.; Cowley, S. W. H.; Hospodarsky, G. B.; Vandegriff, J. D.; Kurth, W. S.

    2017-12-01

    The Cassini spacecraft has routinely observed interchange injection events with multiple instruments since arriving at Saturn in 2004. Interchange injection events are thought to initiate from a Rayleigh-Taylor like plasma instability sourced from Saturn's rapid rotation (period 10.8 hours) and dense plasma population outgassing primarily from Enceladus, and are the primary source of mass transport in the inner/middle magnetosphere. This dense plasma must be transported outward, and to conserve magnetic flux, inward moving flux tubes of low density, energetic (> keV) plasma from the outer reaches of the Saturnian system also occur. These inward-bound flux tubes are referred to as interchange injections. We will present a statistical evaluation of the occurrence rates of interchange injections at Saturn demonstrating seasonal dependence of interchange over the entirety of the Cassini mission's equatorial orbits between 2005 and 2016. We identify interchange events from CHarge Energy Mass Spectrometer (CHEMS) H+ data using a trained and tested automated algorithm. Our event identification compares well with manual identification and previous surveys of injections by L-shell and local time (Chen and Hill, 2008, Lai et al., 2016, Kennelly et al., 2013). We find that peak rates of interchange events occur between 7 - 9 Saturn radii, in agreement with previous surveys. We also evaluate interchange by preferred local time sector and season, splitting our events into pre-equinox, equinox, and post - equinox time periods. We determine that over all seasons, nightside occurrence dominated as compared to dayside, but the preferred dayside sector shifts from pre-noon during equinox, to post-noon during post-equinox. We will further investigate seasonal dependence by presenting occurrence organized by the phase systems derived based on Saturn kilometric radiation (SKR) and magnetic field perturbations (PPO).

  3. 77 FR 61595 - Northern Illinois Municipal Power; Notice of Filing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-10

    ... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. EL13-5-000] Northern Illinois Municipal Power; Notice of Filing October 2, 2012. Take notice that on October 1, 2012, Northern Illinois Municipal Power filed its Revised and Superseding Proposed Revenue Requirement for reactive supply...

  4. Two new species of Chiropterotriton (Caudata: Plethodontidae) from northern Mexico.

    PubMed

    Rovito, Sean M; Parra-Olea, Gabriela

    2015-11-24

    Species of the genus Chiropterotriton are distributed through much of northern and eastern Mexico. The genus has presented taxonomic difficulties, with a number of species waiting to be described. We describe two new species, Chiropterotriton cieloensis sp. nov. and Chiropterotriton infernalis sp. nov., from the Mexican state of Tamaulipas based on both molecular and morphological data. We present a phylogenetic hypothesis for the group, with emphasis on the taxa from northern Mexico, based on mitochondrial DNA, and discuss the other species of northern Mexico, especially the wider-ranging C. multidentatus, to which the new species were formerly assigned.

  5. Flow characteristics of rivers in northern Australia: Implications for development

    NASA Astrophysics Data System (ADS)

    Petheram, Cuan; McMahon, Thomas A.; Peel, Murray C.

    2008-07-01

    SummaryAnnual, monthly and daily streamflows from 99 unregulated rivers across northern Australia were analysed to assess the general surface water resources of the region and their implications for development. The potential for carry-over storages was assessed using the Gould-Dincer Gamma method, which utilises the mean, standard deviation, skewness and lag-one serial correlation coefficient of annual flows. Runs Analysis was used to describe the characteristics of drought in northern Australia and the potential for 'active' water harvesting was evaluated by Base Flow Separation, Flow Duration Curves and Spells Analysis. These parameters for northern Australia were compared with data from southern Australia and data for similar Köppen class from around the world. Notably, the variability and seasonality of annual streamflow across northern Australia were observed to be high compared with that of similar Köppen classes from the rest of the world (RoW). The high inter-annual variability of runoff means that carry-over storages in northern Australia will need to be considerably larger than for rivers from the RoW (assuming similar mean annual runoff, yield and reliability). For example, in the three major Köppen zones across the North, it was possible (theoretically) to only exploit approximately 33% (Köppen Aw; n = 6), 25% (Köppen BSh; n = 12) and 13% (Köppen BWh; n = 11) of mean annual streamflow (assuming a hypothetical storage size equal to the mean annual flow). Over 90% of north Australian rivers had a Base Flow Index of less than 0.4, 72% had negative annual lag-one autocorrelation values and in half the rivers sampled greater than 80% of the total flow occurred during the 3-month peak period. These data confirm that flow in the rivers of northern Australia is largely event driven and that the north Australian environment has limited natural storage capacity. Hence, there is relatively little opportunity in many northern rivers to actively harvest water

  6. Cultivating Uncultured Bacteria from Northern Wetlands: Knowledge Gained and Remaining Gaps

    PubMed Central

    Dedysh, Svetlana N.

    2011-01-01

    Northern wetlands play a key role in the global carbon budget, particularly in the budgets of the greenhouse gas methane. These ecosystems also determine the hydrology of northern rivers and represent one of the largest reservoirs of fresh water in the Northern Hemisphere. Sphagnum-dominated peat bogs and fens are the most extensive types of northern wetlands. In comparison to many other terrestrial ecosystems, the bacterial diversity in Sphagnum-dominated wetlands remains largely unexplored. As demonstrated by cultivation-independent studies, a large proportion of the indigenous microbial communities in these acidic, cold, nutrient-poor, and water-saturated environments is composed of as-yet-uncultivated bacteria with unknown physiologies. Most of them are slow-growing, oligotrophic microorganisms that are difficult to isolate and to manipulate in the laboratory. Yet, significant breakthroughs in cultivation of these elusive organisms have been made during the last decade. This article describes the major prerequisites for successful cultivation of peat-inhabiting microbes, gives an overview of the currently captured bacterial diversity from northern wetlands and discusses the unique characteristics of the newly discovered organisms. PMID:21954394

  7. Visual impairment in Northern Ireland.

    PubMed Central

    Canavan, Y. M.; Jackson, A. J.; Stewart, A.

    1997-01-01

    Statistics on the registration of blind and partially-sighted patients in Northern Ireland underestimate the true extent of visual impairment within our community. In comparison to other UK regions, where between 0.53% and 0.59% of the population avail of blind or partial sight registration, only 0.35% of residents in Northern Ireland appear on the respective registers. Most patients on the combined registers are in the older age groups and many also suffer from other disabilities. Regional discrepancies may be attributed to a combination of factors including: patient attitudes to the registration process, medical attitudes to registration and local anomalies in the way in which social services departments both record and present annual registration returns. Better liaison is necessary between the community, hospital and voluntary sector providers to improve identification and support services for the visually impaired in the future. PMID:9414937

  8. The Impact of Insects in the Northern Hardwoods Type

    Treesearch

    H. J. Macaloney

    1966-01-01

    The northern hardwoods type occupies about 16 percent -- 8.2 million acres -- of the commercial forest land in the Lake States. The timber has high unit values and represents about 42 percent of the total value of all the commercial forest in the region. Increasing values and markets for northern hardwoods in recent years have stressed the need for better quality in...

  9. Suicide and Young People: The Case of Northern Ireland

    ERIC Educational Resources Information Center

    Tomlinson, Mike

    2007-01-01

    Suicides in Northern Ireland are examined in the context of what is known about global and regional trends with respect to gender and age, and change over time. For Northern Ireland, suicide numbers and rates are plotted for 10-24 year olds from 1967 to 2005. Questions are raised about the validity of officially registered suicides in the light of…

  10. Is the northern Saw-whet Owl (Aegolius acadicus) nomadic?

    Treesearch

    Jeffery S. Marks

    1997-01-01

    The first recorded nesting of a Northern Saw-whet Owl (Aegolius acadicus) in the Snake River Birds of Prey Area in southwestern Idaho occurred in a nest box in 1986. Occupancy of nest boxes by Northern Saw-whet Owls varied considerably (0 to 8 nests per year) over the next 10 years. Numbers of rodents fluctuated during this same period, and the...

  11. Rural telemedicine project in northern New Mexico

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Zink, S.; Hahn, H.; Rudnick, J.

    A virtual electronic medical record system is being deployed over the Internet with security in northern New Mexico using TeleMed, a multimedia medical records management system that uses CORBA-based client-server technology and distributed database architecture. The goal of the NNM Rural Telemedicine Project is to implement TeleMed into fifteen rural clinics and two hospitals within a 25,000 square mile area of northern New Mexico. Evaluation of the project consists of three components: job task analysis, audit of immunized children, and time motion studies. Preliminary results of the evaluation components are presented.

  12. Coastal geomorphology of the Martian northern plains

    NASA Technical Reports Server (NTRS)

    Parker, Timothy J.; Gorsline, Donn S.; Saunders, Stephen R.; Pieri, David C.; Schneeberger, Dale M.

    1993-01-01

    The paper considers the question of the formation of the outflow channels and valley networks discovered on the Martian northern plains during the Mariner 9 mission. Parker and Saunders (1987) and Parker et al. (1987, 1989) data are used to describe key features common both in the lower reaches of the outflow channels and within and along the margins of the entire northern plains. It is suggested, that of the geological processes capable of producing similar morphologies on earth, lacustrine or marine deposition and subsequent periglacial modification offer the simplest and most consistent explanation for the suit of features found on Mars.

  13. Comparative reproductive and physiological responses of northern bobwhite and scaled quail to water deprivation

    USGS Publications Warehouse

    Giuliano, W.M.; Patino, R.; Lutz, R.S.

    1998-01-01

    We compared reproductive and physiological responses of captive female northern bobwhite (Colinus virginianus) and scaled quail (Callipepla squamata) under control and water deprivation conditions. Scaled quail required less food and water to reproduce successfully under control conditions than northern bobwhite. Additionally, in scaled quail, serum osmolality levels and kidney mass were unaffected by water deprivation, whereas in northern bobwhite, serum osmolality levels increased and kidney mass declined. This finding indicates that scaled quail may have osmoregulatory abilities superior to those of northern bobwhite. Under control conditions, northern bobwhite gained more body mass and produced more but smaller eggs than scaled quail. Under water deprivation conditions, northern bobwhite lost more body mass but had more laying hens with a higher rate of egg production than scaled quail. Our data suggest that northern bobwhite allocated more resources to reproduction than to body maintenance, while scaled quail apparently forego reproduction in favor of body maintenance during water deprivation conditions.

  14. 40 CFR 81.100 - Eastern Washington-Northern Idaho Interstate Air Quality Control Region.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 17 2010-07-01 2010-07-01 false Eastern Washington-Northern Idaho... Designation of Air Quality Control Regions § 81.100 Eastern Washington-Northern Idaho Interstate Air Quality Control Region. The Eastern Washington-Northern Idaho Interstate Air Quality Control Region consists of...

  15. Fishing for Northern Pike in Minnesota: A comparison of anglers and dark house spearers

    USGS Publications Warehouse

    Schroeder, Susan A.; Fulton, David C.

