WorldWideScience

Sample records for dry cold season

  1. Effects of age and season on haematological parameters of donkeys during the rainy and cold-dry seasons

    Science.gov (United States)

    Zakari, Friday Ocheja; Ayo, Joseph Olusegun; Rekwot, Peter Ibrahim; Kawu, Mohammed Umar

    2015-12-01

    The aim of the study was to investigate the effects of age and season on haematological parameters of donkeys at rest during the rainy and cold-dry seasons. Thirty healthy donkeys divided into three groups based on their age served as the subjects. During each season, blood sample was collected from each donkey thrice, 2 weeks apart, for haematological analysis, and the dry-bulb temperature (DBT), relative humidity (RH) and temperature-humidity index (THI) were obtained thrice each day during the experimental period using standard procedures. During the rainy season, the mean DBT (33.05 ± 0.49 °C), RH (73.63 ± 1.09 %) and THI (84.39 ± 0.71) were higher ( P blood cell (RBC)], haemoglobin concentration (Hb), mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH), platelet count (PLT), leucocyte count [white blood cell (WBC)], lymphocyte count (LYM) and neutrophil/lymphocyte ratio (N/L) were higher ( P < 0.05) in adults than foals during the rainy season. The MCV, MCH, WBC, NEU, LYM and PLT of adult and yearling donkeys were higher ( P < 0.05) during the rainy than the cold-dry season. The PCV, RBC, Hb, MCV, MCH, and NEU of foals were higher in the rainy than the cold-dry season. The N/L of adult and foal donkeys were higher ( P < 0.05) in the rainy than in the cold-dry season. In conclusion, PCV, RBC, Hb and LYM were considerably higher in foals than yearlings or adults during the rainy season, while erythrocytic indices and platelet counts were higher in adults or yearlings than in foals in both seasons. Erythrocytic indices, PLT and N/L were higher in the rainy than the cold-dry season in adults, yearlings and foals.

  2. Assessment of long-term monthly and seasonal trends of warm (cold), wet (dry) spells in Kansas, USA

    Science.gov (United States)

    Dokoohaki, H.; Anandhi, A.

    2013-12-01

    A few recent studies have focused on trends in rainfall, temperature, and frost indicators at different temporal scales using centennial weather station data in Kansas; our study supplements this work by assessing the changes in spell indicators in Kansas. These indicators provide the duration between temperature-based (warm and cold) and precipitation-based (wet and dry) spells. For wet (dry) spell calculations, a wet day is defined as a day with precipitation ≥1 mm, and a dry day is defined as one with precipitation ≤1 mm. For warm (cold) spell calculations, a warm day is defined as a day with maximum temperature >90th percentile of daily maximum temperature, and a cold day is defined as a day with minimum temperature spell indicators are calculated: Average Wet Spell Length (AWSL), Dry Spell Length (ADSL), Average Warm Spell Days (AWSD) and Average Cold Spell Days (ACSD) are calculated. Data were provided from 23 centennial weather stations across Kansas, and all calculations were done for four time periods (through 1919, 1920-1949, 1950-1979, and 1980-2009). The definitions and software provided by Expert Team on Climate Change Detection and Indices (ETCCDI) were adapted for application to Kansas. The long- and short-term trends in these indices were analyzed at monthly and seasonal timescales. Monthly results indicate that ADSL is decreasing and AWSL is increasing throughout the state. AWSD and ACSD both showed an overall decreasing trend, but AWSD trends were variable during the beginning of the Industrial Revolution. Results of seasonal analysis revealed that the fall season recorded the greatest increasing trend for ACSD and the greatest decreasing trend for AWSD across the whole state and during all time periods. Similarly, the greatest increasing and decreasing trends occurred in winter for AWSL and ADSL, respectively. These variations can be important indicators of climatic change that may not be represented in mean conditions. Detailed geographical

  3. Cold Vacuum Drying Facility

    Data.gov (United States)

    Federal Laboratory Consortium — Located near the K-Basins (see K-Basins link) in Hanford's 100 Area is a facility called the Cold Vacuum Drying Facility (CVDF).Between 2000 and 2004, workers at the...

  4. Cold vacuum drying facility design requirements

    Energy Technology Data Exchange (ETDEWEB)

    IRWIN, J.J.

    1999-07-01

    This document provides the detailed design requirements for the Spent Nuclear Fuel Project Cold Vacuum Drying Facility. Process, safety, and quality assurance requirements and interfaces are specified.

  5. Cold vacuum drying facility design requirements

    Energy Technology Data Exchange (ETDEWEB)

    Irwin, J.J.

    1997-09-24

    This release of the Design Requirements Document is a complete restructuring and rewrite to the document previously prepared and released for project W-441 to record the design basis for the design of the Cold Vacuum Drying Facility.

  6. Impacts of "wet seasons get wetter, dry seasons get drier"

    Science.gov (United States)

    Chou, C.; Lan, C.; Lee, C.; Chung, C.; Laio, Y.; Chiang, J. C.

    2012-12-01

    Global temperatures have increased for the past few decades. Changes to the global hydrological cycle have also been observed, but with a greater uncertainty and a strong spatial variation. The most robust change is that wet regions get wetter and dry regions get drier. Here we demonstrate that the tendency of wet-get-wetter and dry-get-drier occurs over the course of the seasonal cycle: wet seasons get wetter and dry seasons get drier, enhancing the annual precipitation range. Over 1979-2010, the globally-averaged changes in precipitation are 13.64±2.86%°C-1, -39.73±7.38%°C-1 and 33.03±6.42%°C-1 respectively for wet seasons, dry seasons, and the annual range. The trend magnitudes vary over a shorter evaluation period (1988-2010), but the sign of the tendencies remain the same. The magnitudes of these globally-averaged trends imply an inconclusive change in the strength of the corresponding tropical circulation. Regionally, the "wet seasons get wetter (dry seasons get drier)" tendency occurs over areas with greater (less) annual mean precipitation. The enhanced annual precipitation range may strongly impact local agriculture and water resources even in situations where the annual mean precipitation does not change significantly.

  7. Cold Vacuum Drying Facility hazard analysis report

    Energy Technology Data Exchange (ETDEWEB)

    Krahn, D.E.

    1998-02-23

    This report describes the methodology used in conducting the Cold Vacuum Drying Facility (CVDF) hazard analysis to support the CVDF phase 2 safety analysis report (SAR), and documents the results. The hazard analysis was performed in accordance with DOE-STD-3009-94, Preparation Guide for US Department of Energy Nonreactor Nuclear Facility Safety Analysis Reports, and implements the requirements of US Department of Energy (DOE) Order 5480.23, Nuclear Safety Analysis Reports.

  8. Two cold-season derechoes in Europe

    Science.gov (United States)

    Gatzen, Christoph; Púčik, Tomas; Ryva, David

    2011-06-01

    In this study, we apply for the first time the definition of a derecho (Johns and Hirt, 1987) to European cold-season convective storm systems. These occurred on 18 January 2007 and 1 March 2008, respectively, and they are shown to fulfill the criteria of a derecho. Damaging winds were reported over a distance of 1500 km and locally reached F3 intensity. Synoptic analysis for the events reveal strongly forced situations that have been described for cold-season derechoes in the United States. A comparison of swaths of damaging winds, radar structures, detected lightning, cold pool development, and cloud-top temperatures indicates that both derechoes formed along cold fronts that were affected by strong quasi-geostrophic forcing. It seems that the overlap of the cold front position with the strong differential cyclonic vorticity advection at the cyclonic flank of mid-level jet streaks favoured intense convection and high winds. The movement and path width of the two derechoes seemed to be related to this overlap. The wind gust intensity that was also different for both events is discussed and could be related to the component of the mid-level winds perpendicular to the gust fronts.

  9. Ozone measurements in Amazonia - Dry season versus wet season

    Science.gov (United States)

    Kirchhoff, V. W. J. H.; Da Silva, I. M. O.; Browell, Edward V.

    1990-01-01

    Recent ozone measurements taken in the Amazonian rain forest environment during the wet season (April-May 1987) are described, revealling new aspects of the regional atmospheric chemistry. The measurements were part of the Amazon Boundary Layer Experiment (ABLE 2B) mission and utilized UV absorption as a measurement technique to obtain surface ozone data; 20 ozonesondes were launched in order to obtain vertical ozone profiles used to describe the upper troposphere and stratosphere. The major differences in comparison to a previous dry season experiment, which found ozone concentrations to be lower in the whole troposphere by nearly a factor of 2, are stressed.

  10. Diurnal Chemical Characterization of Aerosols at Downtown Mexico City During the Cold dry Seasons of 2003 and 2005. Part I. Data Validation

    Science.gov (United States)

    Grutter, M.; Moya, M.; Matias, E.; Baez, A.

    2006-12-01

    Data of size-differentiated (0.18-10 μm) and bulk (1, 2.5 μm) inorganic aerosols collected during February-March of 2003 and 2005 at a site near downtown Mexico City are analyzed and discussed in the present work. Physico-chemical consistency tests applied on the data base showed a reliability of 85%. Highest concentrations of PM occurred mainly in fine size ranges, i.e., accumulation mode (size-differentiated) and fine (PM1), specifically during the morning sampling periods. Sulfate, nitrate and ammonium were the dominant species though higher concentrations of NaCl were observed during the 2003 field campaign. Concentration of this species is explained in terms of the potential influence of the nearby dry salt-lake of Texcoco. Electroneutrality balances are achieved for all size ranges: PM10 (size-differentiated), PM2.5 and PM1 indicating the significant presence of gas-phase NH3 (> 40 ppb) observed consistently during the morning sampling periods in the Valley of Mexico was of importance in providing enough NH4+ to neutralize observed sulfate concentrations. Measured PM2.5 during the 2005 field campaign was exceeding several times the recent issued (November 2005) PM2.5 Mexican standard of 65 μg/m3.

  11. Cold Vacuum Drying (CVD) Facility, Diesel Generator Fire Protection

    CERN Document Server

    Singh, G

    2000-01-01

    This Acceptance Test Procedure (ATP) has been prepared to demonstrate that the Fire Protection and Detection System installed by Project W-441 (Cold Vacuum Drying Facility and Diesel Generator Building) functions as required by project specifications.

  12. GCM simulations of cold dry Snowball Earth atmospheres

    Science.gov (United States)

    Voigt, A.; Held, I.; Marotzke, J.

    2009-12-01

    We use the full-physics atmospheric general circulation model ECHAM5 to investigate cold and virtually dry Snowball Earth atmospheres. These result from specifying sea ice as the surface boundary condition everywhere, corresponding to a frozen aquaplanet, while keeping total solar irradiance at its present-day value of 1365 Wm-2 and setting atmospheric carbon dioxide to 300 ppmv. Here, we present four simulations corresponding to the four possible combinations of enabled or disabled diurnal and seasonal cycles. The aim of this study is twofold. First, we focus on the zonal-mean circulation of Snowball Earth atmospheres, which, due to missing moisture, might constitute an ideal though yet unexplored testbed for theories of atmospheric dynamics. Second, we investigate tropical surface temperatures with an emphasis on the impact of the diurnal and seasonal cycles. This will indicate whether the presence of the diurnal or seasonal cycle would facilitate or anticipate the escape from Snowball Earth conditions when total solar irradiance or atmospheric CO2 levels were increased. The dynamics of the tropical circulation in Snowball Earth atmospheres differs substantially from that in the modern atmosphere. The analysis of the mean zonal momentum budget reveals that the mean flow meridional advection of absolute vorticity is primarily balanced by vertical diffusion of zonal momentum. The contribution of eddies is found to be even smaller than the contribution of mean flow vertical advection of zonal momentum, the latter being usually neglected in theories for the Hadley circulation, at least in its upper tropospheric branch. Suppressing vertical diffusion of horizontal momentum above 850 hPa leads to a stronger Hadley circulation. This behaviour cannot be understood from axisymmetric models of the atmosphere, nor idealized atmospheric general circulation models, which both predict a weakening of the Hadley circulation when the vertical viscosity is decreased globally. We

  13. Cold vacuum drying facility 90% design review

    Energy Technology Data Exchange (ETDEWEB)

    O`Neill, C.T.

    1997-05-02

    This document contains review comment records for the CVDF 90% design review. Spent fuels retrieved from the K Basins will be dried at the CVDF. It has also been recommended that the Multi-Conister Overpacks be welded, inspected, and repaired at the CVD Facility before transport to dry storage.

  14. Spent nuclear fuel project cold vacuum drying facility operations manual

    Energy Technology Data Exchange (ETDEWEB)

    IRWIN, J.J.

    1999-05-12

    This document provides the Operations Manual for the Cold Vacuum Drying Facility (CVDF). The Manual was developed in conjunction with HNF-SD-SNF-SAR-002, Safety Analysis Report for the Cold Vacuum Drying Facility, Phase 2, Supporting Installation of Processing Systems (Garvin 1998) and, the HNF-SD-SNF-DRD-002, 1997, Cold Vacuum Drying Facility Design Requirements, Rev. 3a. The Operations Manual contains general descriptions of all the process, safety and facility systems in the CVDF, a general CVD operations sequence, and has been developed for the SNFP Operations Organization and shall be updated, expanded, and revised in accordance with future design, construction and startup phases of the CVDF until the CVDF final ORR is approved.

  15. Cold Vacuum Drying (CVD) Facility Technical Safety Requirements

    Energy Technology Data Exchange (ETDEWEB)

    KRAHN, D.E.

    2000-08-08

    The Technical Safety Requirements (TSRs) for the Cold Vacuum Drying Facility define acceptable conditions, safe boundaries, bases thereof, and management or administrative controls required to ensure safe operation during receipt of multi-canister overpacks (MCOs) containing spent nuclear fuel. removal of free water from the MCOs using the cold vacuum drying process, and inerting and testing of the MCOs before transport to the Canister Storage Building. Controls required for public safety, significant defense in depth, significant worker safety, and for maintaining radiological and toxicological consequences below risk evaluation guidelines are included.

  16. Cold Vacuum Drying Facility Stack Air Sampling System Qualification Tests

    Energy Technology Data Exchange (ETDEWEB)

    Glissmeyer, John A.

    2001-01-24

    This report documents tests that were conducted to verify that the air monitoring system for the Cold Vacuum Drying Facility ventilation exhaust stack meets the applicable regulatory criteria regarding the placement of the air sampling probe, sample transport, and stack flow measurement accuracy.

  17. Cold Vacuum Drying (CVD) Electrical System Design Description

    Energy Technology Data Exchange (ETDEWEB)

    BRISBIN, S.A.

    1999-06-17

    This document provides a technical explanation of the design and operation of the electrical system for the Cold Vacuum Drying Facility. This document identifies the requirements, and the basis for the requirements and details on how the requirements have been implemented in the design and construction of the facility. This document also provides general guidance for the surveillance, testing, and maintenance of this system.

  18. Cold Vacuum Drying (CVD) Facility Design Basis Accident Analysis Documentation

    Energy Technology Data Exchange (ETDEWEB)

    PIEPHO, M.G.

    1999-10-20

    This document provides the detailed accident analysis to support HNF-3553, Annex B, Spent Nuclear Fuel Project Final Safety Analysis Report, ''Cold Vacuum Drying Facility Final Safety Analysis Report (FSAR).'' All assumptions, parameters and models used to provide the analysis of the design basis accidents are documented to support the conclusions in the FSAR.

  19. Fire Hazard Analysis for the Cold Vacuum Drying (CVD) Facility

    Energy Technology Data Exchange (ETDEWEB)

    JOHNSON, B.H.

    1999-08-19

    This Fire Hazard Analysis assesses the risk from fire within individual fire areas in the Cold Vacuum Drying Facility at the Hanford Site in relation to existing or proposed fire protection features to ascertain whether the objectives of DOE Order 5480.7A Fire Protection are met.

  20. Rural Women\\'s Involvement In Dry Season Vegetable Production ...

    African Journals Online (AJOL)

    Rural Women\\'s Involvement In Dry Season Vegetable Production And Marketing In Ezinihitte Local Government Area Of Imo State, Nigeria. ... On the other hand, education and income were negative and statistically significant at 1% and 5% ...

  1. Cold Vacuum Drying (CVD) Electrical System Design Description

    Energy Technology Data Exchange (ETDEWEB)

    SINGH, G.

    2000-05-01

    This system design description (SDD) provides a technical explanation of the design and operation of the electrical system for the Cold Vacuum Drying Facility (CVDF). This SDD also identifies the requirements, and the basis for the requirements and details on how the requirements have been implemented in the design and construction of the facility. This SDD also provides general guidance for the surveillance, testing, and maintenance of this system.

  2. Cold Vacuum Drying (CVD) Facility Hazards Analysis Report

    Energy Technology Data Exchange (ETDEWEB)

    CROWE, R.D.

    2000-08-07

    This report describes the methodology used in conducting the Cold Vacuum Drying Facility (CVDF) Hazard Analysis to support the CVDF Final Safety Analysis Report and documents the results. The hazard analysis was performed in accordance with DOE-STD-3009-94, ''Preparation Guide for US. Department of Energy Nonreactor Nuclear Facility Safety Analysis Reports,'' and implements the requirements of DOE Order 5480.23, ''Nuclear Safety Analysis Reports.''

  3. Gas Composition Transients in the Cold Vacuum Drying (CVD) Facility

    Energy Technology Data Exchange (ETDEWEB)

    PACKER, M.J.

    2000-05-10

    The purpose of this document is to evaluate selected problems involving the prediction of transient gas compositions during Cold Vacuum Drying operations. The problems were evaluated to answer specific design questions. The document is formatted as a topical report with each section representing a specific problem solution. The problem solutions are reported in the calculation format specified in HNF-1613, Rev. 0, EP 7.6.

  4. Cold Vacuum Drying facility design basis accident analysis documentation

    Energy Technology Data Exchange (ETDEWEB)

    CROWE, R.D.

    2000-08-08

    This document provides the detailed accident analysis to support HNF-3553, Annex B, Spent Nuclear Fuel Project Final Safety Analysis Report (FSAR), ''Cold Vacuum Drying Facility Final Safety Analysis Report.'' All assumptions, parameters, and models used to provide the analysis of the design basis accidents are documented to support the conclusions in the FSAR. The calculations in this document address the design basis accidents (DBAs) selected for analysis in HNF-3553, ''Spent Nuclear Fuel Project Final Safety Analysis Report'', Annex B, ''Cold Vacuum Drying Facility Final Safety Analysis Report.'' The objective is to determine the quantity of radioactive particulate available for release at any point during processing at the Cold Vacuum Drying Facility (CVDF) and to use that quantity to determine the amount of radioactive material released during the DBAs. The radioactive material released is used to determine dose consequences to receptors at four locations, and the dose consequences are compared with the appropriate evaluation guidelines and release limits to ascertain the need for preventive and mitigative controls.

  5. Assessment of a GOES microburst product for two early cold season convective storms

    CERN Document Server

    Pryor, Kenneth L

    2010-01-01

    This paper presents an assessment of the new Geostationary Operational Environmental Satellite (GOES) imager channel 3 - 4 brightness temperature difference (BTD) product for two early cold season severe convective storm events that occurred over the Mid-Atlantic region on 17 November and 1 December 2010. Both of these events involved squall lines that produced strong downbursts as they tracked over the Tidal Potomac River and Chesapeake Bay regions. It has been found recently that the BTD between GOES infrared channel 3 (water vapor) and channel 4 (thermal infrared) can highlight regions where severe outflow wind generation (i.e. downbursts, microbursts) is likely due to the channeling of dry mid-tropospheric air into the precipitation core of a deep, moist convective storm. These two cases demonstrate effective operational use of this image product for cold-season convective storm events.

  6. Floristics and biogeography of vegetation in seasonally dry tropical regions

    DEFF Research Database (Denmark)

    Dexter, K.G.; Smart, B.; Baldauf, C.

    2015-01-01

    To provide an inter-continental overview of the floristics and biogeography of drought-adapted tropical vegetation formations, we compiled a dataset of inventory plots in South America (n=93), Africa (n=84), and Asia (n=92) from savannas (subject to fire), seasonally dry tropical forests (not gen...

  7. Variability in cold front activities modulating cool-season evaporation from a southern inland water in the USA

    Science.gov (United States)

    Liu, Heping; Blanken, Peter D.; Weidinger, Tamas; Nordbo, Annika; Vesala, Timo

    2011-04-01

    Understanding seasonal variations in the evaporation of inland waters (e.g., lakes and reservoirs) is important for water resource management as well as the prediction of the hydrological cycles in response to climate change. We analyzed eddy covariance-based evaporation measurements from the Ross Barnett Reservoir (32°26'N, 90°02'W which is always ice-free) in central Mississippi during the cool months (i.e., September-March) of 2007 and 2008, and found that the variability in cold front activities (i.e., passages of cold fronts and cold/dry air masses behind cold fronts) played an important role in modulating the exchange of sensible (H) and latent (λE) heat fluxes. Our analysis showed that 2007's warmer cool season had smaller mean H and λE than 2008's cooler cool season. This implies that the warmer cool season did not accelerate evaporation and heat exchange between the water surface and the atmosphere. Instead, more frequent cold fronts and longer periods of cold/dry air masses behind the cold fronts in 2008 resulted in overall larger H and λE as compared with 2007, this primarily taking the form of sporadic short-term rapid 'pulses' of H and λE losses from the water's surface. These results suggest that future climate-induced changes in frequency of cold fronts and the meteorological properties of the air masses behind cold fronts (e.g., wind speeds, temperature, and humidity), rather than other factors of climate change, would produce significant variations in the water surface's energy fluxes and subsequent evaporation rates.

  8. Cold Vacuum Drying (CVD) OCRWM Loop Error Determination

    Energy Technology Data Exchange (ETDEWEB)

    PHILIPP, B.L.

    2000-07-26

    Characterization is specifically identified by the Richland Operations Office (RL) for the Office of Civilian Radioactive Waste Management (OCRWM) of the US Department of Energy (DOE), as requiring application of the requirements in the Quality Assurance Requirements and Description (QARD) (RW-0333P DOE 1997a). Those analyses that provide information that is necessary for repository acceptance require application of the QARD. The cold vacuum drying (CVD) project identified the loops that measure, display, and record multi-canister overpack (MCO) vacuum pressure and Tempered Water (TW) temperature data as providing OCRWM data per Application of the Office of Civilian Radioactive Waste Management (OCRWM) Quality Assurance Requirements to the Hanford Spent Nuclear Fuel Project HNF-SD-SNF-RPT-007. Vacuum pressure transmitters (PT 1*08, 1*10) and TW temperature transmitters (TIT-3*05, 3*12) are used to verify drying and to determine the water content within the MCO after CVD.

  9. Human factors engineering report for the cold vacuum drying facility

    Energy Technology Data Exchange (ETDEWEB)

    IMKER, F.W.

    1999-06-30

    The purpose of this report is to present the results and findings of the final Human Factors Engineering (HFE) technical analysis and evaluation of the Cold Vacuum Drying Facility (CVDF). Ergonomics issues are also addressed in this report, as appropriate. This report follows up and completes the preliminary work accomplished and reported by the Preliminary HFE Analysis report (SNF-2825, Spent Nuclear Fuel Project Cold Vacuum Drying Facility Human Factors Engineering Analysis: Results and Findings). This analysis avoids redundancy of effort except for ensuring that previously recommended HFE design changes have not affected other parts of the system. Changes in one part of the system may affect other parts of the system where those changes were not applied. The final HFE analysis and evaluation of the CVDF human-machine interactions (HMI) was expanded to include: the physical work environment, human-computer interface (HCI) including workstation and software, operator tasks, tools, maintainability, communications, staffing, training, and the overall ability of humans to accomplish their responsibilities, as appropriate. Key focal areas for this report are the process bay operations, process water conditioning (PWC) skid, tank room, and Central Control Room operations. These key areas contain the system safety-class components and are the foundation for the human factors design basis of the CVDF.

  10. Cold season soil NO fluxes from a temperate forest: drivers and contribution to annual budgets

    Science.gov (United States)

    Medinets, S.; Gasche, R.; Skiba, U.; Schindlbacher, A.; Kiese, R.; Butterbach-Bahl, K.

    2016-11-01

    Soils, and here specifically acidic forest soils exposed to high rates of atmospheric nitrogen deposition, are a significant source for the secondary greenhouse gas nitric oxide (NO). However, as flux estimates are mainly based on measurements during the vegetation period, annual NO emissions budgets may hold uncertainty as cold season soil NO fluxes have rarely been quantified. Here we analyzed cold season soil NO fluxes and potential environmental drivers on the basis of the most extensive database on forest soil NO fluxes obtained at the Höglwald Forest, Germany, spanning the years 1994 to 2010. On average, the cold season (daily average air temperature soil NO budget, varying from 13% to 41% between individual cold seasons. Temperature was the main controlling factor of the cold season NO fluxes, whereas during freeze-thaw cycles soil moisture availability determined NO emission rates. The importance of cold season soil NO fluxes for annual NO fluxes depended positively on the length of the cold season, but responded negatively to frost events. Snow cover did not significantly affect cold season soil NO fluxes. Cold season NO fluxes significantly correlated with cold season soil carbon dioxide (CO2) emissions. During freeze-thaw periods strong positive correlations between NO and N2O fluxes were observed, though stimulation of NO fluxes by freeze-thaw was by far less pronounced as compared to N2O. Except for freeze-thaw periods NO fluxes significantly exceeded those for N2O during the cold season period. We conclude that in temperate forest ecosystems cold season NO emissions can contribute substantially to the annual NO budget and this contribution is significantly higher in years with long lasting but mild (less frost events) cold seasons.

  11. Design verification and validation plan for the cold vacuum drying facility

    Energy Technology Data Exchange (ETDEWEB)

    NISHIKAWA, L.D.

    1999-06-03

    The Cold Vacuum Drying Facility (CVDF) provides the required process systems, supporting equipment, and facilities needed for drying spent nuclear fuel removed from the K Basins. This document presents the both completed and planned design verification and validation activities.

  12. Dry-season ultraviolet radiation primes litter for wet season decomposition in a Mediterranean grassland

    Science.gov (United States)

    Baker, N. R.; Allison, S. D.

    2013-12-01

    Traditional decomposition models developed in mesic ecosystems often consistently underestimate rates of decomposition in more arid ecosystems such as deserts and Mediterranean grasslands. Photodegradation of plant litter by ultraviolet radiation (UV) is hypothesized to be one of the mechanisms accounting for the greater-than-expected rates of decomposition observed in these ecosystems. Putatively, photodegradation preferentially degrades complex aromatic compounds in litter such as lignin, whose decomposition is considered a rate-limiting step in the microbial decomposition of plant litter. This study tested the effects of attenuated ultraviolet radiation on the decomposition of two litter types over the course of a year in a Southern California Mediterranean grassland. The two types of litter differed primarily in lignin content to test for a differential effect of UV on high-lignin versus low-lignin litter. Rates of litter mass loss, changes in litter chemistry, and changes in microbial activity and microbial biomass were observed, and assays of extracellular enzymes were conducted at 5 points through the year, beginning during the dry season and continuing until the end of the following dry season. Litter exposed to attenuated ultraviolet radiation during the dry season had lower rates of mass loss than litter exposed to ambient radiation (6.1% vs. 8.6%, respectively, p peroxidase in high-lignin, ambient UV samples was 85.9 μmol/hr*g during the wet season, compared to 44.1 μmol/hr*g in attenuated UV samples (p production. Similarly, the reduced potential oxidative enzyme activity in high-lignin samples exposed to attenuated UV may indicate that photodegradation is necessary to facilitate the breakdown of more complex compounds such as lignin by microbial decomposers. We conclude that while abiotic factors such as photodegradation can have a significant effect on the mechanisms of plant matter decomposition in semiarid ecosystems, these effects are not only

  13. Comparison of Ant Community Diversity and Functional Group Composition Associated to Land Use Change in a Seasonally Dry Oak Forest.

    Science.gov (United States)

    Cuautle, M; Vergara, C H; Badano, E I

    2016-04-01

    Ants have been used to assess land use conversion, because they reflect environmental change, and their response to these changes have been useful in the identification of bioindicators. We evaluated ant diversity and composition associated to different land use change in a temperate forest (above 2000 m asl) in Mexico. The study was carried out in "Flor del Bosque" Park a vegetation mosaic of native Oak Forests and introduced Eucalyptus and grasslands. Species richness, dominance and diversity rarefaction curves, based on ant morphospecies and functional groups, were constructed and compared among the three vegetation types, for the rainy and the dry seasons of 2008-2009. Jaccard and Sorensen incidence-based indices were calculated to obtain similarity values among all the habitats. The Oak Forest was a rich dominant community, both in species and functional groups; the Eucalyptus plantation was diverse with low dominance. The most seasonality habitat was the grassland, with low species and high functional group diversity during the dry seasons, but the reverse pattern during the wet season. The Oak Forest was more similar to the Eucalyptus plantation than to the grassland, particularly during the dry season. Oak Forests are dominated by Cold Climate Specialists, specifically Prenolepis imparis (Say). The Eucalyptus and the grassland are characterized by generalized Myrmicinae, as Pheidole spp. and Monomorium ebenium (Forel). The conservation of the native Oak Forest is primordial for the maintenance of Cold Climate Specialist ant communities. The microclimatic conditions in this forest, probably, prevented the invasion by opportunistic species.

  14. Population dynamic of the swallowtail butterfly, Papilio polytes (Lepidoptera: Papilionidae) in dry and wet seasons

    OpenAIRE

    SUWARNO

    2010-01-01

    Suwarno (2010) Population dynamic of the swallowtail butterfly, Papilio polytes (Lepidoptera: Papilionidae) in dry and wet seasons. Biodiversitas 11: 19-23. The population dynamic of Papilio polytes L. (Lepidoptera: Papilionidae) in dry and wet seasons was investigated in the citrus orchard in Tasek Gelugor, Pulau Pinang, Malaysia. Population of immature stages of P. polytes was observed alternate day from January to March 2006 (dry season, DS), from April to July 2006 (secondary wet season, ...

  15. Carbon allocation in a Bornean tropical rainforest without dry seasons.

    Science.gov (United States)

    Katayama, Ayumi; Kume, Tomonori; Komatsu, Hikaru; Saitoh, Taku M; Ohashi, Mizue; Nakagawa, Michiko; Suzuki, Masakazu; Otsuki, Kyoichi; Kumagai, Tomo'omi

    2013-07-01

    To clarify characteristics of carbon (C) allocation in a Bornean tropical rainforest without dry seasons, gross primary production (GPP) and C allocation, i.e., above-ground net primary production (ANPP), aboveground plant respiration (APR), and total below-ground carbon flux (TBCF) for the forest were examined and compared with those from Amazonian tropical rainforests with dry seasons. GPP (30.61 MgC ha(-1) year(-1), eddy covariance measurements; 34.40 MgC ha(-1) year(-1), biometric measurements) was comparable to those for Amazonian rainforests. ANPP (6.76 MgC ha(-1) year(-1)) was comparable to, and APR (8.01 MgC ha(-1) year(-1)) was slightly lower than, their respective values for Amazonian rainforests, even though aboveground biomass was greater at our site. TBCF (19.63 MgC ha(-1) year(-1)) was higher than those for Amazonian forests. The comparable ANPP and higher TBCF were unexpected, since higher water availability would suggest less fine root competition for water, giving higher ANPP and lower TBCF to GPP. Low nutrient availability may explain the comparable ANPP and higher TBCF. These data show that there are variations in C allocation patterns among mature tropical rainforests, and the variations cannot be explained solely by differences in soil water availability.

  16. European cold season lightning map for wind turbines based on radio soundings

    DEFF Research Database (Denmark)

    Vogel, Stephan; Holbøll, Joachim; Lopez, Javier;

    2016-01-01

    In this paper, the meteorological data of cold season thunderstorms in Japan and Spain are reviewed to determine the threshold conditions at which cold season lightning was recorded in the past. The variables investigated are the height of the -10°C and 0°C isotherms above ground, the wind veloci...

  17. Wet season upwelling and dry season chlorophyll-a describe interannual growth rates of Porites in southern China.

    Directory of Open Access Journals (Sweden)

    Teng Teng Yang

    Full Text Available Southern China hosts coral communities in marginal environments that are characterized by low linear extension rates, low coral cover and/or no reef formation, thus providing natural laboratories to study coral communities with below average growth rates. Here we compare the annual linear extension rates over 10 years (range 1.2 to 11.4 mm yr-1 of six Porites sp. coral cores collected from Hong Kong with monthly hydrographic data from the Hong Kong Environmental Protection Department. At all sites, low-density, dry season extension were more variable than high-density, wet season extension and on average, was lower at two of the three sites. We applied multi-variate linear regressions that revealed high-density, wet season band extension to inversely correlate most significantly to temperature (r = -0.39, p<0.01. In contrast, low-density, dry season band extension was more variable and correlated most significantly with dry season chlorophyll-a (Chl-a (r = 0.64, p<0.001. Additionally, we find that corals at the site with highest dry season Chl-a have the highest dry season extension lengths. Our findings indicate that relative mixing of fresh and salt water in the wet season and primary productivity in the dry season, and their influences on aragonite saturation, are likely to impact interannual coral extension variability in marginal environments.

  18. Significance of cold-season respiration and photosynthesis in a subarctic heath ecosystem in Northern Sweden

    DEFF Research Database (Denmark)

    Larsen, Klaus Steenberg; Ibrom, A.; Jonasson, S.

    2007-01-01

    While substantial cold-season respiration has been documented in most arctic and alpine ecosystems in recent years, the significance of cold-season photosynthesis in these biomes is still believed to be small. In a mesic, subartic heath during both the cold and warm season, we measured in situ...... ecosystem respiration and photosynthesis with a chamber technique at ambient conditions and at artificially, increased frequency of freeze-thaw (FT) cycles during fall and spring. We fitted the measured ecosystem exchange rates to respiration and photosynthesis models with R-2-values ranging from 0.81 to 0.......85. As expected, estimated cold-season (October, November, April and May) respiration was significant and accounted for at least 22% of the annual respiratory CO2 flux. More surprisingly, estimated photosynthesis during this period accounted for up to 19% of the annual gross CO2 uptake, suggesting that cold...

  19. Satellite observations of the role and impacts of dry season climate limitations on tropical forest fates

    Science.gov (United States)

    Huete, A. R.; Restrepo-Coupe, N.; Wu, J.; Devadas, R.; Guan, K.; Liu, Y.; Ratana, P.; Sun, Q.; Schaaf, C.; Saleska, S. R.

    2015-12-01

    Climate change scenarios projected for the 21st century predict drying of the Amazon, greening of monsoon tropical Asia and no change in the tropics of Australia. Dry season variability is increasing with complex associated forest responses and feedbacks as they become exposed to longer and/or more intense dry seasons. The functional response of tropical forests to dry seasonal periods is thus crucial to forest resilience, as forests may respond with either enhanced photosynthesis (due to more sunlight) or may dry down with greater susceptibility to fires and release of greenhouse gases and severe public health haze alerts. In this study, we use multiple satellite remote sensing datasets representing forest canopy states, environmental drivers (light and water status), and disturbance (fires), along with in situ flux tower measures of photosynthesis to assess whole ecosystem patterns and test mechanisms of forest- dry season climate interactions. We compare photosynthesis patterns and dry season responses of Asia-Oceania tropical forests with neotropical forests to better understand forest resilience to climate change and human impacts. In contrast to the neotropics, human activities in monsoon tropical Asia have resulted in intensive transformations of tropical forests. We find forest disturbance exerts a strong influence on tropical forest functioning and a partial loss or degradation of tropical forests can reverse dry seasonal responses with substantial impacts on carbon fluxes. Neotropical forests displayed large variations in dry season forest responses due to spatially variable dry season lengths and magnitude, whereas most of monsoon Asia tropical forests lacked well-defined dry seasons, yet were highly sensitive to shorter term, intense drought events that impacted severely upon the disturbed forests. Our results highlight the interactions among rainfall, radiation and forest health with the relative importance of each factor varying with the

  20. Decreasing but still significant facilitation effect of cold-season macrophytes on wetlands purification function during cold winter

    OpenAIRE

    Xiangxu Zou; Hui Zhang; Jie Zuo; Penghe Wang; Dehua Zhao; Shuqing An

    2016-01-01

    To identify the facilitation effect of a cool-season aquatic macrophyte (FEam) for use in effluent purification via constructed floating wetlands (CFWs) and to determine the possible pathways used during a winter period with an average temperature of less than 5??C, pilot-scale CFWs were planted with the cold-season macrophyte Oenanthe clecumbens and were operated as batch systems. Although some leaves withered, the roots retained relatively high levels of activity during the winter, which ha...

  1. Spatial variability of soils in a seasonally dry tropical forest

    Science.gov (United States)

    Pulla, Sandeep; Riotte, Jean; Suresh, Hebbalalu; Dattaraja, Handanakere; Sukumar, Raman

    2016-04-01

    Soil structures communities of plants and soil organisms in tropical forests. Understanding the controls of soil spatial variability can therefore potentially inform efforts towards forest restoration. We studied the relationship between soils and lithology, topography, vegetation and fire in a seasonally dry tropical forest in southern India. We extensively sampled soil (available nutrients, Al, pH, and moisture), rocks, relief, woody vegetation, and spatial variation in fire burn frequency in a permanent 50-ha plot. Lower elevation soils tended to be less moist and were depleted in several nutrients and clay. The availability of several nutrients was, in turn, linked to whole-rock chemical composition differences since some lithologies were associated with higher elevations, while the others tended to dominate lower elevations. We suggest that local-scale topography in this region has been shaped by the spatial distribution of lithologies, which differ in their susceptibility to weathering. Nitrogen availability was uncorrelated with the presence of trees belonging to Fabaceae, a family associated with N-fixing species. No effect of burning on soil parameters could be discerned at this scale.

  2. Comparison of Freshwater Mollusc Assemblages between Dry and Rainy Season in Situ Gede System, Bogor, Indonesia

    Science.gov (United States)

    Priawandiputra, W.; Nasution, D. J.; Prawasti, T. S.

    2017-03-01

    Anthropogenic activities, which reduced and damaged natural situ (freshwater ponds), also reduced fauna diversity in its aquatic ecosystem. Freshwater molluscs in the situ, one of the largest numbers of animals group with documented extinction, may also be impacted. The aims of this study were to record and to compare the abundance and species composition of freshwater molluscs between dry and rainy season in three situ. The freshwater molluscs were determined by twelve sampling points in Situ Gede (SG), Situ Panjang (SP) and Situ Burung (SB). Samplings were conducted once during dry season (August 2015) and rainy season (February 2016). Total abundance of molluscs encountered was 4321 individuals, which was comprised of 76 bivalve individuals (1.75 %) and 4245 gastropods individuals (98.44%). The abundance of molluscs were generally higher in rainy season than in dry season in all situ, while species richness showed the contrary. The species composition was significantly different between dry and rainy season in SP and SB but no significant differences was found in SG. From eight dominant species, there were six dominant species such as Filopaludina javanica, Melanoides tuberculata, Thiara scabra, Sermyla requeti, Pila scutata (gastropods) and Pilsbryoconcha exilis (bivalve) which were found in high numbers during dry season while two gastropod species (Pomacea canaliculata and Wattebledia crosseana) was numbered higher in rainy season than dry season.

  3. Diverse patterns of stored water use among saplings in seasonally dry tropical forests.

    Science.gov (United States)

    Wolfe, Brett T; Kursar, Thomas A

    2015-12-01

    Tree species in seasonally dry tropical forests likely vary in their drought-survival mechanisms. Drought-deciduousness, which reduces water loss, and low wood density, which may permit dependence on stored water, are considered key traits. For saplings of six species at two distinct sites, we studied these and two associated traits: the seasonal amount of water released per stem volume ("water released") and the hydraulic capacitance of the stem (C). Two deciduous species with low stem density, Cavanillesia platanifolia and Bursera simaruba, had high C and high dry-season stem water potential (Ψ(stem)), but differed in dry-season water released. C. platanifolia did not use stored water during the dry season whereas B. simaruba, in a drier forest, released stored water. In both, water released was highest while flushing leaves, suggesting that stored water supports leaf flushing. In contrast, two deciduous species with intermediate stem density, Annona hayesii and Genipa americana, had intermediate C, low dry-season Ψ(stem), and high seasonal change in water released. Meanwhile, two evergreen species with intermediate stem density, Cojoba rufescens and Astronium graveolens, had relatively low C, low dry-season Ψ(stem), and intermediate seasonal change in water released. Thus, at least three, distinct stored-water-use strategies were observed. Additionally, bark relative water content (RWC) decreased along with Ψ(stem) during the dry season while xylem RWC did not change, suggesting that bark-stored water buffers Ψ(stem) seasonally. Together these results suggest that seasonal use of stored water and change in Ψ(stem) are associated with functional groups that are characterized by combinations of deciduousness and stem density.

  4. Assessing the thermal dissipation sap flux density method for monitoring cold season water transport in seasonally snow-covered forests.

    Science.gov (United States)

    Chan, Allison M; Bowling, David R; Phillips, Nathan

    2017-07-01

    Productivity of conifers in seasonally snow-covered forests is high before and during snowmelt when environmental conditions are optimal for photosynthesis. Climate change is altering the timing of spring in many locations, and changes in the date of transition from winter dormancy can have large impacts on annual productivity. Sap flow methods provide a promising approach to monitor tree activity during the cold season and the winter-spring and fall-winter transitions. Although sap flow techniques have been widely used, cold season results are generally not reported. Here we examine the feasibility of using the Granier thermal dissipation (TD) sap flux density method to monitor transpiration and dormancy of evergreen conifers during the cold season. We conducted a laboratory experiment which demonstrated that the TD method reliably detects xylem water transport (when it occurs) both at near freezing temperature and at low flow rate, and that the sensors can withstand repeated freeze-thaw events. However, the dependence between sensor output and water transport rate in these experiments differed from the established TD relation. In field experiments, sensors installed in two Abies forests lasted through two winters and a summer with low failure. The baseline (no-flow) sensor output varied considerably with temperature during the cold season, and a new baseline algorithm was developed to accommodate this variation. The Abies forests differed in elevation (2070 and 2620 m), and there was a clear difference in timing of initiation and cessation of transpiration between them. We conclude that the TD method can be reliably used to examine water transport during cold periods with associated low flow conditions. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  5. Decreasing but still significant facilitation effect of cold-season macrophytes on wetlands purification function during cold winter

    Science.gov (United States)

    Zou, Xiangxu; Zhang, Hui; Zuo, Jie; Wang, Penghe; Zhao, Dehua; An, Shuqing

    2016-06-01

    To identify the facilitation effect of a cool-season aquatic macrophyte (FEam) for use in effluent purification via constructed floating wetlands (CFWs) and to determine the possible pathways used during a winter period with an average temperature of less than 5 °C, pilot-scale CFWs were planted with the cold-season macrophyte Oenanthe clecumbens and were operated as batch systems. Although some leaves withered, the roots retained relatively high levels of activity during the winter, which had average air and water temperatures of 3.63 and 5.04 °C, respectively. The N and P removal efficiencies in CFWs decreased significantly in winter relative to those in late autumn. The presence of cool-season plants resulted in significant improvements in N and P removal, with a FEam of 15.23-25.86% in winter. Microbial N removal accounted for 71.57% of the total N removed in winter, and the decrease in plant uptake was the dominant factor in the wintertime decrease in N removal relative to that in late autumn. These results demonstrate the importance of cold-season plants in CFWs for the treatment of secondary effluent during cold winters.

  6. Decreasing but still significant facilitation effect of cold-season macrophytes on wetlands purification function during cold winter.

    Science.gov (United States)

    Zou, Xiangxu; Zhang, Hui; Zuo, Jie; Wang, Penghe; Zhao, Dehua; An, Shuqing

    2016-06-01

    To identify the facilitation effect of a cool-season aquatic macrophyte (FEam) for use in effluent purification via constructed floating wetlands (CFWs) and to determine the possible pathways used during a winter period with an average temperature of less than 5 °C, pilot-scale CFWs were planted with the cold-season macrophyte Oenanthe clecumbens and were operated as batch systems. Although some leaves withered, the roots retained relatively high levels of activity during the winter, which had average air and water temperatures of 3.63 and 5.04 °C, respectively. The N and P removal efficiencies in CFWs decreased significantly in winter relative to those in late autumn. The presence of cool-season plants resulted in significant improvements in N and P removal, with a FEam of 15.23-25.86% in winter. Microbial N removal accounted for 71.57% of the total N removed in winter, and the decrease in plant uptake was the dominant factor in the wintertime decrease in N removal relative to that in late autumn. These results demonstrate the importance of cold-season plants in CFWs for the treatment of secondary effluent during cold winters.

  7. Spent nuclear fuel project cold vacuum drying facility process water conditioning system design description

    Energy Technology Data Exchange (ETDEWEB)

    IRWIN, J.J.

    1998-11-30

    This document provides the System Design Description (SDD) for the Cold Vacuum Drying Facility (CVDF) Process Water Conditioning (PWC) System. The SDD was developed in conjunction with HNF-SD-SNF-SAR-002, Safety Analysis Report for the Cold Vacuum Drying Facility, Phase 2, Supporting Installation of Processing Systems (Garvin 1998), the HNF-SD-SNF-DRD-O02, 1998, Cold Vacuum Drying Facility Design Requirements, and the CVDF Design Summary Report. The SDD contains general descriptions of the PWC equipment, the system functions, requirements and interfaces. The SDD provides references for design and fabrication details, operation sequences and maintenance. This SDD has been developed for the SNFP Operations Organization and shall be updated, expanded, and revised in accordance with future design, construction and startup phases of the CVDF until the CVDF final ORR is approved.

  8. Spent Nuclear Fuel (SNF) Project Cold Vacuum Drying (CVD) Facility Operations Manual

    Energy Technology Data Exchange (ETDEWEB)

    IRWIN, J.J.

    2000-02-03

    This document provides the Operations Manual for the Cold Vacuum Drying Facility (CVDF). The Manual was developed in conjunction with HNF-SD-SNF-SAR-002, Safety Analysis Report for the Cold Vacuum Drying Facility, Phase 2, Supporting Installation of the Processing Systems (Garvin 1998) and, the HNF-SD-SNF-DRD-002, 1997, Cold Vacuum Drying Facility Design Requirements, Rev. 3a. The Operations Manual contains general descriptions of all the process, safety and facility systems in the CVDF, a general CVD operations sequence, and has been developed for the spent nuclear fuel project (SNFP) Operations Organization and shall be updated, expanded, and revised in accordance with future design, construction and startup phases of the CVDF until the CVDF final ORR is approved.

  9. Spent Nuclear Fuel (SNF) Cold Vacuum Drying (CVD) Facility Operations Manual

    Energy Technology Data Exchange (ETDEWEB)

    IRWIN, J.J.

    1999-07-02

    This document provides the Operations Manual for the Cold Vacuum Drying Facility (CVDF). The Manual was developed in conjunction with HNF-553, Spent Nuclear Fuel Project Final Safety Analysis Report Annex B--Cold Vacuum Drying Facility. The HNF-SD-SNF-DRD-002, 1999, Cold Vacuum Drying Facility Design Requirements, Rev. 4, and the CVDF Final Design Report. The Operations Manual contains general descriptions of all the process, safety and facility systems in the CVDF, a general CVD operations sequence and references to the CVDF System Design Descriptions (SDDs). This manual has been developed for the SNFP Operations Organization and shall be updated, expanded, and revised in accordance with future design, construction and startup phases of the CVDF until the CVDF final ORR is approved.

  10. Spent nuclear fuel project cold vacuum drying facility vacuum and purge system design description

    Energy Technology Data Exchange (ETDEWEB)

    IRWIN, J.J.

    1998-11-30

    This document provides the System Design Description (SDD) for the Cold Vacuum Drying Facility (CVDF) Vacuum and Purge System (VPS) . The SDD was developed in conjunction with HNF-SD-SNF-SAR-O02, Safety Analysis Report for the Cold Vacuum Drying Facility, Phase 2, Supporting Installation of Processing Systems (Garvin 1998), The HNF-SD-SNF-DRD-002, 1998, Cold Vacuum Drying Facility Design Requirements, and the CVDF Design Summary Report. The SDD contains general descriptions of the VPS equipment, the system functions, requirements and interfaces. The SDD provides references for design and fabrication details, operation sequences and maintenance. This SDD has been developed for the SNFP Operations Organization and shall be updated, expanded, and revised in accordance with future design, construction and startup phases of the CVDF until the CVDF final ORR is approved.

  11. Spent nuclear fuel project cold vacuum drying facility supporting data and calculation database

    Energy Technology Data Exchange (ETDEWEB)

    IRWIN, J.J.

    1999-02-26

    This document provides a database of supporting calculations for the Cold Vacuum Drying Facility (CVDF). The database was developed in conjunction with HNF-SD-SNF-SAR-002, ''Safety Analysis Report for the Cold Vacuum Drying Facility'', Phase 2, ''Supporting Installation of Processing Systems'' (Garvin 1998). The HNF-SD-SNF-DRD-002, 1997, ''Cold Vacuum Drying Facility Design Requirements'', Rev. 2, and the CVDF Summary Design Report. The database contains calculation report entries for all process, safety and facility systems in the CVDF, a general CVD operations sequence and the CVDF System Design Descriptions (SDDs). This database has been developed for the SNFP CVDF Engineering Organization and shall be updated, expanded, and revised in accordance with future design, construction and startup phases of the CVDF until the CVDF final ORR is approved.

  12. Relationship soil-water-plant after the dry season in dry Mediterranean areas

    Science.gov (United States)

    Hueso-González, P.; Jiménez-Donaire, V.; Ruiz-Sinoga, J. D.

    2012-04-01

    Preliminary studies have determined the existence of a pluviometric gradient around Mediterranean system, which varies from 240 to 1 100 mm mean annual rainfall. This gradient has an incidence in the physical, chemical and hydrological properties in soils with the same litology. Empiric results conclude that humid eco-geomorphological systems are controlled by biotic processes, whereas in arid eco-geomorphological systems, are abiotic factors which have more importance in soil degradation processes. The study area of the present work is located in Málaga (Andalusia, Spain), in the southern part of the Natural Park "Sierra Tejeda, Almijara y Alhama". There, the mean annual temperature is around 18 °C and the mean rainfall is 650 mm. Predominant vegetation corresponds to the termomediterranean serie Smilaci Mauritanicae-Querceto Rotundifoliae Sigmetum, typical of basic soils. The aim of this study is to analyse the immediate hydrological response of the soil under different vegetation covers, through the analysis of certain properties, all this, under subhumid ombrotipe. A random choice of ten representative plants has been done. These plants, with different sizes, were located in the same Southern slope. The soil samples were taken right beside the plant log, and also within a distance of 0.4 to 1 metre from them, depending on the plant size. The sampling was carried out between the end of the dry season and the beginning of the wet one, after a 20% of the mean annual rainfall had rained. The physical, chemical and hydrological analyzes -both in the field and the laboratory- were: exchange-base, total carbon, cation exchange capacity, soil infiltration capacity, salt content, hydrophobia, organic matter, soil organic carbon, total nitrogen, wetting profile in bared soil, wetting profile under vegetation cover (shrubland), and p.H. Literature reveals that rainfall affects significantly the edafogenetic factors, regarding the pluviometric gradient level. In the

  13. Hyperventilation with cold versus dry air in 2- to 5-year-old children with asthma

    DEFF Research Database (Denmark)

    Nielsen, Kim G; Bisgaard, Hans

    2005-01-01

    -step protocols: dry air challenge (DACh) performed as 6 minutes of eucapnic hyperventilation with dry room-temperature air and CACh as 4 minutes of hyperventilation. Response was measured as specific airway resistance by whole-body plethysmography and expressed as change from baseline in numbers of within......UNLABELLED: Cold air challenge (CACh) has been shown to discriminate between children with asthma and healthy young children. Hyperventilation with dry room-temperature air is a simplified alternative. We compared responsiveness in young children with asthma between two standardized, single......-subject SDs (SDw). The challenge sequence was randomly assigned. A comparator challenge was performed 1 hour later if the first challenge gave a change of 3 SDw or more. Forty 2- to 5-year-old children with asthma were included. Responsiveness to cold versus dry air showed significant, but weak, correlation...

  14. Effects of shifting seasonal rainfall patterns on net primary productivity and carbon storage in tropical seasonally dry ecosystems

    Science.gov (United States)

    Rohr, T.; Manzoni, S.; Feng, X.; Menezes, R.; Porporato, A. M.

    2013-12-01

    Although seasonally dry ecosystems (SDEs), identified by prolonged drought followed by a short, but intense, rainy season, cover large regions of the tropics, their biogeochemical response to seasonal rainfall and soil carbon (C) sequestration potential are not well characterized. Both productivity and soil respiration are positively affected by seasonal soil moisture availability, creating a delicate balance between C deposition through litterfall and C losses through heterotrophic respiration. As climate change projections for the tropics predict decreased annual rainfall and increased dry season length, it is critical to understand how variations in seasonal rainfall distributions control this balance. To address this question, we develop a minimal model linking the seasonal behavior of the ensemble soil moisture, plant productivity, the related soil C inputs through litterfall, and soil C dynamics. The model is parameterized for a case study from a drought-deciduous caatinga ecosystem in northeastern Brazil. Results indicate that when altering the seasonal rainfall patterns for a fixed annual rainfall, both plant productivity and soil C sequestration potential are largely, and nonlinearly, dependent on wet season duration. Moreover, total annual rainfall plays a dominant role in describing this relationship, leading at times to the emergence of distinct optima in both primary production and C sequestration. Examining these results in the context of climate-driven changes to wet season duration and mean annual precipitation indicate that the initial hydroclimatic regime of a particular ecosystem is an important factor to predict both the magnitude and direction of the effects of shifting seasonal distributions on productivity and C storage. Although highly productive ecosystems will likely experience declining C storage with predicted climate shifts, those currently operating well below peak production can potentially see improved C stocks with the onset of

  15. Cold vacuum drying proof of performance (first article testing) test results

    Energy Technology Data Exchange (ETDEWEB)

    MCCRACKEN, K.J.

    1999-06-23

    This report presents and details the test results of the first of a kind process referred to as Cold Vacuum Drying (CVD). The test results are compiled from several months of testing of the first process equipment skid and ancillary components to de-water and dry Multi-Canister Overpacks (MCO) filled with Spent Nuclear Fuel (SNF). The tests results provide design verifications, equipment validations, model validation data, and establish process parameters.

  16. Phytoplankton dynamics of a tropical river: A dry and rainy season ...

    African Journals Online (AJOL)

    ... dynamics of a tropical river: A dry and rainy season comparison. ... Qualitative phytoplankton samples were collected by towing 55 ìm mesh plankton net while quantitative samples were obtained by sedimenting a known volume of water ...

  17. Dry season distribution of hydroids in a small tropical estuary, Pernambuco, Brazil

    NARCIS (Netherlands)

    Calder, D.R.; Maÿal, E.M.

    1998-01-01

    Hydroid distribution patterns along a horizontal ecocline in the Rio Formoso/Rio Ariquindá/Rio Porto Alegre system, a small and seasonally poikilohaline estuary on the tropical northeast coast of Brazil, were investigated. Collecting was undertaken during the dry season, in November 1993, by diving

  18. Penicillium salamii, a new species occurring during seasoning of dry-cured meat

    NARCIS (Netherlands)

    Perrone, Giancarlo; Samson, Robert A; Frisvad, Jens C; Susca, Antonia; Gunde-Cimerman, Nina; Epifani, Filomena; Houbraken, Jos

    2015-01-01

    Fungi have an important role in the production of dry-cured meat products, especially during the seasoning period. In general, both industrially and handmade salami are quickly colonized by a composite mycobiota during seasoning, often with a strong predominance of Penicillium species. These species

  19. Dry season distribution of hydroids in a small tropical estuary, Pernambuco, Brazil

    NARCIS (Netherlands)

    Calder, D.R.; Maÿal, E.M.

    1998-01-01

    Hydroid distribution patterns along a horizontal ecocline in the Rio Formoso/Rio Ariquindá/Rio Porto Alegre system, a small and seasonally poikilohaline estuary on the tropical northeast coast of Brazil, were investigated. Collecting was undertaken during the dry season, in November 1993, by diving

  20. Spectroscopic analysis of seasonal changes in live fuel moisture content and leaf dry mass

    Science.gov (United States)

    Yi Qi; Philip E. Dennison; W. Matt Jolly; Rachael C. Kropp; Simon C. Brewer

    2014-01-01

    Live fuel moisture content (LFMC), the ratio of water mass to dry mass contained in live plant material, is an important fuel property for determining fire danger and for modeling fire behavior. Remote sensing estimation of LFMC often relies on an assumption of changing water and stable dry mass over time. Fundamental understanding of seasonal variation in plant water...

  1. Dry Season Effect on Live Weight and some Body Dimensions of Working Donkeys in the Sudano-sahel Region of Cameroon

    Directory of Open Access Journals (Sweden)

    Ebangi, AL.

    2005-01-01

    Full Text Available Live weight (LW, heart girth (HG, trunk length (TL, body length (BL and height-at-withers (HW of 135 working donkeys, aged between two and 15 years, were monitored during the dry season of 1996 and 1997. This was to determine period(s of the dry season when feed supplementation and/or health care should be reinforced in preparation of high work demands during the rainy season. Variations in LW, HG, TL, BL, HW, HG:HW and TL:HW from start of the dry season to the start of the rainy season were highly significant (P< 0.001. Correlations between live weight and the other measures were positive and highly significant (P< 0.0001. Males showed weight gains between start of the cold-dry-season (CDS and start of the hot-dryseason (HDS. Weight gains in castrates were between start of the CDS and end of the HDS (April. Female donkeys maintained weight gains through out the dry season. Consequently, supplementation of castrates and males at the beginning (January and end (April of the HDS as to reinforce and maintain significant weight gains for maximize draught energy potential for rainy season work demands, is necessary. Where the female donkey express weight gain but poor bodied there will be need for supplementation in order to booster and enhance endurance. Also, estimates of HG, TL, BL, HW, HG:HW and TL:HW may be useful indicators for the selection of working donkeys as to optimize draft capacity and endurance for rainy season work demands.

