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Sample records for karstic aquifer bitter

  1. Opportunities to enhance management of karstic aquifers

    NASA Astrophysics Data System (ADS)

    Parizek, Richard R.

    2007-01-01

    Methods exist to obtain “new sources of water.” Examples include: (1) capturing and enhancing stormwater recharge and retention within diffuse-flow portions of karst and other aquifers; (2) recycling and reuse of waste water; (3) reducing evapotranspiration and rejected recharge; and (4) ameliorating atmospheric acid deposition through use of alkaline groundwater. These little used management methods have immense potential to sustain future water demands. Full utilization of “new” and traditional water resources requires an understanding of the hydrogeologic framework of karstic aquifers. Reliable conceptual, numerical flow and transport models are needed to help evaluate, select, and design viable water management options. Three such simulation examples are provided together with a discussion of Penn State’s Wastewater reuse project where recharge approaches 3.785 × 109l/year

  2. Estimating preferential flow in karstic aquifers using statistical mixed models.

    PubMed

    Anaya, Angel A; Padilla, Ingrid; Macchiavelli, Raul; Vesper, Dorothy J; Meeker, John D; Alshawabkeh, Akram N

    2014-01-01

    Karst aquifers are highly productive groundwater systems often associated with conduit flow. These systems can be highly vulnerable to contamination, resulting in a high potential for contaminant exposure to humans and ecosystems. This work develops statistical models to spatially characterize flow and transport patterns in karstified limestone and determines the effect of aquifer flow rates on these patterns. A laboratory-scale Geo-HydroBed model is used to simulate flow and transport processes in a karstic limestone unit. The model consists of stainless steel tanks containing a karstified limestone block collected from a karst aquifer formation in northern Puerto Rico. Experimental work involves making a series of flow and tracer injections, while monitoring hydraulic and tracer response spatially and temporally. Statistical mixed models (SMMs) are applied to hydraulic data to determine likely pathways of preferential flow in the limestone units. The models indicate a highly heterogeneous system with dominant, flow-dependent preferential flow regions. Results indicate that regions of preferential flow tend to expand at higher groundwater flow rates, suggesting a greater volume of the system being flushed by flowing water at higher rates. Spatial and temporal distribution of tracer concentrations indicates the presence of conduit-like and diffuse flow transport in the system, supporting the notion of both combined transport mechanisms in the limestone unit. The temporal response of tracer concentrations at different locations in the model coincide with, and confirms the preferential flow distribution generated with the SMMs used in the study.

  3. Estimating Preferential Flow in Karstic Aquifers Using Statistical Mixed Models

    PubMed Central

    Anaya, Angel A.; Padilla, Ingrid; Macchiavelli, Raul; Vesper, Dorothy J.; Meeker, John D.; Alshawabkeh, Akram N.

    2013-01-01

    Karst aquifers are highly productive groundwater systems often associated with conduit flow. These systems can be highly vulnerable to contamination, resulting in a high potential for contaminant exposure to humans and ecosystems. This work develops statistical models to spatially characterize flow and transport patterns in karstified limestone and determines the effect of aquifer flow rates on these patterns. A laboratory-scale Geo-HydroBed model is used to simulate flow and transport processes in a karstic limestone unit. The model consists of stainless-steel tanks containing a karstified limestone block collected from a karst aquifer formation in northern Puerto Rico. Experimental work involves making a series of flow and tracer injections, while monitoring hydraulic and tracer response spatially and temporally. Statistical mixed models are applied to hydraulic data to determine likely pathways of preferential flow in the limestone units. The models indicate a highly heterogeneous system with dominant, flow-dependent preferential flow regions. Results indicate that regions of preferential flow tend to expand at higher groundwater flow rates, suggesting a greater volume of the system being flushed by flowing water at higher rates. Spatial and temporal distribution of tracer concentrations indicates the presence of conduit-like and diffuse flow transport in the system, supporting the notion of both combined transport mechanisms in the limestone unit. The temporal response of tracer concentrations at different locations in the model coincide with, and confirms the preferential flow distribution generated with the statistical mixed models used in the study. PMID:23802921

  4. Groundwater-flow modeling in the Yucatan karstic aquifer, Mexico

    NASA Astrophysics Data System (ADS)

    González-Herrera, Roger; Sánchez-y-Pinto, Ismael; Gamboa-Vargas, José

    2002-09-01

    The current conceptual model of the unconfined karstic aquifer in the Yucatan Peninsula, Mexico, is that a fresh-water lens floats above denser saline water that penetrates more than 40 km inland. The transmissivity of the aquifer is very high so the hydraulic gradient is very low, ranging from 7-10 mm/km through most of the northern part of the peninsula. The computer modeling program AQUIFER was used to investigate the regional groundwater flow in the aquifer. The karstified zone was modeled using the assumption that it acts hydraulically similar to a granular, porous medium. As part of the calibration, the following hypotheses were tested: (1) karstic features play an important role in the groundwater-flow system; (2) a ring or belt of sinkholes in the area is a manifestation of a zone of high transmissivity that facilitates the channeling of groundwater toward the Gulf of Mexico; and (3) the geologic features in the southern part of Yucatan influence the groundwater-flow system. The model shows that the Sierrita de Ticul fault, in the southwestern part of the study area, acts as a flow barrier and head values decline toward the northeast. The modeling also shows that the regional flow-system dynamics have not been altered despite the large number of pumping wells because the volume of water pumped is small compared with the volume of recharge, and the well-developed karst system of the region has a very high hydraulic conductivity. Résumé. Le modèle conceptuel classique de l'aquifère karstique libre de la péninsule du Yucatan (Mexique) consiste en une lentille d'eau douce flottant sur une eau salée plus dense qui pénètre à plus de 40 km à l'intérieur des terres. La transmissivité de l'aquifère est très élevée, en sorte que le gradient hydraulique est très faible, compris entre 7 et 10 mm/km dans la plus grande partie du nord de la péninsule. Le modèle AQUIFER a été utilisé pour explorer les écoulements souterrains régionaux dans cet

  5. Estimating ground water recharge using flow models of perched karstic aquifers.

    PubMed

    Weiss, Menachem; Gvirtzman, Haim

    2007-01-01

    The fraction of rain that is annually recharged to ground water is a function of the transient quantities of precipitation (wet vs. dry years) as well as other meteorological and geologic factors, and thus it is very difficult to estimate. In this study, we have used long records (20 to 30 years) of precipitation and spring discharge to reconstruct the transient character of yearly recharge. These data sets were used to calibrate numerical ground water flow models on the less than 3 km(2) scale for four separate perched karstic aquifers in the Judean and Samarian Mountains of Israel. The stratification and karstic character of the local carbonate rock aquifers cause ground water to flow through discrete dissolution channels and to discharge at isolated springs. An innovative, dual-porosity approach was used where a finite-difference solution simulates flow in the rock matrix, while the karstic channels are simulated using computationally simple drains. Perched conditions are also simulated innovatively using MODFLOW by treating the bottom unsaturated layer as if it is saturated, but by assuming zero pressure head throughout the "unsaturated" layer. Best fitting between measured and computed spring hydrograph data has allowed us to develop a set of empirical functions relating measured precipitation to recharge to the aquifer. The generic methodology presented gives insight into the suspected changes in aquifer recharge rates between particularly wet or dry years.

  6. Elucidation of denitrification mechanism in karstic Ryukyu limestone aquifer

    NASA Astrophysics Data System (ADS)

    Hijikawa, K.

    2014-12-01

    Nitrate (NO3-) concentrations in public water supplies have risen above acceptable levels in many areas of the world including Japan, largely as a result of contamination by human and animal waste and overuse of fertilizers. A previous study has characterized nitrate concentrations in groundwater in this area is a higher than the upper value (44mgL-1) of environmental quality criteria on one hands. On the other hand, there exists points where the concentration of nitric acid is not detected, which suggests the possibility of denitrification. During early 2000, a new analytical procedure for nitrate isotopic measurement, termed the "denitrifier method", was established. With the development of the nitrate isotope tracer method, much research has been reported detailing sources of groundwater nitrate and denitrification mechanisms. This study presents a pilot case study (in the southern part of Okinawa Main Island, Japan, where Ryukyu limestone is extensively distributed) using the combined stable isotope ratios of major elements (C, N and S) as net recorders of the biogeochemical reactions with the aim of elucidation of denitrification mechanism in Ryukyu limestone aquifer. As a result, significant decreases in nitrate concentrations due to denitrification were observed in groundwater at some locations, which induced increases in isotope ratios up to 59.7‰ for δ15NNO3. These points of groundwater were located above the cutoff wall of the underground dam and near the fault. It is considered that the residence time of the groundwater is longer than the other points at these denitrification points, and that reduction condition tends to be formed in the groundwater. However, the rapid rise of the groundwater level due to rainfall is likely to occur in the Ryukyu limestone aquifer, where the ground water was found to have changed dynamically from the reduction condition to the oxidation condition which a denitrification (has not occured)does not occur. Moreover, the

  7. Tracking the multiple origins of salinity in three different karstic aquifers (southern France): Sr isotopes constraints.

    NASA Astrophysics Data System (ADS)

    Le Gal La Salle, Corinne; Khaska, Mahmoud; Lancelot, Joël

    2014-05-01

    Groundwater resources of the Mediterranean area are submitted to a high anthropic pressure and face a set of major climatic and geological constraints. The potential exploitation of karst aquifers is still unclear and probably underestimated, but their vulnerability to pollution is high and potential for salinization in coastal aquifer increases with over exploitation and the rise of sea level. In order to trace the origin of salinity in karst aquifers in a Mediterranean coastal environment, a multi-tracer approach coupling major, specific trace elements and stable (δ18O, δ2H) and radiogenic (87Sr/86Sr) isotopes was held. Three close sites in southern France have been studied to investigate a different origin of the salinity. In the coastal karst aquifer of la Clape (Aude), salinity originated from deep salt water due to a paleoseawater intrusion followed by water-rock interaction with the carbonate host rock. On land and off-shore, powerful tertiary sedimentary deep deposits limit the karst network communications with the seawater. The presence of many faults could be a contributing factor to the mixing of salt water within the karst water. There it was shown that the paleoseawater proportions in the aquifer ranged from 0 to 16 %. Slightly further inland, in another similar karstic aquifer, the source of Oeillal (Aude) displayed a high salinity. Salinity most surely originated from deep horizons that come to the surface by a major normal fault where it mixes with karst waters. Deep brines from ancient meteoric water evolved by water-rock interaction with evaporites in the underlying Keuper formation. There calculated proportions of salt water into the mixture with karst water varied between 30 and 40%. In the third site located on the edge of the seawater shoreline, the simple limestone karst aquifer of Pliocene in Frontignan (Hérault) was under increasing salinity intrusion of seawater, which proportions of mixing between seawater and karst water varied from 2

  8. A combined methodology of vulnerability mapping and groundwater flow models for the management of karstic aquifers

    NASA Astrophysics Data System (ADS)

    Kavouri, Konstantina; Karatzas, George; Plagnes, Valérie; Varouchakis, Emmanouil

    2013-04-01

    The present study examines the application of a distributed flow model to a typical Mediterranean karstic aquifer and the importance of the input information. The site of interest is located at the eastern part of Crete and extends to an area of 167 km² mainly of coverless limestone. The geological and climatic conditions of the area are representative of the Mediterranean karst. Also, the information on geological and hydrological characteristics is limited, which is also very common for these systems. The developed model is a combination of the Equivalent Porous Continuum with Discrete Fractures (EPC-DF) modeling approach and the GIS-based vulnerability mapping method PaPRIKa. The EPC-DF method is commonly used for the simulation of systems characterized by dual porosity. In the present study the karstic system is represented by a porous aquifer which also has a principal drainage axe. The model is developed using the finite element code FEFLOW (WASY) which allows for the integration of discrete features such as channels in a porous matrix. The PaPRIKa method is a multi-criteria cartographic method for the evaluation of intrinsic vulnerability of karstic systems, which considers four criteria: the existence of a Protection cover (P map), the lithological properties of the Reservoir (R map), the duality of Infiltration (I map) and the degree of Karstification (Ka map). It spatially describes both structural and functioning characteristics of the karst, providing a simple and realistic conceptual scheme. In the developed model the distribution of the parameters follows the cartographic limits provided by i) the P and I maps for the assignment of recharge, and ii) the R and Ka maps for the assignment of the hydraulic parameters of the saturated zone. The obtained simulated results of groundwater levels are in a good agreement with the selected field measurements. The overall aim of the present study is the development of a flexible tool for the management of water

  9. Electrical Resistivity Tomography of the Karstic Aquifer of Bittit spring (Middle Atlas, Morocco)

    NASA Astrophysics Data System (ADS)

    Qarqori, Kh.; Rouai, M.; Moreau, F.; Saracco, G.; Hermitte, D.; Boualoul, M.; Dauteuil, O.; Biessy, G.; Sahbi, H.

    2009-04-01

    The Tabular Middle Atlas reservoir is one of the most important aquifers in northern Morocco. It is mainly a water table fractured reservoir consisting of Lias limestone and dolomite. The matrix permeability is very low and water flows essentially along open fractures and karsts. The Bittit Spring belongs to this karstic system and constitutes an important aquifer lying at the junction between the tabular reservoir and the Sais basin. Bittit spring, with an average annual discharge of about 1600 l/s, contributes largely to water supply of the big city of Meknes. Groundwater circulation is complex due to tectonics and to presence of karstic Quaternary travertine overlying Lias carbonate. In Bittit area, travertine is mostly covered by Quaternary basalt. Up to now water flow paths and the underground karst organization remain misknown, and turbidity affects the water quality after rain events. To highlight these issues, an integrated geophysical survey was performed in this area in the framework of a French-Moroccan scientific project. The geophysical imaging was carried out mainly by Electrical Resistivity Tomography (ERT). Resistivity data were acquired by an ABEM Terrameter SAS1000 and a multi-electrode Lund system imaging using a Wenner array configuration of 64 electrodes and 5m spacing, reaching a depth of about 50m. Topographic corrections and 2D inversion models were performed using Res2Dinv software package. Seven 2D resistivity high resolution images have been obtained allowing to detect, delineate important fractures and also to hydrogeological characterization of the underground karst. A borehole of 100m depth was drilled in order to correlate and calibrate geophysical data and proposed models. Two sub-vertical fracture families have been identified with NE-SW and NW-SE directions respectively. These results correlate well with fracture data analysis gathered from remote sensing Spot images at large scale, and from local field fracture scanline surveys. A

  10. The Investigation of Mass Transfer in the Karasu Karstic Aquifer, Konya, Turkey

    NASA Astrophysics Data System (ADS)

    Ozdemir, Adnan; Nalbantcilar, Tahir

    2002-09-01

    In this study, the changes in the chemical composition of the groundwater along a flow path were examined by using the water samples collected from unconfined, semi-confined and confined parts of the Karasu karstic aquifer. It was determined that transport of bicarbonate, calcium, and magnesium was dominant in unconfined and semi-confined parts of the aquifer, whereas calcite and dolomite precipitate in the confined parts. On the other hand, gypsum dissolution is present in all parts of the aquifer. In addition, the computed saturation indices explain the occurrences and precipitation of travertines in the Goksu Valley, which is the discharge area for the aquifer. Résumé. Les modifications de la composition chimique de l'eau souterraine le long d'un axe d'écoulement ont été étudiées à partir d'échantillons prélevés dans les parties libres, semi-captives et captives de l'aquifère karstique de Karasu. On a mis en évidence que le transport de carbonate, de calcium et de magnésium est prépondérant dans les parties libres et semi-captives de l'aquifère, alors que la calcite et la dolomite précipitent dans les parties captives. En outre, la dissolution du gypse se produit dans toutes les parties de l'aquifère. Par ailleurs, les indices de saturation calculés rendent compte de l'existence et de la précipitation des travertins dans la vallée du Göksu, qui est la zone de décharge de cet aquifère. Resumen. En este estudio, se han examinado los cambios de composición química en las aguas subterráneas a lo largo de una línea de corriente mediante el análisis de muestras recogidas en partes libres, semiconfinadas y cautivas del acuífero cárstico de Karasu. Se ha determinado que el transporte de bicarbonato, calcio y magnesio es dominante en las zonas libres y semiconfinadas, mientras que la calcita y la dolomita precipitan en las zonas confinadas. Por otro lado, la disolución de yesos ocurre en todo el ámbito del acuífero. Además, los

  11. Assessing the flow regime in a contaminated fractured and karstic dolostone aquifer supplying municipal water

    NASA Astrophysics Data System (ADS)

    Perrin, Jérôme; Parker, Beth L.; Cherry, John A.

    2011-04-01

    SummaryThe Silurian dolostone bedrock in Ontario, Canada, is a broad 400 km long swath northward from Niagara Falls through the Bruce Peninsula that represents an important water source for municipal, industrial, and agricultural uses. Where the Quaternary overburden is thin or absent, karst is common. This study concerns an urban area where the dolostone aquifer is 100 m thick beneath up to 50 m thick Quaternary deposits and where karst features identified by borehole information are common. Hydraulic tests show moderate to large bulk rock hydraulic conductivity and rock core tests indicate much smaller matrix hydraulic conductivity than the bulk rock values. Therefore, the aquifer is essentially a dual permeability, fully saturated system in which conduits occur within a network of ubiquitous extensive, horizontally- and vertically-interconnected fractures. Karst features are concentrated in a thin zone at the top-of-rock, likely representing former epikarst, and also in a thicker zone in the middle of the aquifer. Some pumping test results and large yields of some municipal wells are consistent with conduit occurrences. However, atmospheric tritium, distributed-source contamination (Cl -, NO3-), and a point-source pesticide plume (metolachlor) show detailed concentration distributions lacking influence of flow in conduits. Detailed hydraulic head profiles also show no influence of conduit flow. This study shows that when designing monitoring networks for groundwater quality and source water protection in similar contexts, locating conduits is not necessary because contaminant distributions are governed by the combined influences of the rock matrix, fractures and conduits, the hydraulic boundary conditions, and the interconnected fracture network with only minimal conduit effects. Prior to glaciations, an integrated karstic aquifer could develop with flow controlled by conduits; however, this original, converging flow system became non-functional when the

  12. Numerical model to support the management of groundwater resources of a coastal karstic aquifer (southern Italy)

    NASA Astrophysics Data System (ADS)

    Polemio, Maurizio; Romanazzi, Andrea

    2013-04-01

    The main purpose of the research is to define management apporouches for a coastal karstic aquifer. The core of the tools uses numerical modelling, applied to groundwater resource of Salento (southern Italy) and criteria to reduce the quantitative and qualitative degradation risks. The computer codes selected for numerical groundwater modelling were MODFLOW and SEAWAT. The approach chosen was based on the concept of a equivalent homogeneous porous medium by which it is assumed that the real heterogeneous aquifer can be simulated as homogeneous porous media within cells or elements. The modelled aquifer portion extends for 2230 km2, and it was uniformly discretized into 97,200 cells, each one of 0.6 km2. Vertically, to allow a good lithological and hydrogeological discretization, the area was divided into 12 layers, from 214 to -350 m asl. Thickness and geometry of layers was defined on the basis of the aquifer conceptualisation based on the 3d knowledge of hydrogeological complexes. For the boundary conditions, inactive cells were used along the boundary with the rest of Murgia-Salento aquifer, as conceptual underground watershed due to the absence of flow. About the sea boundary was used CHD boundary cells (Constant Head Boundary). Additional boundary conditions were used for SEAWAT modelling, as initial concentration and constant concentration, in the latter case for cells shaping the coastline. A mean annual net rainfall (recharge) was calculated in each cell with a GIS elaboration, ranged from 68 to 343 mm, 173 mm an average. The recharge or infiltration was calculated using an infiltration coefficient (IC) (defined as infiltration/net rainfall ratio) for each hydrogeological complex, assuming values equal to 1 inside endorheic areas. The mean annual recharge was equal to 150 mm. The model was implemented using MODFLOW and SEAWAT codes in steady-state conditions to obtain a starting point for following transient scenarios, using piezometric data of thirties as

  13. Vulnerability of a public supply well in a karstic aquifer to contamination

    USGS Publications Warehouse

    Katz, B.G.; McBride, W.S.; Hunt, A.G.; Crandall, C.A.; Metz, P.A.; Eberts, S.M.; Berndt, M.P.

    2009-01-01

    To assess the vulnerability of ground water to contamination in the karstic Upper Floridan aquifer (UFA), age-dating tracers and selected anthropogenic and naturally occurring compounds were analyzed in multiple water samples from a public supply well (PSW) near Tampa, Florida. Samples also were collected from 28 monitoring wells in the UFA and the overlying surficial aquifer system (SAS) and intermediate confining unit located within the contributing recharge area to the PSW. Age tracer and geochemical data from the earlier stage of the study (2003 through 2005) were combined with new data (2006) on concentrations of sulfur hexafluoride (SF6), tritium (3H), and helium-3, which were consistent with binary mixtures of water for the PSW dominated by young water (less than 7 years). Water samples from the SAS also indicated mostly young water (less than 7 years); however, most water samples from monitoring wells in the UFA had lower SF6 and 3H concentrations than the PSW and SAS, indicating mixtures containing high proportions of older water (more than 60 years). Vulnerability of the PSW to contamination was indicated by predominantly young water and elevated nitrate-N and volatile organic compound concentrations that were similar to those in the SAS. Elevated arsenic (As) concentrations (3 to 19 ??g/L) and higher As(V)/As(III) ratios in the PSW than in water from UFA monitoring wells indicate that oxic water from the SAS likely mobilizes As from pyrite in the UFA matrix. Young water found in the PSW also was present in UFA monitoring wells that tap a highly transmissive zone (43- to 53-m depth) in the UFA. ?? 2008 National Ground Water Association.

  14. Use of microbial analysis to evaluate denitrification in the karstic aquifer of Okinawa, Japan

    NASA Astrophysics Data System (ADS)

    Yasumoto, J.

    2014-12-01

    Denitrification, a microbial process in the nitrogen cycle, is a facultative respiratory pathway in which nitrate (NO3-), nitrite (NO2-), nitric oxide (NO), and nitrous oxide (N2O), successively, are reduced to nitrogen gas (N2). This study explores the use of microbial analysis to evaluate the processes involved in nitrate attenuation in groundwater. Polymerase chain reaction (PCR)-denaturing gradient gel electrophoresis (DGGE) is used to identify denitrifiers based only on their 16SrRNA gene sequences, and Real-Time PCR analysis is used to quantify nitrite reducing genes (nirK and nirS), this suggest that a new methods for detecting denitrification activity by comparing the gene dosage that has been detected by RT-PCR and the value of the δ15NNO3- and δ18ONO3-. This study focuses on a zone of significant NO3- attenuation occurring at underground dam catchment area in the karstic Ryukyu limestone aquifer, which is located southern part of Okinawa, Japan. As a result of microbial analysis, the bacteria were detected at all observation points which have been reported to have denitrification ability. And it has been confirmed that the bacteria has a gene nirS which is related to denitrification. In addition, many bacteria related to denitrification have been extracted from suspended solids more than from groundwater in the aquifer. And, the correlation was high between nirK /nirS gene dosage that has been detected by RT-PCR and the value of the δ15N and δ18O; therefore, this study demonstrates the effectiveness of using Real-Time PCR analysis for providing insights into the processes affecting nitrate attenuation in ground water.

  15. Chemical and biological tracers to determine groundwater flow in karstic aquifer, Yucatan Peninsula

    NASA Astrophysics Data System (ADS)

    Lenczewski, M.; Leal-Bautista, R. M.; McLain, J. E.

    2013-05-01

    Little is known about the extent of pollution in groundwater in the Yucatan Peninsula; however current population growth, both from international tourism and Mexican nationals increases the potential for wastewater release of a vast array of contaminants including personal care products, pharmaceuticals (Rx), and pathogenic microorganisms. Pathogens and Rx in groundwater can persist and can be particularly acute in this region where high permeability of the karst bedrock and the lack of top soil permit the rapid transport of contaminants into groundwater aquifers. The objective of this research is to develop and utilize novel biological and chemical source tracking methods to distinguish between different sources of anthropogenic pollution in degraded groundwater. Although several methods have been used successfully to track fecal contamination sources in small scale studies, little is known about their spatial limitations, as source tracking studies rarely include sample collection over a wide geographical area and with different sources of water. In addition, although source tracking methods to distinguish human from animal fecal contamination are widely available, this work has developed source tracking distinguish between separate human populations is highly unique. To achieve this objective, we collected water samples from a series of drinking wells, cenotes (sinkholes), wastewater treatment plants, and injection wells across the Yucatan Peninsula and examine potential source tracers within the collected water samples. The result suggests that groundwater sources impacted by tourist vs. local populations contain different chemical stressors. This work has developed a more detailed understanding of the presence and persistence of personal care products, pharmaceuticals, and fecal indicators in a karstic system; such understanding will be a vital component for the protection Mexican groundwater and human health. Quantification of different pollution sources

  16. Characterization of groundwater dynamics in an heterogeneous karstic aquifer through active and passive Fiber Optic DTS methods

    NASA Astrophysics Data System (ADS)

    Bour, Olivier; Le Lay, Hugo; Lavenant, Nicolas; Simon, Nataline; Bodin, Jacques; Guihéneuf, Nicolas; Nauleau, Benoit; Porel, Gilles; Le Borgne, Tanguy

    2016-04-01

    Temperature has been proposed as an excellent tracer for monitoring groundwater flows, especially in karstic aquifers which are characterized by rapid and localized flows. Here, we present some experiments that demonstrate the interest of passive and active Fiber-Optic Distributed Temperature Sensing (FO-DTS) for characterizing heterogeneities and groundwater dynamics in a karstic aquifer. The experimental tests were achieved at the Poitiers Experimental Hydrogeological Site (SEH) where groundwater flows are mainly associated with sub-horizontal karstic structures and sub-vertical fractures. The site consists in 35 boreholes drilled within a regular 210 x 210 m grid, and having an average depth of about 125 meters (http://hplus.ore.fr). The simplest experiments consist in monitoring temperature changes simultaneously in 3 to 4 boreholes during a pumping test. The duration of each pumping test was about 3 to 4 h, a duration that allowed obtaining a clear hydraulic response on most boreholes. Temperature was monitored every 30 seconds with a temperature resolution varying between 0.02°C to 0.05°C for a spatial resolution equal either to 29 cm or 50 centimeters depending on the DTS unit. As expected, the changes in temperature are highly variable from well to well. In most boreholes, one clearly observes some changes of borehole temperature that may be used to locate precisely the main permeable levels and to estimate borehole flow rates through the borehole temperature evolution. When no temperature changes are observed, active DTS methods may still allow monitoring of groundwater flows. Active-DTS methods are considered when the cable or borehole fluid is heated. For instance, it is possible to use a thermal resistance within a borehole and monitor fluid movement through temperature evolution with time. Thus, passive and active DTS methods are found very complementary for providing spatial and temporal monitoring of groundwater dynamics in heterogeneous aquifers.

  17. Geodesic and hydrogeophysic long term observations in the Durzon karstic aquifer (Larzac, France)

    NASA Astrophysics Data System (ADS)

    Le Moigne, Nicolas; Bayer, Roger; Boudin, Frederick; Champollion, Cedric; Chery, Jean; Collard, Philippe; Daignières, Marc; Deville, Sabrina; Doerflinger, Erik; Vernant, Philippe

    2010-05-01

    Karsts are generally characterized by high heterogeneity at all scales for both the water storage properties and the mode of water transport. The Durzon karst system is located in south of France and is characterized by a unsaturated zone of 100-150 m width. The water input is exclusively rainfall and draining occurs at the Durzon perennial spring in a karstic valley. The Durzon aquifer has been monitored by our group by different geophysical methods (gravimetry, tiltmetry, more details below) for several years. The present-day stage of the project is to setup long term observations to assess hydrological properties of the karst in a small area of 500m*500m with numerous caves (up to 100 m deep and more than 2 km of development). The observations are of four major types: - Continuous high frequency and high accuracy gravimetry: Gravimetric observations can be directly linked to the variations of water masses in the unsaturated zone. The iGrav™ Superconducting Gravity Meter from GWR (San Diego, USA) will be used to record continuous gravity variations and track water mass variations at a few millimeters level. The iGrav™ is a new SG model from GWR that has been simplified for portable and field operation, but retains the stability and precision of previous SGs. With a drift rate of less than 0.5 microGal/month and a virtually constant scale factory, the iGrav™ will provide a much higher stability and precision than can be achieved with mechanical spring-type gravity meters. - Water flux measurements (atmospheric and in-situ): A flux tower provides evapo-transpiration measurements (output) allowing complete budget calculation with the help of gravity (storage variations) and rainfall (input). An original measurement corresponds to the measure of the in-situ flow inside karstic caves (stalactites and underground river). - Tiltmetry: In situ (in caves) measurements are completed by long base silica tiltmeters. Tiltmeters are sensible to water storage in fractures

  18. Turbidity and nitrate transfer in karstic aquifers in rural areas: the Brionne Basin case-study.

    PubMed

    Nebbache, S; Feeny, V; Poudevigne, I; Alard, D

    2001-08-01

    The degradation of water quality in many groundwaters of Europe is a major source of concern. Rises in turbidity and nitrate concentrations represent present or potential threats for the quality of drinking water in rural areas. They are for the most part a consequence of agricultural intensification which has considerably affected land cover and land use in recent decades. In our case-study (a karstic catchment) the mechanisms which explain changes in water quality, as far as turbidity and nitrate are concerned, result from a strong continuity between surface and underground waters. The karstic system of the Brionne Basin can be considered as both the focus of rapid horizontal flows (runoff, a rapid process in which rainwater reaches the spring directly through sinkholes) and slow vertical flows (leaching, in which rainwater filters through the soil to the spring). A hierarchical approach to the water pollution problem of the basin suggests that turbidity or nitrate concentrations peak during heavy rain episodes and are short-term events. In terms of management, this implies that the solution to water pollution caused by such events is also short-term and can therefore be addressed at a local scale. The rise of nitrate concentrations during the past twenty years is the main concern. The solution can only be found at a global scale (all the catchment area must be taken in account: land plots and their spatial configuration), and by taking a long-term approach.

  19. Modeling the hydraulical behavior of a fissured-karstic aquifer in exploitation conditions

    NASA Astrophysics Data System (ADS)

    Debieche, T. H.; Guglielmi, Y.; Mudry, J.

    2002-02-01

    A 5-year daily measurement of the dynamic level in a borehole was plotted versus cumulative yield since the beginning of exploitation. Eighty percent of the experimental curve is explained by a linear function ( h= aQc+ h0) by intervals. Only floods, which follow heavy storms and non-pumping cannot be taken into account. The slopes of the straight lines are spread around two constant values of the slope: a r=+0.35×10 -3 m m -3, which characterizes the part which is controlled by recharge, and a p=-0.14× 10 -3 m m -3, which characterizes the draining part of the aquifer fractures. This linear fitting demonstrates that the borehole-aquifer system can be considered as an equivalent continuous medium, where the linear relationship between dynamic head and pumped yield are defined by the values of ar and ap. Thus the hydraulic behavior of the aquifer differs according to the pumping rate: equivalent continuous medium for a low rate, dual permeability for a high one. This work demonstrates that the long-term behavior of an exploited fissured aquifer can be described by a simple model, if the duration of the aquifer test is long enough (1-3 months). It also shows that the production phase must include repetitive head measurements in order to refine the exploitation yield and the management conditions.

  20. Transport of suspended solids from a karstic to an alluvial aquifer: The role of the karst/alluvium interface

    USGS Publications Warehouse

    Massei, N.; Lacroix, M.; Wang, H.Q.; Mahler, B.J.; Dupont, J.P.

    2002-01-01

    This study focuses on the coupled transport of dissolved constituents and particulates, from their infiltration on a karst plateau to their discharge from a karst spring and their arrival at a well in an alluvial plain. Particulate markers were identified and the transport of solids was characterised in situ in porous and karstic media, based on particle size analyses, SEM, and traces. Transport from the sinkhole to the spring appeared to be dominated by flow through karst: particulate transport was apparently conservative between the two sites, and there was little difference in the overall character of the particle size distribution of the particulates infiltrating the sinkhole and of those discharging from the spring. Qualitatively, the mineralogy of the infiltrating and discharging material was similar, although at the spring an autochthonous contribution from the aquifer was noted (chalk particles eroded from the parent rock by weathering). In contrast, transport between the spring and the well appears to be affected by the overlying alluvium: particles in the water from the well, showed evidence of considerable size-sorting. Additionally, SEM images of the well samples showed the presence of particles originating from the overlying alluvial system; these particles were not found in samples from the sinkhole or the spring. The differences between the particulates discharging from the spring and the well indicate that the water pumped from the alluvial plain is coming from the karst aquifer via the very transmissive, complex geologic interface between the underlying chalk formation and the gravel at the base of the overlying alluvial system. ?? 2002 Elsevier Science B.V. All rights reserved.

  1. Analysing Submarine Groundwater Discharge (SGD)-borne Dissolved Organic Matter (DOM) in a karstic aquifer, Co. Galway, Ireland.

    NASA Astrophysics Data System (ADS)

    Kelly, Tara; Rocha, Carlos

    2014-05-01

    Submarine Groundwater Discharge (SGD) constitutes an "invisible" link between land and sea, transporting allochthonous and autochthonous dissolved organic matter (DOM), nutrients and metals to the ocean via the subterranean estuary. The latter acts as a powerful bioreactor where groundwater, in transit from land to sea, mixes with seawater leading to active modulation of both DOM content and chemical makeup of SGD. DOM in freshwater systems is a key component of the global carbon cycle. Climate change may hence increase the concentration of allochthonous carbon entering the oceans as terrestrial DOC is released from soils at higher temperatures, and transported via SGD. Presently, little is known about the effects of SGD-borne DOM on coastal carbon cycling. SGD therefore represents a dynamic reservoir and analysis is critical to forecast future environmental management programmes, both on a local and global scale. Labile DOM plays a crucial role in microbial remineralisation processes, and as it breaks down it contributes to the groundwater nutrient pool. Locally, this could add to eutrophication. However, if refractory carbon is present, it will be recalcitrant to mineralisation in transit and at the subterranean estuary. This putative additional input will thus imply the contribution of SGD to oceanic carbon storage. This study is focused on Kinvara Bay (Galway, western Ireland), the focal point for waters discharging from the Gort-Kinvara karstic aquifer. This aquifer represents the ideal study location for evaluation of SGD contribution to the coastal DOM pool, as SGD is focused in the bay, surface drainage is very limited, and groundwater travels across a large catchment area with a short residence time, minimising DOM modification in transit. DOM samples collected in the field have been analysed using Three-Dimensional Excitation Emission Matrix Fluorescence (3D-EEMF) and High Temperature Catalytic Oxidation. PARAFAC is subsequently used as a tool to

  2. Denitrification and inference of nitrogen sources in the karstic Floridan Aquifer

    USGS Publications Warehouse

    Heffernan, J.B.; Albertin, A.R.; Fork, M.L.; Katz, B.G.; Cohen, M.J.

    2011-01-01

    Aquifer denitrification is among the most poorly constrained fluxes in global and regional nitrogen budgets. The few direct measurements of denitrification in groundwaters provide limited information about its spatial and temporal variability, particularly at the scale of whole aquifers. Uncertainty in estimates of denitrification may also lead to underestimates of its effect on isotopic signatures of inorganic N, and thereby confound the inference of N source from these data. In this study, our objectives are to quantify the magnitude and variability of denitrification in the Upper Floridan Aquifer (UFA) and evaluate its effect on N isotopic signatures at the regional scale. Using dual noble gas tracers (Ne, Ar) to generate physical predictions of N2 gas concentrations for 112 observations from 61 UFA springs, we show that excess (i.e. denitrification-derived) N2 is highly variable in space and inversely correlated with dissolved oxygen (O2). Negative relationship between O2 and ??15NNO 3 across a larger dataset of 113 springs, well-constrained isotopic fractionation coefficients, and strong 15N: 18O covariation further support inferences of denitrification in this uniquely organic-matter-poor system. Despite relatively low average rates, denitrification accounted for 32% of estimated aquifer N inputs across all sampled UFA springs. Back-calculations of source ??15NNO 3 based on denitrification progression suggest that isotopically-enriched nitrate (NO3-) in many springs of the UFA reflects groundwater denitrification rather than urban- or animal-derived inputs. ?? Author(s) 2011.

  3. Microgravity methods for characterization of groundwater-storage changes and aquifer properties in the karstic Madison aquifer in the Black Hills of South Dakota, 2009-12

    USGS Publications Warehouse

    Koth, Karl R.; Long, Andrew J.

    2012-01-01

    A study of groundwater storage in the karstic Madison aquifer in the Black Hills of South Dakota using microgravity methods was conducted by the U.S. Geological Survey in cooperation with West Dakota Water Development District, South Dakota Department of Environment and Natural Resources, and Lawrence County. Microgravity measurements from 2009 to 2012 were used to investigate groundwater-storage changes and effective porosity in unconfined areas of the Madison aquifer. Time-lapse microgravity surveys that use portable high-sensitivity absolute and relative gravimeters indicated temporal-gravity changes as a result of changing groundwater mass. These extremely precise measurements of gravity required characterization and removal of internal instrumental and external environmental effects on gravity from the raw data. The corrected data allowed groundwater-storage volume to be quantified with an accuracy of about plus or minus 0.5 foot of water per unit area of aquifer. Quantification of groundwater-storage change, coupled with water-level data from observation wells located near the focus areas, also was used to calculate the effective porosity at specific altitudes directly beneath gravity stations. Gravity stations were established on bedrock outcrops in three separate focus areas for this study. The first area, the Spring Canyon focus area, is located to the south of Rapid City with one gravity station on the rim of Spring Canyon near the area where Spring Creek sinks into the Madison aquifer. The second area, the Doty focus area, is located on outcrops of the Madison Limestone and Minnelusa Formation to the northwest of Rapid City, and consists of nine gravity stations. The third area, the Limestone Plateau focus area, consists of a single gravity station in the northwestern Black Hills located on an outcrop of the Madison Limestone. An absolute-gravity station, used to tie relative-gravity survey data together, was established on a relatively impermeable

  4. Flow of river water into a karstic limestone aquifer - 2. Dating the young fraction in groundwater mixtures in the Upper Floridan aquifer near Valdosta, Georgia

    USGS Publications Warehouse

    Plummer, L.N.; Busenberg, E.; Drenkard, S.; Schlosser, P.; Ekwurzel, B.; Weppernig, R.; McConnell, J.B.; Michel, R.L.

    1998-01-01

    Tritium/helium-3 (3H/3He) and chlorofluorocarbon (CFCs, CFC-11, CFC-12, CFC-113) data are used to date the young fraction in groundwater mixtures from a karstic limestone aquifer near Valdosta, Georgia, where regional paleowater in the Upper Floridan aquifer receives recharge from two young sources the flow of Withlacoochee River water through sinkholes in the river bed, and leakage of infiltration water through post-Eocene semi-confining beds above the Upper Floridan aquifer. In dating the young fraction of mixtures using CFCs, it is necessary to reconstruct the CFC concentration that was in the young fraction prior to mixing. The 3H/3He age is independent of the extent of dilution with older (3H-free and 3He(trit)-free) water. The groundwater mixtures are designated as Type-I for mixtures of regional paleowater and regional infiltration water and Type-2 for mixtures containing more than approximately 4% of river water. The fractions of regional paleowater, regional infiltration water, and Withlacoochee River water in the groundwater mixtures were determined from Cl- and ??18O data for water from the Upper Floridan aquifer at Valdosta, Georgia The chlorofluorocarbons CFC-11 and CFC-113 are removed by microbial degradation and/or sorption processes in most allaerobic (Type-2) groundwater at Valdosta, but are present in some aerobic Type-I water. CFC-12 persists in both SO4-reducing and methanogenic water. The very low detection limits for CFCs (approximately 0.3 pg kg-1) permitted CFC-11 and CFC-12 dating of the fraction of regional infiltration water in Type-I mixtures, and CFC-12 dating of the river-water fraction in Type-2 mixtures. Overall, approximately 50% of the 85 water sam pies obtained from the Upper Floridan aquifer have CFC-12-based ages of the young traction that are consistent with the 3H concentration of the groundwater. Because of uncertainties associated with very low 3H and 3He content in dilute mixtures, 3H/3He dating is limited to the river

  5. Characterization of aquifer heterogeneity using Cyclostratigraphy and geophysical methods in the upper part of the Karstic Biscayne Aquifer, Southeastern Florida

    USGS Publications Warehouse

    Cunningham, Kevin J.; Carlson, Janine L.; Wingard, G. Lynn; Robinson, Edward; Wacker, Michael A.

    2004-01-01

    This report identifies and characterizes candidate ground-water flow zones in the upper part of the shallow, eogenetic karst limestone of the Biscayne aquifer in the Lake Belt area of north-central Miami-Dade County using cyclostratigraphy, ground-penetrating radar (GPR), borehole geophysical logs, and continuously drilled cores. About 60 miles of GPR profiles were used to calculate depths to shallow geologic contacts and hydrogeologic units, image karst features, and produce qualitative views of the porosity distribution. Descriptions of the lithology, rock fabrics, and cyclostratigraphy, and interpretation of depositional environments of 50 test coreholes were linked to the geophysical interpretations to provide an accurate hydrogeologic framework. Molluscan and benthic foraminiferal paleontologic constraints guided interpretation of depositional environments represented by rockfabric facies. Digital borehole images were used to characterize and quantify large-scale vuggy porosity. Preliminary heat-pulse flowmeter data were coupled with the digital borehole image data to identify candidate ground-water flow zones. Combined results show that the porosity and permeability of the karst limestone of the Biscayne aquifer have a highly heterogeneous and anisotropic distribution that is mostly related to secondary porosity overprinting vertical stacking of rock-fabric facies within high-frequency cycles (HFCs). This distribution of porosity produces a dual-porosity system consisting of diffuse-carbonate and conduit flow zones. The nonuniform ground-water flow in the upper part of the Biscayne aquifer is mostly localized through secondary permeability, the result of solution-enlarged carbonate grains, depositional textures, bedding planes, cracks, root molds, and paleokarst surfaces. Many of the resulting pore types are classified as touching vugs. GPR, borehole geophysical logs, and whole-core analyses show that there is an empirical relation between formation porosity

  6. Abiotic Dissolved Organic Matter-Mineral Interaction in the Karstic Floridan Aquifer

    NASA Astrophysics Data System (ADS)

    Jin, J.; Zimmerman, A.

    2007-12-01

    Dissolved organic matter (DOM)-mineral interaction (e.g. adsorption, desorption, mineral dissolution) in groundwater is a significant factor controlling geochemical, environmental and microbial processes and may be helpful in efforts to track groundwater sources or contaminant fate. Despite its importance, the dynamics and consequences of these abiotic interactions remain poorly understood, largely due to the inaccessibility and heterogeneity of the subsurface, as well as the chemical complexity of DOM. This study models the OM-mineral interactions that takes place in the Floridan aquifer through laboratory adsorption-desorption experiments using DOM (groundwater, river water, soil extracts) and carbonate minerals (calcite, dolomite) collected in north Florida. High performance liquid chromatography-size exclusion chromatography (HPLC-SEC) and UV-fluorescence excitation-emission matrix (EEM) spectrophotometry was used to examine the organic compound types exhibiting preferential affinity for carbonate minerals. Our results show that the DOM-carbonate adsorption/desorption isotherms are well described by the Freundlich model. Freundlich exponents (average value: 0.6488) less than one indicated a filling of adsorption sites. Minerals from Ocala tend to have higher adsorption affinity as well as adsorption capacity than those from Suwannee River Basin; however, both were found to have mineral dissolution. Two fluorescent signals, indicative of a fulvic-like (at excitation wavelength 295-310 nm, emission 400-420 nm) and a protein-like (275/345nm) moiety, were detected in DOM. A reduction in the fulvic-like peak intensity occurred following carbonate adsorption while the protein-like peaks remain almost unchanged indicating the preferential adsorption of fulvic acids. HPLC-SEC results (DOM properties as a function of molecular weight) will be discussed. The chemical properties of DOM in environmental groundwater samples will also be presented and evaluated in light of

  7. Unprotected karst resources in western Iran: the environmental impacts of intensive agricultural pumping on the covered karstic aquifer, a case in Kermanshah province

    NASA Astrophysics Data System (ADS)

    Taheri, Kamal; Taheri, Milad; Parise, Mario

    2015-04-01

    Bare and covered karst areas, with developed karstic aquifers, cover 35 percent of the Kermanshah province in western Iran. These aquifers are the vital sources for drinking and agricultural water supplies. Over the past decade, intensive groundwater use (exploitation) for irrigation imposed a significant impact on the carbonate environments. The huge amount of groundwater over-exploitations has been carried out and still goes on by local farmers in the absence of appropriate governance monitoring control. Increasing in water demands, for more intense crop production, is an important driving force toward groundwater depletion in alluvial aquifers. Progressive groundwater over-exploitations from underlying carbonate rocks have led to dramatic drawdown in alluvial aquifers and deep karst water tables. Detecting new sources of groundwater extractions and prohibiting the karst water utilization for agricultural use could be the most effective strategy to manage the sustainability of covered karst aquifers. Anthropogenic pressures on covered karst aquifers have magnified the drought impacts and caused dryness of most of the karst springs and deep wells. In this study, the combination of geophysical and geological studies was used to estimate the most intensively exploited agricultural zones of Islam Abad plain in the southwestern Kermanshah province using GIS. The results show that in the past decade a great number of deep wells were drilled through the overburden alluvial aquifer and reached the deep karst water resources. However, the difficulties involved in monitoring deep wells in covered karst aquifer were the main cause of karst water depletion. Overexploitation from both alluvial and karst aquifers is the main reason for drying out the Arkawazi, Sharafshah, Gawrawani karst springs, and the karst drinking water wells 1, 3 and 5 of Islam Abad city. Karst spring landscape destructions, fresh water supply deficit for inhabitants, decreasing of tourism and

  8. Simulation of the interaction of karstic lakes Magnolia and Brooklyn with the upper Floridan Aquifer, southwestern Clay County, Florida

    USGS Publications Warehouse

    Merritt, M.L.

    2001-01-01

    The stage of Lake Brooklyn, in southwestern Clay County, Florida, has varied over a range of 27 feet since measurements by the U.S. Geological Survey began in July 1957. The large stage changes have been attributed to the relation between highly transient surface-water inflow to the lake and subsurface conduits of karstic origin that permit a high rate of leakage from the lake to the Upper Floridan aquifer. After the most recent and severe stage decline (1990-1994), the U.S. Geological Survey began a study that entailed the use of numerical ground-water flow models to simulate the interaction of the lake with the Upper Floridan aquifer and the large fluctuations of stage that were a part of that process. A package (set of computer programs) designed to represent lake/aquifer interaction in the U.S. Geological Survey Modular Finite-Difference Ground-Water Flow Model (MODFLOW-96) and the Three-Dimensional Method-of-Characteristics Solute-Transport Model (MOC3D) simulators was prepared as part of this study, and a demonstration of its capability was a primary objective of the study. (Although the official names are Brooklyn Lake and Magnolia Lake (Florida Geographic Names), in this report the local names, Lake Brooklyn and Lake Magnolia, are used.) In the simulator of lake/aquifer interaction used in this investigation, the stage of each lake in a simulation is updated in successive time steps by a budget process that takes into account ground-water seepage, precipitation upon and evaporation from the lake surface, stream inflows and outflows, overland runoff inflows, and augmentation or depletion by artificial means. The simulator was given the capability to simulate both the division of a lake into separate pools as lake stage falls and the coalescence of several pools into a single lake as the stage rises. This representational capability was required to simulate Lake Brooklyn, which can divide into as many as 10 separate pools at sufficiently low stage. In the

  9. Stochastic discrete model of karstic networks

    NASA Astrophysics Data System (ADS)

    Jaquet, O.; Siegel, P.; Klubertanz, G.; Benabderrhamane, H.

    Karst aquifers are characterised by an extreme spatial heterogeneity that strongly influences their hydraulic behaviour and the transport of pollutants. These aquifers are particularly vulnerable to contamination because of their highly permeable networks of conduits. A stochastic model is proposed for the simulation of the geometry of karstic networks at a regional scale. The model integrates the relevant physical processes governing the formation of karstic networks. The discrete simulation of karstic networks is performed with a modified lattice-gas cellular automaton for a representative description of the karstic aquifer geometry. Consequently, more reliable modelling results can be obtained for the management and the protection of karst aquifers. The stochastic model was applied jointly with groundwater modelling techniques to a regional karst aquifer in France for the purpose of resolving surface pollution issues.

  10. Controls of evaporative irrigation return flows in comparison to seawater intrusion in coastal karstic aquifers in northern Sri Lanka: evidence from solutes and stable isotopes

    NASA Astrophysics Data System (ADS)

    Chandrajith, Rohana; Diyabalanage, Saranga; Premathilake, Mahinda; Hanke, Christian; van Geldern, Robert; Barth, Johannes A. C.

    2016-04-01

    Groundwater in Miocene karstic aquifers in the Jaffna Peninsula of Sri Lanka is an important resource since no other fresh water sources are available in the region. The subsurface is characterized by highly productive limestone aquifers that are used for drinking and agriculture purposes. A comprehensive hydrogeochemical study was carried out to reveal the processes affecting the groundwater quality in this region. Major and trace element composition and environmental isotope ratios of oxygen and hydrogen (δ18OH2O and δ2HH2O) were determined in 35 groundwater samples for this investigation. The ion abundance of groundwater in the region was characterized by an anion sequence order with HCO3¯ >Cl¯ >SO4¯ >NO3¯ . For cations, average Na++K+ contents in groundwater exceeded those of Ca2++Mg2+ in most cases. Ionic relationships of major solutes indicated open system calcite dissolution while seawater intrusions are also evident but only close to the coast. The solute contents are enriched by agricultural irrigation returns and associated evaporation. This was confirmed by the stable isotope composition of groundwater that deviated from the local meteoric water line (LMWL) and formed its own regression line denoted as the local evaporation line (LEL). The latter can be described by δ2HH2O=5.8 ×δ18OH2O - 2.9. Increased contents of nitrate (up to 26 mg/L), sulfate (up to 430 mg/L) and fluoride (up to 1.5 mg/L) provided evidences for anthropogenic inputs of solutes, most likely from agriculture activities. Among trace elements Ba, Sr, As and Se levels in the Jaffna groundwater were higher compared to that of the dry zone metamorphic aquifers in Sri Lanka. Solute geochemistry and stable isotope evidences from the region indicates that groundwater in the area is mainly derived from local modern precipitation but modified heavily by progressive evaporative concentration rather than seawater intrusion. The currently most imminent vulnerability of groundwater in the

  11. Insights into saline intrusion and freshwater resources in coastal karstic aquifers using a lumped Rainfall-Discharge-Salinity model (the Port-Miou brackish spring, SE France)

    NASA Astrophysics Data System (ADS)

    Arfib, Bruno; Charlier, Jean-Baptiste

    2016-09-01

    The aim of this study was to develop a conceptual model of saline intrusion within coastal karst aquifers by analyzing Rainfall-Discharge-Salinity data and to assess freshwater resources using a lumped modeling approach. In a first step, we analyzed 4 years of data (rainfall, discharge and salinity times series) of the Port-Miou brackish submarine spring in South France (400 km2). A conceptual model of the aquifer was then designed to differentiate a deep brackish reservoir and a shallower fresh one. Salinity variations at the spring are assumed to be controlled mainly by dilution originating from the fresh water in the shallower reservoir. In a second step, a lumped modeling approach was developed based on the conceptual model to simulate discharge as well as salinity over time. We proposed a reservoir-model to take into account slow and fast components in the shallower part of the aquifer and a saline intrusion in the deeper one. This Rainfall-Discharge-Salinity model was calibrated and validated for two periods of 1.5 years at a daily time step and was also tested to reproduce a multi-annual evolution of the available discharge and salinity time series. Good simulation results were obtained to reproduce water and mass budgets as well as discharge and salinity dynamics during several hydrological cycles. The simultaneous modeling of hydrodynamics and quality data showed the robustness of the model in addition to its easy implementation. Our results led us to propose a new type of seawater mixing mechanism for brackish springs: the dilution type, in addition to the well-known Ventury suction and Head balance types. The application of the lumped model on the Port-Miou brackish spring validated the hydrogeological processes deduced from experimental data, given an initial quantification of the freshwater resources available in such complex brackish karstic aquifers.

  12. Controls of evaporative irrigation return flows in comparison to seawater intrusion in coastal karstic aquifers in northern Sri Lanka: Evidence from solutes and stable isotopes.

    PubMed

    Chandrajith, Rohana; Diyabalanage, Saranga; Premathilake, K M; Hanke, Christian; van Geldern, Robert; Barth, Johannes A C

    2016-04-01

    Groundwater in Miocene karstic aquifers in the Jaffna Peninsula of Sri Lanka is an important resource since no other fresh water sources are available in the region. The subsurface is characterized by highly productive limestone aquifers that are used for drinking and agriculture purposes. A comprehensive hydrogeochemical study was carried out to reveal the processes affecting the groundwater quality in this region. Major and trace element composition and environmental isotope ratios of oxygen and hydrogen (δ(18)OH2O and δ(2)HH2O) were determined in 35 groundwater samples for this investigation. The ion abundance of groundwater in the region was characterized by an anion sequence order with HCO3->Cl->SO4->NO3-. For cations, average Na(+)+K(+) contents in groundwater exceeded those of Ca(2+)+Mg(2+) in most cases. Ionic relationships of major solutes indicated open system calcite dissolution while seawater intrusions are also evident but only close to the coast. The solute contents are enriched by agricultural irrigation returns and associated evaporation. This was confirmed by the stable isotope composition of groundwater that deviated from the local meteoric water line (LMWL) and formed its own regression line denoted as the local evaporation line (LEL). The latter can be described by δ(2)HH2O=5.8×δ(18)OH2O -- 2.9. Increased contents of nitrate-N (up to 5mg/L), sulfate (up to 430mg/L) and fluoride (up to 1.5mg/L) provided evidences for anthropogenic inputs of solutes, most likely from agriculture activities. Among trace elements Ba, Sr, As and Se levels in the Jaffna groundwater were higher compared to that of the dry zone metamorphic aquifers in Sri Lanka. Solute geochemistry and stable isotope evidences from the region indicates that groundwater in the area is mainly derived from local modern precipitation but modified heavily by progressive evaporative concentration rather than seawater intrusion. PMID:26803741

  13. Groundwater flow modeling of two-levels perched karstic leaking aquifers as a tool for estimating recharge and hydraulic parameters

    NASA Astrophysics Data System (ADS)

    Peleg, Nadav; Gvirtzman, Haim

    2010-06-01

    SummaryPerched springs in nature emerge from aquifers laying on aquitards within the unsaturated zone, some of which emerge one above the other. A finite element model was introduced, using the FEFLOW code, for simulating the groundwater flow regime in each of these aquifers, for quantifying the fraction of rain that recharges the aquifers, and for estimating the hydrogeological parameters of the aquifers and aquitards. Many of the perched springs in Israel are found in the Judea Group aquifer, a stratified carbonate rock unit, characterised by a well-developed karst system. The Batir and Jamia springs exemplifies such a system, where Batir is the upper spring discharging at the contact between Aminadav and Moza Formations, and Jamia is the lower one, discharging at the contact between Kesalon and Sorek Formations. The 25-year-long measured spring's hydrographs were used to calibrate the spring's coefficients, the hydraulic conductivities of the different layers, the karst features and the yearly amount of rain recharging the spring.

  14. New method for quantification of vuggy porosity from digital optical borehole images as applied to the karstic Pleistocene limestone of the Biscayne aquifer, southeastern Florida

    USGS Publications Warehouse

    Cunningham, K.J.; Carlson, J.I.; Hurley, N.F.

    2004-01-01

    Vuggy porosity is gas- or fluid-filled openings in rock matrix that are large enough to be seen with the unaided eye. Well-connected vugs can form major conduits for flow of ground water, especially in carbonate rocks. This paper presents a new method for quantification of vuggy porosity calculated from digital borehole images collected from 47 test coreholes that penetrate the karstic Pleistocene limestone of the Biscayne aquifer, southeastern Florida. Basically, the method interprets vugs and background based on the grayscale color of each in digital borehole images and calculates a percentage of vuggy porosity. Development of the method was complicated because environmental conditions created an uneven grayscale contrast in the borehole images that makes it difficult to distinguish vugs from background. The irregular contrast was produced by unbalanced illumination of the borehole wall, which was a result of eccentering of the borehole-image logging tool. Experimentation showed that a simple, single grayscale threshold would not realistically differentiate between the grayscale contrast of vugs and background. Therefore, an equation was developed for an effective subtraction of the changing grayscale contrast, due to uneven illumination, to produce a grayscale threshold that successfully identifies vugs. In the equation, a moving average calculated around the circumference of the borehole and expressed as the background grayscale intensity is defined as a baseline from which to identify a grayscale threshold for vugs. A constant was derived empirically by calibration with vuggy porosity values derived from digital images of slabbed-core samples and used to make the subtraction from the background baseline to derive the vug grayscale threshold as a function of azimuth. The method should be effective in estimating vuggy porosity in any carbonate aquifer. ?? 2003 Published by Elsevier B.V.

  15. Flow of river water into a Karstic limestone aquifer. 1. Tracing the young fraction in groundwater mixtures in the Upper Floridan Aquifer near Valdosta, Georgia

    USGS Publications Warehouse

    Plummer, L.N.; Busenberg, E.; McConnell, J.B.; Drenkard, S.; Schlosser, P.; Michel, R.L.

    1998-01-01

    The quality of water ill the Upper Floridan aquifer near Valdosta, Georgia is affected locally by discharge of Withlacoochee River water through sinkholes in the river bed. Data on transient tracers and other dissolved substances, including Cl-, 3H, tritiogenic helium-3 (3He), chlorofluorocarbons (CFC-11, CFC-12, CFC-113), organic C (DOC), O2 (DO), H2S, CH4, ??18O, ??D, and 14C were investigated as tracers of Withlacoochee River water in the Upper Floridan aquifer. The concentrations of all tracers were affected by dilution and mixing. Dissolved Cl-, ??18O, ??D, CFC-12, and the quantity (3H + 3He) are stable in water from the Upper Floridan aquifer, whereas DOC, DO, H2S, CH4, 14C, CFC- 11, and CFC-113 are affected by microbial degradation and other geochemical processes occurring within the aquifer. Groundwater mixing fractions were determined by using dissolved Cl- and ??18O data, recognizing 3 end-member water types in the groundwater mixtures: (1) Withlacoochee River water (??18O = -2.5 ?? 0.3???, Cl-= 12.2 ?? 2 mg/l), (2) regional infiltration water (??18O = -4.2 ?? 0.1???o Cl-=2.3??0.1 mg/l), and (3) regional paleowater resident in the Upper Floridan aquifer (??18O = - 3.4 ?? 0.1???, Cl- = 2.6 ?? 0.1 mg/l) (uncertainties are + l??). Error simulation procedures were used to define uncertainties in mixing fractions. Fractions of river water in groundwater range from 0 to 72% and average 10%. The influence of river-water discharge on the quality of water in the Upper Floridan aquifer was traced from the sinkhole area on the Withlacoochee River 25 km SE in the direction of regional groundwater flow. Infiltration of water is most significant to the N and NW of Valdosta, but becomes negligible to the S and SE in the direction of general thickening of post-Eocene confining beds overlying the Upper Floridan aquifer.

  16. Bitter Melon

    MedlinePlus

    African Cucumber, Ampalaya, Balsam Pear, Balsam-Apple, Balsambirne, Balsamo, Bitter Apple, Bitter Cucumber, Bitter Gourd, Bittergurke, Carilla Fruit, Carilla Gourd, Cerasee, Chinli-Chih, Cundeamor, Fructus Mormordicae Grosvenori, Karavella, Kathilla, ...

  17. Using stable isotopes and multi-spatial variable parameters in characterising the karstic aquifer of the Ajloun area, NW-Jordan - A case study of the Tanour and Rasoun springs

    NASA Astrophysics Data System (ADS)

    Hamdan, Ibraheem; Wiegand, Bettina; Ptak, Thomas; Licha, Tobias; Toll, Mathias; Margane, Armin; Sauter, Martin

    2015-04-01

    Key words: Karst systems, Groundwater vulnerability, Stable isotopes, Jordan. Water resources are extremely scarce in Jordan, which is considered as one of the poorest countries in the world with respect to water resources availability (UNDP 2014), with more than 90% of the country receiving less than 200 mm/year of rainfall (Al Kharadsheh et al. 2012). The most important aquifer for drinking-water purposes in Jordan is the upper Cretaceous limestone aquifer. The karstic springs of Tanour and Rasoun, located in the Ajloun governorate around 75 kilometres northwest of the capital of Amman, have been selected for this study. These springs are the main source for the local domestic water supply, with an average discharge between the years 2000 and 2012 of 200 m3/h and 60 m3/h, respectively (MWI, 2013). During the past few years, the water supply from these two springs had to be discontinued due to high contamination of the groundwater either by microbiological contaminants or by wastewater from local olive oil presses. This wastewater is locally called 'Zeebar'. Understanding of the karst aquifer system, the pathways and movement within the epikarst, and estimation of the travel and residence time within the aquifer is important for managing and evaluating the pollution risk, which affects the usability of groundwater for drinking purposes. For a better understanding of the karstic system and its behaviour, different methods are applied: 1. Analysis of the stable isotope composition of δ2H and δ18O during the winter season for both (a) Tanour and Rasoun groundwater, and (b) rainfall samples collected from several locations at different elevations within the catchment. 2. Analysis of major ion concentrations in groundwater of the Tanour and Rasoun springs. 3. Long-term measurements of different physico-chemical parameters from the Tanour and Rasoun springs (temperature, conductivity, turbidity, TOC, etc.) using multiparameter probes with telemetric data transfer. 4

  18. Geochemical And Hydrodynamic Behavior Of The Karstic Aquifer System In The Portion Between Akumal And Boca Paila, In The South Eastern Coast Of The Yucatan Peninsula.

    NASA Astrophysics Data System (ADS)

    Velazquez Oliman, G.; Leal Bautista, R. M.; Perry, E. C.; Carrol, M.; Wagner, N.; Castillo Oliman, P.

    2008-12-01

    We report here aspects of the geochemistry and hydrodynamics of a nearly 450 km2 area that constitutes part of the rapidly developing tourist corridor between Akumal and Boca Paila, Quintana Roo, Mexico. Some of the largest explored submerged cave systems in the world, including Nohoch Nah Chic and Dos Ojos, are within the study area. The presence of these and other highly permeable conduits highlights the importance of a better understanding of the aquifer system both to assess its vulnerability and to facilitate sustainable water management. This study focuses on major ion, trace element, and stable isotope geochemistry of groundwater and on monitoring system hydrodynamics through water levels measurements. Sampling along approximately 30 km of coast was accomplished by means of a network of 29 sampling sites arranged along three NW-SE transverse lines running approximately perpendicular to the coast and each extending about 16 km inland. To date 52 samples have been taken. In addition, vertical specific conductivity profiles have helped delineate the thickness of the freshwater lens, which has a maximum thickness of 33.5 m in the southwestern part of the study area, approximately 13.5 km from the coast. In the northeastern corner of the study area, 7.5 m of brackish water overlies sea water near the coast. Water level monitoring is by means of Schlumberger pressure transducers installed at 11 sites. Water table changes record tidal oscillation, confirming the interconnectedness of the system, an observation supported by conductivity measurements that indicate oscillatory vertical movement of the saline interface. (SO4/Cl) ratios, expressed as 1000(SO4/Cl) in meq/kg, are useful tracers of groundwater provenance. The ratio is approximately 100 for seawater and is much greater for groundwater in southern Quintana Roo that has dissolved evaporite (Perry et al, 2002). Ratios in the study area, which are 100 or less, indicate no contact with evaporite. Background

  19. Étude du fonctionnement du système aquifére karstique Cénomano-Turonien de l'oued Igrounzar, bassin d'Essaouira, MarocStudy of the karstic Cenomanian-Turonian aquifer along Wadi Igrounzar, Essaouira Basin, Morocco

    NASA Astrophysics Data System (ADS)

    Jalal, M.; Blavoux, B.; Bahir, M.; Bellion, Y.; Laftouhi, N. E.; Puig, J. M.; Mennani, A.; Daniel, M.

    2001-05-01

    In the Meskala-Kourimat area, the Bouabout Syncline aquifer system, intersected by the Igrounzar Wadi, feeds most of the karstic sources of the region. This aquifer is contained within Cenomanian and Turonian limestones and dolomitic limestones. The base of the system corresponds to the lower Cenomanian grey clays, and the top to the Senonian white marls. Hydrodynamic studies of various springs shows that each water source is different from the other, indicating a heterogeneous underground reservoir belonging to a complex karst system. The springs waters show a large chemical variability in space and time. These waters are a mixture of chloride, sulphate, Na and Mg. High Mg contents of some springs result from dissolution of evaporite, confirmed by low Ca/Mg ratios. The total dissolved solids (TDS) in spring water increases from upstream to downstream, probably as a response to residency time, but also due to interaction with Cenomanian evaporites. However, the springs are good for drinking water, as well as for irrigation. The monthly survey of selected springs indicated a large chemical variability but with little or no correlation between discharge and TDS. Stable isotope data ( 18O) suggests that the altitude of the recharge area, for this aquifer system, is ˜ 1200 m. The 18O gradient versus altitude, established on springs whose recharge areas are well known is, -0.25% versus SMOW/100 m. When compared with the 'Meteoric Water Line' established on worldwide spring water whose recharge areas are well known, the Essaouira Basin shows rain recharge without any significant evaporation.

  20. Karstic Phenomena Susceptibility Map of MÉXICO

    NASA Astrophysics Data System (ADS)

    Espinasa-Pereña, R.

    2013-05-01

    Approximately 20% of the territory of México is underlain by karstifiable rocks, mostly limestones and in lesser proportions gypsum. The majority of these rocks are distributed along the eastern and southern Sierra Madre, the state of Chiapas and the Yucatán peninsula. Differences in geological structure, climate and geomorphic history have resulted in a great variety of karstic landscapes and types of forms. Several important population centers, including large cities with several million inhabitants and numerous smaller towns are built on karstic terrains and obtain their water supplies from karstic aquifers and/or dispose of their waste products on this type of terrain. Severe problems of waste disposal and aquifer contamination have occurred. Additionally, numerous instances of catastrophic collapse and formation of karstic sinkholes have been registered in the Mexican territory, which have affected many communities, roads and other infrastructure, and have even cost several lives. Lack of knowledge of the special characteristics of karstic terrains and their distribution has compounded these problems. As a first approach to these issues, the existing map of Mexican karst (Espinasa-Pereña, 2007) was modified according to the geotechnical classification proposed by Waltham & Fookes (2003). An important consideration taken into account is the difference in speed of development of karstic features depending on lithology, which makes karst developed in gypsum much more hazardous than limestone karst, and also the degree of soil coverage and the types of sinkholes developed on the cover. Also taken in consideration are the differences between karst developed in the Sierra Madre, with rocks highly deformed and fractured, and karst developed on the Yucatán peninsula with almost negligible deformation of the rocks. The resulting map will be useful to Civil Protection authorities as a tool in prognosticating possible affectations due to karstic phenomena. References

  1. Hydrogeological and hydrogeochemical characterization of a karstic mountain region

    NASA Astrophysics Data System (ADS)

    Simsek, Celalettin; Elci, Alper; Gunduz, Orhan; Erdogan, Burhan

    2008-03-01

    Karstic limestone formations in the Mediterranean basin are potential water resources that can meet a significant portion of groundwater demand. Therefore, it is necessary to thoroughly study the hydrogeology and hydrogeochemistry of karstic mountain regions. This paper presents a detailed hydrogeological and hydrogeochemical characterization of the Nif Mountain karstic aquifer system in western Turkey, an important recharge source for the densely populated surrounding area. Based on the geological and hydrogeological studies, four major aquifers were identified in the study area including the allochthonous limestone in Bornova flysch, conglomerate-sandstone and clayey-limestone in Neogene series, and the Quaternary alluvium. Physicochemical characteristics of groundwater were measured in situ, and samples were collected at 59 locations comprised of springs and wells. Samples were analyzed for major ions, isotopic composition, arsenic, boron and heavy metals among other trace elements. It was found that the hydrogeological structure is complex with many springs having a wide range of discharge rates. High-discharge springs originate from allochthonous limestone units, whereas low-discharge springs are formed at the contacts with claystone and limestone units. Using stable isotope analysis data, a δ18O-deuterium relationship was obtained that lies between the Mediterranean meteoric and mean global lines. Tritium analyses showed that low-discharge springs originating from contact zones had longer circulation times compared to the high-discharge karstic springs. Furthermore, hydrogeochemical data revealed that groundwater quality significantly deteriorated as water moved from the mountain to the plains. Heavy metal, arsenic and boron concentrations were generally within drinking-water quality standards with a few exceptions occurring in residential and industrial areas located at the foothills of the mountain. Elevated arsenic concentrations were related to local

  2. Damage caused by long-term, gradual karstic subsidence

    SciTech Connect

    Beck, B.F.; Jenkins, D.T.; Parker, J.W.

    1985-01-01

    Damage due to karstic subsidence (sinkhole collapse) is generally presumed to be relatively rapid in human terms. However, during repaving of a runway apron at Mac Dill Air Force Base, Tampa, Florida, 41 shallow depressions were formed during proof rolling. The apron is underlain by 6-10 m of sand and clayey sand over the limestones of the Floridan Aquifer, which are known for their karst. The apron was originally paved in 1952. Ground penetrating radar revealed that a radar-reflecting boundary, circa 4-5 m below the surface, had also subsided in an inverted-conical pattern beneath the depressions, as well as in other areas. Beneath some of the areas the pavement subbase had also subsided similarly. VLF surveys over and around the depressions mapped a linear trend identical to the apparent alignment of the depressions. Close-spaced drilling confirmed that the subsidence was directly over a depression in the limestone surface. Further, the overlying sand had an N = 0-1, whereas the surrounding sand tested N = 4-6. The authors have concluded that gradual erosion of the overlying sand into karstic depressions and voids in the limestone over a 32 year period has reduced the sand density and strength and caused subsidence where the overlying pavement was loaded.

  3. BitterDB: a database of bitter compounds

    PubMed Central

    Wiener, Ayana; Shudler, Marina; Levit, Anat; Niv, Masha Y.

    2012-01-01

    Basic taste qualities like sour, salty, sweet, bitter and umami serve specific functions in identifying food components found in the diet of humans and animals, and are recognized by proteins in the oral cavity. Recognition of bitter taste and aversion to it are thought to protect the organism against the ingestion of poisonous food compounds, which are often bitter. Interestingly, bitter taste receptors are expressed not only in the mouth but also in extraoral tissues, such as the gastrointestinal tract, indicating that they may play a role in digestive and metabolic processes. BitterDB database, available at http://bitterdb.agri.huji.ac.il/bitterdb/, includes over 550 compounds that were reported to taste bitter to humans. The compounds can be searched by name, chemical structure, similarity to other bitter compounds, association with a particular human bitter taste receptor, and so on. The database also contains information on mutations in bitter taste receptors that were shown to influence receptor activation by bitter compounds. The aim of BitterDB is to facilitate studying the chemical features associated with bitterness. These studies may contribute to predicting bitterness of unknown compounds, predicting ligands for bitter receptors from different species and rational design of bitterness modulators. PMID:21940398

  4. Drosophila Bitter Taste(s).

    PubMed

    French, Alice; Ali Agha, Moutaz; Mitra, Aniruddha; Yanagawa, Aya; Sellier, Marie-Jeanne; Marion-Poll, Frédéric

    2015-01-01

    Most animals possess taste receptors neurons detecting potentially noxious compounds. In humans, the ligands which activate these neurons define a sensory space called "bitter". By extension, this term has been used in animals and insects to define molecules which induce aversive responses. In this review, based on our observations carried out in Drosophila, we examine how bitter compounds are detected and if bitter-sensitive neurons respond only to molecules bitter to humans. Like most animals, flies detect bitter chemicals through a specific population of taste neurons, distinct from those responding to sugars or to other modalities. Activating bitter-sensitive taste neurons induces aversive reactions and inhibits feeding. Bitter molecules also contribute to the suppression of sugar-neuron responses and can lead to a complete inhibition of the responses to sugar at the periphery. Since some bitter molecules activate bitter-sensitive neurons and some inhibit sugar detection, bitter molecules are represented by two sensory spaces which are only partially congruent. In addition to molecules which impact feeding, we recently discovered that the activation of bitter-sensitive neurons also induces grooming. Bitter-sensitive neurons of the wings and of the legs can sense chemicals from the gram negative bacteria, Escherichia coli, thus adding another biological function to these receptors. Bitter-sensitive neurons of the proboscis also respond to the inhibitory pheromone, 7-tricosene. Activating these neurons by bitter molecules in the context of sexual encounter inhibits courting and sexual reproduction, while activating these neurons with 7-tricosene in a feeding context will inhibit feeding. The picture that emerges from these observations is that the taste system is composed of detectors which monitor different "categories" of ligands, which facilitate or inhibit behaviors depending on the context (feeding, sexual reproduction, hygienic behavior), thus considerably

  5. Suppression of bitterness by sodium: variation among bitter taste stimuli.

    PubMed

    Breslin, P A; Beauchamp, G K

    1995-12-01

    Taste interactions between salts (NaCl, LiCl, KCl, L-arginine:L-aspartic acid, Na-acetate and Na-gluconate) and bitter-tasting compounds (urea, quinine HCl, magnesium sulphate, KCl, amiloride HCl and caffeine) were investigated. In each study binary combinations of three or four concentrations of one bitter compound with four concentrations (0, 0.1, 0.3 and 0.5 M) of one salt were rated for bitterness and saltiness using the method of magnitude estimation. In most cases, perceived bitterness was suppressed by salts, although the degree of suppression varied. In general, bitterness suppression was not accompanied by an equivalent reciprocal suppression of saltiness. Only MgSO4 and amiloride had suppressing effects on the saltiness of NaCl at the intermediate concentrations and no bitter compound affected the saltiness at the high concentrations of NaCl. Since salt suppressed the bitterness of urea effectively, a detailed analysis of suppression of the bitterness of urea by different salts was conducted. Those studies indicated that the key component in this effect was the sodium or lithium ion for two reasons: first, all three sodium salts and the lithium salt had a suppressive effect on bitterness, whereas KCl did not; secondly, the effect of a salt on suppression of the bitterness of urea was independent of its perceived saltiness; that is, NaCl, Na-acetate (which is perceived as less salty than NaCl), and Na-gluconate (which is perceived as less salty than Na-acetate) reduced bitterness comparably. These results suggest that there is a major peripheral component to the suppression of the bitterness of urea, and perhaps other bitter tasting compounds, by sodium. PMID:8788095

  6. Drosophila Bitter Taste(s)

    PubMed Central

    French, Alice; Ali Agha, Moutaz; Mitra, Aniruddha; Yanagawa, Aya; Sellier, Marie-Jeanne; Marion-Poll, Frédéric

    2015-01-01

    Most animals possess taste receptors neurons detecting potentially noxious compounds. In humans, the ligands which activate these neurons define a sensory space called “bitter”. By extension, this term has been used in animals and insects to define molecules which induce aversive responses. In this review, based on our observations carried out in Drosophila, we examine how bitter compounds are detected and if bitter-sensitive neurons respond only to molecules bitter to humans. Like most animals, flies detect bitter chemicals through a specific population of taste neurons, distinct from those responding to sugars or to other modalities. Activating bitter-sensitive taste neurons induces aversive reactions and inhibits feeding. Bitter molecules also contribute to the suppression of sugar-neuron responses and can lead to a complete inhibition of the responses to sugar at the periphery. Since some bitter molecules activate bitter-sensitive neurons and some inhibit sugar detection, bitter molecules are represented by two sensory spaces which are only partially congruent. In addition to molecules which impact feeding, we recently discovered that the activation of bitter-sensitive neurons also induces grooming. Bitter-sensitive neurons of the wings and of the legs can sense chemicals from the gram negative bacteria, Escherichia coli, thus adding another biological function to these receptors. Bitter-sensitive neurons of the proboscis also respond to the inhibitory pheromone, 7-tricosene. Activating these neurons by bitter molecules in the context of sexual encounter inhibits courting and sexual reproduction, while activating these neurons with 7-tricosene in a feeding context will inhibit feeding. The picture that emerges from these observations is that the taste system is composed of detectors which monitor different “categories” of ligands, which facilitate or inhibit behaviors depending on the context (feeding, sexual reproduction, hygienic behavior), thus

  7. Transfer function approach for artificial tracer test interpretation in karstic systems

    NASA Astrophysics Data System (ADS)

    Labat, D.; Mangin, A.

    2015-10-01

    A karstic formation consists in a three-dimensional hydrological system which involves horizontal and vertical, diphasic or saturated water transfers characterised by a large range of velocity. These subsurface flow processes correspond to various water pathways through fractured, fissured, and underground streams or conduits leading to a nonlinear global behaviour of the system. An efficient way of investigating of a karstic system behaviour consists in the injection of artificial tracer tests at loss points and in careful analysis of the recovery tracer fluxes at one or several outlets of the systems. These injections are also an efficient way of providing hypotheses on characteristic time of contaminant transfer in these type of aquifers. Here, we propose a Laplace-transform transfer function of the Residence Time Distribution function that allows to discriminate between a quick-flow advection-dominated component and a slow-flow advection-dispersion/dominated component in the artificial tracer transfer in the system. We apply this transfer function on five high resolution sampling rate artificial tracer tests operated on the Baget system in the Pyrenees (France) in order to illustrate the advantages and limitations of this approach. We provide then an interpretation of the relationship between tracer test recovery shape and karstic system organisation between inlet and outlet site.

  8. Karstic water storage response to the recent droughts in Southwest China estimated from satellite gravimetry

    NASA Astrophysics Data System (ADS)

    Yao, Chaolong; Luo, Zhicai

    2015-12-01

    The water resources crisis is intensifying in Southwest China (SWC), which includes the world's largest continuous coverage of karst landforms, due to recent severe drought events. However, because of the special properties of karstic water system, such as strong heterogeneity, monitoring the variation of karstic water resources at large scales remains still difficult. Satellite gravimetry has emerged as an effective tool for investigating the global and regional water cycles. In this study, we used GRACE (Gravity Recovery and Climate Experiment) data from January 2003 to January 2013 to investigate karstic water storage variability over the karst region of SWC. We assessed the impacts of the recent severe droughts on karst water resources, including two heavy droughts in September 2010 to May 2010 and August 2011 to January 2012. Results show a slightly water increase tend during the studied period, but these two severe droughts have resulted in significant water depletion in the studied karst region. The latter drought during 2011 and 2012 caused more water deficits than that of the drought in 2010. Strong correlation between the variations of GRACE-based total water storage and precipitation suggests that climate change is the main driving force for the significant water absent over the studied karst region. As the world's largest continuous coverage karst aquifer, the karst region of SWC offers an example of GRACE applications to a karst system incisively and will benefit for water management from a long-term perspective in karst systems throughout the world.

  9. Geologic framework and hydrogeologic characteristics of the Edwards aquifer outcrop (Barton Springs segment), northeastern Hays and southwestern Travis Counties, Texas

    USGS Publications Warehouse

    Small, Ted A.; Hanson, John A.; Hauwert, Nico M.

    1996-01-01

    In the Barton Springs segment of the Edwards aquifer, the aquifer probably is most vulnerable to surface contamination in the rapidly urbanizing areas on the Edwards aquifer outcrop. Contamination can result from spills or leakage of hazardous materials; or runoff on the intensely faulted and fractured, karstic limestone outcrops characteristic of the recharge zone.

  10. Bitter Gourd: Botany, Horticulture, Breeding

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bitter gourd fruits are a good source of carbohydrates, proteins, vitamins, and minerals and have the highest nutritive value among cucurbits. Moreover, the crude protein content (11.4-20.9 g.kg-1) of bitter gourd fruits is higher than that of tomato and cucumber. This book chapter focuses on the ...

  11. Catchment scale tracer testing from karstic features in a porous limestone

    NASA Astrophysics Data System (ADS)

    Maurice, L.; Atkinson, T. C.; Williams, A. T.; Barker, J. A.; Farrant, A. R.