    2014-01-01

    In order to project fishing effort and demand of individuals targeting Northern Pike Esox lucius in Minnesota, it is important to understand the catch orientations, management preferences, and site choice preferences of those individuals. Northern Pike are specifically targeted by about 35% of the approximately 1.5 million licensed anglers in Minnesota and by approximately 14,000–15,000 dark house spearers. Dark house spearing is a traditional method of harvesting fish through the ice in winter. Mail surveys were distributed to three research strata: anglers targeting Northern Pike, dark house spearing license holders spearing Northern Pike, and dark house spearing license holders angling for Northern Pike. Dark house spearers, whether spearing or angling, reported a stronger orientation toward keeping Northern Pike than did anglers. Anglers reported a stronger orientation toward catching large Northern Pike than did dark house spearers when spearing or angling. Northern Pike regulations were the most important attribute affecting site choice for respondents in all three strata. Models for all strata indicated a preference for lakes without protected slot limits. However, protected slot limits had a stronger negative influence on lake preference for dark house spearing licensees (whether spearing or angling) than for anglers.

  16. The Northern Manitoba Mining Academy

    NASA Astrophysics Data System (ADS)

    Alexandre, Paul

    2017-04-01

    The Northern Manitoba Mining Academy (NMMA, miningacademy.ca) is a new educational institution located in Flin Flon, Manitoba. It is associated with the University College of the North and is specifically intended to serve the needs of the Northern Manitoban communities with regards to job creation by providing training in a variety of mining, construction, and exploration related areas. NMMA's mission is to provide innovative and responsible solutions for the creation of a knowledgeable, skilled, and sustainable workforce within a vibrant, mineral-rich resource industry. It facilitates strategic training initiatives and research activities in order to strengthen the social, economic, and environmental benefits of a robust mining and resources sector. In terms of education, NMMA offers its own programs, mostly short courses in health and safety, courses organized by the University College of the North (wilderness safety, prospecting, and exploration), and courses organized in association with provincial Industries-Based Safety Programs and Associations (a variety of construction-related trades). However, the programming is not limited to those courses already on the syllabus: the Academy operates on open-doors policy and welcomes people with their unique and diverse needs; it prides itself in its ability to tailor or create specific on-demand courses and deliver them locally in the North. The Northern Manitoba Mining Academy also provides access to its world-class facilities for field-based undergraduate courses, as well as graduate students and researchers doing field work. Full sample preparation facilities are offered to students and scientists in all natural and environmental sciences.

  17. Workshop on the Martian Northern Plains: Sedimentological, Periglacial, and Paleoclimatic Evolution

    NASA Technical Reports Server (NTRS)

    Kargel, Jeffrey S. (Editor); Moore, Jeffrey (Editor); Parker, Timothy (Editor)

    1993-01-01

    Papers that have been accepted for presentation at the Workshop on the Martian Northern Plains: Sedimentological, Periglacial, and Paleoclimatic Evolution, on 12-14 Aug. 1993 in Fairbanks, Alaska are included. Topics covered include: hydrological consequences of ponded water on Mars; morphological and morphometric studies of impact craters in the Northern Plains of Mars; a wet-geology and cold-climate Mars model: punctuation of a slow dynamics approach to equilibrium; the distribution of ground ice on Mars; and stratigraphy of the Martian Northern Plains.

  18. Seasonal Variation of High-latitude Geomagnetic Activity Revisited

    NASA Astrophysics Data System (ADS)

    Tanskanen, E.; Hynönen, R.; Mursula, K.

    2017-12-01

    The coupling of the solar wind and auroral region has been examined by using westward electrojet indices since 1966 - 2014. We have studied the seasonal variation of high-latitude geomagnetic activity in individual years for solar cycles 20 - 24. The classical two-equinox activity pattern in geomagnetic activity was seen in multi-year averages but it was found in less than one third of the years examined. We found that the seasonal variation of high-latitude geomagnetic activity closely follows the solar wind speed. While the mechanisms leading to the two-equinox maxima pattern are in operation, the long-term change of solar wind speed tends to mask the effect of these mechanisms for individual years. We identified the most active and the second most active season based on westward electrojet indices AL (1966 - 2014) and IL (1995 - 2014). The annual maximum is found at either equinox in 2/3 and at either solstice in 1/3 of the years examined. Large cycle-to-cycle variation is found in the seasonal pattern: equinox maxima are more common during cycles 21 and 22 than in cycles 23 or 24. An exceptionally long winter dominance in high-latitude activity and solar wind speed is seen in the declining phase of cycle 23, after the appearance of the long-lasting low-latitude coronal hole.

  19. 78 FR 51716 - Northern Natural Gas Company; Notice of Application

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-21

    ... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. CP13-528-000] Northern Natural Gas Company; Notice of Application Take notice that on August 1, 2013, Northern Natural Gas... section 7(c) of the Natural Gas Act and part 157 of the Commission's regulations to construct and operate...

  20. Education Policy Reforms of Secondary Education in the Northern Territory

    ERIC Educational Resources Information Center

    Palmer, Bill

    2004-01-01

    An original study of the Ramsay Committee report entitled "Future Directions for Secondary Education in the Northern Territory" (the "Secondary Review") was presented in December 2004 at the ANZCIES National Conference in Melbourne. This was prior to the Northern Territory Government deciding how many of the recommendations of…

  1. Phylogeographic Analysis of Mitochondrial DNA in Northern Asian Populations

    PubMed Central

    Derenko, Miroslava ; Malyarchuk, Boris ; Grzybowski, Tomasz ; Denisova, Galina ; Dambueva, Irina ; Perkova, Maria ; Dorzhu, Choduraa ; Luzina, Faina ; Lee, Hong Kyu ; Vanecek, Tomas ; Villems, Richard ; Zakharov, Ilia 

    2007-01-01

    To elucidate the human colonization process of northern Asia and human dispersals to the Americas, a diverse subset of 71 mitochondrial DNA (mtDNA) lineages was chosen for complete genome sequencing from the collection of 1,432 control-region sequences sampled from 18 autochthonous populations of northern, central, eastern, and southwestern Asia. On the basis of complete mtDNA sequencing, we have revised the classification of haplogroups A, D2, G1, M7, and I; identified six new subhaplogroups (I4, N1e, G1c, M7d, M7e, and J1b2a); and fully characterized haplogroups N1a and G1b, which were previously described only by the first hypervariable segment (HVS1) sequencing and coding-region restriction-fragment–length polymorphism analysis. Our findings indicate that the southern Siberian mtDNA pool harbors several lineages associated with the Late Upper Paleolithic and/or early Neolithic dispersals from both eastern Asia and southwestern Asia/southern Caucasus. Moreover, the phylogeography of the D2 lineages suggests that southern Siberia is likely to be a geographical source for the last postglacial maximum spread of this subhaplogroup to northern Siberia and that the expansion of the D2b branch occurred in Beringia ∼7,000 years ago. In general, a detailed analysis of mtDNA gene pools of northern Asians provides the additional evidence to rule out the existence of a northern Asian route for the initial human colonization of Asia. PMID:17924343

  2. Global Distributions of Ionospheric Electrostatic Potentials for Various Interplanetary Conditions

    NASA Astrophysics Data System (ADS)

    Kartalev, M.; Papitashvili, V.; Keremidarska, V.; Grigorov, K.; Romanov, D.

    2001-12-01

    We report on a study of the global ionospheric electrostatic potential distributions obtained from combining two algorithms used for the mapping of high-latitude and middle-latitude ionospheric electrodynamics; that is, the LiMIE (http://www.sprl.umich.edu/mist/) and IMEH (http://geospace.nat.bg) models, respectively. In this combination, the latter model utilizes the LiMIE high-latitude field-aligned current distributions for various IMF conditions and different seasons (summer, winter, equinox). The IMEH model is a mathematical tool, allowing us to study conjugacy (or non-conjugacy) of the ionospheric electric fields on a global scale, from the northern and southern polar regions to the middle- and low-latitudes. The proposed numerical scheme permits testing of different mechanisms of the interhemispheric coupling and mapping to the ionosphere through the appropriate current systems. The scheme is convenient for determining self-consistently the separatrices in both the northern and southern hemispheres. In this study we focus on the global ionospheric electrostatic field distributions neglecting other possible electric field sources. Considering some implications of the proposed technique for the space weather specification and forecasting, we developed a Web-based interface providing global distributions of the ionospheric electrostatic potentials in near-real time from the ACE upstream solar wind observations at L1.

  3. 77 FR 35958 - Northern Natural Gas Company; Notice of Application

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-15

    ... Natural Gas Company; Notice of Application Take notice that on May 30, 2012, Northern Natural Gas Company... authority, pursuant to Part 157 of the Commission's regulations and section 7(b) of the Natural Gas Act, to... public inspection. Specifically, Northern Natural Proposes to sell to DKM approximately 126 miles of 24...

  4. 75 FR 35779 - Northern Natural Gas Company; Notice of Application

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-23

    ... Natural Gas Company; Notice of Application June 16, 2010. Take notice that on June 2, 2010, Northern Natural Gas Company (Northern), 1111 South 103rd Street, Omaha, Nebraska 68124, filed with the Federal Energy Regulatory Commission an application under section 7 of the Natural Gas Act, for a certificate of...

  5. ACHP | Heritage Tourism and the Federal Government: Northern New Mexico

    Science.gov Websites

    Publications Search skip specific nav links Home arrow Publications arrow Intro: Heritage Tourism and the Federal Government: Northern New Mexico Perspectives Heritage Tourism and the Federal Government: Northern information Heritage tourism offers a triple benefit to communities—it promotes the preservation of their

  6. Food habits of Northern Goshawks nesting in south central Wyoming

    Treesearch

    John R. Squires

    2000-01-01

    Northern Goshawks (Accipiter gentiles) nesting in south central Wyoming consumed at least 33 species of prey; 14 were mammals and 19 were birds. Based on percent occurrence in regurgitated pellets, dominant (>10% frequency) prey species included: red squirrel (Tamiasciurus hudsonicus; present in 50% of pellets), Northern Flicker (Colaptes auratus; 34...

  7. 50 CFR 226.203 - Critical habitat for northern right whales.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 10 2014-10-01 2014-10-01 false Critical habitat for northern right whales. 226.203 Section 226.203 Wildlife and Fisheries NATIONAL MARINE FISHERIES SERVICE, NATIONAL... § 226.203 Critical habitat for northern right whales. (a) Great South Channel. The area bounded by 41°40...

  8. 50 CFR 226.203 - Critical habitat for northern right whales.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 50 Wildlife and Fisheries 10 2012-10-01 2012-10-01 false Critical habitat for northern right whales. 226.203 Section 226.203 Wildlife and Fisheries NATIONAL MARINE FISHERIES SERVICE, NATIONAL... § 226.203 Critical habitat for northern right whales. (a) Great South Channel. The area bounded by 41°40...

  9. 50 CFR 226.203 - Critical habitat for northern right whales.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 10 2013-10-01 2013-10-01 false Critical habitat for northern right whales. 226.203 Section 226.203 Wildlife and Fisheries NATIONAL MARINE FISHERIES SERVICE, NATIONAL... § 226.203 Critical habitat for northern right whales. (a) Great South Channel. The area bounded by 41°40...

  10. Northern hemisphere dust storms on Mars

    NASA Technical Reports Server (NTRS)

    James, P. B.

    1993-01-01

    Dust storms in the northern hemisphere of Mars appear to be less common than the more familiar southern hemisphere storms, and essentially, no activity north of about 30 latittude has been documented. The data are, however, subject to an observational bias because Mars is near aphelion during oppositions, which occur during the most likely seasons for dust activity in the north. The amount of dust activity in the northern hemisphere is clearly very relevant to the role of atmospheric transport in the dust cycle. The classic global storms that occur during spring in the southern hemisphere are observed to transport dust from sources in the southern hemisphere to sinks or temporary depositories in the north. The question of whether atmospheric transport can close the dust cycle, i.e., return the dust to the southern hemisphere sources on some timescale, is clearly relevant to the solution of the puzzle of how the dust storm cycle is modulated, i.e., why storms occur in some years but not in others. There are data that suggest that the spring/early summer season in the northern hemisphere of Mars during the year following the major 1977 storms observed by Viking was very dusty. A number of observations of the vicinity of the receding north polar cap showed clear evidence of substantial dust activity in the sub-Arctic region.

