Ease Of Observation Research Articles

Using Social Media to Measure the Contribution of Red List Species to the Nature-Based Tourism Potential of African Protected Areas.

Cultural ecosystem services are defined by people’s perception of the environment, which make them hard to quantify systematically. Methods to describe cultural benefits from ecosystems typically include resource-demanding survey techniques, which are not suitable to assess cultural ecosystem services for large areas. In this paper we explore a method to quantify cultural benefits through the enjoyment of natured-based tourism, by assessing the potential tourism attractiveness of species for each protected area in Africa using the IUCN’s Red List of Threatened Species. We use the number of pictures of wildlife posted on a photo sharing website as a proxy for charisma, popularity, and ease of observation, as these factors combined are assumed to determine how attractive species are for the global wildlife tourist. Based on photo counts of 2473 African animals and plants, species that seem most attractive to nature-based tourism are the Lion, African Elephant and Leopard. Combining the photo counts with species range data, African protected areas with the highest potential to attract wildlife tourists based on attractive species occurrence were Samburu National Reserve in Kenya, Mukogodo Forest Reserve located just north of Mount Kenya, and Addo Elephant National Park in South-Africa. The proposed method requires only three data sources which are freely accessible and available online, which could make the proposed index tractable for large scale quantitative ecosystem service assessments. The index directly links species presence to the tourism potential of protected areas, making the connection between nature and human benefits explicit, but excludes other important contributing factors for tourism, such as accessibility and safety. This social media based index provides a broad understanding of those species that are popular globally; in many cases these are not the species of highest conservation concern.

Ultrasonographic measurement of fetal growth parameters over three successive pregnancies in a captive Malayan tapir (Tapirus indicus).

This study was conducted to establish representative curves that allow evaluation of fetal growth and estimation of gestational age from measurement of fetal structures by ultrasound in Malayan tapirs (Tapirus indicus). Three pregnancies (i.e. 3 fetuses) were examined in one female Malayan tapir. Transabdominal ultrasonographic examination was performed without anesthesia from 79 ± 8 days to 281 ± 48 days (mean ± S.D.) post mating. To assess fetal growth attempts were made to measure biparietal diameter (BPD), head length (HL), thorax diameter A (TDA), thorax height A (THA), thorax diameter B (TDB), thorax height B (THB), abdomen diameter (AD), abdomen height (AH), humerus length (HUL) and Crown rump length (CRL). The value of each parameter as an estimator of gestational age was assessed by ease of observation and the length of time the parameter was measurable throughout gestation. The most precise predictors for gestational age in this study were BPD and CRL (weeks 10-20 of gestation), as well as AD and AH (weeks 14-43 of gestation). The parameters TDB, THB and HUL (weeks 15-41 of gestation) gave almost as good predictions. Fetal viability was assessed by identifying a fetal heartbeat and movement. All pregnancies resulted in normal deliveries and healthy offspring. The ultrasound examination was well tolerated by the female. The gestation lengths (399 ± 3 days) were within reported ranges. The serial transabdominal ultrasound, without the need for anesthesia, was an effective method to evaluate fetal growth, development and well being in a Malayan tapir.

Behavior of Proteolipid GUVs formed in Macrovipera Lebetina Obtusa Venom Solution

Introduction: Macrovipera lebetina obtusa belongs to sister clade of the Middle East complex within the monophyletic Eurasian Vipera genus. This snake is responsible for a number of bites in western Asia every year, and should be considered as dangerous. Proteolipids are a type of lipoproteins in which lipid material forms more than half of the molecule solubilized in organic solvents (chloroform/methanol/water mixtures) and have the solubility characteristics of lipids. GUVs are ideal for studying protein/lipid and lipid/lipid interactions due to their size (similar to that of cells) and to their ease of observation by optical microscopy.Method: Proteolipid fraction was separated from the bovine brain by the Folch method. Proteolipid GUVs (mean diameter 30 μm) are formed with the electroformation method as developed by Angelova and Dimitrov. GUVs have a minimum curvature and mimic cell membranes in this respect. We formed proteolipid GUVs in the solution of Macrovipera lebetina obtusa (MLO) venom (final concentration 3∗10−5M). Images were collected on an epi-fluorescent microscope FM320-5M (AmScope, USA). The GUVs were visualized with ANS fluorescent probe.Results: While GUVs filled with proteins are more stable and there are little increases in size, the GUVs filled with fewer proteins are deformed, not stable. They diminish during 25 seconds, and eventually pull in and dissolve (instead of the usual vesicles formed from phospholipids). The same effect is seen, when MLO was added after GUVs formation.