    2010-07-01

    SummaryTracer testing was undertaken from sinking streams feeding the Chalk, a porous limestone aquifer characterised by frequent small-scale surface karst features. The objective was to investigate the nature and extent of sub-surface karstic development in the aquifer. Previous tracer testing has demonstrated rapid flow combined with low attenuation of tracer. In this study, at two sites rapid groundwater flow was combined with very high attenuation and at two other sites no tracer was detected at springs within the likely catchment area of the stream sinks tested, suggesting that tracer was totally attenuated along the flowpath. It is proposed that the networks beneath stream sinks in the Chalk and other mildly karstic aquifers distribute recharge into multiple enlarged fractures that divide and become smaller at each division whereas the networks around springs have a predominantly tributary topology that concentrates flow into a few relatively large cavities, a morphology with similarities to that of the early stages of karstification. Tracer attenuation is controlled by the degree to which the two networks are directly connected. In the first state, there is no direct linkage and flow between the two networks is via primary fractures in which tracer attenuation is extreme. The second state is at a percolation threshold in which a single direct link joins the two networks. A very small proportion of tracer reaches the spring rapidly but overall attenuation is very high. In the third state, the recharge and discharge networks are integrated therefore a large fraction of tracer reaches the spring and peak concentrations are relatively high. Despite the large number of stream sinks that recharge the Chalk aquifer, these results suggest that sub-surface conduit development may not always be continuous, with flow down smaller fissures and fractures causing high attenuation of solutes and particulates providing a degree of protection to groundwater outlets that is

  12. A revision of the "African Non-Spiny" Clade of Solanum L. (Solanum sections Afrosolanum Bitter, Benderianum Bitter, Lemurisolanum Bitter, Lyciosolanum Bitter, Macronesiotes Bitter, and Quadrangulare Bitter: Solanaceae).

    PubMed

    Knapp, Sandra; Vorontsova, Maria S

    2016-01-01

    The African Non-Spiny (ANS) clade contains 14 species of mostly large canopy lianas or scandent shrubs confined to Madagascar (10) and continental Africa (4, with with one species reaching the southern Arabian peninsula). Members of the clade were previously classified in sections Afrosolanum Bitter, Benderianum Bitter, Lemurisolanum Bitter, Macronesiotes Bitter and Quadrangulare Bitter, and were throught to be related to a variety of New World groups. The group is an early-branching lineage of non-spiny solanums and characters shared with other vining New World solanums are homoplastic. The 14 species of the group occupy a wide range of habitats, from wet forests in western Africa to savanna and dry forests of southern Madagascar and dune habitats in South Africa. Many members of the group are highly variable morphologically, and habit can vary between shrub and canopy vine in a single locality. We here review the taxonomic history, morphology, potential relationships and ecology of these species; we provide keys for their identification, descriptions, full synonymy (including designations of lectotypes and neotypes) and nomenclatural notes. Illustrations, distribution maps and preliminary conservation assessments are provided for all species. PMID:27489494

  13. BitterX: a tool for understanding bitter taste in humans.

    PubMed

    Huang, Wenkang; Shen, Qiancheng; Su, Xubo; Ji, Mingfei; Liu, Xinyi; Chen, Yingyi; Lu, Shaoyong; Zhuang, Hanyi; Zhang, Jian

    2016-04-04

    BitterX is an open-access tool aimed at providing a platform for identifying human bitter taste receptors, TAS2Rs, for small molecules. It predicts TAS2Rs from the molecular structures of arbitrary chemicals by integrating two individual functionalities: bitterant verification and TAS2R recognition. Using BitterX, several novel bitterants and their receptors were predicted and experimentally validated in the study. Therefore, BitterX may be an effective method for deciphering bitter taste coding and could be a useful tool for both basic bitter research in academia and new bitterant discoveries in the industry.

  14. Geologic framework and hydrogeologic characteristics of the Edwards Aquifer outcrop, Comal County, Texas

    USGS Publications Warehouse

    Small, T.A.; Hanson, J.A.

    1994-01-01

    In Comal County, the Edwards aquifer is probably most vulnerable to surface contamination in the rapidly urbanizing areas on the Edwards aquifer outcrop. Possible contamination can result from spills, leakage of hazardous materials, or runoff onto the intensely faulted and fractured, karstic limestone outcrops characteristic of the recharge zone.

  15. Bitter melon: antagonist to cancer.

    PubMed

    Nerurkar, Pratibha; Ray, Ratna B

    2010-06-01

    The incidence of cancer is increasing worldwide, in spite of substantial progress in the development of anti-cancer therapies. One approach to control cancer could be its prevention by diet, which inhibits one or more neoplastic events and reduces cancer risk. Dietary compounds offer great potential in the fight against cancer by inhibiting the carcinogenesis process through the regulation of cell homeostasis and cell-death machineries. For centuries, Ayurveda (Indian traditional medicine) has recommended the use of bitter melon (Momordica charantia) as a functional food to prevent and treat diabetes and associated complications. It is noteworthy to mention that bitter melon extract has no-to-low side effects in animals as well as in humans. The anti-tumor activity of bitter melon has recently begun to emerge. This review focuses on recent advancements in cancer chemopreventive and anti-cancer efficacy of bitter melon and its active constituents. Several groups of investigators have reported that treatment of bitter-melon-related products in a number of cancer cell lines induces cell cycle arrest and apoptosis without affecting normal cell growth. Therefore, the effect of bitter melon should be beneficial for health, and use of the non-modified dietary product is cost effective. PMID:20198408

  16. Management of karstic coastal groundwater in a changing environment (Salento, southern Italy)

    NASA Astrophysics Data System (ADS)

    Polemio, Maurizio; Romanazzi, Andrea

    2014-05-01

    groundwater trends from 1930 to 2060 and emphasizes an essential decrease of piezometric level and a huge worsening of the groundwater salinisation due seawater intrusion. More details on previous results of this research activity were recently published (Polemio and Romanazzi, 2012; Romanazzi and Polemio, 2013). References Polemio M., Romanazzi A., (2013), A groundwater model to support the management water resources of coastal karstic aquifer of salento (south italy), Rend. Online Soc. Geol. It., Atti del IX Convegno Nazionale dei Giovani Ricercatori di Geologia Applicata, Vol. 24 (2013), pp. 254-256. Romanazzi A., Polemio M., (2013), Modelling of coastal karst aquifers for management support: Study of Salento (Apulia, Italy), Italian Journal of Engineering Geology and Environment, 13, 1, pp. 65-83.

  17. Is the bitter rejection response always adaptive?

    PubMed

    Glendinning, J I

    1994-12-01

    The bitter rejection response consists of a suite of withdrawal reflexes and negative affective responses. It is generally assumed to have evolved as a way to facilitate avoidance of foods that are poisonous because they usually taste bitter to humans. Using previously published studies, the present paper examines the relationship between bitterness and toxicity in mammals, and then assesses the ecological costs and benefits of the bitter rejection response in carnivorous, omnivorous, and herbivorous (grazing and browsing) mammals. If the bitter rejection response accurately predicts the potential toxicity of foods, then one would expect the threshold for the response to be lower for highly toxic compounds than for nontoxic compounds. The data revealed no such relationship. Bitter taste thresholds varied independently of toxicity thresholds, indicating that the bitter rejection response is just as likely to be elicited by a harmless bitter food as it is by a harmful one. Thus, it is not necessarily in an animal's best interest to have an extremely high or low bitter threshold. Based on this observation, it was hypothesized that the adaptiveness of the bitter rejection response depends upon the relative occurrence of bitter and potentially toxic compounds in an animal's diet. Animals with a relatively high occurrence of bitter and potentially toxic compounds in their diet (e.g., browsing herbivores) were predicted to have evolved a high bitter taste threshold and tolerance to dietary poisons. Such an adaptation would be necessary because a browser cannot "afford" to reject all foods that are bitter and potentially toxic without unduly restricting its dietary options. At the other extreme, animals that rarely encounter bitter and potentially toxic compounds in their diet (e.g., carnivores) were predicted to have evolved a low bitter threshold. Carnivores could "afford" to utilize such a stringent rejection mechanism because foods containing bitter and potentially

  18. Is the bitter rejection response always adaptive?

    PubMed

    Glendinning, J I

    1994-12-01

    The bitter rejection response consists of a suite of withdrawal reflexes and negative affective responses. It is generally assumed to have evolved as a way to facilitate avoidance of foods that are poisonous because they usually taste bitter to humans. Using previously published studies, the present paper examines the relationship between bitterness and toxicity in mammals, and then assesses the ecological costs and benefits of the bitter rejection response in carnivorous, omnivorous, and herbivorous (grazing and browsing) mammals. If the bitter rejection response accurately predicts the potential toxicity of foods, then one would expect the threshold for the response to be lower for highly toxic compounds than for nontoxic compounds. The data revealed no such relationship. Bitter taste thresholds varied independently of toxicity thresholds, indicating that the bitter rejection response is just as likely to be elicited by a harmless bitter food as it is by a harmful one. Thus, it is not necessarily in an animal's best interest to have an extremely high or low bitter threshold. Based on this observation, it was hypothesized that the adaptiveness of the bitter rejection response depends upon the relative occurrence of bitter and potentially toxic compounds in an animal's diet. Animals with a relatively high occurrence of bitter and potentially toxic compounds in their diet (e.g., browsing herbivores) were predicted to have evolved a high bitter taste threshold and tolerance to dietary poisons. Such an adaptation would be necessary because a browser cannot "afford" to reject all foods that are bitter and potentially toxic without unduly restricting its dietary options. At the other extreme, animals that rarely encounter bitter and potentially toxic compounds in their diet (e.g., carnivores) were predicted to have evolved a low bitter threshold. Carnivores could "afford" to utilize such a stringent rejection mechanism because foods containing bitter and potentially

  19. Mixing of shallow and deep groundwater as indicated by the chemistry and age of karstic springs

    USGS Publications Warehouse

    Toth, D.J.; Katz, B.G.

    2006-01-01

    Large karstic springs in east-central Florida, USA were studied using multi-tracer and geochemical modeling techniques to better understand groundwater flow paths and mixing of shallow and deep groundwater. Spring water types included Ca-HCO3 (six), Na-Cl (four), and mixed (one). The evolution of water chemistry for Ca-HCO3 spring waters was modeled by reactions of rainwater with soil organic matter, calcite, and dolomite under oxic conditions. The Na-Cl and mixed-type springs were modeled by reactions of either rainwater or Upper Floridan aquifer water with soil organic matter, calcite, and dolomite under oxic conditions and mixed with varying proportions of saline Lower Floridan aquifer water, which represented 4-53% of the total spring discharge. Multiple-tracer data-chlorofluorocarbon CFC-113, tritium (3H), helium-3 (3Hetrit), sulfur hexafluoride (SF6) - for four Ca-HCO3 spring waters were consistent with binary mixing curves representing water recharged during 1980 or 1990 mixing with an older (recharged before 1940) tracer-free component. Young-water mixing fractions ranged from 0.3 to 0.7. Tracer concentration data for two Na-Cl spring waters appear to be consistent with binary mixtures of 1990 water with older water recharged in 1965 or 1975. Nitrate-N concentrations are inversely related to apparent ages of spring waters, which indicated that elevated nitrate-N concentrations were likely contributed from recent recharge. ?? Springer-Verlag 2006.

  20. Occurrence of multi-antibiotic resistant Pseudomonas spp. in drinking water produced from karstic hydrosystems.

    PubMed

    Flores Ribeiro, Angela; Bodilis, Josselin; Alonso, Lise; Buquet, Sylvaine; Feuilloley, Marc; Dupont, Jean-Paul; Pawlak, Barbara

    2014-08-15

    Aquatic environments could play a role in the spread of antibiotic resistance genes by enabling antibiotic-resistant bacteria transferred through wastewater inputs to connect with autochthonous bacteria. Consequently, drinking water could be a potential pathway to humans and animals for antibiotic resistance genes. The aim of this study was to investigate occurrences of Escherichia coli and Pseudomonas spp. in drinking water produced from a karst, a vulnerable aquifer with frequent increases in water turbidity after rainfall events and run-offs. Water samples were collected throughout the system from the karstic springs to the drinking water tap during three non-turbid periods and two turbid events. E. coli densities in the springs were 10- to 1000-fold higher during the turbid events than during the non-turbid periods, indicating that, with increased turbidity, surface water had entered the karstic system and contaminated the spring water. However, no E. coli were isolated in the drinking water. In contrast, Pseudomonas spp. were isolated from the drinking water only during turbid events, while the densities in the springs were from 10- to 100-fold higher than in the non-turbid periods. All the 580 Pseudomonas spp. isolates obtained from the sampling periods were resistant (to between 1 and 10 antibiotics), with similar resistance patterns. Among all the Pseudomonas isolated throughout the drinking water production system, between 32% and 86% carried the major resistance pattern: ticarcillin, ticarcillin-clavulanic acid, cefsulodin, and/or aztreonam, and/or sulfamethoxazol-trimethoprim, and/or fosfomycin. Finally, 8 Pseudomonas spp. isolates, related to the Pseudomonas putida and Pseudomonas fluorescens species, were isolated from the drinking water. Thus, Pseudomonas could be involved in the dissemination of antibiotic resistance via drinking water during critical periods.

  1. Bitter Root Irrigation district canal, looking east, typical section (canal ...

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

    Bitter Root Irrigation district canal, looking east, typical section (canal full) - Bitter Root Irrigation Project, Bitter Root Irrigation Canal, Heading at Rock Creek Diversion Dam, West of U.S. Highway 93, Darby, Ravalli County, MT

  2. Bitter Root Irrigation district canal, looking east, typical section and ...

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

    Bitter Root Irrigation district canal, looking east, typical section and crossing - Bitter Root Irrigation Project, Bitter Root Irrigation Canal, Heading at Rock Creek Diversion Dam, West of U.S. Highway 93, Darby, Ravalli County, MT

  3. Neural responses to bitter compounds in rats.

    PubMed

    Dahl, M; Erickson, R P; Simon, S A

    1997-05-01

    To determine whether the idiosyncratic distribution of transduction mechanisms for bitter tastants in rat taste receptor cells (TRCs) could be inferred from the neural activity they evoke, single neuron responses to ten bitter-tasting compounds were recorded from rat glossopharyngeal (n = 30) and chorda tympani (n = 22) neurons. Responses to several 'bitter' alkaloids were obtained: 10 mM quinine-HCl, 50 mM caffeine, and 1 mM each nicotine, yohimbine, and strychnine, plus a number of non-alkaloid bitter-tasting compounds: 0.1 M KCl, 0.01 M MgCl2, and 1 mM each phenylthiocarbamide (PTC), L-tyrosine, and denatonium benzoate. To obtain some distinctions with other stimuli NaCl (0.1 M), HCl (pH 2.0), and capsaicin (10 microM) were also tested. It was found that individual neurons in both glossopharyngeal and chorda tympani nerves differed in their relative sensitivities to the various bitter stimuli. To determine relationships among these stimuli, the differences in the evoked responses between each stimulus pair were summarized in a multi-dimensional scaling space. In these analyses neither nerve showed any obvious similarity between the placements of quinine and the other bitter stimuli. Such data suggest that first-order gustatory neurons can discriminate among the above bitter stimuli. For glossopharyngeal neurons, some similarity to quinine was found only for nicotine and denatonium, and for chorda tympani neurons, some similarity to quinine was found only for KCl and MgCl2. Of the bitter compounds tested, quinine evoked the greatest response from glossopharyngeal neurons. We propose this arises because quinine can activate TRCs by more transduction mechanisms than other bitter stimuli. The results from these studies were summarized in a qualitative model for the coding of bitter tastants where the variety of transduction mechanisms for bitters are distributed among various TRCs to account for the heterogeneous responses among the neurons.

  4. Preliminary Map of Potentially Karstic Carbonate Rocks in the Central and Southern Appalachian States

    USGS Publications Warehouse

    Weary, David J.

    2008-01-01

    Karst is a landscape produced by dissolution of rocks and the development of integrated subterranean drainages dominated by the flow of ground water in solutionally enlarged conduits. Karst landscapes typically include cave entrances, sinkholes, blind valleys, losing streams, springs, and large and small-scale solution features on bedrock surfaces. Water-bearing rocks beneath the surface containing solutionally enlarged pores, fractures, or conduits are referred to as karst aquifers. About 40 percent of all ground water extracted in the United States comes from karst aquifers (Karst Waters Institute). Karst means many things to many people. To most cavers and many speleologists, karst means areas containing caves. To engineers, home builders, local governments, and insurance companies, karst is exemplified by the occurrence of sinkholes and subsidence hazard. To hydrologists, well drillers, and environmental consultants, the focus on karst may be more limited to karst aquifers and springs. Precise figures are not available, but ground collapses in karst areas in the United States require hundreds of millions of dollars in repair and mitigation costs each year. Most karst in the United States is formed in either carbonate or evaporite rocks. This map depicts only areas of carbonate rock outcrop, the chief host for karst formation in the eastern United States. The U.S. Geological Survey (USGS), in cooperation with the National Cave and Karst Research Institute (NCKRI), the National Speleological Society (NSS), and various State geological surveys, is working on a new national karst map that will delineate areas of karst and karst-like features nationwide. This product attempts to identify potentially karstic areas of the Appalachian states as defined by the Appalachian Regional Commission (ARC), with the addition of the state of Delaware. This map is labeled preliminary because there is an expectation that it will be revised and updated as part of a new national

  5. The impact of hop bitter acid and polyphenol profiles on the perceived bitterness of beer.

    PubMed

    Oladokun, Olayide; Tarrega, Amparo; James, Sue; Smart, Katherine; Hort, Joanne; Cook, David

    2016-08-15

    Thirty-four commercial lager beers were analysed for their hop bitter acid, phenolic acid and polyphenol contents. Based on analytical data, it was evident that the beers had been produced using a range of different raw materials and hopping practices. Principal Components Analysis was used to select a sub-set of 10 beers that contained diverse concentrations of the analysed bitter compounds. These beers were appraised sensorially to determine the impacts of varying hop acid and polyphenolic profiles on perceived bitterness character. Beers high in polyphenol and hop acid contents were perceived as having 'harsh' and 'progressive' bitterness, whilst beers that had evidently been conventionally hopped were 'sharp' and 'instant' in their bitterness. Beers containing light-stable hop products (tetrahydro-iso-α-acids) were perceived as 'diminishing', 'rounded' and 'acidic' in bitterness. The hopping strategy adopted by brewers impacts on the nature, temporal profile and intensity of bitterness perception in beer.

  6. The impact of hop bitter acid and polyphenol profiles on the perceived bitterness of beer.

    PubMed

    Oladokun, Olayide; Tarrega, Amparo; James, Sue; Smart, Katherine; Hort, Joanne; Cook, David

    2016-08-15

    Thirty-four commercial lager beers were analysed for their hop bitter acid, phenolic acid and polyphenol contents. Based on analytical data, it was evident that the beers had been produced using a range of different raw materials and hopping practices. Principal Components Analysis was used to select a sub-set of 10 beers that contained diverse concentrations of the analysed bitter compounds. These beers were appraised sensorially to determine the impacts of varying hop acid and polyphenolic profiles on perceived bitterness character. Beers high in polyphenol and hop acid contents were perceived as having 'harsh' and 'progressive' bitterness, whilst beers that had evidently been conventionally hopped were 'sharp' and 'instant' in their bitterness. Beers containing light-stable hop products (tetrahydro-iso-α-acids) were perceived as 'diminishing', 'rounded' and 'acidic' in bitterness. The hopping strategy adopted by brewers impacts on the nature, temporal profile and intensity of bitterness perception in beer. PMID:27006233

  7. Cycloheximide: No Ordinary Bitter Stimulus

    PubMed Central

    Hettinger, Thomas P.; Formaker, Bradley K.; Frank, Marion E.

    2007-01-01

    Cycloheximide (CyX), a toxic antibiotic with a unique chemical structure generated by the actinomycete, Streptomyces griseus, has emerged as a primary focus of studies on mammalian bitter taste. Rats and mice avoid it at concentrations well below the thresholds for most bitter stimuli and T2R G-protein-coupled receptors specific for CyX with appropriate sensitivity are identified for those species. Like mouse and rat, golden hamsters, Mesocricetus auratus, also detected and rejected micromolar levels of CyX, although 1 mM CyX failed to activate the hamster chorda tympani nerve. Hamsters showed an initial tolerance for 500 μM CyX, but after that, avoidance of CyX dramatically increased, plasticity not reported for rat or mouse. As the hamster lineage branches well before division of the mouse-rat lineage in evolutionary time, differences between hamster and mouse-rat reactions to CyX are not surprising. Furthermore, unlike hamster LiCl-induced learned aversions, the induced CyX aversion neither specifically nor robustly generalized to other non-ionic bitter stimuli; and unlike adverse reactions to other chemosensory stimuli, aversions to CyX were not mollified by adding a sweetener. Thus, CyX is unlike other bitter stimuli. The gene for the high-affinity CyX receptor is a member of a cluster of 5 orthologous T2R genes that are likely rodent specific; this “CyX clade” is found in the mouse, rat and probably hamster, but not in the human or rabbit genome. The rodent CyX-T2R interaction may be one of multiple lineage-specific stimulus-receptor interactions reflecting a response to a particular environmental toxin. The combination of T2R multiplicity, species divergence and gene duplication results in diverse ligands for multiple species-specific T2R receptors, which confounds definition of ‘bitter’ stimuli across species. PMID:17400304

  8. Hydrogeological and isotope mapping of the karstic Savica River (NW Slovenia)

    NASA Astrophysics Data System (ADS)

    Brenčič, Mihael; Vreča, Polona

    2015-04-01

    karstic aquifer draining through Savica springs and direct inflows of groundwater into the riverbed.

  9. Taste perception of bitter compounds in young and elderly persons: relation to lipophilicity of bitter compounds.

    PubMed

    Schiffman, S S; Gatlin, L A; Frey, A E; Heiman, S A; Stagner, W C; Cooper, D C

    1994-01-01

    Threshold and suprathreshold sensitivities to 13 bitter compounds were determined for 16 young adults (mean age = 27.4 years) and 18 elderly persons (mean age = 81.3 years). Half of the subjects in each age group were tasters of the bitter compound phenylthiocarbamide (PTC) and half were nontasters. Both detection and recognition thresholds, determined by a forced-choice ascending detection method, were elevated in older subjects; there were no significant differences in threshold values between tasters and nontasters of PTC. A strong relationship between bitter threshold values and the logarithm of the octanol/water partition coefficient was found for both young and elderly subjects. For young subjects, suprathreshold bitterness ratings were more intense for tasters of PTC compared with nontasters. Significant losses in suprathreshold sensitivity to bitter tastants with age were also found. However, unlike threshold sensitivity, no relationship was found between suprathreshold bitter taste intensity and lipophilicity.

  10. Effects of sweet, bitter and soaked micronised bitter lupins on duckling performance.

    PubMed

    Olver, M D; Jonker, A

    1998-12-01

    1. The feeding value of sweet white lupins (Lupinus albus variety Hanli), bitter lupins (Lupinus angustifolius) and soaked micronised bitter lupins on male Pekin duckling performance was examined. 2. Four isocaloric and isonitrogenous diets were formulated with 1 containing no lupin and the other 3 containing 400 g/kg sweet, bitter or soaked micronised bitter lupins. The 3 lupin diets were then blended appropriately to produce 16 experimental diets containing 0, 50, 100, 200, 300 and 400 g/kg sweet, bitter and soaked micronised bitter lupins, and fed to Cherry Valley Super M Pekin ducklings for 6 weeks. 3. The feeding of bitter lupins to ducklings at 200, 300 and 400 g/kg diet resulted in a poorer performance (P < 0.01) with regard to body weight gain, food intake and food conversion ratio than feeding the control diet. Carcase moisture was higher and carcase fat content lower (P < 0.01) at the 400 g/kg concentration only. No significant differences were observed with carcase protein or carcase ash content. No significant differences were observed between treatments and the control when different amounts of sweet or soaked micronised bitter lupins were fed. 4. There were significant linear adverse responses (P < 0.01) with bitter lupins in most of the variables studied whereas no responses were observed with sweet or soaked micronised bitter lupins as the concentration of lupins in the diet increased. The soaked micronised bitter lupins performed as well as the sweet lupins, showing that the amount of bitter lupins used in duckling diets can be increased to 400 g/kg after this treatment.

  11. Bitter taste markers explain variability in vegetable sweetness, bitterness, and intake.

    PubMed

    Dinehart, M E; Hayes, J E; Bartoshuk, L M; Lanier, S L; Duffy, V B

    2006-02-28

    Intake of vegetables falls short of recommendations to lower risk of chronic diseases. Most research addresses bitterness as a sensory deterrent to consuming vegetables. We examined bitter and sweet sensations from vegetables as mediators of vegetable preference and intake as well as how these tastes vary with markers of genetic variation in taste (3.2 mM 6-n-propylthiouracil bitterness) and taste pathology (1.0 mM quinine bitterness, chorda tympani nerve relative to whole mouth). Seventy-one females and 39 males (18-60 years) reported prototypical tastes from and preference for Brussels sprouts, kale and asparagus as well as servings of vegetables consumed, excluding salad and potatoes. Intensity and hedonic ratings were made with the general Labeled Magnitude Scale. Data were analyzed with multiple linear regression and structural equation modeling. Vegetable sweetness and bitterness were independent predictors of more or less preference for sampled vegetables and vegetable intake, respectively. Those who taste PROP as most bitter also tasted the vegetables as most bitter and least sweet. The spatial pattern of quinine bitterness, suggestive of insult to chorda tympani taste fibers, was associated with less bitterness and sweetness from vegetables. Via structural equation modeling, PROP best explained variability in vegetable preference and intake via vegetable bitterness whereas the quinine marker explained variability in vegetable preference and intake via vegetable bitterness and sweetness. In summary, bitterness and sweetness of sampled vegetables varied by taste genetic and taste function markers, which explained differences in preference for vegetables tasted in the laboratory as well as overall vegetable intake outside the laboratory.

  12. A revision of the “African Non-Spiny” Clade of Solanum L. (Solanum sections Afrosolanum Bitter, Benderianum Bitter, Lemurisolanum Bitter, Lyciosolanum Bitter, Macronesiotes Bitter, and Quadrangulare Bitter: Solanaceae)

    PubMed Central

    Knapp, Sandra; Vorontsova, Maria S.

    2016-01-01

    Abstract The African Non-Spiny (ANS) clade contains 14 species of mostly large canopy lianas or scandent shrubs confined to Madagascar (10) and continental Africa (4, with with one species reaching the southern Arabian peninsula). Members of the clade were previously classified in sections Afrosolanum Bitter, Benderianum Bitter, Lemurisolanum Bitter, Macronesiotes Bitter and Quadrangulare Bitter, and were throught to be related to a variety of New World groups. The group is an early-branching lineage of non-spiny solanums and characters shared with other vining New World solanums are homoplastic. The 14 species of the group occupy a wide range of habitats, from wet forests in western Africa to savanna and dry forests of southern Madagascar and dune habitats in South Africa. Many members of the group are highly variable morphologically, and habit can vary between shrub and canopy vine in a single locality. We here review the taxonomic history, morphology, potential relationships and ecology of these species; we provide keys for their identification, descriptions, full synonymy (including designations of lectotypes and neotypes) and nomenclatural notes. Illustrations, distribution maps and preliminary conservation assessments are provided for all species. PMID:27489494

  13. Bitterness in Almonds1[C][OA

    PubMed Central

    Sánchez-Pérez, Raquel; Jørgensen, Kirsten; Olsen, Carl Erik; Dicenta, Federico; Møller, Birger Lindberg

    2008-01-01

    Bitterness in almond (Prunus dulcis) is determined by the content of the cyanogenic diglucoside amygdalin. The ability to synthesize and degrade prunasin and amygdalin in the almond kernel was studied throughout the growth season using four different genotypes for bitterness. Liquid chromatography-mass spectrometry analyses showed a specific developmentally dependent accumulation of prunasin in the tegument of the bitter genotype. The prunasin level decreased concomitant with the initiation of amygdalin accumulation in the cotyledons of the bitter genotype. By administration of radiolabeled phenylalanine, the tegument was identified as a specific site of synthesis of prunasin in all four genotypes. A major difference between sweet and bitter genotypes was observed upon staining of thin sections of teguments and cotyledons for β-glucosidase activity using Fast Blue BB salt. In the sweet genotype, the inner epidermis in the tegument facing the nucellus was rich in cytoplasmic and vacuolar localized β-glucosidase activity, whereas in the bitter cultivar, the β-glucosidase activity in this cell layer was low. These combined data show that in the bitter genotype, prunasin synthesized in the tegument is transported into the cotyledon via the transfer cells and converted into amygdalin in the developing almond seed, whereas in the sweet genotype, amygdalin formation is prevented because the prunasin is degraded upon passage of the β-glucosidase-rich cell layer in the inner epidermis of the tegument. The prunasin turnover may offer a buffer supply of ammonia, aspartic acid, and asparagine enabling the plants to balance the supply of nitrogen to the developing cotyledons. PMID:18192442

  14. Paleokarstic and karstic features: Arbuckle and Hunton Groups, Oklahoma

    SciTech Connect

    Al-Shaieb, Z.; Puckette, J.; Matthews, F. . School of Geology); Lynch, M. )

    1993-02-01

    Cores of the Ordovician-age Arbuckle Group and Ordovician-Silurian-Devonian-age Hunton Group contain evidence of paleokarst. Arbuckle and Hunton Group rocks display surprisingly similar suites of distinct paleo-karstic features. Vugs, solution-enlarged fractures, cavities, collapse breccias, and sediment-filled solution features are evident. Phreatic cements are more commonly observed than vadose cements, while primary speleothemic precipitates are rare. A complex history of exposure, subsidence, and diagenesis is recorded in these rocks. Hunton and Arbuckle carbonates have been subaerially exposed for periods of variable intensity and duration during geologic history. Paleokarst appears to have developed subjacent to disconformities within and between formations of the Arbuckle Group and where these rocks subcrop below regional unconformities. Hunton paleokarstic horizons are apparent below the regional pre-Woodford unconformity, while evidence of inter- and intra-formational subaerial exposure is tenuous. This complex hierarchy of unconformities can produce numerous porous horizons. Porosity preservation may depend on subsidence rates or sea level rises rapid enough to prevent extensive low-temperature phreatic cementation and sediment infill of the existing pore network. Caves in the Arbuckle Group in Murray County, Oklahoma contain many karstic features similar to those observed in cores. Cemented collapse breccia and sediment-filled solution cavities are evident in caves developed in the Cool Creek Formation. These caves are part of an extensive internal drainage system associated with Honey Creek near the crest of the Arbuckle anticline. Cave speleothems and surficial travertine deposits are by-product of karstification processes.

  15. Are large karstic springs good indicators for Climate Change effects on groundwater?

    NASA Astrophysics Data System (ADS)

    Preziosi, Elisabetta; Romano, Emanuele

    2013-04-01

    Climate changes are expected to decrease the water availability in the Mediterranean area especially during summer, due to the concurrence of a generalized negative trend in the precipitation and an increased frequency of droughts. The use of groundwater can mitigate droughts, because many aquifers have a large storage capacity and are potentially less sensitive to climate change than surface water bodies, which often rely on groundwater discharge to maintain their baseflow. However, the real effects of precipitation decline on water availability must also account for human impacts, which conversely tend to increase, partly as a result of climate change. Especially, the so called secondary impacts of climate change, resulting from human intervention in water systems, are expected to have the largest short-term effects on groundwater resources. Typical examples of secondary impacts on groundwater are the increased abstractions particularly for irrigation. For these reasons, groundwater heads are hardly directly usable as indicators of climate change effects. On the other hand, large springs in mountain aquifers, which are very little or not affected by well pumping, could be helpful to evaluate the primary impacts of climate changes on groundwaters, although the paucity of long-term historical data often limits an effective assessment of the direct consequences of climatic forcing. In this research we analyse three different unconfined karstic aquifers in Central Italy, with average discharge ranging from 120 L/s to nearly 18 m3/s, which exhibit consistent signals of the direct effects of climate changes on groundwater resources. The analysed time series, although discontinuous, indicate declines of about 20% of the initial discharge rate (10 years average) in the period 1938-2007. The detected trends are also coherent with that of the regional standardized precipitation index and the Tiber river discharge. Additionally, they show a fair correlation with the

  16. Antibiotic-resistant Escherichia coli in karstic systems: a biological indicator of the origin of fecal contamination?

    PubMed

    Ribeiro, Angela Flores; Laroche, Emilie; Hanin, Guillaume; Fournier, Matthieu; Quillet, Laurent; Dupont, Jean-Paul; Pawlak, Barbara

    2012-07-01

    Occurrences of antibiotic-resistant Escherichia coli in two springs of a karstic system (NW France) providing drinking water were determined to study the role of aquifers in the dissemination of the resistance genes. Water samples were collected during wet and dry periods and after a heavy rainfall event to investigate E. coli density, antibiotic resistance patterns, and occurrences of class 1, 2, and 3 integrons. By observing patterns of the resistant isolates (i.e. number and type of resistances) and their occurrences, we were able to define two resistant subpopulations, introduced in the aquifer via surface water: (1) R1-2, characterized by one or two resistance(s), essentially to chloramphenicol and/or tetracycline (96.5%), was always found during the heavy rainfall event; (2) R3-10, characterized by three or more resistances, mostly resistant to tetracycline (94.1%) and beta-lactams (86%), was found transiently. Class 1 and 2 integrons were detected, mostly in the R3-10 subpopulation for class 1 integrons. The characteristics of these two subpopulations strongly suggest that the contamination originates from pasture runoff for the R1-2 subpopulation and from wastewater treatment plant effluents for the R3-10 subpopulation. These two subpopulations of E. coli could be used as biological indicators to determine the origin of groundwater contamination.

  17. Contribution of groundwater discharge to the coastal dissolved nutrients and trace metal concentrations in Majorca Island: karstic vs detrital systems.

    PubMed

    Tovar-Sánchez, Antonio; Basterretxea, Gotzon; Rodellas, Valentí; Sánchez-Quiles, David; García-Orellana, Jordi; Masqué, Pere; Jordi, Antoni; López, José M; Garcia-Solsona, Ester

    2014-10-21

    Submarine groundwater discharge (SGD) and derived nutrient (NO2(-), NO3(-), NH4(+), PO4(3-), and SiO2) and trace element (Cd, Co, Cu, Fe, Mo, Ni, Pb, V and Zn) loadings to the coastal sea were systematically assessed along the coast of Majorca Island, Spain, in a general survey around the island and in three representative coves during 2010. We estimated that brackish water discharges through the shoreline are important contributors to the DIN, SiO2, Fe, and Zn budgets of the nearshore waters. Furthermore, our results showed that SGD-derived elements are conditioned by the hydrogeological formations of the aquifer and discharge type. Thus, while rapid discharges through karstic conduits are enriched in SiO2 and Zn, the large detrital aquifers of the island typically present enhanced concentrations of Fe. The estimated total annual inputs of chemicals constituents discharged by SGD to the coastal waters were as follows: DIN: 610 × 10(3) kg yr(-1), SiO2: 1400 × 10(3) kg yr(-1), Fe: 3.2 × 10(3) kg yr(-1), and Zn: 2.0 × 10(3) kg yr(-1). Our results provide evidence that SGD is a major contributor to the dissolved pool of inorganic nutrients and trace metals in the nearshore waters of Majorca.

  18. Contribution of groundwater discharge to the coastal dissolved nutrients and trace metal concentrations in Majorca Island: karstic vs detrital systems.

    PubMed

    Tovar-Sánchez, Antonio; Basterretxea, Gotzon; Rodellas, Valentí; Sánchez-Quiles, David; García-Orellana, Jordi; Masqué, Pere; Jordi, Antoni; López, José M; Garcia-Solsona, Ester

    2014-10-21

    Submarine groundwater discharge (SGD) and derived nutrient (NO2(-), NO3(-), NH4(+), PO4(3-), and SiO2) and trace element (Cd, Co, Cu, Fe, Mo, Ni, Pb, V and Zn) loadings to the coastal sea were systematically assessed along the coast of Majorca Island, Spain, in a general survey around the island and in three representative coves during 2010. We estimated that brackish water discharges through the shoreline are important contributors to the DIN, SiO2, Fe, and Zn budgets of the nearshore waters. Furthermore, our results showed that SGD-derived elements are conditioned by the hydrogeological formations of the aquifer and discharge type. Thus, while rapid discharges through karstic conduits are enriched in SiO2 and Zn, the large detrital aquifers of the island typically present enhanced concentrations of Fe. The estimated total annual inputs of chemicals constituents discharged by SGD to the coastal waters were as follows: DIN: 610 × 10(3) kg yr(-1), SiO2: 1400 × 10(3) kg yr(-1), Fe: 3.2 × 10(3) kg yr(-1), and Zn: 2.0 × 10(3) kg yr(-1). Our results provide evidence that SGD is a major contributor to the dissolved pool of inorganic nutrients and trace metals in the nearshore waters of Majorca. PMID:25215451

  19. Future Availability of Water Supply from Karstic Springs under Probable Climate Change. The case of Aravissos, Central Macedonia, Greece.

    NASA Astrophysics Data System (ADS)

    Vafeiadis, M.; Spachos, Th.; Zampetoglou, K.; Soupilas, Th.

    2012-04-01

    The test site of Aravissos is located at 70 Km to the West (W-NW) of Thessaloniki at the south banks of mount Païko, in the north part of Central Macedonia The karstic Aravissos springs supply 40% of total volume needed for the water supply of Thessaloniki, Greece. As the water is of excellent quality, it is feed directly in the distribution network without any previous treatment. The availability of this source is therefore of high importance for the sustainable water supply of this area with almost 1000000 inhabitants. The water system of Aravissos is developed in a karstic limestone with an age of about Late Cretaceous that covers almost the entire western part of the big-anticline of Païko Mountain. The climate in this area and the water consumption area, Thessaloniki, is a typical Mediterranean climate with mild and humid winters and hot and dry summers. The total annual number of rainy days is around 110. The production of the Aravissos springs depends mostly from the annual precipitations. As the feeding catchement and the karst aquifer are not well defined, a practical empirical balance model, that contains only well known relevant terms, is applied for the simulation of the operation of the springs under normal water extraction for water supply in present time. The estimation of future weather conditions are based on GCM and RCM simulation data and the extension of trend lines of the actual data. The future evolution of the availability of adequate water quantities from the springs is finally estimated from the balance model and the simulated future climatic data. This study has been realised within the project CC-WaterS, funded by the SEE program of the European Regional Development Fund (http://www.ccwaters.eu/).

  20. Vegetable Bitterness is Related to Calcium Content

    PubMed Central

    Tordoff, Michael G.; Sandell, Mari A.

    2009-01-01

    In the U.S. and Europe, most people do not consume the recommended amounts of either calcium or vegetables. We investigated whether there might be a connection; specifically, whether the taste of calcium in vegetables contributes to their bitterness and thus acceptability. We found a strong correlation between the calcium content of 24 vegetables, based on USDA Nutrient Database values, and bitterness, based on the average ratings of 35 people (r = 0.93). Correlations between the content of other nutrients and bitterness were lower and most were not statistically significant. To assess whether it is feasible that humans can detect calcium in vegetables we tested two animal models known to display a calcium appetite. Previous work indicates that calcium solutions are preferentially ingested by PWK/PhJ mice relative to C57BL/6J mice, and by rats deprived of dietary calcium relative to replete controls. In choice tests between collard greens, a high-calcium vegetable, and cabbage, a low-calcium vegetable, the calcium-favoring animals had higher preferences for collard greens than did controls. These observations raise the possibility that the taste of calcium contributes to the bitterness and thus acceptability of vegetables. PMID:19260165

  1. Bitter taste receptors: Extraoral roles in pathophysiology.

    PubMed

    Shaik, Feroz Ahmed; Singh, Nisha; Arakawa, Makoto; Duan, Kangmin; Bhullar, Rajinder P; Chelikani, Prashen

    2016-08-01

    Over the past decade tremendous progress has been made in understanding the functional role of bitter taste receptors (T2Rs) and bitter taste perception. This review will cover the recent advances made in identifying the role of T2Rs in pathophysiological states. T2Rs are widely expressed in various parts of human anatomy and have been shown to be involved in physiology of respiratory system, gastrointestinal tract and endocrine system. Empirical evidence has shown T2Rs to be an integral component of antimicrobial immune responses in upper respiratory tract infections. The studies on human airway smooth muscle cells have shown that a potent bitter tastant induced bronchodilatory effects mediated by bitter taste receptors. Clinical data suggests a role for T2R38 polymorphism in predisposition of individuals to chronic rhinosinusitis. The role of genetic variation in T2Rs and its impact on disease susceptibility have been investigated in various other disease risk factors such as alcohol dependence, head and neck cancers. Preliminary reports have demonstrated differential expression of functional T2Rs in breast cancer cell lines. Studies on the role of T2Rs in pathophysiology of diseases including chronic rhinosinusitis, asthma, cystic fibrosis, and cancer have been promising. However, research in this field is in its nascent stages, and more confirmatory studies on animal models and in clinical settings are required. PMID:27032752

  2. Carbonate aquifers

    USGS Publications Warehouse

    Cunningham, Kevin J.; Sukop, Michael; Curran, H. Allen

    2012-01-01

    Only limited hydrogeological research has been conducted using ichnology in carbonate aquifer characterization. Regardless, important applications of ichnology to carbonate aquifer characterization include its use to distinguish and delineate depositional cycles, correlate mappable biogenically altered surfaces, identify zones of preferential groundwater flow and paleogroundwater flow, and better understand the origin of ichnofabric-related karst features. Three case studies, which include Pleistocene carbonate rocks of the Biscayne aquifer in southern Florida and Cretaceous carbonate strata of the Edwards–Trinity aquifer system in central Texas, demonstrate that (1) there can be a strong relation between ichnofabrics and groundwater flow in carbonate aquifers and (2) ichnology can offer a useful methodology for carbonate aquifer characterization. In these examples, zones of extremely permeable, ichnofabric-related macroporosity are mappable stratiform geobodies and as such can be represented in groundwater flow and transport simulations.

  3. Bitter taste receptors confer diverse functions to neurons

    PubMed Central

    Delventhal, Rebecca; Carlson, John R

    2016-01-01

    Bitter compounds elicit an aversive response. In Drosophila, bitter-sensitive taste neurons coexpress many members of the Gr family of taste receptors. However, the molecular logic of bitter signaling is unknown. We used an in vivo expression approach to analyze the logic of bitter taste signaling. Ectopic or overexpression of bitter Grs increased endogenous responses or conferred novel responses. Surprisingly, expression of Grs also suppressed many endogenous bitter responses. Conversely, deletion of an endogenous Gr led to novel responses. Expression of individual Grs conferred strikingly different effects in different neurons. The results support a model in which bitter Grs interact, exhibiting competition, inhibition, or activation. The results have broad implications for the problem of how taste systems evolve to detect new environmental dangers. DOI: http://dx.doi.org/10.7554/eLife.11181.001 PMID:26880560

  4. Karstic slope "breathing": morpho-structural influence and hazard implications

    NASA Astrophysics Data System (ADS)

    Devoti, Roberto; Falcucci, Emanuela; Gori, Stefano; Eliana Poli, Maria; Zanferrari, Adriano; Braitenberg, Carla; Fabris, Paolo; Grillo, Barbara; Zuliani, David

    2016-04-01

    The study refers to the active slope deformation detected by GPS and tiltmeter stations in the Cansiglio karstic plateau located in the western Carnic Prealps (NE Italy). The observed transient deformation clearly correlates with the rainfall, so that the southernmost border of the Plateau reacts instantly to heavy rains displaying a "back and forth" deformation up to a few centimeters wide, with different time constants, demonstrating a response to different catchment volumes. We carried out a field survey along the southern Cansiglio slope, to achieve structural characterization of the relief and to verify the possible relation between structural features and the peculiar geomorphological setting dominated by widespread karstic features. The Cansiglio plateau develops on the frontal ramp anticline of the Cansiglio thrust, an about ENE-WSW trending, SSE-verging, low angle thrust, belonging to the Neogene-Quaternary front of the eastern Southern Alps. The Cansiglio thrust outcrops at the base of the Cansiglio plateau, where it overlaps the Mesozoic carbonates on the Miocene-Quaternary terrigenous succession. All along its length cataclastic limestone largely outcrop. The Cansiglio thrust is bordered by two transfer zones probably inherited from the Mesozoic paleogeography: the Caneva fault in the west and the Col Longone fault in the east. The carbonatic massif is also characterized by a series of about northward steeply dipping reverse minor faults and a set of subvertical joints parallel to the axes of the Cansiglio anticline. Other NNW-SSE and NNE-SSW conjugate faults and fractures perpendicular to the Cansiglio southern slope are also identified. This structural setting affect pervasively the whole slope and may determine centimetre- to metre-scale rock prisms. Interestingly, along the topmost portion of the slope, some dolines and swallow holes show an incipient coalescence, that trends parallel to the massif front and to the deformation zones related to the

  5. Isotope analyses of fossil small mammals in karstic sites

    NASA Astrophysics Data System (ADS)

    Garcia Alix, Antonio; Delgado Huertas, Antonio

    2016-04-01

    Fossil skeletal accumulations in kartstic complexes, such as caves, are quite common, especially during the Pliocene and Quaternary. These fossil assemblages are sometimes difficult to study, as specimens from different ages can be found together (time averaging). The traditional approach to study this kind of paleontological sites was taphonomic (understanding the origin and other factors affecting the bone accumulation) and/or taxonomic (systematic description of the remains). However, other kinds of analyses, such as biogeochemical techniques to reconstruct past diets and environments, are being more frequently used. Small-mammals have a wide geographical distribution, and their remains (bones and teeth) are extensively represented in the fossil record; therefore, isotopic analyses in fossil small-mammals are a powerful tool to reconstruct paleoenvironments. Field samples for small-mammal studies yield large amounts of sediment-residues that need to be reduced in the laboratory (usually by means of diluted hydrochloric or acetic acid). Therefore, samples of fossil small-mammal for isotopic analyses usually receive two different acid treatments: one to reduce the carbonate residue of the sediment, and afterwards another one to remove digenetic carbonates from the ground sample. Those treatments, along with the small size of the remains, may increase the probability of chemical fractionation during those pre-treatment stages. Those acid treatments are even more aggressive in kasrtic fossil localities, as limestone has to be dissolved to extract the small mammal remains. In this abstract, we present the results of two different treatments carried out in limestone from the Pliocene karstic locality of Moreda (Guadix Basin, Spain) and a control sample. One batch of samples were treated with a solution of 1M acetic acid-acetate calcium buffer (ph 4,5), and the rest with diluted acetic acid (at 15% concentration, Ph 2,2), which is the most used to reduce the sediments

  6. Using stable isotopes and major ions to identify hydrological processes and geochemical characteristics in a typical karstic basin, Guizhou, Southwest China.

    PubMed

    Han, Zhiwei; Tang, Changyuan; Wu, Pan; Zhang, Ruixue; Zhang, Chipeng

    2014-01-01

    The investigation of hydrological processes is very important for water resource development in karst basins. In order to understand these processes associated with complex hydrogeochemical evolution, a typical basin was chosen in Houzai, southwest China. The basin was hydrogeologically classified into three zones based on hydrogen and oxygen isotopes as well as the field surveys. Isotopic values were found to be enriched in zone 2 where paddy fields were prevailing with well-developed underground flow systems, and heavier than those in zone 1. Zone 3 was considered as the mixture of zones 1 and 2 with isotopic values falling in the range between the two zones. A conceptual hydrological model was thus proposed to reveal the probable hydrological cycle in the basin. In addition, major processes of long-term chemical weathering in the karstic basin were discussed, and reactions between water and carbonate rocks proved to be the main geochemical processes in karst aquifers.

  7. Magnetically Damped Furnace Bitter Magnet Coil 1

    NASA Technical Reports Server (NTRS)

    Bird, M. D.

    1997-01-01

    A magnet has been built by the National High Magnetic Field Laboratory for NASA on a cost reimbursement contract. The magnet is intended to demonstrate the technology and feasibility of building a magnet for space based crystal growth. A Bitter magnet (named after Francis Bitter, its inventor) was built consisting of four split coils electrically in series and hydraulically in parallel. The coils are housed in a steel vessel to reduce the fringe field and provide some on-axis field enhancement. The steel was nickel plated and Teflon coated to minimize interaction with the water cooling system. The magnet provides 0.14 T in a 184 mm bore with 3 kW of power.

  8. Bitters: Time for a New Paradigm

    PubMed Central

    McMullen, Michael K.; Whitehouse, Julie M.; Towell, Anthony

    2015-01-01

    In plant-based medical systems, bitter tasting plants play a key role in managing dyspepsia. Yet when it comes to defining their mechanism of activity, herbalists and pharmacologists are split between two theories: one involves cephalic elicited vagal responses while the other comprises purely local responses. Recent studies indicate that bitters elicit a range of cephalic responses which alter postprandial gastric phase haemodynamics. Caffeine and regular coffee (Coffea arabica semen, L.) increase heart rate whereas gentian (Gentiana lutea radix, L.) and wormwood (Artemisia absinthium herba L.) increase tonus in the vascular resistance vessels. Following meals increased cardiac activity acts to support postprandial hyperaemia and maintain systemic blood pressure. The increased vascular tonus acts in parallel with the increased cardiac activity and in normal adults this additional pressor effect results in a reduced cardiac workload. The vascular response is a sympathetic reflex, evident after 5 minutes and dose dependent. Thus gentian and wormwood elicit cephalic responses which facilitate rather than stimulate digestive activity when postprandial hyperaemia is inadequate. Encapsulated caffeine elicits cardiovascular responses indicating that gastrointestinal bitter receptors are functionally active in humans. However, neither encapsulated gentian nor wormwood elicited cardiovascular responses during the gastric phase. These findings provide the platform for a new evidence-based paradigm. PMID:26074998

  9. Bitters: Time for a New Paradigm.

    PubMed

    McMullen, Michael K; Whitehouse, Julie M; Towell, Anthony

    2015-01-01

    In plant-based medical systems, bitter tasting plants play a key role in managing dyspepsia. Yet when it comes to defining their mechanism of activity, herbalists and pharmacologists are split between two theories: one involves cephalic elicited vagal responses while the other comprises purely local responses. Recent studies indicate that bitters elicit a range of cephalic responses which alter postprandial gastric phase haemodynamics. Caffeine and regular coffee (Coffea arabica semen, L.) increase heart rate whereas gentian (Gentiana lutea radix, L.) and wormwood (Artemisia absinthium herba L.) increase tonus in the vascular resistance vessels. Following meals increased cardiac activity acts to support postprandial hyperaemia and maintain systemic blood pressure. The increased vascular tonus acts in parallel with the increased cardiac activity and in normal adults this additional pressor effect results in a reduced cardiac workload. The vascular response is a sympathetic reflex, evident after 5 minutes and dose dependent. Thus gentian and wormwood elicit cephalic responses which facilitate rather than stimulate digestive activity when postprandial hyperaemia is inadequate. Encapsulated caffeine elicits cardiovascular responses indicating that gastrointestinal bitter receptors are functionally active in humans. However, neither encapsulated gentian nor wormwood elicited cardiovascular responses during the gastric phase. These findings provide the platform for a new evidence-based paradigm.

  10. Volatile and sensory profiling of cocktail bitters.

    PubMed

    Johnson, Arielle J; Heymann, Hildegarde; Ebeler, Susan E

    2015-07-15

    Aromatic cocktail bitters are derived from the alcoholic extraction of a variety of plant materials and are used as additives in mixed drinks to enhance aroma and flavor. In this study sixteen commercial bitters were analyzed using volatile (GC-MS) and sensory profiling and multivariate statistics including Principal Component Analysis (PCA) and Partial Least Squares Regression (PLS). The samples differed significantly in their citrus, celery, and spice characteristics. 148 volatile compounds were tentatively identified and the composition varied significantly with the type of bitters sample evaluated. PLS analysis showed that the volatile data correlated well overall to the sensory data, explaining 60% of the overall variability in the dataset. Primary aldehydes and phenylpropanoids were most closely related to green and spice-related sensory descriptors. However, the sensory impact of terpenoid compounds was difficult to predict in many cases. This may be due to the wide range of aroma qualities associated with terpenes as well as to concentration, synergistic or masking effects. PMID:25722175

  11. Bitters: Time for a New Paradigm.

    PubMed

    McMullen, Michael K; Whitehouse, Julie M; Towell, Anthony

    2015-01-01

    In plant-based medical systems, bitter tasting plants play a key role in managing dyspepsia. Yet when it comes to defining their mechanism of activity, herbalists and pharmacologists are split between two theories: one involves cephalic elicited vagal responses while the other comprises purely local responses. Recent studies indicate that bitters elicit a range of cephalic responses which alter postprandial gastric phase haemodynamics. Caffeine and regular coffee (Coffea arabica semen, L.) increase heart rate whereas gentian (Gentiana lutea radix, L.) and wormwood (Artemisia absinthium herba L.) increase tonus in the vascular resistance vessels. Following meals increased cardiac activity acts to support postprandial hyperaemia and maintain systemic blood pressure. The increased vascular tonus acts in parallel with the increased cardiac activity and in normal adults this additional pressor effect results in a reduced cardiac workload. The vascular response is a sympathetic reflex, evident after 5 minutes and dose dependent. Thus gentian and wormwood elicit cephalic responses which facilitate rather than stimulate digestive activity when postprandial hyperaemia is inadequate. Encapsulated caffeine elicits cardiovascular responses indicating that gastrointestinal bitter receptors are functionally active in humans. However, neither encapsulated gentian nor wormwood elicited cardiovascular responses during the gastric phase. These findings provide the platform for a new evidence-based paradigm. PMID:26074998

  12. Metabolism of hop-derived bitter acids.

    PubMed

    Cattoor, Ko; Dresel, Michael; De Bock, Lies; Boussery, Koen; Van Bocxlaer, Jan; Remon, Jean-Paul; De Keukeleire, Denis; Deforce, Dieter; Hofmann, Thomas; Heyerick, Arne

    2013-08-21

    In this study, in vitro metabolism of hop-derived bitter acids was investigated. Besides their well-known use as bitter compounds in beer, in several studies, bioactive properties have been related to these types of molecules. However, scientific data on the absorption, distribution, metabolism, and excretion aspects of these compounds are limited. More specific, in this study, α-acids, β-acids, and iso-α-acids were incubated with rabbit microsomes, and fractions were subjected to LC-MS/MS analysis for identification of oxidative biotransformation products. Metabolism of β-acids was mainly characterized by conversion into hulupones and the formation of a series of tricyclic oxygenated products. The most important metabolites of α-acids were identified as humulinones and hulupones. Iso-α-acids were found to be primarly metabolized into cis- and trans-humulinic acids, next to oxidized alloiso-α-acids. Interestingly, the phase I metabolites were highly similar to the oxidative degradation products in beer. These findings show a first insight into the metabolites of hop-derived bitter acids and could have important practical implications in the bioavailability aspects of these compounds, following ingestion of hop-based food products and nutraceuticals.

  13. Plant science. Biosynthesis, regulation, and domestication of bitterness in cucumber.

    PubMed

    Shang, Yi; Ma, Yongshuo; Zhou, Yuan; Zhang, Huimin; Duan, Lixin; Chen, Huiming; Zeng, Jianguo; Zhou, Qian; Wang, Shenhao; Gu, Wenjia; Liu, Min; Ren, Jinwei; Gu, Xingfang; Zhang, Shengping; Wang, Ye; Yasukawa, Ken; Bouwmeester, Harro J; Qi, Xiaoquan; Zhang, Zhonghua; Lucas, William J; Huang, Sanwen

    2014-11-28

    Cucurbitacins are triterpenoids that confer a bitter taste in cucurbits such as cucumber, melon, watermelon, squash, and pumpkin. These compounds discourage most pests on the plant and have also been shown to have antitumor properties. With genomics and biochemistry, we identified nine cucumber genes in the pathway for biosynthesis of cucurbitacin C and elucidated four catalytic steps. We discovered transcription factors Bl (Bitter leaf) and Bt (Bitter fruit) that regulate this pathway in leaves and fruits, respectively. Traces in genomic signatures indicated that selection imposed on Bt during domestication led to derivation of nonbitter cucurbits from their bitter ancestors. PMID:25430763

  14. Bitter Gourd; A vegetable to Improve Human Health

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Vegetables play a significant role in human nutrition, especially as vitamin sources (i.e., A, B6, C, E, thiamine, and niacin), minerals, and dietary fiber. These compounds are associated with reduced risk of cancer, cardiovascular disease, and other chronic diseases. Bitter gourd (syn. bitter mel...

  15. Bitter Taste Stimuli Induce Differential Neural Codes in Mouse Brain

    PubMed Central

    Wilson, David M.; Boughter, John D.; Lemon, Christian H.

    2012-01-01

    A growing literature suggests taste stimuli commonly classified as “bitter” induce heterogeneous neural and perceptual responses. Here, the central processing of bitter stimuli was studied in mice with genetically controlled bitter taste profiles. Using these mice removed genetic heterogeneity as a factor influencing gustatory neural codes for bitter stimuli. Electrophysiological activity (spikes) was recorded from single neurons in the nucleus tractus solitarius during oral delivery of taste solutions (26 total), including concentration series of the bitter tastants quinine, denatonium benzoate, cycloheximide, and sucrose octaacetate (SOA), presented to the whole mouth for 5 s. Seventy-nine neurons were sampled; in many cases multiple cells (2 to 5) were recorded from a mouse. Results showed bitter stimuli induced variable gustatory activity. For example, although some neurons responded robustly to quinine and cycloheximide, others displayed concentration-dependent activity (p<0.05) to quinine but not cycloheximide. Differential activity to bitter stimuli was observed across multiple neurons recorded from one animal in several mice. Across all cells, quinine and denatonium induced correlated spatial responses that differed (p<0.05) from those to cycloheximide and SOA. Modeling spatiotemporal neural ensemble activity revealed responses to quinine/denatonium and cycloheximide/SOA diverged during only an early, at least 1 s wide period of the taste response. Our findings highlight how temporal features of sensory processing contribute differences among bitter taste codes and build on data suggesting heterogeneity among “bitter” stimuli, data that challenge a strict monoguesia model for the bitter quality. PMID:22844505

  16. Introduction of wavelet analyses to rainfall/runoffs relationship for a karstic basin: the case of Licq-Atherey karstic system (France).

    PubMed

    Labat, D; Ababou, R; Mangin, A

    2001-01-01

    Karstic systems are highly heterogeneous geological formations characterized by a multiscale temporal and spatial hydrologic behavior with more or less localized temporal and spatial structures. Classical correlation and spectral analyses cannot take into account these properties. Therefore, it is proposed to introduce a new kind of transformation: the wavelet transform. Here we focus particularly on the use of wavelets to study temporal behavior of local precipitation and watershed runoffs from a part of the karstic system. In the first part of the paper, a brief mathematical overview of the continuous Morlet wavelet transform and of the multiresolution analysis is presented. An analogy with spectral analyses allows the introduction of concepts such as wavelet spectrum and cross-spectrum. In the second part, classical methods (spectral and correlation analyses) and wavelet transforms are applied and compared for daily rainfall rates and runoffs measured on a French karstic watershed (Pyrénées) over a period of 30 years. Different characteristic time scales of the rainfall and runoff processes are determined. These time scales are typically on the order of a few days for floods, but they also include significant half-year and one-year components and multi-annual components. The multiresolution cross-analysis also provides a new interpretation of the impulse response of the system. To conclude, wavelet transforms provide a valuable amount of information, which may be now taken into account in both temporal and spatially distributed karst modeling of precipitation and runoff. PMID:11447860

  17. GWAS of human bitter taste perception identifies new loci and reveals additional complexity of bitter taste genetics

    PubMed Central

    Ledda, Mirko; Kutalik, Zoltán; Souza Destito, Maria C.; Souza, Milena M.; Cirillo, Cintia A.; Zamboni, Amabilene; Martin, Nathalie; Morya, Edgard; Sameshima, Koichi; Beckmann, Jacques S.; le Coutre, Johannes; Bergmann, Sven; Genick, Ulrich K.

    2014-01-01

    Human perception of bitterness displays pronounced interindividual variation. This phenotypic variation is mirrored by equally pronounced genetic variation in the family of bitter taste receptor genes. To better understand the effects of common genetic variations on human bitter taste perception, we conducted a genome-wide association study on a discovery panel of 504 subjects and a validation panel of 104 subjects from the general population of São Paulo in Brazil. Correction for general taste-sensitivity allowed us to identify a SNP in the cluster of bitter taste receptors on chr12 (10.88– 11.24 Mb, build 36.1) significantly associated (best SNP: rs2708377, P = 5.31 × 10−13, r2 = 8.9%, β = −0.12, s.e. = 0.016) with the perceived bitterness of caffeine. This association overlaps with—but is statistically distinct from—the previously identified SNP rs10772420 influencing the perception of quinine bitterness that falls in the same bitter taste cluster. We replicated this association to quinine perception (P = 4.97 × 10−37, r2 = 23.2%, β = 0.25, s.e. = 0.020) and additionally found the effect of this genetic locus to be concentration specific with a strong impact on the perception of low, but no impact on the perception of high concentrations of quinine. Our study, thus, furthers our understanding of the complex genetic architecture of bitter taste perception. PMID:23966204

  18. GWAS of human bitter taste perception identifies new loci and reveals additional complexity of bitter taste genetics.

    PubMed

    Ledda, Mirko; Kutalik, Zoltán; Souza Destito, Maria C; Souza, Milena M; Cirillo, Cintia A; Zamboni, Amabilene; Martin, Nathalie; Morya, Edgard; Sameshima, Koichi; Beckmann, Jacques S; le Coutre, Johannes; Bergmann, Sven; Genick, Ulrich K

    2014-01-01

    Human perception of bitterness displays pronounced interindividual variation. This phenotypic variation is mirrored by equally pronounced genetic variation in the family of bitter taste receptor genes. To better understand the effects of common genetic variations on human bitter taste perception, we conducted a genome-wide association study on a discovery panel of 504 subjects and a validation panel of 104 subjects from the general population of São Paulo in Brazil. Correction for general taste-sensitivity allowed us to identify a SNP in the cluster of bitter taste receptors on chr12 (10.88- 11.24 Mb, build 36.1) significantly associated (best SNP: rs2708377, P = 5.31 × 10(-13), r(2) = 8.9%, β = -0.12, s.e. = 0.016) with the perceived bitterness of caffeine. This association overlaps with-but is statistically distinct from-the previously identified SNP rs10772420 influencing the perception of quinine bitterness that falls in the same bitter taste cluster. We replicated this association to quinine perception (P = 4.97 × 10(-37), r(2) = 23.2%, β = 0.25, s.e. = 0.020) and additionally found the effect of this genetic locus to be concentration specific with a strong impact on the perception of low, but no impact on the perception of high concentrations of quinine. Our study, thus, furthers our understanding of the complex genetic architecture of bitter taste perception.

  19. Sensory quality of functional beverages: bitterness perception and bitter masking of olive leaf extract fortified fruit smoothies.

    PubMed

    Kranz, Peter; Braun, Nina; Schulze, Nadine; Kunz, Benno

    2010-08-01

    Olive leaf extract (OLE) contains high amounts of oleuropein and hydroxytyrosol. The antioxidant capacity of these polyphenols makes OLE a promising ingredient for functional food. OLE causes very strong bitterness perception and can therefore only be formulated in low concentrations. In this research, bitter detection and recognition thresholds of OLE-fortified fruit smoothies were determined by a trained sensory panel (n = 11). Masking of the OLE's bitter taste was investigated with addition of sodium cyclamate, sodium chloride, and sucrose by means of a standardized ranking method and a scale test. Detection (5.78 mg/100 g) and recognition thresholds (8.05 mg/100 g) of OLE polyphenols confirmed the low formulation limits when bitterness was not masked by other substances. At higher polyphenol levels of 20 mg/100 g, sodium cyclamate and sucrose were able to reduce bitter taste perception by 39.9% and 24.9%, respectively, whereas sodium chloride could not effectively mask bitterness. Practical Application: Development of functional food poses new challenges for the food industry. A major problem in this field is the high bitterness of natural polyphenol-containing extracts with potential health benefits. This research was conducted to understand the sensory impact of olive leaf extract (OLE), a novel food ingredient with very bitter taste. In product development, the data of this research can be considered for formulation limits and the general sensory quality of OLE-fortified food and beverages.

  20. Making Early Modern Medicine: Reproducing Swedish Bitters.

    PubMed

    Ahnfelt, Nils-Otto; Fors, Hjalmar

    2016-05-01

    Historians of science and medicine have rarely applied themselves to reproducing the experiments and practices of medicine and pharmacy. This paper delineates our efforts to reproduce "Swedish Bitters," an early modern composite medicine in wide European use from the 1730s to the present. In its original formulation, it was made from seven medicinal simples: aloe, rhubarb, saffron, myrrh, gentian, zedoary and agarikon. These were mixed in alcohol together with some theriac, a composite medicine of classical origin. The paper delineates the compositional history of Swedish Bitters and the medical rationale underlying its composition. It also describes how we go about to reproduce the medicine in a laboratory using early modern pharmaceutical methods, and analyse it using contemporary methods of pharmaceutical chemistry. Our aim is twofold: first, to show how reproducing medicines may provide a path towards a deeper understanding of the role of sensual and practical knowledge in the wider context of early modern medical culture; and second, how it may yield interesting results from the point of view of contemporary pharmaceutical science.

  1. Automatic detection of karstic sinkholes in seismic 3D images using circular Hough transform

    NASA Astrophysics Data System (ADS)

    Heydari Parchkoohi, Mostafa; Keshavarz Farajkhah, Nasser; Salimi Delshad, Meysam

    2015-10-01

    More than 30% of hydrocarbon reservoirs are reported in carbonates that mostly include evidence of fractures and karstification. Generally, the detection of karstic sinkholes prognosticate good quality hydrocarbon reservoirs where looser sediments fill the holes penetrating hard limestone and the overburden pressure on infill sediments is mostly tolerated by their sturdier surrounding structure. They are also useful for the detection of erosional surfaces in seismic stratigraphic studies and imply possible relative sea level fall at the time of establishment. Karstic sinkholes are identified straightforwardly by using seismic geometric attributes (e.g. coherency, curvature) in which lateral variations are much more emphasized with respect to the original 3D seismic image. Then, seismic interpreters rely on their visual skills and experience in detecting roughly round objects in seismic attribute maps. In this paper, we introduce an image processing workflow to enhance selective edges in seismic attribute volumes stemming from karstic sinkholes and finally locate them in a high quality 3D seismic image by using circular Hough transform. Afterwards, we present a case study from an on-shore oilfield in southwest Iran, in which the proposed algorithm is applied and karstic sinkholes are traced.

  2. AQUIFER TRANSMISSIVITY

    EPA Science Inventory

    Evaluation of groundwater resources requires the knowledge of the capacity of aquifers to store and transmit ground water. This requires estimates of key hydraulic parameters, such as the transmissivity, among others. The transmissivity T (m2/sec) is a hydrauli...

  3. Characterization of a soluble phosphatidic acid phosphatase in bitter melon (Momordica charantia)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Momordica charantia is often called bitter melon, bitter gourd or bitter squash because its fruit has a bitter taste. The fruit has been widely used as vegetable and herbal medicine. Alpha-eleostearic acid is the major fatty acid in the seeds, but little is known about its biosynthesis. As an initia...

  4. Electrophysiological responses to bitter stimuli in primate cortex.

    PubMed

    Scott, T R; Giza, B K; Yan, J

    1998-11-30

    Studies investigating fine details of gustatory coding in the domain of each basic taste quality have been completed for sweet, salt, and sour stimuli. In the present experiment, we used chemicals that humans describe as predominantly bitter. We recorded the activity of 50 taste neurons in insular cortex of two cynomolgus macaques. Stimuli were water, fruit juice, glucose, NaCl, HCl, and 16 bitter solutions. In a multidimensional taste space the 16 bitter stimuli formed a coherent cluster composed of three main subgroups: (1) QHCl, phenylalanine, theophylline, caffeine, propyl-thiouracil (PROP), and phenylthiocarbamide (PTC), all of which humans describe as rather purely bitter, (2) MgCl2, CaCl2, NH4Cl, and arginine, which humans describe as salty-bitter, and (3) urea, cysteine, and vitamin B1, which are described as sour-bitter. Vitamin B2, histidine and nicotine were in the center of the bitter cluster. Human descriptions of taste qualities conformed well to the presumed quality of each stimulus as inferred from its position in the multidimensional space (MDS), reinforcing the use of the macaque as a neural model for human gustation.

  5. Identification of Bitterness-Masking Compounds from Cheese

    PubMed Central

    2012-01-01

    Bitterness-masking compounds were identified in a natural white mold cheese. The oily fraction of the cheese was extracted and further fractionated by using silica gel column chromatography. The four fractions obtained were characterized by thin-layer chromatography and nuclear magnetic resonance spectroscopy. The fatty acid-containing fraction was found to have the highest bitterness-masking activity against quinine hydrochloride. Bitterness-masking activity was quantitated using a method based on subjective equivalents. At 0.5 mM, the fatty acid mixture, which had a composition similar to that of cheese, suppressed the bitterness of 0.008% quinine hydrochloride to be equivalent to that of 0.0049–0.0060% and 0.5 mM oleic acid to that of 0.0032–0.0038% solution. The binding potential between oleic acid and the bitter compounds was estimated by isothermal titration calorimetry. These results suggest that oleic acid masked bitterness by forming a complex with the bitter compounds. PMID:22502602

  6. Bitterness of sweeteners as a function of concentration.

    PubMed

    Schiffman, S S; Booth, B J; Losee, M L; Pecore, S D; Warwick, Z S

    1995-01-01

    Sixteen trained tasters provided sweetness and bitterness intensity ratings for 19 compounds including: acesulfame-K, alitame, aspartame, fructose, glucose, glycine, lactitol, maltitol, monoammonium glycyrrhizinate, neohesperidin dihydrochalcone, neosugar (fructo-oligosaccharide), palatinit (isomalt), rebaudioside-A, sodium cyclamate, sodium saccharin, stevioside, sucralose, sucrose, and thaumatin. With increasing concentration, high-potency sweeteners including acesulfame-K, neohesperidin dihydrochalcone, sodium saccharin, rebaudioside-A, and stevioside tended to become more bitter. Low-potency sweeteners including fructose, sucrose, and lactitol tended to become less bitter with increasing concentration.

  7. NMR phase noise in bitter magnets.

    PubMed

    Sigmund, E E; Calder, E S; Thomas, G W; Mitrović, V F; Bachman, H N; Halperin, W P; Kuhns, P L; Reyes, A P

    2001-02-01

    We have studied the temporal instability of a high field resistive Bitter magnet through nuclear magnetic resonance (NMR). This instability leads to transverse spin decoherence in repeated and accumulated NMR experiments as is normally performed during signal averaging. We demonstrate this effect via Hahn echo and Carr--Purcell--Meiboom--Gill (CPMG) transverse relaxation experiments in a 23-T resistive magnet. Quantitative analysis was found to be consistent with separate measurements of the magnetic field frequency fluctuation spectrum, as well as with independent NMR experiments performed in a magnetic field with a controlled instability. Finally, the CPMG sequence with short pulse delays is shown to be successful in recovering the intrinsic spin--spin relaxation even in the presence of magnetic field temporal instability.

  8. Functional characterization of human bitter taste receptors

    PubMed Central

    Sainz, Eduardo; Cavenagh, Margaret M.; Gutierrez, Joanne; Battey, James F.; Northup, John K.; Sullivan, Susan L.

    2007-01-01

    The T2Rs belong to a multi-gene family of G-protein-coupled receptors responsible for the detection of ingested bitter-tasting compounds. The T2Rs are conserved among mammals with the human and mouse gene families consisting of about 25 members. In the present study we address the signalling properties of human and mouse T2Rs using an in vitro reconstitution system in which both the ligands and G-proteins being assayed can be manipulated independently and quantitatively assessed. We confirm that the mT2R5, hT2R43 and hT2R47 receptors respond selectively to micromolar concentrations of cycloheximide, aristolochic acid and denatonium respectively. We also demonstrate that hT2R14 is a receptor for aristolochic acid and report the first characterization of the ligand specificities of hT2R7, which is a broadly tuned receptor responding to strychnine, quinacrine, chloroquine and papaverine. Using these defined ligand–receptor interactions, we assayed the ability of the ligand-activated T2Rs to catalyse GTP binding on divergent members of the Gα family including three members of the Gαi subfamily (transducin, Gαi1 and Gαo) as well as Gαs and Gαq. The T2Rs coupled with each of the three Gαi members tested. However, none of the T2Rs coupled to either Gαs or Gαq, suggesting the T2Rs signal primarily through Gαi-mediated signal transduction pathways. Furthermore, we observed different G-protein selectivities among the T2Rs with respect to both Gαi subunits and Gβγ dimers, suggesting that bitter taste is transduced by multiple G-proteins that may differ among the T2Rs. PMID:17253962

  9. Bitter peptide from hemoglobin hydrolysate: isolation and characterization.

    PubMed

    Aubes-Dufau, I; Capdevielle, J; Seris, J L; Combes, D

    1995-05-01

    Two separation methods, ultrafiltration and 2-butanol extraction, have shown that a peptide is the major agent responsible for bitterness in peptic hemoglobin hydrolysates. It was easily purified from these complex mixtures by specific hydrophobic adsorption on Superose 12, a gel-filtration column, which could constitute an original and interesting method for bitterness detection. The bitter peptide which corresponded to VV-hemorphin 7, the fragment 32-40 of the beta chain of bovine hemoglobin, is first generated during proteolysis, then hydrolysed by pepsin. It exhibited a strong bitterness at 0.25 mM equivalent to 0.073 mM quinine sulfate or 21 mM caffeine.

  10. Identification of bitter peptides in aged cheddar cheese.

    PubMed

    Karametsi, Konstantinia; Kokkinidou, Smaro; Ronningen, Ian; Peterson, Devin G

    2014-08-13

    The compounds responsible for the bitter taste of aged "sharp" Cheddar cheese were characterized. Sensory-guided fractionation techniques using gel permeation chromatography and multi-dimension semi-preparative reversed-phase high-performance liquid chromatography revealed the presence of multiple bitter compounds. The compounds with the highest perceived bitterness intensity were identified by tandem mass spectrometry de novo peptide sequencing as GPVRGPFPIIV, YQEPVLGPVRGPFPI, MPFPKYPVEP, MAPKHKEMPFPKYPVEPF, and APHGKEMPFPKYPVEPF; all originated from β-casein. Subsequent quantitative liquid chromatography-tandem mass spectrometry analysis reported that the concentrations of GPVRGPFPIIV, YQEPVLGPVRGPFPI, and MPFPKYPVEP increased during maturation by 28.7-, 3.1-, and 1.8-fold, respectively. When directly compared to young "mild" Cheddar, APHGKEMPFPKYPVEPF was reported only in the sharp Cheddar cheese, whereas the concentration of MAPKHKEMPFPKYPVEPF did not change. Further taste re-engineering sensory experiments confirmed the importance of the identified peptides to the bitterness of sharp Cheddar. The bitter intensity of the aged "sharp" Cheddar model (mild Cheddar with equivalent concentrations of the five bitter peptides in the sharp sample) was rated as not significantly different from the authentic sharp Cheddar cheese. Among the five peptides, GPVRGPFPIIV was reported to be the main contributor to the bitterness intensity of sharp Cheddar. Furthermore, a difference from control sensory test also confirmed the significance of the bitter taste to the overall perception of aged Cheddar flavor. The sharp Cheddar model was reported to be significantly more similar to aged "sharp" Cheddar in comparison to the young "mild" Cheddar cheese sample. PMID:25075877

  11. Anthropogenic contaminants as tracers in an urbanizing karst aquifer

    NASA Astrophysics Data System (ADS)

    Mahler, Barbara; Massei, Nicolas

    2007-04-01

    Karst aquifers are uniquely vulnerable to contamination. In the Barton Springs segment of the karstic Edwards aquifer (Texas, U.S.A.), urban contaminants such as pesticides and volatile organic compounds frequently are detected in spring base flow. To determine whether contaminant concentrations change in response to storms, and if they therefore might act as tracers of focused recharge, samples were collected from Barton Springs at closely spaced intervals following three storms. Two herbicides (atrazine and simazine), two insecticides (carbaryl and diazinon), and a solvent (tetrachloroethene) described breakthrough curves over a 1-week period following one or more storms. The breakthrough curves were decomposed into two to five log-normal subcurves, which were interpreted as representing pulses of contaminants moving through the aquifer. Each subcurve could be used in the same way as an artificial tracer to determine travel time to and recovery at the spring. The contaminants have several advantages over artificial tracers: they represent the actual compounds of interest, they are injected essentially simultaneously at several points, and they are injected under those conditions when transport is of the most interest, i.e., following storms. The response of storm discharge, specific conductance, and contaminant loading at the spring depended on initial aquifer flow conditions, which varied from very low (spring discharge of 0.48 m 3/s) to high (spring discharge of 2.7 m 3/s): concentrations and recovery were the highest when initial aquifer flow conditions were low. This behavior provides information about aquifer structure and the influence of aquifer flow condition on transport properties.

  12. Anthropogenic contaminants as tracers in an urbanizing karst aquifer.

    PubMed

    Mahler, Barbara; Massei, Nicolas

    2007-04-01

    Karst aquifers are uniquely vulnerable to contamination. In the Barton Springs segment of the karstic Edwards aquifer (Texas, U.S.A.), urban contaminants such as pesticides and volatile organic compounds frequently are detected in spring base flow. To determine whether contaminant concentrations change in response to storms, and if they therefore might act as tracers of focused recharge, samples were collected from Barton Springs at closely spaced intervals following three storms. Two herbicides (atrazine and simazine), two insecticides (carbaryl and diazinon), and a solvent (tetrachloroethene) described breakthrough curves over a 1-week period following one or more storms. The breakthrough curves were decomposed into two to five log-normal subcurves, which were interpreted as representing pulses of contaminants moving through the aquifer. Each subcurve could be used in the same way as an artificial tracer to determine travel time to and recovery at the spring. The contaminants have several advantages over artificial tracers: they represent the actual compounds of interest, they are injected essentially simultaneously at several points, and they are injected under those conditions when transport is of the most interest, i.e., following storms. The response of storm discharge, specific conductance, and contaminant loading at the spring depended on initial aquifer flow conditions, which varied from very low (spring discharge of 0.48 m3/s) to high (spring discharge of 2.7 m3/s): concentrations and recovery were the highest when initial aquifer flow conditions were low. This behavior provides information about aquifer structure and the influence of aquifer flow condition on transport properties.

  13. Anthropogenic contaminants as tracers in an urbanizing karst aquifer

    USGS Publications Warehouse

    Mahler, B.; Massei, N.

    2007-01-01

    Karst aquifers are uniquely vulnerable to contamination. In the Barton Springs segment of the karstic Edwards aquifer (Texas, U.S.A.), urban contaminants such as pesticides and volatile organic compounds frequently are detected in spring base flow. To determine whether contaminant concentrations change in response to storms, and if they therefore might act as tracers of focused recharge, samples were collected from Barton Springs at closely spaced intervals following three storms. Two herbicides (atrazine and simazine), two insecticides (carbaryl and diazinon), and a solvent (tetrachloroethene) described breakthrough curves over a 1-week period following one or more storms. The breakthrough curves were decomposed into two to five log-normal subcurves, which were interpreted as representing pulses of contaminants moving through the aquifer. Each subcurve could be used in the same way as an artificial tracer to determine travel time to and recovery at the spring. The contaminants have several advantages over artificial tracers: they represent the actual compounds of interest, they are injected essentially simultaneously at several points, and they are injected under those conditions when transport is of the most interest, i.e., following storms. The response of storm discharge, specific conductance, and contaminant loading at the spring depended on initial aquifer flow conditions, which varied from very low (spring discharge of 0.48??m3/s) to high (spring discharge of 2.7??m3/s): concentrations and recovery were the highest when initial aquifer flow conditions were low. This behavior provides information about aquifer structure and the influence of aquifer flow condition on transport properties. ?? 2006 Elsevier B.V. All rights reserved.