  2. Reproductive Phenology of a Seasonally-Dry Dipterocarp Forest in Southern Thailand

    Science.gov (United States)

    Kurten, E.; Bunyavejchewin, S.; Davies, S. J.

    2015-12-01

    Our understanding of the proximate and ultimate factors that shape reproductive phenology in dipterocarp forests comes exclusively from studies of everwet, general flowering forests. This study, for the first time, examines the reproductive phenology of a dipterocarp-dominated forest in a seasonally-dry region in Southeast Asia. We monitored flowering and fruiting monthly for 1344 trees (>300 spp.) in a seasonally-dry forest in Khao Chong, Thailand from 2001-2009, and assessed frequency, duration, seasonality, and synchrony of reproduction. Reproductive phenology of the Khao Chong forest was more similar to tropical forests in other seasonally-dry parts of the tropics than it was to dipterocarp forests in everwet regions of Southeast Asia, despite being more phylogenetically similar to the latter. The Khao Chong forest exhibited annual reproduction, with peak flowering occurring at the end of the dry season, and peak fruiting occurring early in the wet season. The majority of species and individuals also reproduced annually, including some species that are known to be "general flowering" in everwet climates. Short periods of drought appeared to be the cue that initiated flowering in early flowering species, while species flowering later in the dry season may have responded to either drought or low temperature. Over the eight years of our study, we observed a decline in the proportion of individuals reproducing each season. This decline appeared to be associated with a shorter dry season due to a later onset of continuous drought, suggesting that changing climate in the region may have significant impacts on plant reproduction and recruitment.

  3. Relationship between seasonal cold acclimatization and mtDNA haplogroup in Japanese

    Directory of Open Access Journals (Sweden)

    Nishimura Takayuki

    2012-08-01

    Full Text Available Abstract Background The purpose of this study was to elucidate the interaction between mtDNA haplogroup and seasonal variation that contributes to cold adaptation. Methods There were 15 subjects (seven haplotype D subjects and eight haplotype non-D subjects. In summer and winter, the subjects were placed in an environment where the ambient temperature dropped from 27 °C to 10 °C in 30 minutes. After that, they were exposed to cold for 60 minutes. Results In summer, the decrease in rectal temperature and increase in oxygen consumption was smaller and cold tolerance was higher in the haplotype non-D group than in the haplotype D group. In winter, no significant differences were seen in rectal temperature or oxygen consumption, but the respiratory exchange ratio decreased in the haplotype D group. Conclusions The results of the present study suggest that haplogroup D subjects are a group that changes energy metabolism more, and there appears to be a relationship between differences in cold adaptability and mtDNA polymorphism within the population. Moreover, group differences in cold adaptability seen in summer may decrease in winter due to supplementation by seasonal cold acclimatization.

  4. Population dynamic of the swallowtail butterfly, Papilio polytes (Lepidoptera: Papilionidae in dry and wet seasons

    Directory of Open Access Journals (Sweden)

    SUWARNO

    2010-01-01

    Full Text Available Suwarno (2010 Population dynamic of the swallowtail butterfly, Papilio polytes (Lepidoptera: Papilionidae in dry and wet seasons. Biodiversitas 11: 19-23. The population dynamic of Papilio polytes L. (Lepidoptera: Papilionidae in dry and wet seasons was investigated in the citrus orchard in Tasek Gelugor, Pulau Pinang, Malaysia. Population of immature stages of P. polytes was observed alternate day from January to March 2006 (dry season, DS, from April to July 2006 (secondary wet season, SWS, and from October to December 2006 (primary wet season, PWS. The population dynamics of the immature stages of P. polytes varied between seasons. The immature stages of P. polytes are more abundance and significantly different in the PWS than those of the DS and the SWS. The larval densities in all seasons decreased with progressive development of the instar stages. Predators and parasitoids are the main factor in regulating the population abundance of immature stages of P. polytes. There were positive correlations between the abundance of immature stages of P. polytes and their natural enemies abundance in each season. Ooencyrtus papilioni Ashmead (Hymenoptera: Encyrtidae is the most egg parasitoid. Oxyopes quadrifasciatus L. Koch. and O. elegans L. Koch. (Araneae: Oxyopidae are the main predators in the young larvae, meanwhile Sycanus dichotomus Stal. (Heteroptera: Reduviidae, Calotes versicolor Fitzinger (Squamata: Agamidae, birds and praying mantis attacked the older larvae.

  5. Influence of dry-season vegetation variability on Sahelian dust during 2002-2015

    Science.gov (United States)

    Kergoat, L.; Guichard, F.; Pierre, C.; Vassal, C.

    2017-05-01

    The drivers of dust emission interannual variability in North Africa, the largest dust source on Earth, are still debated. Early studies outlined the role of previous-season rainfall and vegetation growth, while some recent studies emphasize the role of wind variability. Here we use a newly developed estimation of dry-season nonphotosynthetic vegetation cover in the Sahel based on Moderate Resolution Imaging Spectroradiometer (MODIS) short-wave infrared bands over the 2002-2015 period. The vegetation growth anomalies caused by variability of rainfall in June-September translate to anomalies of dry vegetation cover that persist throughout the dry season until May. These vegetation anomalies explain 43% (50%) of the year-to-year variance in Sahelian-mean dry-season aerosol optical depth (AOD) as derived from MODIS Deep Blue (Sun photometers). Similar explained variance is found with 10 m wind speed and dust uplift potential. The central Sahel proves more important than the western Sahel for dry-season AOD variability.

  6. Increased Frequency of Large Blowdown Formation in Years With Hotter Dry Seasons in the Northwestern Amazon

    Science.gov (United States)

    Rifai, S. W.; Anderson, L. O.; Bohlman, S.

    2015-12-01

    Blowdowns, which are large tree mortality events caused by downbursts, create large pulses of carbon emissions in the short term and alter successional dynamics and species composition of forests, thus affecting long term biogeochemical cycling of tropical forests. Changing climate, especially increasing temperatures and frequency of extreme climate events, may cause changes in the frequency of blowdowns, but there has been little spatiotemporal analysis to associate the interannual variation in the frequency of blowdowns with annual climate parameters. We mapped blowdowns greater than 25 ha using a time series of Landsat images from 1984-2012 in the northwestern Amazon to estimate the annual size distribution of these blowdowns. The difference in forest area affected by blowdowns between the years with the highest and lowest blowdown activity were on the order of 10 - 30 times greater depending on location. Spatially, we found the probability of large blowdowns to be higher in regions with higher annual rainfall. Temporally, we found a positive correlation between the probability of large blowdown events and maximum dry season air temperature (R2 = 0.1-0.46). Mean and maximum blowdown size also increased with maximum dry season air temperature. The strength of these relationships varied between scene locations which may be related to cloud cover obscuring the land surface in the satellite images, or biophysical characteristics of the sites. Potentially, elevated dry season temperatures during the transition from the dry season to the wet season (October - December) may exacerbate atmospheric instabilities, which promote downburst occurrences. Most global circulation models predict dry season air temperatures to increase 2-5 ℃ in the northwestern Amazon by 2050. Should the blowdown disturbance regime continue increasing with elevated dry season temperatures, the northwestern Amazon is likely to experience more catastrophic tree mortality events which has direct

  7. Cold Vacuum Drying Facility Crane and Hoist System Design Description (SYS 14)

    Energy Technology Data Exchange (ETDEWEB)

    TRAN, Y.S.

    2000-06-07

    This system design description (SDD) is for the Cold Vacuum Drying (CVD) Facility overhead crane and hoist system. The overhead crane and hoist system is a general service system. It is located in the process bays of the CVD Facility, supports the processes required to drain the water and dry the spent nuclear fuel (SNF) contained in the multi-canister overpacks (MCOs) after they have been removed from the K-Basins. The location of the system in the process bay is shown.

  8. Multiple supplements for beef heifers on pasture in dry season

    Directory of Open Access Journals (Sweden)

    Renata Pereira da Silva-Marques

    2015-02-01

    Full Text Available The objective was to evaluate levels of multiple supplement for beef heifers in restricted grazing on average daily gain (ADG, economic analysis and intakes of total dry matter (TDMI, forage dry matter (FDMI, crude protein (CPI and total digestible nutrients (TDNI. For evaluation of performance and economic analysis, twenty Nellore heifers (328.45 kg were used. The following supplements were evaluated as fed to the animals: control (mineral supplement and supplementation levels of 2, 4 and 6 kg/animal/day, composing the following percentages of average body weight (ABW: 0.55, 1.11 and 1.66%, respectively. To evaluate the nutrient intake, additional five Nellore heifers with 344 kg, were used, which were submitted to same supplements previously mentioned, in addition to the level of 2.22% of ABW (8 kg/animal/day. Average daily gain showed quadratic behavior; TDMI, CPI and TDNI had increasing linear behavior; and FDMI showed decreasing linear behavior in function of the supplementation levels. The strategy of supplying 0.55, 1.11 and 1.66% of the ABW to heifers on restricted grazing provides additional weight gains of 608, 762 and 943 g/day, respectively, which are effective in promoting similar productive and economic performance to those obtained in grazing systems in the rainy period.

  9. Cold Vacuum Drying facility deionized water system design description (SYS 25)

    Energy Technology Data Exchange (ETDEWEB)

    PITKOFF, C.C.

    1999-07-02

    This document describes the Cold Vacuum Drying Facility (CVDF) de-ionized water system. The de-ionized water system is used to provide clean, conditioned water, free from contaminants, chlorides and iron for the CVD Facility. Potable water is supplied to the deionized water system, isolated by a backflow prevention device. After the de-ionization process is complete, via a packaged de-ionization unit, de-ionized water is supplied to the process deionization unit.

  10. Cold Vacuum Drying facility civil structural system design description (SYS 06)

    Energy Technology Data Exchange (ETDEWEB)

    PITKOFF, C.C.

    1999-07-06

    This document describes the Cold Vacuum Drying (CVD) Facility civil - structural system. This system consists of the facility structure, including the administrative and process areas. The system's primary purpose is to provide for a facility to house the CVD process and personnel and to provide a tertiary level of containment. The document provides a description of the facility and demonstrates how the design meets the various requirements imposed by the safety analysis report and the design requirements document.

  11. A comparison of dry and wet season aerosol number fluxes over the Amazon rain forest

    Directory of Open Access Journals (Sweden)

    L. Ahlm

    2010-03-01

    Full Text Available Vertical number fluxes of aerosol particles and vertical fluxes of CO2 were measured with the eddy covariance method at the top of a 53 m high tower in the Amazon rain forest as part of the LBA (The Large Scale Biosphere Atmosphere Experiment in Amazonia experiment. The observed aerosol number fluxes included particles with sizes down to 10 nm in diameter. The measurements were carried out during the wet and dry season in 2008. In this study focus is on the dry season aerosol fluxes, with significant influence from biomass burning, and these are compared with aerosol fluxes measured during the wet season.

    Net particle deposition fluxes dominated in daytime in both seasons and the deposition flux was considerably larger in the dry season due to the much higher dry season particle concentration. The particle transfer velocity increased linearly with increasing friction velocity in both seasons. The difference in transfer velocity between the two seasons was small, indicating that the seasonal change in aerosol number size distribution is not enough for causing any significant change in deposition velocity. In general, particle transfer velocities in this study are low compared to studies over boreal forests. The reasons are probably the high percentage of accumulation mode particles and the low percentage of nucleation mode particles in the Amazon boundary layer, both in the dry and wet season, and low wind speeds in the tropics compared to the midlatitudes.

    In the dry season, nocturnal particle fluxes behaved very similar to the nocturnal CO2 fluxes. Throughout the night, the measured particle flux at the top of the tower was close to zero, but early in the morning there was an upward particle flux peak that is not likely a result of entrainment or local pollution. It is possible that these morning upward particle fluxes are associated with emission of primary biogenic particles from the rain forest

  12. Identification of metals into fine particles (PM{sub 2.5}) during the dry cold season in the Toluca City; Identificacion de metales en particulas finas (PM{sub 2.5}) durante la epoca seca-fria en la ciudad de Toluca

    Energy Technology Data Exchange (ETDEWEB)

    Martinez P, A. A. [Universidad Autonoma del Estado de Mexico, Facultad de Quimica, Paseo Tollocan esquina Paseo Colon s/n, Toluca 50180, Estado de Mexico (Mexico); Aldape U, F. [ININ, Carretera Mexico-Toluca s/n, Ocoyoacac 52750, Estado de Mexico (Mexico)

    2008-07-01

    To know the elemental content of fine particles PM{sub 2.5} that can affect people in the Toluca City, such as metals and another, it was made a campaign collection of fine particles during dry-cold ( November 2006-March 2007). The aerosol samples were collected on Teflon filters with an equipment BGI model PQ200 mark authorized by the Environment Protection Agency (EPA), every other day with a time resolution of 24 h. The determination of the elemental composition of the samples was performed by means of the technique Particle Induced X-Ray Emission (PIXE). The results of the analysis showed consistently 13 elements S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, as, throughout the collection period. We calculated the enrich factor that separates the elements of the natural component of the anthropogenic component. The correlation matrix shows the pairs of elements that are contained in the same air mass as Vanadium and Nickel. From the results it is concluded that the sources that gave rise to these particles are the burning of fossil fuels in motor vehicles, lubricants, additives and burning tires wear of automotive vehicles, besides the products used in agricultural activities. (Author)

  13. Impact of Long Dry Season on Bean Characteristics of Robusta Coffee (Coffea canephora

    Directory of Open Access Journals (Sweden)

    Ucu Sumirat

    2008-07-01

    Full Text Available Bean characteristics in Robusta coffee (Coffea canephora should be taken into considerations in coffee breeding. Beside genetic factor, environment has been known as an important factor in the formation and change of composition of bean characteristics. This research aimed to find out the effect of long dry season on changes of bean characteristics. The population observed consisted of 277 genotypes originated from reciprocal crossings of three parental namely BP 409, BP 961 and Q 121. Observation was conducted in Kaliwining Experimental Garden of ICCRI in Jember, East Java during two years with different drought intensity i.e. 2005—2006 and 2006—2007 production years. The result showed that long dry season decreased the range value of population of normal beans, pea beans and triage beans, and followed by decreasing in the mean value except for normal beans. Long dry season also influence the change of value range of empty bean to higher proportion, and followed by increasing in the mean value. Distribution pattern of normal beans tend in to remain at high proportion, in contrast to those of pea and triage beans. In other side, long dry season tended to change distribution pattern of empty beans to at high proportion. Correlation analysis among beans characteristics showed that normal beans had negative correlations with pea beans and empty beans. Pea beans had a positive correlation with empty beans. Long dry season decreased proportion of pea bean and triage bean, in contrast to those of empty beans. Increasing proportion of empty bean was caused by failure of growth to normal bean under stress condition. Key words : Coffee canephora, bean characteristics, long dry season, variation, correlation, composition.

  14. The Dry Season Shuffle: Gorges Provide Refugia for Animal Communities in Tropical Savannah Ecosystems.

    Directory of Open Access Journals (Sweden)

    J Sean Doody

    Full Text Available In the wet-dry tropics, animal species face the major challenges of acquiring food, water or shelter during an extended dry season. Although large and conspicuous animals such as ungulates and waterfowl migrate to wetter areas during this time, little is known of how smaller and more cryptic animal species with less mobility meet these challenges. We fenced off the entire entrance of a gorge in the Australian tropical savanna, offering the unique opportunity to determine the composition and seasonal movement patterns of the small vertebrate community. The 1.7 km-long fence was converted to a trapline that was deployed for 18-21 days during the early dry season in each of two years, and paired traps on both sides of the fence allowed us to detect the direction of animal movements. We predicted that semi-aquatic species (e.g., frogs and turtles would move upstream into the wetter gorge during the dry season, while more terrestrial species (e.g., lizards, snakes, mammals would not. The trapline captured 1590 individual vertebrates comprising 60 species. There was a significant bias for captures on the outside of the fence compared to the inside for all species combined (outside/inside = 5.2, CI = 3.7-7.2, for all vertebrate classes, and for specific taxonomic groups. The opposite bias (inside/outside = 7.3, N= 25 for turtles during the early wet season suggested return migration heading into the wet season. Our study revealed that the small vertebrate community uses the gorge as a dry season refuge. The generality of this unreplicated finding could be tested by extending this type of survey to tropical savannahs worldwide. A better understanding of how small animals use the landscape is needed to reveal the size of buffer zones around wetlands required to protect both semi-aquatic and terrestrial fauna in gorges in tropical savannah woodland, and thus in ecosystems in general.

  15. Effect of rainfall seasonality on carbon storage in tropical dry ecosystems

    Science.gov (United States)

    Rohr, Tyler; Manzoni, Stefano; Feng, Xue; Menezes, Rômulo S. C.; Porporato, Amilcare

    2013-07-01

    seasonally dry conditions are typical of large areas of the tropics, their biogeochemical responses to seasonal rainfall and soil carbon (C) sequestration potential are not well characterized. Seasonal moisture availability positively affects both productivity and soil respiration, resulting in a delicate balance between C deposition as litterfall and C loss through heterotrophic respiration. To understand how rainfall seasonality (i.e., duration of the wet season and rainfall distribution) affects this balance and to provide estimates of long-term C sequestration, we develop a minimal model linking the seasonal behavior of the ensemble soil moisture, plant productivity, related C inputs through litterfall, and soil C dynamics. A drought-deciduous caatinga ecosystem in northeastern Brazil is used as a case study to parameterize the model. When extended to different patterns of rainfall seasonality, the results indicate that for fixed annual rainfall, both plant productivity and soil C sequestration potential are largely, and nonlinearly, dependent on wet season duration. Moreover, total annual rainfall is a critical driver of this relationship, leading at times to distinct optima in both production and C storage. These theoretical predictions are discussed in the context of parameter uncertainties and possible changes in rainfall regimes in tropical dry ecosystems.

  16. Soil emissions of nitric oxide in a seasonally dry tropical forest of Mexico

    Science.gov (United States)

    Davidson, Eric A.; Vitousek, Peter M.; Riley, Ralph; Matson, Pamela A.; Garcia-Mendez, Georgina; Maass, J. M.

    1991-01-01

    Soil emissions of NO were measured at the Chamela Biological Station, Mexico, using soil covers and a field apparatus of NO detection based on CrO3 conversion of NO to NO2 and detection of NO2 by chemiluminescence with Luminol. Mean NO fluxes from forest soils ranged from 0.14 to 0.52 ng NO-N/sq cm/hr during the dry season and from 0.73 to 1.27 ng NO-N/sq cm/hr during the wet season. A fertilized floodplain pasture exhibited higher fluxes, but an unfertilized upland pasture, which represents the fastest growing land use in the region, had flux rates similar to the forest sites. Wetting experiments at the end of the dry season caused large pulses of NO flux, equaling 10 percent to 20 percent of the estimated annual NO emissions of 0.5-1.0 kg N/ha from the forest sites. Absence of a forest canopy during the dry season and the first wet season rain probably results in substantial NO(x) export from the forest system that may be important to regional atmospheric chemical processes. Wetting experiments during the wet season and a natural rain event had little or no stimulatory effect on NO flux rates.

  17. Observed changes in extreme wet and dry spells during the South Asian summer monsoon season

    Science.gov (United States)

    Singh, Deepti; Tsiang, Michael; Rajaratnam, Bala; Diffenbaugh, Noah S.

    2014-06-01

    The South Asian summer monsoon directly affects the lives of more than 1/6th of the world's population. There is substantial variability within the monsoon season, including fluctuations between periods of heavy rainfall (wet spells) and low rainfall (dry spells). These fluctuations can cause extreme wet and dry regional conditions that adversely impact agricultural yields, water resources, infrastructure and human systems. Through a comprehensive statistical analysis of precipitation observations (1951-2011), we show that statistically significant decreases in peak-season precipitation over the core-monsoon region have co-occurred with statistically significant increases in daily-scale precipitation variability. Further, we find statistically significant increases in the frequency of dry spells and intensity of wet spells, and statistically significant decreases in the intensity of dry spells. These changes in extreme wet and dry spell characteristics are supported by increases in convective available potential energy and low-level moisture convergence, along with changes to the large-scale circulation aloft in the atmosphere. The observed changes in wet and dry extremes during the monsoon season are relevant for managing climate-related risks, with particular relevance for water resources, agriculture, disaster preparedness and infrastructure planning.

  18. The perennial clock is an essential timer for seasonal growth events and cold hardiness.

    Science.gov (United States)

    Johansson, Mikael; Ibáñez, Cristian; Takata, Naoki; Eriksson, Maria E

    2014-01-01

    Over the last several decades, changes in global temperatures have led to changes in local environments affecting the growth conditions for many species. This is a trend that makes it even more important to understand how plants respond to local variations and seasonal changes in climate. To detect daily and seasonal changes as well as acute stress factors such as cold and drought, plants rely on a circadian clock. This chapter introduces the current knowledge and literature about the setup and function of the circadian clock in various tree and perennial species, with a focus on the Populus genus.

  19. Diurnal resting in brown lemurs in a dry deciduous forest, northwestern Madagascar: implications for seasonal thermoregulation.

    Science.gov (United States)

    Sato, Hiroki

    2012-07-01

    Decreased activity has been reported in both nocturnal and diurnal primates during the prolonged dry season in western Madagascar, and this has been interpreted as a reaction to the severe environment, with its food scarcity and/or thermal stress. Several day-active lemurs rest more as trees defoliate, although the reason for this is unclear. To understand the mechanism underpinning the diurnal resting of lemurs in seasonal deciduous forests, I observed common brown lemurs (Eulemur fulvus fulvus) for one year in Ankarafantsika National Park, northwestern Madagascar. In Ankarafantsika, despite high fruit availability during the dry season, brown lemurs are known to engage in diurnal resting. To examine the effects of thermal factors and defoliation on lemur inactivity, I recorded the activity of a troop at 1 min intervals, hourly ambient temperature, daily rainfall, and weather during observations (06:00-18:00). I quantified the amount of leaves biweekly for 680 trees. I tested correlations between percentages of resting time and each factor across hours during the day and across seasons. During the rainy season, resting time did not differ between sunny and cloudy days, and lemurs were active throughout the daytime. At the hourly level during the dry season, lemurs rested exclusively at midday, apparently at peak sunlight intensity rather than at peak ambient temperature. At seasonal level, percentages of total resting time from 08:00 to 16:00 were greater during dry season (81.9%) than during rainy season (62.6%), and percentages increased as ambient temperatures increased. Defoliation was related to seasonal decrease in weekly rainfall, which served as an index of water retained in the forest. Defoliation probably reflected aridification as well as the penetration of sunlight into the forest. Diurnal resting increased as both the amount of leaves and weekly rainfall decreased seasonally. These results suggest that heat stress under dry conditions may promote

  20. Effect of Dietary Types on Feed Intakes, Growth Performance and Economic Benefit in Tibetan sheep and Yaks on the Qinghai-Tibet Plateau during Cold Season

    Science.gov (United States)

    Xu, Shixiao; Hu, Linyong; Zhao, Na; Liu, Zhe; Ma, Li; Liu, Hongjin; Zhao, Xinquan

    2017-01-01

    Pastoralists on the Tibetan alpine rangeland suffered great economic loss in cold season, due to serious live-weight loss of domestic livestock under traditional grazing management. This study aimed to evaluate the effect of dietary types (crude protein levels) on feed intakes, growth performance and economic returns of local Tibetan sheep and yaks during cold season. Twenty-four yearling Tibetan sheep (25.29±3.95 kg LW) and twenty two-year-old yaks (100.62±4.55 kg LW) with familiar body conditions were randomly assigned to four groups, fed oats hay (OH), oats silage (OS), total mixed ration (TMR) and traditionally grazed on the local cool-season pasture (TG), respectively, over a 135-day experiment. Daily dry matter intake was determined; all animals were weighed at the beginning and every 15 days of the 135-day experiment. Then, the total live-weight gain, average daily live-weight gain, gain rate, feed efficiency and net economic benefit were calculated. Results indicated that feed and nutrient intakes (DMI, DMI/kg LW, DMI/kg LW0.75 and CPI) of TMR, OH and OS were higher than TG (P 0.05). Results indicated that TMR was a reasonable diet in promoting feed intakes, animal performance, feed efficiency and economic returns in domestic livestock, which should be considered by local herdsmen to increase their breeding profit during cold season. PMID:28056054

  1. Spent Nuclear Fuel (SNF) Project Cold Vacuum Drying (CVD) Facility Operations Manual

    Energy Technology Data Exchange (ETDEWEB)

    IRWIN, J.J.

    2000-11-18

    The mission of the Spent Nuclear Fuel (SNF) Project Cold Vacuum Drying Facility (CVDF) is to achieve the earliest possible removal of free water from Multi-Canister Overpacks (MCOs). The MCOs contain metallic uranium SNF that have been removed from the 100K Area fuel storage water basins (i.e., the K East and K West Basins) at the US. Department of Energy Hanford Site in Southeastern Washington state. Removal of free water is necessary to halt water-induced corrosion of exposed uranium surfaces and to allow the MCOs and their SNF payloads to be safely transported to the Hanford Site 200 East Area and stored within the SNF Project Canister Storage Building (CSB). The CVDF is located within a few hundred yards of the basins, southwest of the 165KW Power Control Building and the 105KW Reactor Building. The site area required for the facility and vehicle circulation is approximately 2 acres. Access and egress is provided by the main entrance to the 100K inner area using existing roadways. The CVDF will remove free. water from the MCOs to reduce the potential for continued fuel-water corrosion reactions. The cold vacuum drying process involves the draining of bulk water from the MCO and subsequent vacuum drying. The MCO will be evacuated to a pressure of 8 torr or less and backfilled with an inert gas (helium). The MCO will be sealed, leak tested, and then transported to the CSB within a sealed shipping cask. (The MCO remains within the same shipping Cask from the time it enters the basin to receive its SNF payload until it is removed from the Cask by the CSB MCO handling machine.) The CVDF subproject acquired the required process systems, supporting equipment, and facilities. The cold vacuum drying operations result in an MCO containing dried fuel that is prepared for shipment to the CSB by the Cask transportation system. The CVDF subproject also provides equipment to dispose of solid wastes generated by the cold vacuum drying process and transfer process water removed

  2. Seasonal variability of leaf area index and foliar nitrogen in contrasting dry-mesic tundras

    DEFF Research Database (Denmark)

    Campioli, Matteo; Michelsen, Anders; Lemeur, Raoul;

    2009-01-01

    Assimilation and exchange of carbon for arctic ecosystems depend strongly on leaf area index (LAI) and total foliar nitrogen (TFN). For dry-mesic tundras, the seasonality of these characteristics is unexplored. We addressed this knowledge gap by measuring variations of LAI and TFN at five...... contrasting subarctic heaths during the growing season 2007, from about 2 weeks after bud burst until about 2 weeks before senescence. The communities generally showed an early season LAI and TFN increase, owing to leaf development of deciduous shrubs, and limited variations later on, owing to concurrent leaf...

  3. Extreme dry spell detection and climatology over the Mediterranean Basin during the wet season

    Science.gov (United States)

    Raymond, Florian; Ullmann, Albin; Camberlin, Pierre; Drobinski, Philippe; Smith, Carmela Chateau

    2016-07-01

    The E-OBS precipitation gridded data set v.10.0 is used to detect very long dry spell (VLDS) events over the entire Mediterranean Basin for the 1957-2013 period, during the wet season (September to April). The main objective is to characterize these events as climatic objects, in terms of location, spatial extent, duration, and temporal variability. In this study, 76 VLDS events were detected in the Mediterranean Basin and grouped into four spatial patterns: scattered localized (with 25 events), northeast Mediterranean (11 events), West Mediterranean (15 events), and southeast Mediterranean (25 events). Each pattern shows seasonality in events. Most of the scattered localized, northeast, and southeast events begin in September, at the beginning of the wet season. In contrast, most of the West Mediterranean events begin in the middle of the wet season. Over time, there is a slight but not significant increase in the cumulative number of days per season affected by VLDS events.

  4. Vegetation response to rainfall seasonality and interannual variability in tropical dry forests

    Science.gov (United States)

    Feng, X.; Silva Souza, R. M.; Souza, E.; Antonino, A.; Montenegro, S.; Porporato, A. M.

    2015-12-01

    We analyzed the response of tropical dry forests to seasonal and interannual rainfall variability, focusing on the caatinga biome in semi-arid in Northeast Brazil. We selected four sites across a gradient of rainfall amount and seasonality and analyzed daily rainfall and biweekly Normalized Difference Vegetation Index (NDVI) in the period 2000-2014. The seasonal and interannual rainfall statistics were characterized using recently developed metrics describing duration, location, and intensity of wet season and compared them with those of NDVI time series and modelled soil moisture. A model of NDVI was also developed and forced by different rainfall scenarios (combination amount of rainfall and duration of wet season). The results show that the caatinga tends to have a more stable response characterized by longer and less variable growing seasons (of duration 3.1±0.1 months) compared to the rainfall wet seasons (2.0±0.5 months). Even for more extreme rainfall conditions, the ecosystem shows very little sensitivity to duration of wet season in relation to the amount of rainfall, however the duration of wet season is most evident for wetter sites. This ability of the ecosystem in buffering the interannual variability of rainfall is corroborated by the stability of the centroid location of the growing season compared to the wet season for all sites. The maximal biomass production was observed at intermediate levels of seasonality, suggesting a possible interesting trade-off in the effects of intensity (i.e., amount) and duration of the wet season on vegetation growth.

  5. Diet overlap of Propithecus verreauxi and Eulemur rufifrons during the late dry season in Kirindy Forest

    NARCIS (Netherlands)

    Winter, de I.I.; Gollner, A.; Akom, E.

    2013-01-01

    The aim of this short research project was to investigate whether two lemur species, Verreaux’s sifaka (Propithecus verreauxi) and the red-fronted brown lemur (Eulemur rufifrons), showed significant dietary overlap during the late dry season in Kirindy Forest in Madagascar. We hypothesised that the

  6. Seasonal variation in soil and plant water potentials in a Bolivian tropical moist and dry forest

    NARCIS (Netherlands)

    Markesteijn, L.; Iraipi, J.; Bongers, F.; Poorter, L.

    2010-01-01

    We determined seasonal variation in soil matric potentials (¿soil) along a topographical gradient and with soil depth in a Bolivian tropical dry (1160 mm y-1 rain) and moist forest (1580 mm y-1). In each forest we analysed the effect of drought on predawn leaf water potentials (¿pd) and drought resp

  7. Dry season mapping of savanna forage quality, using the hyperspectral Carnegie

    NARCIS (Netherlands)

    Knox, N.; Skidmore, A.K.; Prins, H.H.T.; Asner, P.; Werff, van der H.M.A.; Boer, de W.F.; Waal, van der C.; Knegt, de H.J.; Kohi, E.; Slotow, R.; Grant, R.C.

    2011-01-01

    Forage quality within an African savanna depends upon limiting nutrients (nitrogen and phosphorus) and nutrients that constrain the intake rates (non-digestible fibre) of herbivores. These forage quality nutrients are particularly crucial in the dry season when concentrations of limiting nutrients d

  8. Snow Cover and Precipitation Impacts on Dry Season Streamflow in the Lower Mekong Basin

    Science.gov (United States)

    Cook, Benjamin I.; Bell, A. R.; Anchukaitis, K. J.; Buckley, B. M.

    2012-01-01

    Climate change impacts on dry season streamflow in the Mekong River are relatively understudied, despite the fact that water availability during this time is critically important for agricultural and ecological systems. Analyses of two gauging stations (Vientiane and Kratie) in the Lower Mekong Basin (LMB) show significant positive correlations between dry season (March through May, MAM) discharge and upper basin snow cover and local precipitation. Using snow cover, precipitation, and upstream discharge as predictors, we develop skillful regression models for MAM streamflow at Vientiane and Kratie, and force these models with output from a suite of general circulation model (GCM) experiments for the twentieth and twenty-first centuries. The GCM simulations predict divergent trends in snow cover (decreasing) and precipitation (increasing) over the twenty-first century, driving overall negligible long-term trends in dry season streamflow. Our study demonstrates how future changes in dry season streamflow in the LMB will depend on changes in snow cover and precipitation, factors that will need to be considered when assessing the full basin response to other climatic and non-climatic drivers.

  9. Ecosystem Respiration Rates of Arctic Tundra Mesocosms in Response to Cold-Season Temperatures

    Science.gov (United States)

    Oberbauer, S. F.; Moser, J. G.; Olivas, P. C.; Starr, G.; Mortazavi, B.

    2013-12-01

    The cold season in the Arctic extends over 8 to 9 mo, during which air temperatures often reach as low as -40 °C. However, as a result of the insulating layer created by snow cover, temperatures seldom fall below -15 °C, and are likely warm enough to support some metabolism. Little research has been conducted on arctic plants and tundra during the cold season, despite its length and the fact that warming is predicted to be greatest during this period. The primary focus of cold-season research has been on rates of winter ecosystem respiration (ER) for estimates of annual carbon balance. The majority of these measurements during the winter or at winter temperatures indicate that some respiration is occurring. Although rates are low, they may contribute substantially to the annual carbon balance because of the length of the cold season. However, estimates of respiration at low temperatures differ substantially, have been taken at different temperatures using different methodologies, and importantly almost none provide quantitative relationships across a range of temperatures. We measured respiration rates of intact arctic tundra monoliths from 15 to -15 °C at 5 °C steps to facilitate improved model estimates of tundra respiration. Six tundra monoliths (~900 cm2) taken from Toolik Field Station, Alaska were conditioned for the cold season in growth chambers at shortened photoperiods and low, but above-freezing temperatures. Desired temperatures were obtained with a combination of growth chambers and a modified freezer. The average of five samplings of [CO2] at each temperature step was used to estimate the ER rates. Measurements were conducted with a closed system using incubation periods of 30 to 180 min, depending on the temperature. Carbon dioxide concentrations were measured by syringe samples injected into a N2 gas stream flowing through an infrared gas analyzer. Rates of ER calculated on an area basis were close to zero at -15 °C, but increased steadily with

  10. PONDERAL AND REPRODUCTIVE PERFORMANCE DURING RAIN SEASON OF NELLORE PRIMIPAROUS HEIFERS PREVIOUSLY SUPPLEMENTED WITH PROTEIN IN DRY SEASON

    Directory of Open Access Journals (Sweden)

    Ana Paula Carneiro Nogueira

    2015-07-01

    Full Text Available The objective of this study was to evaluate, in rainy season, the effect of protein complementation during dry season on Nellore primiparous heifers. We used 39 primiparous heifers, with an average age of 24-36 months, reared on Brachiaria decumbens and Brachiaria Brizantha pasture, for 205 days. The animals were weighed every 28 days, after fasting for 12 hours. The experimental design was a split plot, the two treatments were distributed in two installments, the six periods in subplots and the animals were the replications. The following variables were analyzed: weight, hip height, body condition score, average daily weight gain and average monthly growth, presenting the respective values of 318.5 kg, 142 cm, 3.24, 0.580 kg and 2.55 cm respectively for previously supplemented animals, and 309.6 kg, 141 cm, 3.23, 0.584 and 2.29 kg cm for non-supplemented animals. There were no significant differences between the two experimental groups. Pregnancy rate of supplemented animals was 57% and it did not differ from non-supplemented animals’ rate (45%. Calving rate was 100% for both groups. In the rainy season, after supplementation, heifers that did not receive supplementation during the dry period of the previous year had similar reproductive and weight performance as the supplemented ones.

  11. More stable productivity of semi natural grasslands than sown pastures in a seasonally dry climate.

    Directory of Open Access Journals (Sweden)

    Sonia Ospina

    Full Text Available In the Neotropics the predominant pathway to intensify productivity is generally thought to be to convert grasslands to sown pastures, mostly in monoculture. This article examines how above-ground net primary productivity (ANPP in semi-natural grasslands and sown pastures in Central America respond to rainfall by: (i assessing the relationships between ANPP and accumulated rainfall and indices of rainfall distribution, (ii evaluating the variability of ANPP between and within seasons, and (iii estimating the temporal stability of ANPP. We conducted sequential biomass harvests during 12 periods of 22 days and related those to rainfall. There were significant relationships between ANPP and cumulative rainfall in 22-day periods for both vegetation types and a model including a linear and quadratic term explained 74% of the variation in the data. There was also a significant correlation between ANPP and the number of rainfall events for both vegetation types. Sown pastures had higher ANPP increments per unit rainfall and higher ANPP at the peak of the rainy season than semi-natural grasslands. In contrast, semi-natural grasslands showed higher ANPP early in the dry season. The temporal stability of ANPP was higher in semi-natural grasslands than in the sown pastures in the dry season and over a whole annual cycle. Our results reveal that, contrary to conventional thinking amongst pasture scientists, there appears to be no increase in ANPP arising from replacing semi-natural grasslands with sown pastures under prevailing pasture management practices in seasonally dry climates, while the temporal distribution of ANPP is more even in semi-natural grasslands. Neither sown pastures nor semi-natural grasslands are productive towards the end of the dry season, indicating the potential importance of the widespread practice of retaining tree cover in pastures.

  12. More stable productivity of semi natural grasslands than sown pastures in a seasonally dry climate.

    Science.gov (United States)

    Ospina, Sonia; Rusch, Graciela M; Pezo, Danilo; Casanoves, Fernando; Sinclair, Fergus L

    2012-01-01

    In the Neotropics the predominant pathway to intensify productivity is generally thought to be to convert grasslands to sown pastures, mostly in monoculture. This article examines how above-ground net primary productivity (ANPP) in semi-natural grasslands and sown pastures in Central America respond to rainfall by: (i) assessing the relationships between ANPP and accumulated rainfall and indices of rainfall distribution, (ii) evaluating the variability of ANPP between and within seasons, and (iii) estimating the temporal stability of ANPP. We conducted sequential biomass harvests during 12 periods of 22 days and related those to rainfall. There were significant relationships between ANPP and cumulative rainfall in 22-day periods for both vegetation types and a model including a linear and quadratic term explained 74% of the variation in the data. There was also a significant correlation between ANPP and the number of rainfall events for both vegetation types. Sown pastures had higher ANPP increments per unit rainfall and higher ANPP at the peak of the rainy season than semi-natural grasslands. In contrast, semi-natural grasslands showed higher ANPP early in the dry season. The temporal stability of ANPP was higher in semi-natural grasslands than in the sown pastures in the dry season and over a whole annual cycle. Our results reveal that, contrary to conventional thinking amongst pasture scientists, there appears to be no increase in ANPP arising from replacing semi-natural grasslands with sown pastures under prevailing pasture management practices in seasonally dry climates, while the temporal distribution of ANPP is more even in semi-natural grasslands. Neither sown pastures nor semi-natural grasslands are productive towards the end of the dry season, indicating the potential importance of the widespread practice of retaining tree cover in pastures.

  13. Water discharge changes of the Changjiang River downstream Datong during dry season

    Institute of Scientific and Technical Information of China (English)

    CHENXiqing; WANGXiaoli; ZHANGErfeng

    2003-01-01

    Based on hydrometric data and extensive investigations on water-extracting projects, this paper presents a preliminary study on water discharge changes between Datong and Xuliujing during dry season. The natural hydrological processes and human factors that influence the water discharge are analyzed with the help of GIS method. The investigations indicate that the water-extracting projects downstream from Datong to Xuliujing had amounted to 64 in number by the end of 2000,with a water-extracting capacity up to 4,626 m3/s averaged in a tidal cycle. The water extraction from the Changjiang River has become the most important factor influencing the water discharge downstream Datong during dry season. The potential magnitude in water discharge changes are estimated based on historical records of water extraction and a water balance model. The computational results were calibrated with the actual data. The future trend in changes of water discharge into the sea during dry season was discussed by taking into consideration of newly built hydro-engineering projects. The water extraction downstream Datong in dry season before 2000 had a great influence on discharges into the sea in the extremely dry year like 1978-1979. It produced a net decrease of more than 490 m3/s in monthly mean discharges from the Changjiang into the sea. It is expected that the water extraction will continually increase in the coming decades, especially in dry years, when the net decrease in monthly mean water discharge will increase to more than 1000 m3/s and will give a far-reaching effect on the changes of water discharge from the Changjiang into the sea.

  14. Feeding Ecology of Taruca (Hippocamelus antisensis Populations during the Rainy and Dry Seasons in Central Peru

    Directory of Open Access Journals (Sweden)

    Carla Gazzolo

    2016-01-01

    Full Text Available Tarucas (Hippocamelus antisensis live in rocky areas in the Andes, from northern Peru to northern Argentina. Microhistological analyses on their feeding ecology during the rainy and dry seasons were done at a National Park and a Landscape Reserve. The diet was diverse and more than 50 species were identified from the feces. Grass species were most often detected as eaten by taruca during the rainy season comprising near 70% of the consumed fragments with 35 plant species identified as eaten then. In the dry season, around 50 species were identified as eaten by tarucas, mostly dicotyledonous. The main species consumed in both seasons were Werneria nubigena, Poa gymnantha, Senecio comosus, and Ephedra americana. The ecological density was an intermediate value compared to other observed values in Peru. This is the first study to find the importance of grasses for tarucas, selected when soft, during the rainy season. A possible overlap with domestic ungulates’ diets should be explored, helping the conservation of taruca and generating an adequate management of the species and the ecosystem. There is a change in the palatable offer of food items during the rainy season, when most of the Gramineae species are tender.

  15. Effects of drought stress on microbial dynamics in seasonally dry California ecosystems

    Science.gov (United States)

    Schaeffer, S. M.; Boot, C. M.; Doyle, A.; Clark, J.; Schimel, J. P.

    2008-12-01

    One of the key environmental factors controlling microbial activity is moisture. This water limitation is particularly strong in semi-arid and arid ecosystems such as those found along California's coast and interior range-lands. Cool, wet winters separated by long, dry summers present some the most challenging conditions for microbial survival and growth. Infrequent pulses of precipitation directly control microbial dynamics through soil wet-dry cycles, which in turn control the export of materials and nutrients into streams and groundwater. Recent research suggests that living microbial biomass can increase during the driest, hottest part of the year. We measured dissolved organic carbon and nitrogen (DOC, DON), microbial biomass carbon and nitrogen, inorganic nitrogen (NH4+, NO3-), and nitrification potential from July of 2007 to the present in California semi-arid grasslands. We also monitored inorganic nitrogen concentrations in soil pore water, shallow ground water, and stream water over the same period. Seasonal trends in DOC and DON show that they accumulate over the dry summer, and then decrease with the onset of the winter rains. Microbial biomass carbon showed a similar pattern, being higher in the summer and declining during winter (188.94±13.34 and 139.21±8.45 μg C g-1 dry soil respectively. However, biomass nitrogen remained unchanged over the same period (11.21±0.84 and 10.86±0.74 μg N g-1 dry soil respectively). Nitrification potentials were lowest during the winter wet season (5.26±0.40 μg N d-1 g-1 dry soil) and highest during the dry summer season (8.91±0.60 μg N d-1 g-1 dry soil). However, the seasonal patterns in NH4+ and NO3- availability suggest that net nitrification was not substantial until after the winter rains began. It is not currently known whether this increase in biomass represents actual growth of new organisms, or is a result of microbes accumulating internal solutes to avoid drying out. At the landscape-scale, these

  16. Analyzing the edge effects in a Brazilian seasonally dry tropical forest

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    D. M. Arruda

    Full Text Available Abstract Due to the deciduous nature of dry forests (widely known as seasonally dry tropical forests they are subject to microclimatic conditions not experienced in other forest formations. Close examinations of the theory of edge effects in dry forests are still rare and a number of questions arise in terms of this topic. In light of this situation we examined a fragment of the dry forest to respond to the following questions: (I Are there differences in canopy cover along the edge-interior gradient during the dry season? (II How does the microclimate (air temperature, soil temperature, and relative humidity vary along that gradient? (III How does the microclimate influence tree species richness, evenness and abundance along that gradient? (IV Are certain tree species more dominant closer to the forest edges? Regressions were performed to address these questions. Their coefficients did not significantly vary from zero. Apparently, the uniform openness of the forest canopy caused a homogeneous internal microclimate, without significant differentiation in habitats that would allow modifications in biotic variables tested. We conclude that the processes of edge effect commonly seen in humid forests, not was shared with the dry forest assessed.

  17. Control of dry season evapotranspiration over the Amazonian forest as inferred from observations at a southern Amazon forest site

    NARCIS (Netherlands)

    Negrón Juárez, R.I.; Hodnett, M.G.; Fu, R.; Goulden, M.L.; Randow, von C.

    2007-01-01

    The extent to which soil water storage can support an average dry season evapotranspiration (ET) is investigated using observations from the Rebio Jarú site for the period of 2000 to 2002. During the dry season, when total rainfall is less than 100 mm, the soil moisture storage available to root upt

  18. Dry season ecology of Anopheles gambiae complex mosquitoes in The Gambia

    Directory of Open Access Journals (Sweden)

    Bogh Claus

    2008-08-01

    Full Text Available Abstract Background Malaria in The Gambia is highly seasonal, with transmission occurring as Anopheles gambiae s.l. populations expand during and immediately after a single annual rainy season that lasts from June to October. There has been very limited investigation of the ecology of vectors during the dry season, when numbers are very limited and distributions may be restricted. Methods Weekly adult mosquito collections (pyrethrum spray, light trap, and search collections from rooms, as well as light trap collections from animal shelters, abandoned wells and grain stores, and artificial sentinel breeding site surveys were performed in four villages near the upper tidal and partially saline part of the Gambia River in the last four months of an annual dry season (March to June. Mosquito species were identified by morphological and DNA analysis, and ELISA assays were performed to test for Plasmodium falciparum sporozoites and human blood meal components. Results Adults of An. gambiae s.l. were collected throughout the period, numbers increasing towards the end of the dry season when humidity was increasing. Adult collections were dominated by An. melas (86%, with An. gambiae s.s. (10% and An. arabiensis (3% also present throughout. Most females collected in room search and spray collections contained blood meals, but most from light traps were unfed. None of the females tested (n = 1709 contained sporozoites. Larvae (mostly An. gambiae s.s. were recovered from artificial sentinel breeding sites in the two villages that had freshwater pools. These two villages had the highest proportions of An. gambiae s.s. adults, and experienced the most substantial increase in proportions of An. gambiae s.s. after the onset of rains. Conclusion During the dry season population minimum, An. melas was the predominant vector species, but differences among villages in availability of fresh-water breeding sites correlate with egg laying activity and relative

  19. Will seasonally dry tropical forests be sensitive or resistant to future changes in rainfall regimes?

    Science.gov (United States)

    Allen, Kara; Dupuy, Juan Manuel; Gei, Maria G.; Hulshof, Catherine; Medvigy, David; Pizano, Camila; Salgado-Negret, Beatriz; Smith, Christina M.; Trierweiler, Annette; Van Bloem, Skip J.; Waring, Bonnie G.; Xu, Xiangtao; Powers, Jennifer S.

    2017-02-01

    Seasonally dry tropical forests (SDTF) are located in regions with alternating wet and dry seasons, with dry seasons that last several months or more. By the end of the 21st century, climate models predict substantial changes in rainfall regimes across these regions, but little is known about how individuals, species, and communities in SDTF will cope with the hotter, drier conditions predicted by climate models. In this review, we explore different rainfall scenarios that may result in ecological drought in SDTF through the lens of two alternative hypotheses: 1) these forests will be sensitive to drought because they are already limited by water and close to climatic thresholds, or 2) they will be resistant/resilient to intra- and inter-annual changes in rainfall because they are adapted to predictable, seasonal drought. In our review of literature that spans microbial to ecosystem processes, a majority of the available studies suggests that increasing frequency and intensity of droughts in SDTF will likely alter species distributions and ecosystem processes. Though we conclude that SDTF will be sensitive to altered rainfall regimes, many gaps in the literature remain. Future research should focus on geographically comparative studies and well-replicated drought experiments that can provide empirical evidence to improve simulation models used to forecast SDTF responses to future climate change at coarser spatial and temporal scales.

  20. Diversity, structure and regeneration of the seasonally dry tropical forest of Yucatán Península, Mexico.

    OpenAIRE

    Hernández-Ramírez, Angélica María; García-Méndez, Socorro

    2015-01-01

    Seasonally dry tropical forests are considered as the most endangered ecosystem in lowland tropics. The aim of this study was to characterize the floristic composition, richness, diversity, structure and regeneration of a seasonally dry tropical forest landscape constituted by mature forest, secondary forest and seasonally inundated forest located in the Northeastern part of the Yucatán Península, Mexico. We used the Gentry’s standard inventory plot methodology (0.1 ha per forest type in 2007...

  1. Amazon Forests Maintain Consistent Canopy Structure and Greenness During the Dry Season

    Science.gov (United States)

    Morton, Douglas C.; Nagol, Jyoteshwar; Carabajal, Claudia C.; Rosette, Jacqueline; Palace, Michael; Cook, Bruce D.; Vermote, Eric F.; Harding, David J.; North, Peter R. J.

    2014-01-01

    The seasonality of sunlight and rainfall regulates net primary production in tropical forests. Previous studies have suggested that light is more limiting than water for tropical forest productivity, consistent with greening of Amazon forests during the dry season in satellite data.We evaluated four potential mechanisms for the seasonal green-up phenomenon, including increases in leaf area or leaf reflectance, using a sophisticated radiative transfer model and independent satellite observations from lidar and optical sensors. Here we show that the apparent green up of Amazon forests in optical remote sensing data resulted from seasonal changes in near-infrared reflectance, an artefact of variations in sun-sensor geometry. Correcting this bidirectional reflectance effect eliminated seasonal changes in surface reflectance, consistent with independent lidar observations and model simulations with unchanging canopy properties. The stability of Amazon forest structure and reflectance over seasonal timescales challenges the paradigm of light-limited net primary production in Amazon forests and enhanced forest growth during drought conditions. Correcting optical remote sensing data for artefacts of sun-sensor geometry is essential to isolate the response of global vegetation to seasonal and interannual climate variability.

  2. Biogenic cloud nuclei in the central Amazon during the transition from wet to dry season

    Science.gov (United States)

    Whitehead, James D.; Darbyshire, Eoghan; Brito, Joel; Barbosa, Henrique M. J.; Crawford, Ian; Stern, Rafael; Gallagher, Martin W.; Kaye, Paul H.; Allan, James D.; Coe, Hugh; Artaxo, Paulo; McFiggans, Gordon

    2016-08-01

    The Amazon basin is a vast continental area in which atmospheric composition is relatively unaffected by anthropogenic aerosol particles. Understanding the properties of the natural biogenic aerosol particles over the Amazon rainforest is key to understanding their influence on regional and global climate. While there have been a number of studies during the wet season, and of biomass burning particles in the dry season, there has been relatively little work on the transition period - the start of the dry season in the absence of biomass burning. As part of the Brazil-UK Network for Investigation of Amazonian Atmospheric Composition and Impacts on Climate (BUNIAACIC) project, aerosol measurements, focussing on unpolluted biogenic air masses, were conducted at a remote rainforest site in the central Amazon during the transition from wet to dry season in July 2013. This period marks the start of the dry season but before significant biomass burning occurs in the region. Median particle number concentrations were 266 cm-3, with size distributions dominated by an accumulation mode of 130-150 nm. During periods of low particle counts, a smaller Aitken mode could also be seen around 80 nm. While the concentrations were similar in magnitude to those seen during the wet season, the size distributions suggest an enhancement in the accumulation mode compared to the wet season, but not yet to the extent seen later in the dry season, when significant biomass burning takes place. Submicron nonrefractory aerosol composition, as measured by an aerosol chemical speciation monitor (ACSM), was dominated by organic material (around 81 %). Aerosol hygroscopicity was probed using measurements from a hygroscopicity tandem differential mobility analyser (HTDMA), and a quasi-monodisperse cloud condensation nuclei counter (CCNc). The hygroscopicity parameter, κ, was found to be low, ranging from 0.12 for Aitken-mode particles to 0.18 for accumulation-mode particles. This was consistent

  3. Spent nuclear fuel project cold vacuum drying facility safety equipment list

    Energy Technology Data Exchange (ETDEWEB)

    IRWIN, J.J.

    1999-02-24

    This document provides the safety equipment list (SEL) for the Cold Vacuum Drying Facility (CVDF). The SEL was prepared in accordance with the procedure for safety structures, systems, and components (SSCs) in HNF-PRO-516, ''Safety Structures, Systems, and Components,'' Revision 0 and HNF-PRO-097, Engineering Design and Evaluation, Revision 0. The SEL was developed in conjunction with HNF-SO-SNF-SAR-O02, Safety Analysis Report for the Cold Vacuum Drying Facility, Phase 2, Supporting Installation of Processing Systems (Garvin 1998). The SEL identifies the SSCs and their safety functions, the design basis accidents for which they are required to perform, the design criteria, codes and standards, and quality assurance requirements that are required for establishing the safety design basis of the SSCs. This SEL has been developed for the CVDF Phase 2 Safety Analysis Report (SAR) and shall be updated, expanded, and revised in accordance with future phases of the CVDF SAR until the CVDF final SAR is approved.

  4. Potential negative effects of groundwater dynamics on dry season convection in the Amazon River basin

    Science.gov (United States)

    Lin, Yen-Heng; Lo, Min-Hui; Chou, Chia

    2016-02-01

    Adding a groundwater component to land surface models affects modeled precipitation. The additional water supply from the subsurface contributes to increased water vapor in the atmosphere, resulting in modifications of atmospheric convection. This study focuses on how groundwater dynamics affect atmospheric convection in the Amazon River basin (ARB) during July, typically the driest month. Coupled groundwater-land-atmosphere model simulations show that groundwater storage increases evapotranspiration rates (latent heat fluxes) and lowers surface temperatures, which increases the surface pressure gradient and thus, anomalous surface divergence. Therefore, the convection over the Southern Hemispheric ARB during the dry season becomes weaker when groundwater dynamics are included in the model. Additionally, the changes in atmospheric vertical water vapor advection are associated with decreases in precipitation that results from downwelling transport anomalies. The results of this study highlight the importance of subsurface hydrological processes in the Amazon climate system, with implications for precipitation changes during the dry season, observed in most current climate models.

  5. Potential Negative Effects of Groundwater Dynamics on Dry Season Convection in the Amazon River Basin

    Science.gov (United States)

    Lin, Y. H.; Lo, M. H.; Chou, C.

    2014-12-01

    Adding a groundwater component to land surface models affects modeled precipitation because the additional water supply from the subsurface contributes to increased water vapor in the atmosphere, resulting in modifications of atmospheric convection. This study focused on how groundwater dynamics affect atmospheric convection in the Amazon River Basin (ARB) during July, typically the driest month. Coupled groundwater-land-atmosphere model simulations show that groundwater storage increases evapotranspiration rates (latent heat fluxes) and lowers surface temperatures, which increases the surface pressure gradient and thus, anomalous surface divergence. Therefore, the convection over the Southern Hemispheric ARB during the dry season becomes weaker when groundwater dynamics are included in the model. In addition, the changes in atmospheric vertical water vapor advection are associated with decreases in precipitation resulting from downward transport anomalies. The results of this study highlight the importance of subsurface hydrological processes in the Amazon climate system, which have implications for precipitation changes during the dry season observed in most current climate models.

  6. Coupled prediction of flood response and debris flow initiation during warm and cold season events in the Southern Appalachians, USA

    OpenAIRE

    Tao, J.; A. P. Barros

    2013-01-01

    Debris flows associated with rainstorms are a frequent and devastating hazard in the Southern Appalachians in the United States. Whereas warm season events are clearly associated with heavy rainfall intensity, the same cannot be said for the cold season events. Instead, there is a relationship between large (cumulative) rainfall events independently of season, and thus hydrometeorological regime, and debris flows. This suggests that the dynamics of subsurface hydrologic processes play an impo...

  7. Drying projection over western maritime continent during Southwest and Northeast monsoon seasons

    Science.gov (United States)

    Kartika Lestari, R.

    2017-04-01

    In the maritime continent, the precipitation variability is large and recently, this region experiences longer dry season and more number of severe drought events that are threatening the human life, such as, water supply for daily life and agriculture, and unhealthy air quality due to the increased number of wildfires. Global warming has been known to contribute to the rainfall anomalies around the world, and present study investigate the extent to which the drying conditions are going to be happened in 21st century over western part of the maritime continent (WMC), where the population is much larger than the eastern part, during both active Southwest (SW) and Northeast (NE) monsoon seasons. A future change in the precipitation over WMC is suggested from our analyses of the Coupled Model Intercomparison Project Phase 5 (CMIP5) models. In addition to CMIP5, we analyse the downscaled data of nine selected CMIP5 models to examine if there is modification in the drying projection when higher resolution data are used. While the north and south of equator show out of phase in the precipitation change, the region around equator shows decreased precipitation during both the SW monsoon in June-July-August-September (JJAS) and the peak of NE monsoon in February (FEB). The drying projection is robustly shown in FEB when Intertropical Convergence Zone (ITCZ) shift to the southern hemisphere, but the same robustness is not shown in JJAS when the monsoon over South China Sea is active. The detail results, including the mechanisms and the impacts of tropical climate features (such as, warming Pacific Ocean, monsoon, ITCZ) that drive the drying projection, and the possible reasons causing different degree in the robustness between two seasons, will be shown in the presentation.

  8. SPI drought class prediction using log-linear models applied to wet and dry seasons

    Science.gov (United States)

    Moreira, Elsa E.

