Showing papers in "Virginia journal of science in 2010"

Foundational Checklist of the Amphibians of Wise County, Virginia

Abstract: The objective of this study was to assess the feasibility of identiying minerals on Mars using remotely sensed data. In the process we also investigated the effect of noise of aerosol and dust particles on the spectra of Mars minerals. The remotely sensed data was obtained through modeling and simulation and compared to the lab spectroscopy of the specific minerals in order to make an accurate identification. A linear model was developed using MATLAB Random Number Generator to obtain a simulated image. Part of the information we needed for the linear model was pure pixel information of Mars which was obtained from Mars Spirit images. Random noise was added to the image in order to simulate a real world image. In addition to the random noise, a mathematical model was developed to represent the noise caused by aerosols and dust particles in Mars’s atmosphere. The simulation was tested to ensure that it satisfied the appropriate model testing. Our results showed that our linear model was appropriate, and was accepted at a confidence interval of about 95%. The simulated image was then corrected from noise through iterations. The overall accuracy of the corrected image showed an improvement in classification by 25%. The signatures of the spectra of the two images were obtained and compared to the lab spectroscopy of specific minerals. The degradation of noise showed improvement in the spectral analysis of Mars data. The spectral analysis showed the presence of iron oxide, calcium oxide and magnesium oxide leading to the conclusion that the image simulation is reliable in mineral spectral identification.

Garlic as an Alternative Anthelmintic in Sheep

Abstract: An increase in the anthelmintic resistance of parasites in small ruminants and a push towards non-chemical farming has lead researchers to search for alternative forms of anthelmintics. The efficacy of treating sheep by using natural garlic extract with respect to changes in weight, fecal egg counts (FEC), and packed cell volume (PCV) was investigated. Sheep were treated every 4 weeks for 8 weeks with saline (control), Ivermectin, or natural garlic extract and samples were collected weekly to determine FEC and PCV. Sheep were weighed at the time of sample collection to determine weight change. There were no significant differences between the Ivermectin and natural garlic extract treated sheep with respect to weight changes, FEC or PCV. The Ivermectin and natural garlic extract treated sheep had significantly greater (P < 0.05) weight changes and PCV compared to the control. The control sheep had a significantly higher (P < 0.05) FEC compared to the Ivermectin and natural garlic extract treated sheep. Administering natural garlic extract as anthelmintic is a variable alternative to Ivermectin. INTRODUCTION Small ruminant gastrointestinal nematodes potentially reduce production and cause profit loss throughout the sheep industry (Perry and Randolph, 1999). Traditionally, producers have used commercially available anthelmintics (benzimidazoles, imidazothiazoles-tetrahydropyrimidines, and avermectins-milbemycins) to control parasites. However, an increase in the anthelmintic resistance of parasites is currently a serious threat and research is being done to find alternative forms of anthelmintics (Larson, 2006). The societal push towards non-chemical (eco-friendly, green, organic) farming has also hastened the search for viable alternatives to chemical anthelmintics (Waller and Thamsborg, 2004). Haemonchus Contortus, often referred to as the "barber pole" worm, punctures the lining of the abomasum, causing blood plasma and protein loss in sheep. Since it is usually the most prevalent nematode parasite in sheep and causes the most destruction, a majority of the research in alternative forms of anthelmintics has been targeting H. Contortus. Copper oxide wire particles administered to sheep have been shown to reduce the number of H. Contortus strongyle eggs shed in lambs (Burke et al., 2004) as well as pregnant ewes (Burke et al., 2005). Developing vaccinations against parasites is becoming a reality with the use of recombinant protein-based vaccines (Knox, 2000), however the economical availability of such vaccines to producers is Corresponding Author: B. D. Whitaker, University of Findlay, 1000 1 North Main Street, Findlay OH, 45840, USA. E-mail: whitaker@findlay.edu Virginia Journal of Science, Vol. 61, No. 1, 2010 http://digitalcommons.odu.edu/vjs/vol61/iss1 4 VIRGINIA JOURNAL OF SCIENCE currently not a possibility. Additional research has shown that feeding forages high in tannin content reduces the fecal egg counts (FEC) and number of worms in goats (Shaik et al., 2006). Strong evidence suggests that using chlamydospores (nematode ingesting fungi) as an anthelmintic in sheep is very successful (Fontenot et al., 2004) however it has not been shown to target H. Contortus. Although not an alternative treatment, research indicates that breeding and selecting for ewes with higher genetic merit for growth as lambs, and lambs with higher genetic merit for body weight, were all more resistant to infection as adults (Vanimisetti et al., 2004). Any novel treatment needs to easily be incorporated into a producers flock management and be economically feasible (van Wyk et al., 2006). The current techniques available to test the efficacy of any treatment are serology testing, the FAMACHA chart based on the color of the eye membrane mucosa (measures relative levels of anemia) (van Wyk and Bath, 2002), and FEC (Cringoli et al., 2004). Novel treatments and management systems should be able to be evaluated using the above techniques. Therefore, the objectives of this study were to compare the use of natural garlic extract to Ivermectin as an anthelmintic for sheep with respect to, 1) change in body weight (BW), 2) FEC, and 3) packed cell volume (PCV) based on serology analysis. MATERIALS AND METHODS Experimental Site and Treatment Groups This study was carried out at the Ferrum College Agriculture Center in Ferrum, Virginia (36o92'N), between May and September 2009. The experimental site was at an altitude of 430 m and consisted of a 0.5 ha plot containing a clean fescue and orchard grass mix. Free access to unlimited water was available throughout the study. A total of 14, 90-d sheep (American black-faced) ranging from 18 to 32 kg (average = 26 kg) were randomly assigned to receive orally either saline (control), natural garlic extract (Garlic Barrier, Glendale CA, 1 teaspoon/head), or Ivermectin (Merial Ivomec, Atlanta GA, 42 mg/kg bodyweight). All sheep were treated on week 0 and week 4 of the 9 week study. Samples were collected each week for analysis. Body Weight Measurements Sheep were weighed weekly using an electronic scale (A and A Scales LLC, Prospect Park, NJ, USA) to monitor changes in BW. Fecal Egg Counts Feces were taken rectally using the gloved hand method and stored at 4< C until analysis. All FEC were performed using the McMaster method (Cringoli et al., 2004). Briefly, approximately 4.0 g fecal material was placed in a 50 mL graduated cylinder and Sodium Nitrate (1.2 – 1.25 specific gravity) was added to bring to final volume to 26 mL. The solution was homogenized, filtered through 2 layers of cheesecloth, and immediately 1.0 mL of resulting solution was placed on a McMaster slide. The slide was incubated at room temperature for 5 min to allow the eggs to float to the top of the solution and strongyle eggs were counted at 100X using a compound light microscope. Virginia Journal of Science, Vol. 61, No. 1, 2010 http://digitalcommons.odu.edu/vjs/vol61/iss1 GARLIC ANTHELMINTIC FOR SHEEP 5 Immune Response Whole blood was obtained via jugular venipuncture (BD Vacutainer, 12 mg EDTA, Franklin Lakes, NJ) at stored at 4

