3,388 research outputs found

    Brain Cholinesterase Depression and Mortality of Bobwhite Chicks Exposed to Granular Chlorpyrifos or Fonofos Applied to Peanut Vines

    Get PDF
    Granular-formulated insecticides are applied on over 60% of the peanut acreage in North Carolina, each year, to control southern com rootwonn. This application is applied as a 0.45m band overtop peanut vines between June and August. Lorsban® 15G (chlorpyrifos) and Dyfonate® 15G (fonofos) are used 90% of the time by peanut growers. Quail chicks foraging within or on the edge of peanut fields may consume granules as grit material as the insecticide granules are not soil-incorporated. Therefore. we examined the hazard posed by these insecticides to bobwhite chicks foraging in peanut fields. Two identical experiments were conducted in which 4, 15X!50m plots, were treated with Lorsban 15G or Dyfonate 15G and 2 plots were untreated. Human-imprinted bobwhite chicks (N = 7-9 chicks per plot) from two age groups, 4-7 or 11-12 days, were allowed to forage for one hour in treated and control plots. Brain cholinesterase (ChE) activity and ChE depression, relative to control ChE values, were determined for each chick. Differences in ChE activity between treatments were tested for using a two-way ANOVA with broods serving as the experimental unit. Relationships of age to ChE depression, within treatments, were analyzed separately using linear regression. Chicks foraging in peanut fields were observed ingesting granules directly and indirectly via granules adhered to arthropods. Chick brain ChE depression averaged 22% (SE = 3.6) and 8% (SE = 3.2) for chicks exposed to Dyfonate and Lorsban, respectively. Brain ChE was significantly lower than control values for chicks exposed to Dyfonate (P = 0.014 ). While ChE depression was not correlated to chick age (P \u3e 0.15), two 4-day-old quail chicks exposed to Dyfonate died and one 7-day-old chick was unable to walk. Chicks exposed to Dyfonate were lethargic and brooded whereas chicks exposed to Lorsban and control chicks showed no overt behavioral changes. Our results indicate that this application of Lorsban 15G presents a relatively low hazard to quail chicks foraging in recently treated peanut fields. In a follow-up experiment, chicks foraging in Dyfonate-treated peanut fields, I day post-application, exhibited less ChE depression (x = 12%, SD = 10.2) than chicks exposed immediately following the application, suggesting the hazard from Dyfonate may be temporary

    Exposure of Captive Bobwhites to an At-Planting Application of Terbufos (Counter 15G) to Corn

    Get PDF
    Terbufos is a highly toxic, organophosphate insecticide that is commonly applied to com fields during planting. Quail use crop field edges during April, when com is planted in North Carolina, and consequently may be exposed to at-planting insecticides. Therefore, we attempted to quantify the hazards to quail from an at-planting, banded application of Counter® 15G using penned northern bobwhite quail. Eight, 7.5 X 7.5m pens were placed in cornfields immediately after planting. Six field pens received Counter 15G at 22.7g per IOOm of cornrow. Pens were placed such that a 2.5 X 7.5m section was located in standing wheat. The remainder of each pen extended past the turnrows into a section of regular rows in each cornfield. Two quail of each sex were placed in each pen. Behavior of quail using cornfields was observed from blinds and categorized as feeding, loafing, dusting and other. Blood serum, for determining cholinesterase (ChE) activity, was collected from a sub-sample of quail (n = 3) from each pen prior to and at 1.5, 8.5 and 15.5 days following exposure. Change in (ChE) activity from pre-exposure levels was determined and averages for birds from each pen were compared between treatments using a one-way analysis of variance. In quail exposed to terbufos, serum ChE activity declined 21% relative to pre-exposure levels at 1.5 days (P = 0.04; df = 1,4), but not at later dates sampled (P \u3e 0.08). No mortality was observed. Observations of quail in pens revealed no unusual behaviors or changes in behavioral patterns over the course of the study. Our results suggest that Counter® 15G is unlikely to cause mortality or significant behavioral changes in wild quail inhabiting farms

    Relative amplitudes of P and S waves as a mantle reconnaissance tool

    Get PDF
    The unified magnitude, the ratio of the amiplitudes of S to P waves, and travel-time residuals were compiled from published data for the five Seismological Observatories, TFO, UBO, BMO, WMO and CBO. Using one of the stations as a reference, a relative measure of the above quantities was calculated for each of the other stations for each of a number of earthquakes. The stations in the Basin and Range Province are consistent with a markedly higher attentuation of P waves and a high attenuation of S relative to P when compared to the other stations. This latter observation indicates a high Poisson's ratio in the mantle under the Basin and Range. The delay times to these stations are also consistent with the high Poisson's ratio and with a low-velocity upper mantle. The ratio of the amplitudes of long-period S waves to short-period P waves varies by a factor of 4 among these stations. BMO, in eastern Oregon, has a high S/P amplitude ratio compared to other stations and a travel-time residual that is comparable to the observatories in the mid-continent. This may be another example of a seismic “window” into the upper mantle that is generated by underthrusting of the oceanic lithosphere