  14. Behavioral Analysis of Bitter Taste Perception in Drosophila Larvae.

    PubMed

    Kim, Haein; Choi, Min Sung; Kang, KyeongJin; Kwon, Jae Young

    2016-01-01

    Insect larvae, which recognize food sources through chemosensory cues, are a major source of global agricultural loss. Gustation is an important factor that determines feeding behavior, and the gustatory receptors (Grs) act as molecular receptors that recognize diverse chemicals in gustatory receptor neurons (GRNs). The behavior of Drosophila larvae is relatively simpler than the adult fly, and a gustatory receptor-to-neuron map was established in a previous study of the major external larval head sensory organs. Here, we extensively study the bitter taste responses of larvae using 2-choice behavioral assays. First, we tested a panel of 23 candidate bitter compounds to compare the behavioral responses of larvae and adults. We define 9 bitter compounds which elicit aversive behavior in a dose-dependent manner. A functional map of the larval GRNs was constructed with the use of Gr-GAL4 lines that drive expression of UAS-tetanus toxin and UAS-VR1 in specific gustatory neurons to identify bitter tastants-GRN combinations by suppressing and activating discrete subsets of taste neurons, respectively. Our results suggest that many gustatory neurons act cooperatively in larval bitter sensing, and that these neurons have different degrees of responsiveness to different bitter compounds.

  15. The Pharmacochaperone Activity of Quinine on Bitter Taste Receptors

    PubMed Central

    Upadhyaya, Jasbir D.; Chakraborty, Raja; Shaik, Feroz A.; Jaggupilli, Appalaraju; Bhullar, Rajinder P.; Chelikani, Prashen

    2016-01-01

    Bitter taste is one of the five basic taste sensations which is mediated by 25 bitter taste receptors (T2Rs) in humans. The mechanism of bitter taste signal transduction is not yet elucidated. The cellular processes underlying T2R desensitization including receptor internalization, trafficking and degradation are yet to be studied. Here, using a combination of molecular and pharmacological techniques we show that T2R4 is not internalized upon agonist treatment. Pretreatment with bitter agonist quinine led to a reduction in subsequent quinine-mediated calcium responses to 35 ± 5% compared to the control untreated cells. Interestingly, treatment with different bitter agonists did not cause internalization of T2R4. Instead, quinine treatment led to a 2-fold increase in T2R4 cell surface expression which was sensitive to Brefeldin A, suggesting a novel pharmacochaperone activity of quinine. This phenomenon of chaperone activity of quinine was also observed for T2R7, T2R10, T2R39 and T2R46. Our results suggest that the observed action of quinine for these T2Rs is independent of its agonist activity. This study provides novel insights into the pharmacochaperone activity of quinine and possible mechanism of T2R desensitization, which is of fundamental importance in understanding the mechanism of bitter taste signal transduction. PMID:27223611

  16. Identification of bitter compounds in whole wheat bread crumb.

    PubMed

    Bin, Qing; Peterson, Devin G

    2016-07-15

    Consumer acceptability of whole wheat foods is challenged by negative bitter flavour attributes. In this study, bitter compounds in whole wheat bread crumb were investigated. Utilising sensory-guided multi-dimensional fractionation techniques, the compounds with the highest bitterness intensity in the crumb were purified and identified by LC-MS-ToF and NMR techniques. The main bitter compounds were reported to be L-tryptophan, Wessely-Moser isomers apigenin-6-C-galactoside-8-C-arabinoside & apigenin-6-C-arabinoside-8-C-galactoside, and 9,12,13-trihydroxy-trans-10-octadecenoic acid (pinellic acid). Sensory recombination experiments of the bitter compounds formulated at the concentrations determined in expectorated saliva after bread mastication indicated pinellic acid had the greatest contribution to the bitterness perception of the crumb. Quantitative analysis of pinellic acid in the raw flour was reported to be inherently low compared to bread; the concentration increased more than 30-fold after flour hydration and baking. PMID:26948582

  17. Behavioral Analysis of Bitter Taste Perception in Drosophila Larvae.

    PubMed

    Kim, Haein; Choi, Min Sung; Kang, KyeongJin; Kwon, Jae Young

    2016-01-01

    Insect larvae, which recognize food sources through chemosensory cues, are a major source of global agricultural loss. Gustation is an important factor that determines feeding behavior, and the gustatory receptors (Grs) act as molecular receptors that recognize diverse chemicals in gustatory receptor neurons (GRNs). The behavior of Drosophila larvae is relatively simpler than the adult fly, and a gustatory receptor-to-neuron map was established in a previous study of the major external larval head sensory organs. Here, we extensively study the bitter taste responses of larvae using 2-choice behavioral assays. First, we tested a panel of 23 candidate bitter compounds to compare the behavioral responses of larvae and adults. We define 9 bitter compounds which elicit aversive behavior in a dose-dependent manner. A functional map of the larval GRNs was constructed with the use of Gr-GAL4 lines that drive expression of UAS-tetanus toxin and UAS-VR1 in specific gustatory neurons to identify bitter tastants-GRN combinations by suppressing and activating discrete subsets of taste neurons, respectively. Our results suggest that many gustatory neurons act cooperatively in larval bitter sensing, and that these neurons have different degrees of responsiveness to different bitter compounds. PMID:26512069

  18. The Pharmacochaperone Activity of Quinine on Bitter Taste Receptors.

    PubMed

    Upadhyaya, Jasbir D; Chakraborty, Raja; Shaik, Feroz A; Jaggupilli, Appalaraju; Bhullar, Rajinder P; Chelikani, Prashen

    2016-01-01

    Bitter taste is one of the five basic taste sensations which is mediated by 25 bitter taste receptors (T2Rs) in humans. The mechanism of bitter taste signal transduction is not yet elucidated. The cellular processes underlying T2R desensitization including receptor internalization, trafficking and degradation are yet to be studied. Here, using a combination of molecular and pharmacological techniques we show that T2R4 is not internalized upon agonist treatment. Pretreatment with bitter agonist quinine led to a reduction in subsequent quinine-mediated calcium responses to 35 ± 5% compared to the control untreated cells. Interestingly, treatment with different bitter agonists did not cause internalization of T2R4. Instead, quinine treatment led to a 2-fold increase in T2R4 cell surface expression which was sensitive to Brefeldin A, suggesting a novel pharmacochaperone activity of quinine. This phenomenon of chaperone activity of quinine was also observed for T2R7, T2R10, T2R39 and T2R46. Our results suggest that the observed action of quinine for these T2Rs is independent of its agonist activity. This study provides novel insights into the pharmacochaperone activity of quinine and possible mechanism of T2R desensitization, which is of fundamental importance in understanding the mechanism of bitter taste signal transduction. PMID:27223611

  19. Multiple technologies applied to characterization of the porosity and permeability of the Biscayne aquifer, Florida

    USGS Publications Warehouse

    Cunningham, K.J.; Sukop, M.C.

    2011-01-01

    Research is needed to determine how seepage-control actions planned by the Comprehensive Everglades Restoration Plan (CERP) will affect recharge, groundwater flow, and discharge within the dual-porosity karstic Biscayne aquifer where it extends eastward from the Everglades to Biscayne Bay. A key issue is whether the plan can be accomplished without causing urban flooding in adjacent populated areas and diminishing coastal freshwater flow needed in the restoration of the ecologic systems. Predictive simulation of groundwater flow is a prudent approach to understanding hydrologic change and potential ecologic impacts. A fundamental problem to simulation of karst groundwater flow is how best to represent aquifer heterogeneity. Currently, U.S. Geological Survey (USGS) researchers and academic partners are applying multiple innovative technologies to characterize the spatial distribution of porosity and permeability within the Biscayne aquifer.

  20. New species of Blaesodactylus (Squamata: Gekkonidae) from Tsingy karstic outcrops in Ankarana National Park, northern Madagascar.

    PubMed

    Jono, Teppei; Bauer, Aaron M; Brennan, Ian; Mori, Akira

    2015-01-01

    We describe a new gecko of the genus Blaesodactylus from a karstic outcrop in deciduous dry forest of Ankarana National Park, northern Madagascar. Blaesodactylus microtuberculatus sp. nov., the fifth recognized species of Blaesodactylus, is distinguished from all other congeners, B. ambonihazo, B. antongilensis, B. boivini and B. sakalava by a combination of small, homogeneous gular granules, unspotted venter and lack of tubercles on distal part of original tail. Mitochondrial (ND2 and ND4) and nuclear (RAG-1) DNA identify a consistent divergence between B. microtuberculatus and its allotopic sister species B. boivini. We highlight habitat partitioning in these allotopic congeners where Blaesodactylus microtuberculatus inhabits karstic outcrops in Tsingy massif, and B. boivini dwells on tree trunks in deciduous dry forest.

  1. Spatial organization of the impulse response in a karst aquifer

    NASA Astrophysics Data System (ADS)

    Delbart, C.; Valdés, D.; Barbecot, F.; Tognelli, A.; Couchoux, L.

    2016-06-01

    Karst aquifers are characterized by a strong heterogeneity in their physical properties. The purpose of the study is the spatial variability of water transfers in a carbonated karstic aquifer. To this end, a high spatial density of information about the water transfer is needed. The characteristics of the site, a topographic hill of 13 km2 with eight boreholes, which was monitored hourly over four years, allows the study of the spatial variability of water transfers. The variability of the impulse response of the system is studied using autocorrelation and cross-correlation analysis between the rainfall and piezometric level time series. The shapes of the autocorrelation and cross-correlation functions vary according to the geographical location of the boreholes, that proves a spatial organization of the groundwater transfer. The response time varies depending on the thickness of the unsaturated zone by an unusual inverse correlation. In this case, the water level signal spatially integrates the signal transfer of the unsaturated zone and the signal transfer of the saturated part of the aquifer. Consequently, inertia and response time increased with the distance between the borehole and the top of piezometric dome. This description supports highly organized fast transfers in this karst aquifer and a highly connected fracture network.

  2. Dissolution on Titan and on Earth: Towards the age of Titan's karstic landscapes

    NASA Astrophysics Data System (ADS)

    Cornet, T.; Cordier, D.; Le Bahers, T.; Bourgeois, O.; Fleurant, C.; Le Mouélic, S.; Altobelli, N.

    2015-10-01

    The morphology of Titan's lacustrine depressions led to comparisons with terrestrial depressions developed by karstic dissolution. We tested this hypothesis by computing dissolution rates of Titan's solids in liquid methane. We inferred from these rates the timescales needed to create dissolution landforms of a given depth. Dissolution would be a very efficient geological process to shape Titan's surface, on timescales generally shorter than 100 Myrs, consistent with the youth of Titan's surface (<1 Gyr).

  3. Types of permeability development in limestone aquifers in Britain

    NASA Astrophysics Data System (ADS)

    Worthington, S. R. H.

    2009-04-01

    of karst aquifers types is well demonstrated by examples from England. The Chalk aquifer is an example of the microkarstic type. It has few caves but wells are characterised by high productivity, with a geometric mean transmissivity from pumping tests in 1257 wells of 440 m2/day, with a standard deviation of 0.76 log units. Well logs show that most production is from a few solutionally-enlarged fractures in each well. The Carboniferous Limestone aquifer provides a strong contrast. The geometric mean transmissivity from pumping tests in 59 wells is only 22 m2/day, with a standard deviation of 1.31 log units. Its wide range in well productivity and the presence of large cave streams are both indicators that it is a macrokarstic aquifer. These two contrasting aquifers share a number of common properties. Both have convergent flow to springs and channel networks with rapid flow (typically > 100 m/day). Furthermore, in both cases the matrix of the rock has relatively high porosity and low hydraulic conductivity, whereas the fractures and channels have low porosity and high hydraulic conductivity. Consequently, the flux of water through these aquifers occurs mainly through the channel networks although the matrix provides substantial storage. Other well-documented limestone aquifers in England such as the Magnesian Limestone and Jurassic limestones have transmissivity properties that are intermediate in value between the Chalk and the Carboniferous Limestone and have generally also been considered as being intermediate in karstic characteristics. The above conceptual model that karst aquifer type depends upon the size and frequency of channels provides a good explanation of the range of aquifer properties found in British limestone aquifers.

  4. Identification of Karstic Caves by Utilizing Two-Dimensional Electrical Resistivity Imaging (ERI) Method

    NASA Astrophysics Data System (ADS)

    Uçar, Fatih; Aktürk, Özgür

    2015-04-01

    The region consisting of easily soluble rocks is generally defined as karstic terrain and it is characterized by surface collapse and small or large scale dissolution voids on rock surface. Formation and expansion of these voids may cause dangerous situation during surface/subsurface construction works. Therefore, it is important to determine the location, size and dimension of karstic caves. Geophysical investigations are very helpful in determining the boundaries of geological subsurface structures. In order to determine subsurface profile and characteristic of soil, surface geophysical methods can be successfully applied. Electrical Resistivity Imaging (ERI) is the most important methods among the convenient and commonly used methods to determine subsurface profile. By using this method, cavernous and weathered zones can be determined easily. Within the scope of this study, near surface profiles were determined by utilizing ERI at Akdeniz University Campus and Masa Dağı region located in the city of Antalya, Turkey. The results obtained from four different locations in the Akdeniz University campus compared only with Vertical Electrical Sounding (VES) analyses. Since topographic cross-section is clearly seen in two different locations around Masa Dağı location, ERI results were superimposed with topography and also compared with VES. As a result, presences of subsurface cavities were determined and illustrated using 2D colorful images. Keywords: ERI, VES, Karstic terrain, Cave, Antalya

  5. Bitter taste receptors influence glucose homeostasis.

    PubMed

    Dotson, Cedrick D; Zhang, Lan; Xu, Hong; Shin, Yu-Kyong; Vigues, Stephan; Ott, Sandra H; Elson, Amanda E T; Choi, Hyun Jin; Shaw, Hillary; Egan, Josephine M; Mitchell, Braxton D; Li, Xiaodong; Steinle, Nanette I; Munger, Steven D

    2008-01-01

    TAS1R- and TAS2R-type taste receptors are expressed in the gustatory system, where they detect sweet- and bitter-tasting stimuli, respectively. These receptors are also expressed in subsets of cells within the mammalian gastrointestinal tract, where they mediate nutrient assimilation and endocrine responses. For example, sweeteners stimulate taste receptors on the surface of gut enteroendocrine L cells to elicit an increase in intracellular Ca(2+) and secretion of the incretin hormone glucagon-like peptide-1 (GLP-1), an important modulator of insulin biosynthesis and secretion. Because of the importance of taste receptors in the regulation of food intake and the alimentary responses to chemostimuli, we hypothesized that differences in taste receptor efficacy may impact glucose homeostasis. To address this issue, we initiated a candidate gene study within the Amish Family Diabetes Study and assessed the association of taste receptor variants with indicators of glucose dysregulation, including a diagnosis of type 2 diabetes mellitus and high levels of blood glucose and insulin during an oral glucose tolerance test. We report that a TAS2R haplotype is associated with altered glucose and insulin homeostasis. We also found that one SNP within this haplotype disrupts normal responses of a single receptor, TAS2R9, to its cognate ligands ofloxacin, procainamide and pirenzapine. Together, these findings suggest that a functionally compromised TAS2R receptor negatively impacts glucose homeostasis, providing an important link between alimentary chemosensation and metabolic disease. PMID:19092995

  6. Bitter Taste Receptor Polymorphisms and Human Aging

    PubMed Central

    Carrai, Maura; Crocco, Paolina; Montesanto, Alberto; Canzian, Federico; Rose, Giuseppina; Rizzato, Cosmeri

    2012-01-01

    Several studies have shown that genetic factors account for 25% of the variation in human life span. On the basis of published molecular, genetic and epidemiological data, we hypothesized that genetic polymorphisms of taste receptors, which modulate food preferences but are also expressed in a number of organs and regulate food absorption processing and metabolism, could modulate the aging process. Using a tagging approach, we investigated the possible associations between longevity and the common genetic variation at the three bitter taste receptor gene clusters on chromosomes 5, 7 and 12 in a population of 941 individuals ranging in age from 20 to 106 years from the South of Italy. We found that one polymorphism, rs978739, situated 212 bp upstream of the TAS2R16 gene, shows a statistically significant association (p = 0.001) with longevity. In particular, the frequency of A/A homozygotes increases gradually from 35% in subjects aged 20 to 70 up to 55% in centenarians. These data provide suggestive evidence on the possible correlation between human longevity and taste genetics. PMID:23133589

  7. Geochemical processes during five years of aquifer storage recovery.

    PubMed

    Herczeg, Andrew L; Rattray, Karen J; Dillon, Peter J; Pavelic, Paul; Barry, Karen E

    2004-01-01

    A key factor in the long-term viability of aquifer storage recovery (ASR) is the extent of mineral solution interaction between two dissimilar water types and consequent impact on water quality and aquifer stability. We collected geochemical and isotopic data from three observation wells located 25, 65, and 325 m from an injection well at an experimental ASR site located in a karstic, confined carbonate aquifer in South Australia. The experiment involved five major injection cycles of a total of 2.5 x 10(5) m3 of storm water (total dissolved solids [TDS] approximately 150 mg/L) into the brackish (TDS approximately 2400 mg/L) aquifer. Approximately 60% of the mixture was pumped out during the fifth year of the experiment. The major effect on water quality within a 25 m radius of the injection well following injection of storm water was carbonate dissolution (35 +/- 6 g of CaCO3 dissolved/m3 of aquifer) and sulfide mineral oxidation (50 +/- 10 g as FeS2/m3 after one injection). < 0.005% of the total aquifer carbonate matrix was dissolved during each injection event, and approximately 0.2% of the total reduced sulfur. Increasing amounts of ambient ground water was entrained into the injected mixture during each of the storage periods. High 14C(DIC) activities and slightly more negative delta13C(DIC) values measured immediately after injection events show that substantial CO2(aq) is produced by oxidation of organic matter associated with injectant. There were no detectable geochemical reactions while pumping during the recovery phase in the fifth year of the experiment. PMID:15161160

  8. Prunasin hydrolases during fruit development in sweet and bitter almonds.

    PubMed

    Sánchez-Pérez, Raquel; Belmonte, Fara Sáez; Borch, Jonas; Dicenta, Federico; Møller, Birger Lindberg; Jørgensen, Kirsten

    2012-04-01

    Amygdalin is a cyanogenic diglucoside and constitutes the bitter component in bitter almond (Prunus dulcis). Amygdalin concentration increases in the course of fruit formation. The monoglucoside prunasin is the precursor of amygdalin. Prunasin may be degraded to hydrogen cyanide, glucose, and benzaldehyde by the action of the β-glucosidase prunasin hydrolase (PH) and mandelonitirile lyase or be glucosylated to form amygdalin. The tissue and cellular localization of PHs was determined during fruit development in two sweet and two bitter almond cultivars using a specific antibody toward PHs. Confocal studies on sections of tegument, nucellus, endosperm, and embryo showed that the localization of the PH proteins is dependent on the stage of fruit development, shifting between apoplast and symplast in opposite patterns in sweet and bitter cultivars. Two different PH genes, Ph691 and Ph692, have been identified in a sweet and a bitter almond cultivar. Both cDNAs are 86% identical on the nucleotide level, and their encoded proteins are 79% identical to each other. In addition, Ph691 and Ph692 display 92% and 86% nucleotide identity to Ph1 from black cherry (Prunus serotina). Both proteins were predicted to contain an amino-terminal signal peptide, with the size of 26 amino acid residues for PH691 and 22 residues for PH692. The PH activity and the localization of the respective proteins in vivo differ between cultivars. This implies that there might be different concentrations of prunasin available in the seed for amygdalin synthesis and that these differences may determine whether the mature almond develops into bitter or sweet. PMID:22353576

  9. Geologic framework and hydrogeologic characteristics of the Edwards Aquifer outcrop, Hays County, Texas

    USGS Publications Warehouse

    Hanson, John A.; Small, Ted A.

    1995-01-01

    All of the hydrogeologic subdivisions within the Edwards aquifer outcrop in Hays County have some porosity and permeability. The most porous and permeable appear to be hydrogeologic subdivision VI, the Kirschberg evaporite member of the Kainer Formation; hydrogeologic subdivision III, the leached and collapsed members, undivided; and hydrogeologic subdivision II, the cyclic and marine members, undivided, of the Person Formation. The two types of porosity in the Edwards aquifer outcrop are fabric selective, which is related to depositional or diagenetic elements and typically exists in specific stratigraphic horizons; and not fabric selective, which can exist in any lithostratigraphic horizon. Permeability, the capacity of porous rock to transmit water, depends on the physical properties of the rock such as size, shape, and distribution of pores, and fissuring and dissolution. Two faults, San Marcos Springs and Mustang Branch, completely, or almost completely, offset the Edwards aquifer by juxtaposing Edwards aquifer limestone against nearly impermeable upper confining units along parts of their traces across Hays County. These faults are thought to be barriers, or partial barriers, to groundwater flow where the beds are juxtaposed. In Hays County, the Edwards aquifer probably is most vulnerable to surface contamination in the rapidly urbanizing areas on the Edwards aquifer outcrop. Contamination can result from spills or leakage of hazardous materials; or runoff on the intensely faulted and fractured, karstic limestone outcrops characteristic of the recharge zone.

  10. Microbial degradation of amygdalin of bitter apricot seeds (Prunus armeniaca).

    PubMed

    Nout, M J; Tunçel, G; Brimer, L

    1995-01-01

    Amygdalin is a cyanogenic glycoside occurring among others in almonds and bitter apricot seeds with interesting levels of dietary protein. Utilization of seeds for human or animal nutrition requires adequate detoxification. In the present paper, selected filamentous fungi (Mucor circinelloides, Penicillium nalgiovense) and yeasts (Hanseniaspora valbyensis, Endomyces fibuliger) were tested for their in-situ ability to decompose amygdalin. The latter (Endomyces fibuliger) was best able to grow on autoclaved bitter apricot seeds and detoxify them from 30 microMol CN/g dry matter to less than 1 microMol CN/g dry matter after 48 h of incubation at 27 degrees C.

  11. Anti-ulcer effect in rats of bitter cardamon constituents.

    PubMed

    Yamahara, J; Li, Y H; Tamai, Y

    1990-11-01

    The effects of bitter cardamon (the fruit of Alpinia oxphylla), used as a medicine and a condiment, on HCl/ethanol-induced gastric lesions in rats were examined. The acetone extract at 50 mg/kg, p.o. significantly inhibited gastric lesions by 57.0%. An analysis of the active constituents in the acetone extract was performed using column chromatography. Nootkatone at 20 mg/kg, p.o. significantly inhibited gastric lesion. These results suggest that nootkatone, the sesquiterpenoid is an important constituent in stomach medications containing bitter cardamon. PMID:2085887

  12. Sequence analysis of a bitter taste receptor gene repertoires in different ruminant species

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bitter taste has been extensively studied in mammalian species and is associated with sensitivity to toxins and with food choices that avoid dangerous substances in the diet. At the molecular level, bitter compounds are sensed by bitter taste receptor proteins (T2R) present at the surface of taste r...

  13. Using multiple chemical indicators to assess sources of nitrate and age of groundwater in a karstic spring basin

    USGS Publications Warehouse

    Katz, B.; Copeland, R.; Greenhalgh, T.; Ceryak, R.; Zwanka, W.

    2005-01-01

    Human health and ecological concerns have arisen due to a steady increase in nitrate-N concentrations during the past 40 years in Fannin Springs (0.3-4.7 mg/L), a regional discharge point with an average flow of >2.8 m3/second (>100 ft3/second) for water from the karstic Upper Floridan aquifer (UFA). Multiple chemical indicators (major dissolved species, 15N and 18O of nitrate, dissolved gases, 78 pesticides and degradates, and 67 organic compounds typically found in domestic and industrial wastewater) and transient tracers (3H/3He, chlorofluorocarbons [CFCs], sulfur hexafluoride [SF6]) were analyzed in water samples from nine wells along three transects and in spring water to assess groundwater age and potential contaminant sources. Land use is predominantly agricultural (52 percent) and forest (31 percent) in the 320 km2 (124 mi2) spring basin, which was delineated from a potentiometric-surface map of the UFA using high-resolution water-level data. Nitrate-N concentrations were highly variable in the oxic UFA and ranged from <0.02 to 4.7 mg/L. ?? 15N-NO3 values (3.4-9.9 per mil) indicated that nitrate contamination originated from inorganic sources (synthetic fertilizer) and organic sources (manure spreading or waste disposal). Higher nitrate concentrations and the younger age of spring water relative to water from upgradient wells indicate better communication with N sources at the surface. Apparent ages of groundwater correlated positively with well depth (P < 0.05) and were younger in water from wells nearer to the spring (<8 years) compared with other wells (10-50 years). Most transient tracer concentrations were consistent with binary mixing curves representing mixtures of water recharged during the past 10 years and older water (recharged before 1940). Young water mixing fractions ranged from 0.07 to 0.90. Trace levels of herbicides found in groundwater and spring water were indicative of applications for vegetative control in agricultural and other land

  14. Estimating nitrogen loading to ground water and assessing vulnerability to nitrate contamination in a large karstic springs Basin, Florida

    USGS Publications Warehouse

    Katz, B.G.; Sepulveda, A.A.; Verdi, R.J.

    2009-01-01

    A nitrogen (N) mass-balance budget was developed to assess the sources of N affecting increasing ground-water nitrate concentrations in the 960-km 2 karstic Ichetucknee Springs basin. This budget included direct measurements of N species in rainfall, ground water, and spring waters, along with estimates of N loading from fertilizers, septic tanks, animal wastes, and the land application of treated municipal wastewater and residual solids. Based on a range of N leaching estimates, N loads to ground water ranged from 262,000 to 1.3 million kg/year; and were similar to N export from the basin in spring waters (266,000 kg/year) when 80-90% N losses were assumed. Fertilizers applied to cropland, lawns, and pine stands contributed about 51% of the estimated total annual N load to ground water in the basin. Other sources contributed the following percentages of total N load to ground water: animal wastes, 27%; septic tanks, 12%; atmospheric deposition, 8%; and the land application of treated wastewater and biosolids, 2%. Due to below normal rainfall (97.3 cm) during the 12-month rainfall collection period, N inputs from rainfall likely were about 30% lower than estimates for normal annual rainfall (136 cm). Low N-isotope values for six spring waters (??15N-NO3 = 3.3 to 6.3???) and elevated potassium concentrations in ground water and spring waters were consistent with the large N contribution from fertilizers. Given ground-water residence times on the order of decades for spring waters, possible sinks for excess N inputs to the basin include N storage in the unsaturated zone and parts of the aquifer with relatively sluggish ground-water movement and denitrification. A geographical-based model of spatial loading from fertilizers indicated that areas most vulnerable to nitrate contamination were located in closed depressions containing sinkholes and other dissolution features in the southern half of the basin. ?? 2009 American Water Resources Association.

  15. Modeling suspended sediment transport and assessing the impacts of climate change in a karstic Mediterranean watershed.

    PubMed

    Nerantzaki, S D; Giannakis, G V; Efstathiou, D; Nikolaidis, N P; Sibetheros, I Α; Karatzas, G P; Zacharias, I

    2015-12-15

    Mediterranean semi-arid watersheds are characterized by a climate type with long periods of drought and infrequent but high-intensity rainfalls. These factors lead to the formation of temporary flow tributaries which present flashy hydrographs with response times ranging from minutes to hours and high erosion rates with significant sediment transport. Modeling of suspended sediment concentration in such watersheds is of utmost importance due to flash flood phenomena, during which, large quantities of sediments and pollutants are carried downstream. The aim of this study is to develop a modeling framework for suspended sediment transport in a karstic watershed and assess the impact of climate change on flow, soil erosion and sediment transport in a hydrologically complex and intensively managed Mediterranean watershed. The Soil and Water Assessment Tool (SWAT) model was coupled with a karstic flow and suspended sediment model in order to simulate the hydrology and sediment yield of the karstic springs and the whole watershed. Both daily flow data (2005-2014) and monthly sediment concentration data (2011-2014) were used for model calibration. The results showed good agreement between observed and modeled values for both flow and sediment concentration. Flash flood events account for 63-70% of the annual sediment export depending on a wet or dry year. Simulation results for a set of IPCC "A1B" climate change scenarios suggested that major decreases in surface flow (69.6%) and in the flow of the springs (76.5%) take place between the 2010-2049 and 2050-2090 time periods. An assessment of the future ecological flows revealed that the frequency of minimum flow events increases over the years. The trend of surface sediment export during these periods is also decreasing (54.5%) but the difference is not statistically significant due to the variability of the sediment. On the other hand, sediment originating from the springs is not affected significantly by climate change.

  16. Modeling suspended sediment transport and assessing the impacts of climate change in a karstic Mediterranean watershed.

    PubMed

    Nerantzaki, S D; Giannakis, G V; Efstathiou, D; Nikolaidis, N P; Sibetheros, I Α; Karatzas, G P; Zacharias, I

    2015-12-15

    Mediterranean semi-arid watersheds are characterized by a climate type with long periods of drought and infrequent but high-intensity rainfalls. These factors lead to the formation of temporary flow tributaries which present flashy hydrographs with response times ranging from minutes to hours and high erosion rates with significant sediment transport. Modeling of suspended sediment concentration in such watersheds is of utmost importance due to flash flood phenomena, during which, large quantities of sediments and pollutants are carried downstream. The aim of this study is to develop a modeling framework for suspended sediment transport in a karstic watershed and assess the impact of climate change on flow, soil erosion and sediment transport in a hydrologically complex and intensively managed Mediterranean watershed. The Soil and Water Assessment Tool (SWAT) model was coupled with a karstic flow and suspended sediment model in order to simulate the hydrology and sediment yield of the karstic springs and the whole watershed. Both daily flow data (2005-2014) and monthly sediment concentration data (2011-2014) were used for model calibration. The results showed good agreement between observed and modeled values for both flow and sediment concentration. Flash flood events account for 63-70% of the annual sediment export depending on a wet or dry year. Simulation results for a set of IPCC "A1B" climate change scenarios suggested that major decreases in surface flow (69.6%) and in the flow of the springs (76.5%) take place between the 2010-2049 and 2050-2090 time periods. An assessment of the future ecological flows revealed that the frequency of minimum flow events increases over the years. The trend of surface sediment export during these periods is also decreasing (54.5%) but the difference is not statistically significant due to the variability of the sediment. On the other hand, sediment originating from the springs is not affected significantly by climate change

  17. Bottle gourd (Lagenaria siceraria) toxicity: a "bitter" diagnostic dilemma.

    PubMed

    Khatib, Khalid Ismail; Borawake, Kapil Sharad

    2014-12-01

    Consumption of a glass of bottle gourd juice is thought to work as a health "tonic" and part of traditional healthy living practices in India. The juice may in certain circumstances turn bitter with increased levels of the cytotoxic compound called Cucurbitacins. If the bitter juice is consumed it causes a toxic reaction in the gut, leading to abdominal discomfort/pain, vomiting, hematemesis, and hypotension which may be rarely fatal, especially in persons with pre-existing illness. In the absence of clear cut history regarding the consumption of the bitter bottle gourd juice and the initiation of symptoms, the differential diagnosis for the above symptoms will include diseases causing gastrointestinal bleed with hypotension and/or shock. We report a case of bitter bottle gourd poisoning presenting with abdominal symptoms, hematemesis and shock and with an initial differential diagnosis of septicemia with septic shock and multi-organ involvement. We conduct a literature review and ponder the various differential diagnoses of this clinical scenario. PMID:25653981

  18. Healthy virgin olive oil: a matter of bitterness.

    PubMed

    Vitaglione, Paola; Savarese, Maria; Paduano, Antonello; Scalfi, Luca; Fogliano, Vincenzo; Sacchi, Raffaele

    2015-01-01

    Virgin olive oil (VOO) is the pillar fat of Mediterranean diet. It is made from olive fruits and obtained by squeezing olives without any solvent extraction. Respect to the seed oils, an unique polar polyphenol-rich fraction gives VOO a bitter and pungent taste. The recent substantiation by European Food Safety Authority (EFSA) of a health claim for VOO polyphenols may represent an efficient stimulus to get the maximum health benefit from one of the most valuable traditional product of Mediterranean countries educating consumers to the relationship between the VOO bitterness and its health effect. Agronomical practices and new processing technology to avoid phenolic oxidation and hydrolysis and to enhance the aromatic components of the VOO have been developed and they can be used to modulate taste and flavor to diversify the products on the market. VOOs having high concentration of phenol compounds are bitter and pungent therefore many people do not consume them, thus loosing the health benefits related to their intake. In this paper, the chemist's and nutritionist's point of view has been considered to address possible strategies to overcome the existing gap between the quality perceived by consumer and that established by expert tasters. Educational campaigns emphasizing the bitter-health link for olive oils should be developed.

  19. Studies and projections of hydraulic conductivity of Devonian Plavinu and Daugava carbonate aquifers in Latvia

    NASA Astrophysics Data System (ADS)

    Perkone, E.; Delina, A.; Saks, T.; Raga, B.; Jātnieks, J.; Klints, I.; Popovs, K.; Babre, A.; Bikše, J.; Kalvāns, A.; Retike, I.; Ukass, J.

    2012-04-01

    Carbonate aquifers show a very wide range of hydrogeological characteristics. Carbonate rock hydrogeology display two extremes: on one hand hydrogeological properties of the carbonates are governed by the pathways of the preferential groundwater flow typical in karstic regions, on the other - some carbonate aquifers behave almost like a homogeneous, isotropic, porous medium. Most lie between these extremes, but these case variations complicates the study of carbonate aquifer properties. In this study the results of the hydraulic conductivity in carbonate aquifers measurements, hydraulic conductivity correlation between sediments lithology and the aquifer surface depth and fractures research is presented. Upper Devonian Frasnian stage Pļaviņu and Daugava carbonate aquifers in the Latvian part of the Baltic basin is considered. The aim of this research is to elaborate characteristic hydraulic conductivity values for each aquifer based on existing data of the pumping test results and other aquifer properties. Pļaviņu and Daugava carbonate aquifers mainly consist of jointed dolomite with intermediate layers of dolomitic marlstone, limestone, clays and gypsum. These aquifers are prevalent in most of the study area, except Northern and South - Eastern parts of the territory. In geological structure Daugava aquifer lies above Pļaviņu aquifer. Daugava aquifer depth changes from 10 - 20 and even less meters in Eastern part to 250 - 300 m in South - West part of study area, but thickness varies from few meters to 30 m. Pļaviņu aquifer surface depth varies from 20 - 30 m, but in uplands surface depth reaches more than 120 m, in Eastern part to more than 300 m in South - West part of study area. Aquifer average thickness varies from 20 - 40 m, but in areas with buried valleys thickness can be less than 10 meters. Outcrops of these sediments are occurring in banks of largest rivers and in some areas aquifers are karstified. In studies of the carbonate aquifers it is

  20. Estimation of intrinsic aquifer vulnerability with index-overlay and statistical methods: the case of eastern Kopaida, central Greece

    NASA Astrophysics Data System (ADS)

    Tziritis, E.; Lombardo, L.

    2016-03-01

    The intrinsic vulnerability of a karstic aquifer system in central Greece was jointly assessed with the use of a statistical approach and PI method, as a function of topography, protective cover effectiveness and the degree to which this cover is bypassed due to flow conditions. The input data for the index-overlay PI method were derived from field works and 71 boreholes of the area; the information was obtained, subsequently its critical factors were compiled which included lithology, fissuring and karstification of bedrock, soil characteristics, hydrology, hydrogeology, topography and vegetation. The aforementioned parameters were processed jointly with the aid of a GIS and yielded the final estimation of intrinsic aquifer vulnerability to contamination. Results were compared with an equivalent spatially distributed probability map obtained through a stochastic approach. The calibration and test phase of the latter relied on morphometric conditions derived by terrain analyses of a digital elevation model as well as on geology and land use from thematic maps. This procedure allowed taking into account the topographic influences with respect to a deep system such as the local karstic aquifer of eastern Kopaida basin. Finally, results were validated with ground truth nitrate values obtained from 41 groundwater samples, highlighted the spatial delineation of susceptible areas to contamination in both cases and provided a robust tool for regional planning actions and water resources management schemes.

  1. Monitoring and modeling of water storage in karstic area (Larzac, France) with a continuous supraconducting gravimeter

    NASA Astrophysics Data System (ADS)

    Benjamin, Fores; Cédric, Champollion; Nicolas, Lemoigne; Jean, Chéry

    2014-05-01

    Quantitative knowledge of the groundwater storage and transfer in karstic area is crucial for water resources management and protection. As the karst hydro-geological properties are highly heterogeneous and scale dependent, geophysical observations such as time dependant gravity could be helpful to fill the gap between local (based on boreholes, moisture sensors, …) and global (based on chemistry, river flow, …) studies. Since more than 2 years, the iGrav #002 supraconducting gravimeter is continuously operating in the French GEK observatory(Géodésie de l'Environnement Karstique, OSU OREME, SNO H+) in the Larzac karstic plateau (south of France). The observatory is surrounding more than 250m karstified dolomite, with an unsaturated zone of ~150m thickness. First, the evaluation of the iGrav data (calibration, steps and drift) will be presented. Then a careful analysis of the global, topographic and building effects will be done to evaluate the local water storage only. The gravity data will be integrated with the water level data in nearby boreholes and petrophysical data from core samples. Finally, simple hydrological models will be presented to help the interpretation on the karst groundwater storage and transfer and to merge the whole dataset.

  2. Calcite Biomineralization by Bacterial Isolates from the Recently Discovered Pristine Karstic Herrenberg Cave

    PubMed Central

    Rusznyák, Anna; Akob, Denise M.; Nietzsche, Sándor; Eusterhues, Karin; Totsche, Kai Uwe; Neu, Thomas R.; Frosch, Torsten; Popp, Jürgen; Keiner, Robert; Geletneky, Jörn; Katzschmann, Lutz; Schulze, Ernst-Detlef

    2012-01-01

    Karstic caves represent one of the most important subterranean carbon storages on Earth and provide windows into the subsurface. The recent discovery of the Herrenberg Cave, Germany, gave us the opportunity to investigate the diversity and potential role of bacteria in carbonate mineral formation. Calcite was the only mineral observed by Raman spectroscopy to precipitate as stalactites from seepage water. Bacterial cells were found on the surface and interior of stalactites by confocal laser scanning microscopy. Proteobacteria dominated the microbial communities inhabiting stalactites, representing more than 70% of total 16S rRNA gene clones. Proteobacteria formed 22 to 34% of the detected communities in fluvial sediments, and a large fraction of these bacteria were also metabolically active. A total of 9 isolates, belonging to the genera Arthrobacter, Flavobacterium, Pseudomonas, Rhodococcus, Serratia, and Stenotrophomonas, grew on alkaline carbonate-precipitating medium. Two cultures with the most intense precipitate formation, Arthrobacter sulfonivorans and Rhodococcus globerulus, grew as aggregates, produced extracellular polymeric substances (EPS), and formed mixtures of calcite, vaterite, and monohydrocalcite. R. globerulus formed idiomorphous crystals with rhombohedral morphology, whereas A. sulfonivorans formed xenomorphous globular crystals, evidence for taxon-specific crystal morphologies. The results of this study highlighted the importance of combining various techniques in order to understand the geomicrobiology of karstic caves, but further studies are needed to determine whether the mineralogical biosignatures found in nutrient-rich media can also be found in oligotrophic caves. PMID:22179248

  3. Calcite biomineralization by bacterial isolates from the recently discovered pristine karstic herrenberg cave.

    PubMed

    Rusznyák, Anna; Akob, Denise M; Nietzsche, Sándor; Eusterhues, Karin; Totsche, Kai Uwe; Neu, Thomas R; Frosch, Torsten; Popp, Jürgen; Keiner, Robert; Geletneky, Jörn; Katzschmann, Lutz; Schulze, Ernst-Detlef; Küsel, Kirsten

    2012-02-01

    Karstic caves represent one of the most important subterranean carbon storages on Earth and provide windows into the subsurface. The recent discovery of the Herrenberg Cave, Germany, gave us the opportunity to investigate the diversity and potential role of bacteria in carbonate mineral formation. Calcite was the only mineral observed by Raman spectroscopy to precipitate as stalactites from seepage water. Bacterial cells were found on the surface and interior of stalactites by confocal laser scanning microscopy. Proteobacteria dominated the microbial communities inhabiting stalactites, representing more than 70% of total 16S rRNA gene clones. Proteobacteria formed 22 to 34% of the detected communities in fluvial sediments, and a large fraction of these bacteria were also metabolically active. A total of 9 isolates, belonging to the genera Arthrobacter, Flavobacterium, Pseudomonas, Rhodococcus, Serratia, and Stenotrophomonas, grew on alkaline carbonate-precipitating medium. Two cultures with the most intense precipitate formation, Arthrobacter sulfonivorans and Rhodococcus globerulus, grew as aggregates, produced extracellular polymeric substances (EPS), and formed mixtures of calcite, vaterite, and monohydrocalcite. R. globerulus formed idiomorphous crystals with rhombohedral morphology, whereas A. sulfonivorans formed xenomorphous globular crystals, evidence for taxon-specific crystal morphologies. The results of this study highlighted the importance of combining various techniques in order to understand the geomicrobiology of karstic caves, but further studies are needed to determine whether the mineralogical biosignatures found in nutrient-rich media can also be found in oligotrophic caves.

  4. Identification of anthropogenic and natural inputs of sulfate into a karstic coastal groundwater system in northeast China: evidence from major ions, δ13CDIC and δ34SSO4

    NASA Astrophysics Data System (ADS)

    Han, D.; Song, X.; Currell, M. J.

    2015-11-01

    The hydrogeochemical processes controlling groundwater evolution in the Daweijia area of Dalian, northeast China, were characterized using hydrochemistry and isotopes of carbon and sulfur (δ13CDIC and δ34SSO4). The aim was to distinguish anthropogenic impacts as distinct from natural processes, with a particular focus on sulfate, which is found at elevated levels (range: 54.4 to 368.8 mg L-1; mean: 174.4 mg L-1) in fresh and brackish groundwater. The current investigation reveals minor seawater intrusion impact (not exceeding 5 % of overall solute load), in contrast with extensive impacts observed in 1982 during the height of intensive abstraction. This indicates that measures to restrict groundwater abstraction have been effective. However, hydrochemical facies analysis shows that the groundwater remains in a state of ongoing hydrochemical evolution (towards Ca-Cl type water) and quality degradation (increasing nitrate and sulphate concentrations). The wide range of NO3 concentrations (74.7-579 mg L-1) in the Quaternary aquifer indicates considerable input of fertilizers and/or leakage from septic systems. Both δ13C (-14.5 to -5.9 ‰) and δ34SSO4 (+5.4-+13.1 ‰) values in groundwater show increasing trends along groundwater flow paths. While carbonate minerals may contribute to increasing δ13CDIC and δ34SSO4 values in deep karstic groundwater, high loads of agricultural fertilizers reaching the aquifer via irrigation return flow are likely the main source of the dissolved sulfate in Quaternary groundwater, as shown by distinctive isotopic ratios and a lack of evidence for other sources in the major ion chemistry. According to isotope mass balance calculations, the fertilizer contribution to overall sulfate has reached an average of 62.1 % in the Quaternary aquifer, which has a strong hydraulic connection to the underlying carbonate aquifer. The results point to an alarming level of impact from the local intensive agriculture on the groundwater system, a

  5. Sweet and bitter tastes of alcoholic beverages mediate alcohol intake in of-age undergraduates.

    PubMed

    Lanier, Sarah A; Hayes, John E; Duffy, Valerie B

    2005-01-17

    Alcoholic beverages are complex stimuli, giving rise to sensations that promote or inhibit intake. Previous research has shown associations between 6-n-propylthiouracil (PROP) bitterness, one marker of genetic variation in taste, and alcohol behaviors. We tested the PROP bitterness and alcohol intake relationship as mediated by tastes of sampled alcoholic beverages. Forty-nine undergraduates (mean age=22 years) participated. According to the Alcohol Use Disorders Identification Test (AUDIT), only 3 of 49 subjects reported patterns indicating problematic drinking. Participants used the general Labeled Magnitude Scale to rate PROP bitterness and tastes from and preference for Pilsner beer, blended scotch whiskey, instant espresso and unsweetened grapefruit juice. Alcohol intake was reported over a typical week. Regression analysis tested the hypothesis that PROP bitterness influenced alcohol bitterness and sweetness, which in turn predicted alcohol intake. Those who tasted less PROP bitterness tasted all beverages as less bitter and more preferred. Sweetness of scotch was significantly greater in those who tasted PROP as least bitter. For scotch, greater sweetness and less bitterness from sampled scotch were direct predictors of greater alcohol intake. For beer, preference ratings were better predictors of alcohol intake than the bitter or sweet tastes of the sampled beer. These findings support that PROP bitterness predicts both positive and negative tastes from alcoholic beverages and that those tastes may predict alcohol intake. The college environment may attenuate direct effects of PROP bitterness and intake. Here, PROP bitterness does not predict alcohol intake directly, but acts instead through sweet and bitter tastes of alcoholic beverages. PMID:15639168

  6. Hydrostratigraphic subdivisions and fault barriers of the Edwards aquifer, south-central Texas, U.S.A.

    USGS Publications Warehouse

    Maclay, R.W.; Small, T.A.

    1983-01-01

    The karstic Edwards Limestone within the Balcones Fault Zone of south-central Texas forms a productive confined aquifer that consists predominately of dense carbonate rocks and contains several layers of highly permeable and porous honeycombed rocks that have been produced by the leaching of evaporitic, tidal flat or reefal deposits. Fractures have hydraulically interconnected these layers at some places. Faults, however, commonly place rocks of very high-permeability opposite rocks of very low permeability, thus creating a lateral discontinuity and a flow barrier. At places, fault barriers probably cause partial to almost complete blockage of groundwater flow normal to the fault. ?? 1982.

  7. Genetic and Environmental Determinants of Bitter Perception and Sweet Preferences

    PubMed Central

    Mennella, Julie A.; Pepino, M. Yanina; Reed, Danielle R.

    2006-01-01

    Objective Flavor is the primary dimension by which young children determine food acceptance. However, children are not merely miniature adults because sensory systems mature postnatally and their responses to certain tastes differ markedly from adults. Among these differences are heightened preferences for sweet-tasting and greater rejection of bitter-tasting foods. The present study tests the hypothesis that genetic variations in the newly discovered TAS2R38 taste gene as well as cultural differences are associated with differences in sensitivity to the bitter taste of propylthiouracil (PROP) and preferences for sucrose and sweet-tasting foods and beverages in children and adults. Design Genomic DNA was extracted from cheek cells of a racially and ethnically diverse sample of 143 children and their mothers. Alleles of the gene TAS2R38 were genotyped. Participants were grouped by the first variant site, denoted A49P, because the allele predicts a change from the amino acid alanine (A) to proline (P) at position 49. Henceforth, individuals who were homozygous for the bitter-insensitive allele are referred to as AA, those who were heterozygous for the bitter-insensitive allele are referred to as AP, and those who were homozygous for the bitter-sensitive allele are referred to as PP. Using identical procedures for children and mothers, PROP sensitivity and sucrose preferences were assessed by using forced-choice procedures that were embedded in the context of games that minimized the impact of language development and were sensitive to the cognitive limitations of pediatric populations. Participants were also asked about their preferences in cereals and beverages, and mothers completed a standardized questionnaire that measured various dimensions of their children’s temperament. Results Genetic variation of the A49P allele influenced bitter perception in children and adults. However, the phenotype-genotype relationship was modified by age such that 64% of

  8. Masking Vegetable Bitterness to Improve Palatability Depends on Vegetable Type and Taste Phenotype

    PubMed Central

    2013-01-01

    Consumption of dark green vegetables falls short of recommendations, in part, because of unpleasant bitterness. A laboratory-based study of 37 adults was used to determine bitter and hedonic responses to vegetables (asparagus, Brussels sprouts, kale) with bitter masking agents (1.33 M sodium acetate, 10 and 32 mM sodium chloride, and 3.2 mM aspartame) and then characterized by taste phenotype and vegetable liking. In repeated-measures ANOVA, aspartame was most effective at suppressing bitterness and improving hedonic responses for all sampled vegetables. Among the sodium salts, 32 mM sodium chloride decreased bitterness for kale and sodium acetate reduced bitterness across all vegetables with a tendency to increase liking for Brussels sprouts, as release from mixture suppression increased perceived sweetness. Participants were nearly equally divided into three 6-n-propylthiouracil (PROP) phenotype groups. Those tasting the least PROP bitterness (non-tasters) reported least vegetable bitterness, and the additives produced little change in vegetable liking. Aspartame persisted as the most effective bitter blocker for the PROP tasters (medium, supertasters), improving vegetable liking for the medium tasters but too much sweetness for supertasters. The sodium salts showed some bitter blocking for PROP tasters, particularly sodium acetate, without significant gains in vegetable liking. Via a survey, adults characterized as low vegetable likers reported greater increase in vegetable liking with the maskers than did vegetable likers. These results suggest that bitter masking agents (mainly sweeteners) can suppress bitterness to increase acceptance if they are matched to perceived vegetable bitterness or to self-reported vegetable disliking. PMID:23682306

  9. Masking Vegetable Bitterness to Improve Palatability Depends on Vegetable Type and Taste Phenotype.

    PubMed

    Sharafi, Mastaneh; Hayes, John E; Duffy, Valerie B

    2013-03-01

    Consumption of dark green vegetables falls short of recommendations, in part, because of unpleasant bitterness. A laboratory-based study of 37 adults was used to determine bitter and hedonic responses to vegetables (asparagus, Brussels sprouts, kale) with bitter masking agents (1.33 M sodium acetate, 10 and 32 mM sodium chloride, and 3.2 mM aspartame) and then characterized by taste phenotype and vegetable liking. In repeated-measures ANOVA, aspartame was most effective at suppressing bitterness and improving hedonic responses for all sampled vegetables. Among the sodium salts, 32 mM sodium chloride decreased bitterness for kale and sodium acetate reduced bitterness across all vegetables with a tendency to increase liking for Brussels sprouts, as release from mixture suppression increased perceived sweetness. Participants were nearly equally divided into three 6-n-propylthiouracil (PROP) phenotype groups. Those tasting the least PROP bitterness (non-tasters) reported least vegetable bitterness, and the additives produced little change in vegetable liking. Aspartame persisted as the most effective bitter blocker for the PROP tasters (medium, supertasters), improving vegetable liking for the medium tasters but too much sweetness for supertasters. The sodium salts showed some bitter blocking for PROP tasters, particularly sodium acetate, without significant gains in vegetable liking. Via a survey, adults characterized as low vegetable likers reported greater increase in vegetable liking with the maskers than did vegetable likers. These results suggest that bitter masking agents (mainly sweeteners) can suppress bitterness to increase acceptance if they are matched to perceived vegetable bitterness or to self-reported vegetable disliking.

  10. Bitterness evaluation of acidic pharmaceutical substances (NSAIDs) using a taste sensor.

    PubMed

    Yoshida, Miyako; Haraguchi, Tamami; Uchida, Takahiro

    2014-01-01

    The objective of this study was to evaluate an improved bitterness sensor which has been developed to allow the precise and sensitive prediction of the bitterness of acidic bitter pharmaceutical active ingredients, using as examples nine non-steroidal anti-inflammatory drugs (NSAIDs). The bitterness of the nine NSAIDs was measured using a multichannel taste-sensing system incorporating a bitterness sensor, C00, which has a membrane surface with high hydrophobicity, and was developed to allow an enhanced hydrophobic interaction with acidic bitter substances. The sourness intensities of the nine NSAIDs were also determined in gustatory sensation testing and by a taste sensor using a sourness-sensitive membrane, CA0. The 'Change in membrane Potential caused by Adsorption' (CPA) of sodium diclofenac and etodolac were also determined in the presence of increasing concentrations of tartaric acid using membrane C00. Multiple regression analysis performed on the data on bitterness intensity obtained using the taste sensor and in gustatory sensation testing showed that CPA values from C00 could be used to predict the bitterness of the NSAIDs. The derived equation was y = -0.0413 × CPA + 0.3164, where y represents the predicted bitterness intensity. There were concentration-dependent changes in the bitterness intensities of diclofenac sodium and etodolac without any change in their sourness intensities. For diclofenac sodium and etodolac, there was a good correlation between predicted and actual bitterness intensities in the presence of increasing concentrations of tartaric acid. The taste sensor may be useful for predicting the bitterness intensity of acidic bitter pharmaceutical active ingredients such as NSAIDs. PMID:25450633

  11. Allelic Variation in TAS2R Bitter Receptor Genes Associates with Variation in Sensations from and Ingestive Behaviors toward Common Bitter Beverages in Adults

    PubMed Central

    Hayes, John E.; Wallace, Margaret R.; Knopik, Valerie S.; Herbstman, Deborah M.; Bartoshuk, Linda M.

    2011-01-01

    The 25 human bitter receptors and their respective genes (TAS2Rs) contain unusually high levels of allelic variation, which may influence response to bitter compounds in the food supply. Phenotypes based on the perceived bitterness of single bitter compounds were first linked to food preference over 50 years ago. The most studied phenotype is propylthiouracil bitterness, which is mediated primarily by the TAS2R38 gene and possibly others. In a laboratory-based study, we tested for associations between TAS2R variants and sensations, liking, or intake of bitter beverages among healthy adults who were primarily of European ancestry. A haploblock across TAS2R3, TAS2R4, and TAS2R5 explained some variability in the bitterness of espresso coffee. For grapefruit juice, variation at a TAS2R19 single nucleotide polymorphism (SNP) was associated with increased bitterness and decreased liking. An association between a TAS2R16 SNP and alcohol intake was identified, and the putative TAS2R38–alcohol relationship was confirmed, although these polymorphisms did not explain sensory or hedonic responses to sampled scotch whisky. In summary, TAS2R polymorphisms appear to influence the sensations, liking, or intake of common and nutritionally significant beverages. Studying perceptual and behavioral differences in vivo using real foods and beverages may potentially identify polymorphisms related to dietary behavior even in the absence of known ligands. PMID:21163912

  12. Small karstic Dobra River (Croatia) suggested as natural laboratory for impactite research

    NASA Astrophysics Data System (ADS)

    Frančišković-Bilinski, Stanislav; Bilinski, Halka; Sikder, Arif M.

    2016-04-01

    An unexpected anomaly of magnetic susceptibility (MS) was observed in stream sediments of the upper course of the karstic Dobra River (Croatia). Preliminary results pointed to a possible impactite, formed by a shock event caused by a meteorite impact or by volcanic processes [1]. In addition to geophysical experiments, petrological and geochemical studies are reported [2, 3]. The multidisciplinary work for identification and confirmation of impact structure is still in progress. Results will be presented and the difficulties due to weathering and transport processes will be discussed and compared with recent literature [4, 5]. In reported results numerous evidences exist, which are in support of impact origin, such as vesicular glass with quench texture, ballen textures in the lechatelierite, presence of Troilite, etc. We suggest that the Dobra River from its source to the abyss in Ogulin (Upper Dobra) is a possible natural laboratory for studying processes of mixing between impactite material and fluvial sediments within a small area, including spherules exposed to water and in the overbank sediments. Especially the introduction of isotope studies in this research and enlargement of multinational team of experts are suggested. Literature: [1] Franči\\vsković-Bilinski, S., Bilinski, H., Scholger, R., Tomašić, N., Maldini, K. (2014): Magnetic spherules in sediments of the sinking karstic Dobra River (Croatia). Journal of soils and sediments 14(3), 600-614. [2] Franči\\vsković-Bilinski, S., Sikder, A.M., Bilinski, H., Castano, C.E., Garman, G.C. (2015): Traces of meteorite impact in the sediments of karstic Dobra River (Croatia). 15th International multidisciplinary scientific geoconference SGEM 2015 Conference proceedings, Vol. 1, 507-514. [3] Sikder, A.M., Franči\\vsković-Bilinski, S., Bilinski, H., Castano, C.E., Clifford, D.M., Turner, J.B., Garman, G.C. (2015): Petrographic analysis of the magnetic spherules from the sediments of karastic Dobra River

  13. Rebaudioside A and Rebaudioside D bitterness do not covary with Acesulfame K bitterness or polymorphisms in TAS2R9 and TAS2R31

    PubMed Central

    Allen, Alissa L.; McGeary, John E.; Hayes, John E.

    2013-01-01

    In order to reduce calories in foods and beverages, the food industry routinely uses non-nutritive sweeteners. Unfortunately, many are synthetically derived, and many consumers have a strong preference for natural sweeteners, irrespective of the safety data on synthetic non-nutritive sweeteners. Additionally, many non-nutritive sweeteners elicit aversive side tastes such as bitter and metallic in addition to sweetness. Bitterness thresholds of acesulfame-K (AceK) and saccharin are known to vary across bitter taste receptors polymorphisms in TAS2R31. RebA has shown to activate hTAS2R4 and hTAS2R14 in vitro. Here we examined bitterness and sweetness perception of natural and synthetic non-nutritive sweeteners. In a follow-up to a previous gene-association study, participants (n=122) who had been genotyped previously rated sweet, bitter and metallic sensations from rebaudioside A (RebA), rebaudioside D (RebD), aspartame, sucrose and gentiobiose in duplicate in a single session. For comparison, we also present sweet and bitter ratings of AceK collected in the original experiment for the same participants. At similar sweetness levels, aspartame elicited less bitterness than RebD, which was significantly less bitter than RebA. The bitterness of RebA and RebD showed wide variability across individuals, and bitterness ratings for these compounds were correlated. However, RebA and RebD bitterness did not covary with AceK bitterness. Likewise, single nucleotide polymorphisms (SNPs) shown previously to explain variation in the suprathreshold bitterness of AceK (rs3741845 in TAS2R9 and rs10772423 in TAS2R31) did not explain variation in RebA and RebD bitterness. Because RebA activates hT2R4 and hT2R14, a SNP in TAS2R4 previously associated with variation in bitterness perception was included here; there are no known functional SNPs for TAS2R14. In present data, a putatively functional SNP (rs2234001) in TAS2R4 did not explain variation in RebA or RebD bitterness. Collectively

  14. Long-Chain Fatty Acids Elicit a Bitterness-Masking Effect on Quinine and Other Nitrogenous Bitter Substances by Formation of Insoluble Binary Complexes.

    PubMed

    Ogi, Kayako; Yamashita, Haruyuki; Terada, Tohru; Homma, Ryousuke; Shimizu-Ibuka, Akiko; Yoshimura, Etsuro; Ishimaru, Yoshiro; Abe, Keiko; Asakura, Tomiko

    2015-09-30

    We have previously found that fatty acids can mask the bitterness of certain nitrogenous substances through direct molecular interactions. Using isothermal titration calorimetry, we investigated the interactions between sodium oleate and 22 bitter substances. The hydrochloride salts of quinine, promethazine, and propranolol interacted strongly with fatty acids containing 12 or more carbon atoms. The (1)H NMR spectra of these substances, obtained in the presence of the sodium salts of the fatty acids in dimethyl sulfoxide, revealed the formation of hydrogen bonds between the nitrogen atoms of the bitter substances and the carboxyl groups of the fatty acids. When sodium laurate and the hydrochloride salt of quinine were mixed in water, an equimolar complex formed as insoluble heterogeneous needlelike crystals. These results suggested that fatty acids interact directly with bitter substances through hydrogen bonds and hydrophobic interactions to form insoluble binary complexes that mask bitterness.

  15. Rebaudioside A and Rebaudioside D bitterness do not covary with Acesulfame K bitterness or polymorphisms in TAS2R9 and TAS2R31.

    PubMed

    Allen, Alissa L; McGeary, John E; Hayes, John E

    2013-09-01

    In order to reduce calories in foods and beverages, the food industry routinely uses non-nutritive sweeteners. Unfortunately, many are synthetically derived, and many consumers have a strong preference for natural sweeteners, irrespective of the safety data on synthetic non-nutritive sweeteners. Additionally, many non-nutritive sweeteners elicit aversive side tastes such as bitter and metallic in addition to sweetness. Bitterness thresholds of acesulfame-K (AceK) and saccharin are known to vary across bitter taste receptors polymorphisms in TAS2R31. RebA has shown to activate hTAS2R4 and hTAS2R14 in vitro. Here we examined bitterness and sweetness perception of natural and synthetic non-nutritive sweeteners. In a follow-up to a previous gene-association study, participants (n=122) who had been genotyped previously rated sweet, bitter and metallic sensations from rebaudioside A (RebA), rebaudioside D (RebD), aspartame, sucrose and gentiobiose in duplicate in a single session. For comparison, we also present sweet and bitter ratings of AceK collected in the original experiment for the same participants. At similar sweetness levels, aspartame elicited less bitterness than RebD, which was significantly less bitter than RebA. The bitterness of RebA and RebD showed wide variability across individuals, and bitterness ratings for these compounds were correlated. However, RebA and RebD bitterness did not covary with AceK bitterness. Likewise, single nucleotide polymorphisms (SNPs) shown previously to explain variation in the suprathreshold bitterness of AceK (rs3741845 in TAS2R9 and rs10772423 in TAS2R31) did not explain variation in RebA and RebD bitterness. Because RebA activates hT2R4 and hT2R14, a SNP in TAS2R4 previously associated with variation in bitterness perception was included here; there are no known functional SNPs for TAS2R14. In present data, a putatively functional SNP (rs2234001) in TAS2R4 did not explain variation in RebA or RebD bitterness. Collectively

  16. Long-Chain Fatty Acids Elicit a Bitterness-Masking Effect on Quinine and Other Nitrogenous Bitter Substances by Formation of Insoluble Binary Complexes.

    PubMed

    Ogi, Kayako; Yamashita, Haruyuki; Terada, Tohru; Homma, Ryousuke; Shimizu-Ibuka, Akiko; Yoshimura, Etsuro; Ishimaru, Yoshiro; Abe, Keiko; Asakura, Tomiko

    2015-09-30

    We have previously found that fatty acids can mask the bitterness of certain nitrogenous substances through direct molecular interactions. Using isothermal titration calorimetry, we investigated the interactions between sodium oleate and 22 bitter substances. The hydrochloride salts of quinine, promethazine, and propranolol interacted strongly with fatty acids containing 12 or more carbon atoms. The (1)H NMR spectra of these substances, obtained in the presence of the sodium salts of the fatty acids in dimethyl sulfoxide, revealed the formation of hydrogen bonds between the nitrogen atoms of the bitter substances and the carboxyl groups of the fatty acids. When sodium laurate and the hydrochloride salt of quinine were mixed in water, an equimolar complex formed as insoluble heterogeneous needlelike crystals. These results suggested that fatty acids interact directly with bitter substances through hydrogen bonds and hydrophobic interactions to form insoluble binary complexes that mask bitterness. PMID:26365517

  17. A triterpenoid from wild bitter gourd inhibits breast cancer cells

    NASA Astrophysics Data System (ADS)

    Bai, Li-Yuan; Chiu, Chang-Fang; Chu, Po-Chen; Lin, Wei-Yu; Chiu, Shih-Jiuan; Weng, Jing-Ru

    2016-03-01

    The antitumor activity of 3β,7β,25-trihydroxycucurbita-5,23(E)-dien-19-al (TCD), a triterpenoid isolated from wild bitter gourd, in breast cancer cells was investigated. TCD suppressed the proliferation of MCF-7 and MDA-MB-231 breast cancer cells with IC50 values at 72 h of 19 and 23 μM, respectively, via a PPARγ-independent manner. TCD induced cell apoptosis accompanied with pleiotrophic biological modulations including down-regulation of Akt-NF-κB signaling, up-regulation of p38 mitogen-activated protein kinase and p53, increased reactive oxygen species generation, inhibition of histone deacetylases protein expression, and cytoprotective autophagy. Together, these findings provided the translational value of TCD and wild bitter gourd as an antitumor agent for patients with breast cancer.

  18. A triterpenoid from wild bitter gourd inhibits breast cancer cells

    PubMed Central

    Bai, Li-Yuan; Chiu, Chang-Fang; Chu, Po-Chen; Lin, Wei-Yu; Chiu, Shih-Jiuan; Weng, Jing-Ru

    2016-01-01

    The antitumor activity of 3β,7β,25-trihydroxycucurbita-5,23(E)-dien-19-al (TCD), a triterpenoid isolated from wild bitter gourd, in breast cancer cells was investigated. TCD suppressed the proliferation of MCF-7 and MDA-MB-231 breast cancer cells with IC50 values at 72 h of 19 and 23 μM, respectively, via a PPARγ−independent manner. TCD induced cell apoptosis accompanied with pleiotrophic biological modulations including down-regulation of Akt-NF-κB signaling, up-regulation of p38 mitogen-activated protein kinase and p53, increased reactive oxygen species generation, inhibition of histone deacetylases protein expression, and cytoprotective autophagy. Together, these findings provided the translational value of TCD and wild bitter gourd as an antitumor agent for patients with breast cancer. PMID:26926586

  19. A triterpenoid from wild bitter gourd inhibits breast cancer cells.

    PubMed

    Bai, Li-Yuan; Chiu, Chang-Fang; Chu, Po-Chen; Lin, Wei-Yu; Chiu, Shih-Jiuan; Weng, Jing-Ru

    2016-01-01

    The antitumor activity of 3β,7β,25-trihydroxycucurbita-5,23(E)-dien-19-al (TCD), a triterpenoid isolated from wild bitter gourd, in breast cancer cells was investigated. TCD suppressed the proliferation of MCF-7 and MDA-MB-231 breast cancer cells with IC50 values at 72 h of 19 and 23 μM, respectively, via a PPARγ-independent manner. TCD induced cell apoptosis accompanied with pleiotrophic biological modulations including down-regulation of Akt-NF-κB signaling, up-regulation of p38 mitogen-activated protein kinase and p53, increased reactive oxygen species generation, inhibition of histone deacetylases protein expression, and cytoprotective autophagy. Together, these findings provided the translational value of TCD and wild bitter gourd as an antitumor agent for patients with breast cancer. PMID:26926586

  20. A triterpenoid from wild bitter gourd inhibits breast cancer cells

    NASA Astrophysics Data System (ADS)

    Bai, Li-Yuan; Chiu, Chang-Fang; Chu, Po-Chen; Lin, Wei-Yu; Chiu, Shih-Jiuan; Weng, Jing-Ru

    2016-03-01

    The antitumor activity of 3β,7β,25-trihydroxycucurbita-5,23(E)-dien-19-al (TCD), a triterpenoid isolated from wild bitter gourd, in breast cancer cells was investigated. TCD suppressed the proliferation of MCF-7 and MDA-MB-231 breast cancer cells with IC50 values at 72 h of 19 and 23 μM, respectively, via a PPARγ‑independent manner. TCD induced cell apoptosis accompanied with pleiotrophic biological modulations including down-regulation of Akt-NF-κB signaling, up-regulation of p38 mitogen-activated protein kinase and p53, increased reactive oxygen species generation, inhibition of histone deacetylases protein expression, and cytoprotective autophagy. Together, these findings provided the translational value of TCD and wild bitter gourd as an antitumor agent for patients with breast cancer.

  1. Oligomerization of TAS2R bitter taste receptors.

    PubMed

    Kuhn, Christina; Bufe, Bernd; Batram, Claudia; Meyerhof, Wolfgang

    2010-06-01

    A family of 25 G protein-coupled receptors, TAS2Rs, mediates bitter taste in humans. Many of the members of this family are coexpressed in a subpopulation of taste receptor cells on the tongue, thereby allowing the possibility of receptor-receptor interactions with potential influences on their function. In this study, we used several experimental approaches to investigate whether TAS2Rs can form oligomers and if this has an effect on receptor function. Coimmunoprecipitations clearly demonstrated that TAS2Rs can physically interact in HEK293T cells. Further bioluminescence resonance energy transfer analysis of all 325 possible binary combinations of TAS2Rs established that the vast majority of TAS2R pairs form oligomers, both homomers and heteromers. Subsequent screenings of coexpressed bitter receptors with 104 different tastants did not reveal any heteromer-specific agonists. Additional studies also showed no obvious influence of TAS2R hetero-oligomerization on plasma membrane localization or pharmacological properties of the receptors. Thus, our results show that receptor oligomerization occurs between TAS2R bitter taste receptors; however, functional consequences of hetero-oligomerization were not obvious.

  2. Bitter taste receptors: Novel insights into the biochemistry and pharmacology.

    PubMed

    Jaggupilli, Appalaraju; Howard, Ryan; Upadhyaya, Jasbir D; Bhullar, Rajinder P; Chelikani, Prashen

    2016-08-01

    Bitter taste receptors (T2Rs) belong to the super family of G protein-coupled receptors (GPCRs). There are 25 T2Rs expressed in humans, and these interact with a large and diverse group of bitter ligands. T2Rs are expressed in many extra-oral tissues and can perform diverse physiological roles. Structure-function studies led to the identification of similarities and dissimilarities between T2Rs and Class A GPCRs including amino acid conservation and novel motifs. However, the efficacy of most of the T2R ligands is not yet elucidated and the biochemical pharmacology of T2Rs is poorly understood. Recent studies on T2Rs characterized novel ligands including blockers for these receptors that include inverse agonist and antagonists. In this review we discuss the techniques used for elucidating bitter blockers, concept of ligand bias, generic amino acid numbering, the role of cholesterol, and conserved water molecules in the biochemistry and pharmacology of T2Rs. PMID:26995065

  3. Groundwater quality impacts from the land application of treated municipal wastewater in a large karstic spring basin: Chemical and microbiological indicators

    USGS Publications Warehouse

    Katz, B.G.; Griffin, Dale W.; Davis, J.H.

    2009-01-01

    Geochemical and microbiological techniques were used to assess water-quality impacts from the land application of treated municipal wastewater in the karstic Wakulla Springs basin in northern Florida. Nitrate-N concentrations have increased from about 0.2 to as high as 1.1??mg/L (milligrams per liter) during the past 30??years in Wakulla Springs, a regional discharge point for groundwater (mean flow about 11.3??m3/s) from the Upper Floridan aquifer (UFA). A major source of nitrate to the UFA is the approximately 64??million L/d (liters per day) of treated municipal wastewater applied at a 774??ha (hectare) sprayfield farming operation. About 260 chemical and microbiological indicators were analyzed in water samples from the sprayfield effluent reservoir, wells upgradient from the sprayfield, and from 21 downgradient wells and springs to assess the movement of contaminants into the UFA. Concentrations of nitrate-N, boron, chloride, were elevated in water samples from the sprayfield effluent reservoir and in monitoring wells at the sprayfield boundary. Mixing of sprayfield effluent water was indicated by a systematic decrease in concentrations of these constituents with distance downgradient from the sprayfield, with about a 10-fold dilution at Wakulla Springs, about 15??km (kilometers) downgradient from the sprayfield. Groundwater with elevated chloride and boron concentrations in wells downgradient from the sprayfield and in Wakulla Springs had similar nitrate isotopic signatures, whereas the nitrate isotopic composition of water from other sites was consistent with inorganic fertilizers or denitrification. The sprayfield operation was highly effective in removing most studied organic wastewater and pharmaceutical compounds and microbial indicators. Carbamazepine (an anti-convulsant drug) was the only pharmaceutical compound detected in groundwater from two sprayfield monitoring wells (1-2??ppt). One other detection of carbamazepine was found in a distant well

  4. Groundwater quality impacts from the land application of treated municipal wastewater in a large karstic spring basin: chemical and microbiological indicators.

    PubMed

    Katz, Brian G; Griffin, Dale W; Davis, J Hal

    2009-04-01

    Geochemical and microbiological techniques were used to assess water-quality impacts from the land application of treated municipal wastewater in the karstic Wakulla Springs basin in northern Florida. Nitrate-N concentrations have increased from about 0.2 to as high as 1.1 mg/L (milligrams per liter) during the past 30 years in Wakulla Springs, a regional discharge point for groundwater (mean flow about 11.3 m(3)/s) from the Upper Floridan aquifer (UFA). A major source of nitrate to the UFA is the approximately 64 million L/d (liters per day) of treated municipal wastewater applied at a 774 ha (hectare) sprayfield farming operation. About 260 chemical and microbiological indicators were analyzed in water samples from the sprayfield effluent reservoir, wells upgradient from the sprayfield, and from 21 downgradient wells and springs to assess the movement of contaminants into the UFA. Concentrations of nitrate-N, boron, chloride, were elevated in water samples from the sprayfield effluent reservoir and in monitoring wells at the sprayfield boundary. Mixing of sprayfield effluent water was indicated by a systematic decrease in concentrations of these constituents with distance downgradient from the sprayfield, with about a 10-fold dilution at Wakulla Springs, about 15 km (kilometers) downgradient from the sprayfield. Groundwater with elevated chloride and boron concentrations in wells downgradient from the sprayfield and in Wakulla Springs had similar nitrate isotopic signatures, whereas the nitrate isotopic composition of water from other sites was consistent with inorganic fertilizers or denitrification. The sprayfield operation was highly effective in removing most studied organic wastewater and pharmaceutical compounds and microbial indicators. Carbamazepine (an anti-convulsant drug) was the only pharmaceutical compound detected in groundwater from two sprayfield monitoring wells (1-2 ppt). One other detection of carbamazepine was found in a distant well water

  5. Later Middle Pleistocene human remains from the Almonda Karstic system, Torres Novas, Portugal.

    PubMed

    Trinkaus, Erik; Marks, Anthony E; Brugal, Jean Philip; Bailey, Shara E; Rink, W Jack; Richter, Daniel

    2003-09-01

    Later Middle Pleistocene archeological deposits of the Galeria Pesada (Gruta da Aroeira), Almonda Karstic System, Torres Novas, Portugal, yielded two archaic human teeth, a mandibular canine and a maxillary third molar. The C(1)presents moderate and asymmetrical shoveling with a stout root. The slightly worn M(3)exhibits at least four cusps with a large hypocone, three roots with large radicular plates, and an absence of taurodontism. They are moderately large for later Middle Pleistocene humans in their buccolingual crown diameters, although the M(3)mesiodistal diameter is modest. The C(1)exhibits labial calculus and multiple linear hypoplastic defects, but the M(3)is lesion free. Both teeth are morphologically similar to those of other Middle Pleistocene European humans and reinforce a pattern of dental hypertrophy among these archaic Homo.

  6. Physical Approaches to Masking Bitter Taste: Lessons from Food and Pharmaceuticals

    PubMed Central

    Hayes, John E.

    2016-01-01

    Many drugs and desirable phytochemicals are bitter, and bitter tastes are aversive. Food and pharmaceutical manufacturers share a common need for bitterness-masking strategies that allow them to deliver useful quantities of the active compounds in an acceptable form and in this review we compare and contrast the challenges and approaches by researchers in both fields. We focus on physical approaches, i.e., micro- or nano-structures to bind bitter compounds in the mouth, yet break down to allow release after they are swallowed. In all of these methods, the assumption is the degree of bitterness suppression depends on the concentration of bitterant in the saliva and hence the proportion that is bound. Surprisingly, this hypothesis has only rarely been fully tested using a combination of adequate human sensory trials and measurements of binding. This is especially true in pharmaceutical systems, perhaps due to the greater experimental challenges in sensory analysis of drugs. PMID:25205460

  7. Geochemistry and Hydrogeology of Water-Filled Sinkholes at Bitter Lake NWR, Roswell, NM

    NASA Astrophysics Data System (ADS)

    Premo, Z. E.; Crossey, L. J.

    2008-12-01

    Bitter Lake NWR in southeast (Roswell) New Mexico is located at the convergence of the Pecos River and the surface discharge region in the Roswell Artesian Basin (shallow alluvial aquifer and carbonate aquifer). The Refuge hosts approximately 50 water-filled sinkholes, which each support a unique and diverse aquatic ecosystem. An initial survey of water chemistries indicates that each sink has a unique chemical identity and neutral to alkaline pH. Sinkholes are filled by one or more artesian springs, groundwater seepage and possible hydrothermal water sources. We present results of water and gas analyses of 10 representative sinkholes, sampled during spring and summer, 2008. Analytical results, including major ions, metals (arsenic, selenium, iron), and gas chemistries are compared with monitoring well data from wells found to the north of the Refuge, along the Pecos River, and to the west, along the Pecos Slope - the regional aquifer recharge area. Well samples representative of regional groundwater provide potential end member perspectives for sources of sinkhole waters. Samples were collected incrementally from the surface to sinkhole floor to profile the limnological structure and to assess chemical variation and mixing through the water column. A sonde was deployed to measure and record physical parameters. Results of the analysis are used to describe the geochemical mixing that is occurring within the sinks. As each sink behaves as an independent unit, those separated by less than 10 meters can have dramatic variability in chemical signature and biological influence. For example, among the 29 sinks sampled during the initital survey, chloride concentrations range from 1.912x10-3 to 1.405 mol/kg; sulfate from 7.204x10-4 to 0.1364 mol/kg; and fluoride from 3.579x10-4 to 3.453x10-3 mol/kg. Along the Pecos Slope, groundwater chloride concentrations increase from less than 1.410x10-3 mol/kg near the major recharge area in the Sacramento Mountains to 0.141 mol

  8. Dissolution on Titan and on Earth: Towards the Age of Titan's Karstic-like Landscapes

    NASA Astrophysics Data System (ADS)

    Cornet, T.; Cordier, D.; Le Bahers, T.; Bourgeois, O.; Fleurant, C.; Le Mouelic, S.; Altobelli, N.

    2015-12-01

    Titan's polar surface is dotted with hundreds of lacustrine depressions. Their morphology suggests that their development would be associated to karstic-like processes, involving Titan's liquids (methane, ethane) dissolving the solid surface, presumably composed of organics and ices. In the present work, we test whether or not surface dissolution could be a major landshaping process on Titan using a solutional denudation rates model. The model is based on thermodynamics (solute solubility in solvents) and climatic (temperature, precipitation rates) parameters and has already been used to describe the dissolution of carbonates in karstic areas on Earth. It allows inference of rough formation timescales for topographic depressions of a given depth, developed by chemical erosion only. We computed and compared the denudation rates of pure solid organics in liquid hydrocarbons and of minerals in liquid water over Titan and Earth timescales. We then investigated the denudation rates of superficial organic layers in liquid methane over one Titan year. At this timescale, such a layer on Titan would behave like salts or carbonates on Earth depending on its composition, which means that dissolution processes would likely occur but would be 30 times slower on Titan compared to the Earth due to the seasonality of methane precipitation. Assuming that Titan's past climatic conditions remained close to the present ones, and assuming an average depth of 100 m for Titan's lacustrine depressions, these could have developed in a few tens of millions of years at polar latitudes higher than 70°N and S, and a few hundreds of million years at lower polar latitudes. The ages determined are consistent with the youth of the surface (<1 Gyr) and the repartition of dissolution-related landforms on Titan.

  9. Investigation of freshwater sponges spicules deposits in a karstic lake in Brazil.

    PubMed

    Machado, V S; Volkmer-Ribeiro, C; Iannuzzi, R

    2016-02-01

    The environmental conditions which contributed to the formation of the notorious quaternary deposits of freshwater sponge spicules in karstic lentic environments in Brazil have been subject of some speculation. No investigation has yet been conducted to test whether these deposits currently originate in karstic lakes. To provide for such an investigation, Serra Negra Lake, which is formed on an ultramafic-alkaline-carbonatite dome at central western Brazil, close to the area of occurrence of the paleo-deposits was selected for the study. Bottom sediments were sampled at 10 stations across the lake, and water was sampled at five of the stations, in June/2011 (rainy season) and October/2011 (dry season). Analysis of granulometry, organic matter and presence of spicules were carried out in the sediments. Lake water was analysed for the main physical and chemical characteristics. Deposit of spicules was restricted to the northern area of the lake, which is rich in macrophyte. The taxonomic analysis of the spicules indicated the contribution of five sponge species, Dosilia pydanieli, Metania spinata, Radiospongilla amazonensis, Trochospongilla variabilis and Heterorotula fistula, which formed large deposits in neighbouring areas. The high silica concentration, derived from the dome volcanic rocks, constant water level and available substrate are credited for the continuous production of sponges and spicules, confirmed by the rare presence of gemmoscleres. The lake is classed as a minerotrophic fen type of bog with a heavy contribution from the surrounding creeks. Lake sediments are fine with high levels of organic matter and peat, which contributed to the trapping of spicules in the sediments. PMID:26909621

  10. Possible crater-based karstic and lacustrine terrain in Tyrrhena Terra, Mars.

    NASA Astrophysics Data System (ADS)

    Baioni, Davide; Soare, Richard

    2015-04-01

    We have identified two craters in Tyrrhena Terra, Mars (19.560 S, 67.480 E, 18.500 S, 68.340 E), where crater-floor deposits display traits that are consistent with formation by karst-driven processes. Tyrrhena Terra is located in the cratered highlands of the southern Martian hemisphere, immediately to the northeast of Hellas Planitia and to the southeast of Isidis Planitia. Crater diameters in the region vary widely, from metres to 100km. Most of these craters are moderately to highly degraded and many show bright deposits on their floors. Here, we present some of the key characteristics associated with these bright deposits and explain why a "karstic" formation hypothesis is reasonable. First and foremost amongst these characteristics are depressions that are ubiquitous within the bright deposits. They display a variety of plan forms ranging from rounded, circular, elongated, polygonal and drop-like to elliptical. Moreover, they display strong morphometric (sizes) and morphologic (shapes, bottoms, walls) similarities with the karst depressions that are common on limestone and evaporite terrains on the Earth. Some depression morphologies - rounded/elongate - could be the result of formation by coalescence. We infer that the depressions are dolines, karstic features formed polygenetically by corrosion and solution-related intra-crater processes; we also demonstrate why the formation of the depressions by aeolian, periglacial, volcanic or impact-related processes seems less plausible by karst-related ones. Interestingly, polygonal cracks whose morphology points to an origin by dessication often cross-cut the bright deposits; as such, their crater floor presence could be an important co-marker of ponded or running liquid water within the craters where they are observed.