    2016-08-01

    A log-linear modelling for 3-dimensional contingency tables was used with categorical time series of SPI drought class transitions for prediction of monthly drought severity. Standardized Precipitation Index (SPI) time series in 12- and 6-month time scales were computed for 10 precipitation time series relative to GPCC datasets with 2.5° spatial resolution located over Portugal and with 112 years length (1902-2014). The aim was modelling two-month step class transitions for the wet and dry seasons of the year and then obtain probability ratios - Odds - as well as their respective confidence intervals to estimate how probable a transition is compared to another. The prediction results produced by the modelling applied to wet and dry season separately, for the 6- and the 12-month SPI time scale, were compared with the results produced by the same modelling without the split, using skill scores computed for the entire time series length. Results point to good prediction performances ranging from 70 to 80% in the percentage of corrects (PC) and 50-70% in the Heidke skill score (HSS), with the highest scores obtained when the modelling is applied to the SPI12. The adding up of the wet and dry seasons introduced in the modelling brought improvements in the predictions, of about 0.9-4% in the PC and 1.3-6.8% in the HSS, being the highest improvements obtained in the SPI6 application.

  9. The length of the dry season may be associated with leaf scleromorphism in cerrado plants

    Directory of Open Access Journals (Sweden)

    MARCELO C. SOUZA

    2015-09-01

    Full Text Available Despite limitations of low fertility and high acidity of the soils, the cerrado flora is the richest amongst savannas. Many cerrado woody species show sclerophyllous leaves, which might be related to the availability of water and nutrients in the soil. To better understand the function and structure of cerrado vegetation within its own variations, we compared two cerrado communities: one in its core region in central Brazil (Brasília, DF and the other on its southern periphery (Itirapina, SP. We contrasted the length of the dry season, soil fertility rates, leaf concentrations of N, P, K, Ca and Mg and the specific leaf area (SLA between these communities. The dry season was shorter on the periphery, where the soil was more fertile although more acidic. Plants from the periphery showed higher SLA and higher leaf concentrations of N, P, Ca and Mg. We propose that the higher SLA of plants from the periphery is related to the shorter dry season, which allows better conditions for nutrient uptake.

  10. The length of the dry season may be associated with leaf scleromorphism in cerrado plants.

    Science.gov (United States)

    Souza, Marcelo C; Franco, Augusto C; Haridasan, Mundayatan; Rossatto, Davi R; de Araújo, Janaína F; Morellato, Leonor P C; Habermann, Gustavo

    2015-09-01

    Despite limitations of low fertility and high acidity of the soils, the cerrado flora is the richest amongst savannas. Many cerrado woody species show sclerophyllous leaves, which might be related to the availability of water and nutrients in the soil. To better understand the function and structure of cerrado vegetation within its own variations, we compared two cerrado communities: one in its core region in central Brazil (Brasília, DF) and the other on its southern periphery (Itirapina, SP). We contrasted the length of the dry season, soil fertility rates, leaf concentrations of N, P, K, Ca and Mg and the specific leaf area (SLA) between these communities. The dry season was shorter on the periphery, where the soil was more fertile although more acidic. Plants from the periphery showed higher SLA and higher leaf concentrations of N, P, Ca and Mg. We propose that the higher SLA of plants from the periphery is related to the shorter dry season, which allows better conditions for nutrient uptake.

  11. Penicillium salamii, a new species occurring during seasoning of dry-cured meat

    DEFF Research Database (Denmark)

    Perrone, Giancarlo; Samson, Robert A.; Frisvad, Jens Christian

    2015-01-01

    here as P. salamii. A literature search showed that this species occurs on (cured) meat products worldwide. In our study, P. salamii predominated the salami and capocollo surface in levels similar to the commonly known starter culture P. nalgiovense, irrespective of the room or age of seasoning......Fungi have an important role in the production of dry-cured meat products, especially during the seasoning period. In general, both industrially and handmade salami are quickly colonized by a composite mycobiota during seasoning, often with a strong predominance of Penicillium species...... "Penicillium milanense" isolated in Denmark and Slovenia on cured meats. The taxonomic position of these strains in Penicillium was investigated using calmodulin, β tubulin and ITS sequences, phenotypic characters and extrolite patterns, and resulted in the discovery of a new Penicillium species, described...

  12. Dry-season retreat and dietary shift of the dart-poison frog Dendrobates tinctorius (Anura: Dendrobatidae

    Directory of Open Access Journals (Sweden)

    Marga Born

    2010-07-01

    Full Text Available Seasonal rainfall affects tropical forest dynamics and behaviorof species that are part of these ecosystems. The positive correlation between amphibian activity patterns and rainfall has been demonstrated repeatedly. Members of Dendrobatidae, a clade of Neotropical dart-poison frogs, are well known for their habitat use and behavior during the rainy season, but their behavior during the dry season has received little attention. We studied habitat use and diet of the dendrobatid frog Dendrobates tinctorius in French Guiana during the rainy and dry seasons. Unlike many other dendrobatid frogs, D. tinctorius does not maintain territories for the entire rainy season. Both sexes colonize recently formed canopy-gaps and stay in these forest patches for only a few weeks. The frogs inthese patches consume a great diversity of prey, consisting of ants, beetles, wasps, insect larvae, and mites. During the dry season, frogs move to retreat sites in mature forest, such as palm bracts and tree holes. The frogs are less active and consume fewer prey items in the dry season, and they consume fewer wasps and insect larvae, but more termites. Ants are the most common prey items during both the wet and dry seasons. We discuss the effects of shifts in seasonal habitat use on the territorial behavior of dendrobatid frogs.

  13. Dry and wet rainy seasons in the Mantaro river basin (Central Peruvian Andes

    Directory of Open Access Journals (Sweden)

    Y. Silva

    2008-04-01

    Full Text Available Monthly precipitation data from the period of 1970 to 2004 from 38 meteorological stations in the Mantaro river basin were used to classify the rainy seasons (September–April of each year into anomalously dry or wet, and to determine the basin-wide extent of the anomalies based on the Standardized Precipitation Index (SPI. The wet periods mostly occurred in the early 1970's and during the first half of the 1980's, except for the event that occurred in the 1993/94 period which was the strongest and most generalized in the analyzed period. The dry periods occurred mostly during the second half of the 1980's and the 1990's. Consistent with this, a negative trend in precipitation of 2% per decade was found for the rainy season, due mainly to a stronger trend (−4%/decade during the peak phase (January–March.

    Despite previously reported significant negative correlations between El Niño-Southern Oscillation (ENSO and rainfall during the peak of the rainfall season, the similar amplitude variability of precipitation during the onset phase of the rainfall season (September–December, which is uncorrelated with ENSO, participate to the reduction of the absolute correlation for the full rainfall season. Correlations between rainfall in the Mantaro basin and sea surface temperature (SST in the tropical Atlantic are significant only near the end of the rainy season, with more rain associated with a weaker north-south difference in SST in the tropical Atlantic.

  14. Global Precipitation Measurement Cold Season Precipitation Experiment (GCPEx): For Measurement Sake Let it Snow

    Science.gov (United States)

    Skofronick-Jackson, Gail; Hudak, David; Petersen, Walter; Nesbitt, Stephen W.; Chandrasekar, V.; Durden, Stephen; Gleicher, Kirstin J.; Huang, Gwo-Jong; Joe, Paul; Kollias, Pavlos; Reed, Kimberly A.; Schwaller, Mathew R.; Stewart, Ronald; Tanelli, Simone; Tokay, Ali; Wang, James R.; Wolde, Mengistu

    2014-01-01

    As a component of the Earth's hydrologic cycle, and especially at higher latitudes,falling snow creates snow pack accumulation that in turn provides a large proportion of the fresh water resources required by many communities throughout the world. To assess the relationships between remotely sensed snow measurements with in situ measurements, a winter field project, termed the Global Precipitation Measurement (GPM) mission Cold Season Precipitation Experiment (GCPEx), was carried out in the winter of 2011-2012 in Ontario, Canada. Its goal was to provide information on the precipitation microphysics and processes associated with cold season precipitation to support GPM snowfall retrieval algorithms that make use of a dual-frequency precipitation radar and a passive microwave imager on board the GPM core satellite,and radiometers on constellation member satellites. Multi-parameter methods are required to be able to relate changes in the microphysical character of the snow to measureable parameters from which precipitation detection and estimation can be based. The data collection strategy was coordinated, stacked, high-altitude and in-situ cloud aircraft missions with three research aircraft sampling within a broader surface network of five ground sites taking in-situ and volumetric observations. During the field campaign 25 events were identified and classified according to their varied precipitation type, synoptic context, and precipitation amount. Herein, the GCPEx fieldcampaign is described and three illustrative cases detailed.

  15. Spent nuclear fuel project cold vacuum drying facility tempered water and tempered water cooling system design description

    Energy Technology Data Exchange (ETDEWEB)

    IRWIN, J.J.

    1998-11-30

    This document provides the System Design Description (SDD) for the Cold Vacuum Drying Facility (CVDF) Tempered Water (TW) and Tempered Water Cooling (TWC) System . The SDD was developed in conjunction with HNF-SD-SNF-SAR-002, Safety Analysis Report for the Cold Vacuum Drying Facility, Phase 2, Supporting Installation of Processing Systems (Garvin 1998), The HNF-SD-SNF-DRD-O02, 1998, Cold Vacuum Drying Facility Design Requirements, and the CVDF Design Summary Report. The SDD contains general descriptions of the TW and TWC equipment, the system functions, requirements and interfaces. The SDD provides references for design and fabrication details, operation sequences and maintenance. This SOD has been developed for the SNFP Operations Organization and shall be updated, expanded, and revised in accordance with future design, construction and startup phases of the CVDF until the CVDF final ORR is approved.

  16. A warm and wet Little Climatic Optimum and a cold and dry Little Ice Age in the southern Rocky Mountains, USA

    Energy Technology Data Exchange (ETDEWEB)

    Petersen, K.L.

    1992-05-01

    In the next century, increases in atmospheric trace gas concentration could warm the global average temperature beyond what it has ranged during the past century. Examination of larger-than-historic climatic changes that have occurred in the past in specific regions provides realistic context for evaluating such potential future changes. This paper has contrasted the climatic manifestation of the Little Climatic Optimum or Medieval Warm Period (AD 900--1300) with that of the Little Ice Age (AD 1300--1850) in the northern Colorado Plateau region of the southwestern USA. The zenith of the Anasazi occupation coincides with the former and their demise coincides with the latter, when conditions became too cold and especially dry (in the summer) to support upland dry farming. During the height of the Little Climatic Optimum the region was characterized by a relatively long growing season and greater winter and summer precipitation than that of today. This resulted in a relatively rapid development of a potential dry-farming belt that was twice as wide as the present and areas that cannot be dry farmed today were routinely farmed by the Anasazi. Such conditions would be beneficial to dry farmers in the Four Corners region if those conditions were repeated in the near future.

  17. The Formation of Charon's Red Poles from Seasonally Cold-Trapped Volatiles

    Science.gov (United States)

    Grundy, W. M.; Cruikshank, D. P.; Gladstone, D. R.; Howett, C. J. A.; Lauer, T. R.; Spencer, J. R.; Summers, M. E.; Buie, M. W.; Earle, A. M.; Ennico, K.; hide

    2016-01-01

    A unique feature of Plutos large satellite Charon is its dark red northern polar cap. Similar colours on Plutos surface have been attributed to tholin-like organic macromolecules produced by energetic radiation processing of hydrocarbons. The polar location on Charon implicates the temperature extremes that result from Charons high obliquity and long seasons in the production of this material. The escape of Pluto's atmosphere provides a potential feedstock for a complex chemistry. Gas from Pluto that is transiently cold-trapped and processed at Charon's winter pole was proposed as an explanation for the dark coloration on the basis of an image of Charon's northern hemisphere, but not modelled quantitatively. Here we report images of the southern hemisphere illuminated by Pluto-shine and also images taken during the approach phase that show the northern polar cap over a range of longitudes. We model the surface thermal environment on Charon and the supply and temporary cold-trapping of material escaping from Pluto, as well as the photolytic processing of this material into more complex and less volatile molecules while cold-trapped. The model results are consistent with the proposed mechanism for producing the observed colour pattern on Charon.

  18. SLUDGE TREATMENT PROJECT KOP DISPOSITION - THERMAL AND GAS ANALYSIS FOR THE COLD VACUUM DRYING FACILITY

    Energy Technology Data Exchange (ETDEWEB)

    SWENSON JA; CROWE RD; APTHORPE R; PLYS MG

    2010-03-09

    The purpose of this document is to present conceptual design phase thermal process calculations that support the process design and process safety basis for the cold vacuum drying of K Basin KOP material. This document is intended to demonstrate that the conceptual approach: (1) Represents a workable process design that is suitable for development in preliminary design; and (2) Will support formal safety documentation to be prepared during the definitive design phase to establish an acceptable safety basis. The Sludge Treatment Project (STP) is responsible for the disposition of Knock Out Pot (KOP) sludge within the 105-K West (KW) Basin. KOP sludge consists of size segregated material (primarily canister particulate) from the fuel and scrap cleaning process used in the Spent Nuclear Fuel process at K Basin. The KOP sludge will be pre-treated to remove fines and some of the constituents containing chemically bound water, after which it is referred to as KOP material. The KOP material will then be loaded into a Multi-Canister Overpack (MCO), dried at the Cold Vacuum Drying Facility (CVDF) and stored in the Canister Storage Building (CSB). This process is patterned after the successful drying of 2100 metric tons of spent fuel, and uses the same facilities and much of the same equipment that was used for drying fuel and scrap. Table ES-l present similarities and differences between KOP material and fuel and between MCOs loaded with these materials. The potential content of bound water bearing constituents limits the mass ofKOP material in an MCO load to a fraction of that in an MCO containing fuel and scrap; however, the small particle size of the KOP material causes the surface area to be significantly higher. This relatively large reactive surface area represents an input to the KOP thermal calculations that is significantly different from the calculations for fuel MCOs. The conceptual design provides for a copper insert block that limits the volume available to

  19. Elevated Temperature and CO2 Stimulate Late-Season Photosynthesis But Impair Cold Hardening in Pine.

    Science.gov (United States)

    Chang, Christine Y; Fréchette, Emmanuelle; Unda, Faride; Mansfield, Shawn D; Ensminger, Ingo

    2016-10-01

    Rising global temperature and CO2 levels may sustain late-season net photosynthesis of evergreen conifers but could also impair the development of cold hardiness. Our study investigated how elevated temperature, and the combination of elevated temperature with elevated CO2, affected photosynthetic rates, leaf carbohydrates, freezing tolerance, and proteins involved in photosynthesis and cold hardening in Eastern white pine (Pinus strobus). We designed an experiment where control seedlings were acclimated to long photoperiod (day/night 14/10 h), warm temperature (22°C/15°C), and either ambient (400 μL L(-1)) or elevated (800 μmol mol(-1)) CO2, and then shifted seedlings to growth conditions with short photoperiod (8/16 h) and low temperature/ambient CO2 (LTAC), elevated temperature/ambient CO2 (ETAC), or elevated temperature/elevated CO2 (ETEC). Exposure to LTAC induced down-regulation of photosynthesis, development of sustained nonphotochemical quenching, accumulation of soluble carbohydrates, expression of a 16-kD dehydrin absent under long photoperiod, and increased freezing tolerance. In ETAC seedlings, photosynthesis was not down-regulated, while accumulation of soluble carbohydrates, dehydrin expression, and freezing tolerance were impaired. ETEC seedlings revealed increased photosynthesis and improved water use efficiency but impaired dehydrin expression and freezing tolerance similar to ETAC seedlings. Sixteen-kilodalton dehydrin expression strongly correlated with increases in freezing tolerance, suggesting its involvement in the development of cold hardiness in P. strobus Our findings suggest that exposure to elevated temperature and CO2 during autumn can delay down-regulation of photosynthesis and stimulate late-season net photosynthesis in P. strobus seedlings. However, this comes at the cost of impaired freezing tolerance. Elevated temperature and CO2 also impaired freezing tolerance. However, unless the frequency and timing of extreme low

  20. The effect of drying and urea treatment on nutritional and anti-nutritional components of browses collected during wet and dry seasons

    Energy Technology Data Exchange (ETDEWEB)

    Vitti, D.M.S.S. [Centre for Nuclear Energy in Agriculture, University of Sao Paulo, Piracicaba, SP (Brazil)]. E-mail: dovitti@cena.usp.br; Nozella, E.F.; Abdalla, A.L.; Bueno, I.C.S.; Longo, C.; Cabral Filho, S.L.S.; Godoy, P.B. [Centre for Nuclear Energy in Agriculture, University of Sao Paulo, Piracicaba, SP (Brazil); Silva Filho, J.C. [Universidade Federal de Lavras, Lavras, MG (Brazil); Costa, C. [Faculdade de Medicina Veterinaria e Zootecnia, UNESP, Botucatu, SP (Brazil); Bueno, M.S. [Instituto de Zootecnia, Nova Odessa, SP (Brazil); Vieira, M.E.Q. [Universidade Federal Rural de Pernambuco, Recife, PE (Brazil); Mueller-Harvey, I. [Agriculture Department, University of Reading, Reading (United Kingdom)

    2005-08-19

    Fibre, crude protein and tannin concentrations were measured in browse species from the semi-arid region of Northeast Brazil during the dry and wet seasons. The effects of oven-, sun- and shade-drying and of urea treatment were also determined. Crude protein (CP) content varied from 103 to 161 g/kg dry matter (DM) and the browses had similar CP content in the two seasons (during 2002) (102-161 and 107-153 g/kg DM in the wet and dry seasons, respectively). Total tannin concentrations ranged from 13 to 201 g/kg DM amongst the browses and were higher in the dry season. A 30-d treatment with urea reduced extractable tannins significantly (P < 0.05). The urea treatment was also most effective at reducing the in vitro effects of tannins compared to the other drying treatments. This was demonstrated by measuring the effect of polyethylene glycol (PEG) on gas production. Addition of PEG increased gas production of oven- (81.4%), sun- (78.5%) and shade-dried (76.7%) samples much more compared to urea treated samples (10.9%). (author)

  1. High but not dry: diverse epiphytic bromeliad adaptations to exposure within a seasonally dry tropical forest community.

    Science.gov (United States)

    Reyes-García, C; Mejia-Chang, M; Griffiths, H

    2012-02-01

    • Vascular epiphytes have developed distinct lifeforms to maximize water uptake and storage, particularly when delivered as pulses of precipitation, dewfall or fog. The seasonally dry forest of Chamela, Mexico, has a community of epiphytic bromeliads with Crassulacean acid metabolism showing diverse morphologies and stratification within the canopy. We hypothesize that niche differentiation may be related to the capacity to use fog and dew effectively to perform photosynthesis and to maintain water status. • Four Tillandsia species with either 'tank' or 'atmospheric' lifeforms were studied using seasonal field data and glasshouse experimentation, and compared on the basis of water use, leaf water δ(18) O, photosynthetic and morphological traits. • The atmospheric species, Tillandsia eistetteri, with narrow leaves and the lowest succulence, was restricted to the upper canopy, but displayed the widest range of physiological responses to pulses of precipitation and fog, and was a fog-catching 'nebulophyte'. The other atmospheric species, Tillandsia intermedia, was highly succulent, restricted to the lower canopy and with a narrower range of physiological responses. Both upper canopy tank species relied on tank water and stomatal closure to avoid desiccation. • Niche differentiation was related to capacity for water storage, dependence on fog or dewfall and physiological plasticity. © 2011 The Authors. New Phytologist © 2011 New Phytologist Trust.

  2. Germination season and watering regime, but not seed morph, affect life history traits in a cold desert diaspore-heteromorphic annual.

    Directory of Open Access Journals (Sweden)

    Juan J Lu

    Full Text Available Seed morph, abiotic conditions and time of germination can affect plant fitness, but few studies have tested their combined effects on plasticity of plant life history traits. Thus, we tested the hypothesis that seed morph, germination season and watering regime influence phenotypic expression of post-germination life history traits in the diaspore-heteromorphic cold desert winter annual/spring ephemeral Diptychocarpus strictus. The two seed morphs were sown in watered and non-watered plots in late summer, and plants derived from them were watered or not-watered throughout the study. Seed morph did not affect phenology, growth and morphology, survival, dry mass accumulation and allocation or silique and seed production. Seeds in watered plots germinated in autumn (AW and spring (SW but only in spring for non-watered plots (SNW. A high percentage of AW, SW and SNW plants survived and reproduced, but flowering date and flowering period of autumn- vs. spring-germinated plants differed. Dry mass also differed with germination season/watering regime (AW > SW > SNW. Number of siliques and seeds increased with plant size (AW > SW > SNW, whereas percent dry mass allocated to reproduction was higher in small plants: SNW > SW > AW. Thus, although seed morph did not affect the expression of life history traits, germination season and watering regime significantly affected phenology, plant size and accumulation and allocation of biomass to reproduction. Flexibility throughout the life cycle of D. strictus is an adaptation to the variation in timing and amount of rainfall in its cold desert habitat.

  3. Projected changes of rainfall seasonality and dry spells in a high greenhouse gas emissions scenario

    Science.gov (United States)

    Pascale, Salvatore; Lucarini, Valerio; Feng, Xue; Porporato, Amilcare; ul Hasson, Shabeh

    2016-02-01

    In this diagnostic study we analyze changes of rainfall seasonality and dry spells by the end of the twenty-first century under the most extreme IPCC5 emission scenario (RCP8.5) as projected by twenty-four coupled climate models contributing to Coupled Model Intercomparison Project 5 (CMIP5). We use estimates of the centroid of the monthly rainfall distribution as an index of the rainfall timing and a threshold-independent, information theory-based quantity such as relative entropy (RE) to quantify the concentration of annual rainfall and the number of dry months and to build a monsoon dimensionless seasonality index (DSI). The RE is projected to increase, with high inter-model agreement over Mediterranean-type regions—southern Europe, northern Africa and southern Australia—and areas of South and Central America, implying an increase in the number of dry days up to 1 month by the end of the twenty-first century. Positive RE changes are also projected over the monsoon regions of southern Africa and North America, South America. These trends are consistent with a shortening of the wet season associated with a more prolonged pre-monsoonal dry period. The extent of the global monsoon region, characterized by large DSI, is projected to remain substantially unaltered. Centroid analysis shows that most of CMIP5 projections suggest that the monsoonal annual rainfall distribution is expected to change from early to late in the course of the hydrological year by the end of the twenty-first century and particularly after year 2050. This trend is particularly evident over northern Africa, southern Africa and western Mexico, where more than 90 % of the models project a delay of the rainfall centroid from a few days up to 2 weeks. Over the remaining monsoonal regions, there is little inter-model agreement in terms of centroid changes.

  4. Seasonality in the Dung Beetle Community in a Brazilian Tropical Dry Forest: Do Small Changes Make a Difference?

    Science.gov (United States)

    Medina, Anderson Matos; Lopes, Priscila Paixão

    2014-01-01

    Dung beetle (Coleoptera: Scarabaeoidea: Scarabaeinae) activity is influenced by rainfall seasonality. We hypothesized that rainfall might also play a major role in regulating the community structure of this group. In this study, we describe seasonal changes in the richness, composition, and structure of the Scarabaeinae community in a Brazilian tropical dry forest. A fragment of arboreal Caatinga was sampled using baited pitfall traps during the early dry season (EDS), late dry season (LDS), early wet season (EWS), and middle wet season (MWS). We compared the dung beetle community in each season in relationship to species richness, rank-dominance, curves, and composition. We collected 1352 Scarabaeinae individuals , belonging to 15 species. Dichotomius aff. laevicollis Felsche (Coleoptera: Scarabaeidae) was the dominant species, representing 73.89% of the individuals. There were no seasonal changes in the rank dominance curves; all had a single dominant species and a few species with low abundance, typical for arid areas. Estimated richness was highest in MWS, followed by EWS. Dry-season samples (EDS and LDS) had lower richness, with no significant difference between the dry seasons. Although species richness increased as the habitat became wetter, the difference between the wet and dry seasons was small, which differs completely from the findings of other studies in Neotropical dry forests, where almost all species cease activities in the dry season. Species composition changes were found in non-metric multidimensional scaling and sustained by analysis of similarity. All the seasons had pairwise differences in composition, with the exception of EDS and MWS, which indicates that the dung beetle community in this fragment requires more than three months of drought to trigger changes in species composition; this is probably due to small changes in the forest canopy. There was no difference in composition between EDS and MWS. As in other tropical dry forests, although

  5. Criticality safety evaluation report for the Cold Vacuum Drying Facility`s process water handling system

    Energy Technology Data Exchange (ETDEWEB)

    Roblyer, S.D.

    1998-02-12

    This report addresses the criticality concerns associated with process water handling in the Cold Vacuum Drying Facility (CVDF). The controls and limitations on equipment design and operations to control potential criticality occurrences are identified. The effectiveness of equipment design and operation controls in preventing criticality occurrences during normal and abnormal conditions is evaluated and documented in this report. Spent nuclear fuel (SNF) is removed from existing canisters in both the K East and K West Basins and loaded into a multicanister overpack (MCO) in the K Basin pool. The MCO is housed in a shipping cask surrounded by clean water in the annulus between the exterior of the MCO and the interior of the shipping cask. The fuel consists of spent N Reactor and some single pass reactor fuel. The MCO is transported to the CVDF near the K Basins to remove process water from the MCO interior and from the shipping cask annulus. After the bulk water is removed from the MCO, any remaining free liquid is removed by drawing a vacuum on the MCO`s interior. After cold vacuum drying is completed, the MCO is filled with an inert cover gas, the lid is replaced on the shipping cask, and the MCO is transported to the Canister Storage Building. The process water removed from the MCO contains fissionable materials from metallic uranium corrosion. The process water from the MCO is first collected in a geometrically safe process water conditioning receiver tank. The process water in the process water conditioning receiver tank is tested, then filtered, demineralized, and collected in the storage tank. The process water is finally removed from the storage tank and transported from the CVDF by truck.

  6. Flux frequency analysis of seasonally dry ecosystem fluxes in two unique biomes of Sonora Mexico

    Science.gov (United States)

    Verduzco, V. S.; Yepez, E. A.; Robles-Morua, A.; Garatuza, J.; Rodriguez, J. C.; Watts, C.

    2013-05-01

    Complex dynamics from the interactions of ecosystems processes makes difficult to model the behavior of ecosystems fluxes of carbon and water in response to the variation of environmental and biological drivers. Although process oriented ecosystem models are critical tools for studying land-atmosphere fluxes, its validity depends on the appropriate parameterization of equations describing temporal and spatial changes of model state variables and their interactions. This constraint often leads to discrepancies between model simulations and observed data that reduce models reliability especially in arid and semiarid ecosystems. In the semiarid north western Mexico, ecosystem processes are fundamentally controlled by the seasonality of water and the intermittence of rain pulses which are conditions that require calibration of specific fitting functions to describe the response of ecosystem variables (i.e. NEE, GPP, ET, respiration) to these wetting and drying periods. The goal is to find functions that describe the magnitude of ecosystem fluxes during individual rain pulses and the seasonality of the ecosystem. Relaying on five years of eddy covariance flux data of a tropical dry forest and a subtropical shrubland we present a flux frequency analysis that describe the variation of net ecosystem exchange (NEE) of CO2 to highlight the relevance of pulse driven dynamics controlling this flux. Preliminary results of flux frequency analysis of NEE indicate that these ecosystems are strongly controlled by the frequency distribution of rain. Also, the output of fitting functions for NEE, GPP, ET and respiration using semi-empirical functions applied at specific rain pulses compared with season-long statistically generated simulations do not agree. Seasonality and the intrinsic nature of individual pulses have different effects on ecosystem flux responses. This suggests that relationships between the nature of seasonality and individual pulses can help improve the

  7. Penicillium salamii, a new species occurring during seasoning of dry-cured meat.

    Science.gov (United States)

    Perrone, Giancarlo; Samson, Robert A; Frisvad, Jens C; Susca, Antonia; Gunde-Cimerman, Nina; Epifani, Filomena; Houbraken, Jos

    2015-01-16

    Fungi have an important role in the production of dry-cured meat products, especially during the seasoning period. In general, both industrially and handmade salami are quickly colonized by a composite mycobiota during seasoning, often with a strong predominance of Penicillium species. These species are involved in the improvement of the characteristics and taste, and in the prevention of the growth of pathogenic, toxigenic or spoilage fungi. During the survey of fungal species occurring on the salami surface and in the air of the seasoning and storage areas of a salami plant (Calabria, Italy), two Penicillium species were predominantly present. One species was identified as Penicillium nalgiovense, and the other was related to, but distinct from, Penicillium olsonii. Further molecular and biochemical analyses showed that this strain has high homology with the not yet described species named "Penicillium milanense" isolated in Denmark and Slovenia on cured meats. The taxonomic position of these strains in Penicillium was investigated using calmodulin, β tubulin and ITS sequences, phenotypic characters and extrolite patterns, and resulted in the discovery of a new Penicillium species, described here as P. salamii. A literature search showed that this species occurs on (cured) meat products worldwide. In our study, P. salamii predominated the salami and capocollo surface in levels similar to the commonly known starter culture P. nalgiovense, irrespective of the room or age of seasoning. Preliminary inoculation trials with P. salamii showed that it was able to colonize salami during seasoning, indicating that this species could be used as a fungal starter for dry-cured meat. Copyright © 2014. Published by Elsevier B.V.

  8. Effect of Dietary Types on Feed Intakes, Growth Performance and Economic Benefit in Tibetan sheep and Yaks on the Qinghai-Tibet Plateau during Cold Season.

    Science.gov (United States)

    Xu, Tianwei; Xu, Shixiao; Hu, Linyong; Zhao, Na; Liu, Zhe; Ma, Li; Liu, Hongjin; Zhao, Xinquan

    2017-01-01

    Pastoralists on the Tibetan alpine rangeland suffered great economic loss in cold season, due to serious live-weight loss of domestic livestock under traditional grazing management. This study aimed to evaluate the effect of dietary types (crude protein levels) on feed intakes, growth performance and economic returns of local Tibetan sheep and yaks during cold season. Twenty-four yearling Tibetan sheep (25.29±3.95 kg LW) and twenty two-year-old yaks (100.62±4.55 kg LW) with familiar body conditions were randomly assigned to four groups, fed oats hay (OH), oats silage (OS), total mixed ration (TMR) and traditionally grazed on the local cool-season pasture (TG), respectively, over a 135-day experiment. Daily dry matter intake was determined; all animals were weighed at the beginning and every 15 days of the 135-day experiment. Then, the total live-weight gain, average daily live-weight gain, gain rate, feed efficiency and net economic benefit were calculated. Results indicated that feed and nutrient intakes (DMI, DMI/kg LW, DMI/kg LW0.75 and CPI) of TMR, OH and OS were higher than TG (P performance and feed efficiency, obtained the highest breeding profit in both Tibetan sheep and yaks among four treatments (P economic benefit, TMR shared the highest net economic benefit in Tibetan sheep, OH shared the highest net economic benefit in yaks, but, no significant difference of net economic benefit in yaks fed TMR and OH diets was determined (P > 0.05). Results indicated that TMR was a reasonable diet in promoting feed intakes, animal performance, feed efficiency and economic returns in domestic livestock, which should be considered by local herdsmen to increase their breeding profit during cold season.

  9. Seasonal variations of phytoplankton phosphorus stress in the Yellow Sea Cold Water Mass

    Institute of Scientific and Technical Information of China (English)

    WANG Dan; HUANG Bangqin; LIU Xin; LIU Guimei; WANG Hui

    2014-01-01

    The Yellow Sea is located between the China Mainland and the Korean Peninsula, representing a typical shallow epicontinental sea. The Yellow Sea Cold Water Mass (YSCWM) is one of the most important physical features in the Yellow Sea. The characteristics of vertical profiles and seasonal variations of biogenic ele-ments in the YSCWM may lead the variations of nutrient availability (e.g., phosphorus) and phosphorus stress of phytoplankton. In this study, the authors surveyed the seasonal variations of phytoplankton phos-phorus stress with emphasis on the effect of the YSCWM during the four cruises in April and October 2006, March and August 2007. Using both bulk and single-cell alkaline phosphatase activity (APA) assays, this study evaluated phosphorus status of phytoplankton community, succession of phytoplankton community and ecophysiological responses of phytoplankton to phosphorus in the typical region of the YSCWM. With the occurrence of the YSCWM, especially the variations of concentration of dissolved inorganic phospho-rus (DIP), the results of bulk APA appeared corresponding seasonal variations. Along Transects A and B, the mean APA in August was the highest, and that in March was the lowest. According to the ELF-labeled assay’s results, seasonal variations of the ELF-labeled percentages within dominant species indicated that diatoms were dominant in March, April and October, while dinoflagellates were dominant in August. During the four cruises, the ELF-labeled percentages of diatoms except Paralia sulcata showed that diatoms were not phosphorus deficient in April 2006 at all, but suffered from severe phosphorus stress in August 2007. In comparison, the ELF-labeled percentages of dinoflagellates were all above 50%during the four time series, which meant dinoflagellates such as Alexandrium and Scrippsiella, sustained perennial phosphorus stress.

  10. Biophysical characteristics of a morphologically-complex macrotidal tropical coastal system during a dry season

    Science.gov (United States)

    Jones, N. L.; Patten, N. L.; Krikke, D. L.; Lowe, R. J.; Waite, A. M.; Ivey, G. N.

    2014-08-01

    Four boat-based surveys and several moored measurements were conducted over the dry season in June, July, August and September 2008 in the central Kimberley region of northwestern Australia; a macrotidal tropical coastal region, characterised by numerous island archipelagos and shallow reefs. The objective was to determine the influence of this complex morphology on the biophysical properties of the local coastal water masses and the resultant impact on phytoplankton biomass. Despite negligible rainfall during the dry-season, decreased salinity towards the coast suggested a persistent fresh water source. The water column was weakly vertically-stratified throughout much of the study region, only becoming well-mixed in topographically constricted regions. The vertical stratification resulted in a cross-shore subsurface in situ chl-a fluorescence maxima (at ˜30 m depth) in June, July and August. The presence of a chain of islands and shallow reefs led to the partial isolation of the semi-enclosed embayment, Collier Bay, creating distinct water masses across this relatively small area. The confluence of the two most distinct water masses formed a front at latitude ˜15.65-15.7 °S, in both June and August, indicating it was a persistent feature during the dry season. In situ chl-a fluorescence was highest at the front location. In Collier Bay, NOx concentrations were up to five times higher, with a 20% higher proportion of larger extracted chl-a biomass (cells > 5 μm), a proxy for phytoplankton. In the more open waters of Camden Sound, relatively high concentrations of picophytoplankton, bacteria and viruses were observed. Such spatial shifts in nutrient concentrations, phytoplankton biomass and phytoplankton and microbial community composition across the persistent density front are likely to have important consequences on the region's planktonic food web function.

  11. Estimating Evapotranspiration Demands of Different Land Cover Using Diurnal Signals in Dry Season Stream Discharge

    Science.gov (United States)

    Bhalla, R. S.; K, K.; Srinivas, V.; Krishnaswamy, J.; Chappell, N. A.; Jones, T.

    2015-12-01

    We use a paired catchment approach to compare the dry season flows between natural grasslands and introduced plantations of black wattle (Acacia mearnsii) in the Nilgiri South range forest which lies in the southern parts of the Western Ghat mountain range in Sothern India, a global biodiversity hot-spot. Discharges were measured using a portable flume and a weir fitted with capacitance probes logging water levels every five minutes in two adjacent catchments. Sensor artefacts in the data were filtered out before analysis. Diurnal variations in dry season flows from March 1st to April 15th, 2014 were used to estimate the daily ET based on Boronina et al. 2005 (Hyd. Proc. 19, 20, pp. 4055-4068.) using the equation 1. : E T daily = ∑ i=1 24 ( Q max - Q i ) Δ t , where E T daily is the daily loss of water from the catchment through ET, Q max is the daily maximum flow rate in the river, Q i is the average flow rate for every hour of the day and Δ t is one hour. Our results show that land use conversion from grasslands to wattle has increased ET by 40.97mm which is to the order of 60% during the period of the study (table 1). This has immediate relevance for dry season flows in the region. Nilgiris provide 40% of the total hydro-power generation for the state of Tamil Nadu and these streams sustain biodiversity and are tributaries of the Cauvery river, the largest the state. They also highlight the potential consequences of programmes such as the National Mission for Greening India which explicitly targets conversions of 10m ha of degraded forests, scrub and grasslands to tree cover and forest. Grassland Wattle Difference 1st Qu. 1.14 1.36 -1.33 Median 1.94 2.04 0.28 Mean 2.06 2.97 0.91 3rd Qu. 2.66 3.51 2.43 Sum 92.63 133.60 40.97 Table 1: Summary statistics for daily dry season ET for catchment under grassland, wattle and the daily differences between the two in mm per day.

  12. Water source partitioning among trees growing on shallow karst soils in a seasonally dry tropical climate.

    Science.gov (United States)

    Querejeta, José Ignacio; Estrada-Medina, Héctor; Allen, Michael F; Jiménez-Osornio, Juan José

    2007-05-01

    The sources of water used by woody vegetation growing on karst soils in seasonally dry tropical regions are little known. In northern Yucatan (Mexico), trees withstand 4-6 months of annual drought in spite of the small water storage capacity of the shallow karst soil. We hypothesized that adult evergreen trees in Yucatan tap the aquifer for a reliable supply of water during the prolonged dry season. The naturally occurring concentration gradients in oxygen and hydrogen stable isotopes in soil, bedrock, groundwater and plant stem water were used to determine the sources of water used by native evergreen and drought-deciduous tree species. While the trees studied grew over a permanent water table (9-20 m depth), pit excavation showed that roots were largely restricted to the upper 2 m of the soil/bedrock profile. At the peak of the dry season, the delta(18)O signatures of potential water sources for the vegetation ranged from 4.1 +/- 1.1 per thousand in topsoil to -4.3 +/- 0.1 per thousand in groundwater. The delta(18)O values of tree stem water ranged from -2.8 +/- 0.3 per thousand in Talisia olivaeformis to 0.8 +/- 1 per thousand in Ficus cotinifolia, demonstrating vertical partitioning of soil/bedrock water among tree species. Stem water delta(18)O values were significantly different from that of groundwater for all the tree species investigated. Stem water samples plotted to the right of the meteoric water line, indicating utilization of water sources subject to evaporative isotopic enrichment. Foliar delta(13)C in adult trees varied widely among species, ranging from -25.3 +/- 0.3 per thousand in Enterolobium cyclocarpum to -28.7 +/- 0.4 per thousand in T. olivaeformis. Contrary to initial expectations, data indicate that native trees growing on shallow karst soils in northern Yucatan use little or no groundwater and depend mostly on water stored within the upper 2-3 m of the soil/bedrock profile. Water storage in subsurface soil-filled cavities and in the

  13. Documentary realism and film pleasure: Two moments from Euzhan Palcy’s A Dry White Season

    Directory of Open Access Journals (Sweden)

    J. Higgins

    1992-05-01

    Full Text Available This essay examines some of the strains and tensions around the notions of film pleasure and documentary realism in the film A Dry White Season. It offers a schematic analysis of the history of the idea of a politics of film pleasure in the early work on mass culture of the Frankfurt School and F.R. Leavis, and more recent debates in feminism. This general account then provides the context for the examination of some of the problems in Palcy's film, focusing particularly on the question of Palcy's claims for a documentary realism, and two particular moments in the film itself.

  14. Plant water resource partitioning and isotopic fractionation during transpiration in a seasonally dry tropical climate

    Science.gov (United States)

    De Wispelaere, Lien; Bodé, Samuel; Hervé-Fernández, Pedro; Hemp, Andreas; Verschuren, Dirk; Boeckx, Pascal

    2017-01-01

    Lake Chala (3°19' S, 37°42' E) is a steep-sided crater lake situated in equatorial East Africa, a tropical semiarid area with a bimodal rainfall pattern. Plants in this region are exposed to a prolonged dry season, and we investigated if (1) these plants show spatial variability and temporal shifts in their water source use; (2) seasonal differences in the isotopic composition of precipitation are reflected in xylem water; and (3) plant family, growth form, leaf phenology, habitat and season influence the xylem-to-leaf water deuterium enrichment. In this study, the δ2H and δ18O of precipitation, lake water, groundwater, plant xylem water and plant leaf water were measured across different plant species, seasons and plant habitats in the vicinity of Lake Chala. We found that plants rely mostly on water from the short rains falling from October to December (northeastern monsoon), as these recharge the soil after the long dry season. This plant-available, static water pool is only slightly replenished by the long rains falling from February to May (southeastern monsoon), in agreement with the two water worlds hypothesis, according to which plants rely on a static water pool while a mobile water pool recharges the groundwater. Spatial variability in water resource use exists in the study region, with plants at the lakeshore relying on a water source admixed with lake water. Leaf phenology does not affect water resource use. According to our results, plant species and their associated leaf phenology are the primary factors influencing the enrichment in deuterium from xylem water to leaf water (ɛl/x), with deciduous species giving the highest enrichment, while growth form and season have negligible effects. Our observations have important implications for the interpretation of δ2H of plant leaf wax n-alkanes (δ2Hwax) from paleohydrological records in tropical East Africa, given that the temporal variability in the isotopic composition of precipitation is not

  15. Formation of Authigenic Sulfates in Cold Dry Glaciers: Terrestrial and Planetary Implications of Sublimites

    Science.gov (United States)

    Massé, M.; Rondeau, B.; Ginot, P.; Schmitt, B.; Bourgeois, O.; Mitri, G.

    2015-12-01

    Salts are common on planetary surfaces, and sulfates have been widely observed on Earth, Mars (Gendrin et al., 2005) and on some of Jupiter's and Saturn's icy moons like Europa (Dalton et al., 2007). These minerals can form under a wide range of conditions, and the determination of sulfate formation processes can provide key elements for deciphering past planetary surface conditions. Most terrestrial sulfates form as evaporites in warm environments with high water/rock ratios, but these conditions are rarely encountered on other planets. Here we describe the formation of cryogenic sulfates in an extreme cold and dry environment: the Guanaco glacier located in the Chilean Andes (Fig.1a, Rabatel et al., 2011). Field analyses reveal that it is a cold-based glacier, its surface temperature remains below 0°C throughout the year, and ablation occurs mostly by sublimation. Ablation creates ice cliffs punctuated of pluricentimetric whitish, tapered crystals embedded in the ice (Fig.1b, c). By Raman and chemistry, they proved to be gypsum, covered by micrometric crystals of jarosite, halotrichite and native sulfur. The euhedral morphology of these soft minerals indicates that they are neoformed and have not been transported in the ice. This is supported by the absence of gypsum crystals in ice cores drilled through the glacier. We infer that the crystallization thus occurred at the glacier surface during ice sublimation and does not involve liquid water. To distinguish this original salt formation process from the more common evaporites, we name these minerals "sublimites". Though this formation process is uncommon and generates minor quantities of sulfates on Earth, it may be dominant on other bodies in the Solar System where sublimation is effective. Examples of planetary sublimites may include gypsum on the North Polar Cap of Mars (Massé et al., 2012), and other sulfates on icy moons where sublimation has been observed (Howard et al., 2008).

  16. Analysis of observed surface ozone in the dry season over Eastern Thailand during 1997-2012

    Science.gov (United States)

    Assareh, Nosha; Prabamroong, Thayukorn; Manomaiphiboon, Kasemsan; Theramongkol, Phunsak; Leungsakul, Sirakarn; Mitrjit, Nawarat; Rachiwong, Jintarat

    2016-09-01

    This study analyzed observed surface ozone (O3) in the dry season over a long-term period of 1997-2012 for the eastern region of Thailand and incorporated several technical tools or methods in investigating different aspects of O3. The focus was the urbanized and industrialized coastal areas recently recognized as most O3-polluted areas. It was found that O3 is intensified most in the dry-season months when meteorological conditions are favorable to O3 development. The diurnal variations of O3 and its precursors show the general patterns of urban background. From observational O3 isopleth diagrams and morning ratios of non-methane volatile organic compounds (NMVOC) and nitrogen oxides (NOx), the chemical regime of O3 formation was identified as VOC-sensitive, and the degree of VOC sensitivity tends to increase over the years, suggesting emission control on VOC to be suitable for O3 management. Both total oxidant analysis and back-trajectory modeling (together with K-means clustering) indicate the potential role of regional transport or influence in enhancing surface O3 level over the study areas. A meteorological adjustment with generalized linear modeling was performed to statistically exclude meteorological effects on the variability of O3. Local air-mass recirculation factor was included in the modeling to support the coastal application. The derived trends in O3 based on the meteorological adjustment were found to be significantly positive using a Mann-Kendall test with block bootstrapping.

  17. Organic zinc supplementation in the dry season in nelore bulls and its effect on spermiogram

    Directory of Open Access Journals (Sweden)

    Bruna Cardin Hofig Ramos

    2014-02-01

    Full Text Available The objective of this study was to evaluate the effect of a diet supplementation with 500mg organic zinc (Zn on sperm morphological characteristics (mass motility, individual motility, and sperm livability as well as minor and major sperm defects in Nelore bulls during the dry season of 2010, the pluviometric precipitation during the experimental period which occurred from April to October, was 69mm from April to August. Thirty-six bulls were selected and divided into two groups of 18 bulls. They were fed the supplemented diet for 180 days. The animals in the first group (G1 were supplemented with an average of 48,89ppm/kg MS Zn, and the animals in the second group (G2 were supplemented with 115,09ppm/ kg DM Zn. Data was analyzed with Minitab 13.0. The results of the morphological characteristic of sperm G1 and G2 were higher at 180 days compared to Day zero, especially in vigor and mass motility, with only statistically significant difference in each group, not differentiating between groups. The organic zinc did not affect the morphological characteristic of sperm in Nellore bulls in the dry season.

  18. The influence of soils on heterotrophic respiration exerts a strong control on net ecosystem productivity in seasonally dry Amazonian forests

    Directory of Open Access Journals (Sweden)

    J. R. Melton

    2014-08-01

    Full Text Available Net ecosystem productivity of carbon (NEP in seasonally dry forests of the Amazon varies greatly between sites with similar precipitation patterns. Correctly modeling the NEP seasonality with terrestrial ecosystem models has proven difficult. Previous modelling studies have mostly advocated incorporating processes that act to reduce water stress on gross primary productivity (GPP during the dry season such as including deep soils and roots, plant-mediated hydraulic redistribution of soil moisture, and increased dry season leaf litter generation which reduces leaf age and thus increases photosynthetic capacity. Recent observations, however, indicate that seasonality in heterotrophic respiration also contributes to the observed seasonal cycle of NEP. Here, we use the dynamic vegetation model CLASS-CTEM – without deep soils or roots, hydraulic redistribution of soil moisture or increased dry season litter generation – at two Large-Scale Biosphere–Atmosphere Experiment (LBA sites (Tapajós km 83 and Jarú Reserve. These LBA sites exhibit opposite seasonal NEP cycles despite similar meteorological conditions. Our simulations are able to reproduce the observed NEP seasonality at both sites. Simulated GPP, heterotrophic respiration, latent and sensible heat fluxes, litter fall rate, soil moisture and temperature, and basic vegetation state are also compared with available observation-based estimates which provide confidence that the model overall behaves realistically at the two sites. Our results indicate that appropriately representing the influence of soil texture and depth, through soil moisture, on seasonal patterns of GPP and, especially, heterotrophic respiration is important to correctly simulating NEP seasonality.

  19. Living at the threshold: where does the neotropical phytoseiid mite Typhlodromalus aripo survive the dry season?

    Science.gov (United States)

    Zundel, Christine; Hanna, Rachid; Scheidegger, Urs; Nagel, Peter

    2007-01-01

    The establishment of the neotropical predatory mite Typhlodromalus aripo in sub-Saharan Africa has resulted in broadly successful biological control of the cassava green mite Mononychellus tanajoa throughout the cassava belt of Africa. In some mid-altitude areas and drier lowland savannahs of sub-Saharan Africa, which are characterized by cool or hot long (> or =5 months) dry seasons, the predator disappears from its habitat in the cassava apex during the dry season and reappears after the onset of rains. It is not known, however, where the predator remains during this time period. In this study, we conducted a field enclosure experiment of cassava plants with the objectives to determine if (a) T. aripo survives at very low densities in the apex, if (b) it survives in the soil or leaf litter below the cassava plant, and if (c) it recolonizes the cassava plant from the surrounding vegetation. Towards the end of the dry season, when the predators had disappeared from all cassava plants included in the experiment, five treatments were applied: (1) plants without enclosure; (2) plants with enclosure; (3) plants with enclosure, apices removed; (4) plants with enclosure, glue barrier around stem; and (5) plants kept free of T. aripo, without enclosure. Predator (re)appearance on cassava apices was monitored non-destructively at weekly intervals and was expressed as the proportion of plants with at least one apex with T. aripo per total number of plants of the treatment. The predators reappeared first on the plants of the treatments (1), (2), and (4). With a time lag of 7-8 weeks, the predators appeared also on the plants of the treatments (3) and (5). The time pattern of the predator's (re)appearance in the cassava apex of the different treatments suggests that (a) T. aripo survives the dry season in very low densities in the cassava apex; this result is supported by an assessment of the efficiency of non-destructive visual in-field apex inspections which proved that

  20. Simulating Plant Water Stress and Phenology in Seasonally Dry Tropical Forests: Plant Hydraulics and Trait-Driven Trade-Offs

    Science.gov (United States)

    Xu, X.; Medvigy, D.; Powers, J. S.; Becknell, J. M.

    2014-12-01

    Seasonally dry tropical forests account for over 40% of the forested area in tropical and subtropical regions. Previous studies suggest that seasonal water stress is one main driver of phenology and related vegetation dynamics in seasonally dry tropical forests. Species that coexist in seasonally dry tropical forests have different plant traits, experience different degrees of plant water stress and show distinctive phenological patterns. However, the observed diversity in plant phenology and related vegetation dynamics is poorly represented in current dynamic vegetation models. In this study, we employ a new modeling approach to enhance our model skills in seasonally dry tropical forests. First, we implement a new plant hydraulic module under the framework of a state-of-the-art dynamic vegetation model, Ecosystem Demography 2 (ED2). Second, we link plant water stress with several key coordinated plant traits. Unlike previous models, the updated ED2 does not prescribe leaf phenology (deciduous or evergreen) and plant water stress is not determined by empirical water stress factors or by soil moisture alone. Instead, the model tracks more mechanistic indicators of plant water stress like leaf water potential, accounts for different abilities to tolerate water stress among plant functional types and predicts dry season leaf deciduousness and related vegetation dynamics. The updated model is then tested with in-situ meteorological data and long-term ecological observations. We also perform numerical experiments to explore the possible biases of ignoring the observed diversity in seasonally dry tropical forests. We find that (i) variations of several key plant traits (specific leaf area, wood density, turgor loss point and rooting depth) can account for the observed distinctive phenological patterns as well as inter-annual variations in vegetation growth among species. (ii) Ignoring the trait-driven trade-offs and diversity in seasonality would introduce significant

  1. Diversity in plant hydraulic traits explains seasonal and inter-annual variations of vegetation dynamics in seasonally dry tropical forests.

    Science.gov (United States)

    Xu, Xiangtao; Medvigy, David; Powers, Jennifer S; Becknell, Justin M; Guan, Kaiyu

    2016-10-01

    We assessed whether diversity in plant hydraulic traits can explain the observed diversity in plant responses to water stress in seasonally dry tropical forests (SDTFs). The Ecosystem Demography model 2 (ED2) was updated with a trait-driven mechanistic plant hydraulic module, as well as novel drought-phenology and plant water stress schemes. Four plant functional types were parameterized on the basis of meta-analysis of plant hydraulic traits. Simulations from both the original and the updated ED2 were evaluated against 5 yr of field data from a Costa Rican SDTF site and remote-sensing data over Central America. The updated model generated realistic plant hydraulic dynamics, such as leaf water potential and stem sap flow. Compared with the original ED2, predictions from our novel trait-driven model matched better with observed growth, phenology and their variations among functional groups. Most notably, the original ED2 produced unrealistically small leaf area index (LAI) and underestimated cumulative leaf litter. Both of these biases were corrected by the updated model. The updated model was also better able to simulate spatial patterns of LAI dynamics in Central America. Plant hydraulic traits are intercorrelated in SDTFs. Mechanistic incorporation of plant hydraulic traits is necessary for the simulation of spatiotemporal patterns of vegetation dynamics in SDTFs in vegetation models.

  2. Cold-season patterns of reserve and soluble carbohydrates in sugar maple and ice-damaged trees of two age classes following drought

    Science.gov (United States)

    B. L. Wong; K. L. Baggett; A. H. Rye

    2009-01-01

    This study examines the effects of summer drought on the composition and profiles of cold-season reserve and soluble carbohydrates in sugar maple (Acer saccharum Marsh.) trees (50-100 years old or ~200 years old) in which the crowns were nondamaged or damaged by the 1998 ice storm. The overall cold season reserve...

  3. Calcium addition at the Hubbard Brook Experimental Forest increases the capacity for stress tolerance and carbon capture in red spruce (Picea rubens) trees during the cold season

    Science.gov (United States)

    Paul G. Schaberg; Rakesh Minocha; Stephanie Long; Joshua M. Halman; Gary J. Hawley; Christopher. Eagar

    2011-01-01

    Red spruce (Picea rubens Sarg.) trees are uniquely vulnerable to foliar freezing injury during the cold season (fall and winter), but are also capable of photosynthetic activity if temperatures moderate. To evaluate the influence of calcium (Ca) addition on the physiology of red spruce during the cold season, we measured concentrations of foliar...

  4. Infestation of Caliothrips phaseoli (Thysanoptera: Thripidae) on Bean Cultivars Grown in the Winter, Rainy, and Dry Seasons in Brazil.

    Science.gov (United States)

    Boiça Júnior, Arlindo Leal; Costa, Eduardo Neves; De Souza, Bruno Henrique Sardinha; Da Silva, Anderson Gonçalves; Chiorato, Alisson Fernando

    2015-08-01

    The present study aimed to identify common bean (Phaseolus vulgaris L.) cultivars less susceptible to Caliothrips phaseoli (Hood) in different growing seasons, to evaluate whether climatic conditions influence plant resistance to C. phaseoli infestation, and to investigate the preferred plant part for insect feeding. Eighteen common bean cultivars were evaluated in the winter season, and 19 cultivars were assessed in the rainy and dry seasons, under field conditions in the municipality of Jaboticabal, state of São Paulo, Brazil. Infestation of C. phaseoli nymphs in the upper and lower parts of the beans plants was recorded at weekly intervals from 25 days after plant emergence (DAE) to 60 DAE. In the winter season, the cultivars 'IAC Galante,' 'IAC Centauro,' 'IAC Carioca Eté,' and 'IAC Formoso' had significantly lower number of thrips than the cultivar 'IAC Diplomata.' In the rainy season, the cultivars 'IAC Harmonia' and 'IPR Siriri' had the lowest thrips infestation, differing from the cultivars 'BRS Pontal' and 'IAC Una.' The bean cultivars were equally susceptible to C. phaseoli in the dry season. The results suggest that C. phaseoli nymphs prefer to infest leaves of the lower part of bean plants, like most generalist herbivorous insects. In the winter and dry seasons, the highest thrips infestation was observed at 60 DAE, while in the rainy season, it was recorded from 32 to 46 DAE. Overall, C. phaseoli infestation on bean cultivars was not influenced by either temperature, relative humidity, or rainfall.

  5. Trace Metal Pollution From Traffic in Denizli-Turkey During Dry Season

    Institute of Scientific and Technical Information of China (English)

    UMIT DIVRIKLI; DURALI MENDIL; MUSTAFA TUZEN; MUSTAFA SOYLAK; LATIF ELCI

    2006-01-01

    To determine the metal contents of date palm (Pheonix dactylifera) samples in dry season from Denizli-Turkey for investigation of heavy metal-polluted traffic. Method The levels of iron, copper, zinc, lead, cadmium,nickel, chromium, and manganese ions in the leaves of thirty five date palm (Pheonix dactylifera) samples collected from various levels of traffic in the streets of Denizli-Turkey were determined by graphite furnace or flame atomic absorption spectrometry. The wet, dry, and microwave digestion procedures for the date palm (Pheonix dactylifera) leaves were compared.The accuracy of the digestion procedures was checked using a standard reference material (IAEA-336 Lichen, SRM). Results Microwave digestion procedure for the leaves was preferred because it was more proper with respect to both time and recovery than dry and wet digestion. The levels of the heavy metal ions investigated were the highest on the samples from high traffic level. Also correlations between metal levels and traffic volume for all the metals were investigated. Conclusion In the light of our findings, the date palm (Phoenix dactylifera) leaves are suitable as a biomonitor for atmospheric heavy metal-polluted traffic. Significant correlations can be obtained between traffic levels and heavy metal concentrations.

  6. Studies on wels catfish (Silurus glanis development during cold season as an auxiliary species in sturgeon recirculated aquaculture systems

    Directory of Open Access Journals (Sweden)

    Radu Muscalu

    2010-12-01

    Full Text Available The research had the purpose to establish if the wels catfish is suitable for growing in closedrecirculated system designed for sturgeon farming, because during the cold season the system does notneed to reach high temperatures such as for other fish species. Our studies showed that the wels catfishcan survive during the cold season from a recirculated system, and furthermore they accept feeds attemperatures as low as 17°C, and even have a slight body weight increase during this season. The welscatfish entered the spring in our experiment at a mean body weight of 72.5 grams, while the wels catfishfrom semi-intensive system after wintering in earthern ponds entered the winter at a mean body weighof 30 grams. Our experiments also studied the effect of stocking density on fish development in theseconditions.