Axisymmetric Drainage in Hydrophobic Porous Media Micromodels

We present studies of axisymmetric drainage in two-dimensional micromodels of porous media using up to date microfabrication and image analysis methods. Drainage of model oil by aqueous solutions is studied at low capillary numbers (Ca) typically encountered during oil recovery operations. We use two types of oil-wet micromodels: one is based on a deposition method for creating a random monolayer of micronic glass beads, while the other is made using computer generated random networks etched in glass using wet-lithography. Both models have a central injection scheme and a radial geometry, resulting in a continuous variation of the capillary number during the course of drainage. We first carry out an analysis of experiments at global micromodel scale using computer based image analysis coupled with flow rates and pressure drop measurements. Basic relevant parameters such as permeability, porosity of the micromodel and residual oil in place after waterflooding are extracted. We then take advantage of the ease of observation in transparent micromodels to investigate the drainage phenomenon at local scale. Local saturation and front width are measured as a function of the local capillary number. Interestingly, because of the radial flow geometry, our experiments allow a continuous plotting of the micromodels capillary desaturation curve on several decades. As expected but never precisely observed, all points of various experiments collapse on a single capillary desaturation curve for a given micromodel. However, we observe dissimilar behaviors between the two types of micromodels. We discuss this phenomenon in light of the pore scale geometrical differences between the two models.

A Humanized Stromal Bed Is Required for Engraftment of Isolated Human Primary Squamous Cell Carcinoma Cells in Immunocompromised Mice

Epithelial cancers are the most common malignancies and the greatest cause of cancer mortality worldwide. The incidence of keratinocyte-derived (non-melanoma) skin cancers (NMSCa) is increasing rapidly. Despite access to abundant tumor tissue and ease of observation, acceptance of NMSCa as model carcinomas has been hindered by the lack of a reliable xenograft model. Herein we describe conditions that allow routine xenoengraftment of primary human squamous cell carcinoma (SCCa) cells. Tumor development required creation of an appropriate stromal bed prior to xenografting tumor tissue onto the backs of athymic nude mice. We also demonstrate that the stromal bed must be “humanized” if primary human SCCa is to be propagated from cell suspensions. SCCa xenografts recapitulated the histological grade and phenotype of the original tumors with considerable fidelity, even after serial passage, irrespective of the histological grade of the primary human SCCa. To our knowledge this previously unreported model can be used for drug testing, as well as for studies that are relevant to the biology of primary human SCCa and other epithelial cancers.

Transparent Film Dressing vs Pressure Dressing After Percutaneous Transluminal Coronary Angiography

Pressure dressings have been used as the standard following sheath removal after percutaneous transluminal angioplasty in many institutions. Patients complain about discomfort while the dressing is in place, pain when the dressing is removed after discharge, and skin complications afterward. Many patients have experienced skin irritation where tape has been applied. Nurses have also described difficulty assessing the sheath insertion site in the groin when a pressure dressing is in place. To compare 3 different dressings with respect to effect on bleeding, discomfort voiced by patients, and ease of groin assessment in patients after percutaneous transluminal coronary angiography. A total of 100 patients were randomly assigned to 1 of 3 groups: pressure dressing, transparent film dressing, or adhesive bandage. Outcome variables were bleeding, patient discomfort, and nurse-reported ease of observation of the groin site. No bleeding occurred in patients with transparent film dressings or adhesive bandages. Patients rated these dressings significantly higher than they rated the pressure dressing. Because two-thirds of the sample had previously undergone percutaneous transluminal coronary angiography, they could compare their experience with the new dressing with previous experiences with pressure dressings. Nurses rated the ease of assessing the groin significantly higher for the transparent film and adhesive bandage dressings than for pressure dressings. As a result of this study, a practice change was made hospital-wide: rather than a standard opaque pressure dressing, a transparent film dressing is used for all patients after removal of a femoral sheath.

Solvent signal as an NMR concentration reference.