  11. Functional Analyses of Bitter Taste Receptors in Domestic Cats (Felis catus)

    PubMed Central

    Lei, Weiwei; Ravoninjohary, Aurore; Li, Xia; Margolskee, Robert F.; Reed, Danielle R.; Beauchamp, Gary K.; Jiang, Peihua

    2015-01-01

    Cats are obligate carnivores and under most circumstances eat only animal products. Owing to the pseudogenization of one of two subunits of the sweet receptor gene, they are indifferent to sweeteners, presumably having no need to detect plant-based sugars in their diet. Following this reasoning and a recent report of a positive correlation between the proportion of dietary plants and the number of Tas2r (bitter receptor) genes in vertebrate species, we tested the hypothesis that if bitter perception exists primarily to protect animals from poisonous plant compounds, the genome of the domestic cat (Felis catus) should have lost functional bitter receptors and they should also have reduced bitter receptor function. To test functionality of cat bitter receptors, we expressed cat Tas2R receptors in cell-based assays. We found that they have at least 7 functional receptors with distinct receptive ranges, showing many similarities, along with some differences, with human bitter receptors. To provide a comparative perspective, we compared the cat repertoire of intact receptors with those of a restricted number of members of the order Carnivora, with a range of dietary habits as reported in the literature. The numbers of functional bitter receptors in the terrestrial Carnivora we examined, including omnivorous and herbivorous species, were roughly comparable to that of cats thereby providing no strong support for the hypothesis that a strict meat diet influences bitter receptor number or function. Maintenance of bitter receptor function in terrestrial obligate carnivores may be due to the presence of bitter compounds in vertebrate and invertebrate prey, to the necessary role these receptors play in non-oral perception, or to other unknown factors. We also found that the two aquatic Carnivora species examined had fewer intact bitter receptors. Further comparative studies of factors driving numbers and functions of bitter taste receptors will aid in understanding the forces

  12. Functional Analyses of Bitter Taste Receptors in Domestic Cats (Felis catus).

    PubMed

    Lei, Weiwei; Ravoninjohary, Aurore; Li, Xia; Margolskee, Robert F; Reed, Danielle R; Beauchamp, Gary K; Jiang, Peihua

    2015-01-01

    Cats are obligate carnivores and under most circumstances eat only animal products. Owing to the pseudogenization of one of two subunits of the sweet receptor gene, they are indifferent to sweeteners, presumably having no need to detect plant-based sugars in their diet. Following this reasoning and a recent report of a positive correlation between the proportion of dietary plants and the number of Tas2r (bitter receptor) genes in vertebrate species, we tested the hypothesis that if bitter perception exists primarily to protect animals from poisonous plant compounds, the genome of the domestic cat (Felis catus) should have lost functional bitter receptors and they should also have reduced bitter receptor function. To test functionality of cat bitter receptors, we expressed cat Tas2R receptors in cell-based assays. We found that they have at least 7 functional receptors with distinct receptive ranges, showing many similarities, along with some differences, with human bitter receptors. To provide a comparative perspective, we compared the cat repertoire of intact receptors with those of a restricted number of members of the order Carnivora, with a range of dietary habits as reported in the literature. The numbers of functional bitter receptors in the terrestrial Carnivora we examined, including omnivorous and herbivorous species, were roughly comparable to that of cats thereby providing no strong support for the hypothesis that a strict meat diet influences bitter receptor number or function. Maintenance of bitter receptor function in terrestrial obligate carnivores may be due to the presence of bitter compounds in vertebrate and invertebrate prey, to the necessary role these receptors play in non-oral perception, or to other unknown factors. We also found that the two aquatic Carnivora species examined had fewer intact bitter receptors. Further comparative studies of factors driving numbers and functions of bitter taste receptors will aid in understanding the forces

  13. Bitter taste receptor T2R1 activities were compatible with behavioral sensitivity to bitterness in chickens.

    PubMed

    Hirose, Nozomi; Kawabata, Yuko; Kawabata, Fuminori; Nishimura, Shotaro; Tabata, Shoji

    2015-05-01

    Clarification of the mechanism of the sense of taste in chickens will provide information useful for creating and improving new feedstuffs for chickens, because the character of the taste receptors in oral tissues affects feeding behavior in animals. In this study, we focused on the sensitivity to bitterness in chickens. We cloned one of the bitter taste receptors, T2R1, from the chicken palate, constructed several biosensor-cells expressing chicken T2R1 (cT2R1), and determined a highly sensitive biosensor of cT2R1 among them. By using Ca(2+) imaging methods, we identified two agonists of cT2R1, dextromethorphan (Dex) and diphenidol (Dip). Dex was a new agonist of cT2R1 that was more potent than Dip. In a behavioral drinking study, the intake volumes of solutions of these compounds were significantly lower than that of water in chickens. These aversive concentrations were identical to the concentrations that could activate cT2R1 in a cell-based assay. These results suggest that the cT2R1 activities induced by these agonists are linked to behavioral sensitivity to bitterness in chickens.

  14. Factors affecting the bitterness intensities of ten commercial formulations of ambroxol.

    PubMed

    Uchida, Takahiro; Sugino, Yuka; Hazekawa, Mai; Yoshida, Miyako; Haraguchi, Tamami

    2012-01-01

    The bitterness of 10 different products with ambroxol as active ingredient, the original and nine generics, were evaluated by human gustatory sensation tests in which the tablets were kept in the mouth, with water, at 20 and 37°C. The products all showed different bitterness intensities. The original and some of the generic products had comparatively low bitterness intensities but some of the generic products had comparatively high bitterness intensities. The bitterness intensities of these 10 was found to be significantly correlated with both the disintegration time, as evaluated using the ODT-101 (a recently developed apparatus), and the drug concentration in dissolved medium, as measured in a conventional dissolution test. The bitterness threshold of ambroxol solution was found to increase when the temperature of the water with which the tablets were taken, was raised from 20 to 37°C. The equation was calculated to predict the bitterness intensity of ambroxol, a function based on temperature and the ambroxol concentration using data from a standard ambroxol solution at 4, 20 and 37°C. The bitterness intensities obtained for the 10 ambroxol formulations with water at 20 and 37°C, coincided with the bitterness values predicted by the equation.

  15. Factors affecting the bitterness intensities of ten commercial formulations of ambroxol.

    PubMed

    Uchida, Takahiro; Sugino, Yuka; Hazekawa, Mai; Yoshida, Miyako; Haraguchi, Tamami

    2012-01-01

    The bitterness of 10 different products with ambroxol as active ingredient, the original and nine generics, were evaluated by human gustatory sensation tests in which the tablets were kept in the mouth, with water, at 20 and 37°C. The products all showed different bitterness intensities. The original and some of the generic products had comparatively low bitterness intensities but some of the generic products had comparatively high bitterness intensities. The bitterness intensities of these 10 was found to be significantly correlated with both the disintegration time, as evaluated using the ODT-101 (a recently developed apparatus), and the drug concentration in dissolved medium, as measured in a conventional dissolution test. The bitterness threshold of ambroxol solution was found to increase when the temperature of the water with which the tablets were taken, was raised from 20 to 37°C. The equation was calculated to predict the bitterness intensity of ambroxol, a function based on temperature and the ambroxol concentration using data from a standard ambroxol solution at 4, 20 and 37°C. The bitterness intensities obtained for the 10 ambroxol formulations with water at 20 and 37°C, coincided with the bitterness values predicted by the equation. PMID:22863696

  16. Bitterness prediction of H1-antihistamines and prediction of masking effects of artificial sweeteners using an electronic tongue.

    PubMed

    Ito, Masanori; Ikehama, Kiyoharu; Yoshida, Koichi; Haraguchi, Tamami; Yoshida, Miyako; Wada, Koichi; Uchida, Takahiro

    2013-01-30

    The study objective was to quantitatively predict a drug's bitterness and estimate bitterness masking efficiency using an electronic tongue (e-Tongue). To verify the predicted bitterness by e-Tongue, actual bitterness scores were determined by human sensory testing. In the first study, bitterness intensities of eight H(1)-antihistamines were assessed by comparing the Euclidean distances between the drug and water. The distances seemed not to represent the drug's bitterness, but to be greatly affected by acidic taste. Two sensors were ultimately selected as best suited to bitterness evaluation, and the data obtained from the two sensors depicted the actual taste map of the eight drugs. A bitterness prediction model was established with actual bitterness scores from human sensory testing. Concerning basic bitter substances, such as H(1)-antihistamines, the predictability of bitterness intensity using e-Tongue was considered to be sufficiently promising. In another study, the bitterness masking efficiency when adding an artificial sweetener was estimated using e-Tongue. Epinastine hydrochloride aqueous solutions containing different levels of acesulfame potassium and aspartame were well discriminated by e-Tongue. The bitterness masking efficiency of epinastine hydrochloride with acesulfame potassium was successfully predicted using e-Tongue by several prediction models employed in the study.

  17. Transit time distributions to assess present and future contamination risk of karst aquifers over Europe and the Mediterranean

    NASA Astrophysics Data System (ADS)

    Hartmann, Andreas; Gleeson, Tom; Wada, Yoshihide; Wagener, Thorsten

    2016-04-01

    Karst develops through the dissolution of carbonate rock. Karst groundwater in Europe is a major source of fresh water contributing up to half of the total drinking water supply in some countries. Climate model projections suggest that in the next 100 years, karst regions will experience a strong increase in temperature and a serious decrease of precipitation - especially in the Mediterranean region. Previous work showed that the karstic preferential recharge processes result in enhanced recharge rates and future climate sensitivity. But as there is fast water flow form the surface to the aquifer, there is also an enhanced risk of groundwater contamination. In this study we will assess the contamination risk of karst aquifers over Europe and the Mediterranean using simulated transit time distributions. Using a new type of semi-distributed model that considers the spatial heterogeneity of the karst system by distribution functions we simulated a range of spatially variable pathways of karstic groundwater recharge. The model is driven by the bias-corrected 5 GCMs of the ISI-MIP project (RCP8.5). Transit time distributions are calculated by virtual tracer experiments. These are repeated several times in the present (1991-2010) and the future (2080-2099). We can show that regions with larger fractions of preferential recharge show higher risks of contamination and that spatial patterns of contamination risk change towards the future.

  18. The effect of sweeteners on bitter taste in young and elderly subjects.

    PubMed

    Schiffman, S S; Gatlin, L A; Sattely-Miller, E A; Graham, B G; Heiman, S A; Stagner, W C; Erickson, R P

    1994-01-01

    The purpose of this study was to quantify the degree of reduction in perceived bitterness by sweeteners at both threshold and suprathreshold concentrations of bitter compounds. Detection and recognition thresholds were determined for six bitter compounds (caffeine, denatonium benzoate, magnesium chloride, quinine hydrochloride, sucrose octaacetate, and urea) in the absence and presence of several suprathreshold concentrations of five sweeteners. The sweeteners were: sucrose, aspartame, sodium saccharin, mannitol, and sorbitol. Polycose was also tested along with the sweeteners. The degree to which bitter thresholds were affected by the addition of sweeteners was dependent on the chemical classification of the sweeteners and their concentrations. In general, the natural sweeteners, sucrose, mannitol, and sorbitol, were more effective than the noncaloric sweeteners, aspartame and sodium saccharin, in elevating the detection and recognition thresholds of the bitter compounds. A sweetness intensity approximating that of 6% sucrose (0.175 M sucrose) or greater was required to elevate thresholds. For elderly subjects, sweeteners did not significantly elevate thresholds for denatonium benzoate and sucrose octaacetate. The degree to which sorbitol and sucrose can decrease the perceived bitterness intensity of suprathreshold concentrations of the six bitter compounds was also determined. The concentrations of sweeteners and bitter compounds were selected to be of moderate to high subjective intensity. The levels of sweeteners used in the mixtures were: sucrose (none, 0.946 M, and 2.13 M) and sorbitol (none, 2.1 M, and 3.68 M). Both sweeteners significantly reduced the bitterness ratings of almost every concentration of the six bitter compounds. The greatest reductions in bitterness were 87.0% for 0.192 microM denatonium benzoate mixed with 2.13 M sucrose and 84.7% for 1.8 M urea mixed with 3.68 M sorbitol.

  19. The large karstic holes at the top of the Syrian coastal Mountain Range. Importance of structural setting for the karstogenesis.

    NASA Astrophysics Data System (ADS)

    Mocochain, Ludovic; Blanpied, Christian; Bigot, Jean-Yves; Peyronel, Olivier; Gorini, Christian; Abdalla, Abdelkarim Al; Azki, Fawaz

    2015-04-01

    Along the Eastern Mediterranean Sea, the Syria Coastal Mountain Range spreads from north to south over 150 km of long. This range is a monocline structure stopped by a major escarpment that domines Al-Gahb Graben to the East. The Coastal Mountain Range is mainly formed by Mesozoic limestone that show a major unconformity between the Upper Jurassic and Aptien deposits, and important erosions in the Upper Cretaceous deposits. Locally, the Juro-Cretaceous unconformity is characterized by a layer of continental basalts with fossil woods that reveal a long emersion of the platform. The most recent carbonate deposits at the top of the Coastal Mountain Range are Turonian age. In the center part of the Coastal Mountain Range, in a small area, the Cretaceous carbonates are affected by large karstic dolines. These dolines are curiously located at the top of the mountain range. This position is not beneficial for the development of large karstic holes.

  20. Electrical Resistivity Tomography (ERT) Applied to Karst Carbonate Aquifers: Case Study from Amdoun, Northwestern Tunisia

    NASA Astrophysics Data System (ADS)

    Redhaounia, Belgacem; Ilondo, Batobo Ountsche; Gabtni, Hakim; Sami, Khomsi; Bédir, Mourad

    2016-04-01

    The Amdoun region is characterized by a high degree of karstification due to the climate impact (±1500 mm year-1) and the development of fracture network. Survey using electrical resistivity tomography (ERT) is deployed to provide a cost-effective characterization of the subsurface karst environments. A total of seven ERT profiles with lengths of 315 m were evaluated at the Béja governorate (NW Tunisia). The area represents a small syncline of Boudabbous limestone rocks (Lower Eocene), which is covered by a thin layer of clay. In this study, an ERT survey was conducted to examine the spatial distribution and shape of underground cavities in the karst area in Jebel Sabah anticline and Aïn Sallem-Zahret Medien syncline. In this study, geological, hydro-geological and electrical resistivity tomography (ERT) methods were applied to determine the geometry of the perched aquifer in the Amdoun region (NW Tunisia). The area is characterized by fractured and karstic limestone aquifer of Late Cretaceous (Abiod Fm.) and Lower Eocene (Boudabbous Fm.). The aquifers have a karstic functioning and drain aquifers of economical interest, despite some wells exploiting them. Seven resistivity profiles were conducted along the survey area at three sites. The orientation, extension and the degree of inclination of those profiles are shown in the location map. The correct resistivity data were interpreted using Earth Imager 2D software. The results of the interpreted geo-electrical sections showed that the resistivity of the carbonate aquifer varied between 2.5 to over 5794 Ωm. The thickness of the perched aquifer ranged from 15 to 50 m, while its depth from the surface lies between 10 and 60 m. The ERT not only provided precise near surface information, but was also very useful for establishing the 3D geometry and the position of several potential cavities and karts. The results show the presence of small to large isolated cavities at various depths. The low resistivity of cavities

  1. Regulation of bitter taste responses by tumor necrosis factor

    PubMed Central

    Feng, Pu; Jyotaki, Masafumi; Kim, Agnes; Chai, Jinghua; Simon, Nirvine; Zhou, Minliang; Bachmanov, Alexander A.; Huang, Liquan; Wang, Hong

    2015-01-01

    Inflammatory cytokines are important regulators of metabolism and food intake. Over production of inflammatory cytokines during bacterial and viral infections leads to anorexia and reduced food intake. However, it remains unclear whether any inflammatory cytokines are involved in the regulation of taste reception, the sensory mechanism governing food intake. Previously, we showed that tumor necrosis factor (TNF), a potent proinflammatory cytokine, is preferentially expressed in a subset of taste bud cells. The level of TNF in taste cells can be further induced by inflammatory stimuli. To investigate whether TNF plays a role in regulating taste responses, in this study, we performed taste behavioral tests and gustatory nerve recordings in TNF knockout mice. Behavioral tests showed that TNF-deficient mice are significantly less sensitive to the bitter compound quinine than wild-type mice, while their responses to sweet, umami, salty, and sour compounds are comparable to those of wild-type controls. Furthermore, nerve recording experiments showed that the chorda tympani nerve in TNF knockout mice is much less responsive to bitter compounds than that in wild-type mice. Chorda tympani nerve responses to sweet, umami, salty, and sour compounds are similar between TNF knockout and wild-type mice, consistent with the results from behavioral tests. We further showed that taste bud cells express the two known TNF receptors TNFR1 and TNFR2 and, therefore, are potential targets of TNF. Together, our results suggest that TNF signaling preferentially modulates bitter taste responses. This mechanism may contribute to taste dysfunction, particularly taste distortion, associated with infections and some chronic inflammatory diseases. PMID:25911043

  2. Regulation of bitter taste responses by tumor necrosis factor.

    PubMed

    Feng, Pu; Jyotaki, Masafumi; Kim, Agnes; Chai, Jinghua; Simon, Nirvine; Zhou, Minliang; Bachmanov, Alexander A; Huang, Liquan; Wang, Hong

    2015-10-01

    Inflammatory cytokines are important regulators of metabolism and food intake. Over production of inflammatory cytokines during bacterial and viral infections leads to anorexia and reduced food intake. However, it remains unclear whether any inflammatory cytokines are involved in the regulation of taste reception, the sensory mechanism governing food intake. Previously, we showed that tumor necrosis factor (TNF), a potent proinflammatory cytokine, is preferentially expressed in a subset of taste bud cells. The level of TNF in taste cells can be further induced by inflammatory stimuli. To investigate whether TNF plays a role in regulating taste responses, in this study, we performed taste behavioral tests and gustatory nerve recordings in TNF knockout mice. Behavioral tests showed that TNF-deficient mice are significantly less sensitive to the bitter compound quinine than wild-type mice, while their responses to sweet, umami, salty, and sour compounds are comparable to those of wild-type controls. Furthermore, nerve recording experiments showed that the chorda tympani nerve in TNF knockout mice is much less responsive to bitter compounds than that in wild-type mice. Chorda tympani nerve responses to sweet, umami, salty, and sour compounds are similar between TNF knockout and wild-type mice, consistent with the results from behavioral tests. We further showed that taste bud cells express the two known TNF receptors TNFR1 and TNFR2 and, therefore, are potential targets of TNF. Together, our results suggest that TNF signaling preferentially modulates bitter taste responses. This mechanism may contribute to taste dysfunction, particularly taste distortion, associated with infections and some chronic inflammatory diseases. PMID:25911043

  3. Regulation of bitter taste responses by tumor necrosis factor.

    PubMed

    Feng, Pu; Jyotaki, Masafumi; Kim, Agnes; Chai, Jinghua; Simon, Nirvine; Zhou, Minliang; Bachmanov, Alexander A; Huang, Liquan; Wang, Hong

    2015-10-01

    Inflammatory cytokines are important regulators of metabolism and food intake. Over production of inflammatory cytokines during bacterial and viral infections leads to anorexia and reduced food intake. However, it remains unclear whether any inflammatory cytokines are involved in the regulation of taste reception, the sensory mechanism governing food intake. Previously, we showed that tumor necrosis factor (TNF), a potent proinflammatory cytokine, is preferentially expressed in a subset of taste bud cells. The level of TNF in taste cells can be further induced by inflammatory stimuli. To investigate whether TNF plays a role in regulating taste responses, in this study, we performed taste behavioral tests and gustatory nerve recordings in TNF knockout mice. Behavioral tests showed that TNF-deficient mice are significantly less sensitive to the bitter compound quinine than wild-type mice, while their responses to sweet, umami, salty, and sour compounds are comparable to those of wild-type controls. Furthermore, nerve recording experiments showed that the chorda tympani nerve in TNF knockout mice is much less responsive to bitter compounds than that in wild-type mice. Chorda tympani nerve responses to sweet, umami, salty, and sour compounds are similar between TNF knockout and wild-type mice, consistent with the results from behavioral tests. We further showed that taste bud cells express the two known TNF receptors TNFR1 and TNFR2 and, therefore, are potential targets of TNF. Together, our results suggest that TNF signaling preferentially modulates bitter taste responses. This mechanism may contribute to taste dysfunction, particularly taste distortion, associated with infections and some chronic inflammatory diseases.

  4. Bitter melon: a panacea for inflammation and cancer.

    PubMed

    Dandawate, Prasad R; Subramaniam, Dharmalingam; Padhye, Subhash B; Anant, Shrikant

    2016-02-01

    Nature is a rich source of medicinal plants and their products that are useful for treatment of various diseases and disorders. Momordica charantia, commonly known as bitter melon or bitter gourd, is one of such plants known for its biological activities used in traditional system of medicines. This plant is cultivated in all over the world, including tropical areas of Asia, Amazon, east Africa, and the Caribbean and used as a vegetable as well as folk medicine. All parts of the plant, including the fruit, are commonly consumed and cooked with different vegetables, stir-fried, stuffed or used in small quantities in soups or beans to give a slightly bitter flavor and taste. The plant is reported to possess anti-oxidant, anti-inflammatory, anti-cancer, anti-diabetic, anti-bacterial, anti-obesity, and immunomodulatory activities. The plant extract inhibits cancer cell growth by inducing apoptosis, cell cycle arrest, autophagy and inhibiting cancer stem cells. The plant is rich in bioactive chemical constituents like cucurbitane type triterpenoids, triterpene glycosides, phenolic acids, flavonoids, essential oils, saponins, fatty acids, and proteins. Some of the isolated compounds (Kuguacin J, Karaviloside XI, Kuguaglycoside C, Momordicoside Q-U, Charantin, α-eleostearic acid) and proteins (α-Momorcharin, RNase MC2, MAP30) possess potent biological activity. In the present review, we are summarizing the anti-oxidant, anti-inflammatory, and anti-cancer activities of Momordica charantia along with a short account of important chemical constituents, providing a basis for establishing detail biological activities of the plant and developing novel drug molecules based on the active chemical constituents. PMID:26968675

  5. Salt Water Intrusion Modeling of an Aquifer in the Northwest of Maharlu Lake

    NASA Astrophysics Data System (ADS)

    Ghader, Fatemeh; Zaree, Mohammad

    2010-05-01

    Coastal aquifers are important supply sources of fresh water in numerous area of earth. The problem of saltwater intrusion has been widely caused the deterioration of water qulity in these sources. As fresh water flows from the aquifer near the coastline. Eventually dynamic equilibrium is reached between the fresh and saltwater. Intrusion of pumping wells within coastal aquifer has the potential to disturb this equilibrium. Maharloo Lake is a salt lake located 27 km southeast of Shiraz. There are many fresh coastal aquifera around this lake that naturally are recharged by fresh water entering from the landward karstic aquifer. The hydraulic equilibrium could be disturbed due to large extraction rate and consequently dropping in groundwater table. So, the lake saltwater with high salinity (Ec more than 300ms/cm in summer) coukd flow toward the aquifer. This lake salinity is much more than oceans salinity, so aquifer salinity could be changed very much even at low equilibrium disturbance. As a result, the management and maintenance of this aquifer is very important. The object of this research is preparation of an intrusion model of a coastal aquifer at the northwestern of Maharloo Lake, where the coastal aquifer is the single supply source of fresh water and the saltwater intrusion has been widely caused the deterioration of water quality. In this study SEAWAT computer code, a three dimensional finit difference model, used to study the intrusion mechanisms and groundwater systems. After data collection including qualitative and quantitative data and geology and hydrogeology of study area in the field, a conseptual model were prepared. On the basis of collected data, condition of the aquifer in February 2008 were taken as the initial condition and the length of calibration and verification periods consequently take 150 and 121 days after this time. After model calibration and verification, the aquifer conditions for next year predicted on the basis of two following

  6. Assessing climate change impacts on runoff from karstic watersheds: NASA/GISS land-surface model improvement

    NASA Astrophysics Data System (ADS)

    Blake, Reginald Alexander

    The off-line version of the Goddard Institute for Space Studies (GISS) land-surface hydrological model over- predicted run-off from the karstic Rio Cobre watershed in Jamaica. To assess possible climate change impacts on runoff from the watershed, the model's simulation of observed runoff was improved by adding to it a karst component that has pipe flow features. The improved model was tested on two other karstic watersheds (Yangtze - China and Rio Grande - USA) and the results were encouraging. The impacts that possible climate change may have on the three karstic watersheds were then assessed. The assessment indicates that in a doubled carbon dioxide climate, the Rio Cobre and the Rio Grande may experience decreases in runoff, especially in low flow periods. The Yangtze, on the other hand, may not experience decreases in total runoff, but its peak flow which now occurs in July may be attenuated and shifted to September. The results of the study also show that climate feedbacks convolute climate change assessments and that different results can be obtained from the same climate change scenario depending on the choice of the modeling methodology-that is, on whether the models are coupled or uncoupled.

  7. Detailed Analysis of a Bitter-Type Magnet

    NASA Astrophysics Data System (ADS)

    Nakagawa, Yasuaki; Miura, Shigeto; Hoshi, Akira; Nakajima, Kikuo; Takano, Hirohisa

    1983-06-01

    A high-power water-cooled magnet with a Bitter-type coil has been designed, constructed and tested. The current density, the temperature rise and the electromagnetic stress have been calculated with the finite element method. The results of calculation are consistent with the experimental test. The local electromagnetic stress exceeds the yield stress of usual conductors if the coil is used for hybrid magnet which produces fields of more than 20 T with a back-up field of a superconducting coil.

  8. Bitter avoidance in guinea pigs (Cavia porcellus) and mice (Mus musculus and Peromyscus leucopus).

    PubMed

    Field, Kristin L; Beauchamp, Gary K; Kimball, Bruce A; Mennella, Julie A; Bachmanov, Alexander A

    2010-11-01

    Rejection of bitter substances is common in many species and may function to protect an animal from ingestion of bitter-tasting toxins. Since many plants are bitter, it has been proposed that high tolerance for bitterness would be adaptive for herbivores. Earlier studies conducted on herbivorous guinea pigs (Cavia porcellus) have been used to support this proposal. We tested guinea pigs with bitter plant secondary metabolites (salicin, caffeine, quinine hydrochloride) and bitter protein hydrolysates (two types of hydrolyzed casein, hydrolyzed soy) in a series of two-choice preference tests. For comparison, we tested two nonherbivorous mouse species (Mus musculus and Peromyscus leucopus). Guinea pigs did show weaker avoidance of quinine hydrochloride than did the mice, confirming predictions generated from earlier work. However, guinea pigs had similar responses to caffeine as did Peromyscus. Both of these species showed weaker avoidance responses than Mus to 10 mM caffeine. For salicin, guinea pigs were the only species to avoid it at 10 mM and their preference scores at this concentration were significantly lower than for the two mice species. Guinea pigs avoided all of the protein hydrolysates more strongly than the other species. Responses to the protein hydrolysates did not reflect the patterns observed with the simple bitter compounds, suggesting that other properties of these complex stimuli may be responsible for guinea pig avoidance of them. Our results suggest caution in accepting, without further empirical support, the premise that guinea pigs (and herbivores in general) have a generalized reduced bitter sensitivity. PMID:21090891

  9. Interactions and thresholds of limonin and nomilin in bitterness perception in orange juice and other matrices

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Limonin and nomilin are two bitter compounds present in citrus and are thought to cause the bitter off-flavor of Huanglongbing-infected fruit/juice. This study determined the thresholds of limonin, nomilin, and their combination in a simple matrix (sucrose and citric acid), a complex matrix (sucrose...

  10. Bitter avoidance in guinea pigs (Cavia porcellus) and mice (Mus musculus and Peromyscus leucopus).

    PubMed

    Field, Kristin L; Beauchamp, Gary K; Kimball, Bruce A; Mennella, Julie A; Bachmanov, Alexander A

    2010-11-01

    Rejection of bitter substances is common in many species and may function to protect an animal from ingestion of bitter-tasting toxins. Since many plants are bitter, it has been proposed that high tolerance for bitterness would be adaptive for herbivores. Earlier studies conducted on herbivorous guinea pigs (Cavia porcellus) have been used to support this proposal. We tested guinea pigs with bitter plant secondary metabolites (salicin, caffeine, quinine hydrochloride) and bitter protein hydrolysates (two types of hydrolyzed casein, hydrolyzed soy) in a series of two-choice preference tests. For comparison, we tested two nonherbivorous mouse species (Mus musculus and Peromyscus leucopus). Guinea pigs did show weaker avoidance of quinine hydrochloride than did the mice, confirming predictions generated from earlier work. However, guinea pigs had similar responses to caffeine as did Peromyscus. Both of these species showed weaker avoidance responses than Mus to 10 mM caffeine. For salicin, guinea pigs were the only species to avoid it at 10 mM and their preference scores at this concentration were significantly lower than for the two mice species. Guinea pigs avoided all of the protein hydrolysates more strongly than the other species. Responses to the protein hydrolysates did not reflect the patterns observed with the simple bitter compounds, suggesting that other properties of these complex stimuli may be responsible for guinea pig avoidance of them. Our results suggest caution in accepting, without further empirical support, the premise that guinea pigs (and herbivores in general) have a generalized reduced bitter sensitivity.

  11. Effects of Jamaican bitter yam (Dioscorea polygonoides) and diosgenin on blood and fecal cholesterol in rats.

    PubMed

    McKoy, Marsha-Lyn; Thomas, Peta-Gaye; Asemota, Helen; Omoruyi, Felix; Simon, Oswald

    2014-11-01

    A sapogenin-rich preparation from Jamaican bitter yam (Dioscorea polygonoides) has been shown to reduce blood cholesterol concentrations in hypercholesterolemic rats and mice. Also, diosgenin supplementation has been reported to have antilipemic effects in several animal species. We investigated potential mechanisms of the lipid-lowering actions of bitter yam and also whether the actions were mediated by diosgenin. Sprague-Dawley rats were fed a hypercholesterolemic diet (4% cholesterol) alone or with 5% bitter yam or 1% diosgenin supplementation for 6 weeks. The control group was fed normal rat chow. The serum lipid profile, fecal cholesterol concentration, and serum lipase activity were assessed at the end of the period. The induction of hypercholesterolemia was inhibited by coadministration of 5% bitter yam or 1% diosgenin in the diet. Serum lipid profiles were similar in rats fed bitter yam or diosgenin. The fecal cholesterol concentration was significantly (P < .01) higher in rats fed diosgenin compared to the cholesterol group. However, there was no corresponding elevation in the group fed bitter yam. Administration of bitter yam or diosgenin supplement significantly increased (P < .01) the serum lipase activity compared to the normal control and cholesterol groups. The cholesterol-supplemented diet inhibited normal gain in body weight over the period. This action was potentiated by diosgenin. The effects of the respective supplements on body weight were not completely explained by food consumption. Supplementation of the diet with Jamaican bitter yam may be therapeutically beneficial in the management of hypercholesterolemia.

  12. Modeling the groundwater recharge in karst aquifers by using a reservoir model.

    PubMed

    Ke, Tingting; Shu, Longcang; Chen, Xunhong

    2013-01-01

    The estimation of the groundwater recharge in a karstic system becomes an important challenge due to the great hydrodynamic variability in both time and space. This paper proposes a two reservoir conceptual model to simulate inflow into both the conduit system and the fissure network system based on the analysis of the spring hydrograph. The structure of the model and the governing equations are proposed on the basis of the physical considerations, with the assumption that flow at the outlet of the reservoirs obeys a linear threshold function. The model is applied on the Houzhai karstic underground river basin where it successfully reflects the temporal recharge distribution. The simulated accumulation recharge is 34.29 mm, which is reasonable in relation to the actual rainfall of 92.8 mm. The variations of water volume in two reservoirs represent the storage and transform characteristics of the karst aquifer system. However, this model is particularly well suited to simulate the recharge event after intensive rainfall.

  13. Acid sensing by sweet and bitter taste neurons in Drosophila melanogaster

    PubMed Central

    Charlu, Sandhya; Wisotsky, Zev; Medina, Adriana; Dahanukar, Anupama

    2013-01-01

    Drosophila melanogaster can taste various compounds and separate them into few basic categories such as sweet, bitter and salt taste. Here we investigate mechanisms underlying acid detection in Drosophila and report that the fly displays strong taste aversion to common carboxylic acids. We find that acid tastants act by the activation of a subset of bitter neurons and inhibition of sweet neurons. Bitter neurons begin to respond at pH 5 and show an increase in spike frequency as the extracellular pH drops, which does not rely on previously identified chemoreceptors. Notably, sweet neuron activity depends on the balance of sugar and acid tastant concentrations. This is independent of bitter neuron firing, and allows the fly to avoid acid-laced food sources even in the absence of functional bitter neurons. The two mechanisms may allow the fly to better evaluate the risk of ingesting acidic foods and modulate its feeding decisions accordingly. PMID:23783889

  14. Application of isothermal titration calorimeter for screening bitterness-suppressing molecules of quinine.

    PubMed

    Zhang, Yifan; Zhu, Youwei; Zhao, Na; Wu, Jinhui; Hu, Yiqiao

    2016-01-01

    Bitterness-suppressing molecules have drawn ever-increasing attention these years for some unique advantages like low molecular weight, tastelessness and no interference on drug bioavailability. L-Arg was reported to suppress the bitterness of quinine, and we happened to find that the suppressing effects could be demonstrated by isothermal titration calorimeter (ITC). In this study, we investigated the possibility of using ITC to screen bitterness-suppressing molecules for quinine. Among the amino acids we screened, L-Lys bond quinine with high affinity. The results of ITC correlated well with the results of human sensory experiments. L-Arg and L-Lys could suppress the bitterness of quinine while other amino acids could not. Therefore, ITC has the potential to screen bitterness-suppressing molecules.

  15. Central relay of bitter taste to the protocerebrum by peptidergic interneurons in the Drosophila brain.

    PubMed

    Hückesfeld, Sebastian; Peters, Marc; Pankratz, Michael J

    2016-01-01

    Bitter is a taste modality associated with toxic substances evoking aversive behaviour in most animals, and the valence of different taste modalities is conserved between mammals and Drosophila. Despite knowledge gathered in the past on the peripheral perception of taste, little is known about the identity of taste interneurons in the brain. Here we show that hugin neuropeptide-containing neurons in the Drosophila larval brain are necessary for avoidance behaviour to caffeine, and when activated, result in cessation of feeding and mediates a bitter taste signal within the brain. Hugin neuropeptide-containing neurons project to the neurosecretory region of the protocerebrum and functional imaging demonstrates that these neurons are activated by bitter stimuli and by activation of bitter sensory receptor neurons. We propose that hugin neurons projecting to the protocerebrum act as gustatory interneurons relaying bitter taste information to higher brain centres in Drosophila larvae. PMID:27619503

  16. Central relay of bitter taste to the protocerebrum by peptidergic interneurons in the Drosophila brain

    PubMed Central

    Hückesfeld, Sebastian; Peters, Marc; Pankratz, Michael J.

    2016-01-01

    Bitter is a taste modality associated with toxic substances evoking aversive behaviour in most animals, and the valence of different taste modalities is conserved between mammals and Drosophila. Despite knowledge gathered in the past on the peripheral perception of taste, little is known about the identity of taste interneurons in the brain. Here we show that hugin neuropeptide-containing neurons in the Drosophila larval brain are necessary for avoidance behaviour to caffeine, and when activated, result in cessation of feeding and mediates a bitter taste signal within the brain. Hugin neuropeptide-containing neurons project to the neurosecretory region of the protocerebrum and functional imaging demonstrates that these neurons are activated by bitter stimuli and by activation of bitter sensory receptor neurons. We propose that hugin neurons projecting to the protocerebrum act as gustatory interneurons relaying bitter taste information to higher brain centres in Drosophila larvae. PMID:27619503

  17. Physico-chemical evaluation of bitter and non-bitter Aloe and their raw juice for human consumption.

    PubMed

    Azam, M M; Kumar, S; Pancholy, A; Patidar, M

    2014-11-01

    In addition to Aloe vera which is bitter in taste, a non-bitter Aloe is also found in arid part of Rajasthan. This non-bitter Aloe (NBA) is sporadically cultivated as vegetable and for health drink. In spite of its cultivation and various uses, very little information is available about its detailed botanical parameters and chemical characters. This study aims to evaluate the physico-chemical characters of NBA through employing floral morphology, leaf characters and leaf gel and to compare them with those of A. vera. Of eleven floral characters studied, eight characters of NBA were significantly different from that of A. vera. Most visible difference was observed in their reproductive shoots which are highly branched in NBA (5.21 inflorescence/shoot) as compared to A. vera (1.5 inflorescence/shoot). NBA produces less leaf-biomass (-29.32 %) with less leaf-thickness (-31.44 %) but higher leaf length, width, and no. of spine/side by 17.56 %, 21.34 % and 16.11 %, respectively, with significant difference as compared to A. vera. But its polysaccharide content (0.259 %) is at par with that of A. vera. The raw juice from the leaf of NBA has very low aloin content (4.1 ppm) compared to that from A. vera (427.3 ppm) making it a safer health drink compared to the one obtained from A. vera. Thus, NBA raw juice emerged as suitable alternative to A. vera juice for human consumption.

  18. Genetic Diversity Analysis of Indian Bitter Gourd (Momordica Charantia L.) Allows for the Development of Crop Improvement Strategies

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bitter gourd (Momordica charantia L. var. minima and var. maxima) or bitter melon is one of the most economically important cucurbit species worldwide. Although India is the center of origin of bitter melon, and cultivars and landraces of this species are widely cultivated in Asia, a rigorous asses...

  19. Explaining tolerance for bitterness in chocolate ice cream using solid chocolate preferences.

    PubMed

    Harwood, Meriel L; Loquasto, Joseph R; Roberts, Robert F; Ziegler, Gregory R; Hayes, John E

    2013-08-01

    Chocolate ice cream is commonly formulated with higher sugar levels than nonchocolate flavors to compensate for the inherent bitterness of cocoa. Bitterness, however, is an integral part of the complex flavor of chocolate. In light of the global obesity epidemic, many consumers and health professionals are concerned about the levels of added sugars in foods. Once a strategy for balancing undesirable bitterness and health concerns regarding added sugars has been developed, the task becomes determining whether that product will be acceptable to the consumer. Thus, the purpose of this research was to manipulate the bitterness of chocolate ice cream to examine how this influences consumer preferences. The main goal of this study was to estimate group rejection thresholds for bitterness in chocolate ice cream, and to see if solid chocolate preferences (dark vs. milk) generalized to ice cream. A food-safe bitter ingredient, sucrose octaacetate, was added to chocolate ice cream to alter bitterness without disturbing other the sensory qualities of the ice cream samples, including texture. Untrained chocolate ice cream consumers participated in a large-scale sensory test by indicating their preferences for blinded pairs of unspiked and spiked samples, where the spiked sample had increasing levels of the added bitterant. As anticipated, the group containing individuals who prefer milk chocolate had a much lower tolerance for bitterness in their chocolate ice cream compared with the group of individuals who prefer dark chocolate; indeed, the dark chocolate group tolerated almost twice as much added bitterant in the ice cream before indicating a significant preference for the unspiked (control) ice cream. This work demonstrates the successful application of the rejection threshold method to a complex dairy food. Estimating rejection thresholds could prove to be an effective tool for determining acceptable formulations or quality limits when considering attributes that become

  20. Genetic variation in bitter taste receptor genes influences the foraging behavior of plateau zokor (Eospalax baileyi).

    PubMed

    Zhao, Fang; Zhang, Tongzuo; Xie, Jiuxiang; Zhang, Shoudong; Nevo, Eviatar; Su, Jianping; Lin, Gonghua

    2016-04-01

    The ability to detect bitter tastes is important for animals; it can help them to avoid ingesting harmful substances. Bitter taste perception is mainly mediated by bitter taste receptor proteins, which are encoded by members of the Tas2r gene family and vary with the dietary preference of a specific species. Although individuals with different genotypes differ in bitterness recognition capability, little is known about the relationship between genetic variation and food selection tendencies at the intraspecific level. In this study, we examined the relationship between genotypes and diet in plateau zokor (Eospalax baileyi), a subterranean rodent endemic to the Qinghai-Tibet Plateau that caches food for the winter. We assayed the composition and taste profile of each plant contained in temporary caches and vicinity quadrats, which were representative of selected and available food, respectively. Bitter plant selection indices (E bitter) were estimated. We also sequenced 26 candidate Tas2r genes from zokors and determined their relationships with the E bitter of their caches. We identified four key results: (1) zokors varied considerably in both bitter food preference and Tas2r sequences; (2) five genes (zTas2r115,zTas2r119,zTas2r126,zTas2r134, and zTas2r136) exhibited allelic variation that was significantly associated with E bitter; (3) synonymous SNPs, nonsynonymous SNPs, and pseudogenization are involved in the genotype-phenotype relationship; (4) the minor genotypes of zTas2r115,zTas2r134, and zTas2r136 and the major genotypes of zTas2r119 and zTas2r126 cached more bitter plants. Our results link Tas2r variation with food selection behavior at the population level for the first time. PMID:27110349

  1. Dissolution on Titan and on Earth: Toward the age of Titan's karstic landscapes

    NASA Astrophysics Data System (ADS)

    Cornet, Thomas; Cordier, Daniel; Bahers, Tangui Le; Bourgeois, Olivier; Fleurant, Cyril; Mouélic, Stéphane Le; Altobelli, Nicolas

    2015-06-01

    Titan's polar surface is dotted with hundreds of lacustrine depressions. Based on the hypothesis that they are karstic in origin, we aim at determining the efficiency of surface dissolution as a landshaping process on Titan, in a comparative planetology perspective with the Earth as reference. Our approach is based on the calculation of solutional denudation rates and allow inference of formation timescales for topographic depressions developed by chemical erosion on both planetary bodies. The model depends on the solubility of solids in liquids, the density of solids and liquids, and the average annual net rainfall rates. We compute and compare the denudation rates of pure solid organics in liquid hydrocarbons and of minerals in liquid water over Titan and Earth timescales. We then investigate the denudation rates of a superficial organic layer in liquid methane over one Titan year. At this timescale, such a layer on Titan would behave like salts or carbonates on Earth depending on its composition, which means that dissolution processes would likely occur but would be 30 times slower on Titan compared to the Earth due to the seasonality of precipitation. Assuming an average depth of 100 m for Titan's lacustrine depressions, these could have developed in a few tens of millions of years at polar latitudes higher than 70°N and S, and a few hundreds of million years at lower polar latitudes. The ages determined are consistent with the youth of the surface (<1 Gyr) and the repartition of dissolution-related landforms on Titan.

  2. The nature and distribution of flowing features in a weakly karstified porous limestone aquifer

    NASA Astrophysics Data System (ADS)

    Maurice, L. D.; Atkinson, T. C.; Barker, J. A.; Williams, A. T.; Gallagher, A. J.

    2012-05-01

    SummaryThe nature and distribution of flowing features in boreholes in an area of approximately 400 km2 in a weakly karstic porous limestone aquifer (the Chalk) was investigated using single borehole dilution tests (SBDTs) and borehole imaging. One-hundred and twenty flowing features identified from SBDTs in 24 boreholes have densities which decrease from ∼0.3 m-1 near the water table to ∼0.07 m-1 at depths of more than 40 m below the water table; the average density is 0.20 m-1. There is some evidence of regional lithological control and borehole imaging of three boreholes indicated that most flowing features are associated with marls, hardgrounds and flints that may be developed at a more local scale. Borehole imaging also demonstrated that many flowing features are solutionally enlarged fractures, suggesting that even in carbonate aquifers where surface karst is developed on only a small scale, groundwater flow is still strongly influenced by dissolution. Fully connected solutional pathways can occur over 100s, sometimes 1000s of metres. However, conduits, tubules and fissures may not always be individually persistent along a flowpath, instead being connected together and also connected to unmodified fractures to create a relatively dense network of voids with variable apertures (<0.1 cm to >15 cm). Groundwater therefore moves along flowpaths made up of voids with varying shape and character. Local solutional development of fractures at significant depths below the surface suggests that mixing corrosion and in situ sources of acidity may contribute to solutional enhancement of fractures. The study demonstrates that single borehole dilution testing is a useful method of obtaining a large dataset of flowing features at catchment-regional scales. The Chalk is a carbonate aquifer with small-scale surface karst development and this study raises the question of whether other carbonate aquifers with small-scale surface karst have similar characteristics, and what

  3. Identification of anthropogenic and natural inputs of sulfate into a karstic coastal groundwater system in northeast China: evidence from major ions, δ13CDIC and δ34SSO4

    NASA Astrophysics Data System (ADS)

    Han, Dongmei; Song, Xianfang; Currell, Matthew J.

    2016-05-01

    The hydrogeochemical processes controlling groundwater evolution in the Daweijia area of Dalian, northeast China, were characterised using hydrochemistry and isotopes of carbon and sulfur (δ13CDIC and δ34SSO4). The aim was to distinguish anthropogenic impacts as distinct from natural processes, with a particular focus on sulfate, which is found at elevated levels (range: 54.4 to 368.8 mg L-1; mean: 174.4 mg L-1) in fresh and brackish groundwater. The current investigation reveals minor seawater intrusion impact (not exceeding 5 % of the overall solute load), in contrast with extensive impacts observed in 1982 during the height of intensive abstraction. This indicates that measures to restrict groundwater abstraction have been effective. However, hydrochemical facies analysis shows that the groundwater remains in a state of ongoing hydrochemical evolution (towards Ca-Cl type water) and quality degradation (increasing nitrate and sulfate concentrations). The wide range of NO3 concentrations (74.7-579 mg L-1) in the Quaternary aquifer indicates considerable input of fertilisers and/or leakage from septic systems. Both δ13C (-14.5 to -5.9 permil) and δ34SSO4 (+5.4 to +13.1 permil) values in groundwater show increasing trends along groundwater flow paths. While carbonate minerals may contribute to increasing δ13CDIC and δ34SSO4 values in deep karstic groundwater, high loads of agricultural fertilisers reaching the aquifer via irrigation return flow are likely the main source of the dissolved sulfate in Quaternary groundwater, as shown by distinctive isotopic ratios and a lack of evidence for other sources in the major ion chemistry. According to isotope mass balance calculations, the fertiliser contribution to overall sulfate has reached an average of 62.1 % in the Quaternary aquifer, which has a strong hydraulic connection to the underlying carbonate aquifer. The results point to an alarming level of impact from the local intensive agriculture on the groundwater

  4. The Bad Taste of Medicines: Overview of Basic Research on Bitter Taste

    PubMed Central

    Mennella, Julie A.; Spector, Alan C.; Reed, Danielle R.; Coldwell, Susan E.

    2013-01-01

    Background Many active pharmaceutical ingredients taste bitter and thus are aversive to children, as well as many adults. Encapsulation of the medicine in pill or tablet form, an effective method for adults to avoid the unpleasant taste, is problematic for children. Many children cannot or will not swallow solid dosage forms. Objective This review highlights basic principles of gustatory function, with a special focus on the science of bitter taste, derived from studies of animal models and human psychophysics. We focus on the set of genes that encode the proteins that function as bitter receptors, as well as the cascade of events that lead to multidimensional aspects of taste function, highlighting the role that animal models played in these discoveries. We also summarize psychophysical approaches to studying bitter taste in adult and pediatric populations, highlighting evidence of the similarities and differences in bitter taste perception and acceptance between adults and children and drawing on useful strategies from animal models. Results Medicine often tastes bitter, and because children are more bitter sensitive than are adults, this creates problems with compliance. Bitter arises from stimulating receptors in taste receptor cells, with signals processed in the taste bud and relayed to the brain. However, there are many gaps in our understanding of how best to measure bitterness and how to ameliorate it, including whether it is more efficiently addressed at the level of receptor and sensory signaling, at the level of central processing, or by masking techniques. All methods of measuring responsiveness to bitter ligands—in animal models, through human psychophysics, or with “electronic tongues”—have limitations. Conclusions Better-tasting medications may enhance pediatric adherence to drug therapy. Sugars, acids, salt, and other substances reduce perceived bitterness of several pharmaceuticals, and although pleasant flavorings may help children

  5. A comprehensive review on Nymphaea stellata: A traditionally used bitter.

    PubMed

    Raja, M K Mohan Maruga; Sethiya, Neeraj Kumar; Mishra, S H

    2010-07-01

    Nymphaea stellata Willd. (Syn. Nymphaea nouchali Burman f.) (Nymphaeaceae) is an important and well-known medicinal plant, widely used in the Ayurveda and Siddha systems of medicines for the treatment of diabetes, inflammation, liver disorders, urinary disorders, menorrhagia, blenorrhagia, menstruation problem, as an aphrodisiac, and as a bitter tonic. There seems to be an agreement between the traditional use and experimental observations, such as, hepatoprotective, anti-inflammatory, and particularly antidiabetic activity. Nymphayol, a steroid isolated from the flowers has been scientifically proved to be responsible for the traditionally claimed antidiabetic activity; it reverses the damaged endocrine tissue and stimulates secretion of insulin in the β-cells. However, taking into account the magnitude of its traditional uses, the studies conducted are still negligible. This review is an attempt to provide the pharmaceutical prospective of Nymphaea stellata.

  6. A comprehensive review on Nymphaea stellata: A traditionally used bitter.

    PubMed

    Raja, M K Mohan Maruga; Sethiya, Neeraj Kumar; Mishra, S H

    2010-07-01

    Nymphaea stellata Willd. (Syn. Nymphaea nouchali Burman f.) (Nymphaeaceae) is an important and well-known medicinal plant, widely used in the Ayurveda and Siddha systems of medicines for the treatment of diabetes, inflammation, liver disorders, urinary disorders, menorrhagia, blenorrhagia, menstruation problem, as an aphrodisiac, and as a bitter tonic. There seems to be an agreement between the traditional use and experimental observations, such as, hepatoprotective, anti-inflammatory, and particularly antidiabetic activity. Nymphayol, a steroid isolated from the flowers has been scientifically proved to be responsible for the traditionally claimed antidiabetic activity; it reverses the damaged endocrine tissue and stimulates secretion of insulin in the β-cells. However, taking into account the magnitude of its traditional uses, the studies conducted are still negligible. This review is an attempt to provide the pharmaceutical prospective of Nymphaea stellata. PMID:22247863

  7. Reduction of virgin olive oil bitterness by fruit cold storage.

    PubMed

    Yousfi, Khaled; Cayuela, José A; García, José M

    2008-11-12

    Green mature olives (Olea europaea L. cv. 'Manzanilla', 'Picual', and 'Verdial') were stored at 5 degrees C, and the oil extracted from them showed a middle intensity level of sensory-evaluated bitterness. The storage times necessary for this reduction were different for the three varieties tested, requiring 4, 6, and 8 weeks, respectively, for 'Manzanilla', 'Picual', and 'Verdial' olives. The level of commercial quality of the extracted oil did not deteriorate as a consequence of previous fruit storage. Olives matured during refrigeration at 5 degrees C, as the increase of maturation index and the decrease of color index and fruit firmness indicated. Similarly, as the fruit storage period progressed, the total phenolic compound content of the extracted oils decreased. Although the use of green mature olives may require a more prolonged storage time, it allows for a better postharvest handling of the fruits, which are more resistant to physical damage or fungal infections than the riper ones. PMID:18937491

  8. A comprehensive review on Nymphaea stellata: A traditionally used bitter

    PubMed Central

    Raja, M. K. Mohan Maruga; Sethiya, Neeraj Kumar; Mishra, S. H.

    2010-01-01

    Nymphaea stellata Willd. (Syn. Nymphaea nouchali Burman f.) (Nymphaeaceae) is an important and well-known medicinal plant, widely used in the Ayurveda and Siddha systems of medicines for the treatment of diabetes, inflammation, liver disorders, urinary disorders, menorrhagia, blenorrhagia, menstruation problem, as an aphrodisiac, and as a bitter tonic. There seems to be an agreement between the traditional use and experimental observations, such as, hepatoprotective, anti-inflammatory, and particularly antidiabetic activity. Nymphayol, a steroid isolated from the flowers has been scientifically proved to be responsible for the traditionally claimed antidiabetic activity; it reverses the damaged endocrine tissue and stimulates secretion of insulin in the β-cells. However, taking into account the magnitude of its traditional uses, the studies conducted are still negligible. This review is an attempt to provide the pharmaceutical prospective of Nymphaea stellata. PMID:22247863

  9. Diverse tastes: Genetics of sweet and bitter perception

    PubMed Central

    Reed, Danielle R.; Tanaka, Toshiko; McDaniel, Amanda H.

    2006-01-01

    Humans will eat almost anything, from caribou livers to rutabagas, but there are some types of foods, and their associated taste qualities, that are preferred by large groups of people regardless of culture or experience. When many choices are available, humans chose foods that taste good, that is, create pleasing sensations in the mouth. The concept of good taste for most people encompasses both flavor and texture of food, and these sensations merge with taste proper to form the concept of goodness. Although we acknowledge the universality of the goodness (sweet) or badness (bitter) of basic taste qualities, we also find that people differ, sometimes extremely so, in their ability to perceive and enjoy these qualities and, by extension, food and drink. The reasons for these differences among people are not clear but are probably due to a combination of experience beginning at an early age, perhaps in utero; learning, for example, as with conditioned taste aversions; sex and maturity; and perceptual differences that arise from genetic variation. In this review, we focus on individual variations that arise from genetic differences and review two domains of science: recent developments in the molecular biology of taste transduction, with a focus on the genes involved and second, studies that examine biological relatives to determine the heritability of taste perception. Because the receptors for sweet, savory (umami), and bitter have recently been discovered, we summarize what is known about their function by reviewing the effect of naturally occurring and man-made alleles of these receptors, their shape and function based on receptor modeling techniques, and how they differ across animal species that vary in their ability to taste certain qualities. We discuss this literature in the context of how taste genes may differ among people and give rise to individuated taste experience, and what is currently known about the genetic effects on taste perception in humans

  10. Characterization of bitter taste responses of intestinal STC-1 cells.

    PubMed

    Masuho, Ikuo; Tateyama, Michihiro; Saitoh, Osamu

    2005-05-01

    Cellular responses of STC-1 cells to two bitter tastants (denatonium and caffeine) were investigated using a calcium-imaging technique and compared with the response to bombesin. Caffeine is known to stimulate taste receptor cells, but the properties of its signaling have not been well studied. STC-1 cells responded to all three molecules in a dose-dependent manner, and when a reverse transcriptase-polymerase chain reaction (RT-PCR) for denatonium receptor was performed, the product of predicted size was detected in STC-1 cells. Furthermore, all three signaling pathways were blocked by a phospholipase C (PLC) inhibitor, demonstrating the essential involvement of PLC in cellular responses. To study the regulatory system of G protein signaling in STC-1 cells, we searched G protein-coupled receptor kinases (GRKs) by the degenerate-primer PCR method and found that GRK2 is expressed. We also demonstrated that three GRKs (GRK2, GRK3 and GRK5) are differentially distributed in the circumvallate papilla while only GRK2 is present in taste bud cells. Finally, we overexpressed GRK2 in SCT-1 cells and found that bombesin-induced response was strongly inhibited by GRK2 but denatonium-activated signaling was not affected. In the case of caffeine, response was decreased by expression of GRK2 only when cells were activated by 1 mM caffeine. Thus, we showed that STC-1 cells emerge as a cell model for studying the molecular mechanism of bitter taste signaling, and could indicate properties of caffeine-induced signaling in comparison with other signaling. PMID:15741596

  11. Carbon Stocks of Tropical Coastal Wetlands within the Karstic Landscape of the Mexican Caribbean

    PubMed Central

    Adame, Maria Fernanda; Kauffman, J. Boone; Medina, Israel; Gamboa, Julieta N.; Torres, Olmo; Caamal, Juan P.; Reza, Miriam; Herrera-Silveira, Jorge A.

    2013-01-01

    Coastal wetlands can have exceptionally large carbon (C) stocks and their protection and restoration would constitute an effective mitigation strategy to climate change. Inclusion of coastal ecosystems in mitigation strategies requires quantification of carbon stocks in order to calculate emissions or sequestration through time. In this study, we quantified the ecosystem C stocks of coastal wetlands of the Sian Ka'an Biosphere Reserve (SKBR) in the Yucatan Peninsula, Mexico. We stratified the SKBR into different vegetation types (tall, medium and dwarf mangroves, and marshes), and examined relationships of environmental variables with C stocks. At nine sites within SKBR, we quantified ecosystem C stocks through measurement of above and belowground biomass, downed wood, and soil C. Additionally, we measured nitrogen (N) and phosphorus (P) from the soil and interstitial salinity. Tall mangroves had the highest C stocks (987±338 Mg ha−1) followed by medium mangroves (623±41 Mg ha−1), dwarf mangroves (381±52 Mg ha−1) and marshes (177±73 Mg ha−1). At all sites, soil C comprised the majority of the ecosystem C stocks (78–99%). Highest C stocks were measured in soils that were relatively low in salinity, high in P and low in N∶P, suggesting that P limits C sequestration and accumulation potential. In this karstic area, coastal wetlands, especially mangroves, are important C stocks. At the landscape scale, the coastal wetlands of Sian Ka'an covering ≈172,176 ha may store 43.2 to 58.0 million Mg of C. PMID:23457583

  12. Carbon stocks of tropical coastal wetlands within the karstic landscape of the Mexican Caribbean.

    PubMed

    Adame, Maria Fernanda; Kauffman, J Boone; Medina, Israel; Gamboa, Julieta N; Torres, Olmo; Caamal, Juan P; Reza, Miriam; Herrera-Silveira, Jorge A

    2013-01-01

    Coastal wetlands can have exceptionally large carbon (C) stocks and their protection and restoration would constitute an effective mitigation strategy to climate change. Inclusion of coastal ecosystems in mitigation strategies requires quantification of carbon stocks in order to calculate emissions or sequestration through time. In this study, we quantified the ecosystem C stocks of coastal wetlands of the Sian Ka'an Biosphere Reserve (SKBR) in the Yucatan Peninsula, Mexico. We stratified the SKBR into different vegetation types (tall, medium and dwarf mangroves, and marshes), and examined relationships of environmental variables with C stocks. At nine sites within SKBR, we quantified ecosystem C stocks through measurement of above and belowground biomass, downed wood, and soil C. Additionally, we measured nitrogen (N) and phosphorus (P) from the soil and interstitial salinity. Tall mangroves had the highest C stocks (987±338 Mg ha(-1)) followed by medium mangroves (623±41 Mg ha(-1)), dwarf mangroves (381±52 Mg ha(-1)) and marshes (177±73 Mg ha(-1)). At all sites, soil C comprised the majority of the ecosystem C stocks (78-99%). Highest C stocks were measured in soils that were relatively low in salinity, high in P and low in N∶P, suggesting that P limits C sequestration and accumulation potential. In this karstic area, coastal wetlands, especially mangroves, are important C stocks. At the landscape scale, the coastal wetlands of Sian Ka'an covering ≈172,176 ha may store 43.2 to 58.0 million Mg of C.

  13. Fish community structure in freshwater karstic water bodies of the Sian Ka'an Reserve in the Yucatan peninsula, Mexico

    USGS Publications Warehouse

    Zambrano, L.; Vazquez-Dominguez, E.; Garcia-Bedoya, D.; Loftus, W.F.; Trexler, J.C.

    2006-01-01

    We evaluated the relationship between limnetic characteristics and fish community structure (based on species richness, abundance and individual size) in contrasting but interconnected inland aquatic habitats of freshwater karstic wetlands in the Yucatan peninsula, Mexico. In the western hemisphere, freshwater karstic wetlands are found in south-eastern Mexico, northern Belize, western Cuba, Andros Island, Bahamas and the Everglades of southern Florida. Only in the Everglades have fish communities been well described. Karstic wetlands are typically oligotrophic because calcium carbonate binds phosphorus, making it relatively unavailable for plants. Fourteen permanent and seasonally flooded water bodies were sampled in both wet and dry seasons in Sian Ka'an Biosphere Reserve, in the Mexican state of Quintana Roo. Water systems were divided by morphology in four groups: cenotes with vegetation (CWV), cenotes without vegetation (CNV), wetlands (WTL), and temporal cenotes (TPC). Discriminant analysis based on physical characteristics such as turbidity, temperature, depth and oxygen confirmed that these habitats differed in characteristics known to influence fish communities. A sample-based rarefaction test showed that species richness was significantly different between water systems groups, showing that WTL and CWV had higher richness values than CNV and TPC. The most abundant fish families, Poeciliidae, Cichlidae and Characidae, differed significantly in average size among habitats and seasons. Seasonal and inter-annual variation, reflecting temporal variation in rainfall, strongly influenced the environmental differences between shallow and deep habitats, which could be linked to fish size and life cycles. Five new records of species were found for the reserve, and one new record for Quintana Roo state. ?? 2006 by Verlag Dr. Friedrich Pfeil.

  14. Salinity sources of Kefar Uriya wells in the Judea Group aquifer of Israel. Part 1—conceptual hydrogeological model

    NASA Astrophysics Data System (ADS)

    Avisar, D.; Rosenthal, E.; Flexer, A.; Shulman, H.; Ben-Avraham, Z.; Guttman, J.

    2003-01-01

    In the Yarkon-Taninim groundwater basin, the karstic Judea Group aquifer contains groundwater of high quality. However, in the western wells of the Kefar Uriya area located in the foothills of the Judea Mountains, brackish groundwater was locally encountered. The salinity of this water is caused presumably by two end members designated as the 'Hazerim' and 'Lakhish' water types. The Hazerim type represents surface water percolating through a highly fractured thin chalky limestone formation overlying the Judea Group aquifer. The salinity of the water derives conjointly from several sources such as leachates from rendzina and grumosols, dissolution of caliche crusts which contain evaporites and of rock debris from the surrounding formations. This surface water percolates downwards into the aquifer through a funnel- or chimney-like mechanism. This local salinization mechanism supercedes another regional process caused by the Lakhish waters. These are essentially diluted brines originating from deep formations in the western parts of the Coastal Plain. The study results show that salinization is not caused by the thick chalky beds of the Senonian Mt Scopus Group overlying the Judea Group aquifer, as traditionally considered but prevalently by aqueous leachates from soils and rock debris. The conceptual qualitative hydrogeological model of the salinization as demonstrated in this study, is supported by a quantitative hydrological model presented in another paper in this volume.

  15. Receptor Polymorphism and Genomic Structure Interact to Shape Bitter Taste Perception

    PubMed Central

    Roudnitzky, Natacha; Behrens, Maik; Engel, Anika; Kohl, Susann; Thalmann, Sophie; Hübner, Sandra; Lossow, Kristina; Wooding, Stephen P.; Meyerhof, Wolfgang

    2015-01-01

    The ability to taste bitterness evolved to safeguard most animals, including humans, against potentially toxic substances, thereby leading to food rejection. Nonetheless, bitter perception is subject to individual variations due to the presence of genetic functional polymorphisms in bitter taste receptor (TAS2R) genes, such as the long-known association between genetic polymorphisms in TAS2R38 and bitter taste perception of phenylthiocarbamide. Yet, due to overlaps in specificities across receptors, such associations with a single TAS2R locus are uncommon. Therefore, to investigate more complex associations, we examined taste responses to six structurally diverse compounds (absinthin, amarogentin, cascarillin, grosheimin, quassin, and quinine) in a sample of the Caucasian population. By sequencing all bitter receptor loci, inferring long-range haplotypes, mapping their effects on phenotype variation, and characterizing functionally causal allelic variants, we deciphered at the molecular level how a subjects’ genotype for the whole-family of TAS2R genes shapes variation in bitter taste perception. Within each haplotype block implicated in phenotypic variation, we provided evidence for at least one locus harboring functional polymorphic alleles, e.g. one locus for sensitivity to amarogentin, one of the most bitter natural compounds known, and two loci for sensitivity to grosheimin, one of the bitter compounds of artichoke. Our analyses revealed also, besides simple associations, complex associations of bitterness sensitivity across TAS2R loci. Indeed, even if several putative loci harbored both high- and low-sensitivity alleles, phenotypic variation depended on linkage between these alleles. When sensitive alleles for bitter compounds were maintained in the same linkage phase, genetically driven perceptual differences were obvious, e.g. for grosheimin. On the contrary, when sensitive alleles were in opposite phase, only weak genotype-phenotype associations were

  16. 40 CFR 147.2908 - Aquifer exemptions.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 24 2013-07-01 2013-07-01 false Aquifer exemptions. 147.2908 Section...-Class II Wells § 147.2908 Aquifer exemptions. (a) After notice and opportunity for a public hearing, the Administrator may designate any aquifer or part of an aquifer as an exempted aquifer. (b) An aquifer or...

  17. 40 CFR 147.2908 - Aquifer exemptions.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 24 2012-07-01 2012-07-01 false Aquifer exemptions. 147.2908 Section...-Class II Wells § 147.2908 Aquifer exemptions. (a) After notice and opportunity for a public hearing, the Administrator may designate any aquifer or part of an aquifer as an exempted aquifer. (b) An aquifer or...

  18. 40 CFR 147.2908 - Aquifer exemptions.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 23 2014-07-01 2014-07-01 false Aquifer exemptions. 147.2908 Section...-Class II Wells § 147.2908 Aquifer exemptions. (a) After notice and opportunity for a public hearing, the Administrator may designate any aquifer or part of an aquifer as an exempted aquifer. (b) An aquifer or...

  19. 40 CFR 147.2908 - Aquifer exemptions.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 22 2010-07-01 2010-07-01 false Aquifer exemptions. 147.2908 Section...-Class II Wells § 147.2908 Aquifer exemptions. (a) After notice and opportunity for a public hearing, the Administrator may designate any aquifer or part of an aquifer as an exempted aquifer. (b) An aquifer or...

  20. 40 CFR 147.2908 - Aquifer exemptions.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 23 2011-07-01 2011-07-01 false Aquifer exemptions. 147.2908 Section...-Class II Wells § 147.2908 Aquifer exemptions. (a) After notice and opportunity for a public hearing, the Administrator may designate any aquifer or part of an aquifer as an exempted aquifer. (b) An aquifer or...

  1. Hazard connected to tunnel construction in Mt Stena karstic area (Rosandra Valley, Classical Karst)

    NASA Astrophysics Data System (ADS)

    Cucchi, F.; Boschin, W.; Visintin, L.; Zini, L.

    2009-04-01

    Rosandra Valley -a unique geomorphological environment- is located in the western side of the Classical Karst plateau. This deep limestone gorge is crossed by a stream that is fed by a large basin located in Slovenia. Rosandra Valley is the only example of Classical Karst river valley with surface hydrography; the torrent digs a deep gully into the rock, rich in rapids, swirl holes, small waterfalls, enclosed meanders and basins; here, the first seepage phenomena occur, and part of the water feeds the underground aquifer. Rosandra Valley is theatre to complex structural situation; the NE slope culminates in the structure of Mt Stena, a limestone tectonic scale located between two faults and firmly rooted in the karst platform. Tectonics is quite important for the development of deep karst in this area; Mt Stena, in particular, hosts a comprehensive net of articulated and diversely shaped caves, basically organised on several levels, which stretches over a total of 9,000 metres, bearing testimony to ancient geological and hydrogeological origins. The deepest areas of the system reach a suspended aquifer that is probably sustained by an overthrust and placed about 100 meters above Rosandra torrent underground aquifer. During feasibility studies about Trieste-Divača high velocity railway link, interaction between project and karst features was examined; in fact the proximity of proposal project and Mt Stena karst system suggest to improve the knowledge related to karst and hydrogeological aspects of the massif. Compatibly with the project requirements, risk of voids intersection and water contamination were analyzed. In fact the Mt Stena suspended aquifer partially feeds Rosandra torrent which flows in a protected natural area. Karst features were represented in a 3D model in order to better understand the spatial relationship between railway project and karst system.

  2. Bitter tastant responses in the amoeba Dictyostelium correlate with rat and human taste assays.

    PubMed

    Cocorocchio, Marco; Ives, Robert; Clapham, David; Andrews, Paul L R; Williams, Robin S B

    2016-01-01

    Treatment compliance is reduced when pharmaceutical compounds have a bitter taste and this is particularly marked for paediatric medications. Identification of bitter taste liability during drug discovery utilises the rat in vivo brief access taste aversion (BATA) test which apart from animal use is time consuming with limited throughput. We investigated the suitability of using a simple, non-animal model, the amoeba Dictyostelium discoideum to investigate taste-related responses and particularly identification of compounds with a bitter taste liability. The effect of taste-related compounds on Dictyostelium behaviour following acute exposure (15 minutes) was monitored. Dictyostelium did not respond to salty, sour, umami or sweet tasting compounds, however, cells rapidly responded to bitter tastants. Using time-lapse photography and computer-generated quantification to monitor changes in cell membrane movement, we developed an assay to assess the response of Dictyostelium to a wide range of structurally diverse known bitter compounds and blinded compounds. Dictyostelium showed varying responses to the bitter tastants, with IC50 values providing a rank order of potency. Comparison of Dictyostelium IC50 values to those observed in response to a similar range of compounds in the rat in vivo brief access taste aversion test showed a significant (p = 0.0172) positive correlation between the two models, and additionally a similar response to that provided by a human sensory panel assessment test. These experiments demonstrate that Dictyostelium may provide a suitable model for early prediction of bitterness for novel tastants and drugs. Interestingly, a response to bitter tastants appears conserved from single-celled amoebae to humans. PMID:26708104

  3. Bitter avoidance in Guinea Pigs (Cavia porcellus) and Mice (Mus musculus and Peromyscus leucopus)

    PubMed Central

    Field, Kristin L.; Beauchamp, Gary K.; Kimball, Bruce A.; Mennella, Julie A.; Bachmanov, Alexander A.

    2010-01-01

    Rejection of bitter substances is common in many species and may function to protect an animal from ingestion of bitter-tasting toxins. Since many plants are bitter, it has been proposed that high tolerance for bitterness would be adaptive for herbivores. Earlier studies conducted on herbivorous guinea pigs (Cavia porcellus) have been used to support this proposal. We tested guinea pigs with bitter plant secondary metabolites (salicin, caffeine, quinine hydrochloride) and bitter protein hydrolysates (two types of hydrolyzed casein, hydrolyzed soy) in a series of two-choice preference tests. For comparison, we tested two non-herbivorous mouse species (Mus musculus and Peromyscus leucopus). Guinea pigs did show weaker avoidance of QHCl than did the mice, confirming predictions generated from earlier work. However, guinea pigs had similar responses to caffeine as did Peromyscus. Both of these species showed weaker avoidance responses than Mus to 10 mM caffeine. For salicin, guinea pigs were the only species to avoid it at 10 mM and their preference scores at this concentration were significantly lower than for the two mice species. Guinea pigs avoided all of the protein hydrolysates more strongly than the other species. Responses to the protein hydrolysates did not reflect the patterns observed with the simple bitter compounds, suggesting that other properties of these complex stimuli may be responsible for guinea pig avoidance of them. Our results suggest caution in accepting, without further empirical support, the premise that guinea pigs (and herbivores in general) have a generalized reduced bitter sensitivity. PMID:21090891

  4. Bitter tastant responses in the amoeba Dictyostelium correlate with rat and human taste assays.

    PubMed

    Cocorocchio, Marco; Ives, Robert; Clapham, David; Andrews, Paul L R; Williams, Robin S B

    2016-01-01

    Treatment compliance is reduced when pharmaceutical compounds have a bitter taste and this is particularly marked for paediatric medications. Identification of bitter taste liability during drug discovery utilises the rat in vivo brief access taste aversion (BATA) test which apart from animal use is time consuming with limited throughput. We investigated the suitability of using a simple, non-animal model, the amoeba Dictyostelium discoideum to investigate taste-related responses and particularly identification of compounds with a bitter taste liability. The effect of taste-related compounds on Dictyostelium behaviour following acute exposure (15 minutes) was monitored. Dictyostelium did not respond to salty, sour, umami or sweet tasting compounds, however, cells rapidly responded to bitter tastants. Using time-lapse photography and computer-generated quantification to monitor changes in cell membrane movement, we developed an assay to assess the response of Dictyostelium to a wide range of structurally diverse known bitter compounds and blinded compounds. Dictyostelium showed varying responses to the bitter tastants, with IC50 values providing a rank order of potency. Comparison of Dictyostelium IC50 values to those observed in response to a similar range of compounds in the rat in vivo brief access taste aversion test showed a significant (p = 0.0172) positive correlation between the two models, and additionally a similar response to that provided by a human sensory panel assessment test. These experiments demonstrate that Dictyostelium may provide a suitable model for early prediction of bitterness for novel tastants and drugs. Interestingly, a response to bitter tastants appears conserved from single-celled amoebae to humans.

  5. Modification of ginseng flavors by bitter compounds found in chocolate and coffee.

    PubMed

    Sook Chung, Hee; Lee, Soo-Yeun

    2012-06-01

    Ginseng is not widely accepted by U.S. consumers due to its unfamiliar flavors, despite its numerous health benefits. Previous studies have suggested that the bitter compounds in chocolate and coffee may mask the off-flavors of ginseng. The objectives of this study were to: (1) profile sensory characteristics of ginseng extract solution, caffeine solution, cyclo (L-Pro-L-Val) solution, theobromine solution, and 2 model solutions simulating chocolate bitterness; and (2) determine the changes in the sensory characteristics of ginseng extract solution by the addition of the bitter compounds found in chocolate and coffee. Thirteen solutions were prepared in concentrations similar to the levels of the bitter compounds found in coffee and chocolate products. Twelve panelists participated in a descriptive analysis panel which included time-intensity ratings. Ginseng extract was characterized as sweeter, starchier, and more green tea than the other sample solutions. Those characteristics of ginseng extract were effectively modified by the addition of caffeine, cyclo (L-Pro-L-Val), and 2 model solutions. A model solution simulating dark chocolate bitterness was the least influenced in intensities of bitterness by the addition of ginseng extract. Results from time-intensity ratings show that the addition of ginseng extract increased duration time in certain bitterness of the 2 model solutions. Bitter compounds found in dark chocolate could be proposed to effectively mask the unique flavors of ginseng. Future studies blending aroma compounds of chocolate and coffee into such model solutions may be conducted to investigate the influence on the perception of the unique flavors through the congruent flavors.

  6. Inhibitory effect of aroma on the bitterness of branched-chain amino acid solutions.

    PubMed

    Mukai, Junji; Tokuyama, Emi; Ishizaka, Toshihiko; Okada, Sachie; Uchida, Takahiro

    2007-11-01

    Nutritional products for patients with liver failure available on the Japanese market contain many branched-chain amino acids (BCAAs) such as L-leucine, L-isoleucine, and L-valine, which not only have a bitter taste but also strong, unpleasant odours, leading to low palatability. The palatability of these nutritional products can be significantly improved by the addition of flavoured powders containing various kinds of tastants (sucrose, citric acid, etc.) and odourants (fruit, coffee aromas, etc.). The specific effects of the aroma of flavoured powders have not yet been clearly evaluated. In the present article, the inhibitory effect of aroma on the bitterness of BCAA solutions was examined. The bitterness intensity of a BCAA solution at the same concentration as Aminoleban EN was defined as 3.5 (measured by a previously described gustatory sensation method). The bitterness threshold of a BCAA standard solution without added aroma was estimated to be 1.87, while those of BCAA solutions containing green-tea, coffee, apple, vanilla, or strawberry aromas were 2.02, 1.98, 2.35, 2.40 and 2.87, respectively, when evaluated by the probit method. This shows that the addition of an aroma can elevate the bitterness threshold in human volunteers. The green-tea and coffee aromas predominantly evoked bitterness, while the vanilla aroma predominantly evoked sweetness. Apple and strawberry aromas evoked both sweetness and sourness, with the apple aroma having stronger sourness and the strawberry aroma stronger sweetness. Thus, a 'sweet' aroma suppresses the bitterness of BCAA, with coexisting sourness also participating in the bitterness inhibition.

  7. Evolution of Functionally Diverse Alleles Associated with PTC Bitter Taste Sensitivity in Africa

    PubMed Central

    Campbell, Michael C.; Ranciaro, Alessia; Froment, Alain; Hirbo, Jibril; Omar, Sabah; Bodo, Jean-Marie; Nyambo, Thomas; Lema, Godfrey; Zinshteyn, Daniel; Drayna, Dennis; Breslin, Paul A. S.; Tishkoff, Sarah A.

    2012-01-01

    Although human bitter taste perception is hypothesized to be a dietary adaptation, little is known about genetic signatures of selection and patterns of bitter taste perception variability in ethnically diverse populations with different diets, particularly from Africa. To better understand the genetic basis and evolutionary history of bitter taste sensitivity, we sequenced a 2,975 bp region encompassing TAS2R38, a bitter taste receptor gene, in 611 Africans from 57 populations in West Central and East Africa with diverse subsistence patterns, as well as in a comparative sample of 132 non-Africans. We also examined the association between genetic variability at this locus and threshold levels of phenylthiocarbamide (PTC) bitterness in 463 Africans from the above populations to determine how variation influences bitter taste perception. Here, we report striking patterns of variation at TAS2R38, including a significant excess of novel rare nonsynonymous polymorphisms that recently arose only in Africa, high frequencies of haplotypes in Africa associated with intermediate bitter taste sensitivity, a remarkably similar frequency of common haplotypes across genetically and culturally distinct Africans, and an ancient coalescence time of common variation in global populations. Additionally, several of the rare nonsynonymous substitutions significantly modified levels of PTC bitter taste sensitivity in diverse Africans. While ancient balancing selection likely maintained common haplotype variation across global populations, we suggest that recent selection pressures may have also resulted in the unusually high level of rare nonsynonymous variants in Africa, implying a complex model of selection at the TAS2R38 locus in African populations. Furthermore, the distribution of common haplotypes in Africa is not correlated with diet, raising the possibility that common variation may be under selection due to their role in nondietary biological processes. In addition, our data

  8. Sources and processes affecting sulfate in a karstic groundwater system of the Franconian Alb, southern Germany.

    PubMed

    Einsiedl, Florian; Mayer, Bernhard

    2005-09-15

    Chemical and isotope analyses on groundwater sulfate and 3H measurements on groundwaterwere used to determine the sulfate sources and sulfur transformation processes in a heterogeneous karst aquifer of the Franconian Alb, southern Germany. Sulfate was found to be derived from atmospheric deposition. Young groundwater was characterized by high sulfate concentrations and delta34S values similar to those of recent atmospheric sulfate deposition. However, the delta18O values of groundwater SO4(2-) were depleted by several per mil with respect to those of atmospheric deposition. This isotopic shift is indicative of mineralization of carbon-bonded S in the vadose zone of the karst system. In groundwater with mean residence times of more than 60 years, a trend of increasing delta34S values and delta18O values with decreasing sulfate concentrations was observed. This trend could not be solely explained by preindustrial atmospheric sulfate deposition with higher delta34S values, and hence, we conclude that bacterial (dissimilatory) sulfate reduction in the porous matrix of the karst aquifer must have occurred. This process has the potential to contribute to long-term biodegradation of contaminants in the porous rock matrix representing the dominantwater reservoir of the fissured porous karst aquifer.