  11. Pace slows in northern Rockies

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Stremel, K.

    1984-03-01

    This paper deals with recent natural gas development and production in the northern Rocky Mountain region. Because of restricted gas markets, the pace has slowed construction of gas processing and gathering facilities. The gas and oil companies which are planning or building new projects are discussed.

  12. Transferring climate research results to stakeholder needs in Northern Germany

    NASA Astrophysics Data System (ADS)

    Meinke, Insa

    2013-04-01

    The North German Climate Office was established in 2006 at the Institute for Coastal Research at the Helmholtz-Zentrum Geesthacht, Germany as consequence of an increased public information need regarding coastal climate change and its impacts in Northern Germany. The service is characterized by an intensive dialogue between regional climate research and stakeholders in Northern Germany. About once a week scientists of the North German climate office are invited to contribute to public dialogue events. Also, numerous direct inquiries are answered and expert interviews are conducted. From this dialogue process specific stakeholder information needs are localized and analysed to develop tailored information products. To provide easy and user specific access to research results interactive web tools are developed. One example is the North German climate atlas, an interactive web tool on possible future climate change in Northern Germany. Another interactive web tool is informing on present and future coastal protection needs in Northern Germany. Another aim of our information products is to assess and summarize the existing scientific knowledge on climate, climate change and impacts in Northern Germany. A mini IPCC-like regional assessment report has been published in 2010, which is summarizing, discussing and assessing the scientific knowledge on regional climate, climate change and impacts as well as possible adaptation strategies in the metropolitan region of Hamburg.

  13. Structure and deformation history of the northern range of Trinidad and adjacent areas

    NASA Astrophysics Data System (ADS)

    Algar, S. T.; Pindell, J. L.

    1993-08-01

    Conflicting models have been proposed for both the evolution of northern South America and the neotectonics of the south Caribbean plate boundary zone. The Trinidadian portion of the margin is particularly controversial, but surprisingly it has been little studied. We present a structural analysis of Trinidad's Northern Range, pertinent updates of the island's stratigraphy and sedimentology, and new zircon fission track age determinations, and use them to constrain Trinidad's geologic history, and to better understand the controlling tectonic processes. In our interpretation Trinidad's three E-ENE striking ranges, which are separated by late Neogene-Recent depocenters, expose (1) the Northern Range Group, generally greenschist-metamorphosed Upper Jurassic to Cretaceous north facing continental slope sediments of the Northern Range, deposited on the northern South American passive margin 200-400 km to the WNW, and (2) the Trinidad Group, Cretaceous-Paleogene shelf slope sediments of the central and southern Trinidad deposited less than 100 km WNW of their present location. A small allochthon composing the Sans Souci Group Cretaceous tholeiitic volcaniclastic, basaltic, and gabbroic rocks (Sans Souci Formation) and sediments (Toco Formation) now in the northeastern Northern Range, has been transported hundreds of kilometers from the west with the Caribbean Plate. Despite earlier references to Cretaceous orogenesis, all deformation in Trinidad is of Cenozoic age. The first deformation in the Northern Range (D1) formed north vergent nappes and induced greenschist metamorphism, probably in the Late Eocene or Oligocene. The nappes developed either by the underthrusting of the Proto-Caribbean crust beneath South America due to convergence between North and South America, or as gravity slides caused by oversteepening induced by this convergence and/or the passage of the Caribbean Plate's peripheral bulge and arrival of its foredeep. Northern Range D2 deformation is south

  14. Wildfires in Northern Siberian Larch Dominated Communities

    NASA Technical Reports Server (NTRS)

    Khaurk, Viacheslav I.; Ranson, Kenneth J.; Dvinskaya, Maria L.; Im, Sergey T.

    2011-01-01

    The fire history of the northern larch forests within the permafrost zone in a portion of northern Siberia (approx 66 deg N, 100 deg E) was studied. Since there is little to no human activities in this area fires within the study area were mostly caused by lightning. Fire return intervals (FRI) were estimated based on burn marks on tree stems and dates of tree natality. FRI values varied from 130 yr to 350 yr with 200 +/- 50 yr mean. In southerly larch dominated communities FRI was found to be shorter (77 +/- 20 yr at approx 61 deg. N, and 82 +/- 7 at 64 deg N), and longer at the northern boundary (approx 71 deg) of larch stands (320 +/- 50 yr). During the Little Ice Age period in the 16th to 18th centuries FRI was approximately twice as long as recorded in this study. Fire caused changes in the soil including increases in soil drainage and permafrost thawing depth and a radial growth increase of about 2 times (with more than 6 times observed). This effect may simulate the predicted warming impact on the larch growth in the permafrost zone.

  15. Mechanical suppression of northern pike (Esox lucius) populations in small Arizona reservoirs

    USGS Publications Warehouse

    Kuzmenko, Yuliya; Spesiviy, Timofy; Bonar, Scott A.

    2010-01-01

    Introduced populations of northern pike Esox lucius have provided angling opportunities in the western United States (McMahon and Bennett 1996). However, the northern pike is a voracious piscivore and its large size, high fecundity, and broad physiological tolerance make it capable of drastically altering ecosystems it invades (Marchetti et al. 2004). Indeed, predation by northern pike has been shown to significantly alter fish community structure and put native fishes at a higher extinction risk (He and Kitchell 1990, Findlay et al. 2000). Predation by northern pike is viewed as a significant threat to native stocks of salmonids in Washington, British Columbia, and California (McMahon and Bennett 1996, California Department of Fish and Game [CDFG] 2003).

  16. Hypolactasia in the indigenous populations of northern Russia.

    PubMed

    Kozlov, A I

    1998-01-01

    The distribution of hypolactasia (PH) in the indigenous populations of the polar and related territories of the Russian Federation was investigated by an oral lactose tolerance. The frequency of hypolactasia in Kildin Saami population is 48%, Komi-Izhem-63%, Northern Mansi-71%, Northern Khanty-72%, West Siberia Nenets-78%. Generally hypolactasia frequencies in indigenous groups of Arctic and Sub-Arctic territories of Russia are higher than in the "reference" samples of Slav (Russian, 40-49%) and Permian Finn (Komi-Permiak and Udmurtian, 50-59%) groups.

  17. Juvenile movement and natal dispersal on northern goshawks in Arizona

    Treesearch

    J. David Wiens; Richard T. Reynolds; Barry R. Noon

    2006-01-01

    We investigated the departure, transient movement, and local settlement stages of natal dispersal in a population of Northern Goshawks (Accipiter gentilis) on the Kaibab Plateau of northern Arizona. The study included 614 color-banded juveniles produced at 555 nests during 1991-2003, 89 of which were radio-marked during 1998-2001. Radio-marked...

  18. Drinking and Smoking Habits of Students at Northern Territory University.

    ERIC Educational Resources Information Center

    Roberts, Kathryn L.; Jackson, Adrian S.

    Persons in the Northern Territory who drink have the highest per capita daily consumption of alcohol and the highest rate of tobacco smoking in Australia. This study identifies the drinking patterns and demographic and personal variables that might predict risk levels for Northern Territory University (NTU) students and therefore give direction to…

  19. 76 FR 12721 - Northern Natural Gas Company; Notice of Application

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-08

    ... Natural Gas Company; Notice of Application Take notice that on February 18, 2011, Northern Natural Gas... application pursuant to section 7(b) of the Natural Gas Act (NGA) and Part 157 of the Commission's regulations..., Northern Natural Gas Company, P.O. Box 3330, Omaha, Nebraska 68103-0330, or by calling (402) 398-7103...

  20. Northern goshawk habitat: an intersection of science, management, and conservation

    Treesearch

    Richard T. Reynolds; Russell T. Graham; Douglas A. Boyce

    2008-01-01

    We responded to the claim by Greenwald et al. (2005) that the management recommendations for the northern goshawk in the Southwestern United States (MRNG; Reynolds et al. 1992), a food web-based conservation plan that incorporated both northern goshawk (Accipiter gentilis) and multiple prey habitats, may be inadequate to protect goshawks. Greenwald...

  1. Ecology and social system of northern gibbons living in cold seasonal forests.

    PubMed

    Guan, Zhen-Hua; Ma, Chang-Yong; Fei, Han-Lan; Huang, Bei; Ning, Wen-He; Ni, Qing-Yong; Jiang, Xue-Long; Fan, Peng-Fei

    2018-07-18

    Gibbons in China represent the northernmost margin of present day gibbon species distribution (around N25°). Compared to tropical habitats, northern gibbon habitats are characterized by low temperatures and remarkable seasonal variation in fruit abundance. How gibbons adapt to their cold and seasonal habitats and what ecological factors affect their sociality are key questions for understanding their ecology and social system evolution, the elucidation of which will contribute to the conservation of these special populations/species. According to preliminary short-term studies, northern gibbons consume more leaves and use larger home ranges than tropical gibbons. Interestingly, some Nomascus groups consist of more than one adult female. However, these preliminary results are not well understood or incorporated into current socio-ecological theories regarding gibbon species. To better understand northern gibbons, our team has systematically studied three habituated groups of Nomascus concolor, three groups of N. nasutus, and two habituated groups of Hoolock tianxing since 2002. In this paper, we stress the challenges facing gibbons living in northern habitats and summarize their behavioral adaptations to their harsh environments. We also describe the northern gibbon social system and discuss the potential relationships between their ecology and sociality. Finally, we highlight future research questions related to northern gibbons in China.

  2. Multiple Landslide-Hazard Scenarios Modeled for the Oakland-Berkeley Area, Northern California

    USGS Publications Warehouse

    Pike, Richard J.; Graymer, Russell W.