We propose that the NMR solvent signal be utilized as a universal concentration reference because most solvents can be observed by NMR and solvent concentrations can be readily calculated or determined independently. In particular, a highly protonated solvent such as water can serve as a primary concentration standard for its stability, availability, and ease of observation. The potential problems of radiation damping associated with a strong NMR signal can be alleviated by small pulse angle excitation. The solvent signal then can be detected by the NMR receiver with the same efficiency as a dilute analyte. We demonstrated that the analyte's proton concentration can be accurately determined from 4 microM to more than 100 M, referenced by solvent (water) protons of concentrations more than 10 M. The proposed method is robust and indifferent to probe tuning and does not require any additional concentration standard.

Giant Unilamellar Vesicles Containing Phosphatidylinositol(4,5)bisphosphate: Characterization and Functionality

Biomimetic systems such as giant unilamellar vesicles (GUVs) are increasingly used for studying protein/lipid interactions due to their size (similar to that of cells) and to their ease of observation by light microscopy techniques. Biophysicists have begun to complexify GUVs to investigate lipid/protein interactions. In particular, composite GUVs have been designed that incorporate lipids that play important physiological roles in cellulo, such as phosphoinositides and among those the most abundant one, phosphatidylinositol(4,5)bisphosphate (PIP 2). Fluorescent lipids are often used as tracers to observe GUV membranes by microscopy but they can not bring quantitative information about the insertion of unlabeled lipids. In this study, we carried out ζ-potential measurements to prove the effective incorporation of PIP 2 as well as that of phosphatidylserine in the membrane of GUVs prepared by electroformation and to follow the stability of PIP 2-containing GUVs. Using confocal microscopy, we found that long-chain (C16) fluorescent PIP 2 analogs used as tracers (0.1% of total lipids) show a uniform distribution in the membrane whereas PIP 2 antibodies show PIP 2 clustering. However, the clustering effect, which is emphasized when tertiary antibodies are used in addition to secondary ones to enhance the size of the detection complex, is artifactual. We showed that divalent ions (Ca 2+ and Mg 2+) can induce aggregation of PIP 2 in the membrane depending on their concentration. Finally, the interaction of ezrin with PIP 2-containing GUVs was investigated. Using either labeled ezrin and unlabeled GUVs or both labeled ezrin and GUVs, we showed that clusters of PIP 2 and proteins are formed.

Density and Excess Molar Volume of Binary Mixtures of p-Xylene+Acetic Acid and o-Xylene+Acetic Acid at Different Temperatures and Pressures

A new apparatus was designed with a thick-walled glass capillary, electric heater tube with red copper and heat preservation. The thick-walled glass capillary was used for its advantages of resistance to acid corrosion and pressure, and ease of observation. The experimental densities over the entire range of mole fraction for the binary mixture of p-xylene+acetic acid and o-xylene+acetic acid were measured using the new apparatus at temperatures ranging from 313.15K to 473.15K and pressure ranging from 0.20 to 2.0 MPa. The density values were used in the determination of excess molar volumes, V E. The Redlich-Kister equation was used to fit the excess molar volume values, and the coefficients and estimate of the standard error values were presented. The experimental results prove that the density measurement apparatus is successful.

DEVELOPMENT OF A CATALYTIC HYDROGEN MICRO-PROPULSION SYSTEM

In the present study, the feasibility of a catalytic hydrogen micro-propulsion system suitable for providing thrust for micro-satellite attitude control and orbit transfer is demonstrated and examined experimentally and numerically. The effects of major design and operational parameters of fuel/air flow rate, equivalence ratio and nozzle contraction ratio on the thruster performance are investigated. For ease of observation and numerical comparison, a platinum catalytic tube with an inner diameter of 500 µm and length 1 cm is used as the reactor and is tightly inserted into a quartz tube with a convergent nozzle made of quartz of different contraction ratios. For most of the cases tested in experiments, catalytic surface reaction occurs near entrance of the platinum tube due to the high diffusivity and high surface reaction rate of hydrogen. With increasing fuel concentration, the transition point from kinetic-controlled reaction to diffusion-controlled reaction moves further downstream. When the fuel velocity is increased, the hydrogen may not be consumed completely because of insufficient residence time. However, the unburned hydrogen has been heated, by upstream surface reactions, such that gas phase autoignition may occur in the recirculation zone just down stream of the platinum tube. The catalytic hydrogen micro-thruster developed in this study can self-sustain and provide a maximum thrust of 7 mN, which is suitable for precision attitude control of micro-and pico-satellites.