    Indication, from Pioneer 10/11, Galileo, and Ulysses Data, of an Apparent Anomalous, Weak, Long-Range Acceleration

    Get PDF
    Radio metric data from the Pioneer 10/11, Galileo, and Ulysses spacecraft indicate an apparent anomalous, constant, acceleration acting on the spacecraft with a magnitude 8.5×108\sim 8.5\times 10^{-8} cm/s2^2, directed towards the Sun. Two independent codes and physical strategies have been used to analyze the data. A number of potential causes have been ruled out. We discuss future kinematic tests and possible origins of the signal.Comment: Revtex, 4 pages and 1 figure. Minor changes for publicatio

    Effects of Filter Strips on Habitat Use and Home Range of Northern Bobwhites on Alligator River National Wildlife Refuge

    Get PDF
    Lack of breeding habitat for northern bobwhites (Colinus virginianus) on agricultural landscapes is a factor that limits populations. Therefore, we examined how the addition of filter strips around crop fields and along crop field drainage ditches impacted northern bobwhites. Our study focused on habitat use, home range and brood-rearing range of bobwhites, from April through September I 993-94. Two farms on Alligator River National Wildlife Refuge were sub-divided into filter strip (FS) and non-filter strip (NFS) sections. More bobwhites were found on FS sections than on NFS sections based on flush counts (4.3x more on FS areas: P = 0.02). We used log-linear analysis to examine the distribution of telemetry locations (n = 1796) of radio-marked bobwhites (n = 218) across 5, 4.6m bands parallel to drainage ditches. Bobwhite locations were skewed towards ditches, particularly on FS sections before soybeans matured to a size that was sufficient to provide canopy cover for bobwhites. Bobwhites captured on FS sections had significantly smaller breeding season ranges than those captured on NFS sections (P = 0.001). Adult and sub-adult breeding season (May-Aug) ranges (n = 23) averaged 32 ha (SE = 26) and 182 ha (SE = 41) on FS and NFS sections, respectively. Brood ranges to 14 days (n = 9) ranged from 0.8 ha to 2.2 ha depending on habitat and calculation method. Presence of filter strips shifted habitat use patterns, especially during spring and early summer, and improved crop fields as habitat for breeding bobwhites

    Correspondence to Elizabeth ( Bessie ) McCaw Boggs Taylor, August 31, 1888 - December 10, 1901

    Get PDF
    Correspondence to Elizabeth ( Bessie ) McCaw Boggs Taylor, August 31, 1888 - December 10, 1901. Box 2, folder 5.https://digitalcommons.wofford.edu/littlejohnboggs/1015/thumbnail.jp

    The Effect of 17-4 PH Stainless Steel on the Lifetime of a Pennzane(Trademark) Lubricated Microwave Limb Sounder Antenna Actuator Assembly Ball Screw for the AURA Spacecraft

    Get PDF
    During ground based life testing of a Microwave Limb Sounder (MLS) Antenna Actuator Assembly (AAA) ball-screw assembly, lubricant darkening and loss were noted when approximately 10 percent of required lifetime was completed. The MLS-AAA ball screw and nut are made from 17-4 PH steel, the nut has 440C stainless steel balls, and the assembly is lubricated with a Pennzane formulation containing a three weight percent lead naphthenate additive. Life tests were done in dry nitrogen at 50 C. To investigate the MLS-AAA life test anomaly, Spiral Orbit Tribometer (SOT) accelerated tests were performed. SOT results indicated greatly reduced relative lifetimes of Pennzane formulations in contact with 17-4 PH steel compared to 440C stainless steel. Also, dry nitrogen tests yielded longer relative lifetimes than comparable ultrahigh vacuum tests. Generally, oxidized Pennzane formulations yielded shorter lifetimes than non-oxidized lubricant. This study emphasizes surface chemistry effects on the lubricated lifetime of moving mechanical assemblies

    Five High-Redshift Quasars Discovered in Commissioning Imaging Data of the Sloan Digital Sky Survey

    Get PDF
    We report the discovery of five quasars with redshifts of 4.67 - 5.27 and z'-band magnitudes of 19.5-20.7 M_B ~ -27. All were originally selected as distant quasar candidates in optical/near-infrared photometry from the Sloan Digital Sky Survey (SDSS), and most were confirmed as probable high-redshift quasars by supplementing the SDSS data with J and K measurements. The quasars possess strong, broad Lyman-alpha emission lines, with the characteristic sharp cutoff on the blue side produced by Lyman-alpha forest absorption. Three quasars contain strong, broad absorption features, and one of them exhibits very strong N V emission. The amount of absorption produced by the Lyman-alpha forest increases toward higher redshift, and that in the z=5.27 object (D_A ~ 0.7) is consistent with a smooth extrapolation of the absorption seen in lower redshift quasars. The high luminosity of these objects relative to most other known objects at z >~ 5 makes them potentially valuable as probes of early quasar properties and of the intervening intergalactic medium.Comment: 13 pages in LaTex format, two postscirpt figures. Submitted to the Astronomical Journa