Functional Feeding Groups, Species Richness, and Spatial Distributions of Fishes in Rocky and Sandy Beach Habitats of St. John, U.S. Virgin Islands

Abstract: Objectives were to identify and compare fish species richness, functional feeding group richness and diversity, and delineate distributions of fishes at rocky and sandy beach habitats at St. John, U.S. Virgin Islands. Visual observations using snorkel and mask were made at 3-m intervals seaward from shore during daylight hours. A total of 69 taxa (67 species) representing 33 families of fishes were observed. Total (53) and average fish species richness (32.7) at rocky beach habitats were greater than those (total=43; average=24.3) at sandy beach habitats. Twelve functional feeding groups were identified (diurnal planktivores, excavators/eroders, macroalgae browsers, macrocarnivores, mobile benthic invertivores, general omnivores, strict piscivores, sand invertivores, scrapers, coral/colonial sessile insectivores, territorial algae/detritus, and turf grazers). Total numbers of functional feeding groups (range=10-12) and species (range=29-46) per functional feeding groups at distances greater than 1 m from shore at rocky beach habitats were consistently higher than those (functional feeding group range=8-10; species per functional feeding group=19-30) at sandy beach habitats. Information on the number and composition of functional feeding groups in rocky and sandy beach habitats from this study can serve as a baseline for future investigations as changes in Caribbean habitats continue to occur.

A Habitat Model for the Detection of Two-lined Salamanders at C. F. Phelps Wildlife Management Area, Fauquier and Culpeper Counties, Virginia