SEROLOGIC EVIDENCE OF EXPOSURE OF WILD MAMMALS TO FLAVIVIRUSES IN THE CENTRAL AND EASTERN UNITED STATES

Serosurveys were conducted to obtain flavivirus and West Nile virus (WNV) seroprevalence data from mammals. Sera from 513 small- and medium-sized mammals collected during late summer and fall 2003 from Colorado, Louisiana, New York, Ohio, and Pennsylvania were screened for flavivirus-specific antibodies. Sera samples containing antibody to flaviviruses were screened for WNV-specific antibodies by epitope-blocking enzyme-linked immunosorbent assays and confirmed with plaque reduction neutralization tests. Prevalence of WNV antibodies among study sites ranged from 0% to 42.8% among the mammal communities sampled. High prevalence rates for WNV were noted among raccoons (100%, with a very small sample size, N = 2), Virginia opossums (50.0%), fox squirrels (49.1%), and eastern gray squirrels (48.3%). The high WNV antibody prevalence noted for tree squirrels, the peri-domestic tendencies of several of these species, and their ease of observation could make these species useful sentinels for monitoring WNV activity within urban communities.

The Formation of Spikes in the Displacement of Miscible Fluids

We report on experiments in which a more viscous fluid displaces a less viscous one in a vertical cylindrical tube. These experiments were performed using silicone oils in a vertical pipette of small diameter. The more viscous fluid also had a slightly larger density than the less viscous fluid. In the initial configuration, the fluids were at rest, and the interface was nominally flat. A dye was added to the more viscous fluid for ease of observation of the interface between the fluids. The flow was initiated by pumping the more viscous fluid into the less viscous one. The displacement velocity was such that the Reynolds number was smaller than unity and the Peclet number for mass transfer between the fluids was large compared to unity. For upward displacement of the more viscous fluid from an initially stable configuration, an axisymmetric finger was observed under all conditions. However, a needle-shaped spike was seen to propagate from the main finger in many cases, similar to that observed by Petitjeans and Maxworthy for the displacement of a more viscous fluid by a less viscous one.

Development and Application of Electroluminescence Imaging for CdS/CdTe Characterization

AbstractA technique for spatially resolved optical characterization of CdS/CdTe thin film solar cells has been developed using electroluminescence (EL). In EL, excess minority carriers are injected via forward biasing. Light produced in radiative carrier recombination is collected with a CCD camera. Because EL intensity depends upon radiative vs. non-radiative recombination lifetimes, EL provides insight into material quality.Spatial resolution is a key benefit of EL as it provides insight into the non-uniformities of polycrystalline CdTe. At high magnification the resolution is diffraction limited, but coarser measurements of up to several millimeters in range may also be made. Non-uniformities in emission have been observed throughout this range.Further benefits of EL as a characterization technique are as follows: EL probes the region of most interest, namely the CdTe near the main junction. Also, it is observable at room temperature and data acquisition is fast. Finally, EL is observable at very low carrier injection rates, comparable to short circuit current. (Though more structure is often revealed at higher injection rates.) This low injection means that EL can be a non-destructive probe. This fact, along with the aforementioned ease of observation, means that EL could possibly be used for quality control and in situ testing of modules.Data gathered from CdS/CdTe cells from various institutions deposited using different methods such as close spaced sublimation, vapor transport, and sputtering are presented. In addition to changes in deposition technique, changes in processing parameters were observed to affect EL emission. Furthermore, overall EL emission decreased noticeably with stress at various biases and elevated temperature, with non-uniformity increasing in many cases. Changes in EL become apparent before changes in parameters acquired with standard current-voltage measurements, suggesting that this technique can be used as an early indicator for degrading cells. Finally, some dramatic changes in EL with stress suggest highly non-uniform degradation of the back contact.

Radial-slit erosion discharge

A new type of erosion discharge, which is distinguished by the stability of the formation and ease of observation of its nonequilibrium plasma in the form of radially propagating, solitary waves, is described.

Behaviour and performance of sows and piglets in crates and a Thorstensson system

There has been considerable concern over the welfare of sows housed in farrowing crates due to the severe restriction of movement this imposes upon them. A number of alternative systems have therefore been developed which allow sows greater freedom of movement. The aim of this study was to compare the behaviour and performance of sows housed in conventional crates with sows housed in a group-house Thorstensson system.A total of 18 Large White x Landrace sows were farrowed in crates or a group-housing Thorstensson system (balanced for parity and time of year). Two batches of seven were farrowed through the Thorstensson system of which five in each batch were selected for the current analysis (based on ease of observation). Thus a total of ten sows were analysed from the group-system (mean parity: 1.90 ± 0.40; 6 gilts). In addition eight sows were analysed from crates (mean parity 1.62 ± 0.26; 4 gilts).