  9. Interpretation of well hydrographs in the karstic Maynardville Limestone at the Oak Ridge Y-12 Plant

    SciTech Connect

    Shevenell, L.A.; McMaster, B.W.

    1996-06-01

    The Maynardville Limestone in Oak Ridge, Tennessee underlies the southern portion of Bear Creek Valley (BCV), and is considered to be the primary pathway for groundwater leaving the Y-12 Plant boundaries. Sixty-seven percent of all wells drilled into the Maynardville Limestone have intersected at least one cavity, suggesting karst features may be encountered throughout the shallow (< 200 ft) portions of the Limestone. Because waste facilities at the Y-12 Plant are located adjacent to the Maynardville Limestone, contaminants could enter the karst aquifer and be transported in the conduit system. As part of an overall hydrologic characterization effort of this karst aquifer, 41 wells in the Maynardville Limestone were instrumented with pressure transducers to monitor water level changes (hydrographs) associated with rain events. Wells at depths between approximately 20 and 750 ft were monitored over the course of at least two storms in order that variations with depth could be identified. The wells selected were not exclusively completed in cavities but were selected to include the broad range of hydrologic conditions present in the Maynardville Limestone. Cavities, fractures and diffuse flow zones were measured at a variety of depths. The water level data from the storms are used to identify areas of quickflow versus slower flowing water zones. The data are also used to estimate specific yields and continuum transmissitives in different portions of the aquifer.

  10. Cold water aquifer storage

    NASA Astrophysics Data System (ADS)

    Reddell, D. L.; Davison, R. R.; Harris, W. B.

    1980-03-01

    A working prototype system is described in which water is pumped from an aquifer at 70 F in the winter time, chilled to a temperature of less than 50 F, injected into a ground-water aquifer, stored for a period of several months, pumped back to the surface in the summer time. A total of 8.1 million gallons of chilled water at an average temperature of 48 F were injected. This was followed by a storage period of 100 days. The recovery cycle was completed a year later with a total of 8.1 million gallons recovered. Approximately 20 percent of the chill energy was recovered.

  11. Covariation in individuals' sensitivities to bitter compounds: evidence supporting multiple receptor/transduction mechanisms.

    PubMed

    Delwiche, J F; Buletic, Z; Breslin, P A

    2001-07-01

    People vary widely in their sensitivities to bitter compounds, but the intercorrelation of these sensitivities is unknown. Our goal was to investigate correlations as a function of individual sensitivities to several bitter compounds representative of different chemical classes and, from these correlations, infer the number and variety of potential bitterness transduction systems for these compounds. Twenty-six subjects rated and ranked quinine HCl, caffeine, (-)-epicatechin, tetralone, L-phenylalanine, L-tryptophan, magnesium sulfate, urea, sucrose octaacetate (SOA), denatonium benzoate, and n-propylthiouracil (PROP) for bitterness. By examining individual differences, ratings and rankings could be grouped into two general clusters--urea/phenylalanine/tryptophan/epicatechin, and quinine/caffeine/SOA/denatonium benzoate/tetralone/magnesium sulfate-none of which contained PROP. When subjects were grouped into the extremes of sensitivity to PROP, a significant difference was found in the bitterness ratings, but not in the rankings. Therefore, there are also subjects who possess diminished absolute sensitivity to bitter stimuli but do not differ from other subjects in their relative sensitivities to these compounds. PMID:11521845

  12. 6-Methoxyflavanones as Bitter Taste Receptor Blockers for hTAS2R39

    PubMed Central

    Roland, Wibke S. U.; Gouka, Robin J.; Gruppen, Harry; Driesse, Marianne; van Buren, Leo; Smit, Gerrit; Vincken, Jean-Paul

    2014-01-01

    Many (dietary) bitter compounds, e.g. flavonoids, activate bitter receptor hTAS2R39 in cell-based assays. Several flavonoids, amongst which some flavanones, are known not to activate this receptor. As certain flavanones are known to mask bitter taste sensorially, flavanones might act as bitter receptor antagonists. Fourteen flavanones were investigated for their potential to reduce activation of hTAS2R39 by epicatechin gallate (ECG), one of the main bitter compounds occurring in green tea. Three flavanones showed inhibitory behavior towards the activation of hTAS2R39 by ECG: 4′-fluoro-6-methoxyflavanone, 6,3′-dimethoxyflavanone, and 6-methoxyflavanone (in order of decreasing potency). The 6-methoxyflavanones also inhibited activation of hTAS2R14 (another bitter receptor activated by ECG), though to a lesser extent. Dose-response curves of ECG at various concentrations of the full antagonist 4′-fluoro-6-methoxyflavanone and wash-out experiments indicated reversible insurmountable antagonism. The same effect was observed for the structurally different agonist denatonium benzoate. PMID:24722342

  13. Nasal solitary chemoreceptor cell responses to bitter and trigeminal stimulants in vitro

    PubMed Central

    Gulbransen, Brian D; Clapp, Tod R; Kinnamon, Sue C; Finger, Thomas E

    2009-01-01

    Nasal trigeminal chemosensitivity in mice and rats is mediated in part by epithelial solitary chemoreceptor (chemosensory) cells (SCCs), but the exact role of these cells in chemoreception is unclear (Finger et al. 2003). Histological evidence suggests that SCCs express elements of the bitter taste transduction pathway including T2R (bitter taste) receptors, the G protein α-gustducin, PLCβ2, and TRPM5, leading to speculation that SCCs are the receptor cells that mediate trigeminal nerve responses to bitter taste receptor ligands. To test this hypothesis, we used calcium imaging to determine whether SCCs respond to classic bitter-tasting or trigeminal stimulants. SCCs from the anterior nasal cavity were isolated from transgenic mice in which green fluorescent protein (GFP) expression was driven by either TRPM5 or gustducin. Isolated cells were exposed to a variety of test stimuli to determine which substances caused an increase in intracellular Ca2+ ([Ca2+]i). GFP positive cells respond with increased [Ca2+]i to the bitter receptor ligand denatonium, and this response is blocked by the PLC inhibitor U73122. In addition GFP+ cells respond to the PLC activator 3M3FBS, the neuromodulators ATP and ACh, but only very rarely to other bitter-tasting or trigeminal stimuli. Our results demonstrate that TRPM5- and gustducin-expressing nasal SCCs respond to the T2R agonist, denatonium via a PLC-coupled transduction cascade typical of T2Rs in the taste system. PMID:18417634

  14. Vampire bats exhibit evolutionary reduction of bitter taste receptor genes common to other bats.

    PubMed

    Hong, Wei; Zhao, Huabin

    2014-08-01

    The bitter taste serves as an important natural defence against the ingestion of poisonous foods and is thus believed to be indispensable in animals. However, vampire bats are obligate blood feeders that show a reduced behavioural response towards bitter-tasting compounds. To test whether bitter taste receptor genes (T2Rs) have been relaxed from selective constraint in vampire bats, we sampled all three vampire bat species and 11 non-vampire bats, and sequenced nine one-to-one orthologous T2Rs that are assumed to be functionally conserved in all bats. We generated 85 T2R sequences and found that vampire bats have a significantly greater percentage of pseudogenes than other bats. These results strongly suggest a relaxation of selective constraint and a reduction of bitter taste function in vampire bats. We also found that vampire bats retain many intact T2Rs, and that the taste signalling pathway gene Calhm1 remains complete and intact with strong functional constraint. These results suggest the presence of some bitter taste function in vampire bats, although it is not likely to play a major role in food selection. Together, our study suggests that the evolutionary reduction of bitter taste function in animals is more pervasive than previously believed, and highlights the importance of extra-oral functions of taste receptor genes.

  15. Age modifies the genotype-phenotype relationship for the bitter receptor TAS2R38

    PubMed Central

    2010-01-01

    Background The purpose of this study was to investigate the effect of TAS2R38 haplotypes and age on human bitter taste perception. Results Children (3 to 10 yrs), adolescents (11 to 19 yrs) and adults (mostly mothers, 20 to 55 yrs (N = 980) were measured for bitter taste thresholds for 6-n-propylthiouracil (PROP) and genotyped for three polymorphisms of the AS2R38 gene (A49P, V262A, I296V). Subjects were grouped by haplotype and age, as well as sex and race/ethnicity, and compared for PROP thresholds. Subjects with the same haplotype were similar in bitter threshold regardless of race/ethnicity (all ages) or sex (children and adolescents; all p-values > 0.05) but age was a modifier of the genotype-phenotype relationship. Specifically, AVI/PAV heterozygous children could perceive a bitter taste at lower PROP concentrations than could heterozygous adults, with the thresholds of heterozygous adolescents being intermediate (p < 0.001). Similar age effects were not observed for subjects with the PAV/PAV or AVI/AVI homozygous haplotypes (p > 0.05) perhaps because there is less variation in taste perception among these homozygotes. Conclusions These data imply that the change in PROP bitter sensitivity which occurs over the lifespan (from bitter sensitive to less so) is more common in people with a particular haplotype combination, i.e., AVI/PAV heterozygotes. PMID:20594349

  16. Quinine Bitterness and Grapefruit Liking Associate with Allelic Variants in TAS2R31.

    PubMed

    Hayes, John E; Feeney, Emma L; Nolden, Alissa A; McGeary, John E

    2015-07-01

    Multiple psychophysical gene-association studies suggest a single nucleotide polymorphism (SNP) within the bitter receptor gene TAS2R19 on chromosome 12 may be functional. Previously, the Arg299Cys SNP (rs10772420) has been associated with differential bitterness of quinine and differential liking for grapefruit juice. However, quinine does not activate TAS2R19 in vitro; likewise, limonin and naringin, bitter compounds in grapefruit, do not activate TAS2R19 in vitro. Here, we examined quinine bitterness (whole-mouth swish-and-spit stimuli and regionally delivered quinine across 4 loci) and remembered liking for grapefruit juice to test whether they associate with SNPs in another nearby gene, TASR2R31. We observed SNP-phenotype associations between whole-mouth quinine bitterness and self-reported liking for grapefruit juice with SNPs in TAS2R31, and regional quinine bitterness followed a similar trend, but did not reach significance. Present data provide independent replication of prior associations reported for TAS2R19. However, we also observed strong linkage disequilibrium (LD) between TAS2R19 and TAS2R31 SNPs. When present data are considered in light of existing functional expression data, this suggests phenotypic associations reported previously for rs10772420 may potentially be due to LD between this SNP and polymorphism(s) in, or closer to, TAS2R31. If confirmed, this would reduce the number of TAS2Rs with putatively functional polymorphisms to 5.

  17. Quinine Bitterness and Grapefruit Liking Associate with Allelic Variants in TAS2R31

    PubMed Central

    Feeney, Emma L.; Nolden, Alissa A.; McGeary, John E.

    2015-01-01

    Multiple psychophysical gene-association studies suggest a single nucleotide polymorphism (SNP) within the bitter receptor gene TAS2R19 on chromosome 12 may be functional. Previously, the Arg299Cys SNP (rs10772420) has been associated with differential bitterness of quinine and differential liking for grapefruit juice. However, quinine does not activate TAS2R19 in vitro; likewise, limonin and naringin, bitter compounds in grapefruit, do not activate TAS2R19 in vitro. Here, we examined quinine bitterness (whole-mouth swish-and-spit stimuli and regionally delivered quinine across 4 loci) and remembered liking for grapefruit juice to test whether they associate with SNPs in another nearby gene, TASR2R31. We observed SNP–phenotype associations between whole-mouth quinine bitterness and self-reported liking for grapefruit juice with SNPs in TAS2R31, and regional quinine bitterness followed a similar trend, but did not reach significance. Present data provide independent replication of prior associations reported for TAS2R19. However, we also observed strong linkage disequilibrium (LD) between TAS2R19 and TAS2R31 SNPs. When present data are considered in light of existing functional expression data, this suggests phenotypic associations reported previously for rs10772420 may potentially be due to LD between this SNP and polymorphism(s) in, or closer to, TAS2R31. If confirmed, this would reduce the number of TAS2Rs with putatively functional polymorphisms to 5. PMID:26024668

  18. Vampire bats exhibit evolutionary reduction of bitter taste receptor genes common to other bats.

    PubMed

    Hong, Wei; Zhao, Huabin

    2014-08-01

    The bitter taste serves as an important natural defence against the ingestion of poisonous foods and is thus believed to be indispensable in animals. However, vampire bats are obligate blood feeders that show a reduced behavioural response towards bitter-tasting compounds. To test whether bitter taste receptor genes (T2Rs) have been relaxed from selective constraint in vampire bats, we sampled all three vampire bat species and 11 non-vampire bats, and sequenced nine one-to-one orthologous T2Rs that are assumed to be functionally conserved in all bats. We generated 85 T2R sequences and found that vampire bats have a significantly greater percentage of pseudogenes than other bats. These results strongly suggest a relaxation of selective constraint and a reduction of bitter taste function in vampire bats. We also found that vampire bats retain many intact T2Rs, and that the taste signalling pathway gene Calhm1 remains complete and intact with strong functional constraint. These results suggest the presence of some bitter taste function in vampire bats, although it is not likely to play a major role in food selection. Together, our study suggests that the evolutionary reduction of bitter taste function in animals is more pervasive than previously believed, and highlights the importance of extra-oral functions of taste receptor genes. PMID:24966321

  19. Assessment of bitter taste of pharmaceuticals with multisensor system employing 3 way PLS regression.

    PubMed

    Rudnitskaya, Alisa; Kirsanov, Dmitry; Blinova, Yulia; Legin, Evgeny; Seleznev, Boris; Clapham, David; Ives, Robert S; Saunders, Kenneth A; Legin, Andrey

    2013-04-01

    The application of the potentiometric multisensor system (electronic tongue, ET) for quantification of the bitter taste of structurally diverse active pharmaceutical ingredients (API) is reported. The measurements were performed using a set of bitter substances that had been assessed by a professional human sensory panel and the in vivo rat brief access taste aversion (BATA) model to produce bitterness intensity scores for each substance at different concentrations. The set consisted of eight substances, both inorganic and organic - azelastine, caffeine, chlorhexidine, potassium nitrate, naratriptan, paracetamol, quinine, and sumatriptan. With the aim of enhancing the response of the sensors to the studied APIs, measurements were carried out at different pH levels ranging from 2 to 10, thus promoting ionization of the compounds. This experiment yielded a 3 way data array (samples×sensors×pH levels) from which 3wayPLS regression models were constructed with both human panel and rat model reference data. These models revealed that artificial assessment of bitter taste with ET in the chosen set of API's is possible with average relative errors of 16% in terms of human panel bitterness score and 25% in terms of inhibition values from in vivo rat model data. Furthermore, these 3wayPLS models were applied for prediction of the bitterness in blind test samples of a further set of API's. The results of the prediction were compared with the inhibition values obtained from the in vivo rat model. PMID:23498685

  20. Quinine Bitterness and Grapefruit Liking Associate with Allelic Variants in TAS2R31.

    PubMed

    Hayes, John E; Feeney, Emma L; Nolden, Alissa A; McGeary, John E

    2015-07-01

    Multiple psychophysical gene-association studies suggest a single nucleotide polymorphism (SNP) within the bitter receptor gene TAS2R19 on chromosome 12 may be functional. Previously, the Arg299Cys SNP (rs10772420) has been associated with differential bitterness of quinine and differential liking for grapefruit juice. However, quinine does not activate TAS2R19 in vitro; likewise, limonin and naringin, bitter compounds in grapefruit, do not activate TAS2R19 in vitro. Here, we examined quinine bitterness (whole-mouth swish-and-spit stimuli and regionally delivered quinine across 4 loci) and remembered liking for grapefruit juice to test whether they associate with SNPs in another nearby gene, TASR2R31. We observed SNP-phenotype associations between whole-mouth quinine bitterness and self-reported liking for grapefruit juice with SNPs in TAS2R31, and regional quinine bitterness followed a similar trend, but did not reach significance. Present data provide independent replication of prior associations reported for TAS2R19. However, we also observed strong linkage disequilibrium (LD) between TAS2R19 and TAS2R31 SNPs. When present data are considered in light of existing functional expression data, this suggests phenotypic associations reported previously for rs10772420 may potentially be due to LD between this SNP and polymorphism(s) in, or closer to, TAS2R31. If confirmed, this would reduce the number of TAS2Rs with putatively functional polymorphisms to 5. PMID:26024668

  1. Quantitative evaluation of the bitterness of commercial medicines using a taste sensor.

    PubMed

    Uchida, T; Miyanaga, Y; Tanaka, H; Wada, K; Kurosaki, S; Ohki, T; Yoshida, M; Matsuyama, K

    2000-11-01

    The bitterness of 11 commercial medicines was evaluated both by a multichannel taste sensor and in human gustatory sensation tests with 15 volunteers. For basic drugs with amino groups in the molecule, such as quinine, there was a comparatively strong relative response electric potential (mV) of channels 1 or 2, those containing negatively charged membranes and the bitterness determined by human gustatory sensation tests. The suppression of the bitterness of quinine by sucrose and aspartame could be quantified using the artificial taste sensor and the results concurred with those from gustatory sensation tests. The usefulness of the sensor was thus confirmed for this type of compound. Anionic drugs, such as diclofenac sodium or salicylic acid gave rise in a negative response electric potential in channels 5 or 6, those containing positively charged membrane, seemed to be useful information even though their tastes are being sour rather than bitter. For drugs with both an amino (cationic) group and carboxylic acid (anionic) group in the molecule, such as theophylline, caffeine, and metronidazole, the relative response electric potential (mV) of channels containing negatively charged membranes was not increased, even though bitterness was observed in human gustatory sensation tests. Therefore, a different design of membrane component is required for more general evaluation of the bitterness of various medicines.

  2. Perception of bitterness, sweetness and liking of different genotypes of lettuce.

    PubMed

    Chadwick, M; Gawthrop, F; Michelmore, R W; Wagstaff, C; Methven, L

    2016-04-15

    Lettuce is an important leafy vegetable, consumed across the world, containing bitter sesquiterpenoid lactone (SL) compounds that may negatively affect consumer acceptance and consumption. We assessed liking of samples with differing absolute abundance and different ratios of bitter:sweet compounds by analysing recombinant inbred lines (RILs) from an interspecific lettuce mapping population derived from a cross between a wild (L. serriola acc. UC96US23) and domesticated lettuce (L. sativa, cv. Salinas). We found that the ratio of bitter:sweet compounds was a key determinant of bitterness perception and liking. We were able to demonstrate that SLs, such as 8-deoxylactucin-15-sulphate, contribute most strongly to bitterness perception, whilst 15-p-hydroxylphenylacetyllactucin-8-sulphate does not contribute to bitter taste. Glucose was the sugar most highly correlated with sweetness perception. There is a genetic basis to the biochemical composition of lettuce. This information will be useful in lettuce breeding programmes in order to produce leaves with more favourable taste profiles.

  3. Assessment of natural recharges of the Plio-Plistocene shallow aquifer system in Al Uja area /Lower Jordan Valley / Occupied Palestinian Territories

    NASA Astrophysics Data System (ADS)

    Manasra, Kayan; Marei, Amer; Sbiah, Mohamed; Uter, Hussam; Abu Thaher, Ayman

    2013-04-01

    Al Uja area locates in the Lower Jordan Valley/West Bank at 250 m below sea level. The availability of ground water, fertile soil, and warm climate during winter months make it remarkable for its agricultural activities where 600 hectares are under irrigation. Al Uja karstic spring that drain water from the Mountain carbonate aquifer system with a discharge rate between 0.5 and 8 MCM/a , and nine groundwater boreholes that tape water from the shallow Plio-Plistocene aquifer system, with an annual abstraction of 3.5 MCM are the water sources. The south-north fault system of the Jordan Rift Valley separates the two aquifer system. The shallow aquifer system locates to the east of the fault, where the Mountain aquifer system locates to the west. The Mountain aquifer consists of high fractured and karstified limestone and dolomite of Upper Cretaceous age, and the shallow aquifer system consists of gravel, sand, silt, and clay layers of the Dead Sea group. Groundwater recharge of the Mountain aquifer system takes place in the highland area in the West with an annual precipitation of about 550 mm. Formations of the shallow aquifer system crop out in the Jordan Valley where rainfall does not exceed 250 mm/a . Due to the high evaporation rate, direct recharge is neglected. Only small portion of flooding water about 0.4MCM/a infiltrate through wadi Al Uja drainage system in to the Alluvial deposits to the shallow aquifer system. In the other hand, and since more than 40 years, the nine groundwater boreholes are taping about 3 MCM/a, water table decline of about 5 m. Currently, water table locates between -290 m in the west and decrease to - 311 m in the east. Groundwater flows from the Mountain aquifer in the west to the Shallow aquifer in the east through the major fault system. The permeability of the Mountain carbonate layers is 2.49E-1 m/min and decrease to 1.6 E-2 m/min in the layers of the Shallow aquifer system, this decrease of Kf-value east wards cause a semi

  4. Hazard connected to railway tunnel construction in karstic area: applied geomorphological and hydrogeological surveys

    NASA Astrophysics Data System (ADS)

    Casagrande, G.; Cucchi, F.; Zini, L.

    2005-02-01

    In a mature karstic system, the realisation of galleries using the methodology of railway tunnel boring machine (TBM) involves particular problems due to the high risk of interference with groundwater (often subject to remarkable level variations) and with cavities and/or thick fill deposits. In order to define groundwater features it is necessary to investigate both hydrodynamic and karstification. To define and quantify the karst phenomenon in the epikarst of the Trieste Karst (Italy), an applied geomorphological approach has been experimented with surface and cavity surveys. The surface surveys have contributed to determining the potential karst versus the different outcropping lithologies and to define the structural setting of the rocky mass also through the realisation of geostructural stations and the survey of the main lines thanks to photo-interpretation. Moreover, all the dolines and the cavities present in the area interested by the gallery have been studied by analysing the probable extension of caves and/or of the secondary fill deposits and by evaluating the different genetic models. In an area 900m large and 27km long, which has been studied because of the underground karst, there are 41 dolines having diameters superior to 100m and 93 dolines whose diameters range between 100 and 50m; the dolines whose diameters are inferior to 50m are 282. The entrances of known and registered cavities in the cadastre records are 520. The hypogeal surveys have shown 5 typologies in which it has been possible to group all the cavities present in a hypothetical intersection with the excavation. The comparison between surface and hypogeal structural data and the direction of development of cavities has allowed for the definition of highly karstified discontinuity families, thus having a higher risk. The comparison of the collected data has enabled to identify the lithologies and areas having major risk and thus to quantify the probability of intersection with the

  5. [Ichthyofauna of karstic wetlands under anthropic impact: the "petenes" of Campeche, Mexico].

    PubMed

    Torres-Castro, Ivette Liliana; Vega-Cendejas, María Eugenia; Schmitter-Soto, Juan Jacobo; Palacio-Aponte, Gerardo; Rodiles-Hernández, Rocío

    2009-01-01

    "Petenes" are small springs and associated streams that drain into wetlands near the coast in karstic areas. We studied composition, distribution, and abundance of the ichthyofauna in Los Petenes region (northwest Campeche). Two petenes displaying different degrees and types of anthropic impact were selected, Hampolol and El Remate. Hampolol has a smaller area but a longer derived stream; it is located within a protected area, but has been invaded by tilapia. El Remate is a popular spa, with no tilapia; it has a larger area but a shorter derived stream. At each "petén", several sites in the main spring, the associated stream, and secondary (temporary) springs were sampled in the rainy and dry seasons. Fishing gear was variable (throw net, gill net, small and large seine nets), but effort was uniform. We recorded temperature, dissolved oxygen, salinity, and depth at each site and season; also, we noted the different types and intensities of anthropic impact (channelization, presence of exotic species, recreational use, etc.) at each petén. We compared the petenes in terms of their environmental quality and fish fauna (composition, distribution, abundance, biomass); we also tested for effects of season and site within each petén. The study found 27 species of fishes, included in 18 genera and eight families, 24 species in Hampolol and 20 in El Remate. The geographical range of 'Cichlasoma' salvini, Rivulus tenuis, Phallichthys fairweatheri, Xiphophorus hellerii, and X maculatus is extended. The dominant species in both seasons was Astyanax (probable hybrids A. aeneus x altior at Hampolol, pure A. altior at El Remate), which contributed most of the abundance and biomass, together with Vieja synspila and Poecilia velifera. A significantly greater overall diversity (H'n=3.31) was recorded in Hampolol compared to El Remate (H'n=2.10). Cluster analysis of sites by species presence allowed distinction of two groupings within each petén: permanent waters (i.e., main

  6. Volatile fraction of lavender and bitter fennel infusion extracts.

    PubMed

    Tschiggerl, Christine; Bucar, Franz

    2010-09-01

    The relative proportions of chemical classes (hydrocarbons, oxides, alcohols/ethers, aldehydes/ketones, acids/esters/lactones) in the essential oil of lavender (Lavendula angustifolia Mill., family Lamiaceae) and bitter fennel (Foeniculum vulgare Mill. subsp. vulgare var. vulgare (Mill.) Thellung, family Apiaceae) and in the volatile fraction of infusion extracts were examined and showed remarkable differences. The volatile compounds of infusions were isolated by hydrodistillation and solid phase extraction (SPE). Their qualitative and semiquantitative compositions were compared with the essential oil isolated by hydrodistillation directly from the plant material and analyzed by GC-MS. Furthermore, quantification of the major constituents of lavender oil and of the volatile fraction obtained by hydrodistillation of the infusion was performed. Comparison of the total essential oil yield quantified by hydrodistillation of the lavender infusion (0.7% v/w, corresponding to plant material) with the essential oil yield of the blossoms (5.1% v/w) revealed that only 13.9% of the initial oil could be extracted by infusion. The main constituents of the volatile fraction of the lavender infusion were (hydrodistillation/SPE): linalool (39.3%/28.2%), 1,8 cineole (24.8%/18.9%), cis-linalool oxide (furanoid) (5.8%/8.0%), trans-linalool oxide (furanoid) (4.1%/7.1%), camphor (5.3%/4.0%) and alpha-terpineol (4.0%/3.0%). The major constituents of lavender essential oil were linalool (28.8%), 1,8-cineole (18.05%), linalyl acetate (13.9%) and alpha-terpineol (4.0%). Most intriguing, in the volatile fraction of lavender infusion a significant proportional decrease of linalyl acetate and an increase of linalool oxides was recognized. The essential oil yield of fennel fruits was 12.5% v/w, whereas 1.8% v/w volatile fraction (corresponding to plant material) was obtained by hydrodistillation of the fennel infusion, which is equivalent to 14.5% of the initial fennel essential oil. The main

  7. Inquiry and Aquifers.

    ERIC Educational Resources Information Center

    Leuenberger, Ted; Shepardson, Daniel; Harbor, Jon; Bell, Cheryl; Meyer, Jason; Klagges, Hope; Burgess, Willie

    2001-01-01

    Presents inquiry-oriented activities that acquaint students with groundwater sources, movement of water through aquifers, and contamination of groundwater by pollution. In one activity, students use well log data from web-based resources to explore groundwater systems. Provides sample well log data for those not having access to local information.…

  8. Boise Geothermal Aquifer Study

    SciTech Connect

    Not Available

    1990-01-01

    This report is the final product of a detailed review and quantitative evaluation of existing data for the Boise Front Geothermal Aquifer. Upon review of the many publications, and raw data for the Boise geothermal aquifer, it became clear that adequate data only exists for analysis of current and proposed development within a limited area. This region extends approximately 1.5 miles southeast of the State Capitol to 0.5 mile northwest. Though there are geothermal wells located along the Boise Front outside of this area, the lack of production and water level data preclude any detailed discussions and analysis of their relationship to the central resource. As a result, discussion will concentrate on major users such as the Capitol Mall (CM) Boise Geothermal LTD. (BGL), Veterans Administration (VA) and Boise Warm Springs Water District (BWSWD). The objectives of this study are: Define the inter-relationship of the existing wells and/or portions of the geothermal aquifer; evaluate the effects of current and proposed development on the geothermal aquifer; estimate longevity of the geothermal resource; and make recommendations for an on-going monitoring program. 44 refs., 40 figs., 9 tabs.

  9. An environmental tracers approach to characterize groundwater recharge within a carbonate coastal aquifer (Corse-du-Sud, France)

    NASA Astrophysics Data System (ADS)

    Garel, Emilie; Huneau, Frederic; Khoumeri, Beatrice; Travi, Yves

    2013-04-01

    Bonifacio is a coastal city, highly touristic, located in the southest part of Corsica Island. One million people visit the city in July and August, whereas 3000 inhabitants live throughout the year. Bonifacio lies on a small limestone plateau with a potential aquifer poorly understood. Actually there is a strong need to characterize the hydrogeological behavior for the reason that the economic development of the region is highly dependent of the groundwater supply potential. The Miocene sedimentary basin of Bonifacio has an area of 25 km2 with a depth up to 250 m in the center. It is based and surrounded by a Hercynian granitic substratum. The basin is open to the Mediterranean Sea on its south and east sides. The formation is calcareous-sandstone and is divided in 3 sedimentary units. The upper unit is highly calcareous and sandstone with a pseudo-karstic morphology, the intermediary unit is more silty-sandstone than the last but less than the unit from below. To establish a conceptual model of the groundwater flows of the Bonifacio aquifer, a hydrochemical (major ions, δ18O, δ2H, 3H) and hydrodynamic investigation was carried out on 12 wells, 1 spring and 1 river since May 2011. Vertical recharge is dominant in the centre of the aquifer where unsaturated zone is thicker, while on the aquifer boundaries with the granitic area, lateral flow was significant. Environmental tracers approach had clearly showed the important role of the boundaries conditions for the groundwater flow behavior of the aquifer of Bonifacio and the necessity of an investigation larger than the aquifer itself due to its limited spatial extension.

  10. Comprehensive Analysis of Mouse Bitter Taste Receptors Reveals Different Molecular Receptive Ranges for Orthologous Receptors in Mice and Humans.

    PubMed

    Lossow, Kristina; Hübner, Sandra; Roudnitzky, Natacha; Slack, Jay P; Pollastro, Federica; Behrens, Maik; Meyerhof, Wolfgang

    2016-07-15

    One key to animal survival is the detection and avoidance of potentially harmful compounds by their bitter taste. Variable numbers of taste 2 receptor genes expressed in the gustatory end organs enable bony vertebrates (Euteleostomi) to recognize numerous bitter chemicals. It is believed that the receptive ranges of bitter taste receptor repertoires match the profiles of bitter chemicals that the species encounter in their diets. Human and mouse genomes contain pairs of orthologous bitter receptor genes that have been conserved throughout evolution. Moreover, expansions in both lineages generated species-specific sets of bitter taste receptor genes. It is assumed that the orthologous bitter taste receptor genes mediate the recognition of bitter toxins relevant for both species, whereas the lineage-specific receptors enable the detection of substances differently encountered by mice and humans. By challenging 34 mouse bitter taste receptors with 128 prototypical bitter substances in a heterologous expression system, we identified cognate compounds for 21 receptors, 19 of which were previously orphan receptors. We have demonstrated that mouse taste 2 receptors, like their human counterparts, vary greatly in their breadth of tuning, ranging from very broadly to extremely narrowly tuned receptors. However, when compared with humans, mice possess fewer broadly tuned receptors and an elevated number of narrowly tuned receptors, supporting the idea that a large receptor repertoire is the basis for the evolution of specialized receptors. Moreover, we have demonstrated that sequence-orthologous bitter taste receptors have distinct agonist profiles. Species-specific gene expansions have enabled further diversification of bitter substance recognition spectra.

  11. Comprehensive Analysis of Mouse Bitter Taste Receptors Reveals Different Molecular Receptive Ranges for Orthologous Receptors in Mice and Humans.

    PubMed

    Lossow, Kristina; Hübner, Sandra; Roudnitzky, Natacha; Slack, Jay P; Pollastro, Federica; Behrens, Maik; Meyerhof, Wolfgang

    2016-07-15

    One key to animal survival is the detection and avoidance of potentially harmful compounds by their bitter taste. Variable numbers of taste 2 receptor genes expressed in the gustatory end organs enable bony vertebrates (Euteleostomi) to recognize numerous bitter chemicals. It is believed that the receptive ranges of bitter taste receptor repertoires match the profiles of bitter chemicals that the species encounter in their diets. Human and mouse genomes contain pairs of orthologous bitter receptor genes that have been conserved throughout evolution. Moreover, expansions in both lineages generated species-specific sets of bitter taste receptor genes. It is assumed that the orthologous bitter taste receptor genes mediate the recognition of bitter toxins relevant for both species, whereas the lineage-specific receptors enable the detection of substances differently encountered by mice and humans. By challenging 34 mouse bitter taste receptors with 128 prototypical bitter substances in a heterologous expression system, we identified cognate compounds for 21 receptors, 19 of which were previously orphan receptors. We have demonstrated that mouse taste 2 receptors, like their human counterparts, vary greatly in their breadth of tuning, ranging from very broadly to extremely narrowly tuned receptors. However, when compared with humans, mice possess fewer broadly tuned receptors and an elevated number of narrowly tuned receptors, supporting the idea that a large receptor repertoire is the basis for the evolution of specialized receptors. Moreover, we have demonstrated that sequence-orthologous bitter taste receptors have distinct agonist profiles. Species-specific gene expansions have enabled further diversification of bitter substance recognition spectra. PMID:27226572

  12. Why do we like sweet taste: A bitter tale?

    PubMed

    Beauchamp, Gary K

    2016-10-01

    Sweet is widely considered to be one of a small number of basic or primary taste qualities. Liking for sweet tasting substances is innate, although postnatal experiences can shape responses. The power of sweet taste to induce consumption and to motivate behavior is profound, suggesting the importance of this sense for many species. Most investigators presume that the ability to identify sweet molecules through the sense of taste evolved to allow organisms to detect sources of readily available glucose from plants. Perhaps the best evidence supporting this presumption are recent discoveries in comparative biology demonstrating that species in the order Carnivora that do not consume plants also do not perceive sweet taste due to the pseudogenization of a component of the primary sweet taste receptor. However, arguing against this idea is the observation that the sweetness of a plant, or the amount of easily metabolizable sugars contained in the plant, provides little quantitative indication of the plant's energy or broadly conceived food value. Here it is suggested that the perceptual ratio of sweet taste to bitter taste (a signal for toxicity) may be a better gauge of a plant's broadly conceived food value than sweetness alone and that it is this ratio that helps guide selection or rejection of a potential plant food. PMID:27174610

  13. Enzymatic hydrolysis of defatted mackerel protein with low bitter taste

    NASA Astrophysics Data System (ADS)

    Hou, Hu; Li, Bafang; Zhao, Xue

    2011-03-01

    Ultrasound-assisted solvent extraction was confirmed as a novel, effective method for separating lipid from mackerel protein, resulting in a degreasing rate (DR) of 95% and a nitrogen recovery (NR) of 88.6%. To obtain protein hydrolysates with high nitrogen recovery and low bitter taste, enzymatic hydrolysis was performed using eight commercially available proteases. It turned out that the optimum enzyme was the `Mixed enzymes for animal proteolysis'. An enzyme dosage of 4%, a temperature of 50°, and a hydrolysis time of 300 min were found to be the optimum conditions to obtain high NR (84.28%) and degree of hydrolysis (DH, 16.18%) by orthogonal experiments. Glutamic acid was the most abundant amino acid of MDP (defatted mackerel protein) and MDPH (defatted mackerel protein hydrolysates). Compared with the FAO/WHO reference protein, the essential amino acid chemical scores (CS) were greater than 1.0 (1.0-1.7) in MDPH, which is reflective of high nutritional value. This, coupled with the light color and slight fishy odor, indicates that MDPH would potentially have a wide range of applications such as nutritional additives, functional ingredients, and so on.

  14. Sources of nitrate contamination and age of water in large karstic springs of Florida

    USGS Publications Warehouse

    Katz, B.G.

    2004-01-01

    In response to concerns about the steady increase in nitrate concentrations over the past several decades in many of Florida's first magnitude spring waters (discharge ???2.8 m3/s), multiple isotopic and other chemical tracers were analyzed in water samples from 12 large springs to assess sources and timescales of nitrate contamination. Nitrate-N concentrations in spring waters ranged from 0.50 to 4.2 mg/L, and ??15N values of nitrate in spring waters ranged from 2.6 to 7.9 per mil. Most ??15N values were below 6 per mil indicating that inorganic fertilizers were the dominant source of nitrogen in these waters. Apparent ages of groundwater discharging from springs ranged from 5 to about 35 years, based on multi-tracer analyses (CFC-12, CFC-113, SF6, 3H/3He) and a piston flow assumption; however, apparent tracer ages generally were not concordant. The most reliable spring-water ages appear to be based on tritium and 3He data, because concentrations of CFCs and SF6 in several spring waters were much higher than would be expected from equilibration with modern atmospheric concentrations. Data for all tracers were most consistent with output curves for exponential and binary mixing models that represent mixtures of water in the Upper Floridan aquifer recharged since the early 1960s. Given that groundwater transit times are on the order of decades and are related to the prolonged input of nitrogen from multiple sources to the aquifer, nitrate could persist in groundwater that flows toward springs for several decades due to slow transport of solutes through the aquifer matrix.

  15. Sensomics analysis of key bitter compounds in the hard resin of hops (Humulus lupulus L.) and their contribution to the bitter profile of Pilsner-type beer.

    PubMed

    Dresel, Michael; Dunkel, Andreas; Hofmann, Thomas

    2015-04-01

    Recent brewing trials indicated the occurrence of valuable bitter compounds in the hard resin fraction of hop. Aiming at the discovery of these compounds, hop's ε-resin was separated by means of a sensory guided fractionation approach and the key taste molecules were identified by means of UV/vis, LC-TOF-MS, and 1D/2D-NMR studies as well as synthetic experiments. Besides a series of literature known xanthohumol derivatives, multifidol glucosides, flavon-3-on glycosides, and p-coumaric acid esters, a total of 11 bitter tastants are reported for the first time, namely, 1",2"-dihydroxanthohumol F, 4'-hydroxytunicatachalcone, isoxantholupon, 1-methoxy-4-prenylphloroglucinol, dihydrocyclohumulohydrochinone, xanthohumols M, N, and P, and isoxanthohumols M, N, and P, respectively. Human sensory analysis revealed low bitter recognition threshold concentrations ranging from 5 (co-multifidol glucopyranoside) to 198 μmol/L (trans-p-coumaric acid ethyl ester) depending on their chemical structure. For the first time, LC-MS/MS quantitation of these taste compounds in Pilsner-type beer, followed by taste re-engineering experiments, revealed the additive contribution of iso-α-acids and the identified hard resin components to be truly necessary and sufficient for constructing the authentic bitter percept of beer. Finally, brewing trails using the ε-resin as the only hop source impressively demonstrated the possibility to produce beverages strongly enriched with prenylated hop flavonoids.

  16. Sensomics analysis of key bitter compounds in the hard resin of hops (Humulus lupulus L.) and their contribution to the bitter profile of Pilsner-type beer.

    PubMed

    Dresel, Michael; Dunkel, Andreas; Hofmann, Thomas

    2015-04-01

    Recent brewing trials indicated the occurrence of valuable bitter compounds in the hard resin fraction of hop. Aiming at the discovery of these compounds, hop's ε-resin was separated by means of a sensory guided fractionation approach and the key taste molecules were identified by means of UV/vis, LC-TOF-MS, and 1D/2D-NMR studies as well as synthetic experiments. Besides a series of literature known xanthohumol derivatives, multifidol glucosides, flavon-3-on glycosides, and p-coumaric acid esters, a total of 11 bitter tastants are reported for the first time, namely, 1",2"-dihydroxanthohumol F, 4'-hydroxytunicatachalcone, isoxantholupon, 1-methoxy-4-prenylphloroglucinol, dihydrocyclohumulohydrochinone, xanthohumols M, N, and P, and isoxanthohumols M, N, and P, respectively. Human sensory analysis revealed low bitter recognition threshold concentrations ranging from 5 (co-multifidol glucopyranoside) to 198 μmol/L (trans-p-coumaric acid ethyl ester) depending on their chemical structure. For the first time, LC-MS/MS quantitation of these taste compounds in Pilsner-type beer, followed by taste re-engineering experiments, revealed the additive contribution of iso-α-acids and the identified hard resin components to be truly necessary and sufficient for constructing the authentic bitter percept of beer. Finally, brewing trails using the ε-resin as the only hop source impressively demonstrated the possibility to produce beverages strongly enriched with prenylated hop flavonoids. PMID:25793563

  17. Flow-system analysis of the Madison and Minnelusa aquifers in the Rapid City area, South Dakota--conceptual model

    USGS Publications Warehouse

    Long, Andrew J.; Putnam, Larry D.

    2002-01-01

    The conceptual model of the Madison and Minnelusa aquifers in the Rapid City area synthesizes the physical geography, hydraulic properties, and ground-water flow components of these important aquifers. The Madison hydrogeologic unit includes the karstic Madison aquifer, which is defined as the upper, more permeable 100 to 200 ft of the Madison Limestone, and the Madison confining unit, which consists of the lower, less permeable part of the Madison Limestone and the Englewood Formation. Overlying the Madison hydrogeologic unit is the Minnelusa hydrogeologic unit, which includes the Minnelusa aquifer in the upper, more permeable 200 to 300 ft and the Minnelusa confining unit in the lower, less permeable part. The Madison and Minnelusa hydrogeologic units outcrop in the study area on the eastern flank of the Black Hills where recharge occurs from streamflow losses and areal recharge. The conceptual model describes streamflow recharge, areal recharge, ground-water flow, storage in aquifers and confining units, unsaturated areas, leakage between aquifers, discharge from artesian springs, and regional outflow. Effective transmissivities estimated for the Madison aquifer range from 500 to 20,000 ft2/d and for the Minnelusa aquifer from 500 to 10,000 ft2/d. Localized anisotropic transmissivity in the Madison aquifer has tensor ratios as high as 45:1. Vertical hydraulic conductivities for the Minnelusa confining unit determined from aquifer tests range from 1.3x10-3 to 3.0x10-1 ft/d. The confined storage coefficient of the Madison and Minnelusa hydrogeologic units was estimated as 3x10-4 ft/d. Specific yield was estimated as 0.09 for the Madison and Minnelusa aquifers and 0.03 for the Madison and Minnelusa confining units. Potentiometric surfaces for the Madison and Minnelusa aquifers have a general easterly gradient of about 70 ft/mi with local variations. Temporal change in hydraulic head in the Madison and Minnelusa aquifers ranged from about 5 to 95 ft in water years

  18. Characterization of a soluble phosphatidic acid phosphatase in bitter melon (Momordica charantia).

    PubMed

    Cao, Heping; Sethumadhavan, Kandan; Grimm, Casey C; Ullah, Abul H J

    2014-01-01

    Momordica charantia is often called bitter melon, bitter gourd or bitter squash because its fruit has a bitter taste. The fruit has been widely used as vegetable and herbal medicine. Alpha-eleostearic acid is the major fatty acid in the seeds, but little is known about its biosynthesis. As an initial step towards understanding the biochemical mechanism of fatty acid accumulation in bitter melon seeds, this study focused on a soluble phosphatidic acid phosphatase (PAP, 3-sn-phosphatidate phosphohydrolase, EC 3.1.3.4) that hydrolyzes the phosphomonoester bond in phosphatidate yielding diacylglycerol and P(i). PAPs are typically categorized into two subfamilies: Mg(2+)-dependent soluble PAP and Mg(2+)-independent membrane-associated PAP. We report here the partial purification and characterization of an Mg(2+)-independent PAP activity from developing cotyledons of bitter melon. PAP protein was partially purified by successive centrifugation and UNOsphere Q and S columns from the soluble extract. PAP activity was optimized at pH 6.5 and 53-60 °C and unaffected by up to 0.3 mM MgCl2. The K(m) and Vmax values for dioleoyl-phosphatidic acid were 595.4 µM and 104.9 ηkat/mg of protein, respectively. PAP activity was inhibited by NaF, Na(3)VO(4), Triton X-100, FeSO4 and CuSO4, but stimulated by MnSO4, ZnSO4 and Co(NO3)2. In-gel activity assay and mass spectrometry showed that PAP activity was copurified with a number of other proteins. This study suggests that PAP protein is probably associated with other proteins in bitter melon seeds and that a new class of PAP exists as a soluble and Mg(2+)-independent enzyme in plants. PMID:25203006

  19. Quantitation and bitter taste contribution of saponins in fresh and cooked white asparagus (Asparagus officinalis L.).

    PubMed

    Dawid, Corinna; Hofmann, Thomas

    2014-02-15

    A sensitive HPLC-MS/MS method was developed enabling the simultaneous quantification of bitter-tasting mono- and bidesmosidic saponins in fresh and processed asparagus (Asparagus officinalis L.). Based on quantitative data and bitter taste recognition thresholds, dose-over-threshold factors were determined for the first time to determine the bitter impact of the individual saponins. Although 3-O-[α-L-rhamnopyranosyl-(1→2)-α-L-rhamnopyranosyl-(1 → 4)-β-D-glucopyranosyl]-(25R/S)-spirost-5-ene-3β-ol was found based on dose-over-threshold factors to be the predominant bitter saponin in raw asparagus spears, 3-O-[α-L-rhamnopyranosyl-(1 → 2)-{α-L-rhamnopyranosyl-(1 → 4)}-β-D-glucopyranosyl]-26-O-[β-D-glucopyranosyl]-(25R)-22-hydroxyfurost-5-ene-3β,26-diol, 3-O-[α-L-rhamnopyranosyl-(1 → 2)-{α-L-rhamnopyranosyl-(1 → 4)}-β-D-glucopyranosyl]-26-O-[β-D-glucopyranosyl]-(25S)-22-hydroxyfurost-5-ene-3β,26-diol, and (25R)- and (25S)-furost-5-en-3β,22,26-triol-3-O-[α-L-rhamnopyranosyl-(1 → 4)-β-D-glucopyranoside]-26-O-β-D-glucopyranoside were found as key bitter contributors after cooking. Interestingly, the monodesmosidic saponins 5a/b were demonstrated for the first time to be the major contributor to the bitter taste of fresh asparagus spears, while the bidesmosides 1a/b and 2a/b may be considered the primary determinants for the bitter taste of cooked asparagus.

  20. Quantitation and bitter taste contribution of saponins in fresh and cooked white asparagus (Asparagus officinalis L.).

    PubMed

    Dawid, Corinna; Hofmann, Thomas

    2014-02-15

    A sensitive HPLC-MS/MS method was developed enabling the simultaneous quantification of bitter-tasting mono- and bidesmosidic saponins in fresh and processed asparagus (Asparagus officinalis L.). Based on quantitative data and bitter taste recognition thresholds, dose-over-threshold factors were determined for the first time to determine the bitter impact of the individual saponins. Although 3-O-[α-L-rhamnopyranosyl-(1→2)-α-L-rhamnopyranosyl-(1 → 4)-β-D-glucopyranosyl]-(25R/S)-spirost-5-ene-3β-ol was found based on dose-over-threshold factors to be the predominant bitter saponin in raw asparagus spears, 3-O-[α-L-rhamnopyranosyl-(1 → 2)-{α-L-rhamnopyranosyl-(1 → 4)}-β-D-glucopyranosyl]-26-O-[β-D-glucopyranosyl]-(25R)-22-hydroxyfurost-5-ene-3β,26-diol, 3-O-[α-L-rhamnopyranosyl-(1 → 2)-{α-L-rhamnopyranosyl-(1 → 4)}-β-D-glucopyranosyl]-26-O-[β-D-glucopyranosyl]-(25S)-22-hydroxyfurost-5-ene-3β,26-diol, and (25R)- and (25S)-furost-5-en-3β,22,26-triol-3-O-[α-L-rhamnopyranosyl-(1 → 4)-β-D-glucopyranoside]-26-O-β-D-glucopyranoside were found as key bitter contributors after cooking. Interestingly, the monodesmosidic saponins 5a/b were demonstrated for the first time to be the major contributor to the bitter taste of fresh asparagus spears, while the bidesmosides 1a/b and 2a/b may be considered the primary determinants for the bitter taste of cooked asparagus. PMID:24128498

  1. Assessment of nitrate-N contamination in the Chunnakam aquifer system, Jaffna Peninsula, Sri Lanka.

    PubMed

    Vithanage, Meththika; Mikunthan, Thushyanthi; Pathmarajah, Selverajah; Arasalingam, Sutharsiny; Manthrithilake, Herath

    2014-01-01

    Jaffna peninsula in Sri Lanka is an area of intensive agriculture using extensive organic and inorganic nitrogenous compounds and hence, this study was focused on assessing vulnerability of karstic aquifer system with specific focus on nitrate contamination, and compare loads of nitrate from agriculture. The total number of the wells sampled in the Chunnakam aquifer is 44. The coverage of wells with measurements of nitrate and nitrite concentrations in the database covering the study period from Januray, 2011 to August, 2011. The intrinsic vulnerability of the area is estimated by the DRASTIC model and the modified DRASTIC method was used to determine the nitrate-specific vulnerability of the aquifers. Average concentrations of nitrate-N and nitrite-N during the study period were 4.869 and 0.014 mg/L respectively. The average number of wells exceeding permissible level of NO3-N is approximately 6-12, which means that about 14-28% out of the 44 wells. Modified DRASTIC (DI) index value computed as explained above increased from DI = 177 to a range of 182 to 197. In spite of the increase, the Modified DI values show that the aquifer vulnerability specific to nitrate contamination remains in "high" category. Although nitrogen loading at the domestic sources and irrigation is of the same order of magnitude, the loading from fertilizer input is much larger which is about 15 times higher. This finding suggests that the fertilizer input in agricultural areas constitute a significant contribution to the nitrogen content in the groundwater and soils in agricultural areas of Jaffna.

  2. Quantification of phosphorus transport from a karstic agricultural watershed to emerging spring water.

    PubMed

    Mellander, Per-Erik; Jordan, Philip; Melland, Alice R; Murphy, Paul N C; Wall, David P; Mechan, Sarah; Meehan, Robert; Kelly, Coran; Shine, Oliver; Shortle, Ger

    2013-06-18

    The degree to which waters in a given watershed will be affected by nutrient export can be defined as that watershed's nutrient vulnerability. This study applied concepts of specific phosphorus (P) vulnerability to develop intrinsic groundwater vulnerability risk assessments in a 32 km(2) karst watershed (spring zone of contribution) in a relatively intensive agricultural landscape. To explain why emergent spring water was below an ecological impairment threshold, concepts of P attenuation potential were investigated along the nutrient transfer continuum based on soil P buffering, depth to bedrock, and retention within the aquifer. Surface karst features, such as enclosed depressions, were reclassified based on P attenuation potential in soil at the base. New techniques of high temporal resolution monitoring of P loads in the emergent spring made it possible to estimate P transfer pathways and retention within the aquifer and indicated small-medium fissure flows to be the dominant pathway, delivering 52-90% of P loads during storm events. Annual total P delivery to the main emerging spring was 92.7 and 138.4 kg total P (and 52.4 and 91.3 kg as total reactive P) for two monitored years, respectively. A revised groundwater vulnerability assessment was used to produce a specific P vulnerability map that used the soil and hydrogeological P buffering potential of the watershed as key assumptions in moderating P export to the emergent spring. Using this map and soil P data, the definition of critical source areas in karst landscapes was demonstrated. PMID:23672730

  3. Perchlorate in the San Antonio Segment of the Edwards Aquifer, Texas

    NASA Astrophysics Data System (ADS)

    Fahlquist, L.; Rajagapolan, S.; Jackson, W. A.

    2007-12-01

    Perchlorate has been detected in drinking-water supplies and can have adverse health effects on humans by disrupting thyroid function. Perchlorate and other constituents were analyzed from ground-water samples that were collected in 2004-06 from 99 wells completed in the San Antonio segment of the Edwards aquifer as part of the U.S. Geological Survey National Water-Quality Assessment Program. The fractured karstic carbonate Edwards aquifer, declared a sole-source aquifer by the U.S. Environmental Protection Agency, supplies nearly one-half million acre-feet per year for drinking water and other uses. Wells were located in a variety of land-use settings that included rangeland, agriculture, and urban; well types included domestic, public, and observation. Perchlorate was detected in 98 percent of the samples, and concentrations ranged from less than 0.05 to 3 micrograms per liter (μg/L). Five samples contained concentrations greater than 1 μg/L and were from wells in the urban northern San Antonio area. The results from three samples that contained perchlorate at concentrations greater than 2 μg/L are anomalous. Chloride concentration ranged from 5.6 to 69 milligrams per liter, typical for freshwater in the Edwards aquifer. No significant (r2 greater than 0.7) correlations were observed when perchlorate concentrations were correlated with depth to water, total depth of well, or concentrations of bicarbonate, nitrate, phosphate, sulfate, bromide, chloride, fluoride, calcium, magnesium, potassium, sodium, strontium, and dissolved solids. Tritium concentrations ranged from 1.2 to 2.9 tritium units in 31 of the 99 samples and indicate at least some fraction of modern water (post-atmospheric nuclear tests). No correlation between apparent tritium age and perchlorate concentration was observed, a possible indication that anthropogenic influences are not affecting observed perchlorate concentrations. The molar ratio of chloride to perchlorate ranged from 17,000 to 320

  4. Modeling coastal aquifers in a Mediterranean area: the example of Taranto gulf (southern Italy)

    NASA Astrophysics Data System (ADS)

    De Filippis, Giovanna; Giudici, Mauro; Negri, Sergio; Margiotta, Stefano; Cattaneo, Laura; Vassena, Chiara

    2015-04-01

    Water resources stored in coastal aquifers are of strategic relevance for several regions throughout the world and in particular in the Mediterranean basin. They are extremely important in areas characterized by heavy urbanization, active industrial or touristic systems, where the need for fresh water is very acute and, sometimes, they are the only water resources available. This in turn can lead to the phenomenon of seawater intrusion because of aquifer overexploitation to satisfy the demand of an increasing population in coastal plains. Furthermore, karstic aquifers are well known for their specific vulnerability to natural and human-induced contamination, due to their particular characteristics such as thin soils, point recharge in dolines and swallow holes and increased hydraulic conductivity. Within this framework, the Taranto gulf is an example of paramount importance. In fact the presence of a wide industrial area close to the city of Taranto and the numerous maritime and military activities in the harbor area favored the increase of population density in the XX century. Moreover, they constitute factors of great concern for the protection of groundwater quality and quantity, in particular for the presence of the highly-vulnerable basins of Mar Piccolo and Mar Grande. In this area, groundwater resources are stored in a karst multilayered aquifer, which is very complex from the hydrostratigraphic point of view. Furthermore, the presence of highly water-demanding activities makes the seawater intrusion phenomenon very serious, especially along the coastline. In order to characterize the groundwater dynamic in the study area, we discuss the hydraulic relationships between the different hydrostratigraphic units and between the sea and the aquifer system by developing a numerical groundwater model to test and refine the preliminary conceptual model and estimate the most uncertain hydraulic parameters. To achieve these objectives, we used different data-sets to

  5. Hydrologic response in karstic-ridge wetlands to rainfall and evapotranspiration, central Florida, 2001-2003

    USGS Publications Warehouse

    Knowles, Leel; Phelps, G.G.; Kinnaman, Sandra L.; German, Edward R.

    2005-01-01

    Two internally drained karstic wetlands in central Florida-Boggy Marsh at the Hilochee Wildlife Management Area and a large unnamed wetland at the Lyonia Preserve-were studied during 2001-03 to gain a better understanding of the net-recharge function that these wetlands provide, the significance of exchanges with ground water with regard to wetland water budgets, and the variability in wetland hydrologic response to a range of climate conditions. These natural, relatively remote and unaltered wetlands were selected to provide a baseline of natural wetland hydrologic variability to which anthropogenic influences on wetland hydrology could be compared. Large departures from normal rainfall during the study were fortuitous, and allowed monitoring of hydrologic processes over a wide range of climate conditions. Wetland responses varied greatly as a result of climate conditions that ranged from moderate drought to extremely moist. Anthropogenic activities influenced water levels at both study sites; however, because these activities were brief relative to the duration of the study, sufficient data were collected during unimpacted periods to allow for the following conclusions to be made. Water budgets developed for Boggy Marsh and the Lyonia large wetland showed strong similarity between the flux terms of rainfall, evaporation, net change in storage, and the net ground-water exchange residual. Runoff was assumed to be negligible. Of the total annual flux at Boggy Marsh, rainfall accounted for 45 percent; evaporation accounted for 25 percent; net change in storage accounted for 25 percent; and the net residual accounted for 5 percent. At the Lyonia large wetland, rainfall accounted for 44 percent; evaporation accounted for 29 percent; net change in storage accounted for 21 percent; and the net residual accounted for 6 percent of the total annual flux. Wetland storage and ground-water exchange were important when compared to the total water budget at both wetlands. Even

  6. Dissolved Carbon Flux and Mass Balance From a Wetland-Dominated Karstic Headwater Catchment

    NASA Astrophysics Data System (ADS)

    Duval, T. P.; Waddington, J. M.; Branfireun, B. A.

    2009-05-01

    between the wetland types. Significant stream recharge back into the dolomite occurred through the calcareous fen, resulting in the peatland acting as a net 'sink' of DOC and DIC, which was stronger in the drier summer than the wetter autumn. The stream became unconfined through the cedar swamp, with appreciable depression storage that resulted in the wetland becoming a greater net sink of DOC and DIC in the autumn when increased stream discharge into the swamp resulted in greater depression storage. The marsh received significant groundwater inputs from the karstic dolomite, diluting the stream of DOC, but increasing the flux of DIC, resulting in the wetland acting as a sink of DOC but a source of DIC. These data demonstrate that the presence of calcareous bedrock overwhelms the influence of wetland sediments on the dynamics of terrestrial-stream linkages to carbon transport, and that groundwater systems and wetland type can significantly affect the stream-borne flux of carbon from watersheds.

  7. AMS radiocarbon dating of pollen concentrates in a karstic lake system

    NASA Astrophysics Data System (ADS)

    Fletcher, William; Zielhofer, Christoph; Mischke, Steffen; Campbell, Jennifer; Bryant, Charlotte; Fink, David; Xu, Xiaomei

    2016-04-01

    In lake sediments where terrestrial macrofossils are rare or absent, AMS radiocarbon dating of pollen concentrates represents an important alternative solution for developing a robust and high resolution chronology suitable for Bayesian modelling of age-depth relationships. Here we report an application of the dense media separation approach (Vandergoes and Prior, Radiocarbon 45:479-492, 2003) to Holocene lake sediments from karstic Lake Sidi Ali, Morocco (33° 03'N, 05° 00'W; 2,080 m a.s.l.). Paired dates on terrestrial (macrofossil) and aquatic (ostracod) samples, and dating of bulk sediment surface material at the site indicate varying reservoir effects of up to 900 yr and highlight the need to date terrestrial carbon sources. Dating of pollen concentrates is a viable approach at Lake Sidi Ali, as pollen concentrations are high (~200,000 grains/cc), and pollen assemblages typically contain only minor percentages (<1%) of aquatic pollen. Following laboratory trials, 23 pollen concentrates alongside laboratory standards (anthracite, IAEA C5 wood) were prepared and dated following the heavy liquid (sodium polytungstate, SPT) density separation protocol. A series of SPT solutions of progressively decreasing density (1.9-1.15 s.g.) were used to divide the samples into several fractions. The pollen purity of these fractions was evaluated by microscopic analysis of smear slides, and the richest fraction(s) were selected for dating. Sieving at 10 μm and at 50/125 μm (depending on the size of predominant pollen grains) was used to further concentrate the pollen grains, and the samples were freeze dried to determine the dry weight of material. The results show that the highest purity of pollen is sample dependent and may typically be achieved in the fractions precipitating at 1.4-1.2 s.g. With sieving, terrestrial pollen purity of ~50-80% can be achieved, offering a considerable improvement in terms of terrestrial carbon content over bulk sediment. These values reflect

  8. Microbial community diversity associated with moonmilk deposits in a karstic cave system in Ireland

    NASA Astrophysics Data System (ADS)

    Rooney, D.; Hutchens, E.; Clipson, Nick; McDermott, Frank

    2009-04-01

    has been unaltered by human disturbance or practices. The aim of this study was to examine microbial community diversity associated with moonmilk deposits at Ballynamintra Cave, Ireland using automated ribosomal intergenic spacer analysis (ARISA). The results revealed considerable bacterial and fungal diversity associated with moonmilk in a karstic cave system, suggesting that the microbial community implicated in moonmilk formation may be more diverse than previously thought. These results suggest that microbes may have important functional roles in subterranean environments. Although the moonmilk in this study was largely comprised of calcite, microbial involvement in calcite precipitation could result in the bioavailability of a range of organic compounds for subsequent microbial metabolism. References: Baskar, S., Baskar, R., Mauclaire, L., and McKenzie, J.A. 2006. Microbially induced calcite precipitation in culture experiments: Possible origin for stalactites in Sahastradhara caves, Dehradun, India. Current Science 90: 58-64. Burford, E.P., Fomina, M., Gadd, G. 2003. Fungal involvement in bioweathering and biotrasformations of rocks and minerals. Min Mag 67(6):1172-1155. Engel, A.S., Stern, L.A., Bennett, P.C. 2004. Microbial contributions to cave formation: new insights into sulfuric acid speleogenesis. Geology 32(5): 369-372. Gadd, G.M. (2004). Mycotransformation of organic and inorganic substrates. Mycologist 18: 60-70. Northup, D., Barns, S.M., Yu, Laura, E., Spilde, M.N., Schelble, R.T., Dano, K.E., Crossey, L.J., Connolly, C.A., Boston, P.J., and Dahm, C.N. 2003. Diverse microbial communities inhabiting ferromanganese deposits in Lechuguilla and Spider Caves. Environmental Microbiology 5(11): 1071-1086.

  9. Effect of drying methods on total antioxidant capacity of bitter gourd (momordica charantia) fruit

    NASA Astrophysics Data System (ADS)

    Tan, Ee Shian; Abdullah, Aminah; Maskat, Mohammad Yusof

    2013-11-01

    The effect of thermal and non-thermal drying methods on hydrophilic and lipophilic antioxidant capacities of bitter gourd fruit was investigated in this study. The bitter gourd fruits were dried by following methods: (i) oven drying 40°C, (ii) oven drying 50°C, (iii) oven drying 60°C, (iv) microwave drying (medium low power), (v) microwave drying (medium power) and (vi) freeze drying. Pure acetone and hexane were used to extract the hydrophilic and lipophilic antioxidant compounds from dried bitter gourd fruits. Freeze dried extracts reported to have highest values in DPPH scavenging activity (hydrophilic and lipophilic fractions), FRAP (lipophilic fraction) and TPC (hydrophilic and lipophilic fraction). Thermal drying slightly increased the values of DPPH scavenging activity, FRAP and TPC assays for hydrophilic extracts. Results concluded bitter gourd fruit is a good source of natural antioxidants and its total antioxidant quality was most preserved by freeze drying. Additionally, the higher value reported in DPPH scavenging activity, FRAP and TPC assays for lipophilic extracts than the hydrophilic extracts suggested that the lipophilic antioxidant compounds of bitter gourd fruit might possess stronger antioxidant power than its counterpart.

  10. Antioxidant and antimicrobial activities of bitter and sweet apricot (Prunus armeniaca L.) kernels.

    PubMed

    Yiğit, D; Yiğit, N; Mavi, A

    2009-04-01

    The present study describes the in vitro antimicrobial and antioxidant activity of methanol and water extracts of sweet and bitter apricot (Prunus armeniaca L.) kernels. The antioxidant properties of apricot kernels were evaluated by determining radical scavenging power, lipid peroxidation inhibition activity and total phenol content measured with a DPPH test, the thiocyanate method and the Folin method, respectively. In contrast to extracts of the bitter kernels, both the water and methanol extracts of sweet kernels have antioxidant potential. The highest percent inhibition of lipid peroxidation (69%) and total phenolic content (7.9 +/- 0.2 microg/mL) were detected in the methanol extract of sweet kernels (Hasanbey) and in the water extract of the same cultivar, respectively. The antimicrobial activities of the above extracts were also tested against human pathogenic microorganisms using a disc-diffusion method, and the minimal inhibitory concentration (MIC) values of each active extract were determined. The most effective antibacterial activity was observed in the methanol and water extracts of bitter kernels and in the methanol extract of sweet kernels against the Gram-positive bacteria Staphylococcus aureus. Additionally, the methanol extracts of the bitter kernels were very potent against the Gram-negative bacteria Escherichia coli (0.312 mg/mL MIC value). Significant anti-candida activity was also observed with the methanol extract of bitter apricot kernels against Candida albicans, consisting of a 14 mm in diameter of inhibition zone and a 0.625 mg/mL MIC value.

  11. A bitter sweet asynchrony. The relation between eating attitudes, dietary restraint on smell and taste function.

    PubMed

    Stafford, Lorenzo D; Tucker, Megan; Gerstner, Nora

    2013-11-01

    Research has demonstrated that individuals with eating disorders have an impaired sense of smell and taste, though the influence of eating attitudes, dietary restraint and gender in a non-clinical sample is unknown. In two studies (study 1: 32 females, 28 males; study 2: 29 females) participants completed questionnaires relating to Eating Attitudes (EAT) and dietary restraint (DEBQ) followed by an odour (study 1: isoamyl acetate, study 2: chocolate) threshold and taste test. In study 2 we also measured the number of fungiform papillae taste buds. Study one revealed that increases in pathological eating attitudes predicted poorer olfactory sensitivity (males/females) and lower bitterness ratings for the bitter tastant (females only), suggestive of poorer taste acuity. In study two we found that both eating attitudes and restraint predicted poorer sensitivity to an odour associated to a forbidden food (chocolate) and that increasing eating attitudes predicted higher sweetness ratings for the bitter tastant. Interestingly increases in restraint were associated with an increased number of fungiform papillae which was not related to bitter or sweet intensity. These findings demonstrate that in a young healthy sample that subtle differences in eating pathology and dietary restraint predict impaired olfactory function to food related odours. Further that perception of bitter tastants is poorer with changes in eating pathology but not dietary restraint. PMID:23811349

  12. Comprehensive sensomics analysis of hop-derived bitter compounds during storage of beer.

    PubMed

    Intelmann, Daniel; Haseleu, Gesa; Dunkel, Andreas; Lagemann, Annika; Stephan, Andreas; Hofmann, Thomas

    2011-03-01

    For the first time, quantitative LC-MS/MS profiling of 56 hop-derived sensometabolites contributing to the bitter taste of beer revealed a comprehensive insight into the transformation of individual bitter compounds during storage of beer. The proton-catalyzed cyclization of trans-iso-α-acids was identified to be the quantitatively predominant reaction leading to lingering, harsh bitter tasting tri- and tetracyclic compounds such as, e.g. the cocongeners tricyclocohumol, tricyclocohumene, isotricyclocohumene, tetracyclocohumol, and epitetracyclocohumol, accumulating in beer during storage with increasing time and temperature. The key role of these transformation products in storage-induced trans-iso-α-acid degradation was verified for the first time by multivariate statistics and hierarchical cluster analysis of the sensomics data obtained for a series of commercial beer samples stored under controlled conditions. The present study offers the scientific basis for a knowledge-based extension of the shelf life of the desirable beer's bitter taste and the delay of the onset of the less preferred harsh bitter aftertaste by controlling the initial pH value of the beer and by keeping the temperature as low as possible during storage of the final beverage.

  13. Absence of furanocoumarins in Advantra Z® (Citrus aurantium, bitter orange) extracts.

    PubMed

    Stohs, Sidney J; Miller, Howard; Romano, Felice

    2014-09-01

    Grapefruit (Citrus paradisi) juice is known for its ability to alter drug metabolism through inhibition of the cytochrome P450-3A4 (CYP3A4) system, and result in drug-food interactions that may be life threatening. The primary active ingredients in grapefruit responsible for these effects are the furanocoumarins bergapten, bergamottin, and 6',7'-dihydroxybergamottin (DHB). Bergamottin and DHB appear to be the most important in terms of adverse drug interactions. Furanocoumarins are present in the juices and fruits of other Citrus species including C. aurantium (bitter oranges). Bergapten is the predominant furanocoumarin in bitter orange. Bitter orange extracts are widely used in products associated with weight loss, sports performance, and energy production. Questions have been raised about the potential of bitter orange extracts to cause drug interactions. This study examined the furanocoumarin content of four standardized bitter orange extracts (Advantra Z®) by liquid chromatography-mass spectroscopy. The results indicated that the total furanocoumarin content of each of the four extracts was less than 20 μg/g, amounts insufficient to exert significant effects on the metabolism of susceptible drugs in human subjects at the doses commonly used for these extracts.

  14. Bitter and sweet taste receptors in the respiratory epithelium in health and disease

    PubMed Central

    Lee, Robert J.; Cohen, Noam A.

    2016-01-01

    Taste receptors on the tongue communicate information to the brain about the nutrient content or potential toxicity of ingested foods. However, recent research has now shown that taste receptors are also expressed far beyond the tongue, from the airway and gastrointestinal epithelia to the pancreas and brain. The functions of many of these so-called extraoral taste receptors remain unknown, but emerging basic science and clinical evidence suggests that bitter and sweet taste receptors in the airway are important in sensing bacteria and regulating innate immunity. This review focuses on the role of bitter and sweet taste receptors in human airway innate immunity and the potential clinical relevance to airway infections. The T2R38 bitter taste receptor in sinonasal cilia detects bitter bacterial quorum-sensing molecules and activates nitric oxide-dependent innate immune responses. Polymorphisms that underlie T2R38 functionality also appear to be involved in susceptibility to upper respiratory infection and chronic rhinosinusitis (CRS). Bitter and sweet receptors in specialized sinonasal solitary chemosensory cells control antimicrobial peptide secretion, which may have important implications for airway infections in CRS patients as well as patients with diabetes mellitus. Future research on taste receptors in the airway has tremendous potential to identify immune mechanisms involved in host-pathogen interactions and thus reveal novel therapeutic targets. PMID:25391251

  15. Mass spectrometric determination of the predominant adrenergic protoalkaloids in bitter orange (Citrus aurantium).

    PubMed

    Nelson, Bryant C; Putzbach, Karsten; Sharpless, Katherine E; Sander, Lane C

    2007-11-28

    The predominant adrenergic protoalkaloid found in the peel and fruit of bitter orange, Citrus aurantium, is synephrine. Synephrine is reputed to have thermogenic properties and is used as a dietary supplement to enhance energy and promote weight loss. However, there exists some concern that the consumption of dietary supplements containing synephrine or similar protoalkaloids may contribute to adverse cardiovascular events. This study developed and validated a positive-ion mode liquid chromatography/tandem mass spectrometry (LC/MS/MS) method for the quantitative determination of the major (synephrine) and minor (tyramine, N-methyltyramine, octopamine, and hordenine) adrenergic protoalkaloids in a suite of National Institute of Standards and Technology (NIST) bitter orange Standard Reference Materials (SRMs): SRM 3258 Bitter Orange Fruit, SRM 3259 Bitter Orange Extract, and SRM 3260 Bitter Orange Solid Oral Dosage Form. The limit of quantitation (LOQ) for all protoalkaloids is approximately 1 pg on-column, except for octopamine (20 pg on-column). Additionally, the method has a linear dynamic range of > or =3 orders of magnitude for all of the protoalkaloids. Individual, as well as "total", protoalkaloid levels (milligrams per kilogram) in the NIST SRMs were determined and compared to the levels measured by an independent liquid chromatography/fluorescence detection (LC/FD) method. Satisfactory concordance between the LC/MS/MS and LC/FD protoalkaloid measurements was demonstrated. LC/MS/MS analysis of the protoalkaloids in the SRMs resulted in mean measurement imprecision levels of < or =10% coefficient of variation (% CV). PMID:17966980

  16. A bitter sweet asynchrony. The relation between eating attitudes, dietary restraint on smell and taste function.

    PubMed

    Stafford, Lorenzo D; Tucker, Megan; Gerstner, Nora

    2013-11-01

    Research has demonstrated that individuals with eating disorders have an impaired sense of smell and taste, though the influence of eating attitudes, dietary restraint and gender in a non-clinical sample is unknown. In two studies (study 1: 32 females, 28 males; study 2: 29 females) participants completed questionnaires relating to Eating Attitudes (EAT) and dietary restraint (DEBQ) followed by an odour (study 1: isoamyl acetate, study 2: chocolate) threshold and taste test. In study 2 we also measured the number of fungiform papillae taste buds. Study one revealed that increases in pathological eating attitudes predicted poorer olfactory sensitivity (males/females) and lower bitterness ratings for the bitter tastant (females only), suggestive of poorer taste acuity. In study two we found that both eating attitudes and restraint predicted poorer sensitivity to an odour associated to a forbidden food (chocolate) and that increasing eating attitudes predicted higher sweetness ratings for the bitter tastant. Interestingly increases in restraint were associated with an increased number of fungiform papillae which was not related to bitter or sweet intensity. These findings demonstrate that in a young healthy sample that subtle differences in eating pathology and dietary restraint predict impaired olfactory function to food related odours. Further that perception of bitter tastants is poorer with changes in eating pathology but not dietary restraint.

  17. Famotidine orally disintegrating tablets: bitterness comparison of original and generic products.

    PubMed

    Tokuyama, Emi; Matsunaga, Chiharu; Yoshida, Koichi; Mifsud, Jean-Christophe; Irie, Tetsumi; Yoshida, Miyako; Uchida, Takahiro

    2009-04-01

    The purpose of the present study was to compare the palatability of the original and eight generic versions of famotidine orally disintegrating tablets by means of human gustatory sensation tests, a comparison of the release profiles, and using an automated taste sensor, the alpha-Astree Electronic Tongue. In the gustatory sensation test, the original product (Gaster D, 10 mg) showed the lowest bitterness intensity. Among the eight generic products tested, the variance in the sweetness intensity was not great, but there were large variances in the intensity of bitterness, some of the generic products being significantly more bitter than that of the original product. On the other hand, some generic products show similar bitterness level as the original product. In a study of release profiles, the original product had the lowest release rates of both famotidine and aspartame; in comparison, some of the generic products had high release rates of famotidine and aspartame, even in the initial stages. Whereas some generic products had low release rates of famotidine and aspartame. Finally, sample solutions were analysed using the taste sensor. There was a good correlation between the taste predicted by principal component analysis and the Euclidean distance obtained by the taste sensor, and bitterness intensities obtained in the human gustatory tests.

  18. Superimposed Pristine Limestone Aquifers with Marked Hydrochemical Differences Exhibit Distinct Fungal Communities

    PubMed Central

    Nawaz, Ali; Purahong, Witoon; Lehmann, Robert; Herrmann, Martina; Küsel, Kirsten; Totsche, Kai U.; Buscot, François; Wubet, Tesfaye

    2016-01-01

    Fungi are one important group of eukaryotic microorganisms in a diverse range of ecosystems, but their diversity in groundwater ecosystems is largely unknown. We used DNA-based pyro-tag sequencing of the fungal internal transcribed spacer (ITS) rDNA gene to investigate the presence and community structure of fungi at different sampling sites of two superimposed limestone aquifers ranging from 8.5 to 84 m depth in the newly established Hainich Critical Zone Exploratory (Hainich CZE). We detected a diversity of fungal OTUs in groundwater samples of all sampling sites. The relative percentage abundance of Basidiomycota was higher in the upper aquifer assemblage, whilst Ascomycota dominated the lower one. In parallel to differences in the hydrochemistry we found distinct fungal communities at all sampling sites. Classification into functional groups revealed an overwhelming majority of saprotrophs. Finding taxa common to all analyzed groundwater sites, point to a groundwater specific fungal microbiome. The presence of different functional groups and, in particular plant and cattle pathogens that are not typical of subsurface habitats, suggests links between the surface and subsurface biogeosphere due to rapid transportation across the fracture networks typical of karstic regions during recharge episodes. However, further studies including sampling series extended in both time and space are necessary to confirm this hypothesis. PMID:27242696

  19. Hydrological role of karst in the Chalk aquifer of Upper Normandy, France

    NASA Astrophysics Data System (ADS)

    El Janyani, Sanae; Dupont, Jean-Paul; Massei, Nicolas; Slimani, Smail; Dörfliger, Nathalie

    2014-05-01

    The role of karst on large-scale groundwater flow is defined for the Chalk aquifer of Upper Normandy (western Paris Basin), France. In the regional context, chalk plateaus occupy the greater part of watersheds and are the main sites of groundwater recharge. Previous studies focused on karstic output systems in the valleys and less on water-level variations in the recharge zones upstream. This study assesses the relevant hydrogeological processes using time-series data (boreholes and springs) recorded along a down-gradient hydrologeological cross-section in two selected watersheds. These hydrological data are interpreted in the framework of previous descriptions of the morphological organization of the study area's karst network. The results highlight the hydrological role of (1) the input karst (vertical conduits) which drains recharging water, (2) the output karst (sub-horizontal conduits widely developed in the vicinity of valleys in the surface watersheds) which drains the output flows, and (3) the connections between these two (input and output) networks, which control the upstream water levels and allow quick transfer to springs, particularly after strong rainfall events. A conceptual model of the hydrological functioning of this covered karst aquifer is established, which should serve for the structuring and parameterization of a numerical model.

  20. Superimposed Pristine Limestone Aquifers with Marked Hydrochemical Differences Exhibit Distinct Fungal Communities.

    PubMed

    Nawaz, Ali; Purahong, Witoon; Lehmann, Robert; Herrmann, Martina; Küsel, Kirsten; Totsche, Kai U; Buscot, François; Wubet, Tesfaye

    2016-01-01

    Fungi are one important group of eukaryotic microorganisms in a diverse range of ecosystems, but their diversity in groundwater ecosystems is largely unknown. We used DNA-based pyro-tag sequencing of the fungal internal transcribed spacer (ITS) rDNA gene to investigate the presence and community structure of fungi at different sampling sites of two superimposed limestone aquifers ranging from 8.5 to 84 m depth in the newly established Hainich Critical Zone Exploratory (Hainich CZE). We detected a diversity of fungal OTUs in groundwater samples of all sampling sites. The relative percentage abundance of Basidiomycota was higher in the upper aquifer assemblage, whilst Ascomycota dominated the lower one. In parallel to differences in the hydrochemistry we found distinct fungal communities at all sampling sites. Classification into functional groups revealed an overwhelming majority of saprotrophs. Finding taxa common to all analyzed groundwater sites, point to a groundwater specific fungal microbiome. The presence of different functional groups and, in particular plant and cattle pathogens that are not typical of subsurface habitats, suggests links between the surface and subsurface biogeosphere due to rapid transportation across the fracture networks typical of karstic regions during recharge episodes. However, further studies including sampling series extended in both time and space are necessary to confirm this hypothesis. PMID:27242696

  1. Glycerol metabolism and bitterness producing lactic acid bacteria in cidermaking.

    PubMed

    Garai-Ibabe, G; Ibarburu, I; Berregi, I; Claisse, O; Lonvaud-Funel, A; Irastorza, A; Dueñas, M T

    2008-02-10

    Several lactic acid bacteria were isolated from bitter tasting ciders in which glycerol was partially removed. The degradation of glycerol via glycerol dehydratase pathway was found in 22 out of 67 isolates. The confirmation of glycerol degradation by this pathway was twofold: showing their glycerol dehydratase activity and detecting the presence of the corresponding gene by a PCR method. 1,3-propanediol (1,3-PDL) and 3-hydroxypropionic acid (3-HP) were the metabolic end-products of glycerol utilization, and the accumulation of the acrolein precursor 3-hydroxypropionaldehyde (3-HPA) was also detected in most of them. The strain identification by PCR-DGGE rpoB showed that Lactobacillus collinoides was the predominant species and only 2 belonged to Lactobacillus diolivorans. Environmental conditions conducting to 3-HPA accumulation in cidermaking were studied by varying the fructose concentration, pH and incubation temperature in L. collinoides 17. This strain failed to grow with glycerol as sole carbon source and the addition of fructose enhanced both growth and glycerol degradation. Regarding end-products of glycerol metabolism, 1,3-PDL was always the main end-product in all environmental conditions assayed, the only exception being the culture with 5.55 mM fructose, where equimolar amounts of 1,3-PDL and 3-HP were found. The 3-HPA was transitorily accumulated in the culture medium under almost all culture conditions, the degradation rate being notably slower at 15 degrees C. However, no disappearance of 3-HPA was found at pH 3.6, a usual value in cider making. After sugar exhaustion, L. collinoides 17 oxidated lactic acid and/or mannitol to obtain energy and these oxidations were accompanied by the removal of the toxic 3-HPA increasing the 1,3-PDL, 3-HP and acetic acid contents. PMID:18180066

  2. Intensive exploitation of a karst aquifer leads to Cryptosporidium water supply contamination.

    PubMed

    Khaldi, S; Ratajczak, M; Gargala, G; Fournier, M; Berthe, T; Favennec, L; Dupont, J P

    2011-04-01

    Groundwater from karst aquifers is an important source of drinking water worldwide. Outbreaks of cryptosporidiosis linked to surface water and treated public water are regularly reported. Cryptosporidium oocysts are resistant to conventional drinking water disinfectants and are a major concern for the water industry. Here, we examined conditions associated with oocyst transport along a karstic hydrosystem, and the impact of intensive exploitation on Cryptosporidium oocyst contamination of the water supply. We studied a well-characterized karstic hydrosystem composed of a sinkhole, a spring and a wellbore. Thirty-six surface water and groundwater samples were analyzed for suspended particulate matter, turbidity, electrical conductivity, and Cryptosporidium and Giardia (oo)cyst concentrations. (Oo)cysts were identified and counted by means of solid-phase cytometry (ChemScan RDI(®)), a highly sensitive method. Cryptosporidium oocysts were detected in 78% of both surface water and groundwater samples, while Giardia cysts were found in respectively 22% and 8% of surface water and groundwater samples. Mean Cryptosporidium oocyst concentrations were 29, 13 and 4/100 L at the sinkhole, spring and wellbore, respectively. Cryptosporidium oocysts were transported from the sinkhole to the spring and the wellbore, with respective release rates of 45% and 14%, suggesting that oocysts are subject to storage and remobilization in karst conduits. Principal components analysis showed that Cryptosporidium oocyst concentrations depended on variations in hydrological forcing factors. All water samples collected during intensive exploitation contained oocysts. Control of Cryptosporidium oocyst contamination during intensive exploitation is therefore necessary to ensure drinking water quality.