  7. An assessment of El Niño and La Niña impacts focused on monthly and seasonal rainfall and extreme dry/precipitation events in mountain regions of Colombia and México

    Science.gov (United States)

    Pinilla Herrera, María Carolina; Andrés Pinzón Correa, Carlos

    2016-03-01

    The influence of El Niño and La Niña on monthly and seasonal rainfall over mountain landscapes in Colombia and México was assessed based on the Oceanic Niño Index (ONI). A statistical analysis was develop to compare the extreme dry/precipitation events between El Niño, La Niña and Neutral episodes. For both areas, it was observed that El Niño and La Niña episodes are associated with important increases or decreases in rainfall. However, Neutral episodes showed the highest occurrence of extreme precipitation/dry events. For a better understanding of the impact of El Niño and La Niña on seasonal precipitation, we did a compound and a GIS analyses to define the high/low probability of above, below or normal seasonal precipitation under El Niño, La Niña and cold/warm Neutral episodes. In San Vicente, Colombia the below-normal seasonal rainfall was identified during El Niño and Neutral episodes in the dry season JJA. In this same municipality we also found above-normal seasonal rainfall during La Niña and Neutral episodes, especially in the dry season DJF. In Tancítaro México the below-normal seasonal rainfall was identified during La Niña winters (DJF) and El Niño summers (JJA), the above-normal seasonal rainfall was found during La Niña summers (JJA) and El Niño winters (DJF).

  8. The role of climate and environmental variables in structuring bird assemblages in the Seasonally Dry Tropical Forests (SDTFs)

    Science.gov (United States)

    Gonçalves, Gabriela Silva Ribeiro; Cerqueira, Pablo Vieira; Brasil, Leandro Schlemmer; Santos, Marcos Pérsio Dantas

    2017-01-01

    Understanding the processes that influence species diversity is still a challenge in ecological studies. However, there are two main theories to discuss this topic, the niche theory and the neutral theory. Our objective was to understand the importance of environmental and spatial processes in structuring bird communities within the hydrological seasons in dry forest areas in northeastern Brazil. The study was conducted in two National Parks, the Serra da Capivara and Serra das Confusões National Parks, where 36 areas were sampled in different seasons (dry, dry/rainy transition, rainy, rainy/dry transition), in 2012 and 2013. We found with our results that bird species richness is higher in the rainy season and lower during the dry season, indicating a strong influence of seasonality, a pattern also found for environmental heterogeneity. Richness was explained by local environmental factors, while species composition was explained by environmental and spatial factors. The environmental factors were more important in explaining variations in composition. Climate change predictions have currently pointed out frequent drought events and a rise in global temperature by 2050, which would lead to changes in species behavior and to increasing desertification in some regions, including the Caatinga. In addition, the high deforestation rates and the low level of representativeness of the Caatinga in the conservation units negatively affects bird communities. This scenario has demonstrated how climatic factors affect individuals, and, therefore, should be the starting point for conservation initiatives to be developed in xeric environments. PMID:28441412

  9. The Potential Allocation for Dry Season Crop-Area Planning, the Huai Luang Operation and Maintenance Project, Thailand

    Directory of Open Access Journals (Sweden)

    Pisan Ubonpiphat

    2014-03-01

    Full Text Available This study comprised optimization process for finding crop-area planning in dry-season and the application of optimization program using Linear Programming (LP to solve optimal area planned in dry-season. The study area was applied to left and right main canal system of Huai Luang Reservoir, Thailand. The calculation data obtained from dry year (2003, normal year (2001 and wet year (1996. The analysis created condition objective function and constraint functions. The constraints consisted of the constriction of area characteristic, irrigation water requirement, water availability, cropping-area of each Irrigation Zones, capacity of Left and Right Main Canal System of Huai Luang Reservoir, capacity of canal in Irrigation Zones and cropping pattern alternatives. The results found that LP was functioned for finding cropping and setting area for dry-season planning. The comparison results from alternative plans found that the areas obtained from first alternative plan which undivided area, it was founded that optimal area was less than that obtained from the second alternative which divided area about 12.62% 11.35% and 4.87% for dry year, normal year and wet year, respectively. Hence, allocation potential for dry season crop-area planning were 4,531.20 ha, 6,574.08 ha and 7,116.64 ha for dry year, normal year and wet year, respectively. The results from equations could made graph of relationship between the areas obtained from equation and the sum of water capacity in Huai Luang reservoir, it found that the graph was functioned well to optimize cropping and setting area for dry-season planning in the further year. The results of testing in 2011/2012 also showed that the difference of the solutions obtained by graph and the cropping area results in main canal system was 4.53%.

  10. Vegetation and Lepidoptera in Seasonally Dry Tropical Forests. Community structure along climate zones, forest succession and seasonality in the Southern Yucatán, Mexico

    NARCIS (Netherlands)

    Essens, T.; Leyequien, E.; Pozo, C.

    2010-01-01

    Seasonally dry tropical forests are worldwide recognized as important ecosystems for biodiversity conservation. Increasing agricultural activities (e.g., slash-and-burn agriculture) leads to a heterogeneous landscape matrix; and as ecological succession takes over in abandoned fields, plant and anim

  11. 2010 Dry and 2009 - 2010 Wet Season Branchiopod Survey Report, Site 300

    Energy Technology Data Exchange (ETDEWEB)

    Dexter, W

    2011-03-14

    Lawrence Livermore National Laboratory (LLNL) requested that Condor Country Consulting, Inc. (CCCI) perform wet season surveys and manage the dry season sampling for listed branchiopods in two ponded locations within the Site 300 Experimental Test Site. Site 300 is located in Alameda and San Joaquin Counties, located between the Cities of Livermore and Tracy. The two pool locations have been identified for possible amphibian enhancement activities in support of the Compensation Plan for impacts tied to the Building 850 soil clean-up project. The Building 850 project design resulted in formal consultation with the U.S. Fish and Wildlife Service (USFWS) as an amendment (File 81420-2009-F-0235) to the site-wide Biological Opinion (BO) (File 1-1-02-F-0062) in the spring of 2009 and requires mitigation for the California tiger salamander (AMCA, Ambystoma californiense) and California red-legged frog (CRLF, Rana draytonii) habitat loss. Both pools contain breeding AMCA, but do not produce metamorphs due to limited hydroperiod. The pool to the southeast (Pool BC-FS-2) is the preferred site for amphibian enhancement activities, and the wetland to northwest (Pool OA-FS-1) is the alternate location for enhancement. However, prior to enhancement, LLNL has been directed by USFWS (BO Conservation Measure 17 iii) to 'conduct USFWS protocol-level branchiopod surveys to determine whether listed brachiopod species are present within the compensation area.' CCCI conducted surveys for listed branchiopods in the 2009-2010 wet season to determine the presence of federally-listed branchiopods at the two pools (previous surveys with negative findings were performed by CCCI in 2001-2002 and 2002-2003 onsite). Surveys were conducted to partially satisfy the survey requirements of the USFWS 'Interim Survey Guidelines to Permittees for Recovery Permits under Section 10(a)(1)(A) of the Endangered Species Act for the Listed Vernal Pool Branchiopods' ('Guidelines, USFWS

  12. The numerical investigation of seasonal variation of the cold water mass in the Beibu Gulf and its mechanisms

    Institute of Scientific and Technical Information of China (English)

    CHEN Zhenhua; QIAO Fangli; XIA Changshui; WANG Gang

    2015-01-01

    A wave-tide-circulation coupled model based on the Princeton Ocean Model is established to explore the seasonal variation of the cold water mass in the Beibu Gulf and its mechanisms. The results show that the cold water mass starts forming in March, reaches the maximum strength during June and July, and fades away since October. Strong mixing in winter transports the cold water from sea surface to bottom. The cold water mass remains in the bottom layer as the thermocline strengthens during spring, except for the shallow water where the themocline is broken by strong tidal mixing, which gradually separate the cold water mass from its surrounding warm water. Further analysis on the ocean current and stream function confirms that the cold water mass in the Beibu Gulf is locally developed, with an anticlockwise circulation caused by a strong temperature gradient. Sensitivity experiments reveal that the cold water mass is controlled by the sea surface heat flux, while the terrain and tidal mixing also play important roles.

  13. Transpiration increases during the dry season: patterns of tree water use in eucalypt open-forests of northern Australia.

    Science.gov (United States)

    O'Grady, A. P.; Eamus, D.; Hutley, L. B.

    1999-07-01

    Australian savannas exhibit marked seasonality in precipitation, with more than 90% of the annual total falling between October and May. The dry season is characterized by declining soil water availability and high vapor pressure deficits (up to 2.5 kPa). We used heat pulse technology to measure whole-tree transpiration rates on a daily and seasonal basis for the two dominant eucalypts at a site near Darwin, Australia. Contrary to expectations, transpiration rates were higher during the dry season than during the wet season, largely because of increased evaporative demand and the exploitation of groundwater reserves by the trees. Transpiration rates exhibited a marked hysteresis in relation to vapor pressure deficit, which was more marked in the dry season than in the wet season. This result may be attributable to low soil hydraulic conductivity, or the use of stored stem water, or both. Tree water use was strongly correlated with leaf area and diameter at breast height and there were no differences in transpiration between the species studied. These results are discussed in relation to scaling tree water use to stand water use.

  14. Sub-Seasonal Prediction of the Maritime Continent Rainfall of Wet-Dry Transitional Seasons in the NCEP Climate Forecast Version 2

    Directory of Open Access Journals (Sweden)

    Tuantuan Zhang

    2016-02-01

    Full Text Available This study investigates the characteristics and prediction of the Maritime Continent (MC rainfall for the transitional periods between wet and dry seasons. Several observational data sets and the output from the 45-day hindcast by the U.S. National Centers for Environmental Prediction (NCEP Climate Forecast System version 2 (CFSv2 are used. Results show that the MC experiences a sudden transition from wet season to dry season (WTD around the 27th pentad, and a gradual transition from dry season to wet season (DTW around the 59th pentad. Correspondingly, the westerlies over the equatorial Indian Ocean, the easterlies over the equatorial Pacific Ocean, and the Australia High become weaker, contributing to weakening of the convergence over the MC. The subtropical western Pacific high intensifies and extends northeastward during the WTD. The Mascarene High becomes weaker, an anomalous anticyclonic circulation forms over the northeast of the Philippines, and an anomalous low-level convergence occurs over the western MC during the DTW. The NCEP CFSv2 captures the major features of rainfall and related atmospheric circulation when forecast lead time is less than three weeks for WTD and two weeks for DTW. The model predicts a weaker amplitude of the changes in rainfall and related atmospheric circulation for both WTD and DTW as lead time increases.

  15. Dry season distribution of land crabs, Gecarcinus quadratus (Crustacea: Gecarcinidae), in Corcovado National Park, Costa Rica.

    Science.gov (United States)

    Griffiths, Megan E; Mohammad, Basma A; Vega, Andres

    2007-03-01

    The land crab Gecarcinus quadratus is an engineering species that controls nutrient cycling in tropical forests. Factors regulating their coastal distribution are not fully understood. We quantified land crab distribution during the dry season at Sirena Field Station in Corcovado National Park, Costa Rica, and found that land crab burrow density decreases with increasing distance from the ocean. Leaf litter depth and tree seedling density are negatively correlated with land crab burrow density. Burrows are strongly associated with sand substrate and burrow density is comparatively low in clay substrate. Results suggest that G. quadratus is limited to a narrow coastal zone with sand substrate, and this distribution could have profound effects on plant community structure.

  16. Genetic and environmental effects on a meat spotting defect in seasoned dry-cured ham

    Directory of Open Access Journals (Sweden)

    Giulio Pagnacco

    2011-01-01

    Full Text Available Purpose of this investigation was to determine the nature of a visible spotting defect on the slice of dry-cured ham and assess environmental and genetic causes of this frequent problem. A group of 233 pigs from commercial cross-breeding lines, progeny of ten boars and forty seven sows, was raised in a single herd to obtain the “Italian Heavy Pig”, typically slaughtered at 160 ± 10 kg live weight and older than 9 months of age. A quality evaluation of their right dry-cured hams, seasoned according to the Parma P.D.O. protocol, was undertaken. Each ham was cross-sectioned to obtain a slice of Semimembranosus, Semitendinosus and Biceps Femoris muscles. The focused phenotype was the presence/absence of brownish spots in these muscles, which represent a remarkable meat defect with strong impact on the final sale price. Environmental and management factors were considered in order to evaluate variability related to the phenotype. Animals were raised on two different flooring types (concrete and slatted floor and a Vitamin C diet was also supplemented in the last 45 days before slaughtering to half of the animals. While the pre-planned environmental effects did not show any significant contribution to the total variability of the phenotype, the genetic analysis showed a near to zero value for heritability with a consistent 0.32 repeatability. The proportion of the total phenotypic variance was explained by an important dominance genetic component (0.26 indicating that the technological seasoning process may play a secondary role on the expression of this phenotype.

  17. Study and Test of Cold Storage Heat Recovery Heat Pump Coupled Solar Drying Device

    Directory of Open Access Journals (Sweden)

    Min Li

    2013-05-01

    Full Text Available In this study, we design the recovery of a heat pump combined solar drying device. Then, with this device, drying experiments of aquatic product, tilapia, were conducted, indicating that the newly designed device functions are well in temperature adjusting and controlling performance and showing that drying time is closely related to energy consumption and drying conditions. Heat recovery heat pump combined solar energy drier can improve the drying quality of aquatic products, but also can greatly reduce the drying energy consumption, which provides theoretical support to the design and processing of heat recovery heat pump of refrigeration system coupled solar drying device.

  18. Rubber trees demonstrate a clear retranslocation under seasonal drought and cold stresses

    Directory of Open Access Journals (Sweden)

    Yuwu Li

    2016-12-01

    Full Text Available Having been introduced to the northern edge of Asian tropics, the rubber tree (Hevea brasiliensis has become deciduous in this climate with seasonal drought and cold stresses. To determine its internal nutrient strategy during leaf senescence and deciduous periods, we investigated mature leaf and senescent leaf nutrients, water-soluble soil nutrients and characteristics of soil microbiota in nine different ages of monoculture rubber plantations. Rubber trees demonstrate complicated retranslocation of N, P and K during foliar turnover. Approximately 50.26% of leaf nutrients and 21.47% of soil nutrients were redistributed to the rubber tree body during the leaf senescence and withering stages. However, no significant changes in the structure- or function-related properties of soil microbes were detected. These nutrient retranslocation strategy may be important stress responses. In the nutrient retranslocation process, soil plays a dual role as nutrient supplier and nutrient bank. Soil received the nutrients from abscissed leaves, and also supplied nutrients to trees in the non-growth stage. Nutrient absorption and accumulation began before the leaves started to wither and fall.

  19. Observed cold season changes in a Fennoscandian fell area over the past three decades.

    Science.gov (United States)

    Kivinen, Sonja; Rasmus, Sirpa

    2015-04-01

    We studied trends and variability in snow and climate characteristics in 1978-2012 in the Värriötunturit fell area, northern Finland. Cold season changes were examined using long-term observational data on snow depths, meteorological data, large-scale climate indices, and reindeer herders' experiences with difficult snow conditions. Snow depths declined, and temperatures increased significantly over the study period, with the largest changes observed in October-December and in April. Snow depths decreased particularly in forests at lower altitudes but not in treeless areas at higher altitudes. Interannual variability (but not the trends) in snow depths could be partially linked to large-scale climate indices. A majority of difficult reindeer grazing conditions were related to deep snow in the winter or spring. Our observations suggest that shortened duration of snow cover may facilitate reindeer grazing, whereas potentially more frequent formation of ice layers and mold growth on pastures in the future is disadvantageous for reindeer husbandry.

  20. Study and Test of Cold Storage Heat Recovery Heat Pump Coupled Solar Drying Device

    OpenAIRE

    Min Li; Xiao-Qiang Jiang; Bao-Chuan Wu

    2013-01-01

    In this study, we design the recovery of a heat pump combined solar drying device. Then, with this device, drying experiments of aquatic product, tilapia, were conducted, indicating that the newly designed device functions are well in temperature adjusting and controlling performance and showing that drying time is closely related to energy consumption and drying conditions. Heat recovery heat pump combined solar energy drier can improve the drying quality of aquatic products, but also can gr...

  1. Crude glycerin in diets for Nelore heifers on pasture in dry season

    Directory of Open Access Journals (Sweden)

    Gonçalo Mesquita da Silva

    2015-02-01

    Full Text Available This study aimed to evaluate the inclusion of crude glycerin (CG in the diet of Nellore heifers grazing Brachiaria brizantha during the dry season, on nutrients intake and digestibility, performance, reproductive efficiency and economic viability. Sixty Nelore heifers with initial average weight of 285.89 ± 18.74 kg and approximately 19 ± 2 months of age, were distributed in a completely randomized design with five diets containing 0.0; 4.0; 8.0; 12.0 and 16.0% of CG inclusion in the diet. The average dry matter (DM daily intake showed decreasing linear effect (P 0.05, with a mean value of 50.93%. The average daily gain (ADG of heifers showed decreasing linear effect (P0.05 by dietary inclusion of GB, with average values of 75% and 1.29 doses pregnant-¹, respectively. The economic viability indicators were not positive in the short and medium term. Supplements for over 0.7% of the PC in animals maintained in Brachiaria brizantha with low nutritional quality, it is not recommended to include GB, since its inclusion in any level reduced around 15% weight gain. However, depending on the cost of coproduct, it can be includes up to 16% in the diet, even considering this drop in performance.

  2. Seasonality of Tropical Dry Forests and its Sensitivity to Climate Change

    Science.gov (United States)

    Xu, X.; Medvigy, D.; Powers, J. S.; Becknell, J. M.

    2013-12-01

    Tropical dry forests (TDFs) are characterized by an annual dry season of 3-6 months duration. Although TDFs account for nearly 42% by area of total tropical vegetation, their representation in current dynamic vegetation models has rarely been challenged by ground-based observations. In this study, we assimilate several unique field datasets and MODIS-derived Leaf Area Index (LAI) into the Ecosystem Demography Model version 2 (ED2). The field measurements were taken at 18 forested stands in Costa Rica including annual tree-level censuses, species-level leaf trait, monthly measurements of stand litterfall and soil properties since 2008. These measurements were used to develop plant functional types (PFTs) suitable for modeling TDFs, especially in terms of their allometry, phenology, and growth rates. The model was then forced with Coupled Model Intercomparison Project Phase 5 (CMIP5) climate projections for Central America to quantify the response and sensitivity of vegetation dynamics to different radiative forcing scenarios. We expect that this study will improve our knowledge of TDFs, including their phenology and sensitivity future climate change, and also has implications for TDF carbon dynamics, energy budgets and hydrological cycling.

  3. Intermediate tree cover can maximize groundwater recharge in the seasonally dry tropics

    Science.gov (United States)

    Ilstedt, U.; Bargués Tobella, A.; Bazié, H. R.; Bayala, J.; Verbeeten, E.; Nyberg, G.; Sanou, J.; Benegas, L.; Murdiyarso, D.; Laudon, H.; Sheil, D.; Malmer, A.

    2016-02-01

    Water scarcity contributes to the poverty of around one-third of the world’s people. Despite many benefits, tree planting in dry regions is often discouraged by concerns that trees reduce water availability. Yet relevant studies from the tropics are scarce, and the impacts of intermediate tree cover remain unexplored. We developed and tested an optimum tree cover theory in which groundwater recharge is maximized at an intermediate tree density. Below this optimal tree density the benefits from any additional trees on water percolation exceed their extra water use, leading to increased groundwater recharge, while above the optimum the opposite occurs. Our results, based on groundwater budgets calibrated with measurements of drainage and transpiration in a cultivated woodland in West Africa, demonstrate that groundwater recharge was maximised at intermediate tree densities. In contrast to the prevailing view, we therefore find that moderate tree cover can increase groundwater recharge, and that tree planting and various tree management options can improve groundwater resources. We evaluate the necessary conditions for these results to hold and suggest that they are likely to be common in the seasonally dry tropics, offering potential for widespread tree establishment and increased benefits for hundreds of millions of people.

  4. Distribution of Cenozoic plant relicts in China explained by drought in dry season.

    Science.gov (United States)

    Huang, Yongjiang; Jacques, Frédéric M B; Su, Tao; Ferguson, David K; Tang, Hui; Chen, Wenyun; Zhou, Zhekun

    2015-09-15

    Cenozoic plant relicts are those groups that were once widespread in the Northern Hemisphere but are now restricted to some small isolated areas as a result of drastic climatic changes. They are good proxies to study how plants respond to climatic changes since their modern climatic requirements are known. Herein we look at the modern distribution of 65 palaeoendemic genera in China and compare it with the Chinese climatic pattern, in order to find a link between the plant distribution and climate. Central China and Taiwan Island are shown to be diversity centres of Cenozoic relict genera, consistent with the fact that these two regions have a shorter dry season with comparatively humid autumn and spring in China. Species distribution models indicate that the precipitation parameters are the most important variables to explain the distribution of relict genera. The Cenozoic wide-scale distribution of relict plants in the Northern Hemisphere is therefore considered to be linked to the widespread humid climate at that time, and the subsequent contraction of their distributional ranges was probably caused by the drying trend along with global cooling.

  5. Seasonal patterns of leaf gas exchange and water relations in dry rain forest trees of contrasting leaf phenology.

    Science.gov (United States)

    Choat, Brendan; Ball, Marilyn C; Luly, Jon G; Donnelly, Christine F; Holtum, Joseph A M

    2006-05-01

    Diurnal and seasonal patterns of leaf gas exchange and water relations were examined in tree species of contrasting leaf phenology growing in a seasonally dry tropical rain forest in north-eastern Australia. Two drought-deciduous species, Brachychiton australis (Schott and Endl.) A. Terracc. and Cochlospermum gillivraei Benth., and two evergreen species, Alphitonia excelsa (Fenzal) Benth. and Austromyrtus bidwillii (Benth.) Burret. were studied. The deciduous species had higher specific leaf areas and maximum photosynthetic rates per leaf dry mass in the wet season than the evergreens. During the transition from wet season to dry season, total canopy area was reduced by 70-90% in the deciduous species and stomatal conductance (g(s)) and assimilation rate (A) were markedly lower in the remaining leaves. Deciduous species maintained daytime leaf water potentials (Psi(L)) at close to or above wet season values by a combination of stomatal regulation and reduction in leaf area. Thus, the timing of leaf drop in deciduous species was not associated with large negative values of daytime Psi(L) (greater than -1.6 MPa) or predawn Psi(L) (greater than -1.0 MPa). The deciduous species appeared sensitive to small perturbations in soil and leaf water status that signalled the onset of drought. The evergreen species were less sensitive to the onset of drought and g(s) values were not significantly lower during the transitional period. In the dry season, the evergreen species maintained their canopies despite increasing water-stress; however, unlike Eucalyptus species from northern Australian savannas, A and g(s) were significantly lower than wet season values.

  6. Seasonal trends of dry and bulk concentration of nitrogen compounds over a rain forest in Ghana

    Directory of Open Access Journals (Sweden)

    F. Fattore

    2013-09-01

    Full Text Available African tropical forests of the equatorial belt might receive significant input of extra nitrogen derived from biomass burning occurring in the north savanna belt and transported equator wards by NE winds. In order to test this hypothesis an experiment was set up in a tropical rain forest in the National park of Ankasa (Ghana aiming at: quantifying magnitude and seasonal variability of concentrations of N compounds, present as gas and aerosol (dry nitrogen or in the rainfall (bulk nitrogen, over the studied forest; relating their seasonal variability to trends of local and regional winds and rainfall and to variations of fire events in the region. Three Delta systems, implemented for monthly measurements of NO2, were mounted over a tower at 45 m height, 20 m above forest canopy to sample gas (NH3, NO2, HNO3, HCl, SO2 and aerosol (NH4+, NO3−, and several ions, together with three tanks for bulk rainfall collection (to analyze NH4+, NO3− and ion concentration. The tower was provided with a sonic anemometer to estimate local wind data. The experiment started in October 2011 and data up to October 2012 are presented. To interpret the observed seasonal trends of measured compounds, local and regional meteo data and regional satellite fire data were analyzed. The concentration of N compounds significantly increased from December to April, during the drier period, peaking in December-February when North Eastern winds (Harmattan were moving dry air masses over the West central African region and the inter tropical convergence zone (ITCZ was at its minimum latitude over the equator. This period also coincided with peaks of fire in the whole region. On the contrary, N concentration in gas, aerosol and rain decreased from May to October when prevalent winds arrived from the sea (South-East, during the Monsoon period. Both ionic compositions of rain and analysis of local wind direction showed a significant and continuous presence of see-breeze at site

  7. Effect of elevated [CO2] and nutrient management on wet and dry season rice production in subtropical India

    Institute of Scientific and Technical Information of China (English)

    Sushree Sagarika Satapathy; Dillip Kumar Swain; Surendranath Pasupalak; Pratap Bhanu Singh Bhadoria

    2015-01-01

    The present experiment was conducted to evaluate the effect of elevated [CO2] with varying nutrient management on rice–rice production system. The experiment was conducted in the open field and inside open-top chambers (OTCs) of ambient [CO2] (≈390μmol L−1) and elevated [CO2] environment (25%above ambient) during wet and dry seasons in 2011–2013 at Kharagpur, India. The nutrient management included recommended doses of N, P, and K as chemical fertilizer (CF), integration of chemical and organic sources, and application of increased (25%higher) doses of CF. The higher [CO2] level in the OTC increased aboveground biomass but marginally decreased filled grains per panicle and grain yield of rice, compared to the ambient environment. However, crop root biomass was increased significantly under elevated [CO2]. With respect to nutrient management, increasing the dose of CF increased grain yield significantly in both seasons. At the recommended dose of nutrients, integrated nutrient management was comparable to CF in the wet season, but significantly inferior in the dry season, in its effect on growth and yield of rice. The [CO2] elevation in OTC led to a marginal increase in organic C and available P content of soil, but a decrease in available N content. It was concluded that increased doses of nutrients via integration of chemical and organic sources in the wet season and chemical sources alone in the dry season will minimize the adverse effect of future climate on rice production in subtropical India.

  8. Unstable malaria in Sudan: the influence of the dry season. Malaria in areas of unstable and seasonal transmission. Lessons from Daraweesh

    DEFF Research Database (Denmark)

    Theander, T G

    1999-01-01

    -parasite relationships in an area characterized by unstable and seasonal malaria of low transmission intensity. The work was performed in the village Daraweesh located in north-eastern Sudan 16 km from Gedaref town. The climate of the region is characterized by well-defined wet and dry periods with a short rainy season...... blood-stage infections cause clinical disease. Together these findings suggest that many new infections are controlled immunologically and that individuals aged over 30 years are more successful in controlling infections than are teenagers. Parasite strains collected in Daraweesh are genotypically...

  9. Seasonal evolution of the Yellow Sea Cold Water Mass and its interactions with ambient hydrodynamic system

    Science.gov (United States)

    Li, Jianchao; Li, Guangxue; Xu, Jishang; Dong, Ping; Qiao, Lulu; Liu, Shidong; Sun, Pingkuo; Fan, Zhisong

    2016-09-01

    The Yellow Sea Cold Water Mass (YSCWM) is an important component of the hydrodynamic system in the South Yellow Sea (SYS). However, its intricate interactions with the ambient flows over long time scales are not fully understood. This paper presents the analysis of the data set obtained from a seabed-mounted Acoustic Doppler Current Profiler (ADCP) deployed for nearly 1 year in the western SYS. It allowed us to study the evolution of YSCWM, including the seasonal changes of tidal currents, near-inertial oscillations (NIOs), and the wind-driven currents due to typhoons and winter storms. Strong NIOs were found near the bottom of mixed layer and in the pycnocline with nearly opposite current directions, with maximum velocity of nearly 20 cm·s-1 in summer. The YSCWM can also inhibit the direct downward energy transport in the water column due to typhoons. Conversely, the hydrodynamic system also feeds back to influence the change of YSCWM. A large current shear (S) of 20 cm·s-1·m-1 is generated near the top of pycnocline. Generally, the intensity and depth of the pycnocline determine S's magnitude and vertical location, respectively. Based on the monthly averaged density profile data, the Richardson number and wavelet analysis, the NIOs are considered to be capable of inducing predominant shear instability around the pycnocline. However, the NIOs are not strong enough to influence the lower YSCWM. In addition, in autumn, each fortnightly spring tide corresponds with a bottom temperature increase of nearly 2°C, indicating that tidal currents are the leading hydrodynamic driving force to decline the YSCWM.

  10. Cold season Africa-Asia multidecadal teleconnection pattern and its relation to the Atlantic multidecadal variability

    Science.gov (United States)

    Sun, Cheng; Li, Jianping; Ding, Ruiqiang; Jin, Ze

    2016-08-01

    A prominent teleconnection pattern of multidecadal variability of cold season (November to April) upper-level atmospheric circulation over North Africa and Eurasia (NA-EA) is revealed by empirical orthogonal function analysis of the Twentieth Century Reanalysis data. This teleconnection pattern is characterized by an eastward propagating wave train with a zonal wavenumber of 5-6 between 20° and 40°N, extending from the northwest coast of Africa to East Asia, and thus is referred to as the Africa-Asia multidecadal teleconnection pattern (AAMT). One-point correlation maps show that the teleconnectivity of AAMT is strong and further demonstrate the existence of the AAMT. The AAMT shapes the spatial structure of multidecadal change in atmospheric circulation over the NA-EA region, and in particular the AAMT pattern and associated fields show similar structures to the change occurring around the early 1960s. A strong in-phase relationship is observed between the AAMT and Atlantic multidecadal variability (AMV) and this connection is mainly due to Rossby wave dynamics. Barotropic modeling results suggest that the upper-level Rossby wave source generated by the AMV can excite the AAMT wave train, and Rossby wave ray tracing analysis further highlights the role of the Asian jet stream in guiding the wave train to East Asia. The AAMT acts as an atmospheric bridge conveying the influence of AMV onto the downstream multidecadal climate variability. The AMV is closely related to the coordinated change in surface and tropospheric air temperatures over Northwest Africa, the Arabian Peninsula and Central China, which may result from the adiabatic expansion/compression of air associated with the AAMT.

  11. Cold season Africa-Asia multidecadal teleconnection pattern and its relation to the Atlantic multidecadal variability

    Science.gov (United States)

    Sun, Cheng; Li, Jianping; Ding, Ruiqiang; Jin, Ze

    2017-06-01

    A prominent teleconnection pattern of multidecadal variability of cold season (November to April) upper-level atmospheric circulation over North Africa and Eurasia (NA-EA) is revealed by empirical orthogonal function analysis of the Twentieth Century Reanalysis data. This teleconnection pattern is characterized by an eastward propagating wave train with a zonal wavenumber of 5-6 between 20° and 40°N, extending from the northwest coast of Africa to East Asia, and thus is referred to as the Africa-Asia multidecadal teleconnection pattern (AAMT). One-point correlation maps show that the teleconnectivity of AAMT is strong and further demonstrate the existence of the AAMT. The AAMT shapes the spatial structure of multidecadal change in atmospheric circulation over the NA-EA region, and in particular the AAMT pattern and associated fields show similar structures to the change occurring around the early 1960s. A strong in-phase relationship is observed between the AAMT and Atlantic multidecadal variability (AMV) and this connection is mainly due to Rossby wave dynamics. Barotropic modeling results suggest that the upper-level Rossby wave source generated by the AMV can excite the AAMT wave train, and Rossby wave ray tracing analysis further highlights the role of the Asian jet stream in guiding the wave train to East Asia. The AAMT acts as an atmospheric bridge conveying the influence of AMV onto the downstream multidecadal climate variability. The AMV is closely related to the coordinated change in surface and tropospheric air temperatures over Northwest Africa, the Arabian Peninsula and Central China, which may result from the adiabatic expansion/compression of air associated with the AAMT.

  12. Effects of Protein Supplementation During the Dry Season on Feed Intake and the Performance of Borgou Cows in Benin Republic

    NARCIS (Netherlands)

    Alkoiret, I.T.; Akouedegni, G.C.; Toukourou, Y.; Bosma, R.H.; Mensah, G.A.

    2011-01-01

    The purpose of this study was to assess the effect of dry season protein supplementation of Borgou cows on feed intake, milk production, body weight and calves growth performance. Animals (24 cows) were all given a basal diet of straw bush ad libitum. Cows of 1st group (8 cows in each group) were co

  13. Coordinated airborne, spaceborne, and ground-based measurements of massive thick aerosol layers during the dry season in southern Africa

    NARCIS (Netherlands)

    Schmid, B.; Redemann, J.; Russell, P.B.; Hobbs, P.V.; Hlavka, D.L.; McGill, M.J.; Holben, B.N.; Welton, E.J.; Campbell, J.R.; Torres, O.; Kahn, R.A.; Diner, D.J.; Helmlinger, M.C.; Chu, D.A.; Robles-Gonzalez, C.; Leeuw, G.de

    2003-01-01

    During the dry season airborne campaign of the Southern African Regional Science Initiative (SAFARI 2000), coordinated observations were made of massive thick aerosol layers. These layers were often dominated by aerosols from biomass burning. We report on airborne Sun photometer measurements of aero

  14. Coordinated airborne, spaceborne, and ground-based measurements of massive thick aerosol layers during the dry season in southern Africa

    NARCIS (Netherlands)

    Schmid, B.; Redemann, J.; Russell, P.B.; Hobbs, P.V.; Hlavka, D.L.; McGill, M.J.; Holben, B.N.; Welton, E.J.; Campbell, J.R.; Torres, O.; Kahn, R.A.; Diner, D.J.; Helmlinger, M.C.; Chu, D.A.; Robles-Gonzalez, C.; Leeuw, G.de

    2003-01-01

    During the dry season airborne campaign of the Southern African Regional Science Initiative (SAFARI 2000), coordinated observations were made of massive thick aerosol layers. These layers were often dominated by aerosols from biomass burning. We report on airborne Sun photometer measurements of

  15. Cytotoxic and genotoxic assessment of surface water from São Paulo State, Brazil, during the rainy and dry seasons.

    Science.gov (United States)

    Salles, Fernanda Junqueira; de Toledo, Maria Cecília Barbosa; César, Ana Cristina Gobbo; Ferreira, Gabriel Martins; Barbério, Agnes

    2016-05-01

    The aim of this study was to determine if the cytotoxic and genotoxic responses of Allium cepa are effective biomarkers of harmful effects caused by polluted river water and if changes in the responses reflect seasonality in the harmful effects. Samples were collected in the dry season (August 2011 and 2012) and rainy season (February 2012 and 2013) at sampling points on the Jaguari River and the Ribeirão Lavapés, in Brazil. Allium cepa bulbs were exposed to the samples, to positive controls (15 µg/L methyl methanesulfonate), and to negative controls (tap water). Three root tips from each bulb were then stained using the Feulgen reaction, then the micronucleus frequency, the mitotic index, and mitotic anomalies were measured. The total number of anomalies (stickiness, c-mitosis, multipolarity, chromosome bridges, and unidentified anomalies) in the rainy season (8.61 ± 3.65) and dry season (7.07 ± 2.96) were significantly different (U = 11.31, p = 0.04). Toxicity, indicated by the formation of micronuclei and the mitotic index, was higher in the February 2012 samples than in the August 2012 samples. The mean manganese concentration (0.13 mg/L) in the rainy season samples was higher than the maximum concentration permitted by the Brazilian National Environmental Council (<0.1 mg/L) and the manganese concentrations positively correlated with chromosomal aberration induction (p = 0.01, r = 0.69). In conclusion, the rainy season samples were more toxic than the dry season samples. This was probably related to rain water carrying compounds with potentially negative impacts into the rivers. These findings highlight the importance of biomonitoring studies and of treating wastewater in urban areas.

  16. Hadley cell dynamics of a cold and virtually dry Snowball Earth atmosphere

    Science.gov (United States)

    Voigt, Aiko; Held, Isaac; Marotzke, Jochem

    2010-05-01

    We use the full-physics atmospheric general circulation model ECHAM5 to investigate a cold and virtually dry Snowball Earth atmosphere that results from specifying sea ice as the surface boundary condition everywhere, corresponding to a frozen aquaplanet, while keeping total solar irradiance at its present-day value of 1365 Wm-2. The aim of this study is the investigation of the zonal-mean circulation of a Snowball Earth atmosphere, which, due to missing moisture, might constitute an ideal though yet unexplored testbed for theories of atmospheric dynamics. To ease comparison with theories, incoming solar insolation follows permanent equinox conditions with disabled diurnal cycle. The meridional circulation consists of a thermally direct cell extending from the equator to 45 N/S with ascent in the equatorial region, and a weak thermally indirect cell with descent between 45 and 65 N/S and ascent in the polar region. The former cell corresponds to the present-day Earth's Hadley cell, while the latter can be viewed as an eddy-driven Ferrell cell; the present-day Earth's direct polar cell is missing. The Hadley cell itself is subdivided into a vigorous cell confined to the troposphere and a weak deep cell reaching well into the stratosphere. The dynamics of the vigorous Snowball Earth Hadley cell differ substantially from the dynamics of the present-day Hadley cell. The zonal momentum balance shows that in the poleward branch of the vigorous Hadley cell, mean flow meridional advection of absolute vorticity is not only balanced by eddy momentum flux convergence but also by vertical diffusion. Inside the poleward branch, eddies are more important in the upper part and vertical diffusion is more important in the lower part. Vertical diffusion also contributes to the meridional momentum balance as it decelerates the vigorous Hadley cell by downgradient momentum mixing between its poleward and equatorward branch. Zonal winds, therefore, are not in thermal wind balance in

  17. Characterization of water quality and suspended sediment during cold-season flows, warm-season flows, and stormflows in the Fountain and Monument Creek watersheds, Colorado, 2007–2015

    Science.gov (United States)

    Miller, Lisa D.; Stogner, Sr., Robert W.

    2017-09-01

    From 2007 through 2015, the U.S. Geological Survey, in cooperation with Colorado Springs City Engineering, conducted a study in the Fountain and Monument Creek watersheds, Colorado, to characterize surface-water quality and suspended-sediment conditions for three different streamflow regimes with an emphasis on characterizing water quality during storm runoff. Data collected during this study were used to evaluate the effects of stormflows and wastewater-treatment effluent discharge on Fountain and Monument Creeks in the Colorado Springs, Colorado, area. Water-quality samples were collected at 2 sites on Upper Fountain Creek, 2 sites on Monument Creek, 3 sites on Lower Fountain Creek, and 13 tributary sites during 3 flow regimes: cold-season flow (November–April), warm-season flow (May–October), and stormflow from 2007 through 2015. During 2015, additional samples were collected and analyzed for Escherichia coli (E. coli) during dry weather conditions at 41 sites, located in E. coli impaired stream reaches, to help identify source areas and scope of the impairment.Concentrations of E. coli, total arsenic, and dissolved copper, selenium, and zinc in surface-water samples were compared to Colorado in-stream standards. Stormflow concentrations of E. coli frequently exceeded the recreational use standard of 126 colonies per 100 milliliters at main-stem and tributary sites by more than an order of magnitude. Even though median E. coli concentrations in warm-season flow samples were lower than median concentrations in storm-flow samples, the water quality standard for E. coli was still exceeded at most main-stem sites and many tributary sites during warm-season flows. Six samples (three warm-season flow and three stormflow samples) collected from Upper Fountain Creek, upstream from the confluence of Monument Creek, and two stormflow samples collected from Lower Fountain Creek, downstream from the confluence with Monument Creek, exceeded the acute water

  18. Serum Copper and Haematological Values of Sheep of Different Physiological Stages in the Dry and Wet Seasons of Central Trinidad

    Science.gov (United States)

    Mohammed, A.; Campbell, M.; Youssef, F. G.

    2014-01-01

    A study was conducted to determine serum copper (Cu) concentrations and hematological values of 174 sheep from four medium sized farms, pertaining to physiological stage, in the late dry and late wet seasons of Central Trinidad. Serum Cu was significantly lower in the dry than in the wet season (P < 0.001) with a corresponding high percentage of samples with low Cu levels in the former. 31% of dry nonpregnant sheep exhibited a nonregenerative anaemia. Also, hemoglobin and packed cell volume values varied (P < 0.001) including lymphocyte (P < 0.01) counts, among growing animals compared with other physiological stages. Significant variations also occurred among neutrophil (P < 0.05) and eosinophil (P < 0.05) values in sheep. Highest haemoglobin and packed cell volume, white blood cell counts, and lymphocyte values in growing sheep compared with other stages were probably age related. PMID:24895542

  19. Serum Copper and Haematological Values of Sheep of Different Physiological Stages in the Dry and Wet Seasons of Central Trinidad

    Directory of Open Access Journals (Sweden)

    A. Mohammed

    2014-01-01

    Full Text Available A study was conducted to determine serum copper (Cu concentrations and hematological values of 174 sheep from four medium sized farms, pertaining to physiological stage, in the late dry and late wet seasons of Central Trinidad. Serum Cu was significantly lower in the dry than in the wet season (P<0.001 with a corresponding high percentage of samples with low Cu levels in the former. 31% of dry nonpregnant sheep exhibited a nonregenerative anaemia. Also, hemoglobin and packed cell volume values varied (P<0.001 including lymphocyte (P<0.01 counts, among growing animals compared with other physiological stages. Significant variations also occurred among neutrophil (P<0.05 and eosinophil (P<0.05 values in sheep. Highest haemoglobin and packed cell volume, white blood cell counts, and lymphocyte values in growing sheep compared with other stages were probably age related.

  20. What drives cold-related excess mortality in a south Asian tropical monsoon climate-season vs. temperatures and diurnal temperature changes

    Science.gov (United States)

    Burkart, Katrin; Kinney, Patrick L.

    2016-12-01

    Despite the tropical climate which is characterized by generally high temperatures and persistent mild temperatures during the winter season, Bangladesh, along with many other tropical countries, experiences strong winter and cold-related excess mortality. The objective of this paper was to analyse the nature of these cold effects and understand the role of season vs. temperature and diurnal changes in temperature. For approaching these questions, we applied different Poisson regression models. Temperature as well as diurnal temperature range (DTR) were considered as predictor variables. Different approaches to seasonality adjustment were evaluated and special consideration was given to seasonal differences in atmospheric effects. Our findings show that while seasonality adjustment affected the magnitude of cold effects, cold-related mortality persisted regardless the adjustment approach. Strongest effects of low temperatures were observed at the same day (lag 1) with an increase of 1.7% (95% CI = 0.86-2.54%) per 1 °C decrease in temperature during the winter season. Diurnal temperature affected mortality with increasing levels at higher ranges. Mortality increased with 0.97% (95% CI = 0.17-1.75%) when looking at the entire season, but effects of DTR were not significant during winter when running a seasonal model. Different from effects observed in the mid-latitudes, cold effects in Bangladesh occurred on a very short time scale highlighting the role of temperature versus season. Insufficient adaptation with regard to housing and clothing might lead to such cold-related increases in mortality despite rather moderate temperature values. Although the study did not demonstrate an effect of DTR during the cold season, the strong correlation with (minimum) temperature might cause a multicollinearity problem and effects are difficult to attribute to one driver.

  1. Vegetation and Lepidoptera in Seasonally Dry Tropical Forests. Community structure along climate zones, forest succession and seasonality in the Southern Yucatán, Mexico

    OpenAIRE

    Essens, T.; Leyequien, E.; Pozo, C. (Cándido)

    2010-01-01

    Seasonally dry tropical forests are worldwide recognized as important ecosystems for biodiversity conservation. Increasing agricultural activities (e.g., slash-and-burn agriculture) leads to a heterogeneous landscape matrix; and as ecological succession takes over in abandoned fields, plant and animal communities endure shifts in species richness and composition. This book presents the analysis on plant and Lepidoptera (caterpillar) communities and their species turnover along forest successi...

  2. Different supplents for finishing of Nellore cattle on deferred Brachiaria decumbens pasture during the dry season

    Directory of Open Access Journals (Sweden)

    Antonio Tadeu de Andrade

    2015-07-01

    Full Text Available This study evaluated the effect of four types of supplement on the finishing of Nellore cattle on deferred Brachiaria decumbens pasture during the dry season. Sixty-four castrated Nellore males with an age of approximately 34 months and initial body weight (BW ranging from 360 to 380 kg were divided into 16 animals per treatment in a completely randomized design. The treatments consisted of four types of pasture supplement: deferred Brachiaria decumbens pasture + energy protein mineral salt (SuEPM used as control; deferred Brachiaria decumbens pasture + urea + cottonseed meal (28% CP + ground corn grain (SuCo; deferred Brachiaria decumbens pasture + urea + cottonseed meal (28% CP + citrus pulp (SuCPu; deferred Brachiaria decumbens pasture + urea + cottonseed meal (28% CP + soy hull (SuSH. The pasture was deferred for 170 days and provided 3,482 kg DM/ha of forage, permitting a stocking rate of 1.56 AU/ha (DM intake of 2.25% BW and 50% pasture efficiency. The animals received the supplement ad libitum in the SuEPM treatment and as % BW in the other treatments from July to October. The animals were slaughtered at a minimum BW of 457 kg. The following variables were evaluated: final weight, weight gain during the period (WG, average daily gain (ADG, hot carcass weight (HCW, and hot carcass yield (HCY. With respect to final weight, the supplement in the SuCo, SuCPu and SuSH treatments permitted a greater supply of nutrients and the animals therefore exhibited better performance (P<0.05 compared to the SuEPM treatment (mean of 478.68 vs 412.62 kg. The same effect was observed for the other parameters studied. Analysis of WG and ADG showed that SuSH was superior to the SuCo and SuCPu treatments (P<0.05 due to the increased offer of concentrate and SuEPM was inferior to the other treatments. Higher HCW (260.05 kg and HCY (53.92% were obtained with treatment SuSH as a result of greater performance. Supplementation of cattle during the dry period on

  3. Photoprotection of evergreen and drought-deciduous tree leaves to overcome the dry season in monsoonal tropical dry forests in Thailand.

    Science.gov (United States)

    Ishida, Atsushi; Yamazaki, Jun-Ya; Harayama, Hisanori; Yazaki, Kenichi; Ladpala, Phanumard; Nakano, Takashi; Adachi, Minaco; Yoshimura, Kenichi; Panuthai, Samreong; Staporn, Duriya; Maeda, Takahisa; Maruta, Emiko; Diloksumpun, Sapit; Puangchit, Ladawan

    2014-01-01

    In tropical dry forests, uppermost-canopy leaves of evergreen trees possess the ability to use water more conservatively compared with drought-deciduous trees, which may result from significant differences in the photoprotective mechanisms between functional types. We examined the seasonal variations in leaf gas exchange, chlorophyll fluorescence and the amounts of photosynthetic pigments within lamina of the uppermost-canopy leaves of three drought-deciduous trees (Vitex peduncularis Wall., Xylia xylocarpa (Roxb.) W. Theob., Shorea siamensis Miq.), a semi-deciduous tree (Irvingia malayana Miq.) and two evergreen trees (Hopea ferrea Lanessan and Syzygium cumini (L.) Skeels) in Thailand. Area-based maximum carbon assimilation rates (Amax) decreased during the dry season, except in S. siamensis. The electron transport rate (ETR) remained unchanged in deciduous trees, but decreased during the dry season in evergreen and semi-deciduous trees. In the principal component analysis, the first axis (Axis 1) accounted for 44.3% of the total variation and distinguished deciduous from evergreen trees. Along Axis 1, evergreen trees were characterized by a high Stern-Volmer non-photochemical quenching coefficient (NPQ), high xanthophyll cycle pigments/chlorophyll and a high de-epoxidation state of the xanthophyll cycle, whereas the deciduous trees were characterized by a high ETR, a high quantum yield of PSII (ΦPSII = (Fm(') -F)/Fm(')) and a high mass-based Amax under high-light conditions. These findings indicate that drought-deciduous trees showing less conservative water use tend to dissipate a large proportion of electron flow through photosynthesis or alternative pathways. In contrast, the evergreens showed more conservative water use, reduced Amax and ETR and enhanced NPQ and xanthophyll cycle pigments/chlorophyll during the dry season, indicating that down-regulated photosynthesis with enhanced thermal dissipation of excess light energy played an important role in

  4. DRY-SEASON VARIABILITY IN SUSPENDED SEDIMENT CONCENTRATIONS IN THE SOUTH PASSAGE OF THE CHANGJIANG ESTUARY

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    This paper reports the results of continuous monitoring of turbidity, water depth, salinity (using an Optical Backscatter Sensor (OBS)), and current velocity (using a Current meter (SLC9-2)) in the South Passage of the Changjiang Estuary over a spring-neap period in February 2003 (dry season).The turbidity measured via OBS was closely correlated with the suspended sediment concentration (SSC), which was highly variable. Over the study period, the SSC in the middle layer ranged from 110 to 1400 mg/l. The minimum SSC occurred during a late ebb tide, and the maximum SSC occurred during a late flood tide. On average, the SSC was 1.5 times higher during flood tide than during ebb tide. Vertically within the water column, SSC increased downward, with the ratio of SSC measured near the bed to that measured at the surface ranging from 1.90 to 18.3. The temporal variability in SSC is jointly governed by tides and wind-induced waves, whereas the vertical variability in SSC is attributed to the effect of gravity and vertical water circulation.

  5. Effect of feed supplements on dry season milk yield and profitability of crossbred cows in Honduras.

    Science.gov (United States)

    Reiber, Christoph; Peters, Michael; Möhring, Jens; Schultze-Kraft, Rainer

    2013-06-01

    The contribution of dry season silage feeding on daily milk yield (MY) and dairying profitability in terms of income over feed cost (IOFC) was evaluated in dual-purpose cattle production systems in Honduras. MY records of 34 farms from two milk collection centres were collected over a 2-year period. Farms were surveyed to obtain information on the type, quantity and cost of supplemented feed, breed type and number of lactating cows in each month. Farms were classified in silage farms (SF, with a short silage supplementation period), non-silage farms (NSF) and prototype farms (PF, with an extended silage supplementation period). Data were analysed using descriptive statistics and a linear mixed model approach. PF had significantly higher MY than SF and NSF but, due to higher expenses for both concentrate and silage, similar IOFC compared to NSF. SF had similar MY but lower IOFC compared to NSF, due to higher feed expenses. The effect of silage feeding, particularly maize silage, on MY was significant and superior to that of other forage supplements. Silage supplementation contributed to the highest MY and IOFC on farms with crossbred cows of >62.5 % Bos taurus and to the second highest profitability on farms with >87.5 % Bos indicus share. It is concluded that silage can play an important role in drought-constrained areas of the tropics and can contribute to profitable dairying, irrespective of breed.

  6. Data-driven behavioural characterization of dry-season groundwater-level variation in Maharashtra, India

    Indian Academy of Sciences (India)

    Rahul Gokhale; Milind Sohoni

    2015-06-01

    This paper looks at the crucial issue of dry-season groundwater-availability in the state of Maharashtra, India. We look at the two key hydro-climatological measurements which are used to implement ground-water policy in the state, viz., water levels in 5000+ observation wells across the state and aggregate rainfall data. We see that there is substantial variation in groundwater levels within and across the years in most wells. We argue that for a large number of these observation well locations, aggregate rainfall data is inadequate to model or to predict groundwater levels. For this, we use a novel random rainfall coefficient model for the purpose of modelling the effect of rainfall in a composite setting where extraction and changing land-use data is unknown. The observed high variance of this coefficient points to significant variations in groundwater levels, which may only be explained by unmeasured anthropogenic factors. Next, we see that the uncertainty in actual groundwater levels along with scarcity are two distinct features of groundwater availability and will elicit different behaviours from the typical user. Finally, we recommend that quantitative groundwater assessment protocols of the state should move to incorporating data from which extraction and land-use may be modelled. We believe this is one of the first studies where large spatio-temporal scale data gathered by state agencies have been analysed for scientific adequacy.

  7. Levels of multiple supplements or nitrogen salt for beef heifers in pasture during the dry season

    Directory of Open Access Journals (Sweden)

    Ériton Egidio Lisboa Valente

    2011-09-01

    Full Text Available The study assessed performance, microbial protein synthesis, intake and digestibility of nutrients by beef heifers receiving levels of multiple supplements or nitrogen salt, in a self-controlled intake, on pasture, during the dry season. Thirty-five beef heifers, from 6 to 9 months of age and average initial body weight of 203.4 + 4.5 kg, were used. Study factors were: control - mineral mixture; nitrogen salt - 50% of urea + mineral mixture, at proportion of 1:1, and 50% of corn (75% of crude protein; levels of multiple supplementation - multiple supplements with different percentages of intake controller mixture (urea + mineral mixture, at the proportion of 1:1, corn and soybean meal (45% of crude protein. Supplement consumptions observed were: 115, 173, 572 and 1214 g/animal/day for animals fed on nitrogen salt, low, medium and high levels of multiple supplement, respectively. Supplemented animals had greater average daily gain, evidencing the positive linear effect of the levels of multiple supplementation on average daily gain. Overall, there were no significant differences between average daily gain of animals fed on multiple supplements or nitrogen salt. Supplementation increased the intake and digestibility of nutrients, except for digestibility of neutral detergent fiber, although the intake of digested neutral detergent fiber increased. Supplementation increased the production of microbial nitrogen as well as nitrogen losses in urine, although the quantity of nitrogen assimilated by bacteria, proportionally to intake, was higher. Supplementation improves nutritional parameters and weight gain.

  8. Airborne measurements of carbonaceous aerosols in southern Africa during the dry, biomass burning season

    Energy Technology Data Exchange (ETDEWEB)

    Kirchstetter, Thomas W.; Novakov, T.; Hobbs, Peter V.; Magi, Brian

    2002-06-17

    Particulate matter collected aboard the University of Washington's Convair-580 research aircraft over southern Africa during the dry, biomass burning season was analyzed for total carbon, organic carbon, and black carbon contents using thermal and optical methods. Samples were collected in smoke plumes of burning savanna and in regional haze. A known artifact, produced by the adsorption of organic gases on the quartz filter substrates used to collect the particulate matter samples, comprised a significant portion of the total carbon collected. Consequently, conclusions derived from the data are greatly dependent on whether or not organic carbon concentrations are corrected for this artifact. For example, the estimated aerosol co-albedo (1 - single scattering albedo), which is a measure of aerosol absorption, of the biomass smoke samples is 60 percent larger using corrected organic carbon concentrations. Thus, the corrected data imply that the biomass smoke is 60 percent more absorbing than do the uncorrected data. The black carbon to (corrected) organic carbon mass ratio (BC/OC) of smoke plume samples (0.18/2610.06) is lower than that of samples collected in the regional haze (0.25/2610.08). The difference may be due to mixing of biomass smoke with background air characterized by a higher BC/OC ratio. A simple source apportionment indicates that biomass smoke contributes about three-quarters of the aerosol burden in the regional haze, while other sources (e.g., fossil fuel burning) contribute the remainder.

  9. Species diversity and regeneration of old-growth seasonally dry Shorea robusta forests following gap formation

    Institute of Scientific and Technical Information of China (English)

    Indra Prasad Sapkota; Mulualem Tigabu; Per Christer Odén

    2009-01-01

    Diversity and regeneration of woody species were investigated in two ecological niches viz. gap and intact vegetation in old-growth seasonally dry Shorea robusta (Gaertn. f.) forests in Nepal. We also related varieties of diversity measures and regeneration attributes to gap characteristics. Stem density of tree and shrub components is higher in the gap than in the intact vegetation. Seedling densities of S. robusta and Terminalia alata (B. Heyne ex Roth.) are higher in the gap than in the intact vegetation, while contrary result is observed for T. bellirica (Gaertn. ex Roxb.) and Syzigium cumini (L. Skeels) in term of seedling density. The complement of Simpson index, Evenness index, and species-individual ratio in the seedling layer are lower in the gap than the intact vegetation. Gap size can explain species richness and species establishment rate. Gaps created by multiple tree falls in different years have higher seedling density of S. robusta than gaps created by single and/or multiple tree falls in the same year. In conclusion, gaps maintain species diversity by increasing seedling density, and favor regeneration of Sal forests. In addition to gap size, other gap attributes also affect species diversity and regeneration.

  10. WET AND DRY SEASON ECOSYSTEM LEVEL FLUXES OF ISOPRENE AND MONOTERPENES FROM A SOUTHEAST ASIAN SECONDARY FOREST AND RUBBER TREE PLANTATION

    Science.gov (United States)

    Canopy scale fluxes of isoprene and monoterpenes were investigated in both wet and dry seasons above a rubber tree (Hevea brasiliensis)/secondary tropical forest in the Yunnan province of southwestern China. Drought conditions were unusually high during the dry season experiment....

  11. How Does Dung Beetle (Coleoptera: Scarabaeidae) Diversity Vary Along a Rainy Season in a Tropical Dry Forest?

    Science.gov (United States)

    Novais, Samuel M. A.; Evangelista, Lucas A.; Reis-Júnior, Ronaldo; Neves, Frederico S.

    2016-01-01

    Dung beetle community dynamics are determined by regional rainfall patterns. However, little is known about the temporal dynamics of these communities in tropical dry forests (TDFs). This study was designed to test the following predictions: 1) Peak diversity of dung beetle species occurs early in the wet season, with a decrease in diversity (α and β) and abundance throughout the season; 2) Nestedness is the primary process determining β-diversity, with species sampled in the middle and the end of the wet season representing subsets of the early wet season community. Dung beetles were collected in a TDF in the northern Minas Gerais state, Brazil over three sampling events (December 2009, February and April 2010). We sampled 2,018 dung beetles belonging to 39 species and distributed among 15 genera. Scarabaeinae α-diversity and abundance were highest in December and equivalent between February and April, while β-diversity among plots increased along the wet season. The importance of nestedness and species turnover varies between pairs of sample periods as the main process of temporal β-diversity. Most species collected in the middle and end of the wet season were found in greater abundance in early wet season. Thus, the dung beetle community becomes more homogeneous at the beginning of the wet season, and as the season advances, higher resource scarcity limits population size, which likely results in a smaller foraging range, increasing β-diversity. Our results demonstrate high synchronism between the dung beetle life cycle and seasonality of environmental conditions throughout the wet season in a TDF, where the onset of rains determines adult emergence for most species. PMID:27620555

  12. Temporal dynamics of airborne fungi in Havana (Cuba) during dry and rainy seasons: influence of meteorological parameters

    Science.gov (United States)

    Almaguer, Michel; Aira, María-Jesús; Rodríguez-Rajo, F. Javier; Rojas, Teresa I.