    2008-01-01

    With the exception of Los Angeles, perhaps no urban area in the United States is more at risk from landsliding, triggered by either precipitation or earthquake, than the San Francisco Bay region of northern California. By January each year, seasonal winter storms usually bring moisture levels of San Francisco Bay region hillsides to the point of saturation, after which additional heavy rainfall may induce landslides of various types and levels of severity. In addition, movement at any time along one of several active faults in the area may generate an earthquake large enough to trigger landslides. The danger to life and property rises each year as local populations continue to expand and more hillsides are graded for development of residential housing and its supporting infrastructure. The chapters in the text consist of: *Introduction by Russell W. Graymer *Chapter 1 Rainfall Thresholds for Landslide Activity, San Francisco Bay Region, Northern California by Raymond C. Wilson *Chapter 2 Susceptibility to Deep-Seated Landsliding Modeled for the Oakland-Berkeley Area, Northern California by Richard J. Pike and Steven Sobieszczyk *Chapter 3 Susceptibility to Shallow Landsliding Modeled for the Oakland-Berkeley Area, Northern California by Kevin M. Schmidt and Steven Sobieszczyk *Chapter 4 Landslide Hazard Modeled for the Cities of Oakland, Piedmont, and Berkeley, Northern California, from a M=7.1 Scenario Earthquake on the Hayward Fault Zone by Scott B. Miles and David K. Keefer *Chapter 5 Synthesis of Landslide-Hazard Scenarios Modeled for the Oakland-Berkeley Area, Northern California by Richard J. Pike The plates consist of: *Plate 1 Susceptibility to Deep-Seated Landsliding Modeled for the Oakland-Berkeley Area, Northern California by Richard J. Pike, Russell W. Graymer, Sebastian Roberts, Naomi B. Kalman, and Steven Sobieszczyk *Plate 2 Susceptibility to Shallow Landsliding Modeled for the Oakland-Berkeley Area, Northern California by Kevin M. Schmidt and Steven

  3. Habitat use and movement patterns of Northern Pintails during spring in northern Japan: the importance of agricultural lands

    USGS Publications Warehouse

    Yamaguchi, Noriyuki M.; Hupp, Jerry W.; Flint, Paul L.; Pearce, John M.; Shigeta, Yusuke; Shimada, Tetsuo; Hiraoka, Emiko N.; Higuchi, Hiroyoshi

    2012-01-01

    From 2006 to 2009, we marked 198 Northern Pintails (Anas acuta) with satellite transmitters on their wintering areas in Japan to study their migration routes and habitat use in spring staging areas. We hypothesized that the distribution of pintails during spring staging was influenced by patterns of land use and expected that the most frequently used areas would have more agricultural habitat than lesser-used areas. We obtained 3031 daily locations from 163 migrant pintails marked with satellite transmitters and identified 524 stopover sites. Based on a fixed kernel home range analysis of stopover utilization distribution (UD), core staging areas (areas within the 50% UD) were identified in northern Honshu and western Hokkaido, and were used by 71% of marked pintails. Core staging areas had a greater proportion of rice fields than peripheral (51–95% UD) and rarely used (outside the 95% UD) staging areas. Stopover sites also contained more rice fields and other agricultural land than were available at regional scales, indicating that pintails selected rice and other agricultural habitats at regional and local scales. Pintails remained at spring staging areas an average of 51 d. Prolonged staging in agricultural habitats of northern Japan was likely necessary for pintails to prepare for transoceanic migration to Arctic nesting areas in eastern Russia.

  4. GIA induced intraplate seismicity in northern Central Europe

    NASA Astrophysics Data System (ADS)

    Brandes, Christian; Steffen, Holger; Steffen, Rebekka; Wu, Patrick

    2015-04-01

    Though northern Central Europe is regarded as a low seismicity area (Leydecker and Kopera, 1999), several historic earthquakes with intensities of up to VII affected the area in the last 1200 years (Leydecker, 2011). The trigger for these seismic events is not sufficiently investigated yet. Based on the combination of historic earthquake epicentres with the most recent fault maps we show that the historic seismicity concentrated at major reverse faults. There is no evidence for significant historic earthquakes along normal faults in northern Central Europe. The spatial and temporal distribution of earthquakes (clusters that shift from time to time) implies that northern Central Europe behaves like a typical intraplate tectonic region as demonstrated for other intraplate settings (Liu et al., 2000) We utilized Finite Element models that describe the process of glacial isostatic adjustment to analyse the fault behaviour. We use the change in Coulomb Failure Stress (dCFS) to represent the minimum stress required to reach faulting. A negative dCFS value indicates that the fault is stable, while a positive value means that GIA stress is potentially available to induce faulting or cause fault instability or failure unless released temporarily by an earthquake. The results imply that many faults in Central Europe are postglacial faults, though they developed outside the glaciated area. This is supported by the characteristics of the dCFS graphs, which indicate the likelihood that an earthquake is related to GIA. Almost all graphs show a change from negative to positive values during the deglaciation phase. This observation sheds new light on the distribution of post-glacial faults in general. Based on field data and the numerical simulations we developed the first consistent model that can explain the occurrence of deglaciation seismicity and more recent historic earthquakes in northern Central Europe. Based on our model, the historic seismicity in northern Central Europe

  5. Jupiter's Northern Lights

    NASA Image and Video Library

    2017-09-06

    This is a reconstructed view of Jupiter's northern lights through the filters of Juno's Ultraviolet Imaging Spectrometer (UVS) instrument on Dec. 11, 2016, as the Juno spacecraft approached Jupiter, passed over its poles, and plunged towards the equator. Such measurements present a real challenge for the spacecraft's science instruments: Juno flies over Jupiter's poles at 30 miles (50 kilometers) per second -- more than 100,000 miles per hour -- speeding past auroral forms in a matter of seconds. https://photojournal.jpl.nasa.gov/catalog/PIA21938

  6. Generic names of northern and southern fur seals (Mammalia: Otariidae)

    USGS Publications Warehouse

    Gardner, A.L.; Robbins, C.B.

    1998-01-01

    We have resolved a nomenclatural problem discovered during research on the northern fur seal that concerns the correct generic name for this taxon and for fur seals of the Southern Hemisphere. The unfortunate practice by some 19th century authors to use names in their Latinized form, but to date them from their first appearance as French common names led to the use of Arctocephalus for southern fur seals when the name correctly applies to the northern fur seal, known today as Callorhinus ursinus. However, Arctocephalus and Callorhinus are antedated by Otoes G. Fischer, 1817, which is the earliest available generic for the fur seal of the northern Pacific. The earliest available generic name for southern fur seals is Halarctus Gill, 1866. To avoid the confusion that would result from replacing the currently used generic names with those required by strict adherence to the Principle of Priority, we have petitioned the International Commission on Zoological nomenclature to preserve Arctocephalus and Callorhinus for the southern and northern fur seals, respectively.

  7. Exploration of a New World: Saturn's Moon Titan

    NASA Astrophysics Data System (ADS)

    Hansen, Candice; Ray, Trina; Matson, Dennis L.; Lebreton, Jean-Pierre; Waite, J. Hunter; Turtle, Elizabeth; Bolton, Scott; Spilker, Linda

    waiting to be filled in by higher resolution imaging and radar swaths during the Equinox mission. Is there a liquid layer in Titan's interior? A few more gravity passes and radar swaths are needed to answer this question. To-date no interior magnetic field has been detected, so a very close Titan flyby is planned at the end of the Equinox mission to go below the ionosphere. Titan's atmosphere has weather that can be compared to earth. Clouds form. Rain falls. The over-arching goal for the Cassini Solstice mission would be to observe changes: seasonal certainly, and any other surface activity. Will the current northern lakes dry up and new southern ones form? With the luxury of time and numerous flybys the Cassini / Huygens mission is slowly revealing a complex, new world. Copyright 2008 California Institute of Technology. Government sponsorship acknowledged.

  8. MGS Mars Orbiter Laser (MOLA) Surface Topography of Northern Hemisphere

    NASA Technical Reports Server (NTRS)

    1997-01-01

    A 'picket fence' rendition of surface topography in the northern hemisphere of Mars from the Mars Orbiter Laser Altimeter (MOLA). The profile was obtained during the Mars Global Surveyor Capture Orbit Calibration Pass on September 15, 1997. The profile runs from 73oN to 10oS latitude and passes through the topographically subdued northern plains, the western part of the Elysium volcanic province, which shows 3 miles (5 kilometers) of relief, and the chaotic 'dichotomy' boundary between the northern plains and ancient southern highlands. The MOLA profile is approximately 3000 miles (5000 kilometers) long and has a resolution on the surface of 1000 feet (330 meters) and a vertical resolution of approximately 3 feet (1 meter).

  9. Spatio-temporal characteristics of the Equatorial Ionization Anomaly (EIA) in the East African region via ionospheric tomography during the year 2012

    NASA Astrophysics Data System (ADS)

    Kassa, T.; Damtie, B.; Bires, A.; Yizengaw, E.; Cilliers, P.

    2015-01-01

    We present the characteristics of the EIA in the East African sector inferred from ground-based GPS receivers via ionospheric tomography during the year 2012. For the analysis, we developed and used a 2D ionospheric tomography imaging software based on Bayesian inversion approach. To reconstruct ionospheric electron density form slant Total Electron Content (sTEC) measurements, we selected a chain of ten ground-based GPS receivers with stations' codes and geomagnetic coordinates: ARMI (3.03 °S, 109.29 °E), DEBK (4.32 °N, 109.48 °E), ASOS (1.14 °N, 106.16 °E), NEGE (3.60 °S, 111.35 °E), SHIS (3.26 °N, 110.62 °E), ASAB (4.91 °N, 114.34 °E), SHEB (7.36 °N, 110.60 °E), EBBE (9.54 °S, 104.10 °E), DODM (16.03 °S, 109.04 °E) & NAMA (11.49 °N, 113.60 °E). The temporal, spatial and storm-time characteristics of the EIA and the hourly, day-to-day and seasonal variations of the maximum electron density of F2 region (NmF2) at 15.29°S geomagnetic latitude are presented. We found that the magnitude of the peak and the width/thickness of the EIA pronounced during the equinox and weakened during the solstice seasons at 2100 LT. It is also observed that the EIA persisted for longer time in equinox season than the solstice season. The spatial appearance of the northern and southern anomalies are observed starting from 6.12 ° N and 10 ° S respectively along geomagnetic latitude during equinox season. The EIA is localized between 180 km and 450 km along the altitude during December solstice. The analysis on the NmF2 demonstrated a significant dependence on local time, day and season of the year. We also investigated the storm response of the EIA for the magnetic storm of Day Of the Year (DOY) 274-276. It is observed that the disturbance dynamo related composition change (O/N2 ratio) resulted in a well-developed EIA with an increase in the peak and the width of the EIA at 2100 LT on DOY 275 (main phase of the storm) compared to 274 (initial phase of the storm

  10. The outlook for northern forests

    Treesearch

    Stephen R. Shifley; W. Keith Moser; Sherri Wormstead; Francisco X. Aguilar

    2016-01-01

    The forests of the Northern United States have been remarkably resilient to nearly four centuries of immigration and settlement with associated anthropogenic disturbances caused by farming, logging, burning, urbanization, trade, and many other factors. Although resilient, forests conditions have been significantly impacted by humans as is illustrated by the extent of...

  11. Sampling considerations for demographic and habitat studies of Northern Goshawks

    Treesearch

    Richard T. Reynolds; J. David Wiens; Suzanne M. Joy; Susan R. Salafsky

    2005-01-01

    We used mark-recapture methods to monitor Northern Goshawks (Accipiter gentilis) and their nests over 12 yr in an increasing sample of breeding territories (37 in 1991 to 121 in 2002) in northern Arizona. As many as 8 yr of repeated nest searching were required to identify the population of breeders, as individuals skipped egg-laying on territories...

  12. 50 CFR 226.203 - Critical habitat for northern right whales.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 50 Wildlife and Fisheries 9 2011-10-01 2011-10-01 false Critical habitat for northern right whales. 226.203 Section 226.203 Wildlife and Fisheries NATIONAL MARINE FISHERIES SERVICE, NATIONAL OCEANIC AND... Critical habitat for northern right whales. (a) Great South Channel. The area bounded by 41°40′ N/69°45′ W...

  13. LEECHES (ANNELIDA: EUHIRUDINEA) OF NORTHERN ARKANSAS

    EPA Science Inventory

    Twenty-one lotic and lentic environments throughout central and northern Arkansas were surveyed for the presence of leeches during June 2004, and April, July - October, 2005. Fourteen species of leeches (Desserobdella cryptobranchii, Desserobdella phalera, Desserobdella picta, H...

  14. 76 FR 63910 - Intent To Prepare a Draft Environmental Impact Statement for the Proposed Excelsior Estates...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-14

    ... (Branchinecta lynchi), vernal pool tadpole shrimp (Lepidurus packardi), Sacramento Orcutt grass (Orcuttia viscida) and slender Orcutt grass (Orcuttia tenuis). The EIS will include alternatives to the Proposed...