  3. Assessing the precision of the iGrav superconducting gravimeter for hydrological models and karstic hydrological process identification

    NASA Astrophysics Data System (ADS)

    Fores, B.; Champollion, C.; Moigne, N. Le; Bayer, R.; Chéry, J.

    2016-10-01

    In this paper we present the potential of a new compact superconducting gravimeter (GWR iGrav) designed for groundwater monitoring. At first, three years of continuous gravity data are evaluated and the performance of the instrument is investigated. With repeated absolute gravity measurements using a Micro-g Lacoste FG5, the calibration factor (-894.8 nm.s-2.V-1) and the long term drift of this instrument (45 nm.s-2 per year) are estimated for the first time with a high precision and found to be respectively constant and linear for this particular iGrav. The low noise level performance is found similar to those of previous superconducting gravimeters and leads to gravity residuals coherent with local hydrology. The iGrav is located in a fully instrumented hydro-geophysical observatory on the Durzon karstic basin (Larzac plateau, south of France). Rain gauges and a flux tower (evapo-transpiration measurements) are used to evaluate the groundwater mass balance at the local scale. Water mass balance demonstrates that the karst is only capacitive: all the rainwater is temporarily stored in the matrix and fast transfers to the spring through fractures are insignificant in this area. Moreover, the upper part of the karst around the observatory appears to be representative of slow transfer of the whole catchment. Indeed, slow transfer estimated on the site fully supports the low-flow discharge at the only spring which represents all groundwater outflows from the catchment. In the last part of the paper, reservoir models are used to characterize the water transfer and storage processes. Particular highlights are done on the advantages of continuous gravity data (compared to repeated campaigns) and on the importance of local accurate meteorological data to limit misinterpretation of the gravity observations. The results are complementary with previous studies at the basin scale and show a clear potential for continuous gravity time series assimilation in hydrological

  4. Hydro-geophysical observations integration in numerical model: case study in Mediterranean karstic unsaturated zone (Larzac, france)

    NASA Astrophysics Data System (ADS)

    Champollion, Cédric; Fores, Benjamin; Le Moigne, Nicolas; Chéry, Jean

    2016-04-01

    Karstic hydro-systems are highly non-linear and heterogeneous but one of the main water resource in the Mediterranean area. Neither local measurements in boreholes or analysis at the spring can take into account the variability of the water storage. Since a few years, ground-based geophysical measurements (such as gravity, electrical resistivity or seismological data) allows following water storage in heterogeneous hydrosystems at an intermediate scale between boreholes and basin. Behind classical rigorous monitoring, the integration of geophysical data in hydrological numerical models in needed for both processes interpretation and quantification. Since a few years, a karstic geophysical observatory (GEK: Géodésie de l'Environnement Karstique, OSU OREME, SNO H+) has been setup in the Mediterranean area in the south of France. The observatory is surrounding more than 250m karstified dolomite, with an unsaturated zone of ~150m thickness. At the observatory water level in boreholes, evapotranspiration and rainfall are classical hydro-meteorological observations completed by continuous gravity, resistivity and seismological measurements. The main objective of the study is the modelling of the whole observation dataset by explicit unsaturated numerical model in one dimension. Hydrus software is used for the explicit modelling of the water storage and transfer and links the different observations (geophysics, water level, evapotranspiration) with the water saturation. Unknown hydrological parameters (permeability, porosity) are retrieved from stochastic inversions. The scale of investigation of the different observations are discussed thank to the modelling results. A sensibility study of the measurements against the model is done and key hydro-geological processes of the site are presented.

  5. Integrating borehole logs and aquifer tests in aquifer characterization

    USGS Publications Warehouse

    Paillet, Frederick L.; Reese, R.S.

    2000-01-01

    Integration of lithologic logs, geophysical logs, and hydraulic tests is critical in characterizing heterogeneous aquifers. Typically only a limited number of aquifer tests can be performed, and these need to be designed to provide hydraulic properties for the principle aquifers in the system. This study describes the integration of logs and aquifer tests in the development of a hydrostratigraphic model for the surficial aquifer system in and around Big Cypress National Preserve in eastern Collier County, Florida. Borehole flowmeter tests provide qualitative permeability profiles in most of 26 boreholes drilled in the Study area. Flow logs indicate the depth of transmissive units, which are correlated across the study area. Comparison to published studies in adjacent areas indicates that the main limestone aquifer of the 000000Tamiami Formation in the study area corresponds with the gray limestone aquifer in western Dade County and the water table and lower Tamiami Aquifer in western Collier County. Four strategically located, multiwell aquifer tests are used to quantify the qualitative permeability profiles provided by the flowmeter log analysis. The hydrostratigraphic model based on these results defines the main aquifer in the central part of the study area as unconfined to semiconfined with a transmissivity as high as 30,000 m2/day. The aquifer decreases in transmissivity to less than 10,000 m2/day in some parts of western Collier County, and becomes confined to the east and northeast of the study area, where transmissivity decreases to below 5000 m2/day.Integration of lithologic logs, geophysical logs, and hydraulic tests is critical in characterizing heterogeneous aquifers. Typically only a limited number of aquifer tests can be performed, and these need to be designed to provide hydraulic properties for the principle aquifers in the system. This study describes the integration of logs and aquifer tests in the development of a hydrostratigraphic model for the

  6. Application of Herbal Medicines with Bitter Flavor and Cold Property on Treating Diabetes Mellitus.

    PubMed

    Chen, Hongdong; Guo, Jing; Pang, Bing; Zhao, Linhua; Tong, Xiaolin

    2015-01-01

    Diabetes mellitus has been a global pandemic. Traditional Chinese Medicine has been used on diabetes mellitus for thousands of years and the modern Chinese medicine studies have found a curative effect of herbal medicine with bitter flavor and cold property on diabetes. This review will introduce the theory summary of flavor and property in TCM, argument basis, the evidences from clinical trails and animal experiments, the possible antidiabetic mechanisms, and advantages on lowering glucose of herbal medicines with bitter flavor and cold property and take rhizome, Chinese rhubarb, and Momordica charantia, the three herbal medicines with bitter flavor and cold property, as examples to illustrate the exact antidiabetic effect. It is hoped that this review can provide some ideas and inspiration for the treatment of diabetes with herbal medicine.

  7. Determination of metrafenone in bitter gourd and soil by GC with ECD.

    PubMed

    Wang, Siwei; Liu, Yanping; Sun, Haibin

    2016-04-01

    A method for determination of metrafenone residues in bitter gourd and soil was developed. All samples were extracted with ethyl acetate, purified with the glass column of florisil and NH2-SPE column, analyzed by gas chromatography with electronic capture detector (GC-ECD). The results showed that it had good linearity in the range of 0.01-2 mg/L and the correlation coefficient (r) was 0.9999. The average recoveries of metrafenone in bitter gourd and soil were 83.51-91.75% and 84.76-91.72% with the relative standard deviation of 3.48-9.18% and 4.23-7.25%, respectively. The limit of detection was estimated to be 0.005 mg/kg, the minimum concentration of detection in bitter gourd and soil was 1 × 10(-2) mg/kg. PMID:26593479

  8. Application of Herbal Medicines with Bitter Flavor and Cold Property on Treating Diabetes Mellitus

    PubMed Central

    Chen, Hongdong; Guo, Jing; Pang, Bing; Zhao, Linhua; Tong, Xiaolin

    2015-01-01

    Diabetes mellitus has been a global pandemic. Traditional Chinese Medicine has been used on diabetes mellitus for thousands of years and the modern Chinese medicine studies have found a curative effect of herbal medicine with bitter flavor and cold property on diabetes. This review will introduce the theory summary of flavor and property in TCM, argument basis, the evidences from clinical trails and animal experiments, the possible antidiabetic mechanisms, and advantages on lowering glucose of herbal medicines with bitter flavor and cold property and take rhizome, Chinese rhubarb, and Momordica charantia, the three herbal medicines with bitter flavor and cold property, as examples to illustrate the exact antidiabetic effect. It is hoped that this review can provide some ideas and inspiration for the treatment of diabetes with herbal medicine. PMID:26557150

  9. Localization of phosphatidylinositol signaling components in rat taste cells: Role in bitter taste transduction

    SciTech Connect

    Hwang, P.M.; Verma, A.; Bredt, D.S.; Snyder, S.H. )

    1990-10-01

    To assess the role of phosphatidylinositol turnover in taste transduction we have visualized, in rat tongue, ATP-dependent endoplasmic reticular accumulation of {sup 45}Ca{sup 2+}, inositol 1,4,5-trisphosphate receptor binding sites, and phosphatidylinositol turnover monitored by autoradiography of ({sup 3}H)cytidine diphosphate diacylglycerol formed from ({sup 3}H)cytidine. Accumulated {sup 45}Ca{sup 2+}, inositol 1,4,5-trisphosphate receptors, and phosphatidylinositol turnover are selectively localized to apical areas of the taste buds of circumvallate papillae, which are associated with bitter taste. Further evidence for a role of phosphatidylinositol turnover in bitter taste is our observation of a rapid, selective increase in mass levels of inositol 1,4,5-trisphosphate elicited by low concentrations of denatonium, a potently bitter tastant.

  10. First report of phytophthora fruit rot on bitter gourd (Mormodica charantia) and sponge gourd (Luffa cylindrica) caused by phytophthora capsici

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Luffa sponge (smooth gourd) and bitter gourds (bitter melon) are specialty cucurbit vegetables cultivated in the United States (US) on a small scale for select markets. Luffa gourds are also grown for the sponge obtained from dried fruit for personal hygiene and skin care. These two cucurbits prod...

  11. Does mere exposure mediate sensitivity to bitter taste on consumer liking and acceptability of whole grain foods?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Health benefits of whole grains (WG) are well known, yet consumption by Americans falls far short of recommended amounts. Roughly 75% of Americans are sensitive to bitter taste, and WG are known to contain bitter tasting phenolic compounds. It has been reported that individuals with the highest se...

  12. A comparative analysis of genetic diversity in bitter gourd (Momordica charantia L.) genotypes using RAPD and ISSR markers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bitter gourd (Momordica charantia L.) or bitter melon is a cucurbit of major economic importance where it is widely cultivated (India, China, Africa, and South America). The morphology (i.e., growth habit, maturity, and fruit shape, size, colour and surface texture) of Indian M. charantia germplasm...

  13. Preliminary evaluation of resistance to powdery mildew (Podosphaera xanthii) in AVRDC collections of bitter gourd (Momordica charantia L.)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bitter gourd (Momordica charantia L.) is an important market vegetable in Asia, where it is also used in folk medicine to manage type 2 diabetes. Powdery mildew caused by Podosphaera xanthii is a serious fungal disease of bitter gourd and yield losses of up to 50% have been reported. After observi...

  14. Prunasin Hydrolases during Fruit Development in Sweet and Bitter Almonds1[C][W][OA

    PubMed Central

    Sánchez-Pérez, Raquel; Belmonte, Fara Sáez; Borch, Jonas; Dicenta, Federico; Møller, Birger Lindberg; Jørgensen, Kirsten

    2012-01-01

    Amygdalin is a cyanogenic diglucoside and constitutes the bitter component in bitter almond (Prunus dulcis). Amygdalin concentration increases in the course of fruit formation. The monoglucoside prunasin is the precursor of amygdalin. Prunasin may be degraded to hydrogen cyanide, glucose, and benzaldehyde by the action of the β-glucosidase prunasin hydrolase (PH) and mandelonitirile lyase or be glucosylated to form amygdalin. The tissue and cellular localization of PHs was determined during fruit development in two sweet and two bitter almond cultivars using a specific antibody toward PHs. Confocal studies on sections of tegument, nucellus, endosperm, and embryo showed that the localization of the PH proteins is dependent on the stage of fruit development, shifting between apoplast and symplast in opposite patterns in sweet and bitter cultivars. Two different PH genes, Ph691 and Ph692, have been identified in a sweet and a bitter almond cultivar. Both cDNAs are 86% identical on the nucleotide level, and their encoded proteins are 79% identical to each other. In addition, Ph691 and Ph692 display 92% and 86% nucleotide identity to Ph1 from black cherry (Prunus serotina). Both proteins were predicted to contain an amino-terminal signal peptide, with the size of 26 amino acid residues for PH691 and 22 residues for PH692. The PH activity and the localization of the respective proteins in vivo differ between cultivars. This implies that there might be different concentrations of prunasin available in the seed for amygdalin synthesis and that these differences may determine whether the mature almond develops into bitter or sweet. PMID:22353576

  15. Berberine induces GLP-1 secretion through activation of bitter taste receptor pathways.

    PubMed

    Yu, Yunli; Hao, Gang; Zhang, Quanying; Hua, Wenyan; Wang, Meng; Zhou, Wenjia; Zong, Shunlin; Huang, Ming; Wen, Xiaozhou

    2015-09-15

    Our previous studies revealed that berberine-mediated GLP-1 secretion was a possible mechanism for berberine exerting good effects on hyperglycemia. This study was designed to ascertain whether berberine-induced secretion of GLP-1 was related with activation of bitter taste receptors expressed in gastrointestinal tract. Western blotting results showed that TAS2R38, a subtype of bitter taste receptor, was expressed on human enteroendocrine NCI-H716 cells. GLP-1 secretion induced by berberine from NCI-H716 cells was inhibited by incubation with anti-TAS2R38 antibody. We further performed gene silencing using siRNA to knockdown TAS2R38 from NCI-H716 cells, which showed that siRNA knockdown of the TAS2R38 reduced berberine-mediated GLP-1 secretion. We adopted inhibitors of PLC and TRPM5 known to be involved in bitter taste transduction to investigate the underlying pathways mediated in berberine-induced GLP-1 secretion. It was found that PLC inhibitor U73122 inhibited berberine-induced GLP-1 release in NCI-H716 cells, while TRPM5 blocker quinine failed to attenuate berberine-induced secretion of GLP-1. The present results demonstrated that berberine stimulated GLP-1 secretion via activation of gut-expressed bitter taste receptors in a PLC-dependent manner. Because berberine was found to be a ligand of bitter taste receptor, the results of present study may provide an explanation for some bitter taste substance obtain hypoglycemic effect.

  16. Pungent and bitter, cytotoxic and antiviral terpenoids from some bryophytes and inedible fungi.

    PubMed

    Asakawa, Yoshinori; Nagashima, Fumihiro; Hashimoto, Toshihiro; Toyota, Masao; Ludwiczuk, Agnieszka; Komala, Ismiarni; Ito, Takuya; Yagi, Yasuyuki

    2014-03-01

    Most liverworts elaborate characteristic odiferous, pungent and bitter tasting compounds many of which show antimicrobial, antifungal, antiviral, allergenic contact dermatitis, cytotoxic, insecticidal, anti-HIV, superoxide anion radical release, plant growth regulatory, neurotrophic, NO production inhibitory, muscle relaxant, antiobesity, piscicidal and nematocidal activities. Several inedible mushrooms produce female spider pheromones, strong antioxidant, and cytotoxic compounds. The present paper is concerned with the extraction and isolation of terpenoids from some bryophytes and inedible fungi and their pungent and bitter taste, and cytotoxic and antiviral activity.

  17. Rainfall-recharge relationships within a karstic terrain in the Eastern Mediterranean semi-arid region, Israel: δ 18O and δD characteristics

    NASA Astrophysics Data System (ADS)

    Ayalon, Avner; Bar-Matthews, Miryam; Sass, Eytan

    1998-06-01

    Annual rainfall variations and processes in the upper vadose zone exert a profound influence on the chemical and isotopic compositions of waters of carbonate aquifers in semi-arid climatic zones. In order to define these processes we have studied the surface temperatures during rainfall events, the isotopic composition of rain, infiltrating and groundwaters. This study was carried out within a karstic terrain (Soreq Cave), Israel, located in Cenomanian dolomitic rocks, approximately 40 km inland of the Mediterranean Sea, and 400 m above sea level. The climate is typical of the Eastern Mediterranean semi-arid conditions, with a rainy winter and dry summer and the average annual rainfall in the area is ˜500 mm. Close monitoring indicates that the δD and δ 18O values of individual rainstorm events decrease with increasing rainfall. Annual average isotopic values of years with rainfall of 500-600 mm do not vary systematically. Years with extreme rainfall values define a negative covariation between the δ 18O and rainfall. The δD-δ 18O relationship of all rain events of more than 20 mm fall on the Mediterranean Meteoric Water Line (MMWL) with a slope of ˜8 and d-excesses of 20-30%. These rain events occur when mid-winter surface temperatures are 5 to 10°C. Rainfall events of less than 20 mm, mainly occurring at above 10°C, have slopes of less than 8 and smaller d-excess as a consequence of evaporation processes beneath the clouds. Two main water-types infiltrating into the cave are recognized: slow- and fast-drip. Slow-drip occurs from the tips of stalactites and takes place throughout the year; these waters represent seepage water that remains in the upper vadose zone for up to several decades. Fast-drip emanates from fissures in the cave roof during the winter seasons; these waters represent vadose flow with a short residence time of less than 1 year. The infiltration of the fast-drip water into the cave depends on the fracture system of the rock cover and on

  18. High Temperature Aquifer Storage

    NASA Astrophysics Data System (ADS)

    Ueckert, Martina; Niessner, Reinhard; Baumann, Thomas

    2016-04-01

    Combined heat and power generation (CHP) is highly efficient because excess heat is used for heating and/or process energy. However, the demand of heat energy varies considerably throughout the year while the demand for electrical energy is rather constant. It seems economically and ecologically highly beneficial for municipalities and large power consumers such as manufacturing plants to store excess heat in groundwater aquifers and to recuperate this energy at times of higher demand. Within the project High Temperature Aquifer Storage, scientists investigate storage and recuperation of excess heat energy into the bavarian Malm aquifer. Apart from high transmissivity and favorable pressure gradients, the hydrochemical conditions are crucial for long-term operation. An enormous technical challenge is the disruption of the carbonate equilibrium - modeling results indicated a carbonate precipitation of 10 - 50 kg/d in the heat exchangers. The test included five injection pulses of hot water (60 °C up to 110 °C) and four tracer pulses, each consisting of a reactive and a conservative fluorescent dye, into a depth of about 300 m b.s.l. resp. 470 m b.s.l. Injection and production rates were 15 L/s. To achieve the desired water temperatures, about 4 TJ of heat energy were necessary. Electrical conductivity, pH and temperature were recorded at a bypass where also samples were taken. A laboratory container at the drilling site was equipped for analysing the concentration of the dyes and the major cations at sampling intervals of down to 15 minutes. Additional water samples were taken and analysed in the laboratory. The disassembled heat exchanger prooved that precipitation was successfully prevented by adding CO2 to the water before heating. Nevertheless, hydrochemical data proved both, dissolution and precipitation processes in the aquifer. This was also suggested by the hydrochemical modelling with PhreeqC and is traced back to mixture dissolution and changing

  19. Strategies to improve palatability and increase consumption intentions for Momordica charantia (bitter melon): A vegetable commonly used for diabetes management

    PubMed Central

    2011-01-01

    Background Although beneficial to health, dietary phytonutrients are bitter, acid and/or astringent in taste and therefore reduce consumer choice and acceptance during food selection. Momordica charantia, commonly known as bitter melon has been traditionally used in Ayurvedic and Chinese medicine to treat diabetes and its complications. The aim of this study was to develop bitter melon-containing recipes and test their palatability and acceptability in healthy individuals for future clinical studies. Methods A cross-sectional sensory evaluation of bitter melon-containing ethnic recipes was conducted among 50 healthy individuals. The primary endpoints assessed in this analysis were current consumption information and future intentions to consume bitter melon, before and after provision of attribute- and health-specific information. A convenience sample of 50, self-reported non-diabetic adults were recruited from the University of Hawaii. Sensory evaluations were compared using two-way ANOVA, while differences in stage of change (SOC) before and after receiving health information were analyzed by Chi-square (χ2) analyses. Results Our studies indicate that tomato-based recipes were acceptable to most of the participants and readily acceptable, as compared with recipes containing spices such as curry powder. Health information did not have a significant effect on willingness to consume bitter melon, but positively affected the classification of SOC. Conclusions This study suggests that incorporating bitter foods in commonly consumed food dishes can mask bitter taste of bitter melon. Furthermore, providing positive health information can elicit a change in the intent to consume bitter melon-containing dishes despite mixed palatability results. PMID:21794176

  20. Characteristics of subtropic karstic Dinaride Lake in its unstable geothectonic regime

    NASA Astrophysics Data System (ADS)

    Krstic, N.

    2009-04-01

    Geotectonic evolution of Dinarides started in Mid-Cretaceous, when this part of African Plate approached Stable Europe. Geodynamic style is as follow: "subduction-termination / colision (Paleocene / Eocene), collision (Eocene), postcollision / colapse (Oligocene / early Miocene)" (Cvetković et al., 2004). Longlasting melting of lower crust (ibid: fig. 11). "The gravity colapse of the Dinaride orogen is inferred from the faulth pattern and shape" as mirrored in sedimetary record of lacustrine basin (ibid). So, at the turn from Paleogene to Neogene on Dinarides was formed large subtropical karstic system of lakes. Another part of Africa is the Adriatic Plate mowing northwards under the Alps (Schmid et al., 2006: fig. 1 and there in). Two coal seams (brown coal and lignite), formed during colateral catastrofic earthquakes, indicate two main phases of tectonic push of Adriatic plate. Evolution of Dinaric Lake(s) from shallow freshwater aquatorium toward deep saline lake was influenced by northward movements of Adriatic Plate and the response of Pannonian Mass. The sediment column of Dinaride Neogene was devided into tree parts (Milojević, 1963). They lay, in places, above reddish (continental) Oligocene sediments with Helix (Čičić & Milojević, 1977), but mostly in the Sava trough (Ugljevik, Banovići). Otherwise above Mesozoic and Paleozoic rocks. First part: basal zone above lie several brown coal seams indicating that the Adriatic Plate push was divided into phases. Catastrophic earthquake pull down the forest together with its large dwellers (Chalicotherium grande, an of Ungulata with claws) and sorted tree trunks at southern side of the lake Plevlja (Krstić et al., 1994). In this period freshwater ostracodes, and numerous characean gyrogonites, among them a genus similar to the Oligocene Harissichara, fill up some of beds. None of Congeria pelecipods are present. Charophyta algae making yellowish-brown limestone in Middle Bosnian depression lie just bellow

  1. High Temperature Aquifer Storage

    NASA Astrophysics Data System (ADS)

    Ueckert, Martina; Niessner, Reinhard; Baumann, Thomas

    2015-04-01

    Combined heat and power generation (CHP) is highly efficient because excess heat is used for heating and/or process energy. However, the demand of heat energy varies considerably throughout the year while the demand for electrical energy is rather constant. It seems economically and ecologically highly beneficial for municipalities and large power consumers such as manufacturing plants to store excess heat in groundwater aquifers and to recuperate this energy at times of higher demand. Apart from the hydrogeological conditions, high transmissivity and favorable pressure gradients, the hydrochemical conditions are crucial for long-term operation. Within the project High Temperature Aquifer Storage, scientists investigate storage and recuperation of excess heat energy into the bavarian Malm aquifer. After one year of planning, construction, and the successful drilling of a research well to 495 m b.s.l. the first large scale heat storage test in the Malm aquifer was finished just before Christmas 2014. An enormous technical challenge was the disruption of the carbonate equilibrium - modeling results indicated a carbonate precipitation of 10-50 kg/d in the heat exchangers. The test included five injection pulses of hot water (60 °C up to 110 °C) and four tracer pulses, each consisting of a reactive and a conservative fluorescent dye. Injection and production rates were 15 L/s. About 4 TJ of heat energy were necessary to achieve the desired water temperatures. Electrical conductivity, pH and temperature were recorded at a bypass where also samples were taken. A laboratory container at the drilling site was equipped for the analysis of the concentration of the tracers and the cation concentrations at sampling intervals of down to 15 minutes. Additional water samples were taken and analyzed for major ions and trace elements in the laboratory. The disassembled heat exchanger proved that precipitation was successfully prevented by adding CO2 to the water before heating

  2. Interaction of a fresh water lake and a karstic spring via a syncline fold.

    PubMed

    Rezaei, Abolfazl; Zare, Mohammad; Raeisi, Ezzatollah; Ghanbari, Reza Namdar

    2013-03-01

    Kaftar Lake is a high-altitude fresh water lake located in High Zagros, south of Iran. Despite the high annual evaporation to precipitation ratio in the area, lake water electrical conductivity is usually lower than 1000 µS/cm, this may be due to high seepage from the floor of the lake. Therefore, the hypothesis of possible underground connections between Namdan Basin, where the lake is located, and the surrounding basins with lower elevation (Aspas and Dehbid Basins) was investigated. Hydrogeology, hydrochemistry, and stable isotopes data of the lake and surrounding basins along with the lake water balance study were applied to test the hypothesis. Results indicate that Kaftar Lake has no connection with Aspas Basin in south, but it is hydraulically connected to Dehbid Basin. In Dehbid Basin, "Ghasr_e_Yaghoob spring" (average discharge ≅1200 L/s) emerges from a small outcrop (about 0.8 km(2) ) of Daryan limestone Formation, where this outcrop is much smaller than the required recharge area for such average discharge rate. The study shows that this spring is recharged by Kaftar Lake and Namdan Basin aquifer, through Daryan Formation of Gandboee Syncline located to the northern part of the lake.

  3. Estimation of hydraulic conductivity of a coastal aquifer using satellite imagery

    NASA Astrophysics Data System (ADS)

    Rebolledo-Vieyra, M.; Iglesias-Prieto, R.; Marino-Tapia, I.

    2012-12-01

    The northern Yucatan Peninsula is characterized by a young and dynamic karstic system that yields very high secondary porosity and permeability. However, we have little, if none, knowledge about the hydraulic conductivity and the amount of groundwater being discharged in to ocean. Here we present and estimation of the hydraulic conductivity and quantity of groundwater being discharged by the northern Yucatan Peninsula coastal aquifer into the Gulf of Mexico, using the Sea Surface Temperature (SST) Images offshore the Yucatan coast, where we have detected a thermal anomaly that appears few hours after heavy rainfall in northern Yucatan. We associated these thermal anomalies of the SST to the groundwater being discharged into the ocean. To test our hypothesis we conducted a review of extreme rainfall events in the last 10 years; in parallel we used data from pressure and flow direction gauges installed in a known submarine groundwater discharge (SGD) to estimate the hydraulic conductivity and the quantity of groundwater being discharged. The satellite imagery and the rainfall data, allowed us to estimate the time lag between the rainfall and the SGD beginning, along with the hydraulic data from the gauges we have estimated the hydrogeological parameters of the coastal aquifer. This data is very important to contribute to the understanding the hydrogeological setting of the Yucatan coastal aquifer and its implications of the impact of human activities on the water quality. July 29th, 2005, NOAA's Sea Surface Temperature (SST) image of the Gulf of Mexico taken a week after hurricane Emily (2005). A thermal low is present offshore northern Yucatan.

  4. River Intrusion in Karst Springs in Eogenetic Aquifers: Implications for Speleogenesis

    NASA Astrophysics Data System (ADS)

    Martin, J. B.; Gulley, J.; Screaton, E. J.

    2008-12-01

    Conceptual models of speleogenesis generally assume uni-directional transport in integrated conduit systems from discrete recharge points to discharge at karst springs. Estavelles, however, are karst springs that function intermittently as discrete recharge points when river stage rises more rapidly than local aquifer heads. As river water chemistry changes between baseflow and floods, estavelles should influence mass transport through (e.g. organic carbon, nutrients, and oxygen) and speleogenesis within karst systems. Estavelles are common in our study area in north-central Florida, particularly along the lower reaches of the Santa Fe River, where it flows across the unconfined karstic Floridan aquifer. River stage in this unconfined region can rise much faster than aquifer heads when large amounts of rain fall on the confined regions in its upper reaches. Backflooding into the estavelles during elevated river stage drives river water into the ground, causing some springs to reverse and other springs to recirculate large volumes of river water. Floodwaters originating in the confined region are highly undersaturated with respect to calcite, and thus river water transitions from slightly supersaturated to highly undersaturated with respect to calcite during flood events. As a result, conduits connected to estavelles are continuously enlarged as springs reverse or recirculate calcite-undersaturated river water. It has been suggested that currently flooded caves (i.e. karst conduits) associated with springs in Florida formed entirely underwater because speleothems, which are prevalent in flooded caves in the Yucatan and Bahamas, have not been observed by cave divers. Results of this study indicate that the absence of speleothems does not necessarily provide evidence of a continuous phreatic history for underwater caves. Instead speleothems that formed in caves while dry could have been dissolved by backflooding of estavelles with undersaturated water

  5. The Hydrochemical Evolution of Water-Filled Sinkholes at Bitter Lake NWR, Roswell, NM

    NASA Astrophysics Data System (ADS)

    Premo, E.; Crossey, L. J.

    2013-12-01

    Bitter Lake National Wildlife Refuge in Roswell, NM houses one of the most ecologically significant wetlands in the US-SW including approximately 52 water-filled sinkholes each supporting a unique biological assemblage, including several endangered and endemic species (e.g., Pecos pupfish and Noel's amphipod, respectively). Forming in the karst landscape adjacent to the Pecos River where the regional dual-aquifer system discharges through a network of springs and seeps, these sinkholes are recharged by saline groundwater that is subject to anthropogenic withdrawals for irrigation and hydrocarbon production and chemically altered by a complex series of evaporation-precipitation reactions after discharge. This study investigates the hydrochemical differences among these sinkholes while considering the evolutionary processes affecting water column structure, geochemical mixing and ecological sustainability. Two major sampling suites, pre- and post-irrigation, yielded waters from 1.0m increments along the water columns of 10 representative sinkholes. Samples were analyzed for major ions, stable isotopes [δ18O, δD ], and dissolved gases; PHREEQc was used to model mineral saturation and speciation. An in-situ mineral precipitation experiment provided growth rate and mineral morphological (SEM) data. Source water is chemically similar to shallow springs found at the Refuge (Sago Spring). Sinkholes exhibit bimodal water column structure (well-mixed or stratified) organized in response to water density (with ~1.035 g/cm3 forming the modal transition threshold). By measuring the density, TDS or conductivity at sinkhole surface it is possible to predict modality of water column structure. Sinkhole waters - regardless of depth or season - fall along a common isotopic evaporation trajectory (δ D = 3.387*δ18O - 19.38), and adopt a Na-Cl chemical endmember facies. Driven primarily by physical sinkhole geometry (e.g., depth and surface area), sinkhole water follows a

  6. Functional characterization of bitter-taste receptors expressed in mammalian testis

    PubMed Central

    Xu, Jiang; Cao, Jie; Iguchi, Naoko; Riethmacher, Dieter; Huang, Liquan

    2013-01-01

    Mammalian spermatogenesis and sperm maturation are susceptible to the effects of internal and external factors. However, how male germ cells interact with and respond to these elements including those potentially toxic substances is poorly understood. Here, we show that many bitter-taste receptors (T2rs), which are believed to function as gatekeepers in the oral cavity to detect and innately prevent the ingestion of poisonous bitter-tasting compounds, are expressed in mouse seminiferous tubules. Our in situ hybridization results indicate that Tas2r transcripts are expressed postmeiotically. Functional analysis showed that mouse spermatids and spermatozoa responded to both naturally occurring and synthetic bitter-tasting compounds by increasing intracellular free calcium concentrations, and individual male germ cells exhibited different ligand-activation profiles, indicating that each cell may express a unique subset of T2r receptors. These calcium responses could be suppressed by a specific bitter-tastant blocker or abolished by the knockout of the gene for the G protein subunit α-gustducin. Taken together, our data strongly suggest that male germ cells, like taste bud cells in the oral cavity and solitary chemosensory cells in the airway, utilize T2r receptors to sense chemicals in the milieu that may affect sperm behavior and fertilization. PMID:22983952

  7. Characterization and Modulation of the Bitterness of Polymethoxyflavones Using Sensory and Receptor-Based Methods.

    PubMed

    Batenburg, A Max; de Joode, Teun; Gouka, Robin J

    2016-03-30

    An obstacle in the application of many "health ingredients" is their alleged off-flavor. We used a combination of chemical, sensory, and biological analyses to identify the bitter components in citrus peel-derived polymethoxyflavone preparations, claimed to be functional in the lowering of cholesterol. Nobiletin (56-81%) and tangeretin (10-33%) were found to be the main bitter components. Using in vitro receptor assays, hTAS2R14 was shown to be the main bitter receptor involved in their perception, with EC50 values of 14 and 63 μM, respectively. Our analysis provided several routes for off-flavor reduction. Purification is an option because a purified, single PMF species proved to be considerably less bitter upon application in emulsified foods, due to limited solubility in the aqueous phase. A second route, also demonstrated in vivo, is C5-specific demethoxylation, in line with the finding that 5-desmethylnobiletin does not activate hTAS2R14. A third route could be the use of TAS2R14 antagonists. As a proof of principle, several antagonists, with IC50 values ranging from 10 to 50 μM, were identified. PMID:26934534

  8. Individual differences in bitter taste preferences are associated with antisocial personality traits.

    PubMed

    Sagioglou, Christina; Greitemeyer, Tobias

    2016-01-01

    In two studies, we investigated how bitter taste preferences might be associated with antisocial personality traits. Two US American community samples (total N = 953; mean age = 35.65 years; 48% females) self-reported their taste preferences using two complementary preference measures and answered a number of personality questionnaires assessing Machiavellianism, psychopathy, narcissism, everyday sadism, trait aggression, and the Big Five factors of personality. The results of both studies confirmed the hypothesis that bitter taste preferences are positively associated with malevolent personality traits, with the most robust relation to everyday sadism and psychopathy. Regression analyses confirmed that this association holds when controlling for sweet, sour, and salty taste preferences and that bitter taste preferences are the overall strongest predictor compared to the other taste preferences. The data thereby provide novel insights into the relationship between personality and the ubiquitous behaviors of eating and drinking by consistently demonstrating a robust relation between increased enjoyment of bitter foods and heightened sadistic proclivities. PMID:26431683

  9. Expansion of a bitter taste receptor family in a polyphagous insect herbivore

    PubMed Central

    Xu, Wei; Papanicolaou, Alexie; Zhang, Hui-Jie; Anderson, Alisha

    2016-01-01

    The Insect taste system plays a central role in feeding behaviours and co-evolution of insect-host interactions. Gustatory receptors form the interface between the insect taste system and the environment. From genome and transcriptome sequencing we identified 197 novel gustatory receptor (GR) genes from the polyphagous pest Helicoverpa armigera. These GRs include a significantly expanded bitter receptor family (180 GRs) that could be further divided into three categories based on polypeptide lengths, gene structure and amino acid sequence. Type 1 includes 29 bitter Gr genes that possess introns. Type 2 includes 13 long intronless bitter Gr genes, while Type 3 comprises 131 short intronless bitter Gr genes. Calcium imaging analysis demonstrated that three Type 3 GRs (HarmGR35, HarmGR50 and HarmGR195) can be activated by a crude extract of cotton leaves. HarmGR195, a GR specifically and selectively expressed in adult tarsi, showed a specific response to proline, an amino acid widely present in plant tissues. We hypothesise that the expansion in the H. armigera GR family may be functionally tied to its polyphagous behavior. Understanding the molecular basis of polyphagy may provide opportunities for the development of new environmentally friendly pest control strategies. PMID:27032373

  10. Expansion of a bitter taste receptor family in a polyphagous insect herbivore.

    PubMed

    Xu, Wei; Papanicolaou, Alexie; Zhang, Hui-Jie; Anderson, Alisha

    2016-01-01

    The Insect taste system plays a central role in feeding behaviours and co-evolution of insect-host interactions. Gustatory receptors form the interface between the insect taste system and the environment. From genome and transcriptome sequencing we identified 197 novel gustatory receptor (GR) genes from the polyphagous pest Helicoverpa armigera. These GRs include a significantly expanded bitter receptor family (180 GRs) that could be further divided into three categories based on polypeptide lengths, gene structure and amino acid sequence. Type 1 includes 29 bitter Gr genes that possess introns. Type 2 includes 13 long intronless bitter Gr genes, while Type 3 comprises 131 short intronless bitter Gr genes. Calcium imaging analysis demonstrated that three Type 3 GRs (HarmGR35, HarmGR50 and HarmGR195) can be activated by a crude extract of cotton leaves. HarmGR195, a GR specifically and selectively expressed in adult tarsi, showed a specific response to proline, an amino acid widely present in plant tissues. We hypothesise that the expansion in the H. armigera GR family may be functionally tied to its polyphagous behavior. Understanding the molecular basis of polyphagy may provide opportunities for the development of new environmentally friendly pest control strategies. PMID:27032373

  11. Sweet and bitter taste in the brain of awake behaving animals.

    PubMed

    Peng, Yueqing; Gillis-Smith, Sarah; Jin, Hao; Tränkner, Dimitri; Ryba, Nicholas J P; Zuker, Charles S

    2015-11-26

    Taste is responsible for evaluating the nutritious content of food, guiding essential appetitive behaviours, preventing the ingestion of toxic substances, and helping to ensure the maintenance of a healthy diet. Sweet and bitter are two of the most salient sensory percepts for humans and other animals; sweet taste allows the identification of energy-rich nutrients whereas bitter warns against the intake of potentially noxious chemicals. In mammals, information from taste receptor cells in the tongue is transmitted through multiple neural stations to the primary gustatory cortex in the brain. Recent imaging studies have shown that sweet and bitter are represented in the primary gustatory cortex by neurons organized in a spatial map, with each taste quality encoded by distinct cortical fields. Here we demonstrate that by manipulating the brain fields representing sweet and bitter taste we directly control an animal's internal representation, sensory perception, and behavioural actions. These results substantiate the segregation of taste qualities in the cortex, expose the innate nature of appetitive and aversive taste responses, and illustrate the ability of gustatory cortex to recapitulate complex behaviours in the absence of sensory input.

  12. Assessment of bitterness intensity and suppression effects using an Electronic Tongue

    NASA Astrophysics Data System (ADS)

    Legin, A.; Rudnitskaya, A.; Kirsanov, D.; Frolova, Yu.; Clapham, D.; Caricofe, R.

    2009-05-01

    Quantification of bitterness intensity and effectivness of bitterness suppression of a novel active pharmacological ingredient (API) being developed by GSK was performed using an Electronic Tongue (ET) based on potentiometric chemical sensors. Calibration of the ET was performed with solutions of quinine hydrochloride in the concentration range 0.4-360 mgL-1. An MLR calibration model was developed for predicting bitterness intensity expressed as "equivalent quinine concentration" of a series of solutions of quinine, bittrex and the API. Additionally the effectiveness of sucralose, mixture of aspartame and acesulfame K, and grape juice in masking the bitter taste of the API was assessed using two approaches. PCA models were produced and distances between compound containing solutions and corresponding placebos were calculated. The other approach consisted in calculating "equivalent quinine concentration" using a calibration model with respect to quinine concentration. According to both methods, the most effective taste masking was produced by grape juice, followed by the mixture of aspartame and acesulfame K.

  13. Extracellular production of riboflavin-binding protein, a potential bitter inhibitor, by Brevibacillus choshinensis.

    PubMed

    Maehashi, Kenji; Matano, Mami; Saito, Makiko; Udaka, Shigezo

    2010-05-01

    Riboflavin-binding protein (RBP) is a glycophosphoprotein found in hen eggs. We previously identified the extraordinary characteristic of RBP in reducing bitterness. For a more detailed study on the mode of action and industrial application of this characteristic, we investigated the microbial production of recombinant RBP (rRBP). We constructed a chicken RBP gene expression vector by inserting the RBP cDNA in pNCMO2, the Escherichia coli-Brevibacillus choshinensis shuttle vector. B. choshinensis HPD31 transformants produced 0.8g/l of processed and unglycosylated RBP in a soluble form in the culture supernatant. However, the expressed RBP was partially dimerized and monomeric RBP was purified by two step anion-exchange and gel-filtration chromatographies. The purified rRBP elicited bitterness reduction against quinine and caffeine, although it largely lost its riboflavin-binding ability. These results indicated that glycosylation and riboflavin-binding ability are not essential for the bitterness reduction of RBP. In addition, we assessed the usefulness of the Brevibacillus system for the expression and secretion of RBP as a new type of bitterness inhibitor. PMID:20045733

  14. Sweet and bitter taste in the brain of awake behaving animals

    PubMed Central

    Peng, Yueqing; Gillis-Smith, Sarah; Jin, Hao; Tränkner, Dimitri; Ryba, Nicholas J. P.; Zuker, Charles S.

    2015-01-01

    Taste is responsible for evaluating the nutritious content of food, guiding essential appetitive behaviors, preventing the ingestion of toxic substances, and helping ensure the maintenance of a healthy diet. Sweet and bitter are two of the most salient sensory percepts for humans and other animals; sweet taste permits the identification of energy-rich nutrients while bitter warns against the intake of potentially noxious chemicals1. In mammals, information from taste receptor cells in the tongue is transmitted through multiple neural stations to the primary gustatory cortex in the brain2. Recent imaging studies have shown that sweet and bitter are represented in the primary gustatory cortex by neurons organized in a spatial map3,4, with each taste quality encoded by distinct cortical fields4. Here we demonstrate that by manipulating the brain fields representing sweet and bitter taste we directly control an animal’s internal representation, sensory perception, and behavioral actions. These results substantiate the segregation of taste qualities in the cortex, expose the innate nature of appetitive and aversive taste responses, and illustrate the ability of gustatory cortex to recapitulate complex behaviors in the absence of sensory input. PMID:26580015

  15. AFLP Analysis Provides Strategies for Improvement of Momordica Charantia L. (Bitter Gourd)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Monoecious bitter gourd (Momordica charantia L. var. minima and maxima Williams & Ng), a cucurbit of major economic importance, is widely cultivated in India, China, Africa, and South America. Although the morphology (i.e., growth habit and fruit shape, size, color and surface texture) of Indian bi...

  16. Sensory Threshold Studies of Picrocrocin, the Major Bitter Compound of Saffron.

    PubMed

    Chrysanthou, Andreas; Pouliou, Evangelia; Kyriakoudi, Anastasia; Tsimidou, Maria Z

    2016-01-01

    This study is part of a wider project on the bitter taste of saffron and its preparations. A deeper knowledge on the taste perception of picrocrocin is necessary in order to develop products that satisfy consumer senses and provide them with adequate amounts of saffron major constituents, also appreciated for bioactivity. A systematic approach on the bitterness of picrocrocin, the major responsible compound, was conducted. A panel was trained specifically for the determination of taste detection and recognition thresholds of picrocrocin, which were found to be 5.34 and 7.26 mg/L, respectively, using the Ascending Forced Choice of Limits methodology. The threshold values were examined in water in absence and presence of other saffron constituents and ethanol and were found to decrease when served hot (61 ± 4 °C). Bitterness was enhanced in 40% (v/v) aqueous ethanol. In both aqueous and ethanol extracts, the presence of saffron volatiles improved bitterness perception. The usefulness of the study was tested in the case of commercial saffron based infusions.

  17. Sweet and bitter taste in the brain of awake behaving animals.

    PubMed

    Peng, Yueqing; Gillis-Smith, Sarah; Jin, Hao; Tränkner, Dimitri; Ryba, Nicholas J P; Zuker, Charles S

    2015-11-26

    Taste is responsible for evaluating the nutritious content of food, guiding essential appetitive behaviours, preventing the ingestion of toxic substances, and helping to ensure the maintenance of a healthy diet. Sweet and bitter are two of the most salient sensory percepts for humans and other animals; sweet taste allows the identification of energy-rich nutrients whereas bitter warns against the intake of potentially noxious chemicals. In mammals, information from taste receptor cells in the tongue is transmitted through multiple neural stations to the primary gustatory cortex in the brain. Recent imaging studies have shown that sweet and bitter are represented in the primary gustatory cortex by neurons organized in a spatial map, with each taste quality encoded by distinct cortical fields. Here we demonstrate that by manipulating the brain fields representing sweet and bitter taste we directly control an animal's internal representation, sensory perception, and behavioural actions. These results substantiate the segregation of taste qualities in the cortex, expose the innate nature of appetitive and aversive taste responses, and illustrate the ability of gustatory cortex to recapitulate complex behaviours in the absence of sensory input. PMID:26580015

  18. The Cellular and Molecular Basis of Bitter Tastant-Induced Bronchodilation

    PubMed Central

    Zhang, Cheng-Hai; Lifshitz, Lawrence M.; Uy, Karl F.; Ikebe, Mitsuo; Fogarty, Kevin E.; ZhuGe, Ronghua

    2013-01-01

    Bronchodilators are a standard medicine for treating airway obstructive diseases, and β2 adrenergic receptor agonists have been the most commonly used bronchodilators since their discovery. Strikingly, activation of G-protein-coupled bitter taste receptors (TAS2Rs) in airway smooth muscle (ASM) causes a stronger bronchodilation in vitro and in vivo than β2 agonists, implying that new and better bronchodilators could be developed. A critical step towards realizing this potential is to understand the mechanisms underlying this bronchodilation, which remain ill-defined. An influential hypothesis argues that bitter tastants generate localized Ca2+ signals, as revealed in cultured ASM cells, to activate large-conductance Ca2+-activated K+ channels, which in turn hyperpolarize the membrane, leading to relaxation. Here we report that in mouse primary ASM cells bitter tastants neither evoke localized Ca2+ events nor alter spontaneous local Ca2+ transients. Interestingly, they increase global intracellular [Ca2+]i, although to a much lower level than bronchoconstrictors. We show that these Ca2+ changes in cells at rest are mediated via activation of the canonical bitter taste signaling cascade (i.e., TAS2R-gustducin-phospholipase Cβ [PLCβ]- inositol 1,4,5-triphosphate receptor [IP3R]), and are not sufficient to impact airway contractility. But activation of TAS2Rs fully reverses the increase in [Ca2+]i induced by bronchoconstrictors, and this lowering of the [Ca2+]i is necessary for bitter tastant-induced ASM cell relaxation. We further show that bitter tastants inhibit L-type voltage-dependent Ca2+ channels (VDCCs), resulting in reversal in [Ca2+]i, and this inhibition can be prevented by pertussis toxin and G-protein βγ subunit inhibitors, but not by the blockers of PLCβ and IP3R. Together, we suggest that TAS2R stimulation activates two opposing Ca2+ signaling pathways via Gβγ to increase [Ca2+]i at rest while blocking activated L-type VDCCs to induce

  19. Ability of Food/Drink to Reduce the Bitterness Intensity of Topiramate as Determined by Taste Sensor Analysis.

    PubMed

    Haraguchi, Tamami; Uchida, Takahiro; Hazekawa, Mai; Yoshida, Miyako; Nakashima, Masaki; Sanda, Hotaka; Hase, Takema; Tomoda, Yutaka

    2016-01-01

    The purpose of this study was to determine which foods and/or drinks are capable of reducing the bitterness of topiramate when consumed together with the medicine. The inhibitory effects of foods/drinks (yoghurt and nine other foods/drinks) on the bitterness of topiramate (5 mg/mL) were evaluated with a taste sensor using a bitterness-responsive membrane (C00). The effect of topiramate on the taste characteristics of the foods/drinks themselves was also evaluated by taste sensor outputs. The viscosities of the foods/drinks and the influence of the lactic acid and orotic acid components of yoghurt, the most successful of the tested substances in taste masking, on the bitterness of topiramate were also measured. Yoghurt was predicted to be the most effective of the foods/drinks tested in reducing the acidic bitterness-responsive sensor output of topiramate. The outputs of the astringency sensor, sourness sensor, and saltiness sensor to yoghurt were not reduced by the addition of topiramate. The viscosity and lactic acid and orotic acid components of yoghurt seemed to be the keys in reducing the bitterness of topiramate. Yoghurt is predicted to be the food/drink most capable of reducing the bitterness of topiramate without losing the taste of the food/drink itself.

  20. Geoarchaeology of the karstic area of Mirambello, North-East Crete (Greece): palaeoenvironmental investigations and human settlement implications

    NASA Astrophysics Data System (ADS)

    Ghilardi, M.; Kunesch, S.; Robert, V.; Farnoux, A.; Wurmser, H.

    2009-04-01

    The present work aims to detail the preliminary researches dealing with the geomorphologic, topographic and archaeological setting from two major settlements located in north east Crete. The project undertook by the French school of Archaeology in Athens aims to reconstruct the palaeoenvironmental evolution of the whole area during the last millennia. Fieldworks, including coring, had already been done in August 2006, April 2007 and September 2008; we propose to present the main results. The settlements of Latô and Dreros belong to the area of Mirambello characterized by its spectacular karstic processes and landforms, different karstic depressions with different size can be identified and classified into Dolines and Poljés. As far as the archaeological interest is concerned, villages and cities were occupied during the hellenestic period; several remains are still present around and inside these depressions. Using a G.I.S., the first step consisted in establishing a local geomorphological mapping, taking into account the geological background and the historical occupation of the area. The second step consisted in establishing topographic cross sections of the doline, where the ancient settlement of Latô is located, based on various DGPS surveys. Several questions concerning the occupation of this depression arose : how and for which reasons people decided to leave close to this specific landform ? Which type of activities (farming, grazing, cultivation…) existed and did they were related with natural resources exploitation ? A project associating the local greek archaeological services (Ephoria of Aghios Nikolaos, Director Ms. Apostolakou), the mayor of Nea Polis, the University of Paris 12 (GEONAT EA 435) and the French School of Athens tries to depict the historical evolution of the landscape. Four boreholes (up to a maximum depth of 5 meters) had been drilled in the poljé of Dreros and in a doline situated 1 km away from the ancient settlement of Lat

  1. Human Impact on Biogeochemical Cycles and Deposition Dynamics in Karstic Lakes: El Tobar Lake Record (Central Iberian Range, Spain)

    NASA Astrophysics Data System (ADS)

    Barreiro-Lostres, F.; Moreno-Caballud, A.; Giralt, S.; Hillman, A. L.; Brown, E. T.; Abbott, M. B.; Valero-Garces, B. L.

    2014-12-01

    Karstic lakes in the Iberian Range (Central Spain) provide a unique opportunity to test the human impact in the watersheds and the aquatic environments during historical times. We reconstruct the depositional evolution and the changes in biogeochemical cycles of El Tobar karstic lake, evaluating the response and the resilience of this Mediterranean ecosystem to both anthropogenic impacts and climate forcing during the last 1000 years. Lake El Tobar (40°32'N, 3°56'W; 1200 m a.s.l.; see Figure), 16 ha surface area, 20 m max. depth and permanent meromictic conditions, has a relatively large watershed (1080 ha). Five 8 m long sediment cores and short gravity cores where recovered, imaged, logged with a Geotek, described and sampled for geochemical analyses (elemental TOC, TIC, TN, TS), XRF scanner and ICP-MS, and dated (137Cs and 10 14C assays). The record is a combination of: i) laminated dark silts with terrestrial remains and diatoms and ii) massive to banded light silts (mm to cm -thick layers) interpreted as flood deposits. Sediments, TOC, and Br/Ti and Sr/Ca ratios identify four periods of increased sediment delivery occurred about 1500, 1800, 1850 and 1900 AD, coinciding with large land uses changes of regional relevance such as land clearing and increased population. Two main hydrological changes are clearly recorded in El Tobar sequence. The first one, marked by a sharp decrease in Mg, Ca and Si concentrations, took place about 1200 AD, and during a period of increasing lake level, which shifted from shallower to deeper facies and from carbonatic to clastic and organic-rich deposition. This change was likely related to increased water availability synchronous to the transition from the Medieval Climate Anomaly to the Little Ice Age. The second one was a canal construction in 1967 AD when a nearby reservoir provided fresh water influx to the lake, and resulted in stronger meromictic conditions in the system after canal construction, which is marked by lower

  2. Effects of precipitation events on colloids in a karst aquifer

    NASA Astrophysics Data System (ADS)

    Shevenell, Lisa; McCarthy, John F.

    2002-01-01

    The effects of precipitation events on colloid mobilization were evaluated during several storms from six wells in a karstic aquifer at the Oak Ridge Y-12 Plant in eastern Tennessee (USA). Turbidity increases and rapidly recedes following rain events. Although the magnitude of the turbidity increases are relatively small (≤4.78 NTU), the increased turbidity suggests transient increases in colloid abundance during storm versus non-storm periods. During the larger storms (>19 mm), the increased turbidity is associated with increases in pH, total organic carbon (TOC) and temperature, and with decreases in dissolved oxygen (DO). These larger storms result in flushing of a greater proportion of higher pH, TOC (and lower DO) soil or matrix waters into the fractures and conduits than occurs during smaller storms. Smaller storms also result in increases in turbidity, but show increases in DO and decreases in pH reflecting less influence on the water chemistry from the longer residence time epikarst or and matrix waters, and greater impact from the more dilute, newly recharged waters. Due to the complexity of karst flow and temporal variations in flow and chemistry, controls on turbidity are not consistent through time and space at the wells. During smaller storms, recharge by lower ionic strength waters may promote colloid release and thus contribute to observed increases in turbidity. During larger storms, elevated turbidity may be more related to pH increases resulting from greater influx of matrix and soil waters into fractures and conduits. Chemical factors alone cannot account for the changes in turbidity observed during the various storms. Because of the complicated nature of flow and particle transport in karst aquifers, the presence of colloids during precipitation events is dictated by a complex interplay of chemical reactions and the effects of physical perturbations due to increased flow through the conduits and fractures. Simple trends in water quality

  3. Particles in a karstic spring, Swabian Alb: Physicochemical and hydraulic effects during a snow melt event.

    NASA Astrophysics Data System (ADS)

    Schiperski, Ferry; Zirlewagen, Johannes; Hillebrand, Olav; Scheytt, Traugott; Licha, Tobias

    2013-04-01

    The studied karst spring 'Gallusquelle' is located on the Swabian Alb in Southwest Germany. The catchment area of the 'Gallusquelle' measures about 45 km². An average annual discharge of 0.5 m³/s serves drinking water to about 40,000 people via a waterworks. The study is part of the research project 'AGRO' (www.projekt-agro.de). The main objective of the project 'AGRO' is to develop a tool for the process-based risk management of micropollutants and pathogens in rural karst aquifers on catchment scale. As particle related transport could play an important role for micropollutants and pathogens, the characterization of particles in the spring water is one focus of this work. Furthermore we will attempt to correlate physicochemical parameters with the characteristics of particles in the spring water in order to enhance the knowledge of the transport mechanisms within the karst aquifer. For the measurement of the particle concentration and the particle size distribution the CIS 1 (GALAI) was used. The system works in a range of 0.5 to 150 µm with a resolution of at least 0.5 µm. The measurement is based on time-of-transition method using a laser beam. The turbidity was measured with an ULTRATURB PLUS (DR.LANGE) and a Fluorometer (GGUN-FL30, ALBILLIA), both working with scattering light method. To verify these measurements we used a portable turbidimeter (2100P IS PORTABLE TURBIDIMETER, HACH) working with the ratio of the signals from the scattered and the transmitted light. Temperature and electrical conductivity where also measured with the GGUN-FL30, whereby the electrical conductivity was verified with a portable multimeter (HQ 40D, HACH). Discharge, pH, water hardness, anion- and cation concentration, total organic carbon (TOC) and dissolved organic carbon (DOC) were also determined. To characterize the particles, the spring water was filtered onsite and the filter cake was analyzed in the laboratory. For SEM (scanning electron microscopy) including EDAX

  4. Amino Acid Derivatives as Bitter Taste Receptor (T2R) Blockers*

    PubMed Central

    Pydi, Sai P.; Sobotkiewicz, Tyler; Billakanti, Rohini; Bhullar, Rajinder P.; Loewen, Michele C.; Chelikani, Prashen

    2014-01-01

    In humans, the 25 bitter taste receptors (T2Rs) are activated by hundreds of structurally diverse bitter compounds. However, only five antagonists or bitter blockers are known. In this study, using molecular modeling guided site-directed mutagenesis, we elucidated the ligand-binding pocket of T2R4. We found seven amino acids located in the extracellular side of transmembrane 3 (TM3), TM4, extracellular loop 2 (ECL2), and ECL3 to be involved in T2R4 binding to its agonist quinine. ECL2 residues Asn-173 and Thr-174 are essential for quinine binding. Guided by a molecular model of T2R4, a number of amino acid derivatives were screened for their ability to bind to T2R4. These predictions were tested by calcium imaging assays that led to identification of γ-aminobutryic acid (GABA) and Nα,Nα-bis(carboxymethyl)-l-lysine (BCML) as competitive inhibitors of quinine-activated T2R4 with an IC50 of 3.2 ± 0.3 μm and 59 ± 18 nm, respectively. Interestingly, pharmacological characterization using a constitutively active mutant of T2R4 reveals that GABA acts as an antagonist, whereas BCML acts as an inverse agonist on T2R4. Site-directed mutagenesis confirms that the two novel bitter blockers share the same orthosteric site as the agonist quinine. The signature residues Ala-90 and Lys-270 play important roles in interacting with BCML and GABA, respectively. This is the first report to characterize a T2R endogenous antagonist and an inverse agonist. The novel bitter blockers will facilitate physiological studies focused on understanding the roles of T2Rs in extraoral tissues. PMID:25059668

  5. Recombinant yeast as a functional tool for understanding bitterness and cucurbitacin biosynthesis in watermelon (Citrullus spp.).

    PubMed

    Davidovich-Rikanati, Rachel; Shalev, Lior; Baranes, Nadine; Meir, Ayala; Itkin, Maxim; Cohen, Shahar; Zimbler, Kobi; Portnoy, Vitaly; Ebizuka, Yutaka; Shibuya, Masaaki; Burger, Yosef; Katzir, Nurit; Schaffer, Arthur A; Lewinsohn, Efraim; Tadmor, Ya'akov

    2015-01-01

    Cucurbitacins are a group of bitter-tasting oxygenated tetracyclic triterpenes that are produced in the family Cucurbitaceae and other plant families. The natural roles of cucurbitacins in plants are probably related to defence against pathogens and pests. Cucurbitadienol, a triterpene synthesized from oxidosqualene, is the first committed precursor to cucurbitacins produced by a specialized oxidosqualene cyclase termed cucurbitadienol synthase. We explored cucurbitacin accumulation in watermelon in relation to bitterness. Our findings show that cucurbitacins are accumulated in bitter-tasting watermelon, Citrullus lanatus var. citroides, as well as in their wild ancestor, C. colocynthis, but not in non-bitter commercial cultivars of sweet watermelon (C. lanatus var. lanatus). Molecular analysis of genes expressed in the roots of several watermelon accessions led to the isolation of three sequences (CcCDS1, CcCDS2 and ClCDS1), all displaying high similarity to the pumpkin CpCPQ, encoding a protein previously shown to possess cucurbitadienol synthase activity. We utilized the Saccharomyces cerevisiae strain BY4743, heterozygous for lanosterol synthase, to probe for possible encoded cucurbitadienol synthase activity of the expressed watermelon sequences. Functional expression of the two sequences isolated from C. colocynthis (CcCDS1 and CcCDS2) in yeast revealed that only CcCDS2 possessed cucurbitadienol synthase activity, while CcCDS1 did not display cucurbitadienol synthase activity in recombinant yeast. ClCDS1 isolated from C. lanatus var. lanatus is almost identical to CcCDS1. Our results imply that CcCDS2 plays a role in imparting bitterness to watermelon. Yeast has been an excellent diagnostic tool to determine the first committed step of cucurbitacin biosynthesis in watermelon.

  6. Smallest bitter taste receptor (T2Rs) gene repertoire in carnivores.

    PubMed

    Hu, Ling-Ling; Shi, Peng

    2013-06-01

    Bitter taste reception is presumably associated with dietary selection, preventing animals from ingesting potentially harmful compounds. Accordingly, carnivores, who encounter these toxic substances less often, should have fewer genes associated with bitter taste reception compared with herbivores and omnivores. To investigate the genetic basis of bitter taste reception, we confirmed bitter taste receptor (T2R) genes previously found in the genome sequences of two herbivores (cow and horse), two omnivores (mouse and rat) and one carnivore (dog). We also identified, for the first time, the T2R repertoire from the genome of other four carnivore species (ferret, giant panda, polar bear and cat) and detected 17-20 bitter receptor genes from the five carnivore genomes, including 12-16 intact genes, 0-1 partial but putatively functional genes, and 3-8 pseudogenes. Both the intact T2R genes and the total T2R gene number among carnivores were the smallest among the tested species, supporting earlier speculations that carnivores have fewer T2R genes, herbivores an intermediate number, and omnivores the largest T2R gene repertoire. To further explain the genetic basis for this disparity, we constructed a phylogenetic tree, which showed most of the T2R genes from the five carnivores were one-to-one orthologs across the tree, suggesting that carnivore T2Rs were conserved among mammals. Similarly, the small carnivore T2R family size was likely due to rare duplication events. Collectively, these results strengthen arguments for the connection between T2R gene family size, diet and habit. PMID:23776004

  7. Smallest bitter taste receptor (T2Rs) gene repertoire in carnivores.

    PubMed

    Hu, Ling-Ling; Shi, Peng

    2013-06-01

    Bitter taste reception is presumably associated with dietary selection, preventing animals from ingesting potentially harmful compounds. Accordingly, carnivores, who encounter these toxic substances less often, should have fewer genes associated with bitter taste reception compared with herbivores and omnivores. To investigate the genetic basis of bitter taste reception, we confirmed bitter taste receptor (T2R) genes previously found in the genome sequences of two herbivores (cow and horse), two omnivores (mouse and rat) and one carnivore (dog). We also identified, for the first time, the T2R repertoire from the genome of other four carnivore species (ferret, giant panda, polar bear and cat) and detected 17-20 bitter receptor genes from the five carnivore genomes, including 12-16 intact genes, 0-1 partial but putatively functional genes, and 3-8 pseudogenes. Both the intact T2R genes and the total T2R gene number among carnivores were the smallest among the tested species, supporting earlier speculations that carnivores have fewer T2R genes, herbivores an intermediate number, and omnivores the largest T2R gene repertoire. To further explain the genetic basis for this disparity, we constructed a phylogenetic tree, which showed most of the T2R genes from the five carnivores were one-to-one orthologs across the tree, suggesting that carnivore T2Rs were conserved among mammals. Similarly, the small carnivore T2R family size was likely due to rare duplication events. Collectively, these results strengthen arguments for the connection between T2R gene family size, diet and habit.

  8. Recombinant yeast as a functional tool for understanding bitterness and cucurbitacin biosynthesis in watermelon (Citrullus spp.).

    PubMed

    Davidovich-Rikanati, Rachel; Shalev, Lior; Baranes, Nadine; Meir, Ayala; Itkin, Maxim; Cohen, Shahar; Zimbler, Kobi; Portnoy, Vitaly; Ebizuka, Yutaka; Shibuya, Masaaki; Burger, Yosef; Katzir, Nurit; Schaffer, Arthur A; Lewinsohn, Efraim; Tadmor, Ya'akov

    2015-01-01

    Cucurbitacins are a group of bitter-tasting oxygenated tetracyclic triterpenes that are produced in the family Cucurbitaceae and other plant families. The natural roles of cucurbitacins in plants are probably related to defence against pathogens and pests. Cucurbitadienol, a triterpene synthesized from oxidosqualene, is the first committed precursor to cucurbitacins produced by a specialized oxidosqualene cyclase termed cucurbitadienol synthase. We explored cucurbitacin accumulation in watermelon in relation to bitterness. Our findings show that cucurbitacins are accumulated in bitter-tasting watermelon, Citrullus lanatus var. citroides, as well as in their wild ancestor, C. colocynthis, but not in non-bitter commercial cultivars of sweet watermelon (C. lanatus var. lanatus). Molecular analysis of genes expressed in the roots of several watermelon accessions led to the isolation of three sequences (CcCDS1, CcCDS2 and ClCDS1), all displaying high similarity to the pumpkin CpCPQ, encoding a protein previously shown to possess cucurbitadienol synthase activity. We utilized the Saccharomyces cerevisiae strain BY4743, heterozygous for lanosterol synthase, to probe for possible encoded cucurbitadienol synthase activity of the expressed watermelon sequences. Functional expression of the two sequences isolated from C. colocynthis (CcCDS1 and CcCDS2) in yeast revealed that only CcCDS2 possessed cucurbitadienol synthase activity, while CcCDS1 did not display cucurbitadienol synthase activity in recombinant yeast. ClCDS1 isolated from C. lanatus var. lanatus is almost identical to CcCDS1. Our results imply that CcCDS2 plays a role in imparting bitterness to watermelon. Yeast has been an excellent diagnostic tool to determine the first committed step of cucurbitacin biosynthesis in watermelon. PMID:25308777

  9. A heteromeric membrane-bound prenyltransferase complex from hop catalyzes three sequential aromatic prenylations in the bitter acid pathway.

    PubMed

    Li, Haoxun; Ban, Zhaonan; Qin, Hao; Ma, Liya; King, Andrew J; Wang, Guodong

    2015-03-01

    Bitter acids (α and β types) account for more than 30% of the fresh weight of hop (Humulus lupulus) glandular trichomes and are well known for their contribution to the bitter taste of beer. These multiprenylated chemicals also show diverse biological activities, some of which have potential benefits to human health. The bitter acid biosynthetic pathway has been investigated extensively, and the genes for the early steps of bitter acid synthesis have been cloned and functionally characterized. However, little is known about the enzyme(s) that catalyze three sequential prenylation steps in the β-bitter acid pathway. Here, we employed a yeast (Saccharomyces cerevisiae) system for the functional identification of aromatic prenyltransferase (PT) genes. Two PT genes (HlPT1L and HlPT2) obtained from a hop trichome-specific complementary DNA library were functionally characterized using this yeast system. Coexpression of codon-optimized PT1L and PT2 in yeast, together with upstream genes, led to the production of bitter acids, but no bitter acids were detected when either of the PT genes was expressed by itself. Stepwise mutation of the aspartate-rich motifs in PT1L and PT2 further revealed the prenylation sequence of these two enzymes in β-bitter acid biosynthesis: PT1L catalyzed only the first prenylation step, and PT2 catalyzed the two subsequent prenylation steps. A metabolon formed through interactions between PT1L and PT2 was demonstrated using a yeast two-hybrid system, reciprocal coimmunoprecipitation, and in vitro biochemical assays. These results provide direct evidence of the involvement of a functional metabolon of membrane-bound prenyltransferases in bitter acid biosynthesis in hop. PMID:25564559

  10. Mechanisms of cancer chemoprevention by hop bitter acids (beer aroma) through induction of apoptosis mediated by Fas and caspase cascades.

    PubMed

    Chen, Wei-Jen; Lin, Jen-Kun

    2004-01-14

    The bitter acids of hops (Humulus lupulus L.) mainly consist of alpha-acids, beta-acids, and their oxidation products that contribute the unique aroma of the beer beverage. Hop bitter acids displayed a strong growth inhibitory effect against human leukemia HL-60 cells, with an estimated IC(50) value of 8.67 microg/mL, but were less effective against human histolytic lymphoma U937 cells. Induction of apoptosis was confirmed in HL-60 cells by DNA fragmentation and the appearance of a sub-G1 DNA peak, which were preceded by dissipation of mitochondrial membrane potential, cytochrome c release, and subsequent induction of pro-caspase-9 and -3 processing. Cleavages of PARP and DFF-45 were accompanied with activation of caspase-9 and -3 triggered by hop bitter acids in HL-60 cells. The change in the expression of Bcl-2, Bcl-X(L), and Bax in response to hop bitter acids was studied, and the Bcl-2 protein level slightly decreased; however, the Bcl-X(L) protein level was obviously decreased, whereas the Bax protein level was dramatically increased, indicating that the control of Bcl-2 family proteins by hop bitter acids might participate in the disruption of mitochondrial integrity. In addition, the results showed that hop bitter acids promoted the up-regulation of Fas and FasL prior to the processing and activation of pro-caspase-8 and cleavage of Bid, suggesting the involvement of a Fas-mediated pathway in hop bitter acids-induced cells. Taken together, these findings suggest that a certain intimate link might exist between receptor- and mitochondria-mediated death signalings that committed to cell death induced by hop bitter acids. The induction of apoptosis by hop bitter acids may offer a pivotal mechanism for their chemopreventive action.

  11. The combination effect of L-arginine and NaCl on bitterness suppression of amino acid solutions.

    PubMed

    Ogawa, Tazuko; Nakamura, Tomoko; Tsuji, Eriko; Miyanaga, Yohko; Nakagawa, Hiroyo; Hirabayashi, Hitomi; Uchida, Takahiro

    2004-02-01

    The purpose of the present study was to quantify the degree of suppression of the bitterness of two amino acids (L-isoleucine (L-Ile), and L-phenylalanine (L-Phe)) which could be achieved by the addition of various test chemicals, and to examine the mechanism of this bitterness suppression. The test chemicals used were two sweeteners (sucrose, aspartame), NaCl, various acidic (L-aspartic acid, L-glutamic acid), or basic (L-histidine, L-lysine and L-arginine) amino acids, tannic acid and phosphatidic acid. The combination of L-arginine (L-Arg) and NaCl together was the most effective in reducing the bitterness of 100 mM L-Ile and L-Phe solutions in human gustatory sensation tests. Even in bitterness of 0.1 mM quinine solution, L-Arg was also successful in reducing the bitterness. This bitterness-suppression effect was specific to L-Arg and not to the other basic amino acids. No comparable taste-masking effect was observed for the acidic amino acids. The artificial taste sensor failed to predict completely the bitterness-suppressing effect of L-Arg. It seems likely that the bitterness-suppressing effect of L-Arg is mediated not only by binding at the receptor site, but also elsewhere in the process of bitterness perception, such as a direct effect on the sodium channel. It is conjectured that the guanidinium group of L-Arg may interact with sodium channels in taste bud membranes.

  12. 40 CFR 147.2102 - Aquifer exemptions.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 24 2013-07-01 2013-07-01 false Aquifer exemptions. 147.2102 Section....2102 Aquifer exemptions. (a) This section identifies any aquifers or their portions exempted in... future exempt other aquifers or their portions, according to applicable procedures, without...

  13. 40 CFR 147.2102 - Aquifer exemptions.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 23 2011-07-01 2011-07-01 false Aquifer exemptions. 147.2102 Section....2102 Aquifer exemptions. (a) This section identifies any aquifers or their portions exempted in... future exempt other aquifers or their portions, according to applicable procedures, without...

  14. 40 CFR 147.1952 - Aquifer exemptions.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 24 2012-07-01 2012-07-01 false Aquifer exemptions. 147.1952 Section....1952 Aquifer exemptions. (a) This section identifies any aquifers or their portions exempted in... future exempt other aquifers or portions, according to applicable procedures, without codifying...

  15. 40 CFR 147.3003 - Aquifer exemptions.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 24 2013-07-01 2013-07-01 false Aquifer exemptions. 147.3003 Section..., Ute Mountain Ute, and All Other New Mexico Tribes § 147.3003 Aquifer exemptions. (a) Aquifer... described in appendix A are hereby exempted. The exempted aquifers are defined by a one-quarter mile...

  16. 40 CFR 147.3003 - Aquifer exemptions.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 22 2010-07-01 2010-07-01 false Aquifer exemptions. 147.3003 Section..., Ute Mountain Ute, and All Other New Mexico Tribes § 147.3003 Aquifer exemptions. (a) Aquifer... described in appendix A are hereby exempted. The exempted aquifers are defined by a one-quarter mile...

  17. 40 CFR 147.302 - Aquifer exemptions.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 23 2011-07-01 2011-07-01 false Aquifer exemptions. 147.302 Section... Aquifer exemptions. (a) This section identifies any aquifers of their portions exempted in accordance with... other aquifers or portions according to applicable procedures without codifying such exemptions in...

  18. 40 CFR 147.302 - Aquifer exemptions.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 23 2014-07-01 2014-07-01 false Aquifer exemptions. 147.302 Section... Aquifer exemptions. (a) This section identifies any aquifers of their portions exempted in accordance with... other aquifers or portions according to applicable procedures without codifying such exemptions in...

  19. 40 CFR 147.2102 - Aquifer exemptions.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 23 2014-07-01 2014-07-01 false Aquifer exemptions. 147.2102 Section....2102 Aquifer exemptions. (a) This section identifies any aquifers or their portions exempted in... future exempt other aquifers or their portions, according to applicable procedures, without...

  20. 40 CFR 147.1952 - Aquifer exemptions.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 23 2011-07-01 2011-07-01 false Aquifer exemptions. 147.1952 Section....1952 Aquifer exemptions. (a) This section identifies any aquifers or their portions exempted in... future exempt other aquifers or portions, according to applicable procedures, without codifying...

  1. 40 CFR 147.2554 - Aquifer exemptions.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 22 2010-07-01 2010-07-01 false Aquifer exemptions. 147.2554 Section... Aquifer exemptions. In accordance with §§ 144.7(b) and 146.4 of this chapter, those portions of aquifers... injection activity. This exemption applies only to the aquifers tabulated below, and includes those...

  2. 40 CFR 147.1952 - Aquifer exemptions.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 24 2013-07-01 2013-07-01 false Aquifer exemptions. 147.1952 Section....1952 Aquifer exemptions. (a) This section identifies any aquifers or their portions exempted in... future exempt other aquifers or portions, according to applicable procedures, without codifying...

  3. 40 CFR 147.1652 - Aquifer exemptions.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 22 2010-07-01 2010-07-01 false Aquifer exemptions. 147.1652 Section... Aquifer exemptions. (a) This section identifies any aquifer or their portions exempted in accordance with... other aquifers or portions, according to applicable procedures, without codifying such exemptions...

  4. 40 CFR 147.1652 - Aquifer exemptions.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 23 2011-07-01 2011-07-01 false Aquifer exemptions. 147.1652 Section... Aquifer exemptions. (a) This section identifies any aquifer or their portions exempted in accordance with... other aquifers or portions, according to applicable procedures, without codifying such exemptions...

  5. 40 CFR 147.302 - Aquifer exemptions.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 24 2013-07-01 2013-07-01 false Aquifer exemptions. 147.302 Section... Aquifer exemptions. (a) This section identifies any aquifers of their portions exempted in accordance with... other aquifers or portions according to applicable procedures without codifying such exemptions in...

  6. 40 CFR 147.102 - Aquifer exemptions.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 23 2011-07-01 2011-07-01 false Aquifer exemptions. 147.102 Section... Aquifer exemptions. (a) This section identifies any aquifers or their portions exempted in accordance with... other aquifers or portions, according to applicable procedures, without codifying such exemptions...

  7. 40 CFR 147.3003 - Aquifer exemptions.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 23 2011-07-01 2011-07-01 false Aquifer exemptions. 147.3003 Section..., Ute Mountain Ute, and All Other New Mexico Tribes § 147.3003 Aquifer exemptions. (a) Aquifer... described in appendix A are hereby exempted. The exempted aquifers are defined by a one-quarter mile...

  8. 40 CFR 147.2102 - Aquifer exemptions.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 24 2012-07-01 2012-07-01 false Aquifer exemptions. 147.2102 Section....2102 Aquifer exemptions. (a) This section identifies any aquifers or their portions exempted in... future exempt other aquifers or their portions, according to applicable procedures, without...

  9. 40 CFR 147.302 - Aquifer exemptions.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 22 2010-07-01 2010-07-01 false Aquifer exemptions. 147.302 Section... Aquifer exemptions. (a) This section identifies any aquifers of their portions exempted in accordance with... other aquifers or portions according to applicable procedures without codifying such exemptions in...

  10. 40 CFR 147.1952 - Aquifer exemptions.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 23 2014-07-01 2014-07-01 false Aquifer exemptions. 147.1952 Section....1952 Aquifer exemptions. (a) This section identifies any aquifers or their portions exempted in... future exempt other aquifers or portions, according to applicable procedures, without codifying...

  11. 40 CFR 147.2554 - Aquifer exemptions.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 23 2011-07-01 2011-07-01 false Aquifer exemptions. 147.2554 Section... Aquifer exemptions. In accordance with §§ 144.7(b) and 146.4 of this chapter, those portions of aquifers... injection activity. This exemption applies only to the aquifers tabulated below, and includes those...

  12. 40 CFR 147.3003 - Aquifer exemptions.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 23 2014-07-01 2014-07-01 false Aquifer exemptions. 147.3003 Section..., Ute Mountain Ute, and All Other New Mexico Tribes § 147.3003 Aquifer exemptions. (a) Aquifer... described in appendix A are hereby exempted. The exempted aquifers are defined by a one-quarter mile...

  13. 40 CFR 147.102 - Aquifer exemptions.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 24 2013-07-01 2013-07-01 false Aquifer exemptions. 147.102 Section... Aquifer exemptions. (a) This section identifies any aquifers or their portions exempted in accordance with... other aquifers or portions, according to applicable procedures, without codifying such exemptions...

  14. 40 CFR 147.2102 - Aquifer exemptions.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 22 2010-07-01 2010-07-01 false Aquifer exemptions. 147.2102 Section....2102 Aquifer exemptions. (a) This section identifies any aquifers or their portions exempted in... future exempt other aquifers or their portions, according to applicable procedures, without...

  15. 40 CFR 147.1952 - Aquifer exemptions.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 22 2010-07-01 2010-07-01 false Aquifer exemptions. 147.1952 Section....1952 Aquifer exemptions. (a) This section identifies any aquifers or their portions exempted in... future exempt other aquifers or portions, according to applicable procedures, without codifying...

  16. 40 CFR 147.1652 - Aquifer exemptions.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 23 2014-07-01 2014-07-01 false Aquifer exemptions. 147.1652 Section... Aquifer exemptions. (a) This section identifies any aquifer or their portions exempted in accordance with... other aquifers or portions, according to applicable procedures, without codifying such exemptions...