    2014-09-01

    The aim of this paper was to determine for first time the influence of the main meteorological parameters on the atmospheric fungal spore concentration in Havana (Cuba). This city is characterized by a subtropical climate with two different marked annual rainfall seasons during the year: a "dry season" and a "rainy season". A nonviable volumetric methodology (Lanzoni VPPS-2000 sampler) was used to sample airborne spores. The total number of spores counted during the 2 years of study was 293,594, belonging to 30 different genera and five spore types. Relative humidity was the meteorological parameter most influencing the atmospheric concentration of the spores, mainly during the rainy season of the year. Winds coming from the SW direction also increased the spore concentration in the air. In terms of spore intradiurnal variation we found three different patterns: morning maximum values for Cladosporium, night peaks for Coprinus and Leptosphaeria, and uniform behavior throughout the whole day for Aspergillus/ Penicillium."

  13. Spectra and vegetation index variations in moss soil crust in different seasons, and in wet and dry conditions

    Science.gov (United States)

    Fang, Shibo; Yu, Weiguo; Qi, Yue

    2015-06-01

    Similar to vascular plants, non-vascular plant mosses have different periods of seasonal growth. There has been little research on the spectral variations of moss soil crust (MSC) over different growth periods. Few studies have paid attention to the difference in spectral characteristics between wet MSC that is photosynthesizing and dry MSC in suspended metabolism. The dissimilarity of MSC spectra in wet and dry conditions during different seasons needs further investigation. In this study, the spectral reflectance of wet MSC, dry MSC and the dominant vascular plant (Artemisia) were characterized in situ during the summer (July) and autumn (September). The variations in the normalized difference vegetation index (NDVI), biological soil crust index (BSCI) and CI (crust index) in different seasons and under different soil moisture conditions were also analyzed. It was found that (1) the spectral characteristics of both wet and dry MSCs varied seasonally; (2) the spectral features of wet MSC appear similar to those of the vascular plant, Artemisia, whether in summer or autumn; (3) both in summer and in autumn, much higher NDVI values were acquired for wet than for dry MSC (0.6 ∼ 0.7 vs. 0.3 ∼ 0.4 units), which may lead to misinterpretation of vegetation dynamics in the presence of MSC and with the variations in rainfall occurring in arid and semi-arid zones; and (4) the BSCI and CI values of wet MSC were close to that of Artemisia in both summer and autumn, indicating that BSCI and CI could barely differentiate between the wet MSC and Artemisia.

  14. Effect of elevated [CO2] and nutrient management on wet and dry season rice production in subtropical India

    Institute of Scientific and Technical Information of China (English)

    Sushree Sagarika Satapathy; Dillip Kumar Swain; Surendranath Pasupalak; Pratap Bhanu Singh Bhadoria

    2015-01-01

    The present experiment was conducted to evaluate the effect of elevated [CO2] with varying nutrient management on rice–rice production system. The experiment was conducted in the open field and inside open-top chambers(OTCs) of ambient [CO2](≈ 390 μmol L-1) and elevated [CO2] environment(25% above ambient) during wet and dry seasons in 2011–2013at Kharagpur, India. The nutrient management included recommended doses of N, P, and K as chemical fertilizer(CF), integration of chemical and organic sources, and application of increased(25% higher) doses of CF. The higher [CO2] level in the OTC increased aboveground biomass but marginally decreased filled grains per panicle and grain yield of rice, compared to the ambient environment. However, crop root biomass was increased significantly under elevated [CO2]. With respect to nutrient management, increasing the dose of CF increased grain yield significantly in both seasons. At the recommended dose of nutrients, integrated nutrient management was comparable to CF in the wet season, but significantly inferior in the dry season, in its effect on growth and yield of rice. The [CO2] elevation in OTC led to a marginal increase in organic C and available P content of soil, but a decrease in available N content. It was concluded that increased doses of nutrients via integration of chemical and organic sources in the wet season and chemical sources alone in the dry season will minimize the adverse effect of future climate on rice production in subtropical India.

  15. Vertical structure of aerosols and water vapor over West Africa during the African monsoon dry season

    Directory of Open Access Journals (Sweden)

    S.-W. Kim

    2009-10-01

    Full Text Available We present observations of tropospheric aerosol and water vapor transport over West Africa and the associated meteorological conditions during the AMMA SOP-0 dry season experiment, which was conducted in West Africa in January–February 2006. This study combines data from ultra-light aircraft (ULA-based lidar, airborne in-situ aerosol and gas measurements, standard meteorological measurements, satellite-based aerosol measurements, airmass trajectories, and radiosonde measurements. At Niamey (13.5° N, 2.2° E the prevailing surface wind (i.e. Harmattan was from the northeast bringing dry dusty air from the Sahara desert. High concentrations of mineral dust aerosol were typically observed from the surface to 1.5 or 2 km associated with the Saharan airmasses. At higher altitudes the prevailing wind veered to the south or southeast bringing relatively warm and humid airmasses from the biomass burning regions to the Sahel (<10° N. These elevated layers had high concentrations of biomass burning aerosol and were typically observed between altitudes of 2–5 km. Meteorological analyses show these airmasses were advected upwards over the biomass burning regions through ascent in Inter-Tropical Discontinuity (ITD zone. Aerosol vertical profiles obtained from the space-based lidar CALIOP onboard CALIPSO during January 2007 also showed the presence of dust particles (particle depolarization (δ~30%, lidar Ångström exponent (LAE<0, aerosol backscatter to extinction ratio (BER: 0.026~0.028 sr−1 at low levels (<1.5 km and biomass burning smoke aerosol (δ<10%, LAE: 0.6~1.1, BER: 0.015~0.018 sr−1 between 2 and 5 km. CALIOP data indicated that these distinct continental dust and biomass burning aerosol layers likely mixed as they advected further south over the tropical Atlantic Ocean, as indicated an intermediate values of δ (10~17%, LAE (0.16~0.18 and BER (0.0021~0.0022 sr−1.

  16. Using earth observation-based dry season NDVI trends for assessment of changes in tree cover in the Sahel

    DEFF Research Database (Denmark)

    Horion, Stéphanie Marie Anne F; Fensholt, Rasmus; Tagesson, Håkan Torbern

    2014-01-01

    satellite sensors: Système Pour l'Observation de la Terre (SPOT)-VEGETATION (VGT), Terra Moderate Resolution Imaging Spectroradiometer (MODIS), and the Advanced Very High Resolution Radiometer (AVHRR) Global Inventory Modeling and Mapping Studies (GIMMS) dataset. To evaluate the reliability of using NDVImin...... low-resolution satellite time series were found to be uncorrelated to dry grass residues from the preceding growing season and to seasonal fire frequency and timing over most of the Sahel (88%), suggesting that NDVImin can serve as a proxy for assessing changes in tree cover. Good agreement (R2= 0...

  17. Semen variables and sperm membrane protein profile of Saanen bucks ( Capra hircus) in dry and rainy seasons of the northeastern Brazil (3°S)

    Science.gov (United States)

    van Tilburg, M. F.; Salles, M. G. F.; Silva, M. M.; Moreira, R. A.; Moreno, F. B.; Monteiro-Moreira, A. C. O.; Martins, J. A. M.; Cândido, M. J. D.; Araújo, A. A.; Moura, A. A. A.

    2015-05-01

    The Saanen is a highly productive breed, and for this reason, it has been raised in Brazil, but mostly under climate conditions completely different from where the breed originated. The objective of this study was to investigate variations in semen parameters and sperm membrane proteins from Saanen bucks ( n = 7) raised in Northeastern Brazil, during dry season (September, October, and November) and rainy season (March, April, and May). We showed that during the dry season, sperm motility, concentration, and the percentage of normal sperm decreased as compared to the rainy season. Rectal temperatures of bucks had no significant ( p > 0.05) variations during the dry and rainy seasons. However, temperatures of left and right skin testis were higher ( p < 0.05) during the dry as compared to the rainy season. Expression of three proteins (lysine-specific demethylase 5D, adenosine triphosphate (ATP) synthase subunit d, and radial spoke head protein 9 homolog) in sperm membrane were more intense in rainy season and only one protein (cytosol aminopeptidase) had greater expression in the dry season of the year. Our results show that mechanisms of testicular thermoregulation of Saanen bucks did not prevent a decrease in seminal parameters during the dry season. This deterioration may be related to reduced expression of proteins associated with important functions in sperm membrane.

  18. How dengue vector Aedes albopictus (Diptera: Culicidae survive during the dry season in Dhaka City, Bangladesh?

    Directory of Open Access Journals (Sweden)

    Rajib Chowdhury

    2014-08-01

    Full Text Available Background & objectives: In 2000, a dengue outbreak occurred in Bangladesh that included Dhaka City. Both dengue vectors, Aedes aegypti and Ae. albopictus are present in Bangladesh. Aedes aegypti mosquitoes mainly breed in and around houses and Ae. albopictus is an outside breeder. There are many old trees throughout Dhaka City in different parks, streets and the university campus which may have holes that can contribute as potential breeding habitat for the dengue vector. Therefore, a survey was conducted to investigate the presence of eggs of the dengue vector mosquitoes in treeholes during the dry season in February 2001 to know their contribution on dengue outbreaks. Methods: All treeholes in 10 different localities (parks, streets and university campus of Dhaka City were surveyed. All trees were examined for treeholes up to the height of approximately 3 m and sampled. Debris were collected and packed in poly bags and brought to the laboratory for detailed studies. These were then soaked with tap water to observe egg hatching. The soaked materials were kept up to 20 days covered by a fine mosquito net. After 2-3 days, the eggs started hatching and larvae were separated from the sample for rearing up to IV instar. Results: A total of 245 treeholes were surveyed in 49 identified tree species and 18 unidentified trees. Altogether, 1365 Aedes larvae were found, of which 1096 were Aedes albopictus and 269 were other Aedes species. The largest number of larvae was observed in Delonix regia of Leguminosae family. The number of Aedes albopictus found in the treeholes have perfect positive correlation with the number of other Aedes species. Not a single egg of Aedes aegypti was found in this survey. Interpretation & conclusion: This information will inform public health workers as well as the national control programme to help to solve mosquito borne diseases specially that of dengue. This is critical in planning for vector control operations due to

  19. Bloedite sedimentation in a seasonally dry saline lake (Salada Mediana, Spain)

    Science.gov (United States)

    Mees, Florias; Castañeda, Carmen; Herrero, Juan; Van Ranst, Eric

    2011-06-01

    Salt crusts covering the surface of the Salada Mediana, a seasonally dry saline lake in northern Spain, consist predominantly of bloedite (Na 2Mg(SO 4) 2.4H 2O). Microscopic features of the crust were investigated to understand processes of bloedite sedimentation. This study was combined with satellite and airborne observations, revealing asymmetrical concentric and parallel-linear patterns, related to wind action. Gypsum (CaSO 4.H 2O) and glauberite (Na 2Ca(SO 4) 2) in the calcareous sediments below the crust, and abundant eugsterite (Na 4Ca(SO 4) 3.2H 2O) along the base of the crust, largely formed at a different stage than bloedite. The main part of the crust consists predominantly of coarse-crystalline xenotopic-hypidiotopic bloedite, but fan-like aggregates with downward widening, radial aggregates, surface layers with vertically aligned elongated crystals, and partially epitaxial coatings occur as well. The upper part of the crust is marked by a bloedite-thenardite (Na 2SO 4) association, recording a change in brine composition that is not in agreement with results of modelling of local brine evolution. A thin fine-grained thenardite-dominated surface formed in part by subaqueous settling of crystals, but there are also indications for development by transformation of bloedite. Surface features include fan-like bloedite aggregates with upward widening, formed by bottom growth. Overall, the Salada Mediana crusts record a complex history of bloedite and thenardite precipitation by various processes.

  20. Searching for putative avian malaria vectors in a Seasonally Dry Tropical Forest in Brazil.

    Science.gov (United States)

    Ferreira, Francisco C; Rodrigues, Raquel A; Sato, Yukita; Borges, Magno A Z; Braga, Érika M

    2016-11-16

    Haemosporidian parasites of the genera Plasmodium and Haemoproteus can have detrimental effects on individual birds and populations. Despite recent investigations into the distribution and richness of these parasites and their vertebrate hosts, little is known about their dipteran vectors. The Neotropics has the highest diversity of mosquitoes in the world, but few studies have tried to identify vectors in this area, hampering the understanding of the ecology of avian malaria in the highly diverse Neotropical environments. Shannon traps and active collection were used to capture 27,110 mosquitoes in a Seasonally Dry Tropical Forest in southeastern Brazil, a highly endangered ecosystem. We screened 17,619 mosquito abdomens from 12 different species and several unidentified specimens of Culex, grouped into 1,913 pools, for the presence of haemosporidians. Two pools (out of 459) of the mosquito Mansonia titillans and one pool (out of 29) of Mansonia pseudotitillans were positive for Plasmodium parasites, with the detection of a new parasite lineage in the former species. Detected Plasmodium lineages were distributed in three different clades within the phylogenetic tree revealing that Mansonia mosquitoes are potential vectors of genetically distant parasites. Two pools of Culex spp. (out of 43) were positive for Plasmodium gallinaceum and closely related lineages. We found a higher abundance of these putative vectors in pasture areas, but they were also distributed in areas at intermediate and late successional stages. One pool of the mosquito Psorophora discrucians (out of 173) was positive for Haemoproteus. The occurrence of different Plasmodium lineages in Mansonia mosquitoes indicates that this genus encompasses potential vectors of avian malaria parasites in Brazil, even though we did not find positive thoraces among the samples tested. Additional evidence is required to assign the role of Mansonia mosquitoes in avian malaria transmission and further studies

  1. Water-fat MRI in a hibernator reveals seasonal growth of white and brown adipose tissue without cold exposure.

    Science.gov (United States)

    MacCannell, Amanda; Sinclair, Kevin; Friesen-Waldner, Lannette; McKenzie, Charles A; Staples, James F

    2017-03-21

    Obligate hibernators, such as ground squirrels, display circannual patterns which persist even under constant laboratory conditions, suggesting that they are regulated by endogenous rhythms. Brown adipose tissue (BAT) is important for thermogenesis during periodic arousals from hibernation when core body temperature rises spontaneously from 5 to 37 °C. In most small eutherians BAT growth requires several weeks of cold exposure. We hypothesized that in the thirteen-lined ground squirrel (Ictidomys tridecemlineatus), a hibernator, BAT growth is regulated, in part, by an endogenous rhythm and we predicted that this growth would precede the hibernation season without cold exposure. We tested this prediction using repeated water-fat magnetic resonance imaging over a year, including the hibernation season. Thoracic BAT depots increased in volume from spring through autumn even though animals were housed at ~22 °C. Subsequent cold exposure (5 °C) enlarged the thoracic BAT further. The fat fraction of this tissue fell significantly during the period of peak growth, indicating relative increases in non-triglyceride components, perhaps mitochondria or vasculature. We also found that the proportion of the body consisting of white adipose tissue (WAT) increased steadily from spring through autumn, and fell throughout hibernation, mirroring changes in body mass. Unlike BAT, WAT fat fractions remained constant (near 90%) throughout the year. Future studies will evaluate the significance of photoperiod and cold exposure on the growth of these tissues. We also found tissue with a fat fraction characteristic of BAT in the head near the eyes, a potentially novel discovery that requires further confirmation.

  2. Haematology and behaviour of pullets transported by road and administered with ascorbic acid during the hot-dry season.

    Science.gov (United States)

    Minka, N S; Ayo, J O

    2008-10-01

    The effects of ascorbic acid (AA) on pullets transported by road for 6h during the hot-dry season were investigated. Forty Shika Brown pullets administered orally with AA just before transportation served as experimental, while another 40 pullets given sterile water only served as control. Blood samples analyzed before and after transportation in control pullets showed a decrease (P0.05) from those obtained pre-transportation. The result showed that the transportation was stressful in control pullets. The behavioural activities of the pullets' post-transportation period indicated that AA facilitated the transition of the state of depression that followed excitation back to excitation immediately after transportation. In conclusion, AA administration ameliorated the adverse effect of road transportation stress during the hot-dry season.

  3. Dry Season Evapotranspiration Dynamics over Human-Impacted Landscapes in the Southern Amazon Using the Landsat-Based METRIC Model

    Directory of Open Access Journals (Sweden)

    Kul Khand

    2017-07-01

    Full Text Available Although seasonal and temporal variations in evapotranspiration (ET in Amazonia have been studied based upon flux-tower data and coarse resolution satellite-based models, ET dynamics over human-impacted landscapes are highly uncertain in this region. In this study, we estimate ET rates from critical land cover types over highly fragmented landscapes in the southern Amazon and characterize the ET dynamics during the dry season using the METRIC (Mapping Evapotranspiration at high Resolution with Internalized Calibration model. METRIC, a Landsat-based ET model, that generates spatially continuous ET estimates at a 30 m spatial resolution widely used for agricultural applications, was adapted to the southern Amazon by using the NDVI indexed reference ET fraction (ETrF approach. Compared to flux tower-based ET rates, this approach showed an improved performance on the forest ET estimation over the standard METRIC approach, with R2 = 0.73 from R2 = 0.70 and RMSE reduced from 0.77 mm/day to 0.35 mm/day. We used this approach integrated into the METRIC procedure to estimate ET rates from primary, regenerated, and degraded forests and pasture in Acre, Rondônia, and Mato Grosso, all located in the southern Amazon, during the dry season in 2009. The lowest ET rates occurred in Mato Grosso, the driest region. Acre and Rondônia, both located in the southwestern Amazon, had similar ET rates for all land cover types. Dry season ET rates between primary forest and regenerated forest were similar (p > 0.05 in all sites, ranging between 2.5 and 3.4 mm/day for both forest cover types in the three sites. ET rates from degraded forest in Mato Grosso were significantly lower (p < 0.05 compared to the other forest cover types, with a value of 2.03 mm/day on average. Pasture showed the lowest ET rates during the dry season at all study sites, with the dry season average ET varying from 1.7 mm/day in Mato Grosso to 2.8 mm/day in Acre.

  4. Unexpected high decomposition of legume residues in dry season soils from tropical coffee plantations and crop lands

    OpenAIRE

    Abera, Girma; Wolde-Meskel, Endalkachew; Bakken, Lars

    2014-01-01

    International audience; Crop residues are essential fertilizer source of low-input farming systems in Sub-Saharan Africa. However, crop residues provide nutrients only if they decompose in the soil. Decomposition is assumed to be very low during the dry season due to the scarcity of water, but there are few quantitative knowledge on decomposition under such conditions. Therefore, we studied the decomposition of legume residues, haricot bean (Phaseolus vulgaris L.), and pigeon pea (Cajanus caj...

  5. White-faced monkey (Cebus capucinus) ecology and management in neotropical agricultural landscapes during the dry season

    OpenAIRE

    Williams, Heather E; Vaughan, Christopher

    2015-01-01

    Habitat use by a C. capucinus troop was studied in an agricultural landscape during late dry season (March-April 1994) in northwest Costa Rica. Riparian forests, palm canals and living fence rows accounted for 82 % of observations, significantly more than the other six habitats present. The study troop consumed 24 species of plants and five animals. Feeding concentrated on the introduced African oil palm (Elaeis guineensis) (33.6 %) and mango (Mangifera indica) (27.2 %), found mostly in palm ...

  6. White-faced monkey (Cebus capucinus) ecology and management in neotropical agricultural landscapes during the dry season

    OpenAIRE

    Williams, Heather E; Christopher Vaughan

    2001-01-01

    Habitat use by a C. capucinus troop was studied in an agricultural landscape during late dry season (March-April 1994) in northwest Costa Rica. Riparian forests, palm canals and living fence rows accounted for 82 % of observations, significantly more than the other six habitats present. The study troop consumed 24 species of plants and five animals. Feeding concentrated on the introduced African oil palm (Elaeis guineensis) (33.6 %) and mango (Mangifera indica) (27.2 %), found mostly in palm ...

  7. Organic matter addition in organic farming – Impact on root development and yields in maize and cowpea over dry seasons

    OpenAIRE

    Sangakkara, Dr Ravi; Bandaranayake, Mr P; Dissanayake, Ms U; Gajanayake, Ms J

    2008-01-01

    Organic matter and its proper management are vital in tropical organic farming to maintain productivity. A field study thus placed rice straw or Gliricidia leaves on the soil surface or the material was incorporated into soil. The impact of these treatments on soil moisture, root development and yields of organically grown maize or cowpea were evaluated in an Asian dry season. Incorporation increased soil moisture retention in the soil and hence induced better root growth, culminating in high...

  8. Coupled prediction of flood response and debris flow initiation during warm- and cold-season events in the Southern Appalachians, USA

    OpenAIRE

    Tao, J.; A. P. Barros

    2014-01-01

    Debris flows associated with rainstorms are a frequent and devastating hazard in the Southern Appalachians in the United States. Whereas warm-season events are clearly associated with heavy rainfall intensity, the same cannot be said for the cold-season events. Instead, there is a relationship between large (cumulative) rainfall events independently of season, and thus hydrometeorological regime, and debris flows. This suggests that the dynamics of subsurface hydrologic proc...

  9. Experimental and model analysis of evapotranspiration and percolation losses in present and future rainfall scenarios in seasonally dry tropics

    Science.gov (United States)

    Lima, J. D.; Gondim, P. S.; Silva, R. A.; Gomes, C. A.; Souza, E. S.; Vico, G.; Soares, W. A.; Feng, X.; Montenegro, S. M.; Antonino, A. C.; Porporato, A.

    2013-12-01

    Evapotranspiration losses with their link to the surface energy balance are a major determinant of the ecohydrological conditions of vegetation, especially in semi-arid ecosystems and crops. Grassland ecosystems account for approximately 32% of global natural vegetation, and cover 170 million ha in Brazil, with 2.5 million ha in the Pernambuco State of the semiarid-NE Brazil. The water balance (WB) and Bowen ratio - energy balance (EB) methods were used in conjunction to lysimeters and eddy covariance methods to come up with reliable estimates for water fluxes in the conditions of extreme seasonal and interannual variability of NE Brazil. The SiSPAT (Simple Soil-Plant-Atmosphere Transfer Model) model was also used to help quantify the seasonal and diurnal variations in energy and water vapour exchanges over grasslands. The ET estimates were obtained with WB and EB methods during the wet and dry season in a grassland in NE Brazil, using a rain gauge, a pyranometer, a net radiometer and sensors for measuring air temperature and relative humidity at two levels, as well as automated sensors for measuring soil water content at depths of 0.10, 0.20, 0.30 and 0.40 m. During the dry period, the low stored soil water limited the grass production and LAI, and as a consequence most of the net radiation (62%) was consumed in sensible heat flux (H) compared to during the wet period (52%). In both seasons, the water flow in the lower limit of soil (z = 0.30 m) occurred only in the downward direction, losing 23.68 mm by drainage in wet period and only 0.19 mm in dry period. The best results for evapotranspiration were obtained with the EB method and the SiSPAT model. These results were then used to estimate the hydrologic partitioning in future climatic conditions where seasonal and interannual rainfall variability is predicted to increase.

  10. Hydrological and geomorphological controls on a mangrove forest maintenance during the dry season in the Pacific Coast of Nicaragua

    Science.gov (United States)

    Calderon, Heyddy; Weeda, Ruben; Uhlenbrook, Stefan

    2014-05-01

    Hydrological and geomorphological processes are key to mangrove forest growth and development. However, very few studies have been carried out in Central American mangroves to understand their hydrological functioning. Here, a small mangrove forest (0.2 km2) in the South Pacific coast of Nicaragua was investigated to determine sources of freshwater inputs and fluxes of water and nutrients to the sea during the dry season. The general groundwater flow direction is from NE to SW towards the sea. The aquifer is composed of clay and alluvial deposits overlying a fractured shale unit. Shallow groundwater is influenced by a nearby town through infiltration of grey water and pit latrines. Groundwater from the mangrove showed Mn2+ and Fe2+ presence indicating occurrence of denitrification and the role of the mangrove as a nutrient sink. Also, refreshening and salinization processes were identified near the river, indicated by different water facies. Freshwater inputs from precipitation and groundwater discharge maintain adequate salt gradients. The water balance showed an increase of around 619 m3 d-1 in storage during a 22 study period during the dry season, which is reflected by increased hydraulic heads and river stage. Water storage is fostered by low conductivity soil materials and beach ridges parallel to the coast line, whereby the latter occassionally breach due to overtopping of surface water. These conditions favor forest subsistence during the dry season, allowing the mangrove to continue to provide ecological and economic benefits in terms of protection against flooding, habitat for numerous species and tourist attraction.

  11. Soil CO2 Efflux Dynamics in the Northern Pantanal of Mato Grosso, Brazil during the Wet-Dry Season Transition

    Science.gov (United States)

    Pinto-Jr, O. B.; Vourlitis, G. L.; Hentz, C. S.; Arruda, P. H. Z. D.; Santanna, F. B.; Dias, M. D. F.; de Musis, C. R.; Nogueira, J. D. S.

    2014-12-01

    The roles of tropical wetlands in the global carbon (C) cycle are still poorly understood, especially in seasonally flooded forests that are expected to be important sinks for atmospheric CO2. We measured soil CO2 efflux during the wet-dry transition period in a seasonally flooded palm-dominated forest (locally known as Acorizal) to determine the effect of litter input and seasonal hydrology. Measurements were performed monthly as part of a field litter manipulation experiment consisting of three treatments (litter removal, litter addition, and control; n = 6 plots per treatment), and our research objectives were to determine how soil CO2 efflux varied as a function of (1) litter input, (2) root density, and (3) seasonal variation in soil water content. We found that litter addition significantly increased soil CO2 efflux, but there was no relationship between root density and soil CO2 efflux. Efflux was highest during the wet season and declined as soil water content declined. Our data demonstrate that variations in litter inputs and soil water content are important controls on soil CO2 efflux in seasonally flooded tropical forests.

  12. Wet and dry atmospheric depositions of inorganic nitrogen during plant growing season in the coastal zone of Yellow River Delta.

    Science.gov (United States)

    Yu, Junbao; Ning, Kai; Li, Yunzhao; Du, Siyao; Han, Guangxuan; Xing, Qinghui; Wu, Huifeng; Wang, Guangmei; Gao, Yongjun

    2014-01-01

    The ecological problems caused by dry and wet deposition of atmospheric nitrogen have been widespread concern in the world. In this study, wet and dry atmospheric depositions were monitored in plant growing season in the coastal zone of the Yellow River Delta (YRD) using automatic sampling equipment. The results showed that SO4 (2-) and Na(+) were the predominant anion and cation, respectively, in both wet and dry atmospheric depositions. The total atmospheric nitrogen deposition was ~2264.24 mg m(-2), in which dry atmospheric nitrogen deposition was about 32.02%. The highest values of dry and wet atmospheric nitrogen deposition appeared in May and August, respectively. In the studied area, NO3 (-)-N was the main nitrogen form in dry deposition, while the predominant nitrogen in wet atmospheric deposition was NH4 (+)-N with ~56.51% of total wet atmospheric nitrogen deposition. The average monthly attribution rate of atmospheric deposition of NO3 (-)-N and NH4 (+)-N was ~31.38% and ~20.50% for the contents of NO3 (-)-N and NH4 (+)-N in 0-10 cm soil layer, respectively, suggested that the atmospheric nitrogen was one of main sources for soil nitrogen in coastal zone of the YRD.

  13. SEASONAL CHARACTERIZATION OF DUST DAYS,MASS CONCENTRATION AND DRY DEPOSITION OF ATMOSPHERIC AEROSOLS OVER QINGDAO, CHINA

    Institute of Scientific and Technical Information of China (English)

    Renjian Zhang; Mingxing Wang; Lifang Sheng; Yutaka Kanai; Atsuyuki Ohta

    2004-01-01

    The seasonal characterization of dust days, mass concentration and dry deposition of atmospheric aerosols were investigated using the historical data of dust days observed over Qingdao during the period from 1961 to 2001and ground-based aerosol sampling data collected in the period from May 2001 to November 2002. In Qingdao most of the dust days occurred in spring and in winter and no dust days existed in summer. The seasonal variation of the uplifting dust day over Qingdao was in phase with that analyzed over North China. The mean mass concentration of the total values and phase of the seasonal oscillation for fine particles were very similar to those for coarse particles except for the month March, during which the concentration of the coarse particles was about 4 times as high as that of the fine particles. Comparison between seasonal variation of mass concentration of aerosols and dust days indicated that high frequency of uplifting dust day was accompanied by high TSP mass concentration. The TSP mass concentration measured by the low-volume instrument was about 30% lower than that measured by high-volume instrument, though the two data sets are highly correlated (correlation coefficient=0.89). The dry deposition flux during the observation period from as that over Beijing.

  14. Nearing the cold-arid limits of microbial life in permafrost of an upper dry valley, Antarctica.

    Science.gov (United States)

    Goordial, Jacqueline; Davila, Alfonso; Lacelle, Denis; Pollard, Wayne; Marinova, Margarita M; Greer, Charles W; DiRuggiero, Jocelyn; McKay, Christopher P; Whyte, Lyle G

    2016-07-01

    Some of the coldest and driest permafrost soils on Earth are located in the high-elevation McMurdo Dry Valleys (MDVs) of Antarctica, but little is known about the permafrost microbial communities other than that microorganisms are present in these valleys. Here, we describe the microbiology and habitable conditions of highly unique dry and ice-cemented permafrost in University Valley, one of the coldest and driest regions in the MDVs (1700 m above sea level; mean temperature -23 °C; no degree days above freezing), where the ice in permafrost originates from vapour deposition rather than liquid water. We found that culturable and total microbial biomass in University Valley was extremely low, and microbial activity under ambient conditions was undetectable. Our results contrast with reports from the lower-elevation Dry Valleys and Arctic permafrost soils where active microbial populations are found, suggesting that the combination of severe cold, aridity, oligotrophy of University Valley permafrost soils severely limit microbial activity and survival.

  15. Beef cattle welfare evaluation during the dry season in the northern ...

    African Journals Online (AJOL)

    A cattle welfare index was estimated through 14 visual indicators in the cow-calf ... water availability; water distribution; water distance; water appearance; heat ... cold protection through management; cattle docility and cattle body condition.

  16. Effects of Savanna trees on soil nutrient limitation and carbon-sequestration potential in dry season

    Science.gov (United States)

    Becker, Joscha; Gütlein, Adrian; Sierra Cornejo, Natalia; Kiese, Ralf; Hertel, Dietrich; Kuzyakov, Yakov

    2016-04-01

    limitation and thus in C mineralization and sequestration. The effects on soil respiration are present, even under strong water scarcity. Therefore, the capability of a savanna ecosystem to act as a C sink during dry season is mainly (directly and indirectly) dependent on the spatial abundance of trees.

  17. Seasonal monitoring of deep-sea megabenthos in Barkley Canyon cold seep by internet operated vehicle (IOV).

    Science.gov (United States)

    Doya, Carolina; Chatzievangelou, Damianos; Bahamon, Nixon; Purser, Autun; De Leo, Fabio C; Juniper, S Kim; Thomsen, Laurenz; Aguzzi, Jacopo

    2017-01-01

    Knowledge of the processes shaping deep-sea benthic communities at seasonal scales in cold-seep environments is incomplete. Cold seeps within highly dynamic regions, such as submarine canyons, where variable current regimes may occur, are particularly understudied. Novel Internet Operated Vehicles (IOVs), such as tracked crawlers, provide new techniques for investigating these ecosystems over prolonged periods. In this study a benthic crawler connected to the NEPTUNE cabled infrastructure operated by Ocean Networks Canada was used to monitor community changes across 60 m2 of a cold-seep area of the Barkley Canyon, North East Pacific, at ~890 m depth within an Oxygen Minimum Zone (OMZ). Short video-transects were run at 4-h intervals during the first week of successive calendar months, over a 14 month period (February 14th 2013 to April 14th 2014). Within each recorded transect video megafauna abundances were computed and changes in environmental conditions concurrently measured. The responses of fauna to environmental conditions as a proxy of seasonality were assessed through analysis of abundances in a total of 438 video-transects (over 92 h of total footage). 7698 fauna individuals from 6 phyla (Cnidaria, Ctenophora, Arthropoda, Echinodermata, Mollusca, and Chordata) were logged and patterns in abundances of the 7 most abundant taxa (i.e. rockfish Sebastidae, sablefish Anoplopoma fimbria, hagfish Eptatretus stoutii, buccinids (Buccinoidea), undefined small crabs, ctenophores Bolinopsis infundibulum, and Scyphomedusa Poralia rufescens) were identified. Patterns in the reproductive behaviour of the grooved tanner crab (Chionnecetes tanneri) were also indicated. Temporal variations in biodiversity and abundance in megabenthic fauna was significantly influenced by variabilities in flow velocity flow direction (up or down canyon), dissolved oxygen concentration and month of study. Also reported here for the first time are transient mass aggregations of grooved tanner

  18. Preliminary results on seasonal changes in flower bud cold hardiness of sour cherry

    DEFF Research Database (Denmark)

    Liu, Guangping; Pagter, Majken; Andersen, Lillie

    2012-01-01

    Irregular yields of Prunus cerasus ‘Stevnsbaer Birgitte’, which is the preferred sour cherry cultivar in Denmark, have been proposed to be a result of freeze injury to floral tissues. This study determined floral mortality of P. cerasus ‘Stevnsbaer Birgitte’ and the supposedly more cold hardy P...

  19. Effect of ascorbic acid administration on erythrocyte osmotic fragility of pigs transported by road during the hot-dry season.

    Science.gov (United States)

    Asala, Olayinka O; Ayo, Joseph O; Rekwot, Peter I; Minka, Ndazo S; Omoniwa, David O; Adenkola, Adeshina Y

    2011-04-01

    The experiments were performed in order to determine the effect of 8-h road transportation of pigs on erythrocytes osmotic fragility during the hot-dry season, and the ameliorative role of ascorbic acid. Twenty-three adult pigs comprising of both sexes served as subjects for the study. Thirteen pigs administered ascorbic acid (AA) per os 30 min before transportation, at a dose rate of 100 mg/kg served as experimental animals, while ten pigs administered with distilled water per os served as control, and were transported for 8 h during the hot-dry season. EDTA blood samples collected a day before (pre-transportation), immediately after 8-h transportation and 7 days post-transportation were used to determine erythrocyte osmotic fragility. The ambient temperature (AT) and relative humidity (RH) measured within the vehicle ranged between 30.5-39.0 °C and 40.0-71.0% respectively. These values were outside the thermoneutral zone for the pig, indicating that the season was thermally stressful. Results obtained showed a significant difference (p<0.05) in percent haemolysis recorded at NaCl concentrations of 0.4% and 0.6% immediately after transportation in experimental pigs and at 0.5, 0.6, 0.8 and 0.9% NaCl concentrations in experimental pigs 7 days post-transportation. In conclusion, result from the present study indicated that 8-h road transportation during the hot-dry season could induce stress resulting in haemolysis of erythrocytes and AA administration ameliorated the stress.

  20. Dry spell, onset and cessation of the wet season rainfall in the Upper Baro-Akobo Basin, Ethiopia

    Science.gov (United States)

    Kebede, Asfaw; Diekkrüger, Bernd; Edossa, Desalegn C.

    2016-05-01

    In this study, maximum dry spell length and number of dry spell periods of rainy seasons in the upper Baro-Akobo River basin which is a part of the Nile basin, Western Ethiopia, were investigated to analyse the drought trend. Daily rainfall records of the period 1972-2000 from eight rain gauge stations were used in the analysis, and Mann-Kendall test was used to test trends for significance. Furthermore, the beginning and end of the trend development in the dry spell were also tested using the sequential version of Mann-Kendall test. Results have shown that there is neither clear monotonic trend found in dry spell for the basin nor significant fluctuation in the onset, cession and duration of rainfall in the Baro-Akobo river basin. This sufficiently explains why rain-fed agriculture has suffered little in the western part of Ethiopia. The predictable nature of dry spell pattern may have allowed farmers to adjust to rainfall variability in the basin. Unlike many parts of Ethiopia, the Baro-Akobo basin climate variability is not a limiting factor for rain-fed agriculture productivity which may contribute significantly to national food security.

  1. Dry spell, onset and cessation of the wet season rainfall in the Upper Baro-Akobo Basin, Ethiopia

    Science.gov (United States)

    Kebede, Asfaw; Diekkrüger, Bernd; Edossa, Desalegn C.

    2017-08-01

    In this study, maximum dry spell length and number of dry spell periods of rainy seasons in the upper Baro-Akobo River basin which is a part of the Nile basin, Western Ethiopia, were investigated to analyse the drought trend. Daily rainfall records of the period 1972-2000 from eight rain gauge stations were used in the analysis, and Mann-Kendall test was used to test trends for significance. Furthermore, the beginning and end of the trend development in the dry spell were also tested using the sequential version of Mann-Kendall test. Results have shown that there is neither clear monotonic trend found in dry spell for the basin nor significant fluctuation in the onset, cession and duration of rainfall in the Baro-Akobo river basin. This sufficiently explains why rain-fed agriculture has suffered little in the western part of Ethiopia. The predictable nature of dry spell pattern may have allowed farmers to adjust to rainfall variability in the basin. Unlike many parts of Ethiopia, the Baro-Akobo basin climate variability is not a limiting factor for rain-fed agriculture productivity which may contribute significantly to national food security.

  2. Wear Behaviour of Hard Cr Coatings for Cold Forming Tools Under Dry Sliding Conditions

    Directory of Open Access Journals (Sweden)

    S. Mitrović

    2012-03-01

    Full Text Available Cr hard coatings are largely used in industry in metal cutting and cold forming processes; This work on quantitative way represents improvement, in terms of wear resistance, which is obtained by depositing Cr hard coating on foundation material. Wear testing is done on tribometer with block –on –disc contact geometry at sliding contact of Cr hard coated sample with steel disc. Testing was performed in conditions without lubrication at variable value of contact parameters (normal load, sliding speed. Cr hard coatings in all contact conditions show smaller values of wear rate.

  3. Factors affecting the abundance of leaf-litter arthropods in unburned and thrice-burned seasonally-dry Amazonian forests.

    Directory of Open Access Journals (Sweden)

    Juliana M Silveira

    Full Text Available Fire is frequently used as a land management tool for cattle ranching and annual crops in the Amazon. However, these maintenance fires often escape into surrounding forests, with potentially severe impacts for forest biodiversity. We examined the effect of experimental fires on leaf-litter arthropod abundance in a seasonally-dry forest in the Brazilian Amazon. The study plots (50 ha each included a thrice-burned forest and an unburned control forest. Pitfall-trap samples were collected at 160 randomly selected points in both plots, with sampling stratified across four intra-annual replicates across the dry and wet seasons, corresponding to 6, 8, 10 and 12 months after the most recent fire. Arthropods were identified to the level of order (separating Formicidae. In order to better understand the processes that determine arthropod abundance in thrice-burned forests, we measured canopy openness, understory density and litter depth. All arthropod taxa were significantly affected by fire and season. In addition, the interactions between burn treatment and season were highly significant for all taxa but Isoptera. The burned plot was characterized by a more open canopy, lower understory density and shallower litter depth. Hierarchical partitioning revealed that canopy openness was the most important factor explaining arthropod order abundances in the thrice-burned plot, whereas all three environmental variables were significant in the unburned control plot. These results reveal the marked impact of recurrent wildfires and seasonality on litter arthropods in this transitional forest, and demonstrate the overwhelming importance of canopy-openness in driving post-fire arthropod abundance.

  4. Morphogenesis of dwarf elephant grass clones in response to intensity and frequency of defoliation in dry and rainy seasons

    Directory of Open Access Journals (Sweden)

    Carlos Augusto de Miranda Gomide

    2011-07-01

    Full Text Available The aim of this study was to evaluate during the dry and rainy seasons the morphogenesis traits of two clones of dwarf elephant grass under different management strategies. The study was conducted in a factorial 2 × 2 × 3 design, using two clones, one green and one purple, two residual heights, 25 and 45 cm, and three frequencies of defoliation according to the light interception of 90, 95 and 100%. The design was a randomized block with three replications. The variables were leaf elongation and leaf senescence rate, stem elongation rate and phyllochron. The leaf lifespan and the number of living leaves per tiller were also estimated. The clones presented low stem elongation rates, showing adaptation for grazing use. In the rainy season, the light interception of 100% promoted the highest stem elongation rate and increased the leaf senescence rate. In the dry season, the leaf elongation rate (LER was higher for the purple clone than for the green one (23 vs 15 mm.tiller-1.day-1. In the rainy season, the LER of the green clone exceeded that of the purple one by 71% (149 vs. 87 mm.tiller-1.day-1. The phyllochron varied among clones only in the rainy season, when the value was 4.6 days.leaf-1 for the green clone and 8.4 days.leaf-1 for the purple one; both of these values are below the mean value observed during the drought (21,6 days.leaf-1. The residual heights did not affect, in an isolated way, any of the variables. The clones are well adapted to grazing, presenting low stem elongation rates. The interval between defoliations should consider the scope of light interception between 90 and 95%. The green clone, with a greater flow of biomass, requires handling with shorter defoliation intervals.

  5. Tradeoffs between global warming and day length on the start of the carbon uptake period in seasonally cold ecosystems.

    Science.gov (United States)

    Wohlfahrt, Georg; Cremonese, Edoardo; Hammerle, Albin; Hörtnagl, Lukas; Galvagno, Marta; Gianelle, Damiano; Marcolla, Barbara; di Cella, Umberto Morra

    2013-12-16

    It is well established that warming leads to longer growing seasons in seasonally cold ecosystems. Whether this goes along with an increase in the net ecosystem carbon dioxide (CO2) uptake is much more controversial. We studied the effects of warming on the start of the carbon uptake period (CUP) of three mountain grasslands situated along an elevational gradient in the Alps. To this end we used a simple empirical model of the net ecosystem CO2 exchange, calibrated and forced with multi-year empirical data from each site. We show that reductions in the quantity and duration of daylight associated with earlier snowmelts were responsible for diminishing returns, in terms of carbon gain, from longer growing seasons caused by reductions in daytime photosynthetic uptake and increases in nighttime losses of CO2. This effect was less pronounced at high, compared to low, elevations, where the start of the CUP occurred closer to the summer solstice when changes in day length and incident radiation are minimal.

  6. Projected changes of rainfall seasonality and dry spells in a high concentration pathway 21st century scenario

    CERN Document Server

    Pascale, Salvatore; Feng, Xue; Porporato, Amilcare; Hasson, Shabeh ul

    2014-01-01

    In this diagnostic study we analyze changes of rainfall seasonality and dry spells by the end of the twenty-first century under the most extreme IPCC5 emission scenario (RCP8.5) as projected by twenty-four coupled climate models participating to Coupled Model Intercomparison Project 5. We use estimates of the centroid of the monthly rainfall distribution as an index of the rainfall timing and a threshold-independent, information theory-based quantity such as relative entropy (RE) to quantify the concentration of annual rainfall and the number of dry months and to build a monsoon dimensionless seasonality index (DSI). The RE is projected to increase, with high inter-model agreement over Mediterranean-type regions (southern Europe, northern Africa and southern Australia) and areas of South and Central America, implying an increase in the number of dry days up to one month by the end of the twenty-first century. Positive RE changes are also projected over the monsoon regions of southern Africa and North America,...

  7. Cold season soil respiration in response to grazing and warming in the High Arctic Svalbard

    DEFF Research Database (Denmark)

    Strebel, Ditte; Elberling, Bo; Morgner, Elke;

    2010-01-01

    ) and solid-state 13C nuclear magnetic resonance (NMR) spectroscopy. Results reveal variations in soil carbon cycling, with significant seasonal trends controlled by temperature, water content and snow. Experimental warming (OTCs) increased near-surface temperatures in the growing season, resulting......The influence of goose grazing intensity and open-topped chambers (OTCs) on near-surface quantities and qualities of soil organic carbon (SOC) was evaluated in wet and mesic ecosystems in Svalbard. This study followed up a field experiment carried out in 2003-05 (part of the project Fragility...

  8. Residential Solar-Based Seasonal Thermal Storage Systems in Cold Climates: Building Envelope and Thermal Storage

    OpenAIRE

    Alexandre Hugo; Radu Zmeureanu

    2012-01-01

    The reduction of electricity use for heating and domestic hot water in cold climates can be achieved by: (1) reducing the heating loads through the improvement of the thermal performance of house envelopes, and (2) using solar energy through a residential solar-based thermal storage system. First, this paper presents the life cycle energy and cost analysis of a typical one-storey detached house, located in Montreal, Canada. Simulation of annual energy use is performed using the TRNSYS softwar...

  9. Cold Spray Coating of Submicronic Ceramic Particles on Poly(vinyl alcohol) in Dry and Hydrogel States

    Science.gov (United States)

    Moreau, David; Borit, François; Corté, Laurent; Guipont, Vincent

    2017-06-01

    We report an approach using cold spray technology to coat poly(vinyl alcohol) (PVA) in polymer and hydrogel states with hydroxyapatite (HA). Using porous aggregated HA powder, we hypothesized that fragmentation of the powder upon cold spray could lead to formation of a ceramic coating on the surface of the PVA substrate. However, direct spraying of this powder led to complete destruction of the swollen PVA hydrogel substrate. As an alternative, HA coatings were successfully produced by spraying onto dry PVA substrates prior to swelling in water. Dense homogeneous HA coatings composed of submicron particles were obtained using rather low-energy spraying parameters (temperature 200-250 °C, pressure 1-3 MPa). Coated PVA substrates could swell in water without removal of the ceramic layer to form HA-coated hydrogels. Microscopic observations and in situ measurements were used to explain how local heating and impact of sprayed aggregates induced surface roughening and strong binding of HA particles to the molten PVA substrate. Such an approach could lead to design of ceramic coatings whose roughness and crystallinity can be finely adjusted to improve interfacing with biological tissues.

  10. Unusual past dry and wet rainy seasons over Southern Africa and South America from a climate perspective

    Directory of Open Access Journals (Sweden)

    Omar Bellprat

    2015-09-01

    Full Text Available Southern Africa and Southern South America have experienced recent extremes in dry and wet rainy seasons which have caused severe socio-economic damages. Selected past extreme events are here studied, to estimate how human activity has changed the risk of the occurrence of such events, by applying an event attribution approach (Stott et al., 2004comprising global climate models of Coupled Model Intercomparison Project 5 (CMIP5. Our assessment shows that models' representation of mean precipitation variability over Southern South America is not adequate to make a robust attribution statement about seasonal rainfall extremes in this region. Over Southern Africa, we show that unusually dry austral summers as occurred during 2002/2003 have become more likely, whereas unusually wet austral summers like that of 1999/2000 have become less likely due to anthropogenic climate change. There is some tentative evidence that the risk of extreme high 5-day precipitation totals (as observed in 1999/2000 have increased in the region. These results are consistent with CMIP5 models projecting a general drying trend over SAF during December–January–February (DJF but also an increase in atmospheric moisture availability to feed heavy rainfall events when they do occur. Bootstrapping the confidence intervals of the fraction of attributable risk has demonstrated estimates of attributable risk are very uncertain, if the events are very rare. The study highlights some of the challenges in making an event attribution study for precipitation using seasonal precipitation and extreme 5-day precipitation totals and considering natural drivers such as ENSO in coupled ocean–atmosphere models.

  11. Mapping Clearances in Tropical Dry Forests Using Breakpoints, Trend, and Seasonal Components from MODIS Time Series: Does Forest Type Matter?

    Directory of Open Access Journals (Sweden)

    Kenneth Grogan

    2016-08-01

    Full Text Available Tropical environments present a unique challenge for optical time series analysis, primarily owing to fragmented data availability, persistent cloud cover and atmospheric aerosols. Additionally, little is known of whether the performance of time series change detection is affected by diverse forest types found in tropical dry regions. In this paper, we develop a methodology for mapping forest clearing in Southeast Asia using a study region characterised by heterogeneous forest types. Moderate Resolution Imaging Spectroradiometer (MODIS time series are decomposed using Breaks For Additive Season and Trend (BFAST and breakpoints, trend, and seasonal components are combined in a binomial probability model to distinguish between cleared and stable forest. We found that the addition of seasonality and trend information improves the change model performance compared to using breakpoints alone. We also demonstrate the value of considering forest type in disturbance mapping in comparison to the more common approach that combines all forest types into a single generalised forest class. By taking a generalised forest approach, there is less control over the error distribution in each forest type. Dry-deciduous and evergreen forests are especially sensitive to error imbalances using a generalised forest model i.e., clearances were underestimated in evergreen forest, and overestimated in dry-deciduous forest. This suggests that forest type needs to be considered in time series change mapping, especially in heterogeneous forest regions. Our approach builds towards improving large-area monitoring of forest-diverse regions such as Southeast Asia. The findings of this study should also be transferable across optical sensors and are therefore relevant for the future availability of dense time series for the tropics at higher spatial resolutions.

  12. 冷季型草坪的建植与管理技术%Investigation on Planting and Management of Cold Season Lawn

    Institute of Scientific and Technical Information of China (English)

    胡慧芳; 李刚

    2013-01-01

      冷季型草坪是北方园林绿化的重要组成部分,针对北方季节特点以及冷季型草生长发育对环境条件要求,从11个方面探讨了其建植和管理技术。%Cold season lawn is widely used in landscaping fields in the northern region .According to northern climate and their requirements on the environment conditions ,planting and management of cold season lawn were investigated from 11 aspects .

  13. Land use and land use change effects on nitrous oxide emissions in the seasonally dry ecosystems of Zimbabwe

    DEFF Research Database (Denmark)

    Nyamadzawo, G; Chirinda, Ngoni; Mapanda, F

    2012-01-01

    Nitrous oxide (N2O) is a greenhouse gas (GHG) with a considerable warming potential and involvement in the destruction of stratospheric ozone. The conversion of savannas to agricultural land has the potential of changing the characteristics and gas exchange of the ecosystems dramatically....... The savanna woodlands cover over 95% of Zimbabwe’s forest area, and are divided into five woodland types: Acacia, miombo, mopane, teak (Baikiaea Plurijuga) and Terminalia-Combretaceae. This review is aimed at exploring the effects of land-use changes and land management practices on N2O emissions in Zimbabwe...... emissions were mainly concentrated in the wet season as N2O production is strongly enhanced by high soil moisture. During the dry season pyrogenic emissions were also important sources of N2O, contributing, an estimated 6.7 Gg N2O annually. Land use change in the form of biomass burning and conversion...

  14. Evidence of hydraulic lift for pre-rainy season leaf out and dry-season stem water enrichment in Sclerocarya birrea, a tropical agroforestry tree

    Science.gov (United States)

    Ceperley, Natalie; Mande, Theophile; Rinaldo, Andrea; Parlange, Marc B.

    2014-05-01

    We use stable isotopes of water as tracers to follow water use by five Sclerocarya birrea trees in a catchment in South Eastern Burkina Faso interspersed with millet fields, gallery forest, Sudanian savanna, and fallow fields. Isotopic ratios were determined from water extracted from stems of the trees and sub-canopy soil of two of them, while nearby ground water, precipitation, and surface water was sampled weekly. A unique configuration of sensors connected with a wireless sensor network of meteorological stations measured sub-canopy shading, the temperature and humidity in the canopy, through-fall, and soil moisture under two of the trees. Both water extracted from sap and water extracted from soil is extremely enriched in the dry season, but drop to levels close to the ground water in February or March, which coincides with the growth of leaves. Dates of leaf out were confirmed by changes in δDH and δO18 concentrations of water, photographic documentation & pixel analysis, and analysis of sub-canopy radiation and proceeded the rise in humidity and flow that was later detected in the sub-canopy soil, the trunk of the tree (sap-flow), and atmosphere (canopy VPD). Examination of the isotopic signature suggests that size of tree plays an important role in duration and timing of this leaf-out as well as the degree of enrichment during the peak of the dry season. Further examination of the isotopic signatures of the roots suggested that the trees are performing hydraulic redistribution, or lifting the ground water and "sharing it" with the soil in the rooting zone in the dry season. The enriched level of xylem in this case is a product of water loss, and enrichment, along the travel path of the water from the roots to the tip of the stem, as evidenced by the variation according to size of tree. Vapor pressure deficit, soil water, and soil moisture interactions support this picture of interacting controls, separate from hydrologic triggers on the water movement in

  15. Documentary realism and film pleasure: Two moments from Euzhan Palcy’s A Dry White Season

    OpenAIRE

    Higgins, J

    1992-01-01

    This essay examines some of the strains and tensions around the notions of film pleasure and documentary realism in the film A Dry White Season. It offers a schematic analysis of the history of the idea of a politics of film pleasure in the early work on mass culture of the Frankfurt School and F.R. Leavis, and more recent debates in feminism. This general account then provides the context for the examination of some of the problems in Palcy's film, focusing particularly on the question of Pa...

  16. Variations in soil carbon sequestration and their determinants along a precipitation gradient in seasonally dry tropical forest ecosystems.

    Science.gov (United States)

    Campo, Julio; Merino, Agustín

    2016-05-01

    The effect of precipitation regime on the C cycle of tropical forests is poorly understood, despite the existence of models that suggest a drier climate may substantially alter the source-sink function of these ecosystems. Along a precipitation regime gradient containing 12 mature seasonally dry tropical forests growing under otherwise similar conditions (similar annual temperature, rainfall seasonality, and geological substrate), we analyzed the influence of variation in annual precipitation (1240 to 642 mm) and duration of seasonal drought on soil C. We investigated litterfall, decomposition in the forest floor, and C storage in the mineral soil, and analyzed the dependence of these processes and pools on precipitation. Litterfall decreased slightly - about 10% - from stands with 1240 mm yr(-1) to those with 642 mm yr(-1), while the decomposition decreased by 56%. Reduced precipitation strongly affected C storage and basal respiration in the mineral soil. Higher soil C storage at the drier sites was also related to the higher chemical recalcitrance of litter (fine roots and forest floor) and the presence of charcoal across sites, suggesting an important indirect influence of climate on C sequestration. Basal respiration was controlled by the amount of recalcitrant organic matter in the mineral soil. We conclude that in these forest ecosystems, the long-term consequences of decreased precipitation would be an increase in organic layer and mineral soil C storage, mainly due to lower decomposition and higher chemical recalcitrance of organic matter, resulting from changes in litter composition and, likely also, wildfire patterns. This could turn these seasonally dry tropical forests into significant soil C sinks under the predicted longer drought periods if primary productivity is maintained.

  17. Performance of the Enhanced Vegetation Index to Detect Inner-annual Dry Season and Drought Impacts on Amazon Forest Canopies

    Science.gov (United States)

    Brede, B.; Verbesselt, J.; Dutrieux, L.; Herold, M.

    2015-04-01

    The Amazon rainforests represent the largest connected forested area in the tropics and play an integral role in the global carbon cycle. In the last years the discussion about their phenology and response to drought has intensified. A recent study argued that seasonality in greenness expressed as Enhanced Vegetation Index (EVI) is an artifact of variations in sun-sensor geometry throughout the year. We aimed to reproduce these results with the Moderate-Resolution Imaging Spectroradiometer (MODIS) MCD43 product suite, which allows modeling the Bidirectional Reflectance Distribution Function (BRDF) and keeping sun-sensor geometry constant. The derived BRDF-adjusted EVI was spatially aggregated over large areas of central Amazon forests. The resulting time series of EVI spanning the 2000-2013 period contained distinct seasonal patterns with peak values at the onset of the dry season, but also followed the same pattern of sun geometry expressed as Solar Zenith Angle (SZA). Additionally, we assessed EVI's sensitivity to precipitation anomalies. For that we compared BRDF-adjusted EVI dry season anomalies to two drought indices (Maximum Cumulative Water Deficit, Standardized Precipitation Index). This analysis covered the whole of Amazonia and data from the years 2000 to 2013. The results showed no meaningful connection between EVI anomalies and drought. This is in contrast to other studies that investigate the drought impact on EVI and forest photosynthetic capacity. The results from both sub-analyses question the predictive power of EVI for large scale assessments of forest ecosystem functioning in Amazonia. Based on the presented results, we recommend a careful evaluation of the EVI for applications in tropical forests, including rigorous validation supported by ground plots.

  18. Increased dry-season length over southern Amazonia in recent decades and its implication for future climate projection.

    Science.gov (United States)

    Fu, Rong; Yin, Lei; Li, Wenhong; Arias, Paola A; Dickinson, Robert E; Huang, Lei; Chakraborty, Sudip; Fernandes, Katia; Liebmann, Brant; Fisher, Rosie; Myneni, Ranga B

    2013-11-05

    We have observed that the dry-season length (DSL) has increased over southern Amazonia since 1979, primarily owing to a delay of its ending dates (dry-season end, DSE), and is accompanied by a prolonged fire season. A poleward shift of the subtropical jet over South America and an increase of local convective inhibition energy in austral winter (June-August) seem to cause the delay of the DSE in austral spring (September-November). These changes cannot be simply linked to the variability of the tropical Pacific and Atlantic Oceans. Although they show some resemblance to the effects of anthropogenic forcings reported in the literature, we cannot attribute them to this cause because of inadequate representation of these processes in the global climate models that were presented in the Intergovernmental Panel on Climate Change's Fifth Assessment Report. These models significantly underestimate the variability of the DSE and DSL and their controlling processes. Such biases imply that the future change of the DSE and DSL may be underestimated by the climate projections provided by the Intergovernmental Panel on Climate Change's Fifth Assessment Report models. Although it is not clear whether the observed increase of the DSL will continue in the future, were it to continue at half the rate of that observed, the long DSL and fire season that contributed to the 2005 drought would become the new norm by the late 21st century. The large uncertainty shown in this study highlights the need for a focused effort to better understand and simulate these changes over southern Amazonia.