    The pre-vaccination regional epidemiological landscape of measles in Italy: contact patterns, effort needed for eradication, and comparison with other regions of Europe

    Get PDF
    BACKGROUND: Strong regional heterogeneity and generally sub-optimal rates of measles vaccination in Italy have, to date, hampered attainment of WHO targets for measles elimination, and have generated the need for the new Italian National Measles Elimination Plan. Crucial to success of the plan is the identification of intervention priorities based upon a clear picture of the regional epidemiology of measles derived from the use of data to estimate basic parameters. Previous estimates of measles force of infection for Italy have appeared anomalously low. It has been argued elsewhere that this results from Italian selective under-reporting by age of cases and that the true measles force of infection in Italy is probably similar to that of other European countries. A deeper examination of the evidence for this conjecture is undertaken in the present paper. METHODS: Using monthly regional case notifications data from 1949 to the start of vaccination in 1976 and notifications by age from 1971–76, summary equilibrium parameters (force of infection (FOI), basic reproductive ratio (R(0)) and critical vaccination coverage (p(c))) are calculated for each region and for each of 5 plausible contact patterns. An analysis of the spectra of incidence profiles is also carried out. Finally a transmission dynamics model is employed to explore the correspondence between projections using different estimates of force of infection and data on seroprevalence in Italy. RESULTS: FOI estimates are lower than comparable European FOIs and there is substantial regional heterogeneity in basic reproductive ratios; certain patterns of contact matrices are demonstrated to be unfeasible. Most regions show evidence of 3-year epidemic cycles or longer, and compared with England & Wales there appears to be little synchronisation between regions. Modelling results suggest that the lower FOI estimated from corrected aggregate national data matches serological data more closely than that estimated from typical European data. CONCLUSION: Results suggest forces of infection in Italy, though everywhere remaining below the typical European level, are historically higher in the South where currently vaccination coverage is lowest. There appears to be little evidence to support the suggestion that a higher true force of infection is masked by age bias in reporting

    The Sub-axial Cervical Spine Injury Classification System (SLIC): A Novel Approach to Recognize The Importance of Morphology, Neurology and Integrity of the Disco-ligamentous complex

    Get PDF
    Abstract Background Context Despite technological advances in spine surgery, classification of sub-axial cervical spine injuries remains largely descriptive, lacking standardization and any relationship to prognosis or clinical decision making. Purpose The primary purpose of this paper is to define a classification system for sub-axial cervical spine trauma that conveys information about injury pattern and severity as well as treatment considerations and prognosis. The proposed system is designed to be both comprehensive and easy to use. The secondary objective is to evaluate the classification system in the basic principles of classification construction, namely reliability and validity. Study Design/Setting Derivation of the classification was from a synthesis of the best cervical classification parameters gleaned from an exhaustive literature review and expert opinion of experienced spine surgeons. Multi-center reliability and validity study of a cervical classification system using previously collected CT, MRI, and plain film x-ray images of sub-axial cervical trauma. Methods Important clinical and radiographic variables encountered in sub-axial cervical trauma were identified by a working section of the Spine Trauma Study Group (STSG). Significant limitations of existing injury classification systems were defined and addressed within the new system. It was then introduced to the STSG and applied to 11 cervical trauma cases selected to represent a spectrum of subaxial injury. Six weeks later, the cases were randomly re-ordered and again scored using the novel classification system. Twenty surgeons completed both intervals. Inter-rater and intra-rater reliability and several forms of validity were assessed. For comparison, the reliability of both the Harris and the Ferguson & Allen systems were also evaluated. Results Each of three main categories (injury morphology; disco-ligamentous complex integrity; and neurological status) identified as integrally important to injury description, treatment, and prognosis was assigned an ordinal score range, weighted according to its perceived contribution to overall injury severity. A composite injury severity score was modeled by summing the scores from all three categories. Treatment options were assigned based upon threshold values of the severity score. Inter-rater agreement as assessed by ICC of the DLC, Morphology, and Neurological Status scores was 0.49, 0.57, and 0.87, respectively. Intra-rater agreement as assessed by ICC of the DLC, Morphology, and Neurological Status scores was 0.66, 0.75, and 0.90, respectively. Raters agreed with treatment recommendations of the algorithm in 93.3 % of cases, suggesting high construct validity. The reliability if the SLIC treatment algorithm compared favorably to the earlier classification systems of Harris and Ferguson & Allen. Conclusions The Sub-axial Injury Classification (SLIC) and Severity Scale provides a comprehensive classification system for sub-axial cervical trauma, incorporating pertinent characteristics for generating prognoses and courses of management. Early data on validity and reliability are encouraging. Further testing is necessary before introducing the SLIC score into clinical practice
    corecore