  15. 40 CFR 81.116 - Northern Missouri Intrastate Air Quality Control Region.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Quality Control Region. 81.116 Section 81.116 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Air Quality Control Regions § 81.116 Northern Missouri Intrastate Air Quality Control Region. The Northern Missouri Intrastate Air Quality Control Region consists of the territorial area encompassed by the...

  16. 40 CFR 81.116 - Northern Missouri Intrastate Air Quality Control Region.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Quality Control Region. 81.116 Section 81.116 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Air Quality Control Regions § 81.116 Northern Missouri Intrastate Air Quality Control Region. The Northern Missouri Intrastate Air Quality Control Region consists of the territorial area encompassed by the...

  17. Genetics Show Current Decline and Pleistocene Expansion in Northern Spotted Owls

    USGS Publications Warehouse

    Funk, W. Chris; Forsman, Eric D.; Mullins, Thomas D.; Haig, Susan M.

    2008-01-01

    The northern spotted owl (Strix occidentalis caurina) is one of the most controversial threatened subspecies ever listed under the U.S. Endangered Species Act. Because of concern for persistence of the subspecies, logging on Federal lands in the U.S. Pacific Northwest was dramatically reduced under the Northwest Forest Plan in 1994. Despite protection of its remaining forest habitat, recent field studies show continued demographic declines of northern spotted owls. One potential threat to northern spotted owls that has not yet been shown is loss of genetic variation from population bottlenecks that can increase inbreeding depression and decrease adaptive potential. Here, we show recent genetic bottlenecks in northern spotted owls using a large genetic dataset (352 individuals from across the subspecies' range and 11 microsatellite loci). The signature of bottlenecks was strongest in Washington State, in agreement with field data. Interestingly, we also found a genetic signature of Pleistocene expansion in the same study areas where recent bottlenecks were shown. Our results provide independent evidence that northern spotted owls have recently declined, and suggest that loss of genetic variation is an emerging threat to the subspecies' persistence. Reduced effective population size (Ne), shown here in addition to field evidence for demographic decline, highlights the increasing vulnerability of this bird to extinction.

  18. The timing and extent of Quaternary glaciation of Stok, northern Zanskar Range, Transhimalaya, of northern India

    NASA Astrophysics Data System (ADS)

    Orr, Elizabeth N.; Owen, Lewis A.; Murari, Madhav K.; Saha, Sourav; Caffee, Marc W.

    2017-05-01

    The glacial history of three tributary valleys (Namlung, Gopal Kangri and Stok Kangri) of the Stok valley, south of the Indus valley in the northern sector of the Zanskar Range, northern India is characterized using geomorphic mapping and cosmogenic 10Be surface exposure dating. The new glacial chronostratigraphy for the Stok valley is the first for the northern Zanskar Range and provides insights into the spatial variability of glaciation in the Himalayan-Tibetan orogen. This framework facilitates the understanding of the nature and the timing of landscape evolution and paleoenvironmental change in the Himalayan-Tibetan orogen. At least four glacial stages are evident within each of the tributary valleys of Gopal Kangri (MG1-MG4, youngest to oldest) and Stok Kangri (MS1-MS4) that feed into the Stok valley. With the exception of the MG4 glacial advance ( 124 ka) in Gopal Kangri, the Stok valley has preserved evidence of glaciations from 50 ka to the present. Equilibrium-line altitudes and glacier reconstructions for the Stok valley and its tributaries demonstrate that glaciations have become progressively less extensive through time. Former glacier extents of the Stok region are comparable in length with glacial advances during the last glacial cycle in eastern Zanskar and in the southern Ladakh Range to the south and north of the Indus valley, respectively. Landscape evolution in the study area has occurred across numerous glacial-interglacial cycles by a combination of glacial and fluvial processes and is similar to that of the Ladakh Range.

  19. Anisotropic Rayleigh-wave phase velocities beneath northern Vietnam

    NASA Astrophysics Data System (ADS)

    Legendre, Cédric P.; Zhao, Li; Huang, Win-Gee; Huang, Bor-Shouh

    2015-02-01

    We explore the Rayleigh-wave phase-velocity structure beneath northern Vietnam over a broad period range of 5 to 250 s. We use the two-stations technique to derive the dispersion curves from the waveforms of 798 teleseismic events recoded by a set of 23 broadband seismic stations deployed in northern Vietnam. These dispersion curves are then inverted for both isotropic and azimuthally anisotropic Rayleigh-wave phase-velocity maps in the frequency range of 10 to 50 s. Main findings include a crustal expression of the Red River Shear Zone and the Song Ma Fault. Northern Vietnam displays a northeast/southwest dichotomy in the lithosphere with fast velocities beneath the South China Block and slow velocities beneath the Simao Block and between the Red River Fault and the Song Da Fault. The anisotropy in the region is relatively simple, with a high amplitude and fast directions parallel to the Red River Shear Zone in the western part. In the eastern part, the amplitudes are generally smaller and the fast axis displays more variations with periods.

  20. February 2003 marine atmospheric conditions and the bora over the northern Adriatic

    USGS Publications Warehouse

    Dorman, C.E.; Carniel, S.; Cavaleri, L.; Sclavo, M.; Chiggiato, J.; Doyle, J.; Haack, T.; Pullen, J.; Grbec, B.; Vilibic, I.; Janekovic, I.; Lee, C.; Malacic, V.; Orlic, M.; Paschini, E.; Russo, A.; Signell, R.P.

    2007-01-01

    A winter oceanographic field experiment provided an opportunity to examine the atmospheric marine conditions over the northern Adriatic. Mean February winds are from a northeasterly direction over most of the Adriatic and a more northerly direction along the western coast. Wind speeds are fastest in jets over the NE coast during bora events and weakest in the mid-northwestern Adriatic. Diurnal air temperature cycles are smallest on the NE coast and largest in the midwestern Adriatic. The maximum sea-air difference is +10??C on the eastern coast and near zero on the midwestern Adriatic. Boras are northeasterly (from) wind events that sweep off Croatia and Slovenia, bringing slightly colder and drier air over the northern Adriatic. The main bora season is December to March. Winter 2002-2003 was normal for bora events. Synoptic-scale temporal variations are correlated over the northern Adriatic. Fastest Bora winds and highest wind stress over the northern Adriatic is concentrated in four topographically controlled jets. The strongest is the Senj Jet, while the Trieste Jet extends across the entire northern Adriatic. Between each two jets is a weak wind zone. The greatest mean net heat loss is in bora jets in the NE Adriatic, where it was -438 W m-2 and is weakest in the midwestern northern Adriatic, where it was near zero. Wind stress is concentrated over the NE half of Adriatic in four bora jets, while wind stress is weak in the NW Adriatic. There is significant variation in wind stress mean and standard deviation structure over the northern Adriatic with each bora event. Copyright 2006 by the American Geophysical Union.

  1. High Rates of Staphylococcus aureus USA400 Infection, Northern Canada

    PubMed Central

    Golding, George R.; Levett, Paul N.; McDonald, Ryan R.; Irvine, James; Quinn, Brian; Nsungu, Mandiangu; Woods, Shirley; Khan, Mohammad; Ofner-Agostini, Marianna

    2011-01-01

    Surveillance of Staphylococcus aureus infections in 3 northern remote communities of Saskatchewan was undertaken. Rates of methicillin-resistant infections were extremely high (146–482/10,000 population), and most (98.2%) were caused by USA400 strains. Although USA400 prevalence has diminished in the United States, this strain is continuing to predominate throughout many northern communities in Canada. PMID:21470471

  2. Sea-floor gouges caused by migrating gray whales off northern California

    USGS Publications Warehouse

    Cacchione, D.A.; Drake, D.E.; Field, M.E.; Tate, G.B.

    1987-01-01

    Side-scan sonar records collected during March and April 1981 and 1982 off northern California contain elongate depressions whose sizes and shapes are similar to sea-floor gouges made by feeding gray whales (Eschrichtius robustus) in the northern Bering Sea and in shallow embayments off British Columbia. The discovery of the whale gouges in the sonar records was unexpected, and supports some of the previous speculation that gray whales feed opportunistically during migration. Gouges occupy about 0.032% of the 7.6 km2 of sea floor that was surveyed, which represents about 575 metric tons of excavated material. Although seemingly minor in amount, the total amount of bottom sediment removed from the central and northern California continental shelf by gray whale activities year after year represents macroscale biologically induced erosion and could have significant geological implications in shelf erosion and depositional schemes. This is the only published evidence of benthic feeding by gray whales along their migration route off northern California. ?? 1987.

  3. An alternative method for processing northern blots after capillary transfer.

    PubMed

    Nilsen, Timothy W

    2015-03-02

    Different laboratories use different methods for the prehybridization, hybridization, and washing steps of the northern blotting procedure. In this protocol, a northern blot is pretreated with Church and Gilbert hybridization buffer to block nonspecific probe-binding sites. The immobilized RNA is then hybridized to a DNA probe specific for the RNA of interest. Finally, the membrane is washed and subjected to autoradiography or phosphorimaging. The solutions and conditions described here may be ideal for those who prefer to use fewer ingredients in their solutions. This protocol is designed to achieve the same goals as other northern blotting approaches. It minimizes background (nonspecific adherence of probe to membrane and nonspecific hybridization) and maximizes specific hybridization to RNAs immobilized on a membrane. © 2015 Cold Spring Harbor Laboratory Press.

  4. 78 FR 54658 - Allergenic Products Advisory Committee; Notice of Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-05

    ... Vernal Grass, Perennial Ryegrass, Timothy Grass, Orchard Grass, and Kentucky Bluegrass Mixed Pollens... Grastek, a Timothy Grass Pollen Allergen Extract tablet for sublingual use, manufactured by Merck. FDA...

  5. Flood of April and May 2008 in Northern Maine

    USGS Publications Warehouse

    Lombard, Pamela J.

    2010-01-01

    Severe flooding occurred in Aroostook and Penobscot Counties in northern Maine between April 28 and May 1, 2008, and was most extreme in the town of Fort Kent. Peak streamflows in northern Aroostook County were the result of a persistent heavy snowpack that caused high streamflows when it quickly melted during the third week of April 2008. Snowmelt was followed by from two to four inches of rainfall over a 2-day period in northern Maine. Peak water-surface elevations resulting from the flood were obtained from 13 continuous-record streamgages and 63 surveyed high-water marks in Aroostook and Penobscot Counties. Peak streamflows were obtained from 20 sites on 15 streams through stage/discharge rating curves or hydraulic flow models. Peak water-surface elevations and streamflows were the highest ever recorded at seven continuous-record streamgages, which had between 25 and 84 years of record in northern Aroostook County. The annual exceedance probability (the percent chance of exceeding the streamflow recorded during the April/May 2008 flood during any given year) at six streamgages in northern Maine was equal to or less than 1 percent. Data from flood-insurance studies published by the Federal Emergency Management Agency were available for five of the locations analyzed for the April/May 2008 flood and were compared to streamflows and observed peak water-surface elevations from the 2008 flood. Water-surface elevations that would be expected given the observed flow as applied to the effective flood insurance studies ranged from between 1 and 4 feet from the water-surface elevations observed during the 2008 flood. Differences were likely the result of up to 30 years of additional data for the calculation of recurrence intervals and the fact that hydraulic models used for the models had not previously been calibrated to a flood of this magnitude.