  19. Estimation and comparison of benefits due to feeding hay and silage during the dry season on commercial dual-purpose cattle production systems in Honduras and Costa Rica

    NARCIS (Netherlands)

    Schoonhoven, A.D.; Holmann, F.; Argel, P.; Ordoñez, J.C.; Chaves, J.

    2006-01-01

    Smallholders with dual-purpose cattle production systems in most Central America experience a shortage of forages during the dry season (4-8 month. As a result, substantially lower milk production and weight gain occurs. Dual-purpose operations seeking to maximize milk and beef production in the dry

  20. Estimation of the time of death of decomposed or skeletonized bodies found outdoors in cold season in Sapporo city, located in the northern district of Japan.

    Science.gov (United States)

    Matoba, Kotaro; Terazawa, Koichi

    2008-03-01

    In Sapporo city, located in the northern district of Japan, it is very difficult to estimate the time of death of decomposed or skeletonized bodies found outdoors in cold season (November-April) because postmortem changes are markedly retarded in the season compared with warm season (May-October), and the bodies are often damaged and skeletonized by carnivorous animals such as wild dogs and foxes. However, they cannot damage the brain in the cranium. The brain is mainly damaged by fly larvae. In Sapporo city, we can estimate that the time of death of a cadaver found outdoors in the cold season is in the beginning of November or before if fly larvae hatched in autumn exist on the cadaver, and that the time of death is in the beginning of November or after if fly larvae hatched in autumn do not exist and most of the brain remains in the cranium.

  1. Cooling and changing seasonality in the Southern Alps, New Zealand during the Antarctic Cold Reversal

    OpenAIRE

    Vandergoes, M.J.; A. C. Dieffenbacher-Krall; Newnham, R.M.; Denton, G.H.; Blaauw, Maarten

    2008-01-01

    A comprehensively 14C AMS dated pollen and chironomid record from Boundary Stream Tarn provides the first chironomid-derived temperature reconstruction to quantify temperature change during Lateglacial times (17,500–10,000 cal yr BP) in the Southern Alps, New Zealand. The records indicate a ca 1000-year disruption to the Lateglacial warming trend and an overall cooling consistent with the Antarctic Cold Reversal (ACR). The main interval of chironomid-inferred summer temperature depression (2–...

  2. Analysis of the effects of wet and dry seasons on a Mediterranean river basin: consequences for coastal waters and its quality management

    OpenAIRE

    Sebastiá Frasquet, María Teresa; Rodilla Alamá, Miguel; Falco Giaccaglia, Silvia Laura; Sanchís Blay, José Andrés

    2013-01-01

    Rivers play a major role in the delivery of nutrients to coastal ecosystems which are essential for ecosystem productivity. However, the increase of nutrients due to anthropogenic activities can cause eutrophication problems. This study analyzes the seasonal variation of phytoplankton communities in the coastal receiving waters of a Mediterranean river. Two scenarios are compared: the wet and the dry season with distinctive characteristics. During the wet season agricultural runoff and combin...

  3. Effects of redecoration of a hospital isolation room with natural materials on stress levels of denizens in cold season

    Science.gov (United States)

    Ohta, Hiromi; Maruyama, Megumi; Tanabe, Yoko; Hara, Toshiko; Nishino, Yoshihiko; Tsujino, Yoshio; Morita, Eishin; Kobayashi, Shotai; Shido, Osamu

    2008-05-01

    We investigated the effects of redecoration of a hospital isolation room with natural materials on thermoregulatory, cardiovascular and hormonal parameters of healthy subjects staying in the room. Two isolation rooms with almost bilaterally-symmetrical arrangements were used. One room (RD) was redecorated with wood paneling and Japanese paper, while the other (CN) was unchanged (with concrete walls). Seven healthy male subjects stayed in each room for over 24 h in the cold season. Their rectal temperature (Tre) and heart rate, and the room temperature (Ta) and relative humidity were continuously measured. Arterial blood pressures, arterial vascular compliance, thermal sensation and thermal comfort were measured every 4 h except during sleeping. Blood was sampled after the stay in the rooms. In RD, Ta was significantly higher by about 0.4°C and relative humidity was lower by about 5% than in CN. Diurnal Tre levels of subjects in RD significantly differed from those in CN, i.e., Tres were significantly higher in RD than in CN especially in the evening. In RD, the subjects felt more thermally-comfortable than in CN. Redecoration had minimal effects on cardiovascular parameters. Plasma levels of catecholamines and antidiuretic hormone did not differ, while plasma cortisol level was significantly lower after staying in RD than in CN by nearly 20%. The results indicate that, in the cold season, redecoration with natural materials improves the thermal environment of the room and contributes to maintaining core temperature of denizens at preferable levels. It also seems that redecoration of room could attenuate stress levels of isolated subjects.

  4. Microstructure, microhardness and dry friction behavior of cold-sprayed tin bronze coatings

    Science.gov (United States)

    Guo, Xueping; Zhang, Ga; Li, Wen-Ya; Dembinski, Lucas; Gao, Yang; Liao, Hanlin; Coddet, Christian

    2007-12-01

    In this paper, two types of tin bronze coatings (Cu-6 wt.% Sn and Cu-8 wt.% Sn) were prepared by cold spray process. The as-sprayed coatings were subjected to a vacuum heat treatment at 600 °C for 3 h. The coating microstructure, microhardness and tribological performance were characterized. The effects of the tin content and the vacuum heat treatment on the microstructure, microhardness and tribological behavior of the coatings were investigated. It is found that the as-sprayed CuSn6 (As6) and CuSn8 (As8) coatings exhibit practically an identical porosity. Meanwhile, As8 presents a higher microhardness than As6. In addition, the increase of the tin content in the powder feedstock leads to a lower wear rate. After a heat treatment, coating porosities are significantly reduced. However, the coating hardness is significantly decreased and the coating presents a much decreased wear resistance. For the as-sprayed coatings, such factors as ploughing and particle delamination could determine the sliding process. The heat treatment results in a distinct modification of the tribological behavior. For the annealed coatings, the adhesion, between the coating and the counterpart, could play a dominant role in the sliding process.

  5. Cold adaptive traits revealed by comparative genomic analysis of the eurypsychrophile Rhodococcus sp. JG3 isolated from high elevation McMurdo Dry Valley permafrost, Antarctica.

    Science.gov (United States)

    Goordial, Jacqueline; Raymond-Bouchard, Isabelle; Zolotarov, Yevgen; de Bethencourt, Luis; Ronholm, Jennifer; Shapiro, Nicole; Woyke, Tanja; Stromvik, Martina; Greer, Charles W; Bakermans, Corien; Whyte, Lyle

    2016-02-01

    The permafrost soils of the high elevation McMurdo Dry Valleys are the most cold, desiccating and oligotrophic on Earth. Rhodococcus sp. JG3 is one of very few bacterial isolates from Antarctic Dry Valley permafrost, and displays subzero growth down to -5°C. To understand how Rhodococcus sp. JG3 is able to survive extreme permafrost conditions and be metabolically active at subzero temperatures, we sequenced its genome and compared it to the genomes of 14 mesophilic rhodococci. Rhodococcus sp. JG3 possessed a higher copy number of genes for general stress response, UV protection and protection from cold shock, osmotic stress and oxidative stress. We characterized genome wide molecular adaptations to cold, and identified genes that had amino acid compositions favourable for increased flexibility and functionality at low temperatures. Rhodococcus sp. JG3 possesses multiple complimentary strategies which may enable its survival in some of the harshest permafrost on Earth.

  6. Ozone production and transport over the Amazon Basin during the dry-to-wet and wet-to-dry transition seasons

    Directory of Open Access Journals (Sweden)

    M. M. Bela

    2014-06-01

    Full Text Available The Regional Carbon Balance in Amazonia (BARCA campaign provided the first Amazon Basin-wide aircraft measurements of O3 during both the dry-to-wet (November and December 2008 and wet-to-dry (May 2009 transition seasons. Extremely low background values (3 levels (40–60 ppb were seen during the dry-to-wet transition to the east and south of Manaus, where biomass burning emissions of O3 precursors were present. Chemistry simulations with the CCATT-BRAMS and WRF-Chem models are within the error bars of the observed O3 profiles in the boundary layer (0–3 km a.s.l. in polluted conditions. However, the models overestimate O3 in the boundary layer in clean conditions, despite lacking the predominant NO source from soil. In addition, O3 simulated by the models was either within the error bars or lower than BARCA observations in mid-levels (3–5 km a.s.l., indicating that the models do not represent the free troposphere – boundary layer gradient in O3. Total tropospheric O3 retrieved from OMI/MLS was higher than that simulated by the models, suggesting that the satellite observations are dominated by the middle troposphere and long-range processes and are not a~good indication of O3 conditions in the PBL. Additional simulations with WRF-Chem showed that the model O3 production is very sensitive to both the O3 deposition velocities, which were about one half of observed values, and the NOx emissions. These results have implications for the monitoring and prediction of increases in O3 production in the Amazon Basin as the regional population grows.

  7. Water depletion: An improved metric for incorporating seasonal and dry-year water scarcity into water risk assessments

    Directory of Open Access Journals (Sweden)

    Kate A. Brauman

    2016-01-01

    Full Text Available Abstract We present an improved water-scarcity metric we call water depletion, calculated as the fraction of renewable water consumptively used for human activities. We employ new data from the WaterGAP3 integrated global water resources model to illustrate water depletion for 15,091 watersheds worldwide, constituting 90% of total land area. Our analysis illustrates that moderate water depletion at an annual time scale is better characterized as high depletion at a monthly time scale and we are thus able to integrate seasonal and dry-year depletion into the water depletion metric, providing a more accurate depiction of water shortage that could affect irrigated agriculture, urban water supply, and freshwater ecosystems. Applying the metric, we find that the 2% of watersheds that are more than 75% depleted on an average annual basis are home to 15% of global irrigated area and 4% of large cities. An additional 30% of watersheds are depleted by more than 75% seasonally or in dry years. In total, 71% of world irrigated area and 47% of large cities are characterized as experiencing at least periodic water shortage.

  8. Stress tolerance and ecophysiological ability of an invader and a native species in a seasonally dry tropical forest.

    Science.gov (United States)

    Oliveira, Marciel Teixeira; Matzek, Virginia; Dias Medeiros, Camila; Rivas, Rebeca; Falcão, Hiram Marinho; Santos, Mauro Guida

    2014-01-01

    Ecophysiological traits of Prosopis juliflora (Sw.) DC. and a phylogenetically and ecologically similar native species, Anadenanthera colubrina (Vell.) Brenan, were studied to understand the invasive species' success in caatinga, a seasonally dry tropical forest ecosystem of the Brazilian Northeast. To determine if the invader exhibited a superior resource-capture or a resource-conservative strategy, we measured biophysical and biochemical parameters in both species during dry and wet months over the course of two years. The results show that P. juliflora benefits from a flexible strategy in which it frequently outperforms the native species in resource capture traits under favorable conditions (e.g., photosynthesis), while also showing better stress tolerance (e.g., antioxidant activity) and water-use efficiency in unfavorable conditions. In addition, across both seasons the invasive has the advantage over the native with higher chlorophyll/carotenoids and chlorophyll a/b ratios, percent N, and leaf protein. We conclude that Prosopis juliflora utilizes light, water and nutrients more efficiently than Anadenanthera colubrina, and suffers lower intensity oxidative stress in environments with reduced water availability and high light radiation.

  9. Effect of different levels of honey on physiological, growth and carcass traits of broiler chickens during dry season

    Directory of Open Access Journals (Sweden)

    Oyegunle Emmanuel OKE

    2016-12-01

    Full Text Available The objective of this trial was to investigate the effect of different levels of honey in drinking water on the responses of broiler chickens during dry season in hot humid tropics. Three hundred Oba Marshall broiler chicks were used for this study. The day-old chicks were randomly assigned to five treatment groups with each treatment having four replicates of 15 birds. The first 4 treatment groups were daily supplied drinking water without honey (0H, with 20 ml (20H, 40 ml (40H and 60 ml (60H of honey per liter of water. The fifth group received drinking water supplemented with 500 mg vitamin C per liter of water (C. Records on daily weight gain (WG and feed intake (FI were taken. Feed conversion ratio (FCR was calculated as the ratio of gain to feed consumed. The supplementation of honey in the drinking water for broiler chickens in 60H during hot dry season in the hot humid tropics improved some stress indices, body weight gain and relative spleen weight.

  10. Multi-season climate synchronized historical fires in dry forests (1650-1900), Northern Rockies, USA

    Science.gov (United States)

    Emily K. Heyerdahl; Penelope Morgan; James P. Riser

    2008-01-01

    Our objective was to infer the climate drivers of regionally synchronous fire years in dry forests of the U.S. northern Rockies in Idaho and western Montana. During our analysis period (1650-­1900), we reconstructed fires from 9245 fire scars on 576 trees (mostly ponderosa pine, Pinus ponderosa P. & C. Lawson) at 21 sites and compared them to...

  11. Development of cold and drought tolerant short-season maize germplasm for fuel and feed utilization

    Directory of Open Access Journals (Sweden)

    Marcelo J Carena

    2013-04-01

    Full Text Available Maize has become a profitable alternative for North Dakota (ND farmers and ranchers. However, U.S. northern industry hybrids still lack cold and drought stress tolerance as well as adequate grain quality for ethanol and feedstock products. Moreover, there is a need to increase the value of feedstock operations before and after ethanol utilization. The ND maize breeding program initiated the development of hybrids with high quality protein content through the Early Quality Protein Maize for Feedstock (EarlyQPMF project. The North Dakota State University (NDSU maize breeding program acts as a genetic provider to foundation seed companies, retailer seed companies, processing industry, and breeders nationally and internationally. In the past 10 years, NDSU was awarded 9 PVP maize certificates and released 38 maize products. Within those, 13 inbred lines were exclusively released to a foundation seed company for commercial purposes. In addition, 2 hybrids were identified for commercial production in central and western ND.

  12. Using bacterial and necrophagous insect dynamics for post-mortem interval estimation during cold season: Novel case study in Romania.

    Science.gov (United States)

    Iancu, Lavinia; Carter, David O; Junkins, Emily N; Purcarea, Cristina

    2015-09-01

    Considering the biogeographical characteristics of forensic entomology, and the recent development of forensic microbiology as a complementary approach for post-mortem interval estimation, the current study focused on characterizing the succession of necrophagous insect species and bacterial communities inhabiting the rectum and mouth cavities of swine (Sus scrofa domesticus) carcasses during a cold season outdoor experiment in an urban natural environment of Bucharest, Romania. We monitored the decomposition process of three swine carcasses during a 7 month period (November 2012-May 2013) corresponding to winter and spring periods of a temperate climate region. The carcasses, protected by wire cages, were placed on the ground in a park type environment, while the meteorological parameters were constantly recorded. The succession of necrophagous Diptera and Coleoptera taxa was monitored weekly, both the adult and larval stages, and the species were identified both by morphological and genetic characterization. The structure of bacterial communities from swine rectum and mouth tissues was characterized during the same time intervals by denaturing gradient gel electrophoresis (DGGE) and sequencing of 16S rRNA gene fragments. We observed a shift in the structure of both insect and bacterial communities, primarily due to seasonal effects and the depletion of the carcass. A total of 14 Diptera and 6 Coleoptera species were recorded on the swine carcasses, from which Calliphora vomitoria and C. vicina (Diptera: Calliphoridae), Necrobia violacea (Coleoptera: Cleridae) and Thanatophilus rugosus (Coleoptera: Silphidae) were observed as predominant species. The first colonizing wave, primarily Calliphoridae, was observed after 15 weeks when the temperature increased to 13°C. This was followed by Muscidae, Fanniidae, Anthomyiidae, Sepsidae and Piophilidae. Families belonging to Coleoptera Order were observed at week 18 when temperatures raised above 18°C, starting with

  13. The Frustrating Lives of Climate Scientists - 45 Years of Warm, Cold, Wet and Dry

    Science.gov (United States)

    Toon, O. B.; Hartwick, V.; Urata, R. A.

    2016-12-01

    Mariner 9 arrived at Mars in November 1971, where it revealed giant volcanoes and dry river valleys some of which originated from rainfall or runoff. Some geologists think there were oceans, tidal waves, craters that filled to their rims and then overflowed or didn't overflow, and river deltas reaching into the ancient seas and lakes. Climate scientists have stumbled through a 45 year-long chain of failed explanations for these geologic data. CO2 in greater abundance than now is likely involved, but not sufficient. Adding CH4 , CO2 clouds, or SO2 have faltered on further study. Three ideas are still being kicked around, two of which are able to make Mars warm, but may have geologic issues. First, is the idea of adding H2 to the CO2, which warms sufficiently in climate models. However, the large quantities needed are a challenge to outgassing models. Second, is impacts, the largest of which would mobilize most of the water in the regolith. Geologists object that the water from impacts would not last long enough to carve rivers. However, no one has explored the concurrent generation of the regolith by these impacts, which would create a loose, easily erodible surface. Are the rivers all in ancient regolith? If some rivers are in bedrock it would be harder to explain by impacts. Finally, impacts may triggered water/cloud greenhouses. Such a climate state would be long lasting, requires only a modest background atmosphere of carbon dioxide, and would fade away when the carbon dioxide dropped below a few hundred mbar. However, not all climate models have been able to produce such water driven greenhouse warming. In this talk I will outline the history of these climate models, point to evidence that might discriminate between them, describe how the water greenhouse models work or don't work, and suggest some new projects that might be done to decide just how warm and wet Mars may have been.

  14. Assessment of seasonal soil moisture forecasts over Southern South America with emphasis on dry and wet events

    Science.gov (United States)

    Spennemann, Pablo; Rivera, Juan Antonio; Osman, Marisol; Saulo, Celeste; Penalba, Olga

    2017-04-01

    The importance of forecasting extreme wet and dry conditions from weeks to months in advance relies on the need to prevent considerable socio-economic losses, mainly in regions of large populations and where agriculture is a key value for the economies, like Southern South America (SSA). Therefore, to improve the understanding of the performance and uncertainties of seasonal soil moisture and precipitation forecasts over SSA, this study aims to: 1) perform a general assessment of the Climate Forecast System version-2 (CFSv2) soil moisture and precipitation forecasts; and 2) evaluate the CFSv2 ability to represent an extreme drought event merging observations with forecasted Standardized Precipitation Index (SPI) and the Standardized Soil Moisture Anomalies (SSMA) based on GLDAS-2.0 simulations. Results show that both SPI and SSMA forecast skill are regionally and seasonally dependent. In general a fast degradation of the forecasts skill is observed as the lead time increases with no significant metrics for forecast lead times longer than 2 months. Based on the assessment of the 2008-2009 extreme drought event it is evident that the CFSv2 forecasts have limitations regarding the identification of drought onset, duration, severity and demise, considering both meteorological (SPI) and agricultural (SSMA) drought conditions. These results have some implications upon the use of seasonal forecasts to assist agricultural practices in SSA, given that forecast skill is still too low to be useful for lead times longer than 2 months.

  15. Improving the nutritive value of wheat straw with urea and yeast culture for dry season feeding of dairy cows.

    Science.gov (United States)

    Kashongwe, Olivier Basole; Migwi, Preminius; Bebe, Bockline Omedo; Ooro, Patrick Auwor; Onyango, Tobias Atali; Osoo, John Odhiambo

    2014-08-01

    The study evaluated the effects of feeding urea treated/supplemented wheat straw-based diets with addition of yeast culture (YC) as a dry season feed for dairy cows. Wheat straw diets with 3.6% urea and 5.8% molasses were formulated to upgrade nonprotein nitrogen levels and fibre degradation in the rumen. Yeast culture was included at 0 and 10 g/cow/day in mixer with commercial dairy meal to improve on fibre degradation and milk yield. Two experiments were conducted. Firstly, an in sacco dry matter degradability (DMD) trial with three steers in a completely randomized design (CRD) with a 3 × 2 factorial arrangement to determine the effects on intake and rumen degradation parameters. Secondly, feeding trial with 18 lactating cows in a 3 × 2 factorial arrangement at two levels of yeast culture (0 and 10 g/cow/day) and three types of urea interventions: No intervention (WS); addition of urea to straw at the time of feeding (USWS); and 7 days incubation of straw with urea (UTWS). Yeast cultures addition had no effect on rumen pH and NH3-N, but urea intervention showed an effect on rumen pH with USWS being lowest (p urea interventions and yeast culture addition had no effect (p > 0.05) on dry matter intake, milk yield, and milk composition but they increased (p < 0.05) propionate yields.

  16. Residential Solar-Based Seasonal Thermal Storage Systems in Cold Climates: Building Envelope and Thermal Storage

    Directory of Open Access Journals (Sweden)

    Alexandre Hugo

    2012-10-01

    Full Text Available The reduction of electricity use for heating and domestic hot water in cold climates can be achieved by: (1 reducing the heating loads through the improvement of the thermal performance of house envelopes, and (2 using solar energy through a residential solar-based thermal storage system. First, this paper presents the life cycle energy and cost analysis of a typical one-storey detached house, located in Montreal, Canada. Simulation of annual energy use is performed using the TRNSYS software. Second, several design alternatives with improved thermal resistance for walls, ceiling and windows, increased overall air tightness, and increased window-to-wall ratio of South facing windows are evaluated with respect to the life cycle energy use, life cycle emissions and life cycle cost. The solution that minimizes the energy demand is chosen as a reference house for the study of long-term thermal storage. Third, the computer simulation of a solar heating system with solar thermal collectors and long-term thermal storage capacity is presented. Finally, the life cycle cost and life cycle energy use of the solar combisystem are estimated for flat-plate solar collectors and evacuated tube solar collectors, respectively, for the economic and climatic conditions of this study.

  17. Agricultural water use, crop water footprints and irrigation strategies in the seasonally dry Guanacaste region in Costa Rica

    Science.gov (United States)

    Morillas, Laura; Johnson, Mark S.; Hund, Silja V.; Steyn, Douw G.

    2017-04-01

    Agriculture is the main productive sector and a major water-consuming sector in the seasonally-dry Guanacaste region of north-western Costa Rica. Agriculture in the region is intensifying at the same time that seasonal water scarcity is increasing. The climate of this region is characterized by a prolonged dry season from December to March, followed by a bimodal wet season from April to November. The wet season has historically experienced periodic oscillations in rainfall timing and amounts resulting from variations of several large-scale climatic features (El Niño Southern Oscillation, the Pacific Decadal Oscillation, the Atlantic Multidecadal Oscillation and the North Atlantic Oscillation). However, global circulation models now project more recurrent variations in total annual rainfall, changes in rainfall temporal distribution, and increased temperatures in this region. This may result in a lengthening of the dry season and an increase in water scarcity and water-related conflicts as water resources are already limited and disputed in this area. In fact, this region has just undergone a four-year drought over the 2012-2015 period, which has intensified water related conflicts and put agricultural production at risk. In turn, the recent drought has also increased awareness of the local communities regarding the regional threat of water scarcity and the need of a regional water planning. The overall goal of this research is to generate data to characterize water use by the agricultural sector in this region and asses its sustainability in the regional context. Towards this goal, eddy-covariance flux towers were deployed on two extensive farms growing regionally-representative crops (melon/rice rotation and sugarcane) to evaluate, monitor and quantify water use in large-scale farms. The two identically instrumented stations provide continuous measurements of evapotranspiration and CO2 fluxes, and are equipped with additional instrumentation to monitor

  18. Three Gorges Dam alters the Changjiang (Yangtze) river water cycle in the dry seasons: Evidence from H-O isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Deng, Kai [School of Ocean and Earth Science, Tongji University, Shanghai, 200092 (China); State Key Laboratory of Marine Geology, Tongji University, Shanghai 200092 (China); Yang, Shouye, E-mail: syyang@tongji.edu.cn [State Key Laboratory of Marine Geology, Tongji University, Shanghai 200092 (China); Laboratory for Marine Geology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266061 (China); Lian, Ergang [School of Ocean and Earth Science, Tongji University, Shanghai, 200092 (China); State Key Laboratory of Marine Geology, Tongji University, Shanghai 200092 (China); Li, Chao [State Key Laboratory of Marine Geology, Tongji University, Shanghai 200092 (China); Yang, Chengfan; Wei, Hailun [School of Ocean and Earth Science, Tongji University, Shanghai, 200092 (China); State Key Laboratory of Marine Geology, Tongji University, Shanghai 200092 (China)

    2016-08-15

    As the largest hydropower project in the world, the Three Gorges Dam (TGD) has attracted great concerns in terms of its impact on the Changjiang (Yangtze) River and coastal marine environments. In this study, we measured or collected the H-O isotopic data of river water, groundwater and precipitation in the mid-lower Changjiang catchment during the dry seasons of recent years. The aim was to investigate the changes of river water cycle in response to the impoundment of the TGD. Isotopic evidences suggested that the mid-lower Changjiang river water was ultimately derived from precipitation, but dominated by the mixing of different water masses with variable sources and isotopic signals as well. The isotopic parameter “deuterium excess” (d-excess) yielded large fluctuations along the mid-lower mainstream during the initial stage of the TGD impoundment, which was inherited from the upstream water with inhomogeneous isotopic signals. However, as the reservoir water level rising to the present stage, small variability of d-excess was observed along the mid-lower mainstream. This discrepancy could be explained that the TGD impoundment had significantly altered the water cycle downstream the dam, with the rising water level increasing the residence time and enhancing the mixing of reservoir water derived from upstream. This eventually resulted in the homogenization of reservoir water, and thus small fluctuations of d-excess downstream the dam after the quasi-normal stage (2008 to present). We infer that the retention effect of large reservoirs has greatly buffered the d-excess natural variability of water cycle in large river systems. Nevertheless, more research attention has to be paid to the damming effect on the water cycle in the river, estuarine and coastal areas, especially during the dry seasons. - Highlights: • Stable H-O isotopes indicate the Changjiang river water cycle in dry seasons. • The isotopic parameter “d-excess” reveals the origins of

  19. Seasonal shifting of surplus renewable energy in a power system located in a cold region

    Directory of Open Access Journals (Sweden)

    Jorge Morel

    2014-10-01

    Full Text Available The Fukushima nuclear disaster in 2011 changed Japan's strategy for reducing CO2 emissions. The government is now placing more emphasis on the development of nonCO2-emitting distributed generation systems such as wind, solar, and tidal power to reduce greenhouse gas emissions and guarantee electricity supply in the case of a natural disaster. This paper proposes a strategy for the exploitation of wind, solar, and tidal resources in a cold region in Japan by utilizing surplus energy from the summer and spring during winter. It also aims to determine the most favorable energy mix of these renewable sources and storage system types. The study is performed by calculating hourly demand and renewable energy supply for the city in one year, which is based on actual data of demand, solar irradiation, wind speeds, and tidal current speeds. The costs of the components of the renewable power plants and storage systems are considered, and different proportions of generation outputs are evaluated with different types of storage systems. According to results, the configuration containing the hydrogen storage system using organic chemical hydride methylcyclohexane (OCHM is the most economical but is still more expensive than one using a conventional generation system. Moreover, we confirm that the cost of CO2 emissions is the key element for leveling the playing field between conventional and renewable generation from an economic perspective. The cost of CO2 emissions to public health as well as those costs related to the interruption of services during a catastrophe must be carefully calculated with other issues from conventional power projects to perform a precise comparative evaluation between both types of generation systems.

  20. Caatinga Revisited: Ecology and Conservation of an Important Seasonal Dry Forest

    Science.gov (United States)

    de Albuquerque, Ulysses Paulino; de Lima Araújo, Elcida; El-Deir, Ana Carla Asfora; de Lima, André Luiz Alves; Souto, Antonio; Bezerra, Bruna Martins; Ferraz, Elba Maria Nogueira; Maria Xavier Freire, Eliza; Sampaio, Everardo Valadares de Sá Barreto; Las-Casas, Flor Maria Guedes; de Moura, Geraldo Jorge Barbosa; Pereira, Glauco Alves; de Melo, Joabe Gomes; Alves Ramos, Marcelo; Rodal, Maria Jesus Nogueira; Schiel, Nicola; de Lyra-Neves, Rachel Maria; Alves, Rômulo Romeu Nóbrega; de Azevedo-Júnior, Severino Mendes; Telino Júnior, Wallace Rodrigues; Severi, William

    2012-01-01

    Besides its extreme climate conditions, the Caatinga (a type of tropical seasonal forest) hosts an impressive faunal and floristic biodiversity. In the last 50 years there has been a considerable increase in the number of studies in the area. Here we aimed to present a review of these studies, focusing on four main fields: vertebrate ecology, plant ecology, human ecology, and ethnobiology. Furthermore, we identify directions for future research. We hope that the present paper will help defining actions and strategies for the conservation of the biological diversity of the Caatinga. PMID:22919296

  1. Caatinga revisited: ecology and conservation of an important seasonal dry forest.

    Science.gov (United States)

    de Albuquerque, Ulysses Paulino; de Lima Araújo, Elcida; El-Deir, Ana Carla Asfora; de Lima, André Luiz Alves; Souto, Antonio; Bezerra, Bruna Martins; Ferraz, Elba Maria Nogueira; Maria Xavier Freire, Eliza; Sampaio, Everardo Valadares de Sá Barreto; Las-Casas, Flor Maria Guedes; de Moura, Geraldo Jorge Barbosa; Pereira, Glauco Alves; de Melo, Joabe Gomes; Alves Ramos, Marcelo; Rodal, Maria Jesus Nogueira; Schiel, Nicola; de Lyra-Neves, Rachel Maria; Alves, Rômulo Romeu Nóbrega; de Azevedo-Júnior, Severino Mendes; Telino Júnior, Wallace Rodrigues; Severi, William

    2012-01-01

    Besides its extreme climate conditions, the Caatinga (a type of tropical seasonal forest) hosts an impressive faunal and floristic biodiversity. In the last 50 years there has been a considerable increase in the number of studies in the area. Here we aimed to present a review of these studies, focusing on four main fields: vertebrate ecology, plant ecology, human ecology, and ethnobiology. Furthermore, we identify directions for future research. We hope that the present paper will help defining actions and strategies for the conservation of the biological diversity of the Caatinga.

  2. Caatinga Revisited: Ecology and Conservation of an Important Seasonal Dry Forest

    Directory of Open Access Journals (Sweden)

    Ulysses Paulino de Albuquerque

    2012-01-01

    Full Text Available Besides its extreme climate conditions, the Caatinga (a type of tropical seasonal forest hosts an impressive faunal and floristic biodiversity. In the last 50 years there has been a considerable increase in the number of studies in the area. Here we aimed to present a review of these studies, focusing on four main fields: vertebrate ecology, plant ecology, human ecology, and ethnobiology. Furthermore, we identify directions for future research. We hope that the present paper will help defining actions and strategies for the conservation of the biological diversity of the Caatinga.

  3. Effects of Land Use Change and Seasonality of Precipitation on Soil Nitrogen in a Dry Tropical Forest Area in the Western Llanos of Venezuela

    Science.gov (United States)

    González-Pedraza, Ana Francisca; Dezzeo, Nelda

    2014-01-01

    We evaluated changes of different soil nitrogen forms (total N, available ammonium and nitrate, total N in microbial biomass, and soil N mineralization) after conversion of semideciduous dry tropical forest in 5- and 18-year-old pastures (YP and OP, resp.) in the western Llanos of Venezuela. This evaluation was made at early rainy season, at end rainy season, and during dry season. With few exceptions, no significant differences were detected in the total N in the three study sites. Compared to forest soils, YP showed ammonium losses from 4.2 to 62.9% and nitrate losses from 20.0 to 77.8%, depending on the season of the year. In OP, the ammonium content increased from 50.0 to 69.0% at the end of the rainy season and decreased during the dry season between 25.0 and 55.5%, whereas the nitrate content increased significantly at early rainy season. The net mineralization and the potentially mineralizable N were significantly higher (P < 0.05) in OP than in forest and YP, which would indicate a better quality of the substrate in OP for mineralization. The mineralization rate constant was higher in YP than in forest and OP. This could be associated with a reduced capacity of these soils to preserve the available nitrogen. PMID:25610907

  4. Molecular composition of dicarboxylic acids, ketocarboxylic acids, α-dicarbonyls and fatty acids in atmospheric aerosols from Tanzania, East Africa during wet and dry seasons

    Directory of Open Access Journals (Sweden)

    S. L. Mkoma

    2013-02-01

    Full Text Available Atmospheric aerosol samples of PM2.5 and PM10 were collected during the wet and dry seasons in 2011 from a rural site in Tanzania and analysed for water-soluble dicarboxylic acids, ketocarboxylic acids, α-dicarbonyls, and fatty acids using a gas chromatography/flame ionization detector (GC/FID and GC/mass spectrometry. Here we report the molecular composition and sources of diacids and related compounds for wet and dry seasons. Oxalic acid (C2 was found as the most abundant diacid species followed by succinic and/or malonic acids whereas glyoxylic acid and glyoxal were the dominant ketoacid and α-dicarbonyl, respectively in both seasons in PM2.5 and PM10. Mean concentration of C2 in PM2.5 (121 ± 47 ng m−3 was lower in wet season than dry season (258 ± 69 ng m−3. Similarly, PM10 samples showed lower concentration of C2 (169 ± 42 ng m−3 in wet season than dry season (292 ± 165 ng m−3. Relative abundances of C2 in total diacids were 65% and 67% in PM2.5 and 65% and 64% in PM10 in the wet and dry seasons, respectively. Total concentrations of diacids (289–362 ng m−3, ketoacids (37.8–53.7 ng m−3, and α-dicarbonyls (5.7–7.8 ng m−3 in Tanzania are higher than those reported at a rural background site in Nylsvley (South Africa but comparable or lower than those reported from sites in Asia and Europe. Diacids and ketoacids were found to be present mainly in PM2.5 in both seasons (total α-dicarbonyls in the dry season, suggesting a production of organic acids from pyrogenic sources and photochemical oxidations. Averaged contributions of total diacids to aerosol total carbon were 1.4% in PM2.5 and 2.1% in PM10 during wet season and 3.3% in PM2.5 and 3.9% in PM10 during

  5. The chemical composition and bacteria communities in acid and metalliferous drainage from the wet-dry tropics are dependent on season.

    Science.gov (United States)

    Streten-Joyce, Claire; Manning, Judy; Gibb, Karen S; Neilan, Brett A; Parry, David L

    2013-01-15

    Acid and metalliferous drainage (AMD) occurs when sulphidic minerals, such as arsenopyrite, chalcopyrite and pyrite, are exposed to oxygen and water. Climate, geology and mine site practices can have a significant impact on AMD composition. The elemental composition of the AMD can also affect the bacterial community. Our hypothesis was that in the dry season the AMD at two mine sites, Rum Jungle and Mt Todd, in the Northern Territory, Australia, has a higher concentration of dissolved metals because standing water evaporates during the extended dry period. Our second hypothesis was that the wet and dry season bacteria community in AMD at Rum Jungle and Mt Todd are different, and this difference is correlated to seasonally specific changes in physicochemistry. The first hypothesis was tested by measuring elemental concentrations in AMD during the wet and dry seasons at Mt Todd and Rum Jungle mine sites. The physicochemical properties such as temperature, pH and dissolved oxygen were also measured. To test the second hypothesis, we extracted DNA from AMD samples collected at Rum Jungle and Mt Todd during the wet and dry seasons. The hypervariable V6 region of the bacterial 16S rRNA gene was sequenced by 454 pyrosequencing. The bacterial community composition was examined and related to physiochemical variables. The elemental concentrations in Rum Jungle AMD were higher in the dry season compared to the wet season, but at Mt Todd the elemental composition of AMD changed with year, rather than season. The bacteria community in AMD at Rum Jungle changed between the wet and dry season while in Mt Todd AMD the bacteria community from year 1 was significantly different from year 2. The data showed that the elemental composition and bacteria communities of AMD at Rum Jungle and Mt Todd are influenced by season, mine site practices and geological characteristics of the ore body. In addition, the iron oxidising bacteria Leptospirillum and Acidithiobacillus typically

  6. Nematodes parasites of the gray fox (Urocyon cinereoargenteus Schreber, 1775) in the seasonally dry tropical highlands of central Mexico.

    Science.gov (United States)

    Hernández-Camacho, Norma; Pineda-López, Raul; López-González, Carlos A; Jones, Robert W

    2011-06-01

    The gray fox (Urocyon cinereoargenteus Schreber, 1775) is the most abundant and opportunistic wild canid in Mexico. However, the parasites of this canid in Mexico are poorly known, and an intensive parasite survey is lacking. A survey of gray fox parasitological feces was conducted in El Cimatario National Park, a protected area representative of the seasonally dry, tropical highlands of Mexico. Feces were collected in six 1-km-length transects during the summer of 2003 and spring of 2004. The coproparasitoscopical survey registered nine species of nematodes, typical of wild and domestic canids such as Strongyloides stercoralis, Uncinaria stenocephala, Toxocara canis, Toxascaris leonina, Dioctophyme renale, Trichuris vulpis, Trichuris sp., and Capillaria sp. Ecological factors such as temperature and humidity appear to play a more important role in the establishment of these species of parasites in this protected area than the presence of domestic dogs.

  7. Water quality assessment of Lebanese coastal rivers during dry season and pollution load into the Mediterranean Sea.

    Science.gov (United States)

    Houri, Ahmad; El Jeblawi, Saadieh W

    2007-12-01

    The chemical and microbiological properties of Lebanese perennial coastal rivers were studied during the dry season extending from July to September 2004. The results indicate significant levels of pollution in all eight rivers. Although many physical and chemical variables were within WHO guidelines for drinking water, coliform levels were unacceptably high indicating pollution from untreated sewage. The most polluted rivers in most categories were the Abu Ali and Antelias. With the exception of bacterial and phosphate loadings, Awali River provides the highest amount of pollution to the Mediterranean mainly due to its high water flow, although it is one of the least polluted rivers. The urgent need for controlling wastewater dumping into river streams is emphasized. The data obtained should serve as a reference point to assess the efficiency of planned wastewater treatment plants.

  8. Growth, Mineral Deposition, and Physiological Responses of Broiler Chickens Offered Honey in Drinking Water during Hot-Dry Season

    Directory of Open Access Journals (Sweden)

    Monsuru Oladimeji Abioja

    2012-01-01

    Full Text Available Growing broilers were offered either 0 (0H, 10 (10H, 20 mL (20H honey, or 0.5 g vitamin C/litre water (AA during hot-dry season. Honey had no significant (>0.05 effect on feed intake (FI, weight gain (WG, feed conversion ratio (FCR, water intake (WI, survival (SURV, dressed percentage (DRE, breast meat (BRE, gizzard (GIZ, drumstick (DRU, shank (SHA, thigh (THI, tibia volume (VOL, and magnesium (MAG. Effect of honey was significant (0.005. Higher dose of honey lowered PR and HR. Honey significantly (0.05 affected. 20H broilers had higher THY than 0H and 10H groups. In conclusion, honey did not affect growth but might improve broilers’ welfare when offered up to 20H during hot periods.

  9. Influence of Water Temperature and Salinity on PH During Dry Season in Lower Dong Nai River System, Vietnam

    Directory of Open Access Journals (Sweden)

    Dung Dang Quoc

    2015-12-01

    Full Text Available This paper uses the gvSIG 2.2.0 software, IDW interpolation method, river and stream network data, and 36 sampling sites to build the maps of three monitored parameters such as pH, water temperature, and salinity in the Lower Dong Nai River system (2009-2010 in dry season. Based on an analysis of these maps and statistical assessment by using the R software, the correlations between pH, temperature, and salinity are clarified. The results show that the pH and temperature values have a tendency to decrease, whereas the salinity tends to increase annually. The pH value has good and significant correlations with the water temperature and salinity in both simple and multiple linear regression models. The results aim to provide a scientific reference for further research on the water environment in this area.

  10. Temporal relationships between colds, upper respiratory viruses detected by polymerase chain reaction, and otitis media in young children followed through a typical cold season.

    Science.gov (United States)

    Winther, Birgit; Alper, Cuneyt M; Mandel, Ellen M; Doyle, William J; Hendley, J Owen

    2007-06-01

    Otitis media is a frequent complication of a viral upper respiratory tract infection, and the reported co-incidence of those diseases increases with assay sensitivity and sampling density. We determined the incidence of otitis-media complications in young children when referenced to cold-like illnesses and to concurrent virus recovery from the nasopharynx. A total of 60 children from 24 families were followed from October 2003 through April 30, 2004, by daily parental recording of illness signs, weekly pneumatic otoscopic examinations, and periodic polymerase chain reaction assay of collected nasal fluids for common viruses. One hundred ninety-nine cold-like illnesses were observed, but a sample for virus assay was not collected concurrent with 71 episodes. Of the remainder, 73% of cold-like illnesses were temporally related to recovery of 1 or a combination of the assayed viruses, with rhinovirus predominating. For non-cold-like illness periods, 54 (18%) of 297 assays were positive for virus, and the virus frequency distribution was similar to that for cold-like illnesses. There were 93 diagnosed otitis-media episodes; 65 (70%) of these occurred during a cold-like illness. For the 79 otitis-media episodes with available nasal samples, 61 (77%) were associated with a positive virus result. In this population, the otitis-media complication rate for a cold-like illness was 33%. A cold-like illness was not a prerequisite for polymerase chain reaction detection of viruses in the nose and nasopharynx of young children. Viral detection by polymerase chain reaction in the absence of a cold-like illness is associated with complications in some subjects. Otitis media is a complication of viral infection both with and without concurrent cold-like illnesses, thus downwardly biasing coincidence estimates that use cold-based illnesses as the denominator.

  11. Substitution of soybean meal for cottonseed meal in multiple supplements for grazing beef heifers in the dry season

    Directory of Open Access Journals (Sweden)

    Román Maza Ortega

    2016-02-01

    Full Text Available The objective of this study was to evaluate the effect of substituting soybean meal for cottonseed meal in multiple supplements on the nutritional characteristics and performance of beef heifers in their postweaning phase on Brachiaria decumbens pastures during the dry season. Twenty-four Nellore beef heifers (average initial age and weight of 8 mo and 210±6 kg, respectively were used. The design was completely randomized, with four treatments and six replicates. Supplements contained approximately 30% crude protein (CP and a progressive substitution of soybean meal for cottonseed meal (0, 50 and 100%. The control animals received only a mineral mixture ad libitum, and those on the other treatments received supplementation at 1.0 kg/animal/day. No differences were found in ADG between supplemented and control animals (P>0.10. Supplementation increased crude protein (CP intake only (P<0.10. The level of substitution of soybean meal for cottonseed meal did not affect (P>0.10 the intake of supplemented animals. Supplementation elevated the apparent digestibility coefficients (P<0.10 of OM, CP, NFC and TDN, but not EE or NDFap (P>0.10. A positive linear effect (P<0.10 of the level of substitution of soybean meal for cottonseed cake was observed on the digestibility of OM, NFC and TDN. Supplementation and the level of substitution had an effect (P<0.10 on the serum urea nitrogen and urine urea nitrogen contents. Supplementation or substitution level had no effect on the flow of microbial nitrogen to the intestine (MICN or efficiency of microbial protein synthesis (EMPS (P>0.10. Substitution caused a decreasing linear effect (P<0.10 on microbial nitrogen/nitrogen intake ratio (MICNR. In conclusion, substitution of soybean meal for cottonseed meal in multiple supplements during the dry season does not impair the productive performance of beef heifers.

  12. Three Gorges Dam alters the Changjiang (Yangtze) river water cycle in the dry seasons: Evidence from H-O isotopes.

    Science.gov (United States)

    Deng, Kai; Yang, Shouye; Lian, Ergang; Li, Chao; Yang, Chengfan; Wei, Hailun

    2016-08-15

    As the largest hydropower project in the world, the Three Gorges Dam (TGD) has attracted great concerns in terms of its impact on the Changjiang (Yangtze) River and coastal marine environments. In this study, we measured or collected the H-O isotopic data of river water, groundwater and precipitation in the mid-lower Changjiang catchment during the dry seasons of recent years. The aim was to investigate the changes of river water cycle in response to the impoundment of the TGD. Isotopic evidences suggested that the mid-lower Changjiang river water was ultimately derived from precipitation, but dominated by the mixing of different water masses with variable sources and isotopic signals as well. The isotopic parameter "deuterium excess" (d-excess) yielded large fluctuations along the mid-lower mainstream during the initial stage of the TGD impoundment, which was inherited from the upstream water with inhomogeneous isotopic signals. However, as the reservoir water level rising to the present stage, small variability of d-excess was observed along the mid-lower mainstream. This discrepancy could be explained that the TGD impoundment had significantly altered the water cycle downstream the dam, with the rising water level increasing the residence time and enhancing the mixing of reservoir water derived from upstream. This eventually resulted in the homogenization of reservoir water, and thus small fluctuations of d-excess downstream the dam after the quasi-normal stage (2008 to present). We infer that the retention effect of large reservoirs has greatly buffered the d-excess natural variability of water cycle in large river systems. Nevertheless, more research attention has to be paid to the damming effect on the water cycle in the river, estuarine and coastal areas, especially during the dry seasons.

  13. Antioxidant content in two CAM bromeliad species as a response to seasonal light changes in a tropical dry deciduous forest.

    Science.gov (United States)

    González-Salvatierra, Claudia; Luis Andrade, José; Escalante-Erosa, Fabiola; García-Sosa, Karlina; Manuel Peña-Rodríguez, Luis

    2010-07-01

    Plants have evolved photoprotective mechanisms to limit photodamage; one of these mechanisms involves the biosynthesis of antioxidant metabolites to neutralize reactive oxygen species generated when plants are exposed to excess light. However, it is known that exposure of plants to conditions of extreme water stress and high light intensity results in their enhanced susceptibility to over-excitation of photosystem II and to photooxidative stress. In this investigation we used the 2,2-diphenyl-1-picrylhydrazyl reduction assay to conduct a broad survey of the effect of water availability and light exposure conditions on the antioxidant activity of the leaf extracts of two bromeliad species showing crassulacean acid metabolism. One of these was an epiphyte, Tillandsia brachycaulos, and the other a terrestrial species, Bromelia karatas. Both species were found growing wild in the tropical dry deciduous forest of Dzibilchaltún National Park, México. The microenvironment of T. brachycaulos and B. karatas experiences significant diurnal and seasonal light variations as well as changes in temperature and water availability. The results obtained showed that, for both bromeliads, increases in antioxidant activity occurred during the dry season, as a consequence of water stress and higher light conditions. Additionally, in T. brachycaulos there was a clear correlation between high light intensity conditions and the content of anthocyanins which accumulated below the leaf epidermis. This result suggests that the role of these pigments is as photoprotective screens in the leaves. The red coloration below the leaf epidermis of B. karatas was not due to anthocyanins but to other unidentified pigments.

  14. Warm and dry weather accelerates and elongates Cladosporium spore seasons in Poland.

    Science.gov (United States)

    Kasprzyk, Idalia; Kaszewski, Boguslaw Michal; Weryszko-Chmielewska, Elzbieta; Nowak, Malgorzata; Sulborska, Aneta; Kaczmarek, Joanna; Szymanska, Agata; Haratym, Weronika; Jedryczka, Malgorzata

    Temperature is the environmental factor that systematically changes for decades and, as in plants and animals, can significantly affect the growth and development of fungi, including the abundance of their sporulation. During the time of study (2010-2012), a rapid increase in air temperature was observed in Poland, which coincided with the substantial decrease in rainfall. The increase in annual mean temperatures at three monitoring sites of this study was 0.9 °C in Lublin and Rzeszow (east Poland) and 2.0 °C in Poznan (west Poland). Such warming of air masses was comparable to the average global air temperature rise in the period of 1880-2012 accounting for 0.85 °C, as reported by the Intergovernmental Panel on Climate Change. Moreover, there was a substantial decrease in rainfall, ranging from 32.7 % (Poznan) to 43.0 % (Rzeszow). We have demonstrated that under such conditions the mean and median values of total Cladosporium spore counts significantly increased and the spore seasons were greatly accelerated. Moreover, earlier start and later end of the season caused its extension, lasting from over 20 days in Rzeszow to around 60 days in Lublin and Poznan, when the cumulative amount of 5-95 % of spores was considered. The time of reaching the cumulative amount of 50 % of spores was up to 25 days earlier (difference in Poznan between 2010 and 2012). There was also a striking acceleration of the date of the maximal Cladosporium spore concentration per cubic metre of air (26 days for Lublin, 43 for Poznan and 56 for Rzeszow).

  15. Variation in soil water uptake and its effect on plant water status in Juglans regia L. during dry and wet seasons.

    Science.gov (United States)

    Sun, Shou-Jia; Meng, Ping; Zhang, Jin-Song; Wan, Xianchong

    2011-12-01

    Temporal and spatial variations in the water status of walnut trees (Juglans regia L.) and the soil in which they were growing were traced by analyzing the differences in hydrogen isotopes during spring and summer in a 7-year-old walnut stand. Walnut root dynamics were measured in both dry and wet seasons. Walnut roots were mainly distributed in the upper soil (0-30 cm depth), with around 60% of the total root mass in upper soil layers and 40% in deep soil layers (30-80 cm depth). The upper soil layers contributed 68% of the total tree water requirement in the wet season, but only 47% in the dry season. In the wet season, total roots, living roots and new roots were all significantly more abundant than in the dry season. There were significant differences in pre-dawn branch percentage loss of hydraulic conductance (PLC), pre-dawn leaf water potential and transpiration between the dry and wet seasons. Water content in the upper soil layers remarkably influenced xylem water stable-hydrogen isotope (δD) values. Furthermore, there were linear relationships between the xylem water δD value and pre-dawn branch PLC, pre-dawn leaf water potential, transpiration rate and photosynthetic rate. In summary, J. regia was compelled to take a larger amount of water from the deep soil layers in the dry season, but this shift could not prevent water stress in the plant. The xylem water δD values could be used as an indicator to investigate the water stress of plants, besides probing profiles of soil water use.

  16. Monitoring Dry Season Persistence of Anopheles gambiae s.l. Populations in a Contained Semi-Field System in Southwestern Burkina Faso, West Africa.

    Science.gov (United States)

    Mamai, W; Simard, F; Couret, D; Ouedraogo, G A; Renault, D; Dabiré, K R; Mouline, K

    2016-01-01

    To gain insight into the dry season survival strategies of Anopheles gambiae s.l., a new contained semi-field system was developed and used for the first time in Burkina Faso, West Africa. The system consisted of a screened greenhouse within which the local environment was reproduced, including all ecological requirements for mosquito development cycle completion. The system was seeded with the progenies of female Anopheles gambiae, Anopheles coluzzii, and Anopheles arabiensis collected in the vicinity of the greenhouse during the rainy season. After successful establishment in the semi-field system, mosquito populations were monitored over a 1-yr period by regular surveys of larval and adult specimens. We provided evidence for the persistence of adult mosquitoes throughout the dry season, in the absence of any suitable larval development site. During the hot and dry periods, adult insects were observed in artificial shelters (clay pots, building blocks, and dark corners). The mosquito population rapidly built up with the return of the rainy season in the area, when artificial breeding sites were refilled in the enclosure. However, only An. coluzzii and, later, An. arabiensis were detected in the subsequent rainy season, whereas no An. gambiae specimen was found. Our findings suggest that An. coluzzii and An. arabiensis may be able to aestivate throughout the dry season in Southwestern Burkina Faso, whereas An. gambiae might adopt a different dry-season survival strategy, such as long-distance re-colonization from distant locations. These results may have important implications for malaria control through targeted vector control interventions.

  17. GIS Assessment of the PM10, PM2.5 and PM1.0 Concentrations in Urban Area of Tehran in Warm and Cold Seasons

    Science.gov (United States)

    Halek, F.; Kavousi-rahim, A.

    2014-10-01

    In recent years, atmospheric models, such as GIS, are used for environmental analysis and the related management for supporting the environmental decision makers in different countries. In this study, concentrations of PM10, PM2.5 and PM1.0 are found in urban areas of Tehran in warm and cold seasons and the data applied in the related modelling, using Arc-GIS. For this purpose, samples were collected from 42 sites in an 18 km2 region located in the west and central parts of Tehran. The mean concentrations of PM1.0, PM2.5 and PM10 are found to be 13.14 μg/m3, 22.67 μg/m3 and 95.72 μg/m3 in the warm season; and 50.12 μg/m3, 70.72 μg/m3 and 193.86 μg/m3 in the cold season respectively. In this paper, with the aid of GIS, concentrations of the suspended particles were measured in 22 major hospitals, the patients in which are in contact with these pollutants. It was found the concentrations of the suspended particles were much higher in the cold season.

  18. GIS ASSESSMENT OF THE PM10, PM2.5 AND PM1.0 CONCENTRATIONS IN URBAN AREA OF TEHRAN IN WARM AND COLD SEASONS

    Directory of Open Access Journals (Sweden)

    F. Halek

    2014-10-01

    Full Text Available In recent years, atmospheric models, such as GIS, are used for environmental analysis and the related management for supporting the environmental decision makers in different countries. In this study, concentrations of PM10, PM2.5 and PM1.0 are found in urban areas of Tehran in warm and cold seasons and the data applied in the related modelling, using Arc-GIS. For this purpose, samples were collected from 42 sites in an 18 km2 region located in the west and central parts of Tehran. The mean concentrations of PM1.0, PM2.5 and PM10 are found to be 13.14 μg/m3, 22.67 μg/m3 and 95.72 μg/m3 in the warm season; and 50.12 μg/m3, 70.72 μg/m3 and 193.86 μg/m3 in the cold season respectively. In this paper, with the aid of GIS, concentrations of the suspended particles were measured in 22 major hospitals, the patients in which are in contact with these pollutants. It was found the concentrations of the suspended particles were much higher in the cold season.

  19. Ectomycorrhizal diversity and community structure in stands of Quercus oleoides in the seasonally dry tropical forests of Costa Rica

    Science.gov (United States)

    Desai, Nikhilesh S.; Wilson, Andrew W.; Powers, Jennifer S.; Mueller, Gregory M.; Egerton-Warburton, Louise M.

    2016-12-01

    Most conservation efforts in seasonally dry tropical forests have overlooked less obvious targets for conservation, such as mycorrhizal fungi, that are critical to plant growth and ecosystem structure. We documented the diversity of ectomycorrhizal (EMF) and arbuscular mycorrhizal (AMF) fungal communities in Quercus oleoides (Fagaceae) in Guanacaste province, Costa Rica. Soil cores and sporocarps were collected from regenerating Q. oleoides plots differing in stand age (early vs late regeneration) during the wet season. Sequencing of the nuclear ribosomal ITS region in EMF root tips and sporocarps identified 37 taxa in the Basidiomycota; EMF Ascomycota were uncommon. The EMF community was dominated by one species (Thelephora sp. 1; 70% of soil cores), more than half of all EMF species were found only once in an individual soil core, and there were few conspecific taxa. Most EMF taxa were also restricted to either Early or Late plots. Levels of EMF species richness and diversity, and AMF root colonization were similar between plots. Our results highlight the need for comprehensive spatiotemporal samplings of EMF communities in Q. oleoides to identify and prioritize rare EMF for conservation, and document their genetic and functional diversity.

  20. Plant hydraulic responses to long-term dry season nitrogen deposition alter drought tolerance in a Mediterranean-type ecosystem.

    Science.gov (United States)

    Pivovaroff, Alexandria L; Santiago, Louis S; Vourlitis, George L; Grantz, David A; Allen, Michael F

    2016-07-01

    Anthropogenic nitrogen (N) deposition represents a significant N input for many terrestrial ecosystems. N deposition can affect plants on scales ranging from photosynthesis to community composition, yet few studies have investigated how changes in N availability affect plant water relations. We tested the effects of N addition on plant water relations, hydraulic traits, functional traits, gas exchange, and leaf chemistry in a semi-arid ecosystem in Southern California using long-term experimental plots fertilized with N for over a decade. The dominant species were Artemisia california and Salvia mellifera at Santa Margarita Ecological Reserve and Adenostoma fasciculatum and Ceanothus greggii at Sky Oaks Field Station. All species, except Ceanothus, showed increased leaf N concentration, decreased foliar carbon to N ratio, and increased foliar N isotopic composition with fertilization, indicating that added N was taken up by study species, yet each species had a differing physiological response to long-term N addition. Dry season predawn water potentials were less negative with N addition for all species except Adenostoma, but there were no differences in midday water potentials, or wet season water potentials. Artemisia was particularly responsive, as N addition increased stem hydraulic conductivity, stomatal conductance, and leaf carbon isotopic composition, and decreased wood density. The alteration of water relations and drought resistance parameters with N addition in Artemisia, as well as Adenostoma, Ceanothus, and Salvia, indicate that N deposition can affect the ability of native Southern California shrubs to respond to drought.