  17. 40 CFR 147.2554 - Aquifer exemptions.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 23 2014-07-01 2014-07-01 false Aquifer exemptions. 147.2554 Section... Aquifer exemptions. In accordance with §§ 144.7(b) and 146.4 of this chapter, those portions of aquifers... injection activity. This exemption applies only to the aquifers tabulated below, and includes those...

  18. 40 CFR 147.1652 - Aquifer exemptions.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 24 2012-07-01 2012-07-01 false Aquifer exemptions. 147.1652 Section... Aquifer exemptions. (a) This section identifies any aquifer or their portions exempted in accordance with... other aquifers or portions, according to applicable procedures, without codifying such exemptions...

  19. 40 CFR 147.2554 - Aquifer exemptions.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 24 2012-07-01 2012-07-01 false Aquifer exemptions. 147.2554 Section... Aquifer exemptions. In accordance with §§ 144.7(b) and 146.4 of this chapter, those portions of aquifers... injection activity. This exemption applies only to the aquifers tabulated below, and includes those...

  20. 40 CFR 147.1652 - Aquifer exemptions.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 24 2013-07-01 2013-07-01 false Aquifer exemptions. 147.1652 Section... Aquifer exemptions. (a) This section identifies any aquifer or their portions exempted in accordance with... other aquifers or portions, according to applicable procedures, without codifying such exemptions...

  1. 40 CFR 147.302 - Aquifer exemptions.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 24 2012-07-01 2012-07-01 false Aquifer exemptions. 147.302 Section... Aquifer exemptions. (a) This section identifies any aquifers of their portions exempted in accordance with... other aquifers or portions according to applicable procedures without codifying such exemptions in...

  2. 40 CFR 147.2554 - Aquifer exemptions.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 24 2013-07-01 2013-07-01 false Aquifer exemptions. 147.2554 Section... Aquifer exemptions. In accordance with §§ 144.7(b) and 146.4 of this chapter, those portions of aquifers... injection activity. This exemption applies only to the aquifers tabulated below, and includes those...

  3. 40 CFR 147.102 - Aquifer exemptions.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 22 2010-07-01 2010-07-01 false Aquifer exemptions. 147.102 Section... Aquifer exemptions. (a) This section identifies any aquifers or their portions exempted in accordance with... other aquifers or portions, according to applicable procedures, without codifying such exemptions...

  4. 40 CFR 147.102 - Aquifer exemptions.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 23 2014-07-01 2014-07-01 false Aquifer exemptions. 147.102 Section... Aquifer exemptions. (a) This section identifies any aquifers or their portions exempted in accordance with... other aquifers or portions, according to applicable procedures, without codifying such exemptions...

  5. 40 CFR 147.3003 - Aquifer exemptions.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 24 2012-07-01 2012-07-01 false Aquifer exemptions. 147.3003 Section..., Ute Mountain Ute, and All Other New Mexico Tribes § 147.3003 Aquifer exemptions. (a) Aquifer... described in appendix A are hereby exempted. The exempted aquifers are defined by a one-quarter mile...

  6. 40 CFR 147.102 - Aquifer exemptions.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 24 2012-07-01 2012-07-01 false Aquifer exemptions. 147.102 Section... Aquifer exemptions. (a) This section identifies any aquifers or their portions exempted in accordance with... other aquifers or portions, according to applicable procedures, without codifying such exemptions...

  7. Characteristics of subtropic karstic Dinaride Lake in its unstable geothectonic regime

    NASA Astrophysics Data System (ADS)

    Krstic, N.

    2009-04-01

    Geotectonic evolution of Dinarides started in Mid-Cretaceous, when this part of African Plate approached Stable Europe. Geodynamic style is as follow: "subduction-termination / colision (Paleocene / Eocene), collision (Eocene), postcollision / colapse (Oligocene / early Miocene)" (Cvetković et al., 2004). Longlasting melting of lower crust (ibid: fig. 11). "The gravity colapse of the Dinaride orogen is inferred from the faulth pattern and shape" as mirrored in sedimetary record of lacustrine basin (ibid). So, at the turn from Paleogene to Neogene on Dinarides was formed large subtropical karstic system of lakes. Another part of Africa is the Adriatic Plate mowing northwards under the Alps (Schmid et al., 2006: fig. 1 and there in). Two coal seams (brown coal and lignite), formed during colateral catastrofic earthquakes, indicate two main phases of tectonic push of Adriatic plate. Evolution of Dinaric Lake(s) from shallow freshwater aquatorium toward deep saline lake was influenced by northward movements of Adriatic Plate and the response of Pannonian Mass. The sediment column of Dinaride Neogene was devided into tree parts (Milojević, 1963). They lay, in places, above reddish (continental) Oligocene sediments with Helix (Čičić & Milojević, 1977), but mostly in the Sava trough (Ugljevik, Banovići). Otherwise above Mesozoic and Paleozoic rocks. First part: basal zone above lie several brown coal seams indicating that the Adriatic Plate push was divided into phases. Catastrophic earthquake pull down the forest together with its large dwellers (Chalicotherium grande, an of Ungulata with claws) and sorted tree trunks at southern side of the lake Plevlja (Krstić et al., 1994). In this period freshwater ostracodes, and numerous characean gyrogonites, among them a genus similar to the Oligocene Harissichara, fill up some of beds. None of Congeria pelecipods are present. Charophyta algae making yellowish-brown limestone in Middle Bosnian depression lie just bellow

  8. Diversity of freshwater Epsilonproteobacteria and dark inorganic carbon fixation in the sulphidic redoxcline of a meromictic karstic lake.

    PubMed

    Noguerola, Imma; Picazo, Antonio; Llirós, Marc; Camacho, Antonio; Borrego, Carles M

    2015-07-01

    Sulfidic redoxclines are a suitable niche for the growth and activity of different chemo- and photolithotrophic sulphide-oxidizing microbial groups such as the Epsilonproteobacteria and the green sulfur bacteria (GSB). We have investigated the diversity, abundance and contribution to inorganic carbon uptake of Epsilonproteobacteria in a meromictic basin of Lake Banyoles. CARD-FISH counts revealed that Epsilonproteobacteria were prevalent at the redoxcline in winter (maximum abundance of 2 × 10(6) cells mL(-1), ≈60% of total cells) but they were nearly absent in summer, when GSB bloomed. This seasonal trend was supported by 16S rRNA gene pyrotag datasets, which revealed that the epsilonproteobacterial community was mainly composed of a member of the genus Arcobacter. In situ incubations using NaH(14)CO3 and MAR-CARD-FISH observations showed that this population assimilated CO2 in the dark, likely being mainly responsible for the autotrophic activity at the redoxcline in winter. Clone libraries targeting the aclB gene provided additional evidence of the potential capacity of these epsilonproteobacteria to fix carbon via rTCA cycle. Our data reinforce the key role of Epsilonproteobacteria in linking carbon and sulphur cycles, extend their influence to freshwater karstic lakes and raise questions about the actual contribution of chemolithotrophy at their redoxcline and euxinic water compartments.

  9. Source and flux of POC in a karstic area in the Changjiang River watershed: impacts of reservoirs and extreme drought

    NASA Astrophysics Data System (ADS)

    Ji, Hongbing; Li, Cai; Ding, Huaijian; Gao, Yang

    2016-06-01

    Isotopes of carbon (C) and nitrogen (N) along with C / N ratios of particulate organic carbon (POC) were used to identify source and transformation of organic carbon in the suspended and surface sediments in a typical karstic watershed (the Wujiang River, an important tributary of the Changjiang River). Isotope data for suspended sediments indicate that POC was mainly derived from phytoplankton and C3-dominated soil with an increased contribution of phytoplankton in sites directly affected by the reservoir. In contrast, the POC in surface sediments was mainly derived from C3- and C4-dominated soil with little reservoir influence. The positive correlations of carbon and nitrogen isotopes between suspended and surface sediments indicated that these two carbon pools are tightly coupled. Our conservative estimation suggests that 1.17 × 1010 g of POC is transported to the Three Gorges Reservoir during the study period in 2013. POC yield in the Wujiang River (0.13 t km-2 yr-1) is much lower than those of large rivers with a high abundance of carbonate minerals. Based on the distribution pattern of POC yield, it is inferred that carbonate minerals (lithology) do not contribute significantly to the riverine POC. The cascade of reservoirs and extreme drought had a significant influence on the POC flux in the Wujiang River.

  10. Rainfall-runoff relationship of some catchments with karstic geomorphology under arid to semi-arid conditions

    NASA Astrophysics Data System (ADS)

    De Vera, Maximo R.

    1984-02-01

    The relationship between rainfall and runoff of fourteen catchments with a total area of 5983 km 2 in the northeastern zone of Libya was reviewed in an attempt to determine the effect of karstic geomorphology on the runoff coefficient. Available data since 1965 were collated and eight wadis with at least eleven flood events were used for linear regression analysis. The selected catchments are under arid to semi-arid conditions with mean annual rainfall of 50-500 mm and with surface geology consisting mostly of marly limestone which is favourable to karstification phenomena. The ratio of runoff to rainfall is extremely variable with a range of 0.0001-0.830, and therefore it is not a reliable criterion for runoff estimation, especially with the limited data subjected to statistical analysis. The regression analysis shows correlation coefficients from 0.219 to 0.89 with no apparent effect of size of catchment area. As indicated by the coefficient of determination, 4.8-80.3% of the variation in runoff has been accounted for by the regression. The extent and degree of karstification, if properly quantified, can be a significant factor for runoff prediction, in addition to rainfall intensity and duration, antecedent soil moisture, effective catchment area and other geomorphological features.

  11. Statistical analysis of aquifer-test results for nine regional aquifers in Louisiana

    USGS Publications Warehouse

    Martin, Angel; Early, D.A.

    1987-01-01

    This report, prepared as part of the Gulf Coast Regional Aquifer-System Analysis project, presents a compilation, summarization, and statistical analysis of aquifer-test results for nine regional aquifers in Louisiana. These are from youngest to oldest: The alluvial, Pleistocene, Evangeline, Jasper, Catahoula, Cockfield, Sparta, Carrizo, and Wilcox aquifers. Approximately 1,500 aquifer tests in U.S. Geological Survey files in Louisiana were examined and 1,001 were input to a computer file. Analysis of the aquifer test results and plots that describe aquifer hydraulic characteristics were made for each regional aquifer. Results indicate that, on the average, permeability (hydraulic conductivity) generally tends to decrease from the youngest aquifers to the oldest. The most permeable aquifers in Louisiana are the alluvial and Pleistocene aquifers; whereas, the least permeable are the Carrizo and Wilcox aquifers. (Author 's abstract)

  12. Aquifer thermal energy storage program

    NASA Technical Reports Server (NTRS)

    Fox, K.

    1980-01-01

    The purpose of the Aquifer Thermal Energy Storage Demonstration Program is to stimulate the interest of industry by demonstrating the feasibility of using a geological formation for seasonal thermal energy storage, thereby, reducing crude oil consumption, minimizing thermal pollution, and significantly reducing utility capital investments required to account for peak power requirements. This purpose will be served if several diverse projects can be operated which will demonstrate the technical, economic, environmental, and institutional feasibility of aquifer thermal energy storage systems.

  13. Employing hydrochemistry and stable isotopes in analyzing groundwater flow mechanism, dynamics in karst aquifer of the Lower Jordan Valley

    NASA Astrophysics Data System (ADS)

    Musallam, Shadha; Sauter, Martin; Marei, Amer

    2015-04-01

    Water is a valuable resource, especially in arid and semi arid areas. In order to do proper management of the water resources, studies on the aquifer system is essential. The study case is located in the lower part of the western Jordan Valley. This karstic area has different systems from which the upper and lower Mountain aquifer systems. Two representative springs were chosen for each aquifer, Sultan spring for the lower aquifer and Auja spring for the upper one. Sultan spring has a continues and constant discharge rate through the year while Auja spring has high oscillation in discharge accompanied by frequent dry-out in summer months and fast response to precipitation events. The two systems have been thought to be separated by an aquiclute, however after frequent intensive sampling of both springs during the raining winter season, This study shows that with the exception of Na+ and Cl- all other concentration of ions are very similar. The average of Sodium for Sultan spring is 33 mg/L, while the average Chloride for the same spring is 54.5 mg/L. As for Auja spring the average Sodium and Chloride are 24 mg/L and 39.4 mg/L respectively, therefore, the water of Sultan spring contains higher content of sodium and chloride than Auja, this could be related to the chemistry of the lower aquifer. The ratio of Na+/Cl- for Sultan and Auja springs are 0.92 and 0.94 respectively, this indicates that Auja is close to the rain ratio of 0.86 while Sultan (although slightly higher) may be closer to the Halite ratio of 1. The isotopic signature of 18O for both springs has shown to be very similar with only a -0.5‰ of difference in most cases, with a range of -5.2‰ to -6.2‰ for Sultan and -5.4‰ to -6.2‰ for Auja spring. These results may indicate the same recharge elevation for both springs in the Mountain area. On the other hand, in some places east to the major fault system, the shallow aquifer's 18O content in Jericho is close to that of Sultan spring, which could

  14. In Brief: Assessing carbonate aquifers

    NASA Astrophysics Data System (ADS)

    Showstack, Randy

    2009-07-01

    An assessment of water quality in 12 carbonate aquifers, mostly in the eastern and central United States, found that while water quality in the aquifers was highly variable, most of the samples met drinking water standards. The study, “Factors affecting water quality in selected carbonate aquifers in the United States, 1993-2005,” was released by the U.S. Geological Survey (USGS) on 26 June. According to the study, carbonate aquifers provide about 20% of the groundwater used as drinking water in the United States. The study, which included sample results for 151 chemical constituents or physical properties in 1042 wells and springs across 20 states, found that contaminants “were most often detected at concentrations less than human-health benchmarks except for nitrate.” The study also indicated that “the occurrence of anthropogenic contaminants was related to contaminant sources but also was affected by degree of aquifer confinement, ground-water age, and redox status. Areas with higher amounts of agricultural or urban land in unconfined aquifers were the most likely to have elevated concentrations of anthropogenic contaminants.”

  15. Diffuse-flow conceptualization and simulation of the Edwards Aquifer, San Antonio Region, Texas

    USGS Publications Warehouse

    Lindgren, R.J.

    2006-01-01

    A numerical ground-water-flow model (hereinafter, the conduit-flow Edwards aquifer model) of the karstic Edwards aquifer in south-central Texas was developed for a previous study on the basis of a conceptualization emphasizing conduit development and conduit flow, and included simulating conduits as one-cell-wide, continuously connected features. Uncertainties regarding the degree to which conduits pervade the Edwards aquifer and influence ground-water flow, as well as other uncertainties inherent in simulating conduits, raised the question of whether a model based on the conduit-flow conceptualization was the optimum model for the Edwards aquifer. Accordingly, a model with an alternative hydraulic conductivity distribution without conduits was developed in a study conducted during 2004-05 by the U.S. Geological Survey, in cooperation with the San Antonio Water System. The hydraulic conductivity distribution for the modified Edwards aquifer model (hereinafter, the diffuse-flow Edwards aquifer model), based primarily on a conceptualization in which flow in the aquifer predominantly is through a network of numerous small fractures and openings, includes 38 zones, with hydraulic conductivities ranging from 3 to 50,000 feet per day. Revision of model input data for the diffuse-flow Edwards aquifer model was limited to changes in the simulated hydraulic conductivity distribution. The root-mean-square error for 144 target wells for the calibrated steady-state simulation for the diffuse-flow Edwards aquifer model is 20.9 feet. This error represents about 3 percent of the total head difference across the model area. The simulated springflows for Comal and San Marcos Springs for the calibrated steady-state simulation were within 2.4 and 15 percent of the median springflows for the two springs, respectively. The transient calibration period for the diffuse-flow Edwards aquifer model was 1947-2000, with 648 monthly stress periods, the same as for the conduit-flow Edwards

  16. Interaction of alpha-L-aspartyl-D-phenylalanine methyl ester with the receptor site of the bitter taste.

    PubMed

    Lelj, F; Tancredi, T; Temussi, P A; Toniolo, C

    1980-12-01

    The analysis of the structure-activity relationship previously performed on the sweet L,L isomer of Asp-Phe-OMe was extended to the bitter L,D diastereoisomer. A combination of NMR measurements and of an original method of PEM calculations gives a description of the conformational state of the L,D isomer that can be effectively used to study the interaction with a previously proposed model of the bitter taste receptor site. PMID:7202705

  17. Interaction of alpha-L-aspartyl-D-phenylalanine methyl ester with the receptor site of the bitter taste.

    PubMed

    Lelj, F; Tancredi, T; Temussi, P A; Toniolo, C

    1980-12-01

    The analysis of the structure-activity relationship previously performed on the sweet L,L isomer of Asp-Phe-OMe was extended to the bitter L,D diastereoisomer. A combination of NMR measurements and of an original method of PEM calculations gives a description of the conformational state of the L,D isomer that can be effectively used to study the interaction with a previously proposed model of the bitter taste receptor site.

  18. Evaluation of groundwater residence time in a high mountain aquifer system (Sacramento Mountains, USA): insights gained from use of multiple environmental tracers

    NASA Astrophysics Data System (ADS)

    Land, Lewis; Timmons, Stacy

    2016-06-01

    The New Mexico Bureau of Geology and Mineral Resources (USA) has conducted a regional investigation of groundwater residence time within the southern Sacramento Mountains aquifer system using multiple environmental tracers. Results of the tracer surveys indicate that groundwater in the southern Sacramento Mountains ranges in age from less than 1 year to greater than 50 years, although the calculated ages contain uncertainties and vary significantly depending on which tracer is used. A distinctive feature of the results is discordance among the methods used to date groundwater in the study area. This apparent ambiguity results from the effects of a thick unsaturated zone, which produces non-conservative behavior among the dissolved gas tracers, and the heterogeneous character and semi-karstic nature of the aquifer system, which may yield water from matrix porosity, fractures, solution-enlarged conduits, or a combination of the three. The data also indicate mixing of groundwater from two or more sources, including recent recharge originating from precipitation at high elevations, old groundwater stored in the matrix, and pre-modern groundwater upwelling along fault zones. The tracer data have also been influenced by surface-water/groundwater exchange via losing streams and lower elevation springs (groundwater recycling). This study highlights the importance of using multiple tracers when conducting large-scale investigations of a heterogeneous aquifer system, and sheds light on characteristics of groundwater flow systems that can produce discrepancies in calculations of groundwater age.

  19. "A spoonful of sugar helps the medicine go down": bitter masking by sucrose among children and adults.

    PubMed

    Mennella, Julie A; Reed, Danielle R; Mathew, Phoebe S; Roberts, Kristi M; Mansfield, Corrine J

    2015-01-01

    Sweeteners are often added to liquid formulations of drugs but whether they merely make them better tasting or actually reduce the perception of bitterness remains unknown. In a group of children and adults, we determined whether adding sucrose to urea, caffeine, denatonium benzoate, propylthiouracil (PROP), and quinine would reduce their bitterness using a forced-choice method of paired comparisons. To better understand individual differences, adults also rated each solution using a more complex test (general Labeled Magnitude Scale [gLMS]) and were genotyped for the sweet taste receptor gene TAS1R3 and the bitter receptor TAS2R38. Sucrose suppressed the bitterness of each agent in children and adults. In adults, sucrose was effective in reducing the bitterness ratings from moderate to weak for all compounds tested, but those with the sensitive form of the sweet receptor reported greater reduction for caffeine and quinine. For PROP, sucrose was most effective for those who were genetically the most sensitive, although this did not attain statistical significance. Not only is the paired comparison method a valid tool to study how sucrose improves the taste of pediatric medicines among children but knowledge gleaned from basic research in bitter taste and how to alleviate it remains an important public health priority.

  20. Reinvestigation of the bitter compounds in carrots (Daucus carota L.) by using a molecular sensory science approach.

    PubMed

    Schmiech, Ludger; Uemura, Daisuke; Hofmann, Thomas

    2008-11-12

    In order to reinvestigate the key molecules inducing bitter off-taste of carrots ( Daucus carota L.), a sensory-guided fractionation approach was applied to bitter carrot extracts. Besides the previously reported bitter compounds, 6-methoxymellein (1), falcarindiol (2), falcarinol (3), and falcarindiol-3-acetate (4), the following compounds were identified for the first time as bitter compounds in carrots with low bitter recognition thresholds between 8 and 47 micromol/L: vaginatin (5), isovaginatin (6), 2-epilaserine oxide (7), laserine oxide (8), laserine (14), 2-epilaserine (15), 6,8-O-ditigloyl- (9), 6-O-angeloyl-, 8-O-tigloyl- (10), 6-O-tigloyl-, 8-O-angeloyl- (11), and 6-, 8-O-diangeloyl-6 ss,8alpha,11-trihydroxygermacra-1(10) E,4 E-diene (12), as well as 8-O-angeloyl-tovarol (13) and alpha-angeloyloxy-latifolone (16). Among these bitter molecules, compounds 9, 10, 13, and 16 were not previously identified in carrots and compounds 6, 11, and 12 were yet not reported in the literature.

  1. Discovery and genetic analysis of non-bitter Tartary buckwheat (Fagopyrum tataricum Gaertn.) with trace-rutinosidase activity

    PubMed Central

    Suzuki, Tatsuro; Morishita, Toshikazu; Mukasa, Yuji; Takigawa, Shigenobu; Yokota, Satoshi; Ishiguro, Koji; Noda, Takahiro

    2014-01-01

    In a screening of about 500 lines of Tartary buckwheat, we identified lines that contained no detectable rutinosidase isozymes using an in-gel detection assay. We confirmed that seeds of these individuals had only a trace level of in-vitro rutinosidase activity. To investigate the heritability of the trace-rutinosidase characteristic, we analyzed the progeny of crosses between rutinosidase trace-lines, ‘f3g-162’, and the ‘Hokkai T8’. The F2 progeny clearly divided into two groups: those with rutinosidase activity under 1.5 nkat/g seed (trace-rutinosidase) and those with activity over 400 nkat/g seed (normal rutinosidase). The segregation pattern of this trait in F2 progeny exhibited 1 : 3 ratio (trace-rutinosidase : normal rutinosidase), suggesting that the trace-rutinosidase trait is conferred by a single recessive gene; rutinosidase-trace A (rutA). In addition, sensory panelists evaluated the bitterness of flour from trace-rutinosidase individuals and did not detect bitterness, whereas flour from normal rutinosidase individuals was found to have strong bitterness. Although at least three bitter compounds have been reported in Tartary buckwheat seeds, our present findings indicate that rutin hydrolysis is the major contributing factor to bitterness. In addition, the trace-rutinosidase line identified here, ‘f3g-162’, is a promising material for generating a non-bitter Tartary buckwheat variety. PMID:25914588

  2. Discovery and genetic analysis of non-bitter Tartary buckwheat (Fagopyrum tataricum Gaertn.) with trace-rutinosidase activity.

    PubMed

    Suzuki, Tatsuro; Morishita, Toshikazu; Mukasa, Yuji; Takigawa, Shigenobu; Yokota, Satoshi; Ishiguro, Koji; Noda, Takahiro

    2014-12-01

    In a screening of about 500 lines of Tartary buckwheat, we identified lines that contained no detectable rutinosidase isozymes using an in-gel detection assay. We confirmed that seeds of these individuals had only a trace level of in-vitro rutinosidase activity. To investigate the heritability of the trace-rutinosidase characteristic, we analyzed the progeny of crosses between rutinosidase trace-lines, 'f3g-162', and the 'Hokkai T8'. The F2 progeny clearly divided into two groups: those with rutinosidase activity under 1.5 nkat/g seed (trace-rutinosidase) and those with activity over 400 nkat/g seed (normal rutinosidase). The segregation pattern of this trait in F2 progeny exhibited 1 : 3 ratio (trace-rutinosidase : normal rutinosidase), suggesting that the trace-rutinosidase trait is conferred by a single recessive gene; rutinosidase-trace A (rutA). In addition, sensory panelists evaluated the bitterness of flour from trace-rutinosidase individuals and did not detect bitterness, whereas flour from normal rutinosidase individuals was found to have strong bitterness. Although at least three bitter compounds have been reported in Tartary buckwheat seeds, our present findings indicate that rutin hydrolysis is the major contributing factor to bitterness. In addition, the trace-rutinosidase line identified here, 'f3g-162', is a promising material for generating a non-bitter Tartary buckwheat variety.

  3. “A Spoonful of Sugar Helps the Medicine Go Down”: Bitter Masking by Sucrose Among Children and Adults

    PubMed Central

    Reed, Danielle R.; Mathew, Phoebe S.; Roberts, Kristi M.; Mansfield, Corrine J.

    2015-01-01

    Sweeteners are often added to liquid formulations of drugs but whether they merely make them better tasting or actually reduce the perception of bitterness remains unknown. In a group of children and adults, we determined whether adding sucrose to urea, caffeine, denatonium benzoate, propylthiouracil (PROP), and quinine would reduce their bitterness using a forced-choice method of paired comparisons. To better understand individual differences, adults also rated each solution using a more complex test (general Labeled Magnitude Scale [gLMS]) and were genotyped for the sweet taste receptor gene TAS1R3 and the bitter receptor TAS2R38. Sucrose suppressed the bitterness of each agent in children and adults. In adults, sucrose was effective in reducing the bitterness ratings from moderate to weak for all compounds tested, but those with the sensitive form of the sweet receptor reported greater reduction for caffeine and quinine. For PROP, sucrose was most effective for those who were genetically the most sensitive, although this did not attain statistical significance. Not only is the paired comparison method a valid tool to study how sucrose improves the taste of pediatric medicines among children but knowledge gleaned from basic research in bitter taste and how to alleviate it remains an important public health priority. PMID:25381313

  4. The Role of Bitter and Sweet Taste Receptors in Upper Airway Immunity.

    PubMed

    Workman, Alan D; Palmer, James N; Adappa, Nithin D; Cohen, Noam A

    2015-12-01

    Over the past several years, taste receptors have emerged as key players in the regulation of innate immune defenses in the mammalian respiratory tract. Several cell types in the airway, including ciliated epithelial cells, solitary chemosensory cells, and bronchial smooth muscle cells, all display chemoresponsive properties that utilize taste receptors. A variety of bitter products secreted by microbes are detected with resultant downstream inflammation, increased mucous clearance, antimicrobial peptide secretion, and direct bacterial killing. Genetic variation of bitter taste receptors also appears to play a role in the susceptibility to infection in respiratory disease states, including that of chronic rhinosinusitis. Ongoing taste receptor research may yield new therapeutics that harness innate immune defenses in the respiratory tract and may offer alternatives to antibiotic treatment. The present review discusses taste receptor-protective responses and analyzes the role these receptors play in mediating airway immune function.

  5. Mozambioside Is an Arabica-Specific Bitter-Tasting Furokaurane Glucoside in Coffee Beans.

    PubMed

    Lang, Roman; Klade, Stefan; Beusch, Anja; Dunkel, Andreas; Hofmann, Thomas

    2015-12-01

    Sensory-guided fractionation of a roasted coffee beverage revealed a highly polar, bitter-tasting subfraction, from which the furokaurane glucoside mozambioside was isolated and identified in its chemical structure by means of HDMS and NMR spectra. Sensory evaluation revealed a bitter taste recognition threshold of 60 (± 10) μmol/L. UPLC-HDMS quantitation of raw coffee beans showed that Arabica coffees contained 396-1188 nmol/g mozambioside, whereas only traces (<5 nmol/g) were detected in Robusta coffees, thus suggesting that mozambioside can be used as an analytical marker for Arabica coffee. Roasted Arabica contained a substantially reduced concentration (232 ± 37 nmol/g), indicating partial degradation of mozambioside during coffee roasting. Mozambioside was nearly quantitatively extracted into the aqueous brew during coffee-making (86-98%).

  6. Diet Shapes the Evolution of the Vertebrate Bitter Taste Receptor Gene Repertoire

    PubMed Central

    Li, Diyan; Zhang, Jianzhi

    2014-01-01

    Vertebrate Tas2r taste receptors bind to bitter compounds, which are typically poisonous, to elicit bitter sensation to prevent the ingestion of toxins. Previous studies noted a marked variation in the number of Tas2r genes among species, but the underlying cause is unclear. To address this question, we compile the Tas2r gene repertoires from 41 mammals, 4 birds, 2 reptiles, 1 amphibian, and 6 fishes. The number of intact Tas2r genes varies from 0 in the bottlenose dolphin to 51 in the Western clawed frog, with numerous expansions and contractions of the gene family throughout vertebrates, especially among tetrapods. The Tas2r gene number in a species correlates with the fraction of plants in its diet. Because plant tissues contain more toxic compounds than animal tissues do, our observation supports the hypothesis that dietary toxins are a major selective force shaping the diversity of the Tas2r repertoire. PMID:24202612

  7. Mozambioside Is an Arabica-Specific Bitter-Tasting Furokaurane Glucoside in Coffee Beans.

    PubMed

    Lang, Roman; Klade, Stefan; Beusch, Anja; Dunkel, Andreas; Hofmann, Thomas

    2015-12-01

    Sensory-guided fractionation of a roasted coffee beverage revealed a highly polar, bitter-tasting subfraction, from which the furokaurane glucoside mozambioside was isolated and identified in its chemical structure by means of HDMS and NMR spectra. Sensory evaluation revealed a bitter taste recognition threshold of 60 (± 10) μmol/L. UPLC-HDMS quantitation of raw coffee beans showed that Arabica coffees contained 396-1188 nmol/g mozambioside, whereas only traces (<5 nmol/g) were detected in Robusta coffees, thus suggesting that mozambioside can be used as an analytical marker for Arabica coffee. Roasted Arabica contained a substantially reduced concentration (232 ± 37 nmol/g), indicating partial degradation of mozambioside during coffee roasting. Mozambioside was nearly quantitatively extracted into the aqueous brew during coffee-making (86-98%). PMID:26585544

  8. Reduction of oil bitterness by heating of olive (Olea europaea) fruits.

    PubMed

    García, J M; Yousfi, K; Mateos, R; Olmo, M; Cert, A

    2001-09-01

    Olives (Olea europaea) of the Manzanilla and Verdial varieties, harvested at the green mature stage of ripening, were heated at 30, 40, 45, and 50 degrees C during 24 h and at 40 degrees C during 24, 48, and 72 h, respectively. Just after treatments, oils were physically extracted from the olives. Olive heating promotes a reduction of oil bitterness in direct relationship to the time and temperature used. Fruit heating at < or =40 degrees C during 24 h did not produce significant changes of acidity, UV absorption, peroxide index, panel test score, or oxidative stability of the obtained oils. Both longer treatments at 40 degrees C and heating at >40 degrees C yielded oils with less oxidative stability. Oils obtained from olives heated at > or =40 degrees C showed higher concentrations of chlorophylls and carotenes. For each olive variety, a good correlation between oil bitterness and content of hydroxytyrosol secoiridoid derivatives was found. PMID:11559116

  9. The Role of Bitter and Sweet Taste Receptors in Upper Airway Immunity.

    PubMed

    Workman, Alan D; Palmer, James N; Adappa, Nithin D; Cohen, Noam A

    2015-12-01

    Over the past several years, taste receptors have emerged as key players in the regulation of innate immune defenses in the mammalian respiratory tract. Several cell types in the airway, including ciliated epithelial cells, solitary chemosensory cells, and bronchial smooth muscle cells, all display chemoresponsive properties that utilize taste receptors. A variety of bitter products secreted by microbes are detected with resultant downstream inflammation, increased mucous clearance, antimicrobial peptide secretion, and direct bacterial killing. Genetic variation of bitter taste receptors also appears to play a role in the susceptibility to infection in respiratory disease states, including that of chronic rhinosinusitis. Ongoing taste receptor research may yield new therapeutics that harness innate immune defenses in the respiratory tract and may offer alternatives to antibiotic treatment. The present review discusses taste receptor-protective responses and analyzes the role these receptors play in mediating airway immune function. PMID:26492878

  10. Beneficial Role of Bitter Melon Supplementation in Obesity and Related Complications in Metabolic Syndrome

    PubMed Central

    Subhan, Nusrat; Rahman, Md Mahbubur; Jain, Preeti; Reza, Hasan Mahmud

    2015-01-01

    Diabetes, obesity, and metabolic syndrome are becoming epidemic both in developed and developing countries in recent years. Complementary and alternative medicines have been used since ancient era for the treatment of diabetes and cardiovascular diseases. Bitter melon is widely used as vegetables in daily food in Bangladesh and several other countries in Asia. The fruits extract of bitter melon showed strong antioxidant and hypoglycemic activities in experimental condition both in vivo and in vitro. Recent scientific evaluation of this plant extracts also showed potential therapeutic benefit in diabetes and obesity related metabolic dysfunction in experimental animals and clinical studies. These beneficial effects are mediated probably by inducing lipid and fat metabolizing gene expression and increasing the function of AMPK and PPARs, and so forth. This review will thus focus on the recent findings on beneficial effect of Momordica charantia extracts on metabolic syndrome and discuss its potential mechanism of actions. PMID:25650336

  11. Structural control on the evolution of groundwater quality for B2A7 aquifer in the area extending from Ajlun to Yarmouk river in Jordan

    NASA Astrophysics Data System (ADS)

    Raggad, Marwan; Salameh, Elias; Magri, Fabien; Muller, Peter; Siebert, Christian

    2015-04-01

    Groundwater flow in the Northwestern highlands of Jordan is controlled y the Ajlun Heights were groundwater flows towards north and west along the Yarmouk river and the Jordan Valley. Due to water rock interactions, groundwater that discharges in the Jordan Valley and along the Yarmuk River is thermal, radioactive and mineralized. Its total dissolved solids especially in the confined parts of the aquifer. Electrical conductivity of groundwater in the unconfined aquifer of B2A7 ranges between 500 to 700 µs/cm and increases up to 1600 µs/cm towards the confined part of the aquifer with a notable increase in Na and Cl towards the discharge areas. According to the chloride content in the groundwater the evaporation in the recharge areas is considered to be high representing 82% of the total rainfall. Groundwaters are classified as calcium bicarbonate types with Mg/Ca ratios varying from 0.11 to1.21 and Na/Cl ratio in the range of 0.49 to 1.85. The chemical evolution of groundwater from Ajlun Heights toward Jordan Valley and Yarmouk River is marked by a progressive decrease in calcium and bicarbonate with increase of sodium, and chloride due to halite dissolution and upward percolation of deep saline groundwater. The 3D modeling for the aquifer system indicated the rule of geologic structure in the groundwater digenesis through upward and downward leakage enhanced along high permeability lineaments. According to the modeled water budget, the inflow to the upper B2A7 Aquifer 54 *106 m3/yr replenishing the B2A7 system as underground flow in the karstic limestone of the vadose zone. The underground discharge to the Yarmouk River and Jordan valley modeled to be 23.2 *106 m3/yr as underflow to the springs. The leakage from B2A7 aquifer into the lower aquifer is about 9.7 *106 m3/yr. Within the north western lowered elevations the hydraulic different between upper and deep aquifers is at minimum an upward leakage and seems to take place through the main faults trending EW

  12. Partially purified bitter gourd (Momordica charantia) peroxidase catalyzed decolorization of textile and other industrially important dyes.

    PubMed

    Akhtar, Suhail; Ali Khan, Amjad; Husain, Qayyum

    2005-11-01

    The aim of this study was to evaluate the enzymatic action of partially purified bitter gourd peroxidase for the degradation/decolorization of complex aromatic structures. Twenty-one dyes, with a wide spectrum of chemical groups, currently being used by the textile and other important industries have been selected for the study. Here, for the first time we have shown peroxidases from Momordica charantia (300 EU/gm of vegetable) to be highly effective in decolorizing industrially important dyes. Dye solutions, containing 50-200 mg dye/l, were used for the treatment with bitter gourd peroxidase (specific activity of 99.0 EU/mg protein). M. charantia peroxidases were able to decolorize most of the textile dyes by forming insoluble precipitate. When the textile dyes were treated with increasing concentration of enzyme, it was observed that greater fraction of the color was removed but four out of eight reactive dyes were recalcitrant to decolorization by bitter gourd peroxidase. Step-wise addition of enzyme to the decolorizing reaction mixture at the interval of 1h further enhanced the dye decolorization. The rate of decolorization was enhanced when the dyes were incubated with fixed quantity of enzyme for increasing times. Decolorization of non-textile dyes resulted in the degradation and removal of dyes from the solution without any precipitate formation. Decolorization rate was drastically increased when the textile and other industrially important non-textile dyes were treated with bitter gourd peroxidase in presence of 1.0 mM 1-hydroxybenzotriazole. Complex mixtures of dyes were prepared by taking three to four reactive textile and non-textile dyes in equal proportions. Each mixture was decolorized by more than 80% when treated with the enzyme in presence of 1.0 mM 1-hydroxybenzotriazole. Our data suggest that the peroxidase/mediator system is an effective biocatalyst for the treatment of effluents containing recalcitrant dyes from textile, dye manufacturing

  13. Hop bitter acids exhibit anti-fibrogenic effects on hepatic stellate cells in vitro.

    PubMed

    Saugspier, Michael; Dorn, Christoph; Thasler, Wolfgang E; Gehrig, Manfred; Heilmann, Jörg; Hellerbrand, Claus

    2012-04-01

    Female inflorescences of the hop plant Humulus lupulus L. contain a variety of secondary metabolites with bitter acids (BA) as quantitatively dominating secondary metabolites. The use of hops in beer brewing has a long history due to the antibacterial effects of the BA and their typical bitter taste. Furthermore, hop cones are used in traditional medicine and for pharmaceutical purposes. Recent studies indicate that BA may affect activity of the transcription factor NFκB. NFκB plays a key role in the activation process of hepatic stellate cells (HSC), which is the key event of hepatic fibrosis. The aim of this study was to investigate the effect of BA on HSC (activation) and their potential to inhibit molecular processes involved in the pathogenesis of hepatic fibrosis. HSC were isolated from murine and human liver tissue and incubated with a characterized fraction of bitter acids purified from a CO(2) hop extract. At a concentration of 25μg/ml BA started to induce LDH leakage. Already at lower concentrations BA lead to a dose dependent inhibition of HSC proliferation and inhibited IκB-α-phosphorylation, nuclear p65 translocation and binding activity in a dose dependent way (up to 10μg/ml). Accordingly, the same BA-doses inhibited the expression of pro-inflammatory and NFκB regulated genes as MCP-1 and RANTES, but did not affect expression of genes not related to NFκB signaling. In addition to the effect on activated HSC, BA inhibited the in vitro activation process of freshly isolated HSC as evidenced by delayed expression of collagen I and α-SMA mRNA and protein. Together, these findings indicate that BA inhibit NFκB activation, and herewith the activation and development of profibrogenic phenotype of HSC. Thus, bitter acids appear as potential functional nutrients for the prevention or treatment hepatic fibrosis in chronic liver disease.

  14. Genetic diversity of bitter taste receptor gene family in Sichuan domestic and Tibetan chicken populations.

    PubMed

    Su, Yuan; Li, Diyan; Gaur, Uma; Wang, Yan; Wu, Nan; Chen, Binlong; Xu, Zhongxian; Yin, Huadong; Hu, Yaodong; Zhu, Qing

    2016-09-01

    The sense of bitter taste plays a critical role in animals as it can help them to avoid intake of toxic and harmful substances. Previous research had revealed that chicken has only three bitter taste receptor genes (Tas2r1, Tas2r2 and Tas2r7). To better understand the genetic polymorphisms and importance of bitter taste receptor genes (Tas2rs) in chicken, here, we sequenced Tas2rs of 30 Sichuan domestic chickens and 30 Tibetan chickens. Thirteen single-nucleotide polymorphisms (SNPs) including three nonsynonymous mutations (m.359G>C, m.503C>A and m.583A>G) were detected in Tas2r1 (m. is the abbreviation for mutation); three SNPs were detected in Tas2r2, but none of them were missense mutation; eight SNPs were detected in Tas2r7 including six nonsynonymous substitutions (m.178G>A, m.421A>C, m.787C>T, m.832G>T, m.907A>T and m.943G>A). Tajima's D neutral test indicates that there is no population expansion in both populations, and the size of the population is relatively stable. All the three networks indicate that red jungle fowls share haplotypes with domestic chickens. In addition, we found that haplotypes H1 and HE1 were positively associated with high-altitude adaptation, whereas haplotypes H4 and HE4 showed a negative correlation with high-altitude adaptation in Tas2rs. Although, chicken has only three Tas2rs, our results showed that both Sichuan domestic chickens and Tibetan chickens have abundant haplotypes in Tas2rs, especially in Tas2r7, which might help chickens to recognize a wide variety of bitter-tasting compounds. PMID:27659339

  15. Sweetness and bitterness taste of meals per se does not mediate gastric emptying in humans.

    PubMed

    Little, Tanya J; Gupta, Nili; Case, R Maynard; Thompson, David G; McLaughlin, John T

    2009-09-01

    In cell line and animal models, sweet and bitter tastants induce secretion of signaling peptides (e.g., glucagon-like peptide-1 and cholecystokinin) and slow gastric emptying (GE). Whether human GE and appetite responses are regulated by the sweetness or bitterness per se of ingested food is, however, unknown. We aimed to determine whether intragastric infusion of "equisweet" (Study A) or "equibitter" (Study B) solutions slow GE to the same extent, and whether a glucose solution made sweeter by the addition of saccharin will slow GE more potently than glucose alone. Healthy nonobese subjects were studied in a single-blind, randomized fashion. Subjects received 500-ml intragastric infusions of predetermined equisweet solutions of glucose (560 mosmol/kgH(2)O), fructose (290 mosmol/kgH(2)O), aspartame (200 mg), and saccharin (50 mg); twice as sweet glucose + saccharin, water (volumetric control) (Study A); or equibitter solutions of quinine (0.198 mM), naringin (1 mM), or water (Study B). GE was evaluated using a [(13)C]acetate breath test, and hunger and fullness were scored using visual analog scales. In Study A, equisweet solutions did not empty similarly. Fructose, aspartame, and saccharin did not slow GE compared with water, but glucose did (P < 0.05). There was no additional effect of the sweeter glucose + saccharin solution (P > 0.05, compared with glucose alone). In Study B, neither bitter tastant slowed GE compared with water. None of the solutions modulated perceptions of hunger or fullness. We conclude that, in humans, the presence of sweetness and bitterness taste per se in ingested solutions does not appear to signal to influence GE or appetite perceptions.

  16. Sequence Analysis of Bitter Taste Receptor Gene Repertoires in Different Ruminant Species

    PubMed Central

    Monteiro Ferreira, Ana; Tomás Marques, Andreia; Bhide, Mangesh; Cubric-Curik, Vlatka; Hollung, Kristin; Knight, Christopher Harold; Raundrup, Katrine; Lippolis, John; Palmer, Mitchell; Sales-Baptista, Elvira; Araújo, Susana Sousa; de Almeida, André Martinho

    2015-01-01

    Bitter taste has been extensively studied in mammalian species and is associated with sensitivity to toxins and with food choices that avoid dangerous substances in the diet. At the molecular level, bitter compounds are sensed by bitter taste receptor proteins (T2R) present at the surface of taste receptor cells in the gustatory papillae. Our work aims at exploring the phylogenetic relationships of T2R gene sequences within different ruminant species. To accomplish this goal, we gathered a collection of ruminant species with different feeding behaviors and for which no genome data is available: American bison, chamois, elk, European bison, fallow deer, goat, moose, mouflon, muskox, red deer, reindeer and white tailed deer. The herbivores chosen for this study belong to different taxonomic families and habitats, and hence, exhibit distinct foraging behaviors and diet preferences. We describe the first partial repertoires of T2R gene sequences for these species obtained by direct sequencing. We then consider the homology and evolutionary history of these receptors within this ruminant group, and whether it relates to feeding type classification, using MEGA software. Our results suggest that phylogenetic proximity of T2R genes corresponds more to the traditional taxonomic groups of the species rather than reflecting a categorization by feeding strategy. PMID:26061084

  17. Sequence Analysis of Bitter Taste Receptor Gene Repertoires in Different Ruminant Species.

    PubMed

    Monteiro Ferreira, Ana; Tomás Marques, Andreia; Bhide, Mangesh; Cubric-Curik, Vlatka; Hollung, Kristin; Knight, Christopher Harold; Raundrup, Katrine; Lippolis, John; Palmer, Mitchell; Sales-Baptista, Elvira; Araújo, Susana Sousa; de Almeida, André Martinho

    2015-01-01

    Bitter taste has been extensively studied in mammalian species and is associated with sensitivity to toxins and with food choices that avoid dangerous substances in the diet. At the molecular level, bitter compounds are sensed by bitter taste receptor proteins (T2R) present at the surface of taste receptor cells in the gustatory papillae. Our work aims at exploring the phylogenetic relationships of T2R gene sequences within different ruminant species. To accomplish this goal, we gathered a collection of ruminant species with different feeding behaviors and for which no genome data is available: American bison, chamois, elk, European bison, fallow deer, goat, moose, mouflon, muskox, red deer, reindeer and white tailed deer. The herbivores chosen for this study belong to different taxonomic families and habitats, and hence, exhibit distinct foraging behaviors and diet preferences. We describe the first partial repertoires of T2R gene sequences for these species obtained by direct sequencing. We then consider the homology and evolutionary history of these receptors within this ruminant group, and whether it relates to feeding type classification, using MEGA software. Our results suggest that phylogenetic proximity of T2R genes corresponds more to the traditional taxonomic groups of the species rather than reflecting a categorization by feeding strategy.

  18. Expression of bitter taste receptor Tas2r105 in mouse kidney.

    PubMed

    Liu, Xin; Gu, Fu; Jiang, Li; Chen, Fuxue; Li, Feng

    2015-03-20

    The kidney is the most important excretory organ in the body and plays an essential role in maintaining homeostasis in vivo by conserving body fluid and electrolytes and removing metabolic waste. In this study, three types of transgenic system were used to investigate the expression of the bitter taste receptor Tas2r105 in mouse renal tissue (Tas2r105-GFP/Cre, Tas2r105-GFP/Cre-DTA and Tas2r105-GFP/Cre-LacZ). The results suggest that bitter taste receptors Tas2r105 and Tas2r106 are expressed in the renal corpuscle and the renal tubule, including the proximal tubule and distal tubule. Expression of α-gustducin, an important component of taste signal transduction, was also detected in mouse kidney. Meanwhile, conditional diphtheria toxin (DTA) expression in Tas2r105+ cells caused an increase in size of the glomerulus and renal tubule, accompanied by a decrease in cell density in the glomerulus. This indicates that Tas2r105+ cells play an important role in maintaining the structure of the glomerulus and renal tubules. Overall, the current study collectively demonstrates that cells labeled by bitter taste receptor expression may play a critical role in controlling human health, and have properties far beyond the original concept of taste perception.

  19. Time-intensity profile of pitanga nectar (Eugenia uniflora L.) with different sweeteners: Sweetness and bitterness.

    PubMed

    Freitas, Mírian Luisa Faria; de Lima Dutra, Mariana Borges; Bolini, Helena Maria André

    2016-01-01

    Pitanga has been used by the Brazilian food industry mainly for juice production. This fruit shows good economic potential due to its high concentration of vitamins and minerals. The aim of the present work was to characterize the time-intensity profile of pitanga nectar sweetened with different sweeteners to verify differences on the perception of sweet and bitter tastes. The sweeteners used to replace sucrose were sucralose, aspartame, stevia 40% rebaudioside A, stevia 95% rebaudioside A, neotame, and 2:1 cyclamate/saccharin blend. Fifteen assessors were selected according to their discriminating capability and trained to participate in the time-intensity analysis for sweetness and bitterness. The samples prepared with sucralose and 2:1 cyclamate/saccharin blend presented a similar sweetness profile to the sample prepared with sucrose, and the samples prepared with sucralose and aspartame presented a similar bitterness profile to the sample prepared with sucrose. Thus, sucralose would be the most suitable sweetener to replace sucrose in pitanga nectar. PMID:25627677

  20. Formulation development and evaluation of metformin chewing gum with bitter taste masking

    PubMed Central

    Mostafavi, Sayed Abolfazl; Varshosaz, Jaleh; Arabian, Saber

    2014-01-01

    Background: Medicated gums are intended to be chewed and act either locally, absorbed via the buccal mucosa or swallowed with saliva. We prepared the metformin gum to overcome its side effects including vomiting, diarrhea, and abdomen discomfort. Furthermore, it could be useful for those who have swallowing problems. Materials and Methods: Metformin hydrochloride (250 mg) with suitable sweeteners was mixed manually for 5 min. This mixture was spray dried, freeze dried, or directly mixed with chewing gum base. Glycerin, xylitol, and menthol were added and the produced paste was kept in the freezer for 2 h to be stable. As the metformin shows bitter taste, we tried to mask this unpleasant taste with using different methods explained. The releasing pattern was evaluated by using a mechanical chewing machine. The best formulation with the optimized releasing pattern, suitable physicochemical properties and pleasant taste were selected. Content uniformity, releasing percent, and other physicochemical properties were identified as well. Taste, flavor, and appearance characteristics were evaluated by using a self-made questionnaire based on the hedonic test method. Results: The chewing gum dosage content was about 86.2%. The release rate of metformin chewing gum was about 70% after 5 min of mastication. Masking the bitter taste of drug was achieved by using acesulfame-isomalt as sweeteners and prepared it by freeze drying equipment. Conclusion: Metfornin chewing gum had suitable appearance and appropriate invitro characteristics that fallow the pharmacopeia suggestions. This chewable gum showed bitterness suppression with a suitable release rate. PMID:24800181

  1. Perinatal administration of a bitter tastant influences gene expression in chicken palate and duodenum.

    PubMed

    Cheled-Shoval, Shira L; Behrens, Maik; Meyerhof, Wolfgang; Niv, Masha Y; Uni, Zehava

    2014-12-31

    Bitter taste receptors (Tas2rs) and downstream effectors are responsible for mediating bitterness perception and regulation of food choice in mammals. Using RT-PCR, we demonstrated the expression of three Tas2rs and taste signal transduction molecules, α-gustducin, PLCβ2, and TRPM5, in the palate, tongue, and gastrointestinal tract sections in chicken. The bitter tastant quinine activates all three chicken Tas2rs in vitro as shown using calcium-imaging assays of transfected cells. Administration of quinine postnatally or perinatally (both pre- and posthatch) to chickens increased the expression of Tas2r genes in the palate by 6.45-fold (ggTas2r1 postnatal treatment), 4.86-fold (ggTas2r1 perinatal treatment), and 4.48-fold (ggTas2r7 postnatal treatment) compared to the genes' expression in the naı̈ve group respectively, and affected taste related gene expression in the duodenum. Whereas no-choice intake of quinine solution was not significantly lower than that of water in naı̈ve chicks, the treatment groups postnatal, prenatal, and perinatal showed significantly lower intake of quinine by 56.1, 47.7, and 50.2%, respectively, suggesting a possible trend toward sensitization. These results open new venues toward unraveling the formative stages shaping food intake and nutrition in chicken.

  2. Birds Generally Carry a Small Repertoire of Bitter Taste Receptor Genes

    PubMed Central

    Wang, Kai; Zhao, Huabin

    2015-01-01

    As they belong to the most species-rich class of tetrapod vertebrates, birds have long been believed to possess an inferior taste system. However, the bitter taste is fundamental in birds to recognize dietary toxins (which are typically bitter) in potential food sources. To characterize the evolution of avian bitter taste receptor genes (Tas2rs) and to test whether dietary toxins have shaped the repertoire size of avian Tas2rs, we examined 48 genomes representing all but 3 avian orders. The total number of Tas2r genes was found to range from 1 in the domestic pigeon to 12 in the bar-tailed trogon, with an average of 4, which suggested that a much smaller Tas2r gene repertoire exists in birds than in other vertebrates. Furthermore, we uncovered a positive correlation between the number of putatively functional Tas2rs and the abundance of potential toxins in avian diets. Because plant products contain more toxins than animal tissues and insects release poisonous defensive secretions, we hypothesized that herbivorous and insectivorous birds may demand more functional Tas2rs than carnivorous birds feeding on noninsect animals. Our analyses appear to support this hypothesis and highlight the critical role of taste perception in birds. PMID:26342138

  3. Lineage-Specific Loss of Function of Bitter Taste Receptor Genes in Humans and Nonhuman Primates

    PubMed Central

    Go, Yasuhiro; Satta, Yoko; Takenaka, Osamu; Takahata, Naoyuki

    2005-01-01

    Since the process of becoming dead genes or pseudogenes (pseudogenization) is irreversible and can occur rather rapidly under certain environmental circumstances, it is one plausible determinant for characterizing species specificity. To test this evolutionary hypothesis, we analyzed the tempo and mode of duplication and pseudogenization of bitter taste receptor (T2R) genes in humans as well as in 12 nonhuman primates. The results show that primates have accumulated more pseudogenes than mice after their separation from the common ancestor and that lineage-specific pseudogenization becomes more conspicuous in humans than in nonhuman primates. Although positive selection has operated on some amino acids in extracellular domains, functional constraints against T2R genes are more relaxed in primates than in mice and this trend has culminated in the rapid deterioration of the bitter-tasting capability in humans. Since T2R molecules play an important role in avoiding generally bitter toxic and harmful substances, substantial modification of the T2R gene repertoire is likely to reflect different responses to changes in the environment and to result from species-specific food preference during primate evolution. PMID:15744053

  4. Birds Generally Carry a Small Repertoire of Bitter Taste Receptor Genes.

    PubMed

    Wang, Kai; Zhao, Huabin

    2015-09-04

    As they belong to the most species-rich class of tetrapod vertebrates, birds have long been believed to possess an inferior taste system. However, the bitter taste is fundamental in birds to recognize dietary toxins (which are typically bitter) in potential food sources. To characterize the evolution of avian bitter taste receptor genes (Tas2rs) and to test whether dietary toxins have shaped the repertoire size of avian Tas2rs, we examined 48 genomes representing all but 3 avian orders. The total number of Tas2r genes was found to range from 1 in the domestic pigeon to 12 in the bar-tailed trogon, with an average of 4, which suggested that a much smaller Tas2r gene repertoire exists in birds than in other vertebrates. Furthermore, we uncovered a positive correlation between the number of putatively functional Tas2rs and the abundance of potential toxins in avian diets. Because plant products contain more toxins than animal tissues and insects release poisonous defensive secretions, we hypothesized that herbivorous and insectivorous birds may demand more functional Tas2rs than carnivorous birds feeding on noninsect animals. Our analyses appear to support this hypothesis and highlight the critical role of taste perception in birds.

  5. Structural and Sensory Characterization of Bitter Tasting Steroidal Saponins from Asparagus Spears (Asparagus officinalis L.).

    PubMed

    Dawid, Corinna; Hofmann, Thomas

    2012-12-01

    Application of sequential solvent extraction and iterative chromatographic separation in combination with taste dilution analysis recently revealed a series of steroidal saponins as the key contributors to the typical bitter taste of white asparagus spears (Asparagus officinalis L.). Besides six previously reported saponins, (25R)-furost-5-en-3β,22,26-triol-3-O-[α-L-rhamnopyranosyl-(1→4)-β-D-glucopyranoside]-26-O-β-D-glucopyranoside, (25R)-furostane-3β,22,26-triol-3-O-[α-L-rhamnopyranosyl-(1→4)-β-D-glucopyranoside]-26-O-β-D-glucopyranoside, and (25S)-furostane-3β,22,26-triol-3-O-[α-L-rhamnopyranosyl-(1→4)-β-D-glucopyranoside]-26-O-β-D-glucopyranoside, and 3-O-[{α-L-rhamnopyranosyl-(1→2)}{α-L-rhamnopyranosyl-(1→4)}-β-D-glucopyranosyl]-(25S)-spirost-5-ene-3β-ol were identified for the first time as key bitter compounds in the edible spears of white asparagus by means of LC-MS/MS, LC-TOF-MS, 1D/2D-NMR spectroscopy, and hydrolysis experiments. This paper presents the isolation, structure determination, and sensory activity of these saponins. Depending on their chemical structure, the saponins identified showed human bitter recognition thresholds between 10.9 and 199.7 μmol/L (water).

  6. Time-intensity profile of pitanga nectar (Eugenia uniflora L.) with different sweeteners: Sweetness and bitterness.

    PubMed

    Freitas, Mírian Luisa Faria; de Lima Dutra, Mariana Borges; Bolini, Helena Maria André

    2016-01-01

    Pitanga has been used by the Brazilian food industry mainly for juice production. This fruit shows good economic potential due to its high concentration of vitamins and minerals. The aim of the present work was to characterize the time-intensity profile of pitanga nectar sweetened with different sweeteners to verify differences on the perception of sweet and bitter tastes. The sweeteners used to replace sucrose were sucralose, aspartame, stevia 40% rebaudioside A, stevia 95% rebaudioside A, neotame, and 2:1 cyclamate/saccharin blend. Fifteen assessors were selected according to their discriminating capability and trained to participate in the time-intensity analysis for sweetness and bitterness. The samples prepared with sucralose and 2:1 cyclamate/saccharin blend presented a similar sweetness profile to the sample prepared with sucrose, and the samples prepared with sucralose and aspartame presented a similar bitterness profile to the sample prepared with sucrose. Thus, sucralose would be the most suitable sweetener to replace sucrose in pitanga nectar.

  7. Targeting extra-oral bitter taste receptors modulates gastrointestinal motility with effects on satiation

    PubMed Central

    Avau, Bert; Rotondo, Alessandra; Thijs, Theo; Andrews, Christopher N.; Janssen, Pieter; Tack, Jan; Depoortere, Inge

    2015-01-01

    Bitter taste receptors (TAS2Rs) are present in extra-oral tissues, including gut endocrine cells. This study explored the presence and mechanism of action of TAS2R agonists on gut smooth muscle in vitro and investigated functional effects of intra-gastric administration of TAS2R agonists on gastric motility and satiation. TAS2Rs and taste signalling elements were expressed in smooth muscle tissue along the mouse gut and in human gastric smooth muscle cells (hGSMC). Bitter tastants induced concentration and region-dependent contractility changes in mouse intestinal muscle strips. Contractions induced by denatonium benzoate (DB) in gastric fundus were mediated via increases in intracellular Ca2+ release and extracellular Ca2+-influx, partially masked by a hyperpolarizing K+-efflux. Intra-gastric administration of DB in mice induced a TAS2R-dependent delay in gastric emptying. In hGSMC, bitter compounds evoked Ca2+-rises and increased ERK-phosphorylation. Healthy volunteers showed an impaired fundic relaxation in response to nutrient infusion and a decreased nutrient volume tolerance and increased satiation during an oral nutrient challenge test after intra-gastric DB administration. These findings suggest a potential role for intestinal TAS2Rs as therapeutic targets to alter gastrointestinal motility and hence to interfere with hunger signalling. PMID:26541810

  8. An Optimised Aqueous Extract of Phenolic Compounds from Bitter Melon with High Antioxidant Capacity

    PubMed Central

    Tan, Sing Pei; Stathopoulos, Costas; Parks, Sophie; Roach, Paul

    2014-01-01

    Bitter melon (Momordica charantia L.) is a tropical fruit claimed to have medicinal properties associated with its content of phenolic compounds (TPC). The aim of the study was to compare water with several organic solvents (acetone, butanol, methanol and 80% ethanol) for its efficiency at extracting the TPC from freeze-dried bitter melon powder. The TPC of the extracts was measured using the Folin-Ciocalteu reagent and their antioxidant capacity (AC) was evaluated using three assays. Before optimisation, the TPC and AC of the aqueous extract were 63% and 20% lower, respectively, than for the best organic solvent, 80% ethanol. However, after optimising for temperature (80 °C), time (5 min), water-to-powder ratio (40:1 mL/g), particle size (1 mm) and the number of extractions of the same sample (1×), the TPC and the AC of the aqueous extract were equal or higher than for 80% ethanol. Furthermore, less solvent (40 mL water/g) and less time (5 min) were needed than was used for the 80% ethanol extract (100 mL/g for 1 h). Therefore, this study provides evidence to recommend the use of water as the solvent of choice for the extraction of the phenolic compounds and their associated antioxidant activities from bitter melon. PMID:26785242

  9. Independent, reciprocal neuromodulatory control of sweet and bitter taste sensitivity during starvation in Drosophila

    PubMed Central

    Inagaki, Hidehiko K.; Panse, Ketaki; Anderson, David J.

    2015-01-01

    SUMMARY An organism’s behavioral decisions often depend upon the relative strength of appetitive and aversive sensory stimuli, the relative sensitivity to which can be modified by internal states like hunger. However, whether sensitivity to such opposing influences is modulated in a unidirectional or bidirectional manner is not clear. Starved flies exhibit increased sugar and decreased bitter sensitivity. It is widely believed that only sugar sensitivity changes, and that this masks bitter sensitivity. Here we use gene- and circuit-level manipulations to show that sweet- and bitter-sensitivity are independently and reciprocally regulated by starvation in Drosophila. We identify orthogonal neuromodulatory cascades that oppositely control peripheral taste sensitivity for each modality. Moreover, these pathways are recruited at increasing hunger levels, such that low-risk changes (higher sugar sensitivity) precede high-risk changes (lower sensitivity to potentially toxic resources). In this way, state intensity-dependent, reciprocal regulation of appetitive and aversive peripheral gustatory sensitivity permits flexible, adaptive feeding-decisions. PMID:25451195

  10. Birds Generally Carry a Small Repertoire of Bitter Taste Receptor Genes.

    PubMed

    Wang, Kai; Zhao, Huabin

    2015-09-01

    As they belong to the most species-rich class of tetrapod vertebrates, birds have long been believed to possess an inferior taste system. However, the bitter taste is fundamental in birds to recognize dietary toxins (which are typically bitter) in potential food sources. To characterize the evolution of avian bitter taste receptor genes (Tas2rs) and to test whether dietary toxins have shaped the repertoire size of avian Tas2rs, we examined 48 genomes representing all but 3 avian orders. The total number of Tas2r genes was found to range from 1 in the domestic pigeon to 12 in the bar-tailed trogon, with an average of 4, which suggested that a much smaller Tas2r gene repertoire exists in birds than in other vertebrates. Furthermore, we uncovered a positive correlation between the number of putatively functional Tas2rs and the abundance of potential toxins in avian diets. Because plant products contain more toxins than animal tissues and insects release poisonous defensive secretions, we hypothesized that herbivorous and insectivorous birds may demand more functional Tas2rs than carnivorous birds feeding on noninsect animals. Our analyses appear to support this hypothesis and highlight the critical role of taste perception in birds. PMID:26342138

  11. Methanolic extracts of bitter melon inhibit colon cancer stem cells by affecting energy homeostasis and autophagy.

    PubMed

    Kwatra, Deep; Subramaniam, Dharmalingam; Ramamoorthy, Prabhu; Standing, David; Moran, Elizabeth; Velayutham, Ravichandiran; Mitra, Ashim; Umar, Shahid; Anant, Shrikant

    2013-01-01

    Bitter melon fruit is recommended in ancient Indian and Chinese medicine for prevention/treatment of diabetes. However its effects on cancer progression are not well understood. Here, we have determined the efficacy of methanolic extracts of bitter melon on colon cancer stem and progenitor cells. Both, whole fruit (BMW) and skin (BMSk) extracts showed significant inhibition of cell proliferation and colony formation, with BMW showing greater efficacy. In addition, the cells were arrested at the S phase of cell cycle. Moreover, BMW induced the cleavage of LC3B but not caspase 3/7, suggesting that the cells were undergoing autophagy and not apoptosis. Further confirmation of autophagy was obtained when western blots showed reduced Bcl-2 and increased Beclin-1, Atg 7 and 12 upon BMW treatment. BMW reduced cellular ATP levels coupled with activation of AMP activated protein kinase; on the other hand, exogenous additions of ATP lead to revival of cell proliferation. Finally, BMW treatment results in a dose-dependent reduction in the number and size of colonospheres. The extracts also decreased the expression of DCLK1 and Lgr5, markers of quiescent, and activated stem cells. Taken together, these results suggest that the extracts of bitter melon can be an effective preventive/therapeutic agent for colon cancer. PMID:23533514

  12. Structural and Sensory Characterization of Bitter Tasting Steroidal Saponins from Asparagus Spears (Asparagus officinalis L.).

    PubMed

    Dawid, Corinna; Hofmann, Thomas

    2012-12-01

    Application of sequential solvent extraction and iterative chromatographic separation in combination with taste dilution analysis recently revealed a series of steroidal saponins as the key contributors to the typical bitter taste of white asparagus spears (Asparagus officinalis L.). Besides six previously reported saponins, (25R)-furost-5-en-3β,22,26-triol-3-O-[α-L-rhamnopyranosyl-(1→4)-β-D-glucopyranoside]-26-O-β-D-glucopyranoside, (25R)-furostane-3β,22,26-triol-3-O-[α-L-rhamnopyranosyl-(1→4)-β-D-glucopyranoside]-26-O-β-D-glucopyranoside, and (25S)-furostane-3β,22,26-triol-3-O-[α-L-rhamnopyranosyl-(1→4)-β-D-glucopyranoside]-26-O-β-D-glucopyranoside, and 3-O-[{α-L-rhamnopyranosyl-(1→2)}{α-L-rhamnopyranosyl-(1→4)}-β-D-glucopyranosyl]-(25S)-spirost-5-ene-3β-ol were identified for the first time as key bitter compounds in the edible spears of white asparagus by means of LC-MS/MS, LC-TOF-MS, 1D/2D-NMR spectroscopy, and hydrolysis experiments. This paper presents the isolation, structure determination, and sensory activity of these saponins. Depending on their chemical structure, the saponins identified showed human bitter recognition thresholds between 10.9 and 199.7 μmol/L (water). PMID:23137023

  13. Expression of bitter taste receptor Tas2r105 in mouse kidney.

    PubMed

    Liu, Xin; Gu, Fu; Jiang, Li; Chen, Fuxue; Li, Feng

    2015-03-20

    The kidney is the most important excretory organ in the body and plays an essential role in maintaining homeostasis in vivo by conserving body fluid and electrolytes and removing metabolic waste. In this study, three types of transgenic system were used to investigate the expression of the bitter taste receptor Tas2r105 in mouse renal tissue (Tas2r105-GFP/Cre, Tas2r105-GFP/Cre-DTA and Tas2r105-GFP/Cre-LacZ). The results suggest that bitter taste receptors Tas2r105 and Tas2r106 are expressed in the renal corpuscle and the renal tubule, including the proximal tubule and distal tubule. Expression of α-gustducin, an important component of taste signal transduction, was also detected in mouse kidney. Meanwhile, conditional diphtheria toxin (DTA) expression in Tas2r105+ cells caused an increase in size of the glomerulus and renal tubule, accompanied by a decrease in cell density in the glomerulus. This indicates that Tas2r105+ cells play an important role in maintaining the structure of the glomerulus and renal tubules. Overall, the current study collectively demonstrates that cells labeled by bitter taste receptor expression may play a critical role in controlling human health, and have properties far beyond the original concept of taste perception. PMID:25681767

  14. Depletion of bitter taste transduction leads to massive spermatid loss in transgenic mice.

    PubMed

    Li, Feng; Zhou, Minliang

    2012-06-01

    Bitter taste perception is an important sensory input warning against the ingestion of toxic and noxious substances. Bitter receptors, a family of ~30 highly divergent G-protein-coupled receptors, are exclusively expressed in taste receptor cells that contain the G-protein α-subunit gustducin, bind to α-gustducin in vitro, and respond to bitter tastes in functional expression assays. We generated a taste receptor type 2 member 5 (T2R5)-Cre/green fluorescent protein reporter transgenic mouse to investigate the tissue distribution of T2R5. Our results showed that Cre gene expression in these mice was faithful to the expression of T2R5 in taste tissue. More surprisingly, immunostaining and X-gal staining revealed T2R5 expression in the testis. Ablation of T2R5 + cells led to a smaller testis and removed the spermatid phase from most of the seminiferous tubules. The entire taste transduction cascade (α-gustducin, Ggamma13, phospholipase Cβ2) was detected in spermatogenesis, whereas transient receptor potential, cation channel subfamily M member 5 (Trpm5), was observed only in the later spermatid phase. In short, our results indicate that the taste transduction cascade may be involved in spermatogenesis. PMID:22266327

  15. Acetaminophen-containing chewable tablets with suppressed bitterness and improved oral feeling.

    PubMed

    Suzuki, Hiroyuki; Onishi, Hiraku; Hisamatsu, Seiji; Masuda, Kosuke; Takahashi, Yuri; Iwata, Masanori; Machida, Yoshiharu

    2004-06-18

    The aim of this study was to develop acetaminophen chewable tablets with suppressed bitterness and improved oral feeling by examination of hard fats as the matrix base and of sweetening agents as corrigents. Witepsol H-15, W-35, S-55, E-75 and E-85, and Witocan H and 42/44 were used as hard fats. Witocan H and 42/44 were selected in view of improved oral feeling. Witocan H/Witocan 42/44 mixture tablets showed different melting characteristics and drug release rates dependent on their ratios, and those with the Witocan H/Witocan 42/44 ratio of 92.5% (w/w) and more showed good drug release. Sucrose, xylitol, saccharin, saccharin sodium, aspartame and sucralose were used as sweetening agents, and applied alone or with Benecoat BMI-40 or cocoa powder. The Witocan H tablet with 1% (w/w) saccharin plus 5% (w/w) Benecoat BMI-40 (Sc1-B5), and the Witocan H/Witocan 42/44 (92.5:7.5, w/w) mixture tablet with 1% (w/w) aspartame plus 5% (w/w) Benecoat BMI-40 suppressed bitterness and sweetness excellently, but the former tablet showed better drug release. Thus, the Witocan H tablet with Sc1-B5 is suggested as the best acetaminophen chewable tablet, exhibiting suppressed bitterness, low sweetness, improved oral feeling and good drug release.

  16. Sequence Analysis of Bitter Taste Receptor Gene Repertoires in Different Ruminant Species.

    PubMed

    Monteiro Ferreira, Ana; Tomás Marques, Andreia; Bhide, Mangesh; Cubric-Curik, Vlatka; Hollung, Kristin; Knight, Christopher Harold; Raundrup, Katrine; Lippolis, John; Palmer, Mitchell; Sales-Baptista, Elvira; Araújo, Susana Sousa; de Almeida, André Martinho

    2015-01-01

    Bitter taste has been extensively studied in mammalian species and is associated with sensitivity to toxins and with food choices that avoid dangerous substances in the diet. At the molecular level, bitter compounds are sensed by bitter taste receptor proteins (T2R) present at the surface of taste receptor cells in the gustatory papillae. Our work aims at exploring the phylogenetic relationships of T2R gene sequences within different ruminant species. To accomplish this goal, we gathered a collection of ruminant species with different feeding behaviors and for which no genome data is available: American bison, chamois, elk, European bison, fallow deer, goat, moose, mouflon, muskox, red deer, reindeer and white tailed deer. The herbivores chosen for this study belong to different taxonomic families and habitats, and hence, exhibit distinct foraging behaviors and diet preferences. We describe the first partial repertoires of T2R gene sequences for these species obtained by direct sequencing. We then consider the homology and evolutionary history of these receptors within this ruminant group, and whether it relates to feeding type classification, using MEGA software. Our results suggest that phylogenetic proximity of T2R genes corresponds more to the traditional taxonomic groups of the species rather than reflecting a categorization by feeding strategy. PMID:26061084

  17. Sources of nitrate in water from springs and the Upper Floridan aquifer, Suwannee River basin, Florida

    USGS Publications Warehouse

    Katz, B.G.; Hornsby, H.D.; Bohlke, J.F.

    1999-01-01

    In the Suwannee River basin of northern Florida, nitrate-N concentrations are 1.5 to 20 mg 1-1 in waters of the karstic Upper Floridan aquifer and in springs that discharge into the middle reach of the Suwannee River. During 1996-1997, fertilizers and animal wastes from farming operations in Suwannee County contributed approximately 49% and 45% of the total N input, respectively. Values of ??15N-NO3 in spring waters range from 3.9??? to 5.8???, indicating that nitrate most likely originates from a mixture of inorganic (fertilizers) and organic (animal waste) sources. In Lafayette County, animal wastes from farming operations and fertilizers contributed approximately 53% and 39% of the total N input, respectively, but groundwater near dairy and poultry farms has ??15N-NO3 values of 11.0-12.1???, indicative of an organic source of nitrate. Spring waters that discharge to the Suwannee River from Lafayette County have ??15N-NO3 values of 5.4-8.39???, which are indicative of both organic and inorganic sources. Based on analyses of CFCs, the mean residence time of shallow groundwater and spring water ranges between 8-12 years and 12-25 years, respectively.

  18. Imaging Karst Aquifers with Multichannel Seismic Data in Biscayne Bay: Conventional Wisdom Defied

    NASA Astrophysics Data System (ADS)

    Walker, C.; Cunningham, K. J.

    2008-05-01

    Conventional wisdom reasons that acquisition of useful seismic data in shallow-marine carbonate environments is not possible because: (1) water-bottom multiples will dominate; (2) receiver offsets will be too short to image deep reflectors; (3) normal move out is too small to effectively calculate velocities; (4) air-gun source arrays are not appropriate or frequency band-limited; and (5) it is folly to over-sample the seismic data and process very large digital data sets. In 2007, about 108 km (17 individual profiles) of marine, multichannel, high-resolution, seismic data were acquired almost entirely inside Biscayne National Park in water depths ranging from 0.9 to 100 m. The data were collected using a 48-trace, towed-streamer array; an interdependent air-gun as the seismic source; and a proprietary 52-channel, 24-bit recording system. The seismic vessel was a fast, shallow-draft catamaran capable of continuously acquiring data in water as shallow as 0.7 m. The set of seismic images from 17 profiles show well-defined reflections from near surface to the Eocene Oldsmar Formation (including the karstic Boulder Zone in the Lower Floridan aquifer). The profiles also display distinctive geologic features that include karst, clinoformal prograding strata, unconformities, fractures, stratal truncation, and evidence for breaching of confining units.

  19. Hydrogeology, water quality, and potential for contamination of the Upper Floridan aquifer in the Silver Springs ground-water basin, central Marion County, Florida

    USGS Publications Warehouse

    Phelps, G.G.

    1994-01-01

    The Upper Floridan aquifer, composed of a thick sequence of very porous limestone and dolomite, is the principal source of water supply in the Silver Springs ground-water basin of central Marion County, Florida. The karstic nature of the local geology makes the aquifer susceptible to contaminants from the land surface. Contaminants can enter the aquifer by seepage through surficial deposits and through sinkholes and drainage wells. Potential contaminants include agricultural chemicals, landfill leachates and petroleum products from leaking storage tanks and accidental spills. More than 560 sites of potential contamination sources were identified in the basin in 1990. Detailed investigation of four sites were used to define hydrologic conditions at representative sites. Ground-water flow velocities determined from dye trace studies ranged from about 1 foot per hour under natural flow conditions to about 10 feet per hour under pumping conditions, which is considerably higher than velocities estimated using Darcy's equation for steady-state flow in a porous medium. Water entering the aquifer through drainage wells contained bacteria, elevated concentrations of nutrients, manganese and zinc, and in places, low concentrations of organic compounds. On the basis of results from the sampling of 34 wells in 1989 and 1990, and from the sampling of water entering the Upper Floridan aquifer through drainage wells, there has been no widespread degradation of water quality in the study area. In an area of karst, particularly one in which fracture flow is significant, evaluating the effects from contaminants is difficult and special care is required when interpolating hydrogeologic data from regional studies to a specific. (USGS)

  20. The influence of subaquatic springs in lacustrine sedimentation: Origin and paleoenvironmental significance of homogenites in karstic Lake Banyoles (NE Spain)

    NASA Astrophysics Data System (ADS)

    Morellón, Mario; Anselmetti, Flavio S.; Valero-Garcés, Blas; Giralt, Santiago; Ariztegui, Daniel; Sáez, Alberto; Mata, M. Pilar; Barreiro-Lostres, Fernando; Rico, Mayte; Moreno, Ana

    2014-08-01

    Banyoles (42°08‧N, 2°45‧E) is the largest and deepest lake of karstic-tectonic origin in the Iberian Peninsula. The lake comprises two basins and six sub-circularly shaped sub-basins fed by subaquatic springs. Periods of intense groundwater inflow in the deepest sub-basins lead to the fluidization and re-suspension of previously deposited sediments and subsequent settling forming homogenite deposits on the southern basin intermediate platforms. The multiproxy analysis of sediment cores combined with high resolution seismic stratigraphy (3.5 kHz pinger and multi-frequency Chirp surveys) allows a precise reconstruction of depositional environments and related hydrological variability and groundwater inflow during the last ca. 7.6 cal kyr BP. According to the age model based on 137Cs, 210Pb and AMS 14C dating, homogenite deposition occurred between 7.2 and 5.5 cal kyr BP, stopped during the middle Holocene (5.5-2.8 cal kyr BP) and greatly increased during the last two millennia with a total of 17 homogenite layers individually up to 75 cm-thick. The onset of this unique sedimentation mode at ca. 3 cal kyr BP coincides with an increase in lake level, evidenced by the onlapping of fine-grained, distal sediments over coarser massive, carbonate-rich, littoral deposits. A detailed, multidisciplinary study of the homogenites (sedimentology, physical properties, high-resolution elemental geochemistry, mineral composition, grain-size, organic matter content and SEM) combined with seismic stratigraphy demonstrates that the fluidization events triggering the formation of the homogenites were caused by higher and more intense local groundwater inflow, related to increased rainfall during the Late Holocene and likely intensified by land use changes during the last millennium.

  1. Actinobacteria Isolated from an Underground Lake and Moonmilk Speleothem from the Biggest Conglomeratic Karstic Cave in Siberia as Sources of Novel Biologically Active Compounds

    PubMed Central

    Tokovenko, Bogdan T.; Protasov, Eugeniy S.; Gamaiunov, Stanislav V.; Rebets, Yuriy V.; Luzhetskyy, Andriy N.; Timofeyev, Maxim A.

    2016-01-01

    Actinobacteria isolated from unstudied ecosystems are one of the most interesting and promising sources of novel biologically active compounds. Cave ecosystems are unusual and rarely studied. Here, we report the isolation and characterization of ten new actinobacteria strains isolated from an ancient underground lake and moonmilk speleothem from the biggest conglomeratic karstic cave in Siberia with a focus on the biological activity of the obtained strains and the metabolite dereplication of one active strain. Streptomyces genera isolates from moonmilk speleothem demonstrated antibacterial and antifungal activities. Some of the strains were able to inhibit the growth of pathogenic Candida albicans. PMID:26901168

  2. Actinobacteria Isolated from an Underground Lake and Moonmilk Speleothem from the Biggest Conglomeratic Karstic Cave in Siberia as Sources of Novel Biologically Active Compounds.

    PubMed

    Axenov-Gribanov, Denis V; Axenov-Gibanov, Denis V; Voytsekhovskaya, Irina V; Tokovenko, Bogdan T; Protasov, Eugeniy S; Gamaiunov, Stanislav V; Rebets, Yuriy V; Luzhetskyy, Andriy N; Timofeyev, Maxim A

    2016-01-01

    Actinobacteria isolated from unstudied ecosystems are one of the most interesting and promising sources of novel biologically active compounds. Cave ecosystems are unusual and rarely studied. Here, we report the isolation and characterization of ten new actinobacteria strains isolated from an ancient underground lake and moonmilk speleothem from the biggest conglomeratic karstic cave in Siberia with a focus on the biological activity of the obtained strains and the metabolite dereplication of one active strain. Streptomyces genera isolates from moonmilk speleothem demonstrated antibacterial and antifungal activities. Some of the strains were able to inhibit the growth of pathogenic Candida albicans. PMID:26901168

  3. The marked inhibition of the bitter taste of Polymyxin B sulfate and trimethoprim x sulfamethoxazole by flavored BMI-60 in pediatric patients.

    PubMed

    Saito, M; Hoshi, M; Igarashi, A; Ogata, H; Edo, K

    1999-09-01

    Taste acceptability of ground Polymyxin B sulfate and Bactramin C tablets was examined when flavored BMI-60, a food additive, was added. Both adult and child volunteers found the bitter taste of the two drugs markedly inhibited, making it clinically useful. Noncompliance, due to this bitterness, was improved using flavored BMI-60. The most striking characteristic of flavored BMI-60 is the ease of preparation compared with the manufacture of other hospital pharmaceuticals such as jelly, gummi and candy done to mask bitterness.