  6. Strip cutting in northern hardwoods

    Treesearch

    Richard M. Godman

    1992-01-01

    Interest in clearcutting young northern hardwood stands in strips is running high, especially now that mechanical fellers and skidders have been developed to harvest these stands. Strip cutting has several advantages-no overstory to worry about when treating the site, no overstory to remove later, and the economic advantage of cutting the strip only once.

  7. Development of northern red oak rooted cutting and enrichment planting systems

    Treesearch

    Matthew H. Gocke; Jamie Schuler; Daniel J. Robison; Barry Goldfarb

    2005-01-01

    Enrichment planting may provide an efficient means to establish elite northern red oak (Quercus rubra L.) genotypes in recently harvested natural forests. However, planting northern red oak (NRO) seedlings into natural stands has proven difficult in the past, especially when competition and other stress factors are not controlled.

  8. Visual Grading and Quality of 1-0 Northern Red Oak Seedlings

    Treesearch

    S.L. Clark; S.E. Scblarbaum; Paul P. Kormanik

    2000-01-01

    Past research has used detailed measurements of various growth characteristics to determine seedling grades and quality of northern red oak nursery stock This study evaluates the effectiveness ofa visual grading process. similar to thosefound in commercial nursery operations, to distinguish high quality seedlings. Northern red oak (Quercus rubra...

  9. Groundwater management in northern Iraq

    NASA Astrophysics Data System (ADS)

    Stevanovic, Zoran; Iurkiewicz, Adrian

    2009-03-01

    Groundwater is vital and the sole resource in most of the studied region of northern Iraq. It has a significant role in agriculture, water supply and health, and the elimination of poverty in rural areas. Although Iraq is currently dramatically disturbed by complex political and socio-economic problems, in its northern part, i.e. the Kurdish-inhabited region, fast urbanization and economic expansion are visible everywhere. Monitoring and water management schemes are necessary to prevent aquifer over-exploitation in the region. Artificial recharge with temporary runoff water, construction of subsurface dams and several other aquifer management and regulation measures have been designed, and some implemented, in order to improve the water situation. Recommendations, presented to the local professionals and decision-makers in water management, include creation of Water Master Plans and Water User Associations, synchronization of drilling programmes, rehabilitation of the existing well fields, opening of new well fields, and the incorporation of new spring intakes in some areas with large groundwater reserves, as well as construction of numerous small-scale schemes for initial in situ water treatment where saline groundwater is present.

  10. Low-latitude thermospheric neutral winds determined from AE-E measurements of the 6300-A nightglow at solar maximum

    NASA Technical Reports Server (NTRS)

    Burrage, M. D.; Abreu, V. J.; Fesen, C. G.

    1990-01-01

    Atmosphere Explorer E (AE-E) measurements of the O(1D) 6300-A emission in the nighttime equatorial thermosphere are used to infer the height of the F2 layer peak as a function of latitude and local time. The investigation is conducted both for northern hemisphere winter solstice and for spring equinox, under solar maximum conditions. The layer heights are used to derive magnetic meridional components of the transequatorial neutral wind, in conjunction with the MSIS-86 model and previous Jicamarca incoherent scatter measurements of the zonal electric field. The AE-E wind estimates indicate a predominant summer to winter flow for the winter solstice case. Comparisons are made with the empirical horizontal wind model HWM87 and with winds generated by the thermospheric general circulation model. The model predictions and experimental results are generally in good agreement, confirming the applicability of visible airglow data to studies of the global neutral wind pattern.

  11. Short Shadow

    NASA Image and Video Library

    2017-05-15

    The projection of Saturn's shadow on the rings grows shorter as Saturn's season advances toward northern summer, thanks to the planet's permanent tilt as it orbits the sun. This will continue until Saturn's solstice in May 2017. At that point in time, the shadow will extend only as far as the innermost A ring, leaving the middle and outer A ring completely free of the planet's shadow. Over the course of NASA's Cassini mission, the shadow of Saturn first lengthened steadily until equinox in August 2009. Since then, the shadow has been shrinking. This view looks toward the sunlit side of the rings from about 10 degrees above the ring plane. The image was taken in visible light with the Cassini spacecraft wide-angle camera on Feb. 3, 2017. The view was acquired at a distance of approximately 760,000 miles (1.2 million kilometers) from Saturn. Image scale is 46 miles (73 kilometers) per pixel. https://photojournal.jpl.nasa.gov/catalog/PIA21328

  12. Y chromosomal evidence on the origin of northern Thai people.

    PubMed

    Brunelli, Andrea; Kampuansai, Jatupol; Seielstad, Mark; Lomthaisong, Khemika; Kangwanpong, Daoroong; Ghirotto, Silvia; Kutanan, Wibhu

    2017-01-01

    The Khon Mueang represent the major group of people present in today's northern Thailand. While linguistic and genetic data seem to support a shared ancestry between Khon Mueang and other Tai-Kadai speaking people, the possibility of an admixed origin with contribution from local Mon-Khmer population could not be ruled out. Previous studies conducted on northern Thai people did not provide a definitive answer and, in addition, have largely overlooked the distribution of paternal lineages in the area. In this work we aim to provide a comprehensive analysis of Y paternal lineages in northern Thailand and to explicitly model the origin of the Khon Mueang population. We obtained and analysed new Y chromosomal haplogroup data from more than 500 northern Thai individuals including Khon Mueang, Mon-Khmer and Tai-Kadai. We also explicitly simulated different demographic scenarios, developed to explain the Khon Mueang origin, employing an ABC simulation framework on both mitochondrial and Y microsatellites data. Our results highlighted a similar haplogroup composition of Khon Mueang and Tai-Kadai populations in northern Thailand, with shared high frequencies of haplogroups O-PK4, O-M117 and O-M111. Our ABC simulations also favoured a model in which the ancestors of modern Khon Mueang originated recently after a split from the other Tai-Kadai populations. Our different analyses concluded that the ancestors of Khon Mueang are likely to have originated from the same source of the other Tai-Kadai groups in southern China, with subsequent admixture events involving native Mon-Khmer speakers restricted to some specific populations.

  13. The Evolution of Northern Hemisphere Glaciation

    NASA Astrophysics Data System (ADS)

    Wright, J. D.

    2001-05-01

    For much of the last 50 million years, high-latitude regions remained too warm to allow snow to accumulate and form ice sheets. Shackleton et al. (1984) published a landmark paper correlating the first occurrence of ice-rafted detritus (IRD) observed at Rockall Plateau with a prominent increase in benthic foraminiferal d18O values during the late Pliocene. These late Pliocene to Pleistocene ice sheets were modulated on an orbital frequency and have characterized the global climate over the past 2.6 myr (Shackleton and Opdyke, 1973; Shackleton et al., 1984; Ruddiman, et al., 1986). During the early Pliocene, northern hemisphere glaciation (NHG) variations were less significant (Jansen et al., 1993). Our understanding of the Plio-Pleistocene ice sheet cycles can be viewed from two different perspectives. When viewed from the late Pleistocene, the fundamental question is what changed near the early/late Pliocene boundary to produce the large-scale, glacial-interglacial cycles of the past 2.6 Ma. In contrast, the view from the middle to late Miocene is quite different. Since the pioneering work of Shackleton et al. (1984), the record of NHG has been extended further back in time with drilling in the Norwegian Sea (ODP Leg 104). At Sites 642 and 644, IRD was found throughout the late Miocene and back to ~12 Ma. More recent drilling in the high northern latitudes occurred on ODP Leg 151. Site 909 recovered a middle Miocene section from the Fram Straits with rounded quartz grains that were interpreted as IRD (Wolf-Welling et al., 1996). Age estimates for those sediments place the first northern hemisphere ice sheets at least as old as 14 Ma. The occurrence of sand-sized particles (>1000 μm) and coal below this level indicates the possibility of glacial activity in the Northern Hemisphere as early as 16 Ma. Thus, the late Pliocene to Pleistocene cycles appear to be the resumption of the glacial-interglacial pattern that began during the Miocene. While the Miocene ice

  14. Ten Years after Patten: Young People and Policing in Northern Ireland

    ERIC Educational Resources Information Center

    Byrne, Jonny; Jarman, Neil

    2011-01-01

    Through a comprehensive review of existing literature, this article documents young people's experiences of policing during the period of political transition and extensive reform of the structures of policing in Northern Ireland since the publication of the Independent Commission on Policing for Northern Ireland (The Patten Report) in 1999. The…

  15. 75 FR 44789 - Northern Natural Gas Company; Notice of Technical Conference

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-29

    ... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. RP10-841-000] Northern Natural Gas Company; Notice of Technical Conference July 20, 2010. By order dated July 9, 2010 \\1\\ the... discussed in the July 9, 2010 Order. \\1\\ Northern Natural Gas Company, 132 FERC ] 61,021 (2010). FERC...

  16. Lightning and forest fires in the northern Rocky Mountain region

    Treesearch

    H. T. Gisborne

    1926-01-01

    During the past 18 years lightning has caused 39 per cent of the forest fires in the northern Rocky Mountain district, which includes Montana, northern Idaho, and a small portion of northeastern Washington. For the seasons of 1924 and 1925 the figures are 51 per cent and 80 per cent, respectively. As long as such conditions prevail it should be of decided value to know...

  17. The Enigma of Mercury's Northern Rise

    NASA Astrophysics Data System (ADS)

    James, P. B.

    2018-05-01

    Various aspects of the "northern rise" make it hard to explain: Its composition and chronology don't stand out from its surroundings, it seems to have uplifted late, and it has a huge gravity anomaly. We'll discuss the possible formation mechanisms.

  18. Plate tectonics of the northern part of the Pacific Ocean

    NASA Astrophysics Data System (ADS)

    Verzhbitsky, E. V.; Kononov, M. V.; Kotelkin, V. D.

    2007-10-01

    Geophysical data on the northern part of the Pacific Ocean were systematized to compile a map of geomagnetic and geothermal studies of the Bering Sea. The absence of reliable data about the formation time of the Bering Sea structures of oceanic and continental origins is noted; this hampered the assessment of the geodynamical processes in the North Pacific. Based on the geophysical data, we estimated the age of the structures of the Bering Sea floor such as the Commander Basin (21 My), the Shirshov Ridge (95 and 33 My in the northern and southern parts, respectively), the Aleutian Basin (70 My), the Vitus Arch (44 My), the Bowers Ridge (30 My), and the Bowers Basin (40 My). These values are confirmed by the geological, geophysical, and kinematic data. A numerical modeling of the formation of extensive regional structures (Emperor Fracture Zone, Chinook Trough, and others) in the Northern Pacific is carried out. A conclusion was made on the basis of the geological and geothermal analysis that the northern and southern parts of the Shirshov Ridge have different geological ages and different tectonic structures. The northern part of the ridge is characterized by an upthrust-nappe terrain origin, while the southern part has originated from a torn-away island arc similar to the origin of the Bowers Ridge. The sea floor of the Aleutian Basin represents a detached part of the Upper Cretaceous Kula plate, on which spreading processes took place in the Vitus Arch area in the Eocene. The final activity phase in the Bering Sea began 21 My B.P. by spreading of the ancient oceanic floor of the Commander Basin. Based on the age estimations of the structures of the Bering Sea floor, the results of the modeling of the process of formation of regional fracture zones and of the geomagnetic, geothermal, tectonic, geological, and structural data, we calculated and compiled a kinematic model (with respect to a hot spot reference system) of the northern part of the Pacific Ocean for 21

  19. Reproduction and microhabitat selection in a sharply declining Northern Bobwhite population

    USGS Publications Warehouse

    Collins, B.M.; Williams, C.K.; Castelli, Paul M.