Vertical Equilibrium of HI in the Galactic Disk

The analysis of vertical distribution and kinematics of disks of galaxies can yield the local mass density in the disk, distinct from the integrated mass inside a radius, derived from a rotation curve. HI is a particularly good tracer because of its ubiquity, ease of observation, and near isothermal nature. In the simplest case one considers the turbulent pressure gradient of the gas balancing the gravitational force in the z-direction. But the atomic gas may be subject to other pressures, for example, magnetic, cosmic ray or radiation pressure. The relative contributions of these are essentially unconstrained. The mass densities obtained from the analysis of HI vertical equilibrium can be verified with a similar analysis only in the solar neighborhood, where the vertical distribution and kinematics of stars can give an independent measure of the total midplane mass density (ρ0).

The effect of three different pesticides on soil protozoan activity

AbstractThree pesticides, dimethoate, pirimicarb and fenpropimorph, had a negative impact on the colonization of a sterilized soil by a natural population of soil protozoa. Fenpropimorph has an effect at the lowest concentration applied; 25 mg litre−1. Dimethoate reduced the soil respiration significantly for about 10 days after application. In single species cultures of soil protozoa in liquid media, a flagellate Cercomonas sp., was a better test organism than a ciliate, Colpoda sp., or an amoeba, Acanthamoeba sp., with respect to interpretation of dose‐response curves and ease of observation.

Microscopic studies of the magnetization-reversal process in Co-alloy thin films (abstract)

A quantitative study of the microscopic magnetization-reversal process in 250-Å thick Co, Co90Pt10, and Co88Cr12 films deposited on top of a 250-Å-thick Cr layer has been carried out. The entire structure was on a SiN membrane to allow ease of observation in the transmission electron microscope (TEM). The magnetization-reversal process was studied by using an electromagnet to saturate the film in one direction; the applied field was then reversed until the sample reached a magnetization state between +Mr and −Mr; the field was then reduced to zero and the sample taken to the TEM for observation of the resulting magnetic structure using Fresnel and DPC Lorentz microscopy.1 This process was repeated for a number of reversal fields ranging from zero to the loop closure field. This study shows that as the reversal field was increased from zero towards the coercivity, the magnetization dispersion, i.e., the range of angles between the local magnetization and the original saturation direction, increased. The local magnetization direction varied markedly from one region of the film to the next, indicating that it is strongly tied to the local anisotropy of the film. Once the steep part of the B-H loop is reached, small reversed regions are nucleated. These reversed regions consume the entire film by continued growth and nucleation as the reverse field is increased. The nucleation occurs at the same site when the magnetization is cycled around the B-H loop. This indicates that the local anisotropy determines the sites in which critical nuclei are formed in a given applied field. The boundary between the switched and unswitched regions consists of a complex magnetization vortex structure. Once the entire film has been switched, the local magnetization dispersion decreases as the reverse field is increased. Comparison of the results among the Co-alloy films will be discussed.

What farmers don't know can't help them: The strengths and weaknesses of indigenous technical knowledge in Honduras

Traditional Central American peasant farmers know more about some aspects of the local agroecosystem than about others. In general farmers know more about plants, less about insects, and less still about plant pathology. Without discounting economic factors, ease of observability must explain part of this difference. Certain local beliefs may affect what farmers observe and know. For example, a belief in spontaneous generation may lead people to fail to observe insect reproduction. The implications of the gaps in farmer knowledge are discussed in terms of the sustainable agriculture movement.

Cytogenetic techniques in mutagenicity testing.

Both in vivo and in vitro methodologies have uses as cytogenetic test systems for mutagenicity testing. The in vivo methods are certainly the choice as the primary test system, except perhaps in the case of viruses and some biologicals. When an in vitro method is used anaphase offers some advantages as greater speed and ease of observation, the detection of defects produced in G2 and mitosis, and the ability to distinguish between gaps and breaks, while it sacrifices the morphologic detail and ability to localize defects to specific chromosomes found in metaphase.