  4. ANALYTICAL ELEMENT MODELING OF COASTAL AQUIFERS

    EPA Science Inventory

    Four topics were studied concerning the modeling of groundwater flow in coastal aquifers with analytic elements: (1) practical experience was obtained by constructing a groundwater model of the shallow aquifers below the Delmarva Peninsula USA using the commercial program MVAEM; ...

  5. Groundwater Flow in the Arthur Marble Aquifer, New Zealand

    NASA Astrophysics Data System (ADS)

    Stewart, M. K.

    2008-05-01

    Arthur Marble underlies the Takaka Valley and outcrops in Karst Uplands to east and west of the valley in the South Island of New Zealand. It is the principal groundwater aquifer in the region and host to the remarkable Waikoropupu Springs near the coast. With average flow of 13,300 L/s, the karstic springs have many interesting features including unusual size and clarity. This work uses rainfall and river level, natural tracer and chemical measurements to determine the recharge sources and nature of the flow system in the Arthur Marble Aquifer (AMA). Total recharge to the AMA of 19,750 L/s comes from three sources (Karst Uplands stream seepage, Takaka River seepage and Takaka Valley rainfall infiltration). Since 13,300 L/s is discharged at the springs, the remainder must escape via offshore springs (6,450 L/s). The oxygen-18 mass balance allows the contribution of each source to each spring to be determined; most of the flow to the Main Spring of the Waikoropupu Springs comes from the Karst Uplands. The offshore springs are mostly fed from the Takaka River. The chemical concentrations of the Main Spring show input of 0.5% of sea water on average, but varying with flow. This variation with flow shows that two water components (sea-water-bearing and non-sea-water-bearing) contribute to the spring's discharge. Tritium measurements spanning 40 years, and CFC-11 measurements, give a mean residence time of 8 years for the Main Spring water using the preferred two-component model. Our conceptual flow model, based on the flow, oxygen-18, chloride and tritium measurements, reveals that two different flow systems with different recharge sources are needed to explain the flow within the AMA. One system contains deeply penetrating old water with mean age 10.2 years and water volume 3 cubic kilometers, recharged from the Karst Uplands. The other, at shallow levels below the valley floor, has much younger water, with mean age 1.2 years and water volume 0.4 cubic kilometers

  6. 40 CFR 147.1352 - Aquifer exemptions.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 23 2014-07-01 2014-07-01 false Aquifer exemptions. 147.1352 Section 147.1352 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS... Aquifer exemptions. Those portions of aquifers within one-quarter mile of existing Class II wells...

  7. 40 CFR 147.1352 - Aquifer exemptions.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 23 2011-07-01 2011-07-01 false Aquifer exemptions. 147.1352 Section 147.1352 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS... Aquifer exemptions. Those portions of aquifers within one-quarter mile of existing Class II wells...

  8. 40 CFR 147.1352 - Aquifer exemptions.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 24 2013-07-01 2013-07-01 false Aquifer exemptions. 147.1352 Section 147.1352 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS... Aquifer exemptions. Those portions of aquifers within one-quarter mile of existing Class II wells...

  9. 40 CFR 147.1352 - Aquifer exemptions.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 24 2012-07-01 2012-07-01 false Aquifer exemptions. 147.1352 Section 147.1352 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS... Aquifer exemptions. Those portions of aquifers within one-quarter mile of existing Class II wells...

  10. 40 CFR 147.1352 - Aquifer exemptions.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 22 2010-07-01 2010-07-01 false Aquifer exemptions. 147.1352 Section 147.1352 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS... Aquifer exemptions. Those portions of aquifers within one-quarter mile of existing Class II wells...

  11. Potentiometric surface of the upper Floridan Aquifer in the St. Johns River Water Management District and vicinity, May 1995

    USGS Publications Warehouse

    Knowles, Leel; O'Reilly, A. M.; Phelps, G.G.; Bradner, L.A.

    1995-01-01

    This map depicts the potentiometric surface of the Upper Floridan aquifer in the St. Johns River Water Management District and vicinity for May 1995. The map is based on water-level measurements made at more than 900 wells and springs. Approximately 30 new wells were added to better define the potentiometric surface mainly in the northwest area of the map. Data on the map were contoured using 5-foot contour intervals in most areas. Two new wells located north of Rainbow Springs indicate a slight northward extension of the depressed area surrounding the springs. Several new wells in Bradford County indicate a slight reduction in the size of the potentiometric-surface high along the northwest edge of the county. The potentiometric surface of this karstic aquifer generally reflects land surface topography. Potentiometric-surface highs often correspond to topographic highs, which are areas of recharge to the Upper Floridan aquifer. Springs within topographic lows along with areas of more diffuse upward leakage are natural zones of discharge. Municipal, agricultural, and industrial withdrawals have lowered the potentiometric surface in some areas. The potentiometric surface ranged from 127 feet above sea level in Polk County to 84 feet below sea level in southeast Georgia near the St. Marys River. Water levels measured in May 1995 generally were about 0 to 4 feet higher than those measured in May 1994 except in St. Lucie County and near Rainbow Springs, where levels were 1 to 3 feet lower. Generally, May 1995 water levels were 0 to 5 feet lower than levels in September 1994, except near Orlando, where levels were 6 to 12 feet lower, and across the northwest corner of the map area which includes Marion, Alachua, Bradford, Baker, and Nassau Counties, north and west Duval County, and south Georgia. (USGS)

  12. Relation between "terra rossa" from the Apulia aquifer of Italy and the radon content of groundwater: Experimental results and their applicability to radon occurrence in the aquifer

    NASA Astrophysics Data System (ADS)

    Tadolini, T.; Spizzico, M.

    The radon-222 (222Rn) activity in groundwater of the Apulian karstic aquifer in southern Italy is as great as 500 Becquerel per liter (Bq/L) locally. Normal radium-226 (226Ra) activity in the limestone and calcareous dolomites of the aquifer is not enough to explain such a high level. Laboratory investigations identified high 226Ra activity in the "terra rossa," the residuum occupying fissures and cavities in the bedrock, and also the relation between (1) 226Ra-bearing bedrock and "terra rossa" and (2) 222Rn in water. The "terra rossa" is the primary source of the radon in the groundwater. The experimental results show the need to characterize the "terra rossa" of Apulia on the basis of 226Ra activity and also to study the distribution and variations in 222Rn activity over time in the aquifer. Résumé L'activité du radon-222 (222Rn) dans les eaux souterraines de l'aquifère karstique des Pouilles, dans le sud de l'Italie, atteint localement 500 Becquerel par litre (Bq/L). L'activité normale du radium-226 (226Ra) dans les calcaires et dans les calcaires dolomitiques de l'aquifère n'est pas assez élevée pour expliquer des valeurs aussi élevées. Des analyses de laboratoire ont mis en évidence une forte activité en 226Ra dans la terra rossa, remplissage de fissures et de cavités de la roche, ainsi qu'une relation entre (1) la roche et la terra rossa contenant du 226Ra et (2) le 222Rn dans l'eau. La terra rossa est la source primaire de radon dans l'eau souterraine. Les résultats expérimentaux montrent qu'il est nécessaire de caractériser la terra rossa des Pouilles par son activité en 226Ra et d'étudier la distribution et les variations de l'activité en 222Rn au cours du temps dans l'aquifère. Resumen La actividad del radon-222 (222Rn) en el agua subterránea del acuífero cárstico de Apulia, al sur de Italia, alcanza localmente los 500Bq/L. La actividad normal del radio-226 (226Ra) en las calcitas y dolomitas del acuífero no es suficiente para

  13. [Comparative analysis of ergogenic efficacy of energy drinks components (caffeine and bitter orange extract) in combination with alcohol].

    PubMed

    Anuchin, A M; Iuvs, G G

    2014-01-01

    Estimation of ergogenic effects of caffeine and bitter orange exract combined with alcohol is presented in the article. Investigations were performed on 3 groups (8 animals in each group) of male Wistar rats aged 4 months. Animals in group 1 were treated orally for 7 days, the mixture comprising caffeine and alcohol (0.6 g of caffeine, 72 ml of ethanol, water to 1 liter) in an amount equivalent to 4.28 mg caffeine per kg of body weight. Animals in group 2 received a mixture containing bitter orange extract and alcohol (1 g bitter orange extract, 72 ml of ethanol, water to 1 liter) in an amount equivalent to 0.43 mg of synephrine per kg body weight. Animals in the control group received the same volume (7.1 ml/kg) 7.2% aqueous solution of ethanol. Group of animals consumed caffeine in mixture with alcohol and the control group exhibited a significant weight gain, while the body weight of animals treated with the extract of bitter orange didn't significantly change. Using the methodology of the open field the effects of caffeine and bitter orange extract in combination with alcohol on the ratio of the active components of the orienting-exploratory behavior and passive-defensive behavior have been determined. Administration of mixture with caffeine increased locomotory activity by 164%, administration of bitter orange extract didn't affect this performance. Introduction of caffeine containing mixture significantly reduced the level of situational anxiety, which was manifested in the reduction of time spent by the animal in the center of the arena. The effects of ergogenic components on the performance of static and dynamic muscle endurance have been investigated. Single administration of the mixture containing caffeine, after 30 min caused a significant increase in performance and, consequently, endurance of glycolytic muscle fibers measured using the "inverted grid" test. Animals from this group produced 186% more work compared with control animals. Acute

  14. [Comparative analysis of ergogenic efficacy of energy drinks components (caffeine and bitter orange extract) in combination with alcohol].

    PubMed

    Anuchin, A M; Iuvs, G G

    2014-01-01

    Estimation of ergogenic effects of caffeine and bitter orange exract combined with alcohol is presented in the article. Investigations were performed on 3 groups (8 animals in each group) of male Wistar rats aged 4 months. Animals in group 1 were treated orally for 7 days, the mixture comprising caffeine and alcohol (0.6 g of caffeine, 72 ml of ethanol, water to 1 liter) in an amount equivalent to 4.28 mg caffeine per kg of body weight. Animals in group 2 received a mixture containing bitter orange extract and alcohol (1 g bitter orange extract, 72 ml of ethanol, water to 1 liter) in an amount equivalent to 0.43 mg of synephrine per kg body weight. Animals in the control group received the same volume (7.1 ml/kg) 7.2% aqueous solution of ethanol. Group of animals consumed caffeine in mixture with alcohol and the control group exhibited a significant weight gain, while the body weight of animals treated with the extract of bitter orange didn't significantly change. Using the methodology of the open field the effects of caffeine and bitter orange extract in combination with alcohol on the ratio of the active components of the orienting-exploratory behavior and passive-defensive behavior have been determined. Administration of mixture with caffeine increased locomotory activity by 164%, administration of bitter orange extract didn't affect this performance. Introduction of caffeine containing mixture significantly reduced the level of situational anxiety, which was manifested in the reduction of time spent by the animal in the center of the arena. The effects of ergogenic components on the performance of static and dynamic muscle endurance have been investigated. Single administration of the mixture containing caffeine, after 30 min caused a significant increase in performance and, consequently, endurance of glycolytic muscle fibers measured using the "inverted grid" test. Animals from this group produced 186% more work compared with control animals. Acute

  15. DNA Sequence and Expression Variation of Hop (Humulus lupulus) Valerophenone Synthase (VPS), a Key Gene in Bitter Acid Biosynthesis

    PubMed Central

    Castro, Consuelo B.; Whittock, Lucy D.; Whittock, Simon P.; Leggett, Grey; Koutoulis, Anthony

    2008-01-01

    Background The hop plant (Humulus lupulus) is a source of many secondary metabolites, with bitter acids essential in the beer brewing industry and others having potential applications for human health. This study investigated variation in DNA sequence and gene expression of valerophenone synthase (VPS), a key gene in the bitter acid biosynthesis pathway of hop. Methods Sequence variation was studied in 12 varieties, and expression was analysed in four of the 12 varieties in a series across the development of the hop cone. Results Nine single nucleotide polymorphisms (SNPs) were detected in VPS, seven of which were synonymous. The two non-synonymous polymorphisms did not appear to be related to typical bitter acid profiles of the varieties studied. However, real-time quantitative reverse-transcription polymerase chain reaction (qRT-PCR) analysis of VPS expression during hop cone development showed a clear link with the bitter acid content. The highest levels of VPS expression were observed in two triploid varieties, ‘Symphony’ and ‘Ember’, which typically have high bitter acid levels. Conclusions In all hop varieties studied, VPS expression was lowest in the leaves and an increase in expression was consistently observed during the early stages of cone development. PMID:18519445

  16. Breeding of 'Manten-Kirari', a non-bitter and trace-rutinosidase variety of Tartary buckwheat (Fagopyrum tataricum Gaertn.).

    PubMed

    Suzuki, Tatsuro; Morishita, Toshikazu; Mukasa, Yuji; Takigawa, Shigenobu; Yokota, Satoshi; Ishiguro, Koji; Noda, Takahiro

    2014-12-01

    Here, we developed a new Tartary buckwheat cultivar 'Manten-Kirari', whose flour contains only trace amounts of rutinosidase and lacked bitterness. The trace-rutinosidase breeding line 'f3g-162' (seed parent), which was obtained from a Nepalese genetic resource, was crossed with 'Hokkai T8' (pollen parent), the leading variety in Japan, to improve its agronomic characteristics. The obtained progeny were subjected to performance test. 'Manten-Kirari' had no detectable rutinosidase isozymes in an in-gel detection assay and only 1/266 of the rutinosidase activity of 'Hokkai T8'. Dough prepared from 'Manten-Kirari' flour contained almost no hydrolyzed rutin, even 6 h after the addition of water, whereas the rutin in 'Hokkai T8' dough was completely hydrolyzed within 10 min. In a sensory evaluation of the flour from the two varieties, nearly all panelists detected strong bitterness in 'Hokkai T8', whereas no panelists reported bitterness in 'Manten-Kirari'. This is the first report to describe the breeding of a Tartary buckwheat cultivar with reduced rutin hydrolysis and no bitterness in the prepared flour. Notably, the agronomic characteristics of 'Manten-Kirari' were similar to those of 'Hokkai T8', which is the leading variety in Japan. Based on these characteristics, 'Manten-Kirari' is a promising for preparing non-bitter, rutin-rich foods.

  17. Psychophysical Effects of Increasing Oil Concentrations on Saltiness and Bitterness Perception of Oil-in-Water Emulsions.

    PubMed

    Torrico, Damir Dennis; Prinyawiwatkul, Witoon

    2015-08-01

    Limited research has been done to investigate saltiness and bitterness perceptions of NaCl, KCl, and caffeine in emulsion systems. Saltiness and bitterness intensities of emulsions prepared with different concentrations of oil [0% (that is, solution), 20%, 40%, canola oil] and different concentrations of 3 tastants (NaCl [0.5% to 1.0%], KCl [0.5% to 1.5%], and caffeine [0.05 to 0.15%]) were measured using the Spectrum™ descriptive method (N = 16) and the Electronic-tongue (E-tongue). Linear regression and the Stevens' power law were used to model the taste intensities against the tastant concentrations. From the descriptive data, saltiness intensities in emulsions were higher than solutions, demonstrating a saltiness-enhancing effect imparted by oil. Bitterness intensities in emulsions were lower compared to those of solutions for caffeine, but they were similar for KCl. This demonstrated that oil suppressed bitterness for caffeine. E-tongue saltiness measurements were corresponding to those of the descriptive data; however, E-tongue bitterness intensities of KCl showed an opposite pattern.

  18. Hydrogeological Mapping and Hydrological Process Modelling for understanding the interaction of surface runoff and infiltration in a karstic catchment

    NASA Astrophysics Data System (ADS)

    Stadler, Hermann; Reszler, Christian; Komma, Jürgen; Poltnig, Walter; Strobl, Elmar; Blöschl, Günter

    2013-04-01

    This paper presents a study at the interface hydrogeology - hydrology, concerning mapping of surface runoff generation areas in a karstic catchment. The governing processes range from surface runoff with subsequent infiltration to direct infiltration and further deep percolation into different karst conduits. The aim is to identify areas with a potential of surface erosion and thus, identify the hazard of solute/contaminant input into the karst system during aestival thundershowers, which can affect water quality at springs draining the karst massif. According to hydrogeological methods the emphasis of the study are field investigations based on hydrogeological mapping and field measurements in order to gain extensive knowledge about processes and their spatial distribution in the catchment to establish a site specific Dominant Process Concept (DPC). Based on the hydrogeological map, which describes the lithological units relating to their hydrogeological classification, mapping focuses on the following attributes of the overlaying loose material/debris and soils: (i) infiltration capability, (ii) soil depth (as a measure for storage capacity), and (iii) potential surface flow length. Detailed mapping is performed in the reference area, where a variety of data are acquired, such as soil grain size distribution, soil moisture through TDR measurements at characteristic points, etc. The reference area borders both end-members of the dominant surface runoff processes as described above. Geomorphologic analyses based on a 1m resolution Laserscan assist in allocating sinks and flow accumulation paths in the catchment. By a regionalisation model, developed and calibrated based on the results in the reference areas, the process disposition is transposed onto the whole study area. In a further step, a hydrological model will be set up, where model structure and parameters are identified based on above described working steps and following the DPC. The model will be

  19. Description and Evaluation of Numerical Groundwater Flow Models for the Edwards Aquifer, South-Central Texas

    USGS Publications Warehouse

    Lindgren, Richard J.; Taylor, Charles J.; Houston, Natalie A.

    2009-01-01

    A substantial number of public water system wells in south-central Texas withdraw groundwater from the karstic, highly productive Edwards aquifer. However, the use of numerical groundwater flow models to aid in the delineation of contributing areas for public water system wells in the Edwards aquifer is problematic because of the complex hydrogeologic framework and the presence of conduit-dominated flow paths in the aquifer. The U.S. Geological Survey, in cooperation with the Texas Commission on Environmental Quality, evaluated six published numerical groundwater flow models (all deterministic) that have been developed for the Edwards aquifer San Antonio segment or Barton Springs segment, or both. This report describes the models developed and evaluates each with respect to accessibility and ease of use, range of conditions simulated, accuracy of simulations, agreement with dye-tracer tests, and limitations of the models. These models are (1) GWSIM model of the San Antonio segment, a FORTRAN computer-model code that pre-dates the development of MODFLOW; (2) MODFLOW conduit-flow model of San Antonio and Barton Springs segments; (3) MODFLOW diffuse-flow model of San Antonio and Barton Springs segments; (4) MODFLOW Groundwater Availability Modeling [GAM] model of the Barton Springs segment; (5) MODFLOW recalibrated GAM model of the Barton Springs segment; and (6) MODFLOW-DCM (dual conductivity model) conduit model of the Barton Springs segment. The GWSIM model code is not commercially available, is limited in its application to the San Antonio segment of the Edwards aquifer, and lacks the ability of MODFLOW to easily incorporate newly developed processes and packages to better simulate hydrologic processes. MODFLOW is a widely used and tested code for numerical modeling of groundwater flow, is well documented, and is in the public domain. These attributes make MODFLOW a preferred code with regard to accessibility and ease of use. The MODFLOW conduit-flow model

  20. Change in the structure of Escherichia coli population related to the settling velocities in karst aquifer

    NASA Astrophysics Data System (ADS)

    Petit, F.; Massei, N.; Berthe, T.; Deloffre, J.; Fournier, M.; Bertel, F.; jolivet, F.; lallemand, H.; Niepceron, F.; Sellier, C.; Benjamin, S.

    2012-04-01

    Change in the structure of Escherichia coli population related to the settling velocities in karst aquifer. Fabienne Petit1, Fanny Bertel2, Florence Jolivet2, Hélène Lallemand2, Fanny Niepceron2, Clémentine Sellier2, Benjamin Smith2, Thierry Berthe, Julien Deloffre1, Matthieu Fournier1,Nicolas Massei 1. 1- Université de Rouen, UMR 6143 M2C, 76821 Mont-Saint-Aignan, France 1- CNRS, UMR 6143 M2C, 76821 Mont-Saint-Aignan, France 1- SFR SCALE, 76821 Mont-Saint-Aignan, France 2 Research project of students from MasterEnvironment ( ESEB University of Rouen) According to the farming or human use of their watershed, the karst aquifers were particularly vulnerable to contamination by fecal bacteria mainly Escherichia coli (E. coli). To date, if E. coli is a commensal bacteria originated from intestinal tracts of humans and vertebrate animals, the water and sediment are also considered as a putative second habitat where some strains could be naturalized. Among the phenotypic characteristics of E.coli, association with particles not only could enhance the survival of some strains but also greatly influenced the particles dynamics. The great genetic diversity of E. coli may explain this variety of lifestyles of this bacteria species. Indeed we have previously shown that in river, the structure of the population of E. coli was not stable, but depended on hydrological conditions (Ratajczak, 2010). In this work we go further into the understanding of the behaviour of E. coli population in karstic hydrosystem by investigating (i) the structure of E. coli population based on the distribution in four main phylo-groups (A, B1, B2, D) according their settling velocities from surface water to groundwater. For this purpose we combined microbiology , microscopy (SEM) and hydrology approaches. During their transfer along the karst hydrosystem, both modalities of the association of E. coli to the particles and, the structure of E. coli population were modified. Settling experiment led

  1. Sweet and bitter taste: structure and conformations of two aspartame dipeptide analogues.

    PubMed

    Benedetti, E; Gavuzzo, E; Santini, A; Kent, D R; Zhu, Y F; Zhu, Q; Mahr, C; Goodman, M

    1995-01-01

    The synthesis and X-ray diffraction analysis of two dipeptide taste ligands have been carried out as part of our study of the molecular basis of taste. The compounds L-aspartyl-D-alpha-methylphenylalanine methyl ester [L-Asp-D-(alpha Me)Phe-OMe] and L-aspartyl-D-alanyl-2,2,5, 5-tetramethylcyclopentanyl ester [L-Asp-D-Ala-OTMCP] elicit bitter and sweet taste, respectively. The C-terminal residues of the two analogues adopt distinctly different conformations in the solid state. The aspartyl moiety assumes the same conformation found in other dipeptide taste ligands with the side-chain carboxylate and the amino groups forming a zwitterionic ring with a conformation defined by psi, chi 1 = 157.7 degrees, -61.5 degrees for L-Asp-D-Ala-OTMCP and 151.0 degrees, -68.8 degrees for L-Asp-D-(alpha Me)Phe-OMe. In the second residue, a left-handed helical conformation is observed for the (alpha Me)Phe residue of L-Asp-D-(alpha Me)Phe-OMe with phi 2 = 49.0 degrees and psi 2 = 47.9 degrees, while the Ala residue of L-Asp-D-Ala-OTMCP adopts a semi-extended conformation characterized by dihedral angles phi 2 = 62.8 degrees and psi 2 = -139.9 degrees. The solid-state structure of the bitter L-Asp-D-(alpha Me)Phe-OMe is extended: while the crystal structure of the sweet L-Asp-D-OTMCP roughly adopts the typical L-shaped structure shown by other sweeteners. The data of L-Asp-D-(alpha Me)Phe-OMe are compared with those of its diastereoisomer L-Asp-L-(alpha Me)Phe-OMe. Conformational analysis of the two taste ligands in solution by NMR and computer simulations agrees well with our model for sweet and bitter tastes. PMID:9223014

  2. Efficacy of various techniques on biochemical characteristics and bitterness of pummelo juice.

    PubMed

    Kore, Vijaykumar T; Chakraborty, I

    2015-09-01

    The consumer acceptability of pummelo juice is affected badly due to the presence of bitter principles in it. Therefore in order to avoid such bitterness development, the extracted juice from pummelo was subjected to five different treatments like juice diffused into syrup (70°Brix), lye peeling of segments in boiling NaOH for 2-3 min, increasing the pH of juice, hot water treatment (50 °C) prior to peeling for 20 min and without any treatment (control) for suppressing the development of bitterness in the juice. Based on bio-chemical analysis, diffusion of juice into syrup (70°Brix) showed better result as compared to other treatments. The maximum amount of TSS was found in juice diffused into syrup (i. e. 45, 30 and 15°Brix) along with highest TSS/acid ratio (92.21, 49.87 and 17.53). Higher amount of acidity was observed in pH adjusted samples with 4.25, 4.50 and 4.75 respectively. However, control samples showed higher amount of ascorbic acid (73.97 mg/100 ml juice) content followed by pH adjusted samples. The highest organoleptic score for taste (8.00), colour (8.83), aroma (8.66), overall acceptability (7.88) and extent of debittering (7.50) were recorded in juice diffused into syrup 70°Brix and achieved final TSS of juice at 45, 30 and 15°Brix respectively. Moreover, the above treatment (juice diffused into syrup 70°Brix) showed promising low cost and easy to adopt technique of debittering in respect of extent of debittering and maintaining sensory quality during storage of pummel juice. PMID:26345031

  3. Matured Hop Bittering Components Induce Thermogenesis in Brown Adipose Tissue via Sympathetic Nerve Activity.

    PubMed

    Morimoto-Kobayashi, Yumie; Ohara, Kazuaki; Takahashi, Chika; Kitao, Sayoko; Wang, Guanying; Taniguchi, Yoshimasa; Katayama, Mikio; Nagai, Katsuya

    2015-01-01

    Obesity is the principal symptom of metabolic syndrome, which refers to a group of risk factors that increase the likelihood of atherosclerosis. In recent decades there has been a sharp rise in the incidence of obesity throughout the developed world. Iso-α-acids, the bitter compounds derived from hops in beer, have been shown to prevent diet-induced obesity by increasing lipid oxidation in the liver and inhibition of lipid absorption from the intestine. Whereas the sharp bitterness induced by effective dose of iso-α-acids precludes their acceptance as a nutrient, matured hop bittering components (MHB) appear to be more agreeable. Therefore, we tested MHB for an effect on ameliorating diet-induced body fat accumulation in rodents. MHB ingestion had a beneficial effect but, compared to iso-α-acids and despite containing structurally similar compounds, acted via different mechanisms to reduce body fat accumulation. MHB supplementation significantly reduced body weight gain, epididymal white adipose tissue weight, and plasma non-esterified free fatty acid levels in diet-induced obese mice. We also found that uncoupling protein 1 (UCP1) expression in brown adipose tissue (BAT) was significantly increased in MHB-fed mice at both the mRNA and protein levels. In addition, MHB administration in rats induced the β-adrenergic signaling cascade, which is related to cAMP accumulation in BAT, suggesting that MHB could modulate sympathetic nerve activity innervating BAT (BAT-SNA). Indeed, single oral administration of MHB elevated BAT-SNA in rats, and this elevation was dissipated by subdiaphragmatic vagotomy. Single oral administration of MHB maintained BAT temperature at a significantly higher level than in control rats. Taken together, these findings indicate that MHB ameliorates diet-induced body fat accumulation, at least partly, by enhancing thermogenesis in BAT via BAT-SNA activation. Our data suggests that MHB is a useful tool for developing functional foods or

  4. Matured Hop Bittering Components Induce Thermogenesis in Brown Adipose Tissue via Sympathetic Nerve Activity

    PubMed Central

    Morimoto-Kobayashi, Yumie; Ohara, Kazuaki; Takahashi, Chika; Kitao, Sayoko; Wang, Guanying; Taniguchi, Yoshimasa; Katayama, Mikio; Nagai, Katsuya

    2015-01-01

    Obesity is the principal symptom of metabolic syndrome, which refers to a group of risk factors that increase the likelihood of atherosclerosis. In recent decades there has been a sharp rise in the incidence of obesity throughout the developed world. Iso-α-acids, the bitter compounds derived from hops in beer, have been shown to prevent diet-induced obesity by increasing lipid oxidation in the liver and inhibition of lipid absorption from the intestine. Whereas the sharp bitterness induced by effective dose of iso-α-acids precludes their acceptance as a nutrient, matured hop bittering components (MHB) appear to be more agreeable. Therefore, we tested MHB for an effect on ameliorating diet-induced body fat accumulation in rodents. MHB ingestion had a beneficial effect but, compared to iso-α-acids and despite containing structurally similar compounds, acted via different mechanisms to reduce body fat accumulation. MHB supplementation significantly reduced body weight gain, epididymal white adipose tissue weight, and plasma non-esterified free fatty acid levels in diet-induced obese mice. We also found that uncoupling protein 1 (UCP1) expression in brown adipose tissue (BAT) was significantly increased in MHB-fed mice at both the mRNA and protein levels. In addition, MHB administration in rats induced the β-adrenergic signaling cascade, which is related to cAMP accumulation in BAT, suggesting that MHB could modulate sympathetic nerve activity innervating BAT (BAT-SNA). Indeed, single oral administration of MHB elevated BAT-SNA in rats, and this elevation was dissipated by subdiaphragmatic vagotomy. Single oral administration of MHB maintained BAT temperature at a significantly higher level than in control rats. Taken together, these findings indicate that MHB ameliorates diet-induced body fat accumulation, at least partly, by enhancing thermogenesis in BAT via BAT-SNA activation. Our data suggests that MHB is a useful tool for developing functional foods or

  5. New Insights into Enhancing Maximal Exercise Performance Through the Use of a Bitter Tastant.

    PubMed

    Gam, Sharon; Guelfi, Kym J; Fournier, Paul A

    2016-10-01

    It is generally acknowledged that for an orally administered ergogenic aid to enhance exercise performance it must first be absorbed by the gastrointestinal tract before exerting its effects. Recently, however, it has been reported that some ergogenic aids can affect exercise performance without prior absorption by the gastrointestinal tract. This is best illustrated by studies that have shown that rinsing the mouth with a carbohydrate (CHO) solution, without swallowing it, significantly improves exercise performance. The ergogenic effects of CHO mouth rinsing in these studies have been attributed to the activation of the brain by afferent taste signals, but the specific mechanisms by which this brain activation translates to enhanced exercise performance have not yet been elucidated. Given the benefits of CHO mouth rinsing for exercise performance, this raises the issue of whether other types of tastants, such as bitter-tasting solutions, may also improve exercise performance. Recently, we performed a series of studies investigating whether the bitter tastant quinine can improve maximal sprint performance in competitive male cyclists, and, if so, to examine some of the possible mechanisms whereby this effect may occur. These studies have shown that mouth rinsing and ingesting a bitter-tasting quinine solution can significantly improve the performance of a maximal cycling sprint. There is also evidence that the ergogenic effect of quinine is mediated, at least in part, by an increase in autonomic nervous system activation and/or corticomotor excitability. The purpose of this article is to discuss the results and implications of these recent studies and to suggest avenues for further research, which may add to the understanding of the way the brain integrates signals from the oral cavity with motor behaviour, as well as uncover novel strategies to improve exercise performance.

  6. Cholinergic chemosensory cells of the thymic medulla express the bitter receptor Tas2r131.

    PubMed

    Soultanova, Aichurek; Voigt, Anja; Chubanov, Vladimir; Gudermann, Thomas; Meyerhof, Wolfgang; Boehm, Ulrich; Kummer, Wolfgang

    2015-11-01

    The thymus is the site of T cell maturation which includes positive selection in the cortex and negative selection in the medulla. Acetylcholine is locally produced in the thymus and cholinergic signaling influences the T cell development. We recently described a distinct subset of medullary epithelial cells in the murine thymus which express the acetylcholine-synthesizing enzyme choline acetyltransferase (ChAT) and components of the canonical taste transduction cascade, i.e. transient receptor potential melastatin-like subtype 5 channel (TRPM5), phospholipase Cβ(2), and Gα-gustducin. Such a chemical phenotype is characteristic for chemosensory cells of mucosal surfaces which utilize bitter receptors for detection of potentially hazardous compounds and cholinergic signaling to initiate avoidance reflexes. We here demonstrate mRNA expression of bitter receptors Tas2r105, Tas2r108, and Tas2r131 in the murine thymus. Using a Tas2r131-tauGFP reporter mouse we localized the expression of this receptor to cholinergic cells expressing the downstream elements of the taste transduction pathway. These cells are distinct from the medullary thymic epithelial cells which promiscuously express tissue-restricted self-antigens during the process of negative selection, since double-labeling immunofluorescence showed no colocalization of autoimmune regulator (AIRE), the key mediator of negative selection, and TRPM5. These data demonstrate the presence of bitter taste-sensing signaling in cholinergic epithelial cells in the thymic medulla and opens a discussion as to what is the physiological role of this pathway.

  7. Efficacy of various techniques on biochemical characteristics and bitterness of pummelo juice.

    PubMed

    Kore, Vijaykumar T; Chakraborty, I

    2015-09-01

    The consumer acceptability of pummelo juice is affected badly due to the presence of bitter principles in it. Therefore in order to avoid such bitterness development, the extracted juice from pummelo was subjected to five different treatments like juice diffused into syrup (70°Brix), lye peeling of segments in boiling NaOH for 2-3 min, increasing the pH of juice, hot water treatment (50 °C) prior to peeling for 20 min and without any treatment (control) for suppressing the development of bitterness in the juice. Based on bio-chemical analysis, diffusion of juice into syrup (70°Brix) showed better result as compared to other treatments. The maximum amount of TSS was found in juice diffused into syrup (i. e. 45, 30 and 15°Brix) along with highest TSS/acid ratio (92.21, 49.87 and 17.53). Higher amount of acidity was observed in pH adjusted samples with 4.25, 4.50 and 4.75 respectively. However, control samples showed higher amount of ascorbic acid (73.97 mg/100 ml juice) content followed by pH adjusted samples. The highest organoleptic score for taste (8.00), colour (8.83), aroma (8.66), overall acceptability (7.88) and extent of debittering (7.50) were recorded in juice diffused into syrup 70°Brix and achieved final TSS of juice at 45, 30 and 15°Brix respectively. Moreover, the above treatment (juice diffused into syrup 70°Brix) showed promising low cost and easy to adopt technique of debittering in respect of extent of debittering and maintaining sensory quality during storage of pummel juice.

  8. Selection on the human bitter taste gene, TAS2R16, in Eurasian populations.

    PubMed

    Li, Hui; Pakstis, Andrew J; Kidd, Judith R; Kidd, Kenneth K

    2011-06-01

    Bitter taste is one of the most important senses alerting humans to noxious foods. In gatherer communities, sensitivity to bitterness is presumably advantageous because of various noxious plants. TAS2R16 is the gene coding the taste receptor molecules for some of the most common toxins in plants. A previous study of this gene indicated selection has increased the frequency of a derived allele in this gene that arose before the human expansion out of Africa. We have applied a different methodology for detecting selection, the Long Range Haplotype (LRH) analysis, to TAS2R16 in a larger sampling of populations from around the world. The haplotype with the derived alleles at both the functional polymorphism and a polymorphism in the regulatory region of TAS2R16 showed evidence for recent positive selection in most of the Eurasian populations, though the highest selection signal occurs in Mbuti Pygmies, an African hunter-gatherer group. In Eurasia, only populations of Mesopotamia and the southeast coast of China have no signals of selection. The evidence of recent selection found in most Eurasian populations differs from the geographic pattern seen in the earlier study of selection. One can speculate that the difference may result from a gathering lifestyle extending into the most recent 10,000 yrs and the need to recognize newly encountered bitter natural toxins as populations expanded into new environments and the biota changes with the ending of the most recent ice age. Alternatively, the promoter region variant may be a marker for altered function beyond what the derived amino acid allele conferred. PMID:21740153

  9. Cholinergic chemosensory cells of the thymic medulla express the bitter receptor Tas2r131.

    PubMed

    Soultanova, Aichurek; Voigt, Anja; Chubanov, Vladimir; Gudermann, Thomas; Meyerhof, Wolfgang; Boehm, Ulrich; Kummer, Wolfgang

    2015-11-01

    The thymus is the site of T cell maturation which includes positive selection in the cortex and negative selection in the medulla. Acetylcholine is locally produced in the thymus and cholinergic signaling influences the T cell development. We recently described a distinct subset of medullary epithelial cells in the murine thymus which express the acetylcholine-synthesizing enzyme choline acetyltransferase (ChAT) and components of the canonical taste transduction cascade, i.e. transient receptor potential melastatin-like subtype 5 channel (TRPM5), phospholipase Cβ(2), and Gα-gustducin. Such a chemical phenotype is characteristic for chemosensory cells of mucosal surfaces which utilize bitter receptors for detection of potentially hazardous compounds and cholinergic signaling to initiate avoidance reflexes. We here demonstrate mRNA expression of bitter receptors Tas2r105, Tas2r108, and Tas2r131 in the murine thymus. Using a Tas2r131-tauGFP reporter mouse we localized the expression of this receptor to cholinergic cells expressing the downstream elements of the taste transduction pathway. These cells are distinct from the medullary thymic epithelial cells which promiscuously express tissue-restricted self-antigens during the process of negative selection, since double-labeling immunofluorescence showed no colocalization of autoimmune regulator (AIRE), the key mediator of negative selection, and TRPM5. These data demonstrate the presence of bitter taste-sensing signaling in cholinergic epithelial cells in the thymic medulla and opens a discussion as to what is the physiological role of this pathway. PMID:26102274

  10. Sweet and bitter taste: structure and conformations of two aspartame dipeptide analogues.

    PubMed

    Benedetti, E; Gavuzzo, E; Santini, A; Kent, D R; Zhu, Y F; Zhu, Q; Mahr, C; Goodman, M

    1995-01-01

    The synthesis and X-ray diffraction analysis of two dipeptide taste ligands have been carried out as part of our study of the molecular basis of taste. The compounds L-aspartyl-D-alpha-methylphenylalanine methyl ester [L-Asp-D-(alpha Me)Phe-OMe] and L-aspartyl-D-alanyl-2,2,5, 5-tetramethylcyclopentanyl ester [L-Asp-D-Ala-OTMCP] elicit bitter and sweet taste, respectively. The C-terminal residues of the two analogues adopt distinctly different conformations in the solid state. The aspartyl moiety assumes the same conformation found in other dipeptide taste ligands with the side-chain carboxylate and the amino groups forming a zwitterionic ring with a conformation defined by psi, chi 1 = 157.7 degrees, -61.5 degrees for L-Asp-D-Ala-OTMCP and 151.0 degrees, -68.8 degrees for L-Asp-D-(alpha Me)Phe-OMe. In the second residue, a left-handed helical conformation is observed for the (alpha Me)Phe residue of L-Asp-D-(alpha Me)Phe-OMe with phi 2 = 49.0 degrees and psi 2 = 47.9 degrees, while the Ala residue of L-Asp-D-Ala-OTMCP adopts a semi-extended conformation characterized by dihedral angles phi 2 = 62.8 degrees and psi 2 = -139.9 degrees. The solid-state structure of the bitter L-Asp-D-(alpha Me)Phe-OMe is extended: while the crystal structure of the sweet L-Asp-D-OTMCP roughly adopts the typical L-shaped structure shown by other sweeteners. The data of L-Asp-D-(alpha Me)Phe-OMe are compared with those of its diastereoisomer L-Asp-L-(alpha Me)Phe-OMe. Conformational analysis of the two taste ligands in solution by NMR and computer simulations agrees well with our model for sweet and bitter tastes.

  11. Hydrogeologic framework of the North Carolina Coastal Plain aquifer system

    USGS Publications Warehouse

    Winner, M.D.; Coble, R.W.

    1989-01-01

    The hydrogeologic framework of the North Carolina Coastal Plain aquifer system consists of ten aquifers separated by nine confining units. From top to bottom the aquifers are: the surficial aquifer, Yorktown aquifer, Pungo River aquifer, Castle Hayne aquifer, Beaufort aquifer, Peedee aquifer, Black Creek aquifer, upper Cape Fear aquifer, lower Cape Fear aquifer, and the Lower Cretaceous aquifer. The uppermost aquifer (the surficial aquifer in most places) is a water-table aquifer and the bottom of the system is underlain by crystalline bedrock. The sedimentary deposits forming the aquifers are of Holocene to Cretaceous age and are composed mostly of sand with lesser amounts of gravel and limestone. Confining units between aquifers are composed primarily of clay and silt. The thickness of the aquifers ranges from zero along the Fall Line to more than 10,000 feet at Cape Hatteras. Prominent structural features are the increasing easterly homoclinal dip of the sediments and the Cape Fear arch, the axis of which trends in a southeast direction. The stratigraphic continuity is determined from correlations of 161 geophysical logs along with data from drillers' and geologists' logs. Aquifers were defined by means of these logs plus water-level and water-quality data and evidence of the continuity of pumping effects. Eighteen hydrogeologic sections depict the correlation of these aquifers throughout the Coastal Plain.

  12. Synergistic effects of sour taste and low temperature in suppressing the bitterness of Aminoleban® EN.

    PubMed

    Haraguchi, Tamami; Yoshida, Miyako; Hazekawa, Mai; Uchida, Takahiro

    2011-01-01

    Aminoleban® EN, a nutritional product for patients with liver failure, contains three branched-chain amino acids (BCAAs): L-leucine, L-isoleucine, and L-valine. As BCAAs are extremely bitter, Aminoleban® EN has a low palatability, which is a major cause of patient noncompliance. Nutrients for liver failure often need to be taken for long periods, and poor medication compliance can cause serious problems, such as encephalopathy. Therefore it is important to suppress the bitter taste of Aminoleban® EN and thereby improve patient compliance. There are already six different flavoured powders (coffee, green-tea, apple, fruit, plum and pineapple) which can be added to Aminoleban® EN to reduce its unpleasant taste and smell, but it is possible that other factors, such as temperature, may also improve the palatability of Aminoleban® EN. In this study, flavours alone significantly decreased the bitterness intensity of Aminoleban® EN. It was thought that the sweetness and sourness of the flavoured powder would be the main factors involved in decreasing the bitterness. However, low temperature (0-5 °C) decreased the bitterness intensity of Aminoleban® EN, with or without the flavoured powders, compared with normal room temperature (25-30 °C). The sourness intensity of flavoured powders was not decreased at low temperatures, but the sweetness intensity of some flavoured powders did decrease. These results suggest that sourness can be tasted even at low temperatures. As not only the addition of flavoured powders but also low temperatures can reduce the bitterness of Aminioleban® EN, the combination of a sour-flavoured powder and a low temperature will improve the palatability of Aminoleban® EN the most.

  13. Dextromethorphan Mediated Bitter Taste Receptor Activation in the Pulmonary Circuit Causes Vasoconstriction

    PubMed Central

    Upadhyaya, Jasbir D.; Chakraborty, Raja; Pydi, Sai P.; Bhullar, Rajinder P.; Dakshinamurti, Shyamala; Chelikani, Prashen

    2014-01-01

    Activation of bitter taste receptors (T2Rs) in human airway smooth muscle cells leads to muscle relaxation and bronchodilation. This finding led to our hypothesis that T2Rs are expressed in human pulmonary artery smooth muscle cells and might be involved in regulating the vascular tone. RT-PCR was performed to reveal the expression of T2Rs in human pulmonary artery smooth muscle cells. Of the 25 T2Rs, 21 were expressed in these cells. Functional characterization was done by calcium imaging after stimulating the cells with different bitter agonists. Increased calcium responses were observed with most of the agonists, the largest increase seen for dextromethorphan. Previously in site-directed mutational studies, we have characterized the response of T2R1 to dextromethorphan, therefore, T2R1 was selected for further analysis in this study. Knockdown with T2R1 specific shRNA decreased mRNA levels, protein levels and dextromethorphan-induced calcium responses in pulmonary artery smooth muscle cells by up to 50%. To analyze if T2Rs are involved in regulating the pulmonary vascular tone, ex vivo studies using pulmonary arterial and airway rings were pursued. Myographic studies using porcine pulmonary arterial and airway rings showed that stimulation with dextromethorphan led to contraction of the pulmonary arterial and relaxation of the airway rings. This study shows that dextromethorphan, acting through T2R1, causes vasoconstrictor responses in the pulmonary circuit and relaxation in the airways. PMID:25340739

  14. Using milk fat to reduce the irritation and bitter taste of ibuprofen

    PubMed Central

    Bennett, Samantha M.; Zhou, Lisa; Hayes, John E.

    2012-01-01

    Bitterness and irritation elicited by pharmaceutically active molecules remain problematic for pediatric medications, fortified foods and dietary supplements. Few effective methods exist for reducing these unpalatable sensations, negatively impacting medication compliance and intake of beneficial phytonutrients. A physicochemical approach to masking these sensations may be the most successful approach for generalizability to a wide range of structurally and functionally unique compounds. Here, solutions of the non-steroidal anti- inflammatory drug, ibuprofen, were prepared in milk products with varying fat content. Our hypothesis, based on other reports of similar phenomena, was that increasing the fat content would cause ibuprofen to selectively partition into the fat phase, thereby reducing interaction with sensory receptors and decreasing adversive sensations. Quantification of the aqueous concentration of ibuprofen was performed using an isocratic HPLC method coupled with an external standard curve. Sensory testing showed a modest but significant decrease (~20%) in irritation ratings between the skim milk (0% fat) and the half-and-half (11% fat) samples, indicating that increased fat may contribute to a reduced sensory response. Bitterness was not reduced, remaining constant over all fat levels. The HPLC results indicate a constant amount of ibuprofen remained in the aqueous phase regardless of fat level, so a simple partitioning hypothesis cannot explain the reduced irritancy ratings. Association of ionized ibuprofen with continuous phase solutes such as unabsorbed protein should be explored in future work. PMID:23527314

  15. A Subset of Mouse Colonic Goblet Cells Expresses the Bitter Taste Receptor Tas2r131

    PubMed Central

    Prandi, Simone; Bromke, Marta; Hübner, Sandra; Voigt, Anja; Boehm, Ulrich; Meyerhof, Wolfgang; Behrens, Maik

    2013-01-01

    The concept that gut nutrient sensing involves taste receptors has been fueled by recent reports associating the expression of taste receptors and taste-associated signaling molecules in the gut and in gut-derived cell lines with physiological responses induced by known taste stimuli. However, for bitter taste receptors (Tas2rs), direct evidence for their functional role in gut physiology is scarce and their cellular expression pattern remained unknown. We therefore investigated Tas2r expression in mice. RT-PCR experiments assessed the presence of mRNA for Tas2rs and taste signaling molecules in the gut. A gene-targeted mouse strain was established to visualize and identify cell types expressing the bitter receptor Tas2r131. Messenger RNA for various Tas2rs and taste signaling molecules were detected by RT-PCR in the gut. Using our knock-in mouse strain we demonstrate that a subset of colonic goblet cells express Tas2r131. Cells that express this receptor are absent in the upper gut and do not correspond to enteroendocrine and brush cells. Expression in colonic goblet cells is consistent with a role of Tas2rs in defense mechanisms against potentially harmful xenobiotics. PMID:24367558

  16. Fluorescence-based optimization of human bitter taste receptor expression in Saccharomyces cerevisiae

    SciTech Connect

    Sugawara, Taishi; Ito, Keisuke; Shiroishi, Mitsunori; Tokuda, Natsuko; Asada, Hidetsugu; Yurugi-Kobayashi, Takami; Shimamura, Tatsuro; Misaka, Takumi; Nomura, Norimichi; Murata, Takeshi; Abe, Keiko; Iwata, So; and others

    2009-05-15

    Human TAS2 receptors (hTAS2Rs) perceive bitter tastants, but few studies have explored the structure-function relationships of these receptors. In this paper, we report our trials on the large-scale preparations of hTAS2Rs for structural analysis. Twenty-five hTAS2Rs were expressed using a GFP-fusion yeast system in which the constructs and the culture conditions (e.g., the signal sequence, incubation time and temperature after induction) were optimized by measuring GFP fluorescence. After optimization, five hTAS2Rs (hTAS2R7, hTAS2R8, hTAS2R16, hTAS2R41, and hTAS2R48) were expressed at levels greater than 1 mg protein/L of culture, which is a preferable level for purification and crystallization. Among these five bitter taste receptors, hTAS2R41 exhibited the highest detergent solubilization efficiency of 87.1% in n-dodecyl-{beta}-D-maltopyranoside (DDM)/cholesteryl hemisuccinate (CHS). Fluorescence size-exclusion chromatography showed that hTAS2R41 exhibited monodispersity in DDM/CHS without aggregates, suggesting that hTAS2R41 is a good target for future crystallization trials.

  17. Bitter triggers acetylcholine release from polymodal urethral chemosensory cells and bladder reflexes.

    PubMed

    Deckmann, Klaus; Filipski, Katharina; Krasteva-Christ, Gabriela; Fronius, Martin; Althaus, Mike; Rafiq, Amir; Papadakis, Tamara; Renno, Liane; Jurastow, Innokentij; Wessels, Lars; Wolff, Miriam; Schütz, Burkhard; Weihe, Eberhard; Chubanov, Vladimir; Gudermann, Thomas; Klein, Jochen; Bschleipfer, Thomas; Kummer, Wolfgang

    2014-06-01

    Chemosensory cells in the mucosal surface of the respiratory tract ("brush cells") use the canonical taste transduction cascade to detect potentially hazardous content and trigger local protective and aversive respiratory reflexes on stimulation. So far, the urogenital tract has been considered to lack this cell type. Here we report the presence of a previously unidentified cholinergic, polymodal chemosensory cell in the mammalian urethra, the potential portal of entry for bacteria and harmful substances into the urogenital system, but not in further centrally located parts of the urinary tract, such as the bladder, ureter, and renal pelvis. Urethral brush cells express bitter and umami taste receptors and downstream components of the taste transduction cascade; respond to stimulation with bitter (denatonium), umami (monosodium glutamate), and uropathogenic Escherichia coli; and release acetylcholine to communicate with other cells. They are approached by sensory nerve fibers expressing nicotinic acetylcholine receptors, and intraurethral application of denatonium reflexively increases activity of the bladder detrusor muscle in anesthetized rats. We propose a concept of urinary bladder control involving a previously unidentified cholinergic chemosensory cell monitoring the chemical composition of the urethral luminal microenvironment for potential hazardous content. PMID:24843119

  18. Impact of Prior Consumption on Sour, Sweet, Salty, and Bitter Tastes.

    PubMed

    Christina, Josephine; Palma-Salgado, Sindy; Clark, Diana; Kahraman, Ozan; Lee, Soo-Yeun

    2016-02-01

    Food sensory tests generally require panelists to abstain from food or beverage consumption 30 min to an hour before a tasting session. However, investigators do not have a complete control over panelists' intentional or unintentional consumption prior to a tasting session. Currently, it is unclear how prior consumption impacts the results of the tasting session. The aim of this study was to determine the effects of temporary and lingering mouth irritation caused by the consumption of coffee, orange juice, and gum within 1, 15, or 30 min prior to the tasting session on the perception of 4 basic tastes: sweet, salty, sour, and bitter. Fifty-two panelists were served a beverage (orange juice, coffee, and water) or were asked to chew a piece of gum, and then, remained in the waiting room for 1, 15, or 30 min. They were then asked to report taste intensities using 15-cm unstructured line scales. Mean intensities of all tastes were not significantly different when orange juice was a primer at 1, 15, and 30 min when compared to water. Mean intensities of bitter were significantly lower when coffee was a primer at 1, 15, and 30 min than when water was a primer. Mean intensities of sweet were significantly lower when gum was a primer at 1 and 15 min than when water was a primer. The findings showed that it is necessary for 30 min or more waiting period of no food or beverage consumption prior to sensory testing. PMID:26709855

  19. Impact of Prior Consumption on Sour, Sweet, Salty, and Bitter Tastes.

    PubMed

    Christina, Josephine; Palma-Salgado, Sindy; Clark, Diana; Kahraman, Ozan; Lee, Soo-Yeun

    2016-02-01

    Food sensory tests generally require panelists to abstain from food or beverage consumption 30 min to an hour before a tasting session. However, investigators do not have a complete control over panelists' intentional or unintentional consumption prior to a tasting session. Currently, it is unclear how prior consumption impacts the results of the tasting session. The aim of this study was to determine the effects of temporary and lingering mouth irritation caused by the consumption of coffee, orange juice, and gum within 1, 15, or 30 min prior to the tasting session on the perception of 4 basic tastes: sweet, salty, sour, and bitter. Fifty-two panelists were served a beverage (orange juice, coffee, and water) or were asked to chew a piece of gum, and then, remained in the waiting room for 1, 15, or 30 min. They were then asked to report taste intensities using 15-cm unstructured line scales. Mean intensities of all tastes were not significantly different when orange juice was a primer at 1, 15, and 30 min when compared to water. Mean intensities of bitter were significantly lower when coffee was a primer at 1, 15, and 30 min than when water was a primer. Mean intensities of sweet were significantly lower when gum was a primer at 1 and 15 min than when water was a primer. The findings showed that it is necessary for 30 min or more waiting period of no food or beverage consumption prior to sensory testing.

  20. Development of Bitter Taste Sensor Using Ionic-Liquid/Polymer Membranes

    NASA Astrophysics Data System (ADS)

    Akutagawa, Nobuyuki; Toida, Jinichi; Amano, Yoshihiko; Ikezaki, Hidekazu; Toko, Kiyoshi; Arikawa, Yukihiko

    A taste sensor is composed of several kinds of lipid/polymer membranes as transducers which convert taste information to electric signal. Thus, the role of membranes is very important to detect various taste components. In this paper, we developed novel membranes which specifically respond to quinine that is typical bitter substances. These membranes were composed of hydrophobic ionic liquid such as N, N, N-trimethyl-N-propylammonium bis(trifluoromethansulfonyl)imide, 1-butyl-3-methylimidazolium hexafluorophosphate and 1-butylpyridinium hexafluorophosphate, a plasticizer, 2-nitrophenyl octyl ether and a polymer, polyvinyl chloride. In addition to quinine, they also showed response to both several kinds of alkaloids such as caffeine and strychnine, and non-alkaloid such as phenylthiocarbamide. The order of these responses was equal to that of the tongue glossopharyngeal nerve of flog. Furthermore, there were the other alkaloids which response to these membranes. Especially in these alkaloids, they showed high response to denatonium benzoate and berberin chloride which have a strong bitter taste.

  1. Antidiabetic effects of Momordica charantia (bitter melon) and its medicinal potency

    PubMed Central

    Joseph, Baby; Jini, D

    2013-01-01

    Diabetes mellitus is among the most common disorder in developed and developing countries, and the disease is increasing rapidly in most parts of the world. It has been estimated that up to one-third of patients with diabetes mellitus use some form of complementary and alternative medicine. One plant that has received the most attention for its anti-diabetic properties is bitter melon, Momordica charantia (M. charantia), commonly referred to as bitter gourd, karela and balsam pear. Its fruit is also used for the treatment of diabetes and related conditions amongst the indigenous populations of Asia, South America, India and East Africa. Abundant pre-clinical studies have documented in the anti-diabetic and hypoglycaemic effects of M. charantia through various postulated mechanisms. However, clinical trial data with human subjects are limited and flawed by poor study design and low statistical power. The present review is an attempt to highlight the antidiabetic activity as well as phytochemical and pharmacological reports on M. charantia and calls for better-designed clinical trials to further elucidate its possible therapeutic effects on diabetes.

  2. Simultaneous determination of prenylflavonoid and hop bitter acid in beer lee by HPLC-DAD-MS.

    PubMed

    Kao, T H; Wu, G Y

    2013-11-15

    An HPLC-DAD-MS method with high accuracy and precision was developed for determination of prenylflavonoids and hop bitter acids in beer lee, a by-product from beer brewing process. Four prenylflavonoids and nine hop bitter acids can be simultaneously separated in 29 min using a Thermo HyPURITY C18 column in combination with diode array dectector and mass spectrometer with HPLC solvent gradient system of phosphoric acid aqueous solution at pH 1.6 and acetonitrile at a flow rate of 1.5 mL/min and detection wavelength at 314 nm. Beer lee is found to contain isoxanthohumol (36.2 μg/g), xanthohumol (29.6 μg/g), 8-prenylnaringenin (7.84 μg/g), 6-prenylnaringenin (19.2 μg/g), cohumulone (44.7 μg/g), humulone (123 μg/g), adhumulone (21.8 μg/g), colupulone (44.2 μg/g), lupulone (33.2 μg/g), and adlupulone (5.76 μg/g).

  3. Prototype of 10 Tesla Water Cooled Bitter-type Magnet System

    NASA Astrophysics Data System (ADS)

    Bates, E. M.; Birmingham, W. J.; Riverva, W. F.; Romero-Talamas, C. A.

    2015-11-01

    A 1 Tesla water cooled Bitter-type magnetic system has been designed and is under construction at the Dusty Plasma Laboratory of the University of Maryland, Baltimore County (UMBC). It is a scaled version of a 10 T Bitter-type magnet that will be used in dusty plasma experiments where dust larger than 500 nm diameter will be strongly magnetized. We present here the design methods used for both magnets, and discuss the design parameters that drive the magnet cooling and power storage bank subsystems. The pressure vessel and plasma vacuum chamber subsystems are then built with the aforementioned subsystems as constraints. To validate our design, magnetic field and temperature measurements within the prototype magnet are compared to finite element analysis (FEA) and analytical methods used for preliminary designing. This knowledge will be used to finalize the 10 T magnet design. Once operational, the 10 T magnet will be programmable to be on for at least ten seconds to several minutes, with up to 20 plasma events planned per day.

  4. Bitter triggers acetylcholine release from polymodal urethral chemosensory cells and bladder reflexes.

    PubMed

    Deckmann, Klaus; Filipski, Katharina; Krasteva-Christ, Gabriela; Fronius, Martin; Althaus, Mike; Rafiq, Amir; Papadakis, Tamara; Renno, Liane; Jurastow, Innokentij; Wessels, Lars; Wolff, Miriam; Schütz, Burkhard; Weihe, Eberhard; Chubanov, Vladimir; Gudermann, Thomas; Klein, Jochen; Bschleipfer, Thomas; Kummer, Wolfgang

    2014-06-01

    Chemosensory cells in the mucosal surface of the respiratory tract ("brush cells") use the canonical taste transduction cascade to detect potentially hazardous content and trigger local protective and aversive respiratory reflexes on stimulation. So far, the urogenital tract has been considered to lack this cell type. Here we report the presence of a previously unidentified cholinergic, polymodal chemosensory cell in the mammalian urethra, the potential portal of entry for bacteria and harmful substances into the urogenital system, but not in further centrally located parts of the urinary tract, such as the bladder, ureter, and renal pelvis. Urethral brush cells express bitter and umami taste receptors and downstream components of the taste transduction cascade; respond to stimulation with bitter (denatonium), umami (monosodium glutamate), and uropathogenic Escherichia coli; and release acetylcholine to communicate with other cells. They are approached by sensory nerve fibers expressing nicotinic acetylcholine receptors, and intraurethral application of denatonium reflexively increases activity of the bladder detrusor muscle in anesthetized rats. We propose a concept of urinary bladder control involving a previously unidentified cholinergic chemosensory cell monitoring the chemical composition of the urethral luminal microenvironment for potential hazardous content.

  5. Isolation of bitter acids from hops (Humulus lupulus L.) using countercurrent chromatography.

    PubMed

    Dahlberg, Clinton J; Harris, Guy; Urban, Jan; Tripp, Matthew L; Bland, Jeffrey S; Carroll, Brian J

    2012-05-01

    Commercially available hops (Humulus lupulus L.) bitter acid extracts contain a mixture of three major congeners (co-, n-, and ad-) in addition to cis/trans diastereomers for each congener. Individual isomerized α-acids were obtained by the consecutive application of two separate countercurrent chromatography methods. First, individual isomerized α-acid congeners as a mixture of cis/trans diastereomers were obtained using a solvent system consisting of hexane and aqueous buffer. The second purification, capable of separating cis/trans diastereomers, was accomplished using a quaternary solvent system; an alternative procedure using β-cyclodextrin followed by countercurrent chromatography was also investigated. The NaBH(4) reduction of the purified isomerized α-acid compounds followed by countercurrent chromatography purification resulted in individual ρ iso α-acids (>95%). Similarly, catalytic hydrogenation of the purified isomerized α-acid compounds followed by countercurrent chromatography purification produced individual tetrahydro isomerized α-acids (>95%). Reported herein is a widely applicable approach that focuses on three critical variables--solvent system composition, pH, and buffer-to-sample ratio--that enable the efficient purification of individual bitter acids (≥95%) from commercially available hops extracts.

  6. Dextromethorphan mediated bitter taste receptor activation in the pulmonary circuit causes vasoconstriction.

    PubMed

    Upadhyaya, Jasbir D; Singh, Nisha; Sikarwar, Anurag S; Chakraborty, Raja; Pydi, Sai P; Bhullar, Rajinder P; Dakshinamurti, Shyamala; Chelikani, Prashen

    2014-01-01

    Activation of bitter taste receptors (T2Rs) in human airway smooth muscle cells leads to muscle relaxation and bronchodilation. This finding led to our hypothesis that T2Rs are expressed in human pulmonary artery smooth muscle cells and might be involved in regulating the vascular tone. RT-PCR was performed to reveal the expression of T2Rs in human pulmonary artery smooth muscle cells. Of the 25 T2Rs, 21 were expressed in these cells. Functional characterization was done by calcium imaging after stimulating the cells with different bitter agonists. Increased calcium responses were observed with most of the agonists, the largest increase seen for dextromethorphan. Previously in site-directed mutational studies, we have characterized the response of T2R1 to dextromethorphan, therefore, T2R1 was selected for further analysis in this study. Knockdown with T2R1 specific shRNA decreased mRNA levels, protein levels and dextromethorphan-induced calcium responses in pulmonary artery smooth muscle cells by up to 50%. To analyze if T2Rs are involved in regulating the pulmonary vascular tone, ex vivo studies using pulmonary arterial and airway rings were pursued. Myographic studies using porcine pulmonary arterial and airway rings showed that stimulation with dextromethorphan led to contraction of the pulmonary arterial and relaxation of the airway rings. This study shows that dextromethorphan, acting through T2R1, causes vasoconstrictor responses in the pulmonary circuit and relaxation in the airways. PMID:25340739

  7. In vitro evaluation of potential bitterness-masking terpenoids from the Canada goldenrod (Solidago canadensis).

    PubMed

    Li, Jie; Pan, Li; Fletcher, Joshua N; Lv, Wei; Deng, Ye; Vincent, Michael A; Slack, Jay P; McCluskey, T Scott; Jia, Zhonghua; Cushman, Mark; Kinghorn, A Douglas

    2014-07-25

    In a screening of extracts of selected plants native to Ohio against the human bitterness receptor hTAS2R31, a chloroform-soluble extract of the aerial parts of Solidago canadensis (Canada goldenrod) was determined to have hTAS2R31 antagonistic activity and, thus, was fractionated for isolation of potential bitterness-masking agents. One new labdane diterpenoid, solidagol (1), and six known terpenoids, including two labdane diterpenoids (2 and 3), three clerodane diterpenoids (6β-angeloyloxykolavenic acid, 6β-tigloyloxykolavenic acid, and crotonic acid), and a triterpenoid (longispinogenin), were isolated. Among these compounds, 3β-acetoxycopalic acid (2) was found to be the first member of the labdane diterpene class shown to have inhibitory activity against hTAS2R31 activation (IC50 8 μM). A homology model of hTAS2R31 was constructed, and the molecular docking of 2 to this model indicated that this diterpenoid binds well to the active site of hTAS2R31, whereas this was not the case for the closely structurally related compound 3 (sempervirenic acid). The content of 2 in the chloroform-soluble portion of the methanolic extract of S. canadensis was up to 2.24 g/100 g dry weight, as determined by HPLC. PMID:24999828

  8. Receptors for bitter, sweet and umami taste couple to inhibitory G protein signaling pathways.

    PubMed

    Ozeck, Mark; Brust, Paul; Xu, Hong; Servant, Guy

    2004-04-12

    Taste receptors are thought to couple to the G protein Galpha-gustducin to initiate signal transduction cascades leading to taste perception. To further characterize the G protein-coupling selectivity of these receptors, we expressed them in HEK293 cells and monitored the modulation of different signaling pathways upon stimulation. We found that the bitter compound cycloheximide induces phosphorylation of extracellular signal-regulated kinases1 and 2 (ERK 1/2) and inhibits cAMP accumulation in HEK293 cells expressing the mouse bitter T2R(5) receptor. These effects are totally abolished upon treatment with pertussis toxin. On the other hand, sweeteners and monosodium glutamate induce phosphorylation of ERK1/2 and inhibit cAMP accumulation in HEK293 cells expressing the human sweet T1R(2)/T1R(3) receptor and the human umami T1R(1)/T1R(3) receptor, respectively. The effects of these taste modalities are also prevented by treatment with pertussis toxin. Collectively, our results show that taste receptors can functionally couple to Galpha(i/o) proteins to transmit intracellular signals.

  9. 40 CFR 149.3 - Critical Aquifer Protection Areas.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 24 2012-07-01 2012-07-01 false Critical Aquifer Protection Areas. 149... (CONTINUED) SOLE SOURCE AQUIFERS Criteria for Identifying Critical Aquifer Protection Areas § 149.3 Critical Aquifer Protection Areas. A Critical Aquifer Protection Area is either: (a) All or part of an area...

  10. 40 CFR 149.3 - Critical Aquifer Protection Areas.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 24 2013-07-01 2013-07-01 false Critical Aquifer Protection Areas. 149... (CONTINUED) SOLE SOURCE AQUIFERS Criteria for Identifying Critical Aquifer Protection Areas § 149.3 Critical Aquifer Protection Areas. A Critical Aquifer Protection Area is either: (a) All or part of an area...

  11. 40 CFR 149.3 - Critical Aquifer Protection Areas.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 23 2014-07-01 2014-07-01 false Critical Aquifer Protection Areas. 149... (CONTINUED) SOLE SOURCE AQUIFERS Criteria for Identifying Critical Aquifer Protection Areas § 149.3 Critical Aquifer Protection Areas. A Critical Aquifer Protection Area is either: (a) All or part of an area...

  12. Capture zones for simple aquifers

    USGS Publications Warehouse

    McElwee, Carl D.

    1991-01-01

    Capture zones showing the area influenced by a well within a certain time are useful for both aquifer protection and cleanup. If hydrodynamic dispersion is neglected, a deterministic curve defines the capture zone. Analytical expressions for the capture zones can be derived for simple aquifers. However, the capture zone equations are transcendental and cannot be explicitly solved for the coordinates of the capture zone boundary. Fortunately, an iterative scheme allows the solution to proceed quickly and efficiently even on a modest personal computer. Three forms of the analytical solution must be used in an iterative scheme to cover the entire region of interest, after the extreme values of the x coordinate are determined by an iterative solution. The resulting solution is a discrete one, and usually 100-1000 intervals along the x-axis are necessary for a smooth definition of the capture zone. The presented program is written in FORTRAN and has been used in a variety of computing environments. No graphics capability is included with the program; it is assumed the user has access to a commercial package. The superposition of capture zones for multiple wells is expected to be satisfactory if the spacing is not too close. Because this program deals with simple aquifers, the results rarely will be the final word in a real application.

  13. The Tuscaloosa Aquifer system in Mississippi

    USGS Publications Warehouse

    Boswell, E.H.

    1978-01-01

    A three-sheet map report describes the Tuscaloosa aquifer system in Mississippi. The Tuscaloosa aquifer system, of Cretaceous age , is in the interconnected irregular sand and gravel beds in the Coker and Gordo Formations. The aquifer contains freshwater in an area of about 9,000 sq mi in northeastern Mississippi. Water produced from the aquifer by about 90 water systems and numerous industries in 1975 averaged about 47 Mgal/d. Regional water level declines have averaged less than two feet per year and the aquifer has a large potential for future development. The aquifer is used in some areas where the dissolved-solids concentration is more than 500 mg/L and where wells exceed 2,000 ft in depth. The most common problems in water supplies are excessive chloride and iron. (Woodard-USGS)

  14. The effect of various substances on the suppression of the bitterness of quinine-human gustatory sensation, binding, and taste sensor studies.

    PubMed

    Nakamura, Tomoko; Tanigake, Atsu; Miyanaga, Yohko; Ogawa, Tazuko; Akiyoshi, Takeshi; Matsuyama, Kenji; Uchida, Takahiro

    2002-12-01

    The purpose of this study was to quantify the degree of suppression of the perceived bitterness of quinine by various substances and to examine the mechanism of bitterness suppression. The following compounds were tested for their ability to suppress bitterness: sucrose, a natural sweetener; aspartame, a noncaloric sweetener; sodium chloride (NaCl) as the electrolyte; phosphatidic acid, a commercial bitterness suppression agent; and tannic acid, a component of green tea. These substances were examined in a gustatory sensation test in human volunteers, a binding study, and using an artificial taste sensor. Sucrose, aspartame, and NaCl were effective in suppressing bitterness, although at comparatively high concentrations. An almost 80% inhibition of bitterness (calculated as concentration %) of a 0.1 mM quinine hydrochloride solution required 800 mM of sucrose, 8 mM of aspartame, and 300 mM NaCl. Similar levels of bitterness inhibition by phosphatidic acid and tannic acid (81.7, 61.0%, respectively) were obtained at much lower concentrations (1.0 (w/v)% for phosphatidic acid and 0.05 (w/v)% for tannic acid). The mechanism of the bitterness-depressing effect of phosphatidic acid and tannic acid was investigated in terms of adsorption and masking at the receptor site. With phosphatidic acid, 36.1% of the bitterness-depressing effect was found to be due to adsorption, while 45.6% was due to suppression at the receptor site. In the case of 0.05 (w/v)% tannic acid, the total bitterness-masking effect was 61.0%. The contribution of the adsorption effect was about 27.5% while the residual masking effect at the receptor site was almost 33%. Further addition of tannic acid (0.15 (w/v)%), however, increased the bitterness score of quinine, which probably represents an effect of the astringency of tannic acid itself. Finally, an artificial taste sensor was used to evaluate or predict the bitterness-depressing effect. The sensor output profile was shown to reflect the

  15. Identification of anthropogenic and natural inputs of sulfate and chloride into the karstic ground water of Guiyang, SW China: combined delta37Cl and delta34S approach.

    PubMed

    Liu, Cong-Qiang; Lang, Yun-Chao; Satake, Hiroshi; Wu, Jiahong; Li, Si-Liang

    2008-08-01

    Because of active exchange between surface and groundwater of a karstic hydrological system, the groundwater of Guiyang, the capital city of Guizhou Province, southwest China, has been seriously polluted by anthropogenic inputs of NO3-, SO4(2-), Cl-, and Na+. In this work, delta37Cl of chloride and delta34S variations of sulfate in the karstic surface/groundwater system were studied, with a main focus to identify contaminant sources, including their origins. The surface, ground, rain, and sewage water studied showed variable delta37Cl and delta34S values, in the range of -4.1 to +2.0 per thousand, and -20.4 to +20.9 per thousand for delta37Cl and delta34S (SO4(2-)), respectively. The rainwater samples yielded the lowest delta37Cl values among those observed to date for aerosols and rainwater. Chloride in the Guiyang area rain waters emanated from anthropogenic sources rather than being of marine origin, probably derived from HCl (g) emitted by coal combustion. By plotting 1/SO4(2-) vs delta34S and 1/Cl- vs delta37Cl, respectively, we were able to identify some clusters of data, which were assigned as atmospheric deposition (acid rain component), discharge from municipal sewage, paleo-brine components in clastic sedimentary rocks, dissolution of gypsum mainly in dolomite, oxidation of sulfide minerals in coal-containing clastic rocks, and possibly degradation of chlorine-containing organic matter. We conclude that human activities give a significant input of sulfate and chloride ions, as well as other contaminants, into the studied groundwater system through enhanced atmospheric deposition and municipal sewage, and that multiple isotopic tracers constitute a powerful tool to ascertain geochemical characteristics and origin of complex contaminants in groundwater.

  16. Bitter Orange

    MedlinePlus

    65998 ... https://nccih.nih.gov/health/bitterorange ... us ... 65998 ... https://nccih.nih.gov/health/bitterorange ... Herbal Medicine ... Herbal Medicine/Specifics ... us ... 65998 ... https://nccih. ...

  17. Sole Source Aquifer designation: petitioner guidance

    SciTech Connect

    Braem, L.

    1987-02-01

    The purpose of the guidance is to aid potential Sole Source Aquifer (SSA) petitioners to prepare and submit Sole Source Aquifer designation petitions to the Environmental Protection Agency. The Sole Source Aquifer program was established under the 1974 Safe Drinking Water Act, to protect principal or sole sources of drinking water for an area from contamination. The guidance presents an overview of the designation process, petition preparation, and how and where to submit petition information. Also included is general information about the Sole Source Aquifer program.

  18. An evaluation of aquifer intercommunication between the unconfined and Rattlesnake Ridge aquifers on the Hanford Site

    SciTech Connect

    Jensen, E.J.

    1987-10-01

    During 1986, Pacific Northwest Laboratory conducted a study of a portion of the Rattlesnake Ridge aquifer (confined aquifer) that lies beneath the B Pond - Gable Mountain Pond area of the Hanford Site. The purpose was to determine the extent of intercommunication between the unconfined aquifer and the uppermost regionally extensive confined aquifer, referred to as the Rattlesnake Ridge aquifer. Hydraulic head data and chemical data were collected from the ground water in the study area during December 1986. The hydraulic head data were used to determine the effects caused by water discharged to the ground from B Pond on both the water table of the unconfined aquifer and the potentiometric surface of the confined aquifer. The chemical data were collected to determine the extent of chemical constituents migrating from the unconfined aquifer to the confined aquifer. Analysis of chemical constituents in the Rattlesnake Ridge aquifer demonstrated that communication between the unconfined and confined aquifers had occurred. However, the levels of contaminants found in the Rattlesnake Ridge aquifer during this study were below the DOE Derived Concentration Guides.

  19. Decolorization of textile effluent by bitter gourd peroxidase immobilized on concanavalin A layered calcium alginate-starch beads.

    PubMed

    Matto, Mahreen; Husain, Qayyum

    2009-05-30

    Bitter gourd peroxidase immobilized on the surface of concanavalin A layered calcium alginate-starch beads was used for the successful and effective decolorization of textile industrial effluent. Effluent was recalcitrant to the action of bitter gourd peroxidase; however, in the presence of some redox mediators, it was successfully decolorized. Effluent decolorization was maximum (70%) in the presence of 1.0mM 1-hydroxybenzotriazole within 1h of incubation. However, immobilized bitter gourd peroxidase showed maximum decolorization at pH 5.0 and 40 degrees C. Immobilized bitter gourd peroxidase decolorized more than 90% effluent after 3h of incubation in a batch process. The two-reactor system, one reactor containing immobilized peroxidase and the other had activated silica, was quite effective in the decolorization of textile effluent. The system was capable of decolorizing 40% effluent even after 2 months of continuous operation. The absorption spectra of the untreated and treated effluent exhibited a marked difference in absorbance at various wavelengths. Immobilized peroxidase/1-hydroxybenzotriazole system could be employed for the treatment of a large volume of effluent in a continuous reactor.

  20. De Novo Assembly of Bitter Gourd Transcriptomes: Gene Expression and Sequence Variations in Gynoecious and Monoecious Lines.

    PubMed

    Shukla, Anjali; Singh, V K; Bharadwaj, D R; Kumar, Rajesh; Rai, Ashutosh; Rai, A K; Mugasimangalam, Raja; Parameswaran, Sriram; Singh, Major; Naik, P S

    2015-01-01

    Bitter gourd (Momordica charantia L.) is a nutritious vegetable crop of Asian origin, used as a medicinal herb in Indian and Chinese traditional medicine. Molecular breeding in bitter gourd is in its infancy, due to limited molecular resources, particularly on functional markers for traits such as gynoecy. We performed de novo transcriptome sequencing of bitter gourd using Illumina next-generation sequencer, from root, flower buds, stem and leaf samples of gynoecious line (Gy323) and a monoecious line (DRAR1). A total of 65,540 transcripts for Gy323 and 61,490 for DRAR1 were obtained. Comparisons revealed SNP and SSR variations between these lines and, identification of gene classes. Based on available transcripts we identified 80 WRKY transcription factors, several reported in responses to biotic and abiotic stresses; 56 ARF genes which play a pivotal role in auxin-regulated gene expression and development. The data presented will be useful in both functions studies and breeding programs in bitter gourd. PMID:26047102

  1. Examination of the perception of sweet- and bitter-like taste qualities in sucralose preferring and avoiding rats.

    PubMed

    Torregrossa, A-M; Loney, G C; Smith, J C; Eckel, L A

    2015-03-01

    Sucralose avoiding rats detect a bitter-like taste quality in concentrations of sucralose that are strongly preferred over water by sucralose preferring rats. Here, we investigated whether sucralose preferrers (SP) also detect a bitter-like quality in sucralose that may be masked by an increased perception of sucralose's sweet-like quality. A microstructural analysis of sucralose intake revealed that, at concentrations they avoided in preference tests, sucralose avoiders (SA) consumed smaller and fewer bouts of sucralose than SP. Interestingly, the concentration-dependent increase in sucralose preference in SP was not associated with larger bouts or increased lick rate, two measures that are expected to increase with increasing perceived sweetness. This suggests that SP can detect an aversive quality in sucralose, but this perception of a presumably bitter-like quality may be masked by increased salience of a sweet-like quality that sustains high levels of intake in SP. Further evidence for increased sweet-taste perception in SP, relative to SA, was obtained in a second study in which SP consumed more of a palatable sweet-milk diet than SA. These are the first data to suggest that SP are not blind to the bitter-like quality in sucralose, and that there may be differences in sweet-taste perception between SP and SA. PMID:25497078

  2. Development of preparative and analytical methods of the hop bitter acid oxide fraction and chemical properties of its components.

    PubMed

    Taniguchi, Yoshimasa; Matsukura, Yasuko; Taniguchi, Harumi; Koizumi, Hideki; Katayama, Mikio

    2015-01-01

    The bitter acids in hops (Humulus lupulus L.) and beer, such as α-, β-, and iso-α-acids, are known to affect beer quality and display various physiological effects. However, these compounds readily oxidize, and the effect of the oxides on the properties of beer or their potential health benefits are not well understood. In this study, we developed a simple preparative method for the bitter acid oxide fraction derived from hops and designated the constituents as matured hop bitter acids (MHBA). HPLC-PDA-ESI/HRMS and MS(2) revealed that MHBA are primarily composed of α-acid-derived oxides, which possess a common β-tricarbonyl moiety in their structures similar to α-, β-, and iso-α-acids. We also developed a quantitative analytical method of whole MHBA by HPLC, which showed high precision and reproducibility. Using our newly developed method, the concentration of whole MHBA in several commercial beers was evaluated. Our results will promote the study of bitter acid oxides. PMID:25996959

  3. De Novo Assembly of Bitter Gourd Transcriptomes: Gene Expression and Sequence Variations in Gynoecious and Monoecious Lines

    PubMed Central

    Shukla, Anjali; Singh, V. K.; Bharadwaj, D. R.; Kumar, Rajesh; Rai, Ashutosh; Rai, A. K.; Mugasimangalam, Raja; Parameswaran, Sriram; Singh, Major; Naik, P. S.

    2015-01-01

    Bitter gourd (Momordica charantia L.) is a nutritious vegetable crop of Asian origin, used as a medicinal herb in Indian and Chinese traditional medicine. Molecular breeding in bitter gourd is in its infancy, due to limited molecular resources, particularly on functional markers for traits such as gynoecy. We performed de novo transcriptome sequencing of bitter gourd using Illumina next-generation sequencer, from root, flower buds, stem and leaf samples of gynoecious line (Gy323) and a monoecious line (DRAR1). A total of 65,540 transcripts for Gy323 and 61,490 for DRAR1 were obtained. Comparisons revealed SNP and SSR variations between these lines and, identification of gene classes. Based on available transcripts we identified 80 WRKY transcription factors, several reported in responses to biotic and abiotic stresses; 56 ARF genes which play a pivotal role in auxin-regulated gene expression and development. The data presented will be useful in both functions studies and breeding programs in bitter gourd. PMID:26047102

  4. Impacts of 1-Methylcyclopropene and controlled atmosphere established during conditioning on development of bitter pit in ‘Honeycrisp’ apples

    Technology Transfer Automated Retrieval System (TEKTRAN)

    ‘Honeycrisp’ apples are susceptible to develop the physiological disorder bitter pit. This disorder typically develops during storage, but pre-harvest lesion development can also occur. ‘Honeycrisp’ is also chilling sensitive and fruit is typically held at 10-20 oC after harvest for up to 7d to re...

  5. Identification and RP-HPLC-ESI-MS/MS quantitation of bitter-tasting beta-acid transformation products in beer.

    PubMed