    2009-01-01

    Northern Bobwhite (Colinus virginianus) populations have been declining throughout their range, but some of the sharpest declines have been documented in the Mid-Atlantic states. We conducted a 2 year (2006-2007) breeding season (1 May-30 Sep) telemetry study in southern New Jersey to collect baseline data on Northern Bobwhite reproductive rates, and nest and brood microhabitat selection. We located 23 Northern Bobwhite nests, of which 21 were usable for survival analyses. Incubation-period nest survival rate was 0.454 ?? 0.010 (95 CI =0.2800.727). Mean clutch size was 14.2 ?? 0.58 (range 10-19, n = 20) and hatching success was 96.1 ?? 2.0 (range 86-100%, n = 10). The estimated probability that an individual that entered the breeding season would initiate incubation of ???1 nest was 0.687 for females and 0.202 for males. Nest microhabitat selection was positively related to visual obstruction and percentage of litter. Brood microhabitat selection was positively related to visual obstruction, vegetation height, and percentage of forbs but negatively related to percentage of cool season grass and litter. Fecundity metrics for Northern Bobwhites in southern New Jersey appear similar to those reported elsewhere in the species' range. Conservation efforts to increase Northern Bobwhite reproductive success in southern New Jersey should focus on increasing the quantity of available breeding habitat. ?? 2009 by the Wilson Ornithological Society.

  20. Regional Climate Service in Northern Germany -The North German Climate Office

    NASA Astrophysics Data System (ADS)

    Meinke, I.; Von Storch, H.

    2012-12-01

    The North German Climate Office was established in 2006 at the Institute for Coastal Research at the Helmholtz-Zentrum Geesthacht, Germany as consequence of an increased public information need regarding coastal climate change and its impacts in Northern Germany. The service is characterized by an intensive dialogue between regional climate research and stakeholders in Northern Germany. About once a week scientists of the North German climate office are invited to contribute to public dialogue events. Also numerous direct inquiries are answered and expert interviews are conducted. From this dialogue process specific stakeholder information needs are localized and analysed to develop tailored information products. To provide easy and user specific access to research results interactive web tools are developed. One example is the North German climate atlas, an interactive web tool on possible future climate change in Northern Germany. Another interactive web tool is informing on present and future coastal protection needs in Northern Germany. Another aim of our information products is to assess and summarize the existing scientific knowledge on climate, climate change and impacts in Northern Germany. A mini IPCC-like regional assessment report has been published in 2010, which is summarizing, discussing and assessing the scientific knowledge on regional climate, climate change and impacts as well as possible adaptation strategies in the metropolitan region of Hamburg.

  1. Long-term variability in Northern Hemisphere snow cover and associations with warmer winters

    USGS Publications Warehouse

    McCabe, Gregory J.; Wolock, David M.

    2010-01-01

    A monthly snow accumulation and melt model is used with gridded monthly temperature and precipitation data for the Northern Hemisphere to generate time series of March snow-covered area (SCA) for the period 1905 through 2002. The time series of estimated SCA for March is verified by comparison with previously published time series of SCA for the Northern Hemisphere. The time series of estimated Northern Hemisphere March SCA shows a substantial decrease since about 1970, and this decrease corresponds to an increase in mean winter Northern Hemisphere temperature. The increase in winter temperature has caused a decrease in the fraction of precipitation that occurs as snow and an increase in snowmelt for some parts of the Northern Hemisphere, particularly the mid-latitudes, thus reducing snow packs and March SCA. In addition, the increase in winter temperature and the decreases in SCA appear to be associated with a contraction of the circumpolar vortex and a poleward movement of storm tracks, resulting in decreased precipitation (and snow) in the low- to mid-latitudes and an increase in precipitation (and snow) in high latitudes. If Northern Hemisphere winter temperatures continue to warm as they have since the 1970s, then March SCA will likely continue to decrease.

  2. Long-term variability in Northern Hemisphere snow cover and associations with warmer winters

    USGS Publications Warehouse

    McCabe, G.J.; Wolock, D.M.

    2010-01-01

    A monthly snow accumulation and melt model is used with gridded monthly temperature and precipitation data for the Northern Hemisphere to generate time series of March snow-covered area (SCA) for the period 1905 through 2002. The time series of estimated SCA for March is verified by comparison with previously published time series of SCA for the Northern Hemisphere. The time series of estimated Northern Hemisphere March SCA shows a substantial decrease since about 1970, and this decrease corresponds to an increase in mean winter Northern Hemisphere temperature. The increase in winter temperature has caused a decrease in the fraction of precipitation that occurs as snow and an increase in snowmelt for some parts of the Northern Hemisphere, particularly the mid-latitudes, thus reducing snow packs and March SCA. In addition, the increase in winter temperature and the decreases in SCA appear to be associated with a contraction of the circumpolar vortex and a poleward movement of storm tracks, resulting in decreased precipitation (and snow) in the low- to mid-latitudes and an increase in precipitation (and snow) in high latitudes. If Northern Hemisphere winter temperatures continue to warm as they have since the 1970s, then March SCA will likely continue to decrease. ?? 2009 Springer Science+Business Media B.V.

  3. Winter movements of four fish species near a thermal plume in northern Minnesota

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Ross, M.J.; Winter, J.D.

    1981-01-01

    During winter 1975, 17 yellow perch (Perca flavescens), 6 northern pike (Esox lucius), 3 walleyes (Stizostedion vitreum), and 2 largemouth bass (Micropterus salmoides) were equipped with radio frequency transmitters to compare their winter movements near the thermal plume of a power plant. The mean home range sizes, in hectares, were northern pike 19.0; yellow perch 13.4; largemouth bass 3.7; walleye 2.2. Northern pike and yellow perch had mean home range sizes larger than the discharge area. Mean water depths at fish locations were as follows: largemouth bass 0.8 m; northern pike 1.2 m; yellow perch 1.6 m; walleye 3.5 m.more » Largemouth bass preferred the warmest locations near the discharge point. Yellow perch were most often located in the peripheral areas of the discharge bay while walleyes were most often located in the deeper center area. Northern pike moved over the entire discharge area. All species except largemouth bass moved freely between discharge-affected and unaltered waters. The average numbers of movements per individual per week between heated and unheated areas were the following: northern pike 0.8; yellow perch 1.2; walleye 1.1; largemouth bass, 0.« less

  4. 78 FR 26064 - Endangered and Threatened Wildlife and Plants; Draft Conservation Strategy for the Northern...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-03

    ...] Endangered and Threatened Wildlife and Plants; Draft Conservation Strategy for the Northern Continental... availability of a draft Conservation Strategy for the Northern Continental Divide Ecosystem grizzly bear (Ursus.... ADDRESSES: An electronic copy of the draft Conservation Strategy for the Northern Continental Divide grizzly...

  5. Maturation and reproduction of northern flying squirrels in Pacific Northwest forests.

    Treesearch

    Lisa J. Villa; Andrew B. Carey; Todd M. Wilson; Karma E. Glos

    1999-01-01

    Northern flying squirrels are the primary prey of northern spotted owls and are important dispersers of fungal spores in Pacific Northwest forests. Despite the importance of these squirrels in forest ecosystems, information is lacking on life history and methods for determining age and reproductive condition. In the laboratory, we measured epiphyseal notch, femur...

  6. Vernal distribution and turnover of dimethylsulfide (DMS) in the surface water of the Yellow Sea

    NASA Astrophysics Data System (ADS)

    Li, Cheng-Xuan; Yang, Gui-Peng; Wang, Bao-Dong; Xu, Zong-Jun

    2016-10-01

    The spatial and interannual variations of dimethylsulfide (DMS) and its precursors, dissolved and particulate dimethylsulfoniopropionate (DMSP), were discussed on the basis of field observations in the surface waters of the Yellow Sea during spring 2007. Maxima of dimethylated sulfur compounds and low chlorophyll a concentrations were found in the central southern Yellow Sea, whereas low concentrations of DMS and DMSP were detected at the boundary between the northern and southern parts of the Yellow Sea. This frontal region is influenced by active water currents, air-sea interface exchanges, and biological turnover. The horizontal variations in DMS production and consumption rates showed a decreasing tendency from the coastal to offshore areas mainly due to the complicated biological features. DMS positively correlated with dissolved CH4 and CO2 but negatively correlated with nutrients (nitrite and phosphate). Particulate DMSP concentrations and DMS production rates positively correlated with dinoflagellate abundances but negatively correlated with diatom cell densities. DMS and DMSP concentrations, as well as DMS production and consumption rates, exhibited approximately 2.0-2.8 fold increases from 2005 to 2012. This finding was likely caused by shifts in the phytoplankton communities from diatoms to dinoflagellates and the increases in abundances of zooplankton and bacteria. Average sea-to-air DMS fluxes were estimated to be 8.12 ± 1.24 µmol·(m-2·d-1), and DMS microbial consumption was approximately 1.68 times faster than the DMS sea-air exchange. These findings imply that biological consumption, relative to ventilation, is a predominant mechanism in DMS removal from the surface water.

  7. Northern Eurasian Heat Waves and Droughts

    NASA Technical Reports Server (NTRS)

    Schubert, Siegfried; Wang, Hailan; Koster, Randal; Suarez, Max; Groisman, Pavel

    2013-01-01

    This article reviews our understanding of the characteristics and causes of northern Eurasian summertime heat waves and droughts. Additional insights into the nature of temperature and precipitation variability in Eurasia on monthly to decadal time scales and into the causes and predictability of the most extreme events are gained from the latest generation of reanalyses and from supplemental simulations with the NASA GEOS-5 AGCM. Key new results are: 1) the identification of the important role of summertime stationary Rossby waves in the development of the leading patterns of monthly Eurasian surface temperature and precipitation variability (including the development of extreme events such as the 2010 Russian heat wave), 2) an assessment of the mean temperature and precipitation changes that have occurred over northern Eurasia in the last three decades and their connections to decadal variability and global trends in SST, and 3) the quantification (via a case study) of the predictability of the most extreme simulated heat wave/drought events, with some focus on the role of soil moisture in the development and maintenance of such events. A literature survey indicates a general consensus that the future holds an enhanced probability of heat waves across northern Eurasia, while there is less agreement regarding future drought, reflecting a greater uncertainty in soil moisture and precipitation projections. Substantial uncertainties remain in our understanding of heat waves and drought, including the nature of the interactions between the short-term atmospheric variability associated with such extremes and the longer-term variability and trends associated with soil moisture feedbacks, SST anomalies, and an overall warming world.

  8. Growth, condition, diet, and consumption rates of northern pike in three Arizona reservoirs

    USGS Publications Warehouse

    Flinders, J.M.; Bonar, Scott A.