Abstract: Aquatic salamanders represent an important component of Virginia river watersheds, but despite potential declines, few specifics are known about their habitat preferences. We surveyed the habitats of the northern two-lined salamander and collected data on an array of habitat variables associated with the species. We used a logistic regression analysis to develop a model predicting its presence or absence for a given 50m-transect. Our final model incorporated the variation in stream depth and direction of stream flow and accounted for 25% of the variation in our data. We conclude that stream depth variation is an important feature of salamander habitat ecology, and surmise that direction of flow is of site-specific importance possibly related to stream order. Both features may be behavioral adaptations to avoid fish predation. INTRODUCTION Stream-dwelling salamanders are an important component of aquatic ecosystems. They account for a significant proportion of the biomass of a stream ecosystem, and act as a key trophic link, important as both predators and prey (Spight 1967, Burton and Likens 1975, Rocco and Brooks 2000). Consequently, these salamanders have potential to act as an indicator of stream health (Rocco and Brooks 2000, Barr and Babbitt 2002). This is particularly true for headwater streams were salamanders may act as the dominant vertebrate predator (Davic and Welsh 2004). Accordingly, it would be beneficial to better understand how these species make use of their available habitat. This is especially important in the face of on-going amphibian declines (Alford and Richards 1999). Knowledge of this type may provide better insights into the conservation of these species and their associated ecosystems (Cushman 2005). Previous surveys of stream and terrestrial amphibian diversity have been carried out in the Rappahannock River watershed of northern Virginia; however, more needs to be done to quantify the habitat preferences of important stream species (Mitchell 1998, McGhee and Killian 2010). To begin addressing this need, we conducted a preliminary study of salamander habitat at C.F. Phelps Wildlife Management Area (WMA) located in the Rappahannock River watershed and developed a simple habitat model for the Virginia Journal of Science Volume 61 Number 4 Winter 2010 1 Corresponding author. E-mail: jaymcghee@rmc.edu Virginia Journal of Science, Vol. 61, No. 4, 2010 http://digitalcommons.odu.edu/vjs/vol61/iss4 152 VIRGINIA JOURNAL OF SCIENCE northern two-lined salamander (Eurycea bislineata), a common stream species for the area (McGhee and Killian 2010). Northern two-lined salamanders are common to northern Virginia forest streams within the Rappahannock River watershed (Mitchell and Reay 1999). While they are considered potentially important components of the local ecosystems in which they occur, few studies have developed predictive models of habitat use (Davic and Welsh 2004). They occupy stream margins and seeps, using submerged rocks and woody debris for cover; but may periodically be found in upland terrestrial sites (Petranka 1998). Females attach eggs beneath submerged rocks of varying surface area in headwater streams (Jakubanis et al. 2008). Larvae of this species are benthic predators associated with stream pools with low silt (Smith and Grossman 2003, Petranka 1998). Two-lined salamanders are able to access low-order streams typically inaccessible to predatory fishes, and have become adapted to these headwater stream environments (Vannote et al. 1980, Davic and Welsh 2004). We hypothesized that two-lined salamanders would be detected in or near cool narrow, shallow streams. From this hypothesis, we predicted that important habitat variables in a logistic regression model would be stream temperature, stream depth, and stream width. METHODS We chose sampling sites by randomly selecting a GPS starting location constrained to occur within C. F. Phelps WMA, and moving from that point to the nearest stream. We then moved upstream or downstream a randomly selected distance of up to 50m, and laid a 50m transect running downstream. We sampled stream transects by searching five 1-m quadrats placed within each of the five 10-m sections of the 2 transect. The particular location of the quadrat within these 10-m sections was randomly selected (Jaeger 1994, Jaeger and Inger 1994). We searched quadrats by looking under larger cover objects such as rocks or decaying logs, leaf pack, leaf litter, and using a standard-mesh aquarium dip net (1/16 inch mesh size) to sample stream bottoms (Mitchell 2000). We identified captured salamanders to species (Petranka 1998). Data were collected at both transect and quadrat levels (Table 1). We used logistic regression to select models with those predictive variables most associated with salamander captures at the transect level. Variables measured at the quadrat level were averaged and averages and standard deviations were used as separate predictor variables. As synergistic effects may occur between the variables we measured, we created a priori multiplicative variables for testing as well (Table 1). We used forward stepwise selection (P = 0.05 to enter and 0.10 to remove) in SPSS (SPSS Inc., Chicago IL). We assessed variable coefficients using the change in -2 loglikelihood and evaluated the explanatory value of models using Nagelkerke’s r (Ryan 1997, Hosmer and Lemeshow 1989, Nagelkerke 1991). For all statistical

Modeling and Simulation on Signatures of Mars Minerals

Abstract: The objective of this study was to assess the feasibility of identiying minerals on Mars using remotely sensed data. In the process we also investigated the effect of noise of aerosol and dust particles on the spectra of Mars minerals. The remotely sensed data was obtained through modeling and simulation and compared to the lab spectroscopy of the specific minerals in order to make an accurate identification. A linear model was developed using MATLAB Random Number Generator to obtain a simulated image. Part of the information we needed for the linear model was pure pixel information of Mars which was obtained from Mars Spirit images. Random noise was added to the image in order to simulate a real world image. In addition to the random noise, a mathematical model was developed to represent the noise caused by aerosols and dust particles in Mars’s atmosphere. The simulation was tested to ensure that it satisfied the appropriate model testing. Our results showed that our linear model was appropriate, and was accepted at a confidence interval of about 95%. The simulated image was then corrected from noise through iterations. The overall accuracy of the corrected image showed an improvement in classification by 25%. The signatures of the spectra of the two images were obtained and compared to the lab spectroscopy of specific minerals. The degradation of noise showed improvement in the spectral analysis of Mars data. The spectral analysis showed the presence of iron oxide, calcium oxide and magnesium oxide leading to the conclusion that the image simulation is reliable in mineral spectral identification.