  1. Coupled prediction of flood response and debris flow initiation during warm and cold season events in the Southern Appalachians, USA

    Directory of Open Access Journals (Sweden)

    J. Tao

    2013-07-01

    Full Text Available Debris flows associated with rainstorms are a frequent and devastating hazard in the Southern Appalachians in the United States. Whereas warm season events are clearly associated with heavy rainfall intensity, the same cannot be said for the cold season events. Instead, there is a relationship between large (cumulative rainfall events independently of season, and thus hydrometeorological regime, and debris flows. This suggests that the dynamics of subsurface hydrologic processes play an important role as a trigger mechanism, specifically through soil moisture redistribution by interflow. The first objective of this study is to investigate this hypothesis. The second objective is to assess the physical basis for a regional coupled flood prediction and debris flow warning system. For this purpose, uncalibrated model simulations of well-documented debris flows in headwater catchments of the Southern Appalachians using a 3-D surface-groundwater hydrologic model coupled with slope stability models are examined in detail. Specifically, we focus on two vulnerable headwater catchments that experience frequent debris flows, the Big Creek and the Jonathan Creek in the Upper Pigeon River Basin, North Carolina, and three distinct weather systems: an extremely heavy summertime convective storm in 2011; a persistent winter storm lasting several days; and a severe winter storm in 2009. These events were selected due to the optimal availability of rainfall observations, availability of detailed field surveys of the landslides shortly after they occurred, which can be used to evaluate model predictions, and because they are representative of events that cause major economic losses in the region. The model results substantiate that interflow is a useful prognostic of conditions necessary for the initiation of slope instability, and should therefore be considered explicitly in landslide hazard assessments. Moreover, the relationships between slope stability and

  2. Coupled prediction of flood response and debris flow initiation during warm and cold season events in the Southern Appalachians, USA

    Science.gov (United States)

    Tao, J.; Barros, A. P.

    2013-07-01

    Debris flows associated with rainstorms are a frequent and devastating hazard in the Southern Appalachians in the United States. Whereas warm season events are clearly associated with heavy rainfall intensity, the same cannot be said for the cold season events. Instead, there is a relationship between large (cumulative) rainfall events independently of season, and thus hydrometeorological regime, and debris flows. This suggests that the dynamics of subsurface hydrologic processes play an important role as a trigger mechanism, specifically through soil moisture redistribution by interflow. The first objective of this study is to investigate this hypothesis. The second objective is to assess the physical basis for a regional coupled flood prediction and debris flow warning system. For this purpose, uncalibrated model simulations of well-documented debris flows in headwater catchments of the Southern Appalachians using a 3-D surface-groundwater hydrologic model coupled with slope stability models are examined in detail. Specifically, we focus on two vulnerable headwater catchments that experience frequent debris flows, the Big Creek and the Jonathan Creek in the Upper Pigeon River Basin, North Carolina, and three distinct weather systems: an extremely heavy summertime convective storm in 2011; a persistent winter storm lasting several days; and a severe winter storm in 2009. These events were selected due to the optimal availability of rainfall observations, availability of detailed field surveys of the landslides shortly after they occurred, which can be used to evaluate model predictions, and because they are representative of events that cause major economic losses in the region. The model results substantiate that interflow is a useful prognostic of conditions necessary for the initiation of slope instability, and should therefore be considered explicitly in landslide hazard assessments. Moreover, the relationships between slope stability and interflow are

  3. Performance of tropical legumes grown as understory of a eucalypt plantation in a seasonally dry area of the Brazilian Cerrado

    Directory of Open Access Journals (Sweden)

    Maria Luiza F. Nicodemo

    2015-09-01

    Full Text Available Nine tropical legumes were grown outside the canopy and in the understory of an 8-year-old Eucalyptus grandis stand in order to assess their seasonal production and forage quality for 4 evaluation periods. Incident photosynthetically active radiation in the understory was 18% of that outside the canopy. In the understory, production of Lablab purpureus, Centrosema schiedeanum, Clitoria ternatea, Pueraria phaseoloides, Alysicarpus vaginalis, Aeschynomene villosa, Estilosantes Campo Grande (Stylosanthes capitata + S. macrocephala, Calopogonium mucunoides and Arachis pintoi was <1 kg/ha/d for most samples. Even considering this low production, the large area available for animal production in forest plantations might justify the interest in legumes because of their high nutritive value. Lablab purpureus produced the greatest amount of dry matter in the understory in the establishment phase (12.1 kg/ha/d, but did not persist. It could be a suitable candidate for a cover legume species mixture to provide early growth. Centrosema schiedeanum developed rapidly and showed a high capacity for ground cover (>70% and persistence, and had high nitrogen concentration, thus demonstrating good potential for protecting soils and promoting nutrient cycling in forest plantations. Another species with potential is A. pintoi, which established slowly but towards the end of the experiment showed moderate to high understory ground cover.Keywords: Dry matter production, forage quality, shade, silvopastoral system.DOI: 10.17138/TGFT(3151-160

  4. Which is the best environment for the development of the early life stages of fish during the dry season?

    Directory of Open Access Journals (Sweden)

    André Luiz Henríques Esguícero

    2010-09-01

    Full Text Available AIM: The main objective of this study was to investigate the quality of habitats for early life stages of fish in the Jacaré-Guaçu River, during the dry phase; METHODS: For assessing the quality of the habitats for the development of early life stages, the relative condition factor was applied to the juveniles of five species of fishes, captured in four different habitats (reservoir, floodplain lake, main river, and tributary. The juveniles were caught in macrophytes of the littoral zone by a rectangular sieve, in the dry season of 2008 and 2009; RESULTS: The species Astyanax altiparanae thrived similarly in the four habitats, and A. fasciatus, Hyphessobrycon eques, Hoplias malabaricus and Serrapinnus notomelas, showed higher values of relative condition factors in the reservoir and in the lake. Among the species, A. fasciatus showed the highest values of the relative condition factor in these two habitats; CONCLUSIONS: It is likely that the complexity of the macrophytes' stands and the current velocity were the main factors influencing the development of juveniles. It was found that a lower current velocity can propitiated the establishment of a greater richness of macrophytes, which in turn can influence positively the development of fish juveniles. Moreover, a higher current velocity ends in a higher energy demand for swimming.

  5. Standard Guide for Irradiation of Dried Spices, Herbs, and Vegetable Seasonings to Control Pathogens and Other Microorganisms

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2004-01-01

    1.1 This guide covers procedures for irradiation of dried spices, herbs, and vegetable seasonings for microbiological control. Generally, these items have moisture content of 4.5 to 12 % and are available in whole, ground, chopped, or other finely divided forms, or as blends. The blends may contain sodium chloride and minor amounts of dry food materials ordinarily used in such blends. 1.2 This guide covers absorbed doses ranging from 3 to 30 kiloGray (kGy). Note 1—U.S. regulations permit a maximum dose of 30 kGy. (See 21CFR 179.26 Irradiation in the Production, Processing and Handling of Food.) 1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

  6. Effects of precipitation regime and soil nitrogen on leaf traits in seasonally dry tropical forests of the Yucatan Peninsula, Mexico.

    Science.gov (United States)

    Roa-Fuentes, Lilia L; Templer, Pamela H; Campo, Julio

    2015-10-01

    Leaf traits are closely associated with nutrient use by plants and can be utilized as a proxy for nutrient cycling processes. However, open questions remain, in particular regarding the variability of leaf traits within and across seasonally dry tropical forests. To address this, we considered six leaf traits (specific area, thickness, dry matter content, N content, P content and natural abundance (15)N) of four co-occurring tree species (two that are not associated with N2-fixing bacteria and two that are associated with N2-fixing bacteria) and net N mineralization rates and inorganic N concentrations along a precipitation gradient (537-1036 mm per year) in the Yucatan Peninsula, Mexico. Specifically we sought to test the hypothesis that leaf traits of dominant plant species shift along a precipitation gradient, but are affected by soil N cycling. Although variation among different species within each site explains some leaf trait variation, there is also a high level of variability across sites, suggesting that factors other than precipitation regime more strongly influence leaf traits. Principal component analyses indicated that across sites and tree species, covariation in leaf traits is an indicator of soil N availability. Patterns of natural abundance (15)N in foliage and foliage minus soil suggest that variation in precipitation regime drives a shift in plant N acquisition and the openness of the N cycle. Overall, our study shows that both plant species and site are important determinants of leaf traits, and that the leaf trait spectrum is correlated with soil N cycling.

  7. Serum biochemical activities and muscular soreness in transported goats administered with ascorbic acid during the hot-dry season

    Directory of Open Access Journals (Sweden)

    Ndazo S Minka

    2010-12-01

    Full Text Available The effects of handling, loading and 12 h of road transportation during the hot-dry season on muscular metabolism of 20 experimental goats administered orally with 100 mg/kg body weight of ascorbic acid (AA dissolved in 10 ml of sterile water, and other 20 control goats given equivalent of sterile water 40 min prior to transportation were investigated. The result obtained post-transportation showed that handling, loading and transportation were stressful to the goats, especially the control goats and resulted into muscular damage and the development of delayed-onset-muscular-soreness (DOMS, which may lead to dark-firm-dry (DFD syndrome meat with undesirable effects on its quality. In the experimental goats administered AA such transportation effects were minimal or completely abolished. The result demonstrated that AA reduced the incidence of DOMS and muscular damage in transported goats, therefore it may be used to improve the welfare and quality of meat obtained from goats subjected to long period of road transportation under adverse climatic conditions.

  8. Symbiosis with AMF and leaf Pi supply increases water deficit tolerance of woody species from seasonal dry tropical forest.

    Science.gov (United States)

    Frosi, Gabriella; Barros, Vanessa A; Oliveira, Marciel T; Santos, Mariana; Ramos, Diego G; Maia, Leonor C; Santos, Mauro G

    2016-12-01

    In seasonal dry tropical forests, plants are subjected to severe water deficit, and the arbuscular mycorrhizal fungi (AMF) or inorganic phosphorus supply (Pi) can mitigate the effects of water deficit. This study aimed to assess the physiological performance of Poincianella pyramidalis subjected to water deficit in combination with arbuscular mycorrhizal fungi (AMF) and leaf inorganic phosphorus (Pi) supply. The experiment was conducted in a factorial arrangement of 2 water levels (+H2O and -H2O), 2 AMF levels (+AMF and -AMF) and 2Pi levels (+Pi and -Pi). Leaf primary metabolism, dry shoot biomass and leaf mineral nutrients were evaluated. Inoculated AMF plants under well-watered and drought conditions had higher photosynthesis and higher shoot biomass. Under drought, AMF, Pi or AMF+Pi plants showed metabolic improvements in photosynthesis, leaf biochemistry and higher biomass compared to the plants under water deficit without AMF or Pi. After rehydration, those plants submitted to drought with AMF, Pi or AMF+Pi showed a faster recovery of photosynthesis compared to treatment under water deficit without AMF or Pi. However, plants under the drought condition with AMF showed a higher net photosynthesis rate. These findings suggest that AMF, Pi or AMF+Pi increase the drought tolerance in P. pyramidalis, and AMF associations under well-watered conditions increase shoot biomass and, under drought, promoted faster recovery of photosynthesis. Copyright © 2016 Elsevier GmbH. All rights reserved.

  9. Relationship between dry matter production and carbon dioxide absorption in seedlings of Scots pine (Pinus silvestris L. in their second vegetation season

    Directory of Open Access Journals (Sweden)

    W. Żelawski

    2015-01-01

    Full Text Available Accumulation of dry matter in needles, lignified stems and roots during the second vegetation season was compared with seasonal changes in photosynthesis and respiration activities of the se organs. Whereas growth analysis concerned plants growing at nearly natural course of external conditions, gas exchange determinations were made at constant laboratory conditions. For comparison of dry matter production and photosynthetic ability of a plant new terms „assimilation capacity" and „efficiency of assimilation" were introduced as possible expressions of photosynthetic productivity. Two ecotypes of Scots pine originating from lowland and highland regions of the country exhibited slightly different pattern of the investigated characteristics.

  10. The role of arbuscular mycorrhizal fungi on the early-stage restoration of seasonally dry tropical forest in Chamela, Mexico

    Directory of Open Access Journals (Sweden)

    Pilar Huante

    2012-04-01

    Full Text Available It was evaluated the effect of two different sources of local inocula from two contrasting sites (mature forest, pasture of arbuscular mycorrhizae fungi (AMF and a non-mycorrhizal control on the plant growth of six woody species differing in functional characteristics (slow-, intermediate- and fast-growth, when introduced in a seasonally tropical dry forest (STDF converted into abandoned pasture. Six plots (12 X 12m were set as AMF inoculum source. Six replicates of six different species arranged in a Latin Square design were set in each plot. Plant height, cover area and the number of leaves produced by individual plant was measured monthly during the first growing season in each treatment. Species differed in their ability to benefit from AMF and the largest responsiveness in plant height and leaf production was exhibited by the slow-growing species Swietenia humilis, Hintonia latiflora and Cordia alliodora. At the end of the growing season (November, the plant height of the fast growing species Tabebuia donnel-smithii, Ceiba pentandra and Guazuma ulmifolia were not influenced by AMF. However, inocula of AMF increased leaf production of all plant species regardless the functional characteristics of the species, suggesting a better exploitation of above-ground space and generating a light limited environment under the canopy, which contributed to pasture suppression. Inoculation of seedlings planted in abandoned pasture areas is recommended for ecological restoration due to the high responsiveness of seedling growth in most of species. Use of forest inoculum with its higher diversity of AMF could accelerate the ecological restoration of the above and below-ground comunities.

  11. The establishment of Central American migratory corridors and the biogeographic origins of seasonally dry tropical forests in Mexico

    Directory of Open Access Journals (Sweden)

    Charlie George Willis

    2014-12-01

    Full Text Available Biogeography and community ecology can mutually illuminate the formation of a regional species pool or biome. We apply phylogenetic methods to a large and diverse plant clade, Malpighiaceae, to characterize the formation of its species pool in Mexico, and its occupancy of the seasonally dry tropical forest (SDTF biome that occurs there. We find that the ~162 species of Mexican Malpighiaceae represent ~33 dispersals from South America beginning in the Eocene and continuing until the Pliocene (~46.4 – 3.8 Myr. Furthermore, dispersal rates between South America and Mexico show a significant six-fold increase during the mid-Miocene (~23.9 Myr. We hypothesize that this increase marked the availability of Central America as an important corridor for Neotropical plant migration. We additionally demonstrate that this high rate of dispersal contributed substantially more to the phylogenetic diversity of Malpighiaceae in Mexico than in situ diversification. Finally, we show that most lineages arrived in Mexico pre-adapted with regard to one key SDTF trait, total annual precipitation. In contrast, these lineages adapted to a second key trait, precipitation seasonality, in situ as mountain building in the region gave rise to the abiotic parameters of extant SDTF. The timing of this in situ adaptation to seasonal precipitation suggests that SDTF likely originated its modern characteristics by the late Oligocene, but was geographically more restricted until its expansion in the mid-Miocene. These results highlight the complex interplay of dispersal, adaptation, and in situ diversification in the formation of tropical biomes. Our results additionally demonstrate that these processes are not static, and their relevance can change markedly over evolutionary time. This has important implications for understanding the origin of SDTF in Mexico, but also for understanding the temporal and spatial origin of biomes and regional species pools more broadly.

  12. The establishment of Central American migratory corridors and the biogeographic origins of seasonally dry tropical forests in Mexico.

    Science.gov (United States)

    Willis, Charles G; Franzone, Brian F; Xi, Zhenxiang; Davis, Charles C

    2014-01-01

    Biogeography and community ecology can mutually illuminate the formation of a regional species pool or biome. Here, we apply phylogenetic methods to a large and diverse plant clade, Malpighiaceae, to characterize the formation of its species pool in Mexico, and its occupancy of the seasonally dry tropical forest (SDTF) biome that occurs there. We find that the ~162 species of Mexican Malpighiaceae represent ~33 dispersals from South America beginning in the Eocene and continuing until the Pliocene (~46.4-3.8 Myr). Furthermore, dispersal rates between South America and Mexico show a significant six-fold increase during the mid-Miocene (~23.9 Myr). We hypothesize that this increase marked the availability of Central America as an important corridor for Neotropical plant migration. We additionally demonstrate that this high rate of dispersal contributed substantially more to the phylogenetic diversity of Malpighiaceae in Mexico than in situ diversification. Finally, we show that most lineages arrived in Mexico pre-adapted with regard to one key SDTF trait, total annual precipitation. In contrast, these lineages adapted to a second key trait, precipitation seasonality, in situ as mountain building in the region gave rise to the abiotic parameters of extant SDTF. The timing of this in situ adaptation to seasonal precipitation suggests that SDTF likely originated its modern characteristics by the late Oligocene, but was geographically more restricted until its expansion in the mid-Miocene. These results highlight the complex interplay of dispersal, adaptation, and in situ diversification in the formation of tropical biomes. Our results additionally demonstrate that these processes are not static, and their relevance can change markedly over evolutionary time. This has important implications for understanding the origin of SDTF in Mexico, but also for understanding the temporal and spatial origin of biomes and regional species pools more broadly.

  13. Santa Inês sheep supplementation on urochloa grass pasture during the dry season: intake, nutrient digestibility and performance

    Directory of Open Access Journals (Sweden)

    Paulo José Presídio Almeida

    2012-03-01

    Full Text Available This study was conducted with the objective of evaluating the effect of concentrate supplementation, formulated with different ingredients (Mesquite pod meal, sorghum meal or wheat meal and mineral supplementation on performance, intake and digestibility of nutrients in Santa Inês lambs grazing on urochloa grass during the dry season. Twenty-four uncastrated weaned Santa Inês sheep, with average body weight (BW 20±2 kg with an average of 120 days of age were used in the assay. The experiment lasted 75 days. The animals grazing deferred Urochloa grass (Urochloa mosambicensis (Hack Daudy were distributed into four treatments consisting of mineral supplementation provided ad libitum and concentrated supplements containing mesquite pod meal, sorghum meal or wheat meal, supplied 10 g /kg BW on dry matter basis. The intakes of dry matter (DM and crude protein (CP were affected by the intake of concentrate supplement, regardless of the ingredients used in the supplements, compared with the mineral supplementation treatment, since the consumption of forage was reduced in 30% with mesquite pod meal supplement, and neutral detergent fiber (NDF intake was not affected in relation to treatments. The digestibility of DM and CP were higher for treatments with supplements, and NDF digestibility did not differ between treatments. A significant difference was observed in the values of average daily gain for the treatments with concentrate supplementation compared with the one of mineral supplementation. The supplementation with concentrate in grazing enables improvement of performance, intake and digestibility of nutrients regardless of the ingredient used in the supplement.

  14. Dry seasons identified in oak tree-ring chronology in the Czech Lands over the last millennium

    Science.gov (United States)

    Dobrovolny, Petr; Brazdil, Rudolf; Büntgen, Ulf; Rybnicek, Michal; Kolar, Tomas; Reznickova, Ladislava; Valasek, Hubert; Kotyza, Oldrich

    2015-04-01

    from SW and low precipitation totals with higher probability of drought occurrence. Our results provide consistent physical explanation of extremely dry seasons occurring in Central Europe. However, direct comparisons of individual RW extreme seasons with existing documentary evidence show the complexity the problem as some extremes identified in oak RW chronology were not confirmed in documentary archives and vice versa. We discuss possible causes of such differences related to the fact that various proxies may have problems to record real intensity or duration of extreme events e.g. due to non-linear response of proxy data to climate drivers or due to shift in seasonality.

  15. Warm and Humidified Versus Cold and Dry CO2 Pneumoperitoneum in Minimally Invasive Colon Resection: A Randomized Controlled Trial.

    Science.gov (United States)

    Sutton, Elie; Bellini, Geoffrey; Grieco, Michael J; Kumara, H M C Shantha; Yan, Xiaohong; Cekic, Vesna; Njoh, Linda; Whelan, Richard L

    2017-10-01

    Peritoneal insufflation with warm-humidified (WH) CO2 gas during minimally invasive surgical procedures is purported to prevent hypothermia and peritoneal desiccation and is associated with decreased postoperative IL-6 levels. This randomized study's purpose was to determine the clinical impact of WH versus cold-dry (CD) CO2 in minimally invasive colon resection (MICR), and to assess perioperative plasma levels of IL-6, TIMP-1, sVEGF-R1, and HSP-70 after MICR. Operative and short-term clinical data plus perioperative blood samples were collected on MICR patients randomized to receive either WH (36.7°C, 95% humidity) or CD (room temperature, 0% humidity) CO2 perioperatively. Peritoneal biopsies were taken at the start and end of surgery. Outcomes tracked included core temperature, postoperative in-hospital pain levels, analgesia requirements, and standard recovery parameters. Preoperative and postoperative days (PODs) 1 and 3 plasma protein levels were determined via ELISA. A total of 101 patients were randomized to WH CO2 (50) or CD CO2 (51). The WH group contained more diabetics ( P = .03). There were no differences in indication, minimally invasive surgical method used, or core temperature. Pain scores were similar; however, the WH patients required less narcotics on PODs 1 to 3 ( P < .05), and less ketorolac on PODs 1 and 2 ( P < .03). No differences in length of stay, complication rates, or time to flatus/diet tolerance were noted. Plasma levels of the 4 proteins were similar postoperatively. Though insignificant, the WH group had less marked histologic changes on "end-of-case" peritoneal biopsies. This study found significantly lower pain medication requirements for PODs 1 to 3 for the WH group; however, because there were no differences in the pains scores between the groups, firm conclusions regarding WH CO2 cannot be made.

  16. CLIMATE-TREE GROWTH RELATIONSHIPS OF Mimosa tenuiflora IN SEASONALLY DRY TROPICAL FOREST, BRAZIL

    Directory of Open Access Journals (Sweden)

    Patrícia Póvoa Mattos

    2015-03-01

    Full Text Available Mimosa tenuiflora is a native pioneer tree from the Caatinga used commercially as firewood due to its high calorific value. It is deciduous, its trunk does not reach large diameters and it has good regrowth capacity. This study intended to determine the annual increment in diameter of M. tenuiflora and its correlation with rainfall, as basis for fuel wood management. Disks from the stem base of M. tenuiflora trees were collected in 2008 in Sertânia and Serra Talhada, Pernambuco State, from regrowth of trees coppiced in 2003 and in Limoeiro do Norte, Ceará State, from a plantation established in 2002. The trees have well-defined annual growth rings, highly correlated with annual precipitation and are well-suited for dendrochronological investigations. Forest managers must consider the influence of previous drier years in the wood production when predicting fuel wood harvesting. The high growth correlation with the previous year’s rainfall in regions where the rains start after photoperiodic stimulation indicate the necessity of understanding the growth dynamics of the species under dry forest conditions through additional ecophysiology studies.

  17. Dry matter accumulation and seasonal partitioning in mature Opuntia ficus-indica (L. Mill. fruiting trees

    Directory of Open Access Journals (Sweden)

    Giorgia Liguori

    2014-03-01

    Full Text Available Aim of this study was to understand the allocation of biomass into different canopy and root components and to measure the stem area index and its partitioning by cladode functionality (age, for fruiting Opuntia ficus-indica (OFI Gialla trees, spaced 6x5 m apart and trained to a globe. The net primary productivity (NPP, calculated taking into account dry weight gain for above-ground vegetative components of OFI trees was 3.6 t C ha–1. Including the fruit component and 1st flush current-year cladodes, NPP of above-ground components becomes 12 t ha–1, equivalent to 5.4 t C ha–1. Current-year cladodes were the highest C sink (49% of total annual C fixed in the canopy, secondary growth accounted for 22% of C fixation and the fruit component for 29%. This study demonstrated that OFI trees, grown in a commercial fruit orchard, couple high productivity, in terms of fruit yield and harvest index, with relevant C fixed in the canopy.

  18. On the vertical distribution of smoke in the Amazonian atmosphere during the dry season

    Science.gov (United States)

    Marenco, Franco; Johnson, Ben; Langridge, Justin M.; Mulcahy, Jane; Benedetti, Angela; Remy, Samuel; Jones, Luke; Szpek, Kate; Haywood, Jim; Longo, Karla; Artaxo, Paulo

    2016-02-01

    Lidar observations of smoke aerosols have been analysed from six flights of the Facility for Airborne Atmospheric Measurements BAe-146 research aircraft over Brazil during the biomass burning season (September 2012). A large aerosol optical depth (AOD) was observed, typically ranging 0.4-0.9, along with a typical aerosol extinction coefficient of 100-400 Mm-1. The data highlight the persistent and widespread nature of the Amazonian haze, which had a consistent vertical structure, observed over a large distance ( ˜ 2200 km) during a period of 14 days. Aerosols were found near the surface; but the larger aerosol load was typically found in elevated layers that extended from 1-1.5 to 4-6 km. The measurements have been compared to model predictions with the Met Office Unified Model (MetUM) and the ECMWF-MACC model. The MetUM generally reproduced the vertical structure of the Amazonian haze observed with the lidar. The ECMWF-MACC model was also able to reproduce the general features of smoke plumes albeit with a small overestimation of the AOD. The models did not always capture localised features such as (i) smoke plumes originating from individual fires, and (ii) aerosols in the vicinity of clouds. In both these circumstances, peak extinction coefficients of the order of 1000-1500 Mm-1 and AODs as large as 1-1.8 were encountered, but these features were either underestimated or not captured in the model predictions. Smoke injection heights derived from the Global Fire Assimilation System (GFAS) for the region are compatible with the general height of the aerosol layers.

  19. Size distributions of dicarboxylic acids, ketocarboxylic acids, α-dicarbonyls and fatty acids in atmospheric aerosols from Tanzania, East Africa during wet and dry seasons

    Directory of Open Access Journals (Sweden)

    K. Kawamura

    2012-09-01

    Full Text Available Atmospheric aerosol samples of PM2.5 and PM10 were collected during the wet and dry seasons in 2011 from a rural site in Tanzania and analysed for water-soluble dicarboxylic acids, ketocarboxylic acids, α-dicarbonyls and fatty acids using a gas chromatography (GC and GC/mass spectrometry. Here we report the size distribution and sources of diacids and related compounds for wet and dry seasons. Oxalic acid (C2 was found as the most abundant diacid species followed by succinic and/or malonic acids whereas glyoxylic acid and glyoxal were the dominant ketoacids and α-dicarbonyls, respectively in both seasons in PM2.5 and PM10. Mean concentration of C2 in PM2.5 (121.5± 46.6 ng m−3 was lower in wet season than dry season (258.1± 69.5 ng m−3. Similarly, PM10 samples showed lower concentration of C2 (168.6 ± 42.4 ng m−3 in wet season than dry season (292.4± 164.8 ng m−3. Relative abundances of C2 in total diacids were 65.4% and 67.1% in PM2.5 and 64.6% and 63.9% in PM10 in the wet and dry seasons, respectively. Total concentrations of diacids (289–362 m−3, ketoacids (37.8–53.7ng m−3, and α-dicarbonyls (5.7–7.8 ng m−3 in Tanzania are higher to those reported at a rural background site in Nylsvley (South Africa but comparable or lower to those reported from sites in Asia and Europe. Diacids and ketoacids were found to be present mainly in the fine fraction in both seasons (total α-dicarbonyls in the dry season, suggesting a production of organic aerosols from pyrogenic sources and photochemical oxidations. The averaged contributions of total diacid carbon to aerosol total carbon were 1.4% in PM2.5 and 2.1% in PM10 in wet season and 3.3% in PM2.5 and 3.9% in PM10 in dry season whereas those to water-soluble organic carbon were 2.2% and 4.7% inPM2.5 and 3.1% and 5.8% in PM10 during the wet and dry seasons, respectively. These ratios suggest an enhanced photochemical oxidation of organic precursors and heterogeneous

  20. Carriage of sub-microscopic sexual and asexual Plasmodium falciparum stages in the dry season at Navrongo, Ghana.

    Science.gov (United States)

    Atelu, Geoffrey R; Duah, Nancy O; Wilson, Michael D

    2016-12-01

    We investigated the prevalence of sub-microscopic Plasmodium falciparum infections and gametocyte carriage in asymptomatic individuals in Navrongo in northern Ghana, an area of seasonal malaria transmission. A cross sectional study of 209 randomly selected participants of all age-groups was conducted in February and March, 2015. Capillary blood samples collected from these individuals were used for the detection of both asexual and gametocyte stage parasites by microscopy, reverse transcriptase polymerase chain reaction (RT-PCR) and conventional nested PCR methods. The prevalence data as determined by microscopy and molecular methods were compared using chi-square tests. Parasitaemia from these asymptomatic infections ranged from 40 to 3,520 parasites/µl of blood (geometric mean parasitaemia = 732 parasites/µl). The prevalence of asymptomatic P. falciparum carriage was 4.8% (10/209) and 13.9% (29/209) using microscopy and RT-PCR respectively. The overall prevalence of sub-microscopic infections in the total number of samples analysed was 9.1% (19/209) and 66% (19/29) of the asymptomatic infections. P. falciparum gametocytemia detected by microscopy was 1% (2/209) and 3.8% (8/209) by PCR. This is the first report of sub-microscopic asexual and gametocytes infections in the dry season in a seasonal malaria transmission area in Ghana. It has established that persistent latent malaria infections occur and that these could supply the source of parasites for the next transmission season. The findings highlight the presence of sub-microscopic infections and therefore the need for active case detection surveillance to eliminate "asymptomatic reservoir" parasites and consequently break the transmission of the disease in Ghana. Bill and Melinda Gates Foundation grant awarded to Noguchi Memorial Institute for Medical Research Postdoctoral and Postgraduate Training in Infectious Diseases Research (Global Health Grant # OPP52155); National Institutes of Health grant (NIH

  1. Occurrence of Blastocystis sp. in water catchments at Malay villages and Aboriginal settlement during wet and dry seasons in Peninsular Malaysia

    Directory of Open Access Journals (Sweden)

    Samseh Abdullah Noradilah

    2016-10-01

    Full Text Available In the tropics, there are too few studies on isolation of Blastocystis sp. subtypes from water sources; in addition, there is also an absence of reported studies on the occurrence of Blastocystis sp. subtypes in water during different seasons. Therefore, this study was aimed to determine the occurrence of Blastocystis sp. subtypes in river water and other water sources that drained aboriginal vicinity of highly endemic intestinal parasitic infections during wet and dry seasons. Water samples were collected from six sampling points of Sungai Krau (K1–K6 and a point at Sungai Lompat (K7 and other water sources around the aboriginal villages. The water samples were collected during both seasons, wet and dry seasons. Filtration of the water samples were carried out using a flatbed membrane filtration system. The extracted DNA from concentrated water sediment was subjected to single round polymerase chain reaction and positive PCR products were subjected to sequencing. All samples were also subjected to filtration and cultured on membrane lactose glucuronide agar for the detection of faecal coliforms. During wet season, Blastocystis sp. ST1, ST2 and ST3 were detected in river water samples. Blastocystis sp. ST3 occurrence was sustained in the river water samples during dry season. However Blastocystis sp. ST1 and ST2 were absent during dry season. Water samples collected from various water sources showed contaminations of Blastocystis sp. ST1, ST2, ST3 and ST4, during wet season and Blastocystis sp. ST1, ST3, ST8 and ST10 during dry season. Water collected from all river sampling points during both seasons showed growth of Escherichia coli and Enterobacter aerogenes, indicating faecal contamination. In this study, Blastocystis sp. ST3 is suggested as the most robust and resistant subtype able to survive in any adverse environmental condition. Restriction and control of human and animal faecal contaminations to the river and other water sources

  2. Occurrence of Blastocystis sp. in water catchments at Malay villages and Aboriginal settlement during wet and dry seasons in Peninsular Malaysia

    Science.gov (United States)

    Noradilah, Samseh Abdullah; Lee, Ii Li; Anuar, Tengku Shahrul; Salleh, Fatmah Md; Abdul Manap, Siti Nor Azreen; Mohd Mohtar, Noor Shazleen Husnie; Azrul, Syed Muhamad; Abdullah, Wan Omar

    2016-01-01

    In the tropics, there are too few studies on isolation of Blastocystis sp. subtypes from water sources; in addition, there is also an absence of reported studies on the occurrence of Blastocystis sp. subtypes in water during different seasons. Therefore, this study was aimed to determine the occurrence of Blastocystis sp. subtypes in river water and other water sources that drained aboriginal vicinity of highly endemic intestinal parasitic infections during wet and dry seasons. Water samples were collected from six sampling points of Sungai Krau (K1–K6) and a point at Sungai Lompat (K7) and other water sources around the aboriginal villages. The water samples were collected during both seasons, wet and dry seasons. Filtration of the water samples were carried out using a flatbed membrane filtration system. The extracted DNA from concentrated water sediment was subjected to single round polymerase chain reaction and positive PCR products were subjected to sequencing. All samples were also subjected to filtration and cultured on membrane lactose glucuronide agar for the detection of faecal coliforms. During wet season, Blastocystis sp. ST1, ST2 and ST3 were detected in river water samples. Blastocystis sp. ST3 occurrence was sustained in the river water samples during dry season. However Blastocystis sp. ST1 and ST2 were absent during dry season. Water samples collected from various water sources showed contaminations of Blastocystis sp. ST1, ST2, ST3 and ST4, during wet season and Blastocystis sp. ST1, ST3, ST8 and ST10 during dry season. Water collected from all river sampling points during both seasons showed growth of Escherichia coli and Enterobacter aerogenes, indicating faecal contamination. In this study, Blastocystis sp. ST3 is suggested as the most robust and resistant subtype able to survive in any adverse environmental condition. Restriction and control of human and animal faecal contaminations to the river and other water sources shall prevent the

  3. Radon hazard in shallow groundwaters II: Dry season fracture drainage and alluvial fan upwelling

    Energy Technology Data Exchange (ETDEWEB)

    Tommasone, F. Pascale [Office of Civil Protection, Meteorology, Climatology and Natural Hazards, Piazza Municipio, 81051 Pietramelara, Caserta (Italy); De Francesco, S., E-mail: stefano.defrancesco@unina2.it [Department of Environmental Sciences, University of Caserta, Via Vivaldi, 43, 81100 Caserta (Italy); Cuoco, E.; Verrengia, G.; Santoro, D. [Department of Environmental Sciences, University of Caserta, Via Vivaldi, 43, 81100 Caserta (Italy); Tedesco, D. [Department of Environmental Sciences, University of Caserta, Via Vivaldi, 43, 81100 Caserta (Italy); C.N.R. (Italian National Council), Institute of Environmental Geology and Geological Engineering, Piazzale Aldo Moro, 00100 Roma (Italy)

    2011-08-15

    excellent tracer for hydrological inputs to the shallow aquifer when combined with major ions, physical-chemical data and geological and geomorphological controls. - Research highlights: {yields} We describe the seasonal variability of radon in shallow groundwaters. {yields} We report the detection of two new mechanisms of hydrological amplification of radon in shallow groundwaters. {yields} These are significant for radon hazard evaluation and earthquake-volcanic precursor studies.

  4. Temporal stability of the apparent electrical conductivity measured in seasonally dry sandy soil

    Science.gov (United States)

    Pedrera, Aura; Brevik, Eric C.; Giráldez, Juan V.; Vanderlinden, Karl

    2016-04-01

    Soil is spatially heterogeneous due to differences in parent material, climate, topography, time and management practices. The use of non-invasive and non-contact geophysical methods facilitates the exploration of natural landscapes or cropped areas. Electromagnetic induction (EMI) sensors which measure the soil apparent electrical conductivity (ECa) express soil spatial variability in terms of spatial soil ECa variability. In an agricultural context, knowledge and understanding of the soil spatial variability will allow us to delimit areas where precision agriculture techniques could be used to improve management practices. These practices enhance soil and water conservation, especially for sandy soils in Mediterranean climates where soils are dry for substantial periods of time. The first objective of this work was to apply principal component analysis (PCA) to see if a temporally stable component could be found. The second objective was to see if temporal stability information acquired from several ECa surveys could be used to better interpret results of a single survey in terms of relationships between ECa and soil water content (SWC). The experimental catchment, "La Manga", is located in SW Spain and covers 6.7 ha of a rainfed olive orchard. Soil profile samples were collected at 41 locations on a pseudo-regular grid. Samples were analyzed in the laboratory for soil texture, stone content, and bulk density (ρb). The catchment was sampled for gravimetric SWC at the 0-0.1 and 0.1-0.2 m depth intervals at the same 41 locations on 18 occasions. At the same 41 locations ECa was measured during 9 of the 18 SWC surveys using a DUALEM-21S EMI sensor. In addition, 7 field-wide ECa surveys were conducted. Soil ECa values were used to delimit three areas in the orchard, based on the spatial distribution of the first principal component (PC), which represented the spatial ECa pattern. Soil properties were studied within each area, and using analysis of variance

  5. Influence of prevailing disturbances on soil biology and biochemistry of montane habitats at Nanda Devi Biosphere Reserve, India during wet and dry seasons

    DEFF Research Database (Denmark)

    Singh, S.K.; Singh, Anoop; Rai, J.P.N.

    2011-01-01

    The impact of prevailing disturbances in montane habitats of Nanda Devi Biosphere Reserve (NDBR) was studied on soil microbial population, biomass, soil respiration and enzyme activities during wet and dry seasons. The physico-chemical characteristics of soils exhibited conspicuous variation in t...

  6. Annual Report: 2011-2012 Storm Season Sampling, Non-Dry Dock Stormwater Monitoring for Puget Sound Naval Shipyard, Bremerton, WA

    Energy Technology Data Exchange (ETDEWEB)

    Brandenberger, Jill M.; Metallo, David; Rupert, Brian; Johnston, Robert K.; Gebhart, Christine

    2013-07-03

    Annual PSNS non-dry dock storm water monitoring results for 2011-2012 storm season. Included are a brief description of the sampling procedures, storm event information, laboratory methods and data collection, a results and discussion section, and the conclusions and recommendations.

  7. Responses of landscape pattern of China's two largest freshwater lakes to early dry season after the impoundment of Three-Gorges Dam

    Science.gov (United States)

    Wu, Haipeng; Zeng, Guangming; Liang, Jie; Chen, Jin; Xu, Jijun; Dai, Juan; Sang, Lianhai; Li, Xiaodong; Ye, Shujing

    2017-04-01

    The effects of hydrologic cycle change (caused by human activity and global climate change) on ecosystems attract the increasing attention around the world. As a result of impounding of the Three Gorges Dam (TGD), climate change and sand mining, the dry season of Poyang Lake and Dongting Lake (China's two largest freshwater lakes) came early after the TGD impoundment. It was the primary cause of the increasing need for sluice/dam construction to store water in the Lakes and attracted increasing attention. In this paper, we compared the landscape pattern between three hydrologic years with early dry season (EY) and three normal hydrologic years (NY) of each lake by remote sensing technology, to reveal the effect of early dry season on landscape pattern. The results showed that early dry season caused expanding of Phalaris to mudflat zone in Poyang Lake, while caused expanding of Carex to Phalaris zone and expanding of Phalaris to mudflat zone in Dongting Lake. In landscape level, there was no significant difference in landscape grain size, landscape grain shape, habitat connectivity and landscape diversity between EY and NY in the two lakes. While in habitat class level, there were significant changes in area of mudflat and Phalaris and grain size of mudflat in Poyang Lake, and in area of Carex, grain size of Phalaris and grain shape of Carex and Phalaris in Dongting Lake. These changes will impact migrating birds of East Asian and migratory fishes of Yangtze River.

  8. African elephants adjust speed in response to surface-water constraint on foraging during the dry-season.

    Directory of Open Access Journals (Sweden)

    Simon Chamaillé-Jammes

    Full Text Available Most organisms need to acquire various resources to survive and reproduce. Individuals should adjust their behavior to make optimal use of the landscape and limit the costs of trade-offs emerging from the use of these resources. Here we study how African elephants Loxodonta africana travel to foraging places between regular visits to waterholes. Elephant herds were tracked using GPS collars during two consecutive dry seasons in Hwange National Park, Zimbabwe. We segmented each individual movement track at each visit to water to define foraging trips, and then used trip-level statistics to build an understanding of movement strategies. Travel speed within these individually-consistent movement bouts was also analyzed to understand if speed was better linked to distance to water or progression in the trip over time. We found that elephants went further from water when drinking less often, which could result from a trade-off between drinking and foraging in less depleted, far from water, places. Speed increased towards the beginning and the end of the trips, and was also greater than observed during the wet season, suggesting that elephants were trying to save time. Numerous short trips traveled at greater speed, particularly when commuting to a different waterhole, was tentatively explained by the inability to drink at specific waterholes due to intra-specific interference. Unexpectedly elephants did not always minimize travel time by drinking at the closest waterhole, but the extra distance traveled remained never more than a few kilometers. Our results show how individuals may adjust movement behavior to deal with resource trade-offs at the landscape scale. We also highlight how behavioral context, here progression in the trip, may be more important than spatial context, here distance to water, in explaining animal movement patterns.

  9. African elephants adjust speed in response to surface-water constraint on foraging during the dry-season.

    Science.gov (United States)

    Chamaillé-Jammes, Simon; Mtare, Godfrey; Makuwe, Edwin; Fritz, Hervé

    2013-01-01

    Most organisms need to acquire various resources to survive and reproduce. Individuals should adjust their behavior to make optimal use of the landscape and limit the costs of trade-offs emerging from the use of these resources. Here we study how African elephants Loxodonta africana travel to foraging places between regular visits to waterholes. Elephant herds were tracked using GPS collars during two consecutive dry seasons in Hwange National Park, Zimbabwe. We segmented each individual movement track at each visit to water to define foraging trips, and then used trip-level statistics to build an understanding of movement strategies. Travel speed within these individually-consistent movement bouts was also analyzed to understand if speed was better linked to distance to water or progression in the trip over time. We found that elephants went further from water when drinking less often, which could result from a trade-off between drinking and foraging in less depleted, far from water, places. Speed increased towards the beginning and the end of the trips, and was also greater than observed during the wet season, suggesting that elephants were trying to save time. Numerous short trips traveled at greater speed, particularly when commuting to a different waterhole, was tentatively explained by the inability to drink at specific waterholes due to intra-specific interference. Unexpectedly elephants did not always minimize travel time by drinking at the closest waterhole, but the extra distance traveled remained never more than a few kilometers. Our results show how individuals may adjust movement behavior to deal with resource trade-offs at the landscape scale. We also highlight how behavioral context, here progression in the trip, may be more important than spatial context, here distance to water, in explaining animal movement patterns.

  10. Replacement of soybean meal by soybean in multiple supplements for beef heifers grazing Urochloa decumbens during the dry season

    Directory of Open Access Journals (Sweden)

    Daniel Mageste de Almeida

    2015-12-01

    Full Text Available This study aimed to evaluate the effect of replacing soybean meal with soybean in multiple supplements on nutritional parameters, microbial efficiency and productive and reproductive performance of heifers grazing in Urochloa decumbens during the drought period. Were used 39 crossbred heifers of initial age and initial weight of 21 months and 309.5±7 kg, respectively. The experimental design was completely randomized with four treatments with eight replicates, and a control treatment with seven replications. Two treatments had soybean meal as the protein source and two treatments had soybean as the protein source, containing 25% and 40% crude protein. The amount of supplement offered was 1.0 kg/animal/day. The animals of the control group received only mineral salt ad libitum. The supplemented animals had higher average daily gain (ADG than control animals (P<0.10, and there was no difference in ADG among the supplements (P>0.10. There was an effect of supplementation (P <0.10 on intake of dry matter (DM, organic matter (OM, crude protein (CP, ether extract (EE, non-fiber carbohydrates (NFC, total digestible nutrients (TDN and neutral detergent fiber corrected for ash and protein (NDF. There were no differences (P>0.10 on intake of OM and DM grazing between the supplemented and non-supplemented. Supplementation improved DM digestibility and all constituents of the diet (P<0.10. It was found that the provision of multiple supplements optimizes the performance of heifers grazing during the dry season, and that the substitution of soybean meal by soybean did not improve productive performance of animals.

  11. Apartheid Spies: The Character, the Reader, and the Censor in André Brink’s A Dry White Season

    Directory of Open Access Journals (Sweden)

    Giuliana Iannaccaro

    2014-05-01

    Full Text Available André Brink’s novel A Dry White Season (1979 is strictly connected with the time and place in which it was written. Its dialogue with the real Johannesburg of the late Seventies is manifest: characters and plot are grafted on real events, like the youth riots in Soweto (1976 and the death of Steve Biko in the hands of the Security Police (1977. Brink’s early novels have been commended for their political commitment, but also criticized for being ‘easily’ documentary. Yet, A Dry White Season’s structure is rather complex, and its fabricated nature is shown to the reader through the device of the double internal narrator and the considerable number of ‘documents’ discovered and employed – each telling its own truth. The metaphor of the ‘spying gaze’ proposed here is useful in order to point out the interconnections between story and history, as it shows the way in which a complex and multi-layered narrative structure succeeds in both reflecting and exposing the intricate apartheid system devised to control and ‘discipline’ its own citizens. In the novel, most of the characters intrude into the life of the others and are intruded upon, included peaceful citizens who are obliged to defend themselves from an oppressive and violent police State. At the same time, also the reader is drawn into the dangerous spying game, above all when he/she is introduced into that notorious site of interrogation, torture and detention which was the Johannesburg Police Station in John Vorster Square. The last part of the essay takes into consideration the South African censorship system in force at the time, to show that the activity of surveillance is both intrinsic to the narration and external, related to the conditions of the novel’s composition and appearance on the literary market.

  12. Performance and economic viability of protein supplementation for grazing cattle steers in the wet and dry-wet transition season

    Directory of Open Access Journals (Sweden)

    Wolney Alvim Pereira Junior

    2016-02-01

    Full Text Available The objective was to evaluate performance and economic viability of protein supplementation of grazing beef cattle in the wet and dry-wet transition season. Eighty non-castrated Nellore steers, body weight of 371 ± 11.3 kg were used in the experiment. The treatments were the following: SM – Mineral supplement; Protein mineral supplements (SMP 20% FS - soybean meal: 410 g/animal; SMP 40% UR - urea: 223 g/animal; and SMP 40% UP - protect urea: 236 g/animal. It was used a complete random design with 20 replicates per treatment. There was a difference in the results (P<0.05 of PMS 40% UP compared with SM, with average daily gain (ADG of 1.06 kg/animal for SMP 40% UP and 0.95 kg/ animal for SM, respectively. There was difference (P<0.10 in the fat accumulation rate in longissimus dorsi muscle (Tx.EGLD between treatments. The PMS 40% UP supplement showed an accumulation of fat 0.018 mm/day while the SMP 40% UR had a lower rate of fat 0.011 mm/day. There was no effect (P> 0.10 of treatments on the rate of accumulation of fat in the rump region. All treatments presented a positive net margin. The best net margin was observed for treatment PMS 40% UP, that is, R$123.92 per animal/period, whereas the smallest was observed in treatment PMS 20% FS, that is, R$98.91 per animal/period. Protein supplementation with a source of protected nitrogen can be used as a strategy to increase the performance of beef cattle on pasture of Brachiaria brizantha cv. Xaraés during the wet and dry-wet transition.

  13. [Effects of nitrogen addition on available nitrogen content and acidification in cold-temperate coniferous forest soil in the growing season].

    Science.gov (United States)

    Chen, Gao-Qi; Fu, Wa-Li; Luo, Ya-Chen; Gao, Wen-Long; Li, Sheng-Gong; Yang, Hao

    2014-12-01

    Based on a low-level and multi-form N addition control experiment, this study took cold-temperate coniferous forest in Daxing'an Ling as the research object. After long-term and continuous nitrogen addition in situ, the available nitrogen (NH4(+) -N & NO3(-) -N) contents and pH values of the soil (0-10 cm) were measured in the early growing season (May) and the peak growing season (August) in 2010, 2012 and 2013. The results showed that, the available nitrogen in the early and peak growing seasons was mainly NH4(+) -N which accounted for over 96% of the inorganic nitrogen content, while the content of NO3(-) -N was very low. With the time extension of nitrogen addition, the effects of nitrogen addition on the NH4(+) -N content in 0-10 cm soil were more obvious in the early growing season than that in the peak growing season, and the NH4(+) -N content was mainly affected by the type of nitrogen addition. On the contrary, the NO3(-) -N content in 0-10 cm soil was higher in the peak growing season than that in the early growing season. The effect of N input was obvious on NO3(-) -N content in both early and peak growing seasons, and low nitrogen treatment tended to promote the enrichment of NO3(-) -N. As time went on, the response of NH4(+) -N and NO3(-) -N content to N addition was changed from insignificant in the early stage to significant in the late stage. N addition had a significant impact on the pH value of the 0-10 cm soil in the early and peak growing seasons. The pH values of the soil with low nitrogen treatment and the soil in the peak growing season were relatively lower. With the extension of the nitrogen addition time, the response of pH value also turned from insignificant in the early stage to significant in the late stage. Because of the long-term and continuous nitrogen addition, the 0 - 10 cm soil in this cold-temperate coniferous forest was obviously acidified.

  14. Sustained diurnal photosynthetic depression in uppermost-canopy leaves of four dipterocarp species in the rainy and dry seasons: does photorespiration play a role in photoprotection?

    Science.gov (United States)

    Zhang, J-L; Meng, L-Z; Cao, K-F

    2009-02-01

    Diurnal and seasonal changes in gas exchange and chlorophyll fluorescence of the uppermost-canopy leaves of four evergreen dipterocarp species were measured on clear days. The trees, that were growing in a plantation stand in southern Yunnan, China, had canopy heights ranging from 17 to 22 m. In the rainy season, Dipterocarpus retusus Bl. had higher photosynthetic capacity (A(max)) than Hopea hainanensis Merr. et Chun, Parashorea chinensis Wang Hsie and Vatica xishuangbannaensis G.D. Tao et J.H. Zhang (17.7 versus 13.9, 11.8 and 7.7 micromol m(-2) s(-1), respectively). In the dry season, A(max) in all species decreased by 52-64%, apparent quantum yield and dark respiration rate decreased in three species, and light saturation point decreased in two species. During the diurnal courses, all species exhibited sustained photosynthetic depression from midmorning onward in both seasons. The trees were able to regulate light energy allocation dynamically between photochemistry and heat dissipation during the day, with reduced actual photochemistry and increased heat dissipation in the dry season. Photorespiration played an important role in photoprotection in all species in both seasons, as indicated by a continuous increase in photorespiration rate in the morning toward midday and a high proportion of electron flow (about 30-65% of total electron flow) allocated to oxygenation for most of the day. None of the species suffered irreversible photoinhibition, even in the dry season. The sustained photosynthetic depression in the uppermost-canopy leaves of these species could be a protective response to prevent excessive water loss and consequent catastrophic leaf hydraulic dysfunction.

  15. Studies on picophytoplankton in the southern Gulf of Mexico: recognition of picoprokaryotes and abundances of picophytoplankton during "dry season"

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    Aldo Aquino-Cruz

    2013-12-01

    Full Text Available The abundance and distribution of total autotrophic picophytoplankton (PFP, temperature, salinity, PAR, and chlorophyll a were determined in two presumably contrasting environments: (1 two coastal areas (close to the mouths of three rivers, and (2 one oceanic area (Campeche Canyon, of the southern Gulf of Mexico, during the "dry season" (June-July, 2004. The picoprokaryotes Prochlorococcus and Synechococcus were identified by TEM, whereas Synechococcus and picoeukaryotes populations were also recognized by flow cytometry. The highest PFP abundance (1.67×105 cells ml-1 was found in shallow waters (~10 m depth around the Grijalva-Usumacinta river mouth, followed by that found at a station close to the Coatzacoalcos River (1.19×105 cells ml-1; PFP abundances in the Campeche Canyon were usually lower (maximum 1.53×104 cells ml-1. Greater variability in PFP abundances was found in coastal stations than in oceanic waters, and weak relationships appeared between the patterns of chlorophyll a and PFP abundance. Peaks of PFP were detected in both coastal and more oceanic areas, but in the Campeche Canyon they were located deeper (60 m, relatively closer to the deep maximum of chlorophyll (located at about 75 m. Results suggest that PFP populations include a substantial photosynthetic component in both coastal and oceanic waters of the southern Gulf of Mexico.

  16. Late dry season habitat use of common opossum, Didelphis marsupialis (Marsupialia: Didelphidae in neotropical lower montane agricultural areas

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    Christopher S. Vaughan

    1999-06-01

    Full Text Available Three Didelphis marsupialis were radio tracked during late dry season (23 February-26 April, 1983 in agricultural area at 1500 m elevation in Central Valley, Costa Rica. All animals were nocturnally active, significantly more so between 2100-0300 h. Fifty diurnal den site locations were found, 96% inside tree cavities in living fence rows or abandoned squirrel nests in windbreaks. Two females occupied 3.4 and 3.1 ha 95% home ranges, moving an average 890 and 686 m nightly respectively. The male occupied a 5.6 ha 95% home range for 42 days overlapping 90% of females' home ranges. Over the next 15 days, he moved 1020 m south, establishing three temporary home ranges. During nocturnal movements, windbreaks and living fence rows were used in higher proportion than available, while pasture, roads and cultivated lands were used less then available within 100% home ranges. Abandoned coffee and spruce plantations, fruit orchards and overgrown pastures were used in equal proportions to availability in 100% home ranges. Opossum conservation techniques in coffee growing areas include promoting spruce windbreaks, living fence rows, and garbage dumps.

  17. Critical discharge at Datong for controlling operation of South-to-North Water Transfer Project in dry seasons

    Institute of Scientific and Technical Information of China (English)

    Wang Yigang; Huang Huiming; Li Xi

    2008-01-01

    Previous research shows that there is a strong correlation between saltwater intrusion in the Yangtze Estuary and discharge at Datong. In the near future, the discharge of the Yangtze River during dry seasons will decrease due to the construction and operation of large water diversion projects, including the South-to-North Water Transfer Project, which will further exacerbate saltwater intrusion in the estuary. In this paper, a nested 1D fiver network model and a 2D saltwater numerical model are used to associate saltwater intrusion in the Yangtze Estuary with different values of discharge at Datong. It is concluded that 13 000 m3/s is the critical discharge at Datong for preventing saltwater intrusion and controlling the volume of water transferred by the South-to-North Water Transfer Project. Furthermore, based on the analysis of river discharge from Datong to Xuliujing and in consideration of the influence of all of the water diversion projects, operation schemes are proposed for the Eastern Route of the South-to-North Water Transfer Project for different hydrological years.

  18. Critical discharge at Datong for controlling operation of South-to-North Water Transfer Project in dry seasons

    Directory of Open Access Journals (Sweden)

    Wang Yigang

    2008-06-01

    Full Text Available Previous research shows that there is a strong correlation between saltwater intrusion in the Yangtze Estuary and discharge at Datong. In the near future, the discharge of the Yangtze River during dry seasons will decrease due to the construction and operation of large water diversion projects, including the South-to-North Water Transfer Project, which will further exacerbate saltwater intrusion in the estuary. In this paper, a nested 1D river network model and a 2D saltwater numerical model are used to associate saltwater intrusion in the Yangtze Estuary with different values of discharge at Datong. It is concluded that 13 000 m3/s is the critical discharge at Datong for preventing saltwater intrusion and controlling the volume of water transferred by the South-to-North Water Transfer Project. Furthermore, based on the analysis of river discharge from Datong to Xuliujing and in consideration of the influence of all of the water diversion projects, operation schemes are proposed for the Eastern Route of the South-to-North Water Transfer Project for different hydrological years.

  19. Insights into the historical construction of species-rich Mesoamerican seasonally dry tropical forests: the diversification of Bursera (Burseraceae, Sapindales).

    Science.gov (United States)

    De-Nova, J Arturo; Medina, Rosalinda; Montero, Juan Carlos; Weeks, Andrea; Rosell, Julieta A; Olson, Mark E; Eguiarte, Luis E; Magallón, Susana

    2012-01-01

    • Mesoamerican arid biomes epitomize neotropical rich and complex biodiversity. To document some of the macroevolutionary processes underlying the vast species richness of Mesoamerican seasonally dry tropical forests (SDTFs), and to evaluate specific predictions about the age, geographical structure and niche conservatism of SDTF-centered woody plant lineages, the diversification of Bursera is reconstructed. • Using a nearly complete Bursera species-level phylogeny from nuclear and plastid genomic markers, we estimate divergence times, test for phylogenetic and temporal diversification heterogeneity, test for geographical structure, and reconstruct habitat shifts. • Bursera became differentiated in the earliest Eocene, but diversified during independent early Miocene consecutive radiations that took place in SDTFs. The late Miocene average age of Bursera species, the presence of phylogenetic geographical structure, and its strong conservatism to SDTFs conform to expectations derived from South American SDTF-centered lineages. • The diversification of Bursera suggests that Mesoamerican SDTF richness derives from high speciation from the Miocene onwards uncoupled from habitat shifts, during a period of enhanced aridity resulting mainly from global cooling and regional rain shadows.

  20. Lidar Observations of Tropospheric Aerosols Over Northeastern South Africa During the ARREX and SAFARI-2000 Dry Season Experiments

    Science.gov (United States)

    Campbell, James R.; Welton, Ellsworth J.; Spinhirne, James D.; Ji, Qiang; Tsay, Si-Chee; Piketh, Stuart J.; Barenbrug, Marguerite; Holben, Brent; Starr, David OC. (Technical Monitor)

    2002-01-01

    During the ARREX-1999 and SAFARI-2000 Dry Season experiments a micropulse lidar (523 nm) instrument was operated at the Skukuza Airport in northeastern South Africa. The Mar was collocated with a diverse array of passive radiometric equipment. For SAFARI-2000 the processed Mar data yields a daytime time-series of layer mean/derived aerosol optical properties, including extinction-to-backscatter ratios and vertical extinction cross-section profile. Combined with 523 run aerosol optical depth and spectral Angstrom exponent calculations from available CIMEL sun-photometer data and normalized broadband flux measurements the temporal evolution of the near surface aerosol layer optical properties is analyzed for climatological trends. For the densest smoke/haze events the extinction-to-backscatter ratio is found to be between 60-80/sr, and corresponding Angstrom exponent calculations near and above 1.75. The optical characteristics of an evolving smoke event from SAFARI-2000 are extensively detailed. The advecting smoke was embedded within two distinct stratified thermodynamic layers, causing the particulate mass to advect over the instrument array in an incoherent manner on the afternoon of its occurrence. Surface broadband flux forcing due to the smoke is calculated, as is the evolution in the vertical aerosol extinction profile as measured by the Han Finally, observations of persistent elevated aerosol during ARREX-1999 are presented and discussed. The lack of corroborating observations the following year makes these observation; both unique and noteworthy in the scope of regional aerosol transport over southern Africa.