    2008-01-01

    Northern pike (Esox lucius L.) introductions are controversial in the western United States due to suspected impacts they might have on established sport fisheries and potential illegal introductions. Tbree Arizona reservoirs, Parker Canyon Lake, Upper Lake Mary and Long Lake were sampled to examine the diet, consumption dynamics, and growth of northern pike. Northern pike diets varied by season and reservoir. In Parker Canyon Lake, diets were dominated by rainbow trout in winter and spring and bluegill and green sunfish in the fall. In Long Lake the northern pike ate crayfish in spring and early summer and switched to young of the year common carp in summer and fall. Black crappie, golden shiners, and crayfish were the major prey in Upper Lake Mary during spring, but they switched to stocked rainbow trout in the fall. Northern pike growth was in the high range of growth reported throughout the United States. Estimated northern pike specific consumption rate (scr) of rainbow trout (g/g/d ?? 10-6) was greatest in Upper Lake Mary (scr = 329.1 ?? 23.7 g/g/d ?? 10-6) where stocked fingerling (280 mm TL) rainbow trout stocked in Long Lake (scr = 1.4 ?? 0.1 g/g/d ?? 10-6) and Parker Canyon Lake (scr = 287.2 ?? 15.1 g/g/d ?? 10-6) where catchable-sized rainbow trout were stocked. Managers should consider the cost-benefits of stocking fish >200 mm TL in lakes containing northern pike. ?? Copyright by the North American Lake Management Society 2008.

  9. Thailand low and equatorial F 2-layer peak electron density and comparison with IRI-2007 model

    NASA Astrophysics Data System (ADS)

    Wichaipanich, N.; Supnithi, P.; Tsugawa, T.; Maruyama, T.

    2012-06-01

    Ionosonde measurements obtained at two Thailand ionospheric stations, namely Chumphon (10.72°N, 99.37°E, dip 3.0°N) and Chiang Mai (18.76°N, 98.93°E, dip 12.7°N) are used to examine the variation of the F 2-layer peak electron density ( N m F 2) which is derived from the F 2-layer critical frequency, f o f 2. Measured data from September 2004 to August 2005 (a period of low solar activity) are analyzed based on the diurnal and seasonal variation and then compared with IRI-2007 model predictions. Our results show that, in general, the diurnal and seasonal variations of the N m F 2 predicted by the IRI (URSI and CCIR options) model show a feature generally similar to the observed N m F 2. Underestimation mostly occurs in all seasons except during the September equinox and the December solstice at Chumphon, and the September equinox and the March equinox at Chiang Mai, when they overestimate those measured. The best agreement between observation and prediction occurs during the pre-sunrise to post-sunrise hours. The best agreement of the %PD values of both the options occurs during the March equinox, while the agreement is the worst during the September equinox. The N m F 2 values predicted by the CCIR option show a smaller range of deviation than the N m F 2 values predicted by the URSI option. During post-sunset to morning hours (around 21:00-09:00 LT), the observed N m F 2 at both stations are almost identical for the periods of low solar activity. However, during daytime, the observed N m F 2 at Chumphon is lower than that at Chiang Mai. The difference between these two stations can be explained by the equatorial ionospheric anomaly (EIA). These results are important for future improvements of the IRI model for N m F 2 over Southeast Asia, especially for the areas covered by Chumphon and Chiang Mai stations.

  10. Projecting the impact of climate change on phenology of winter wheat in northern Lithuania

    NASA Astrophysics Data System (ADS)

    Juknys, Romualdas; Velička, Rimantas; Kanapickas, Arvydas; Kriaučiūnienė, Zita; Masilionytė, Laura; Vagusevičienė, Ilona; Pupalienė, Rita; Klepeckas, Martynas; Sujetovienė, Gintarė

    2017-10-01

    Climate warming and a shift in the timing of phenological phases, which lead to changes in the duration of the vegetation period may have an essential impact on the productivity of winter crops. The main purpose of this study is to examine climate change-related long-term (1961-2015) changes in the duration of both initial (pre-winter) and main (post-winter) winter wheat vegetation seasons and to present the projection of future phenological changes until the end of this century. Delay and shortening of pre-winter vegetation period, as well as the advancement and slight extension of the post-winter vegetation period, resulted in the reduction of whole winter wheat vegetation period by more than 1 week over the investigated 55 years. Projected changes in the timing of phenological phases which define limits of a main vegetation period differ essentially from the observed period. According to pessimistic (Representative Concentration Pathways 8.5) scenario, the advancement of winter wheat maturity phase by almost 30 days and the shortening of post-winter vegetation season by 15 days are foreseen for a far (2071-2100) projection. An increase in the available chilling amount is specific not only to the investigated historical period (1960-2015) but also to the projected period according to the climate change scenarios of climate warming for all three projection periods. Consequently, the projected climate warming does not pose a threat of plant vernalization shortage in the investigated geographical latitudes.

  11. 75 FR 21048 - Northern Lights Fund Trust, et al.; Notice of Application

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-22

    ... SECURITIES AND EXCHANGE COMMISSION [Investment Company Act Release No. 29208; 812-13651] Northern Lights Fund Trust, et al.; Notice of Application April 16, 2010. AGENCY: Securities and Exchange... shareholder approval and would grant relief from certain disclosure requirements. Applicants: Northern Lights...

  12. 76 FR 11773 - Environmental Management Site-Specific Advisory Board, Northern New Mexico

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-03

    ... DEPARTMENT OF ENERGY Environmental Management Site-Specific Advisory Board, Northern New Mexico... the Environmental Management Site-Specific Advisory Board (EM SSAB), Northern New Mexico. The Federal... Courtyard by Marriott, 3347 Cerrillos Road, Santa Fe, New Mexico 87507. FOR FURTHER INFORMATION CONTACT...

  13. A Deep Search for Biomarker Gases on Mars in 2009 - 2010: The Campaign and a Few Preliminary Results

    NASA Astrophysics Data System (ADS)

    Mumma, M. J.; Villanueva, G. L.; Novak, R.; Radeva, Y. L.; Kaufl, H.; Smette, A.; Hartogh, P.; Encrenaz, T.

    2010-12-01

    We searched for possible biomarker gases on Mars in the 2009-2010 observing season, emphasizing nine molecules (H2_O, CH_4_, C2_H_6_, C2_H_4_, CH3_OH, H_2_CO, H2_S, and N_2_O) of fundamental astrobiological importance along with HDO and CO2_. Our search utilized Earth’s most advanced ground-based infrared spectroscopic facilities in a campaign of several dozen observing runs spanning the period 19 August 2009 to 10 June 2010. Over this interval (L_s_ = 324 - 103 degrees), the season in Mars’ Northern hemisphere progressed from mid-winter, through vernal equinox and spring, and into early summer. We used long-slit high-resolution infrared spectrometers at the Keck and NASA-IRTF observatories in Hawaii, and the European Southern Observatory in Chile (VLT, Paranal). The spectral resolving powers ranged from ~ 35,000 (NIRSPEC/Keck and CSHELL/IRTF) to ~ 90,000 (CRIRES, VLT). At the sub-Earth point, the spatial resolution in non-AO mode ranged from ~600 km (FWHM) to ~ 400 km at Keck and IRTF. Using the adaptive optics (AO) mode at Keck and at VLT, we achieved an improved resolution of ~250 km (FWHM). We mapped the planet over the Earth-facing hemisphere by orienting the slit North-South in longitude and stepping it East-West across the planet, and we acquired deep searches over restricted longitude ranges by holding the slit fixed in position and taking sequential spectra as Mars rotated under it. Spectral lines of CO2_, H_2_O, HDO, and O2_ (a^1^Δg_) are obvious, even in the raw data. In the methane region near 3.3µm, removal of terrestrial and solar spectral lines revealed multiple lines of Mars H_2_O and CO2_, from which we extracted 2-D (lat-long) maps of Martian water vapor, atmospheric surface pressure and temperature. Subtraction of these features provided highly sensitive searches for trace gases. Preliminary results of searches for CH_4_, C2_H_4_, and C2_H_6_ will be presented in this paper. Radeva et al. (this meeting) will present preliminary results for

  14. 76 FR 23787 - Ashley Resource Advisory Committee

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-28

    ... Resource Advisory Committee AGENCY: Forest Service, USDA. ACTION: Notice of meeting. SUMMARY: The Ashley Resource Advisory Committee will meet in Vernal, Utah. The committee is meeting as authorized under the...

  15. 78 FR 66011 - Allergenic Products Advisory Committee; Notice of Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-04

    ... vernal, orchard, perennial rye, Timothy, and Kentucky bluegrass mixed pollens allergen extract tablet for... to discuss and make recommendations on the safety and efficacy of Grastek, a Timothy grass pollen...

  16. Strip clearcutting to regenerate northern hardwoods.

    Treesearch

    Frederick T. Metzger

    1980-01-01

    Describes results of strip clearcutting trials in mature northern hardwood and hemlock-hardwood stands in the Lake States. Two strip width and orientations were tested, with and without herbicide treatment of the advance regeneration. Establishment, growth, and species composition of the regeneration were assessed.

  17. An introduction to the biology of Northern krill (Meganyctiphanes norvegica Sars).

    PubMed

    Tarling, Geraint A; Ensor, Natalie S; Fregin, Torsten; Goodall-Copestake, William P; Fretwell, Peter

    2010-01-01

    This chapter provides a background to research on Northern krill biology, starting with a description of its morphology and identifying features, and the historical path to its eventual position as a single-species genus. There is a lack of any euphausiid fossil material, so phylogenetic analysis has relied on comparative morphology and ontogeny and, more recently, genetic methods. Although details differ, the consensus of these approaches is that Meganyctiphanes is most closely related to the genus Thysanoessa. The light organs (or photophores) are well developed in Northern krill and the control of luminescence in these organs is described. A consideration of the distribution of the species shows that it principally occupies shelf and slope waters of both the western and eastern coasts of the North Atlantic, with a southern limit at the boundary with sub-tropical waters (plus parts of the Mediterranean) and a northern limit at the boundary with Arctic water masses. Recent evidence of a northward expansion of these distributional limits is considered further. There have been a variety of techniques used to sample and survey Northern krill populations for a variety of purposes, which this chapter collates and assesses in terms of their effectiveness. Northern krill play an important ecological role, both as a contributor to the carbon pump through the transport of faecal material to the deeper layers, and as a key prey item for groundfish, squid, baleen whales, and seabirds. The commercial exploitation of Northern krill has been slow to emerge since its potential was considered by Mauchline [Mauchline, J (1980). The biology of mysids and euphausiids. Adv. Mar. Biol. 18, 1-681]. However, new uses for products derived from krill are currently being found, which may lead to a new wave of exploitation. Copyright © 2010 Elsevier Ltd. All rights reserved.

  18. Young Women's Positive and Negative Perceptions of Self in Northern Ireland

    ERIC Educational Resources Information Center

    McAlister, Siobhan; Neill, Gail

    2007-01-01

    This paper represents analysis of one aspect of a larger research project examining the everyday lives and experiences of young women in Northern Ireland. As an introductory exercise within focus groups, 48 young women considered and discussed the good and not so good things about being a young woman in Northern Ireland. Through these accounts…

  19. Human and biophysical factors influencing modern fire disturbance in northern Wisconsin

    Treesearch

    Brian R. Sturtevant; David T. Cleland

    2007-01-01

    Humans cause most wildfires in northern Wisconsin, but interactions between human and biophysical variables affecting fire starts and size are not well understood. We applied classification tree analyses to a 16-year fire database from northern Wisconsin to evaluate the relative importance of human v. biophysical variables affecting fire occurrence within (1) all cover...

  20. Is seedling grading beneficial to artificial regeneration of northern red oaks?

    Treesearch

    Paul P. Kormanik; Shi-Jean S. Sung; Stanley J. Zarnoch

    2005-01-01

    Effective and consistent success with artificial regeneration of northern red oak (Quercus rubra L.) has been achieved on many sites using 1-0 graded seedlings produced with the nursery protocol developed by the USDA Forest Service at the Institute of Tree Root Biology in cooperation with the Georgia Forestry Commission. Small northern red oak (NRO)...