  1. EFFECT OF WHOLE-COTTON SEED SUPPLEMENTATION ON GROWTH PERFORMANCE AND HAEMATOLOGICAL PROPERTIES OF DJALLONKE SHEEP IN THE DRY SEASON

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    T. ANSAH

    2011-09-01

    Full Text Available An 8-week feeding trial was carried out to investigate the effect of whole-cotton seed (WCS supplementation on the growth performance and some blood constituents of Djallonke sheep fed rice straw. A total of 12 sheep with an initial weight of 13.7 ± 0.20 kg were randomly assigned to one of three treatments (four animals per treatment. The treatments consisted of no supplementation (T0 and supplementation with 200 g /head/d (T1 or 400 g/head/d (T2 on as fed basis. Feed intake, growth performance and some haematogical parameters (haemoglobin [Hb], packed cell volume [PCV], white blood cells [WBC], red blood cells [RBC] were measured. Differential leukocyte (lymphocytes, neutriphils, eosinophils, monocytes and basophils counts were also determined. Intake of basal diet was higher (P0.05. Eosinophilia increased (P>0.05 with increasing level of supplementation. This study suggests that WCS is a good source of rumen degradable protein and can help reduce the decline in growth of sheep especially in the dry season.

  2. Air quality assessment in the periurban area of Mexico Megacity during dry hot season in 2011 and 2012

    Science.gov (United States)

    Garcia-Reynoso, Agustin; Santos Garcia-Yee, Jose; Barrera-Huertas, Hugo; Gerardo Ruiz-Suárez, Luis

    2016-04-01

    Air quality is a human health threat not only in urbanized areas, it also affects the surrounding zones. Interaction between urban and rural areas can be evaluated by measurements and using models for regional areas that includes in its domain the peri-urban regions. The use of monitoring sites in remote areas is useful however it is not possible to cover all the region the use of models can provide valuable information about the source and fate of the pollution and its transformation. In order to evaluate the influence of the Mexico Megacity in the air quality of the region, two field campaigns were performed during the dry hot season during 2011 and 2012. Meterological and pollutant measurements were made during February and march 2011, in three sites towards the south east of Mexico Megacity, and from march to April 2012 towards the west after the Popocatepetl-Iztaccihuatl mountain range. Air quality modeling were performed by using the National Emissions Inventory 2008 during the studied periods, a comparison between measurements and the air quality model was performed. This type of studies can offer information about the pollutant distribution, the meteorological conditions and the exactness of emissions inventories. The latest can be useful for emissions inventory developers and policy makers.

  3. A composite sea surface temperature record of the northern South China Sea for the past 2,500 years: A unique look into seasonality and seasonal climate changes during warm and cold periods

    Science.gov (United States)

    Yan, H.; Soon, W.

    2015-12-01

    High-resolution late Holocene climate records that can resolve seasonality are essential for confirming past climatic dynamics, understanding the late 20th century global warming and predicting future climate. Here a new composite record of the sea surface temperature, SST, variation in the northern South China Sea (SCS) during the late Holocene is constructed by combining seven seasonally-resolved coral and T. gigas Sr/Ca-based SST time-windows with the instrumental SST record from modern interval between 1990 and 2000. This composite multi-proxy marine record, together with the reconstructions from mainland China and tropical western Pacific, indicates that the late Holocene warm periods, the Roman Warm Period (RWP) and Medieval Warm Period (MWP), were prominently imprinted and documented in the climatic and environmental history of the East Asia-Western Pacific region. Meanwhile, substantial and significant SST seasonality variations during the late Holocene were observed in the composite record. The observed increase in seasonality (or amplitude of seasonal cycles) during the cold periods around our study area was probably caused by the different amplitudes between winter versus summer SST variations in northern SCS, with much larger SST variation during winters than during summers for the late Holocene. In addition, the distinctive warm, cold and neutral climatic episodes identified in our northern SCS composite SST record correspond well with other paleo reconstructions from mainland China and especially well with the Northern Hemisphere-wide composites by Moberg et al. (2005) and Ljungqvist (2010). The overall agreement however also calls for more information and insights on how seasonal temperatures and their ranges vary on multidecadal to bicentennial timescales.

  4. Melatonin modulates tonic immobility and vigilance behavioural responses of broiler chickens to lighting regimens during the hot-dry season.

    Science.gov (United States)

    Sinkalu, Victor Olusegun; Ayo, Joseph O; Adelaiye, Alexander B; Hambolu, Joseph O

    2016-10-15

    Experiments were conducted with the aim of determining the influence of melatonin administration on vigilance and tonic immobility (TI) responses of Marshall broiler chickens. The broiler chickens were reared on different lighting regimens and subjected to heat stress during the hot-dry season. Simple random sampling was used to assign 300 broiler chicks into three groups, comprising 100 broiler chicks each. Group I (12D:12L cycle) was raised under natural photoperiod of 12-h light and 12-h darkness, without melatonin supplementation. Group II (CL) was kept under 24-h continuous lighting, without melatonin administration. Group III (CL+MEL) was raised under 24-h continuous lighting; with melatonin supplementation at 0.5mg/kg per os, via drinking water using a syringe. Beginning from day-old, broiler chickens in group III were individually administered with melatonin once daily for 8weeks at 17:00h. TI was induced by manual restraint, and vigilance elicited at self-righting graded for three days, two weeks apart, in 15 labeled broiler chickens from each of the three groups; at 06:00h, 13:00h and 18:00h, starting from week 4-8. Each broiler chicken was laid on its back in a U-shaped cradle, covered with cloth. Thermal microenvironment parameters of dry bulb temperature (DBT) and relative humidity (RH) were recorded at the experimental site, concurrently during the vigilance and TI tests. Inside the broiler chickens' house, the weekly temperature-humidity index (THI) was lowest at week 4 of the study, with the value of 48.60±0.08°C. At week 4, the relationship between the THI and TI induction attempts was stronger in 12D:12L cycle (r=0.589, P0.05) or CL+MEL (r=0.096, P>0.05) broiler chickens. This indicated that the broiler chickens on 12D:12L cycle were more active compared to their melatonin-treated counterparts, apparently due to adverse effects of high DBT and high RH on the broiler chickens during the hot-dry season. The highest numbers of TI induction trial

  5. Distribution of contagious and environmental mastitis agents isolated from milk samples collected from clinically health buffalo cows between brazilian dry and rainy seasons of the year

    Directory of Open Access Journals (Sweden)

    R.P. Maia

    2010-02-01

    Full Text Available The present study was performed to evaluate the microbiological characteristics of clinically health quarters submitted to milking and also to observe the distribution of contagious and environmental agents between brazilian dry and rainy seasons of the year. During nine months 734 quarters from 37 buffalo cows were submitted monthly to udder inspection, palpation and strip cup test before milking. 734 asseptic milk samples were inoculated in 10% ovine blood agar and in MacConkey agar media, then incubated for 72 hours at 37oC. Among the 580 isolated microrganisms, 182 (31,38% were recovered from samples collected during the rainy season and 398 (68,62% from the dry season. In the rainy period the most prevalent agents were: bacteria from the genus Corynebacterium sp (53,30%, Staphylococcus sp (19,78% and Rhodococcus equi (13,74%. In the dry period, the commonest ones were: Corynebacterium sp (44,97%, Staphylococcus sp (18,84% and Micrococcus sp (9,55%. The results demonstrated that the methods used to select health quarters in brazilian dairy buffalo farms allow the transmission of contagious bacteria during both seasons of the year, maintaining Ital.J.Anim.Sci. vol. 6, (Suppl. 2, 896-899, 2007 897 VIII World Buffalo Congress agents known to cause mainly subclinical inflammatory reactions that compromise cronically the physiology and production of the mammary gland.

  6. Absence of dry season Plasmodium parasitaemia, but high rates of reported acute respiratory infection and diarrhoea in preschool-aged children in Kaédi, southern Mauritania.

    Science.gov (United States)

    Touray, Sunkaru; Bâ, Hampâté; Bâ, Ousmane; Koïta, Mohamedou; Salem, Cheikh B Ould Ahmed; Keïta, Moussa; Traoré, Doulo; Sy, Ibrahima; Winkler, Mirko S; Utzinger, Jürg; Cissé, Guéladio

    2012-09-07

    The epidemiology of malaria in the Senegal River Gorgol valley, southern Mauritania, requires particular attention in the face of ongoing and predicted environmental and climate changes. While "malaria cases" are reported in health facilities throughout the year, past and current climatic and ecological conditions do not favour transmission in the dry season (lack of rainfall and very high temperatures). Moreover, entomological investigations in neighbouring regions point to an absence of malaria transmission in mosquito vectors in the dry season. Because the clinical signs of malaria are non-specific and overlap with those of other diseases (e.g. acute respiratory infections and diarrhoea), new research is needed to better understand malaria transmission patterns in this region to improve adaptive, preventive and curative measures. We conducted a multipurpose cross-sectional survey in the city of Kaédi in April 2011 (dry season), assessing three major disease patterns, including malaria. Plasmodium spp. parasite rates were tested among children aged 6-59 months who were recruited from a random selection of households using a rapid diagnostic test and microscopic examination of Giemsa-stained thick and thin blood films. Acute respiratory infection and diarrhoea were the two other diseases investigated, administering a parental questionnaire to determine the reported prevalence among participating children. No Plasmodium infection was found in any of the 371 surveyed preschool-aged children using two different diagnostic methods. Acute respiratory infections and diarrhoea were reported in 43.4% and 35.0% of the participants, respectively. About two thirds of the children with acute respiratory infections and diarrhoea required medical follow-up by a health worker. Malaria was absent in the present dry season survey in the capital of the Gorgol valley of Mauritania, while acute respiratory infections and diarrhea were highly prevalent. Surveys should be repeated

  7. Human impacts on the Changjiang (Yangtze) River basin, China, with special reference to the impacts on the dry season water discharges into the sea

    Science.gov (United States)

    Chen, Xiqing; Zong, Yongqiang; Zhang, Erfeng; Xu, Jiangang; Li, Shijie

    2001-11-01

    The annual mean discharge from the upper Changjiang (Yangtze) basin has shown a significant decreasing trend since the end of the 19th century. Since the 1970s, the monthly mean discharge to the sea has also shown a dramatic decrease during dry seasons. This paper examines the human impacts on the major hydrological processes in the Changjiang River basin, with a special focus on their influence on the discharge from the drainage basin to the sea during the dry season. Climatic warming has been obvious since the 1960s in the headwater area, resulting a continuous retreat of glaciers, while the increased evaporation is responsible for the dropping of lake water levels and decrease in water area. Such a trend continuing into the coming decades will significantly change the seasonal hydrological processes, especially the dry-season discharges from the upper basin. The decreasing vegetation cover and the increasing reservoir volume capacity also impacted on the water discharge over the past decades, although in different ways. The possible impacts of the Three Gorges Dam on the monthly variation of water discharge to the sea are discussed with special emphasis. In the middle basin discussions are focused on the effect of decreasing lake area, of increasing reservoir capacity, and of irrigated agriculture on the temporal changes of water discharge since the 1950s. The human impacts on water discharge from the lower basin to the sea are mostly attributed to water transfer to both tributary and neighboring drainage basins by a large number of electric pumping stations and sluices. The total water transferring capacity is more than 5000 m 3/s along the lower river. Studies indicate that in a dry season the water discharge to the sea is greatly reduced and results in strong saltwater intrusion in the estuary.

  8. Water availability not fruitfall modulates the dry season distribution of frugivorous terrestrial vertebrates in a lowland Amazon forest.

    Science.gov (United States)

    Paredes, Omar Stalin Landázuri; Norris, Darren; Oliveira, Tadeu Gomes de; Michalski, Fernanda

    2017-01-01

    Terrestrial vertebrate frugivores constitute one of the major guilds in tropical forests. Previous studies show that the meso-scale distribution of this group is only weakly explained by variables such as altitude and tree basal area in lowland Amazon forests. For the first time we test whether seasonally limiting resources (water and fallen fruit) affect the dry season distribution in 25 species of terrestrial vertebrates. To examine the effects of the spatial availability of fruit and water on terrestrial vertebrates we used a standardized, regularly spaced arrangement of camera-traps within 25km2 of lowland Amazon forest. Generalized linear models (GLMs) were then used to examine the influence of four variables (altitude, distance to large rivers, distance to nearest water, and presence vs absence of fruits) on the number of photos on five functional groups (all frugivores, small, medium, large and very large frugivores) and on seven of the most abundant frugivore species (Cuniculus paca, Dasyprocta leporina, Mazama americana, Mazama nemorivaga, Myoprocta acouchy, Pecari tajacu and Psophia crepitans). A total of 279 independent photos of 25 species were obtained from 900 camera-trap days. For most species and three functional groups, the variation in the number of photos per camera was significantly but weakly explained by the GLMs (deviance explained ranging from 6.2 to 48.8%). Generally, we found that the presence of water availability was more important than the presence of fallen fruit for the groups and species studied. Medium frugivores, large-bodied frugivores, and two of the more abundant species (C. paca and P. crepitans) were recorded more frequently closer to water bodies; while none of the functional groups nor the most abundant species showed any significant relationship with the presence of fallen fruit. Two functional groups and two of the seven most common frugivore species assessed in the GLMs showed significant results with species

  9. Comprehensive assessment of PM2.5 physicochemical properties during the Southeast Asia dry season (southwest monsoon)

    Science.gov (United States)

    Khan, Md Firoz; Sulong, Nor Azura; Latif, Mohd Talib; Nadzir, Mohd Shahrul Mohd; Amil, Norhaniza; Hussain, Dini Fajrina Mohd; Lee, Vernon; Hosaini, Puteri Nurafidah; Shaharom, Suhana; Yusoff, Nur Amira Yasmin Mohd; Hoque, Hossain Mohammed Syedul; Chung, Jing Xiang; Sahani, Mazrura; Mohd Tahir, Norhayati; Juneng, Liew; Maulud, Khairul Nizam Abdul; Abdullah, Sharifah Mastura Syed; Fujii, Yusuke; Tohno, Susumu; Mizohata, Akira

    2016-12-01

    A comprehensive assessment of fine particulate matter (PM2.5) compositions during the Southeast Asia dry season is presented. Samples of PM2.5 were collected between 24 June and 14 September 2014 using a high-volume sampler. Water-soluble ions, trace species, rare earth elements, and a range of elemental carbon (EC) and organic carbon were analyzed. The characterization and source apportionment of PM2.5 were investigated. The results showed that the 24 h PM2.5 concentration ranged from 6.64 to 68.2 µg m-3. Meteorological driving factors strongly governed the diurnal concentration of aerosol, while the traffic in the morning and evening rush hours coincided with higher levels of CO and NO2. The correlation analysis for non sea-salt K+-EC showed that EC is potentially associated with biomass burning events, while the formation of secondary organic carbon had a moderate association with motor vehicle emissions. Positive matrix factorization (PMF) version 5.0 identified the sources of PM2.5: (i) biomass burning coupled with sea salt [I] (7%), (ii) aged sea salt and mixed industrial emissions (5%), (iii) road dust and fuel oil combustion (7%), (iv) coal-fired combustion (25%), (v) mineral dust (8%), (vi) secondary inorganic aerosol (SIA) coupled with F- (15%), and (vii) motor vehicle emissions coupled with sea salt [II] (24%). Motor vehicle emissions, SIA, and coal-fired power plant are the predominant sources contributing to PM2.5. The response of the potential source contribution function and Hybrid Single-Particle Lagrangian Integrated Trajectory backward trajectory model suggest that the outline of source regions were consistent to the sources by PMF 5.0.

  10. White-faced monkey (Cebus capucinus ecology and management in neotropical agricultural landscapes during the dry season

    Directory of Open Access Journals (Sweden)

    Heather E. Williams

    2001-12-01

    Full Text Available Habitat use by a C. capucinus troop was studied in an agricultural landscape during late dry season (March-April 1994 in northwest Costa Rica. Riparian forests, palm canals and living fence rows accounted for 82 % of observations, significantly more than the other six habitats present. The study troop consumed 24 species of plants and five animals. Feeding concentrated on the introduced African oil palm (Elaeis guineensis (33.6 % and mango (Mangifera indica (27.2 %, found mostly in palm canals and mango orchards respectively. The troop rested between 0930-1330 hr and fed and moved between 0530-0930 hr and 1330-1730 hr. Living fence rows were used as travel routes or corridors and less intensively for other activitiesSe estudió el uso de hábitat por una tropa de C. capucinus en una zona de agricultura durante la estación seca tardía (Marzo-Abril 1994 en el noroeste de Costa Rica. Los bosques riparios, canales de palmas y cercas de árboles vivos contaron con el 82 % de las observaciones, significantemente más que los otros seis hábitats presentes. La tropa de estudio consumió 24 especies de plntas y cinco animales. La alimentación se concentró en la palma de aceite Africana introducida (Elaeis guineensis (33.6 % y en mango (Mangifera indica (27.2 %, encontrados principalmente en los canales de palmas y huertos de mango respectivamente. La tropa descansó entre las 0930-1330 hr y se alimentó y movió entre las 0530-0930 hr y 1330-730 hr. Las cercas de árboles vivos fueron usadas como rutas de paso o corredores y menos intensamente para otras actividades

  11. Mating system, population growth, and management scenario for Kalanchoe pinnata in an invaded seasonally dry tropical forest.

    Science.gov (United States)

    González de León, Salvador; Herrera, Ileana; Guevara, Roger

    2016-07-01

    Ecological invasions are a major issue worldwide, where successful invasion depends on traits that facilitate dispersion, establishment, and population growth. The nonnative succulent plant Kalanchoe pinnata, reported as invasive in some countries, is widespread in remnants of seasonally dry tropical forest on a volcanic outcrop with high conservation value in east-central Mexico where we assessed its mating system and demographic growth and identified management strategies. To understand its local mating system, we conducted hand-pollination treatments, germination, and survival experiments. Based on the experimental data, we constructed a life-stage population matrix, identified the key traits for population growth, weighted the contributions of vegetative and sexual reproduction, and evaluated management scenarios. Hand-pollination treatments had slight effects on fruit and seed setting, as well as on germination. With natural pollination treatment, the successful germination of seeds from only 2/39 fruit suggests occasional effective natural cross-pollination. The ratios of the metrics for self- and cross-pollinated flowers suggest that K. pinnata is partially self-compatible. Most of the pollinated flowers developed into fruit, but the seed germination and seedling survival rates were low. Thus, vegetative propagation and juvenile survival are the main drivers of population growth. Simulations of a virtual K. pinnata population suggest that an intense and sustained weeding campaign will reduce the population within at least 10 years. Synthesis and applications. The study population is partially self-compatible, but sexual reproduction by K. pinnata is limited at the study site, and population growth is supported by vegetative propagation and juvenile survival. Demographic modeling provides key insights and realistic forecasts on invasion process and therefore is useful to design management strategies.

  12. A coupled phylogeographical and species distribution modelling approach recovers the demographical history of a Neotropical seasonally dry forest tree species.

    Science.gov (United States)

    Collevatti, Rosane G; Terribile, Levi Carina; Lima-Ribeiro, Matheus S; Nabout, João C; de Oliveira, Guilherme; Rangel, Thiago F; Rabelo, Suelen G; Diniz-Filho, Jose A F

    2012-12-01

    We investigated here the demographical history of Tabebuia impetiginosa (Bignoniaceae) to understand the dynamics of the disjunct geographical distribution of South American seasonally dry forests (SDFs), based on coupling an ensemble approach encompassing hindcasting species distribution modelling and statistical phylogeographical analysis. We sampled 17 populations (280 individuals) in central Brazil and analysed the polymorphisms at chloroplast (trnS-trnG, psbA-trnH, and ycf6-trnC intergenic spacers) and nuclear (ITS nrDNA) genomes. Phylogenetic analyses based on median-joining network showed no haplotype sharing among population but strong evidence of incomplete lineage sorting. Coalescent analyses showed historical constant populations size, negligible gene flow among populations, and an ancient time to most recent common ancestor dated from ~4.7 ± 1.1 Myr BP. Most divergences dated from the Lower Pleistocene, and no signal of important population size reduction was found in coalescent tree and tests of demographical expansion. Demographical scenarios were built based on past geographical range dynamic models, using two a priori biogeographical hypotheses ('Pleistocene Arc' and 'Amazonian SDF expansion') and on two additional hypotheses suggested by the palaeodistribution modelling built with several algorithms for distribution modelling and palaeoclimatic data. The simulation of these demographical scenarios showed that the pattern of diversity found so far for T. impetiginosa is in consonance with a palaeodistribution expansion during the last glacial maximum (LGM, 21 kyr BP), strongly suggesting that the current disjunct distribution of T. impetiginosa in SDFs may represent a climatic relict of a once more wide distribution.

  13. Assessment of dry season surface, ground, and treated water quality in the Cape Coast municipality of Ghana.

    Science.gov (United States)

    Quagraine, E K; Adokoh, C K

    2010-01-01

    This aim of this monitoring was to assess water quality in a dry season for the Cape Coast municipality in Ghana, which has been experiencing chronic water shortages. Fifteen different sampling stations--four surface, five ground, and six tap water samples--were analyzed for physicochemical and microbiological parameters during January to April 2005. Levels or trends in water quality that may be deleterious to sensitive water uses, including drinking, irrigation, and livestock watering have been noted with reference to well-established guidelines. Exceedances to some health-based drinking water guidelines included positive coliform for various water samples; pH for all groundwater samples (pH 5.9+/-0.3); conductivity for 50% groundwater; color for about a third of groundwater and tap water; Mn for 44% tap water, 67% groundwater, and 50% surface water samples. The World Health Organization laundry staining Fe guideline of 0.3 mg/l was exceeded by 75% of surface water, 44% tap water, and 53% groundwater samples. The corresponding Mn guideline of 0.1 mg/l was exceeded by all the water samples. Respectively, all surface water samples and also 75% of the surface water exceeded some known Cu and Zn guideline for the protection of aquatic life. Compared to some historic data for Fosu Lagoon, the current study shows a lowering of approximately 1 pH unit, increase of approximately 65% NH3, one to two orders of magnitude increase in PO4(3-), and more than two orders of magnitude increase in NO3-. In several instances, tap water samples collected at the consumers' end of the distribution system did not reflect on the true quality of the treated water. Mn, SO4(2-), PO4(3-), Cu, and Zn were among the chemical contaminations observed to occur in the distribution system.

  14. The role of edaphic environment and climate in structuring phylogenetic pattern in seasonally dry tropical plant communities.

    Science.gov (United States)

    Moro, Marcelo Freire; Silva, Igor Aurélio; de Araújo, Francisca Soares; Nic Lughadha, Eimear; Meagher, Thomas R; Martins, Fernando Roberto

    2015-01-01

    Seasonally dry tropical plant formations (SDTF) are likely to exhibit phylogenetic clustering owing to niche conservatism driven by a strong environmental filter (water stress), but heterogeneous edaphic environments and life histories may result in heterogeneity in degree of phylogenetic clustering. We investigated phylogenetic patterns across ecological gradients related to water availability (edaphic environment and climate) in the Caatinga, a SDTF in Brazil. Caatinga is characterized by semiarid climate and three distinct edaphic environments - sedimentary, crystalline, and inselberg -representing a decreasing gradient in soil water availability. We used two measures of phylogenetic diversity: Net Relatedness Index based on the entire phylogeny among species present in a site, reflecting long-term diversification; and Nearest Taxon Index based on the tips of the phylogeny, reflecting more recent diversification. We also evaluated woody species in contrast to herbaceous species. The main climatic variable influencing phylogenetic pattern was precipitation in the driest quarter, particularly for herbaceous species, suggesting that environmental filtering related to minimal periods of precipitation is an important driver of Caatinga biodiversity, as one might expect for a SDTF. Woody species tended to show phylogenetic clustering whereas herbaceous species tended towards phylogenetic overdispersion. We also found phylogenetic clustering in two edaphic environments (sedimentary and crystalline) in contrast to phylogenetic overdispersion in the third (inselberg). We conclude that while niche conservatism is evident in phylogenetic clustering in the Caatinga, this is not a universal pattern likely due to heterogeneity in the degree of realized environmental filtering across edaphic environments. Thus, SDTF, in spite of a strong shared environmental filter, are potentially heterogeneous in phylogenetic structuring. Our results support the need for scientifically

  15. The Role of Edaphic Environment and Climate in Structuring Phylogenetic Pattern in Seasonally Dry Tropical Plant Communities

    Science.gov (United States)

    Moro, Marcelo Freire; Silva, Igor Aurélio; de Araújo, Francisca Soares; Nic Lughadha, Eimear; Meagher, Thomas R.; Martins, Fernando Roberto

    2015-01-01

    Seasonally dry tropical plant formations (SDTF) are likely to exhibit phylogenetic clustering owing to niche conservatism driven by a strong environmental filter (water stress), but heterogeneous edaphic environments and life histories may result in heterogeneity in degree of phylogenetic clustering. We investigated phylogenetic patterns across ecological gradients related to water availability (edaphic environment and climate) in the Caatinga, a SDTF in Brazil. Caatinga is characterized by semiarid climate and three distinct edaphic environments – sedimentary, crystalline, and inselberg –representing a decreasing gradient in soil water availability. We used two measures of phylogenetic diversity: Net Relatedness Index based on the entire phylogeny among species present in a site, reflecting long-term diversification; and Nearest Taxon Index based on the tips of the phylogeny, reflecting more recent diversification. We also evaluated woody species in contrast to herbaceous species. The main climatic variable influencing phylogenetic pattern was precipitation in the driest quarter, particularly for herbaceous species, suggesting that environmental filtering related to minimal periods of precipitation is an important driver of Caatinga biodiversity, as one might expect for a SDTF. Woody species tended to show phylogenetic clustering whereas herbaceous species tended towards phylogenetic overdispersion. We also found phylogenetic clustering in two edaphic environments (sedimentary and crystalline) in contrast to phylogenetic overdispersion in the third (inselberg). We conclude that while niche conservatism is evident in phylogenetic clustering in the Caatinga, this is not a universal pattern likely due to heterogeneity in the degree of realized environmental filtering across edaphic environments. Thus, SDTF, in spite of a strong shared environmental filter, are potentially heterogeneous in phylogenetic structuring. Our results support the need for scientifically

  16. Carbon monoxide and related trace gases and aerosols over the Amazon Basin during the wet and dry seasons

    Directory of Open Access Journals (Sweden)

    M. O. Andreae

    2012-07-01

    Full Text Available We present the results of airborne measurements of carbon monoxide (CO and aerosol particle number concentration (CN made during the Balanço Atmosférico Regional de Carbono na Amazônia (BARCA program. The primary goal of BARCA is to address the question of basin-scale sources and sinks of CO2 and other atmospheric carbon species, a central issue of the Large-scale Biosphere-Atmosphere (LBA program. The experiment consisted of two aircraft campaigns during November–December 2008 (BARCA-A and May–June 2009 (BARCA-B, which covered the altitude range from the surface up to about 4500 m, and spanned most of the Amazon Basin.

    Based on meteorological analysis and measurements of the tracer, SF6, we found that airmasses over the Amazon Basin during the late dry season (BARCA-A, November 2008 originated predominantly from the Southern Hemisphere, while during the late wet season (BARCA-B, May 2009 low-level airmasses were dominated by northern-hemispheric inflow and mid-tropospheric airmasses were of mixed origin. In BARCA-A we found strong influence of biomass burning emissions on the composition of the atmosphere over much of the Amazon Basin, with CO enhancements up to 300 ppb and CN concentrations approaching 10 000 cm−3; the highest values were in the southern part of the Basin at altitudes of 1–3 km. The ΔCN/ΔCO ratios were diagnostic for biomass burning emissions, and were lower in aged than in fresh smoke. Fresh emissions indicated CO/CO2 and CN/CO emission ratios in good agreement with previous work, but our results also highlight the need to consider the residual smoldering combustion that takes place after the active flaming phase of deforestation fires.

    During the late wet season, in contrast, there was little evidence for a significant presence of biomass smoke. Low CN concentrations (300–500 cm−3 prevailed basinwide, and CO mixing ratios were enhanced

  17. Parity Differences in Heat Expression of Dairy Cows Synchronized with GnRH, CIDR and PGF2α during Dry Season in Zambia

    Directory of Open Access Journals (Sweden)

    E. S. Mwaanga*, K. Choongo, H. Simukoko and C. Chama1

    2012-01-01

    Full Text Available A study was conducted to investigate parity differences in heat expression of dairy cows heat-synchronized during the dry season when feed scarcity is common. Cyclic cows (n=65 aged 2 to 10 years with parity range of 0 to 7 were selected from small-holder dairy farms around Lusaka. Cows were divided into 3 groups of nulliparous, primiparous and pluriparous. Heat-was synchronized using gonadotrophin releasing hormone (GnRH and controlled intra-vaginal drug releasing device (CIDR. Heat detection was observed after CIDR withdraw. The study showed a significantly (P<0.05 lower number of primiparous cows (68% coming into heat compared to nulliparous (81.8% and pluriparous cows (83.3%. It was concluded that parity influences estrus expression rate in dairy cows following synchronization with GnRH, CIDR and PGF2α during the dry season in the sub-tropics.

  18. Pattern of pre-existing IgG subclass responses to a panel of asexual stage malaria antigens reported during the lengthy dry season in Daraweesh, Sudan

    DEFF Research Database (Denmark)

    Nasr, A; Iriemenam, N C; Troye-Blomberg, M

    2011-01-01

    The anti-malarial IgG immune response during the lengthy and dry season in areas of low malaria transmission as in Eastern Sudan is largely unknown. In this study, ELISA was used for the measurement of pre-existing total IgG and IgG subclasses to a panel of malaria antigens, MSP2-3D7, MSP2-FC27, ...

  19. Water discharge changes of the Changjiang River downstream Datong during dry season%长江大通-河口段枯季的径流量变化

    Institute of Scientific and Technical Information of China (English)

    张二凤; 陈西庆; 王晓丽

    2003-01-01

    Based on hydrometric data and extensive investigations on water-extracting projects, thispaper presents a preliminary study on water discharge changes between Datong and Xuliujing duringdry season. The natural hydrological processes and human factors that influence the water dischargeare analyzed with the help of GIS method. The investigations indicate that the water-extractingprojects downstream from Datong to Xuliujing had amounted to 64 in number by the end of 2000,with a water-extracting capacity up to 4,626 m3/s averaged in a tidal cycle. The water extraction fromthe Changjiang River has become the most important factor influencing the water dischargedownstream Datong during dry season. The potential magnitude in water discharge changes areestimated based on historical records of water extraction and a water balance model. Thecomputational results were calibrated with the actual data. The future trend in changes of waterdischarge into the sea during dry season was discussed by taking into consideration of newly builthydro-engineering projects. The water extraction downstream Datong in dry season before 2000 had agreat influence on discharges into the sea in the extremely dry year like 1978-1979. It produced a netdecrease of more than 490 m3/s in monthly mean discharges from the Changjiang into the sea. It isexpected that the water extraction will continually increase in the coming decades, especially in dryyears, when the net decrease in monthly mean water discharge will increase to more than 1000 m3/sand will give a far-reaching effect on the changes of water discharge from the Changjiang into thesea.

  20. Monitoring ambient air pollutants and apply Woods' model in the prediction seasonal dry deposition at Chang-Hua (urban) and Kao-Mei (wetland) county, Taiwan.

    Science.gov (United States)

    Fang, Guor-Cheng; Chang, Chia-Ying

    2014-09-01

    The main purpose for this study was to monitor ambient air particles and metallic elements (Mn, Fe, Zn, Cr, Cu and Pb) in total suspended particulate (TSP) concentration and dry deposition. In addition, the calculated/measured dry deposition flux ratios of ambient air particles and metallic elements (Mn, Fe, Zn, Cr, Cu and Pb) were evaluated using Woods' model at urban and wetland areas for the 2009-2010 period. The results indicated that the mean highest concentrations of metallic elements Mn, Fe, Zn, Cr, Cu and Pb in TSP were found in Chang-Hua (urban) sampling site. And as for the two characteristic sampling sites, the Woods' model exhibits better dry deposition of particulates of 18 µm particle size than the rest of the other particle sizes at any sampling site in this study. The average calculated/measured flux ratios for two seasons (summer and fall) by using Woods model at 2.5, 10 and 18 µm particles sizes were also studied. The results indicated that the average calculated/measured flux ratios orders for two seasons of various particles sizes were all displayed as Fe > Mn > Zn > Cu > Cr > Pb > particle. And these calculated/measured flux ratios orders were Fe > Mn > Cu > Zn > Cr > Pb > particle and were Fe > Mn > Zn > Cu > Cr > particle > Pb, during spring and winter seasons, respectively. Finally, in the spring and summer seasons of Gao-Mei (wetland) sampling site, the average calculated/measured flux ratios using Woods' model was found to be 2.5, 10 and 18 µm, showing the order of the calculated/measured flux ratios to be Fe > Cu > Zn > Mn > Cr > Pb > particle. And the calculated/measured flux ratio orders were Fe > Zn > Mn > Cu > Cr > particle > Pb and were Fe > Cu > Zn > Mn > Cr > particle > Pb for fall and winter season, respectively.

  1. Performance of small-scale dairy farms in the highlands of central Mexico during the dry season under traditional feeding strategies.

    Science.gov (United States)

    Martínez-García, Carlos Galdino; Rayas-Amor, Adolfo Armando; Anaya-Ortega, Juan Pablo; Martínez-Castañeda, Francisco Ernesto; Espinoza-Ortega, Angélica; Prospero-Bernal, Fernando; Arriaga-Jordán, Carlos Manuel

    2015-02-01

    In Mexico, small-scale dairy systems (SSDS) represent over 78 % of dairy farms and contribute with 37 % of national milk production; however, they face high feeding costs. The objective of this study was to assess the performance of SSDS during the dry season in terms of milk yields, milk composition and feeding costs under traditional feeding strategies, to identify areas of opportunity for improving their profitability. The information was collected from 22 SSDS every month during dry season. Feeds were classified in quality forages (QF), supplements (SU) and straws (ST). Two factors were identified: factor 1-a positive relationship among QF, SU, milk yield and ration cost and factor 2-represented straw usage. Four feeding strategies were identified: (1) low-cost feeding strategy; (2) home-grown feeding strategy; (3) high-cost feeding strategy; and (4) straw-based feeding strategy. There were differences (P  0.05) differences among feeding strategies for fat and protein contents in milk. It is concluded that to improve performance and profitability and enhance sustainability in SSDS, farmers should base feeding strategies on home-grown quality forages, as it was the case in group 2 which showed lower feeding cost and better milk yield. It is also recommended to increase the inclusion of quality forages like grazing pastures and maize silages during the dry season and to avoid the inclusion of straws.

  2. Balance characteristics of multivariate background error covariance for rainy and dry seasons and their impact on precipitation forecasts of two rainfall events

    Science.gov (United States)

    Chen, Yaodeng; Xia, Xue; Min, Jinzhong; Huang, Xiang-Yu; Rizvi, Syed R. H.

    2016-10-01

    Atmospheric moisture content or humidity is an important analysis variable of any meteorological data assimilation system. The humidity analysis can be univariate, using humidity background (normally short-range numerical forecasts) and humidity observations. However, more and more data assimilation systems are multivariate, analyzing humidity together with wind, temperature and pressure. Background error covariances, with unbalanced velocity potential and humidity in the multivariate formulation, are generated from weather research and forecasting model forecasts, collected over a summer rainy season and a winter dry season. The unbalanced velocity potential and humidity related correlations are shown to be significantly larger, indicating more important roles unbalanced velocity potential and humidity play, in the rainy season than that in the dry season. Three cycling data assimilation experiments of two rainfall events in the middle and lower reaches of the Yangtze River are carried out. The experiments differ in the formulation of the background error covariances. Results indicate that only including unbalanced velocity potential in the multivariate background error covariance improves wind analyses, but has little impact on temperature and humidity analyses. In contrast, further including humidity in the multivariate background error covariance although has a slight negative effect on wind analyses and a neutral effect on temperature analyses, but significantly improves humidity analyses, leading to precipitation forecasts more consistent with China Hourly Merged Precipitation Analysis.

  3. Biogeochemical generation of dissolved inorganic carbon and nitrogen in the North Branch of inner Changjiang Estuary in a dry season

    Science.gov (United States)

    Zhai, Wei-Dong; Yan, Xiu-Li; Qi, Di

    2017-10-01

    We investigated the surface water carbonate system, nutrients, and relevant hydrochemical parameters in the inner Changjiang (Yangtze River) Estuary in early spring 2009 and 2010. The two surveys were carried out shortly after spring-tide days, and covered both the channel-like South Branch and the freshwater-blocked North Branch. In the North Branch, with a water residence time of approximately one month, we detected remarkable partial pressures of CO2 (pCO2) of 930-1518 μatm with a salinity range of 4.5-17.4, which were substantially higher than the South Branch pCO2 values of 700-1100 μatm at salinities of less than 0.88. The North Branch pCO2 distribution pattern is unique compared with many other estuaries where aquatic pCO2 normally declines with salinity increase. Furthermore, the biogeochemical additions of ammonium (7.4-65.7 μmol kg-1) and alkalinity (196-695 μmol kg-1) were identified in salinities between 4 and 16 in the North Branch. Based on field data analyses and simplified stoichiometric equations, we suggest that the relatively high North Branch pCO2 values and estuarine additions of dissolved inorganic nitrogen/carbon in the mid-salinity area were strongly associated with each other. These signals were primarily controlled by biogeochemical processes in the North Branch, combining biogenic organic matter decomposition (i.e. respiration), ammonia oxidation, CaCO3 dissolution, and CO2 degassing. In the upper reach of the South Branch, notable salinity values of 0.20-0.88 were detected, indicating saltwater spillover from the North Branch. These spillover waters had minor contributions (1.5-6.9%) to the springtime nutrient, dissolved inorganic carbon, and alkalinity export fluxes from Changjiang to the adjacent East China Sea. This is the first attempt to understand the biogeochemical controls of the unique pCO2 distributions in the North Branch, and to evaluate the effects of saltwater spillover from the North Branch on dry-season export fluxes

  4. Snail Farming in Mature Rubber Plantation : 4. Studies on some Artificial Methods for Hatching of Snail Eggs and Protection of Young Snails during the Dry Season

    Directory of Open Access Journals (Sweden)

    Awah, AA.

    2001-01-01

    Full Text Available Three species of edible land snails of the moist forest belt of Nigeria, Archachatina marginata (Swainson, Archachatina papyracae (Pfeiffer and two phenotypes of Limicolaria species, sometimes named Limicolaria flammae (Muller and Limicolaria aurora (Jay, were used in the study of three methods of artificial hatching of snail eggs and their young ones for the study of two methods of reduction of mortality during the dry season. The results of egg laying performance by the three species of snails showed a significantly (p <0.01 higher population explosion in a given breeding season for L. flammae/aurora than for either A. papyracae or A. marginata. The results of artificial methods for hatching of snail eggs indicated that the use of plastic containers, plus either loose topsoil or cotton wool for the incubator mediums or the use of cellophane containers (bag plus loose topsoil for the incubator medium, were in each case suitable for adoption in successful hatching of snail eggs artificially. Leaking coagulation pans or wooden boxes, half filled with heat sterilized loose topsoil and placed on the ground under shade of rubber tree canopy as dry season protection methods for the snails, were again in each case effective in the reduction of field mortality of the young snails. The survival rates were 100 % ; 90.6 % and 71.2 % for youngs of A. marginata, A. papyracae and L. flammae/aurora respectively. The results further indicated that the dry season protection method deemed optimum for the youngs of A. marginata may not necessarily be optimum for the youngs of either A. papyracae orL. flammae/aurora.

  5. Seasonal variations in species diversity, dry matter and net primary productivity of herb layer of Quercus leucotrichophora-Pinus roxburghii mixed forest in Kumaun Himalaya, India

    Institute of Scientific and Technical Information of China (English)

    Mukesh Joshi; Y.S.Rawat; J.Ram

    2012-01-01

    Plant biomass,species diversity and net primary productivity are presented for herb layer of banj oak (Quercus leucotrichophora A.Camus)-chir pine (Pinus roxburghii Sarg.) mixed forest in Kumaun,central Himalaya,India.The species diversity declined from a maximum (3.56) in September to a minimum (2.11) in December.The monthly live shoots biomass exhibited a single peak growth pattern with highest live shoot biomass of 185 g·m-2 in August.The seasonal pattern showed that the maximum above-ground production (131 g·m-2) occurred during the rainy season and the minimum (1 g·m-2) during winter season.The below-ground production was maximum during winter season (84 g·m-2) and minimum during summer season (34 g·m-2).The annual net shoot production was 171 g·m-2 and total below-ground production was 165 g·m-2.Of the total input 61% was channeled to above-ground parts and 39% to below-ground parts.Transfer of live shoots to dead shoots compartments and that of dead shoots to litter compartments was 61% and 66%,respectively.The total dry matter disappearance was 61% of the total input within annual cycle.The herb layer showed a net accumulation of organic matter,indicating the seral nature of the community.

  6. Absence of dry season Plasmodium parasitaemia, but high rates of reported acute respiratory infection and diarrhoea in preschool-aged children in Kaédi, southern Mauritania

    Directory of Open Access Journals (Sweden)

    Touray Sunkaru

    2012-09-01

    Full Text Available Abstract Background The epidemiology of malaria in the Senegal River Gorgol valley, southern Mauritania, requires particular attention in the face of ongoing and predicted environmental and climate changes. While “malaria cases” are reported in health facilities throughout the year, past and current climatic and ecological conditions do not favour transmission in the dry season (lack of rainfall and very high temperatures. Moreover, entomological investigations in neighbouring regions point to an absence of malaria transmission in mosquito vectors in the dry season. Because the clinical signs of malaria are non-specific and overlap with those of other diseases (e.g. acute respiratory infections and diarrhoea, new research is needed to better understand malaria transmission patterns in this region to improve adaptive, preventive and curative measures. Methods We conducted a multipurpose cross-sectional survey in the city of Kaédi in April 2011 (dry season, assessing three major disease patterns, including malaria. Plasmodium spp. parasite rates were tested among children aged 6–59 months who were recruited from a random selection of households using a rapid diagnostic test and microscopic examination of Giemsa-stained thick and thin blood films. Acute respiratory infection and diarrhoea were the two other diseases investigated, administering a parental questionnaire to determine the reported prevalence among participating children. Findings No Plasmodium infection was found in any of the 371 surveyed preschool-aged children using two different diagnostic methods. Acute respiratory infections and diarrhoea were reported in 43.4% and 35.0% of the participants, respectively. About two thirds of the children with acute respiratory infections and diarrhoea required medical follow-up by a health worker. Conclusions Malaria was absent in the present dry season survey in the capital of the Gorgol valley of Mauritania, while acute respiratory

  7. Modeling of basin-wide water management for dry-season paddy irrigation with large reservoirs in the Mekong River Basin

    Science.gov (United States)

    Kudo, R.; Masumoto, T.; Horikawa, N.; Yoshida, T.

    2012-12-01

    Northeast Thailand, one of the regions in the Mekong River Basin, has less rainfall than adjacent countries and its rainfall is heavily concentrated in rainy seasons (almost 90% of annual rainfall). Therefore, this area is characterized as semi-arid region especially during dry seasons. In this region, rain-fed paddies account for about 90% and this leads to unstable rice production. Against these backgrounds, a number of large irrigation projects have been carried out since the 1970s to increase agricultural productivity. In these projects, a lot of irrigation facilities such as large/medium reservoirs, diversion weirs and irrigation canals were constructed for stable water supply in dry seasons. These projects enable farmers to pursue double rice cropping as rainy- and dry-season cropping in this region. Paddy field irrigation, however, exerts a great influence on water circulation of river basins in Monsoon Asia and modeling of these processes is crucial to understand the hydrological cycle especially in areas where irrigated agriculture is dominant. In this study, to quantify the hydrological cycle in irrigation-dominant basins, we applied a distributed hydrological model incorporating paddy irrigation schemes to the Mun River Basin, one of the tributaries of the Mekong River, in Northeast Thailand, and analyzed water circulation considering complex water use by agricultural activities. The model used in this study consists of four sub-models, such as referential evapotranspiration, cropping pattern/area, agricultural water use, and runoff model in order to estimate various information on agricultural water use. Additionally, water allocation and reservoir operation models were integrated into the hydrological model to account for the water circulation in large irrigation areas. For the analysis, the basin is divided into 10km-mesh and each mesh contains the ratio of 5 land-use category as forest, rain-fed paddy, irrigated paddy, upland field and water area

  8. Seasonal variation in expression pattern of genes under HSP70 : Seasonal variation in expression pattern of genes under HSP70 family in heat- and cold-adapted goats (Capra hircus).

    Science.gov (United States)

    Banerjee, Dipak; Upadhyay, Ramesh C; Chaudhary, Umesh B; Kumar, Ravindra; Singh, Sohanvir; Ashutosh; G, Jagan Mohanarao; Polley, Shamik; Mukherjee, Ayan; Das, Tapan K; De, Sachinandan

    2014-05-01

    Heat shock protein 70 (HSP70) is one of the most abundant and best characterized heat shock protein family that consists of highly conserved stress proteins, expressed in response to stress, and plays crucial roles in environmental stress tolerance and adaptation. The present study was conducted to identify major types of genes under the HSP70 family and to quantify their expression pattern in heat- and cold-adapted Indian goats (Capra hircus) with respect to different seasons. Five HSP70 gene homologues to HSPA8, HSPA6, HSPA1A, HSPA1L, and HSPA2 were identified by gene-specific primers. The cDNA sequences showed high similarity to other mammals, and proteins have an estimated molecular weight of around 70 kDa. The expression of HSP70 genes was observed during summer and winter. During summer, the higher expression of HSPA8, HSPA6, and HSPA1A was observed, whereas the expression levels of HSPA1L and HSPA2 were found to be lower. It was also observed that the expression of HSPA1A and HSPA8 was higher during winter in both heat- and cold-adapted goats but downregulates in case of other HSPs. Therefore, both heat and cold stress induced the overexpression of HSP70 genes. An interesting finding that emerged from the study is the higher expression of HSP70 genes in cold-adapted goats during summer and in heat-adapted goats during winter. Altogether, the results indicate that the expression pattern of HSP70 genes is species- and breed-specific, most likely due to variations in thermal tolerance and adaptation to different climatic conditions.

  9. Soil dehydrogenase in a land degradation-rehabilitation gradient: observations from a savanna site with a wet/dry seasonal cycle.

    Science.gov (United States)

    Doi, Ryoichi; Ranamukhaarachchi, Senaratne Leelananda

    2009-01-01

    Soil dehydrogenase activity is a good indicator of overall microbial activity in soil, and it can serve as a good indicator of soil condition. However, seasonal changes in soil moisture content may have an effect on soil dehydrogenase activity, making an accurate assessment of soil condition difficult. In this study, we attempted to determine the significance of soil dehydrogenase activity for assessing soil condition, and we attempted to find a way to account for the influence of soil moisture content on soil dehydrogenase activity.' Soils were sampled in dry evergreen forest (original vegetation), bare ground (severely degraded) and Acacia plantation plots established on bare ground in 1986 and 1987 in Sakaerat, Thailand. Soil physico-chemical characteristics and dehydrogenase activity in the Acacia plantation soil had few differences from those in the evergreen forest soil. Soil dehydrogenase activity varied significantly between the bare ground and the forests regardless of the season (wet or dry), while the season did not produce a significant variation in soil dehydrogenase activity, as determined by repeated measures analysis of variance (p=0.077). The physico-chemical data provided the first principal component as a good measure of soil fertility. Values of soil dehydrogenase activity significantly correlated to scores of the soil samples of the first principal component (R=0.787, pThailand.

  10. Physical, chemical and microbiological aspects during the dry and rainy seasons in a pond covered by macrophyte used in aquaculture water supply

    Directory of Open Access Journals (Sweden)

    Samuel Generoso Dias

    Full Text Available AIM: The water quality of a pond covered by macrophytes and used as a water supply for aquaculture was evaluated during the dry and rainy seasons; METHODS: Six points were established for water sampling, at water inflow and outflow. Samplings were carried out monthly between June 2008 and May 2009; RESULTS: Inflow points P1, P2 and P3 in the pond had higher nutrient concentrations and high trophic rates. Moreover, capybaras in the area caused sediment suspension and an increase in fecal coliforms. There was significant difference (p < 0.05 in the concentrations of nutrients in water between the dry and rainy seasons. The outflow of water caused by rain carried the material around the pond directly into the water; CONCLUSIONS: The system studied was influenced by rain and lack of adequate management of the surrounding area. Water quality was deteriorated by increase in nutrient concentrations, fecal coliforms and reduction of dissolved oxygen in the water during the rainy season. This was due to allochthonous material from the area surrounding the pond that affected negatively the supply system.

  11. Combining two-dimensional gel electrophoresis and metabolomic data in support of dry-season survival in the two main species of the malarial mosquito Anopheles gambiae

    Directory of Open Access Journals (Sweden)

    Hidalgo K.

    2015-12-01

    Full Text Available In dry savannahs of West-Africa, the malarial mosquitoes of the Anopheles gambiae sensu stricto complex annually survive the harsh desiccating conditions of the dry season. However, the physiological and biochemical mechanisms underlying how these mosquitoes survive such desiccating conditions are still undefined, and controversial. In this context, we provide the first work examining both proteomic and metabolomic changes in the two molecular forms of A. gambiae s.s (M and S forms experimentally exposed to the rainy and dry season conditions as they experience in the field. Protein abundances of the mosquitoes were measured using a two-dimensional fluorescence difference gel electrophoresis (2D DIGE coupled with a matrix-assisted laser desorption/ionisation-time of flight (MALDI-TOF and tandem mass spectrometry (MS for protein identification. These assays were conducted by Applied Biomics (http://www.appliedbiomics.com, Applied Biomics, Inc. Hayward, CA, USA, and the mass spectrometry proteomics data have been deposited to the ProteomeXchange Consortium (http://proteomecentral.proteomexchange.org via the PRIDE partner repository with the dataset identifier PXD000294. The metabolomic analysis was conducted using both Acquity UPLC® system (for amino acid identification, and a gas-chromatography-mass spectrometry platform (for sugars identification. Metabolomic fingerprintings were assessed in the University of Rennes 1, UMR CNRS 6553 EcoBio (France. A detailed interpretation of the obtained data can be found in Hidalgo et al. (2014 [1] (Journal of Insect Physiology (2014.

  12. ABSORBTION DRYING-EVAPORATIVE HEAT USING SYSMEMS FOR COLD PRODUCTION WITH THE USE OF ALTERNATIVE ENERGY SOURCES

    Directory of Open Access Journals (Sweden)

    Doroshenko A.V.

    2010-12-01

    Full Text Available Direct and indirect evaporative coolers with nozzles based on multi channel and multi layer polymeric structures are examined in the paper. Such coolers can be used in both independent and combined variants, as well as a part of solar drying-evaporative systems. Heat required for the regeneration of absorbent is provided with solar energy from flat solar collectors from polymeric materials.

  13. Damage escape and repair in dried Chroococcidiopsis spp. from hot and cold deserts exposed to simulated space and martian conditions.

    Science.gov (United States)

    Billi, Daniela; Viaggiu, Emanuela; Cockell, Charles S; Rabbow, Elke; Horneck, Gerda; Onofri, Silvano

    2011-01-01

    The cyanobacterium Chroococcidiopsis, overlain by 3 mm of Antarctic sandstone, was exposed as dried multilayers to simulated space and martian conditions. Ground-based experiments were conducted in the context of Lichens and Fungi Experiments (EXPOSE-E mission, European Space Agency), which were performed to evaluate, after 1.5 years on the International Space Station, the survival of cyanobacteria (Chroococcidiopsis), lichens, and fungi colonized on Antarctic rock. The survival potential and the role played by protection and repair mechanisms in the response of dried Chroococcidiopsis cells to ground-based experiments were both investigated. Different methods were employed, including evaluation of the colony-forming ability, single-cell analysis of subcellular integrities based on membrane integrity molecular and redox probes, evaluation of the photosynthetic pigment autofluorescence, and assessment of the genomic DNA integrity with a PCR-based assay. Desiccation survivors of strain CCMEE 123 (coastal desert, Chile) were better suited than CCMEE 134 (Beacon Valley, Antarctica) to withstand cellular damage imposed by simulated space and martian conditions. Exposed dried cells of strain CCMEE 123 formed colonies, maintained subcellular integrities, and, depending on the exposure conditions, also escaped DNA damage or repaired the induced damage upon rewetting.

  14. Trade-offs between global warming and day length on the start of the carbon uptake period in seasonally cold ecosystems

    Science.gov (United States)

    Wohlfahrt, Georg; Cremonese, Edoardo; Hammerle, Albin; Hörtnagl, Lukas; Galvagno, Marta; Gianelle, Damiano; Marcolla, Barbara; Cella, Umberto Morra

    2013-12-01

    is well established that warming leads to longer growing seasons in seasonally cold ecosystems. Whether this goes along with an increase in the net ecosystem carbon dioxide (CO2) uptake is much more controversial. We studied the effects of warming on the start of the carbon uptake period (CUP) of three mountain grasslands situated along an elevational gradient in the Alps. To this end, we used a simple empirical model of the net ecosystem CO2 exchange, calibrated, and forced with multiyear empirical data from each site. We show that reductions in the quantity and duration of daylight associated with earlier snowmelts were responsible for diminishing returns, in terms of carbon gain, from longer growing seasons caused by reductions in daytime photosynthetic uptake and increases in nighttime losses of CO2. This effect was less pronounced at high, compared to low, elevations, where the start of the CUP occurred closer to the summer solstice when changes in day length and incident radiation are minimal.

  15. Proteomic characterization of freeze-dried human plasma: providing treatment of bleeding disorders without the need for a cold chain.

    Science.gov (United States)

    Steil, Leif; Thiele, Thomas; Hammer, Elke; Bux, Jürgen; Kalus, Monika; Völker, Uwe; Greinacher, Andreas

    2008-11-01

    Transfusion of human plasma is a basic treatment for severe coagulopathies, especially in major bleeding. The required logistics to provide plasma is challenging because of the need to maintain a cold chain. This disadvantage could be overcome by lyophilized plasma. However, it is unknown to what extent lyophilization alters plasma proteins. Quantitative proteomic technologies were applied to monitor protein changes during production of lyophilized, solvent/detergent (S/D)-treated plasma. The impact of S/D treatment and lyophilization on the plasma proteome was evaluated by differential in-gel electrophoresis (2D-DIGE), and proteins were characterized by mass spectrometry. Clotting factor activities were determined in lyophilized S/D-treated plasma after 24 months of storage at room temperature. By 2D-DIGE, 600 individual protein spots were compared. Lyophilization did not change any of the 600 spots, whereas pathogen inactivation caused significant changes of 38 spots including alpha1-antitrypsin, alpha1-antichymotrypsin, and alpha2-antiplasmin. Clotting factor activities remained stable over 24 months of storage. Lyophilization of human plasma neither alters its protein composition nor impairs its clotting capacity. It does not require cost-intensive logistics for storage and transport and can be quickly reconstituted. It is suggested that lyophilized, pathogen-inactivated plasma is an attractive option to provide the most important basic treatment for severe coagulopathies in areas without cold chain and to provide plasma with reduced time delay in emergency situations.

  16. Considerations on Temperature Inversions in the Lower Troposphere in the 2001-2002 Cold Season, South of the Carpathian Mountains

    Directory of Open Access Journals (Sweden)

    Florentina Bărcăcianu

    2014-10-01

    Full Text Available Temperature inversions are characterized by negative vertical thermal gradients (Donciu, 1953, Ţâştea, 1965, Bogdan, 1971, Neacşa, Frimescu, 1981. The most frequent manifestation is in the depression areas because in addition to radiative cooling and better possibility to store cold air invasion, it also takes place the accumulation and of air flow of cold air due to gravity. The area south of the Carpathians, shows depression features, gaining titles like: carpathianbalkanic bucket (Bălescu, 1962, carpathian-balkanic sink (Ion-Bordei, N. 1988. In this space the inversions occupy the entire area, proof being the values from low altitude stations similar to those from mountain peaks, while the middle part of the slope remains wormer.

  17. Cholesterol-lowering and lipid oxidation reduction potentials of traditional seasonings in Salchichon dry-fermented sausages.

    Science.gov (United States)

    Seong, Pil-Nam; Seo, Hyun-Woo; Lee, Ga-Young; Cho, Soo-Hyun; Kim, Yoon-Seok; Kang, Sun-Moon; Kim, Jin-Hyoung; Park, Beom-Young; Van-Ba, Hoa

    2016-08-01

    Five different natural/traditional seasonings including doenjang (fermented soybean paste), gochu-jang (red pepper paste), fresh medium-hot and hot peppers, and garlic were used, and 1 % (w/w) each was incorporated into formulations of Salchichon fermented sausage type. After ripening for 51 days, the products were assessed for quality parameters, lipid oxidation, cholesterol content and sensory characteristics. In general, incorporation of the seasonings did not cause color or texture defects whereas it had beneficial effects on improvement of product's quality; however the effects differed depending on each type of seasonings added. Noticeably, most treatments with the seasonings significantly reduced the lipid oxidation. Additionally, incorporating doenjang, gochu-jang, medium-hot peppers, hot peppers and garlic resulted in reduction of 32.03, 28.96, 36.30, 19.53 and 33.03 mg cholesterol/100 g sample, corresponding to 26.78, 24.21, 30.35, 16.33 and 27.61 %, respectively. Higher scores for the sensory traits such as aroma, taste, color and acceptability were also observed for the samples with seasonings. The current work demonstrated that the tested seasonings represent potentially natural ingredients for producing healthier Salchichon fermented sausages.

  18. Application of drip irrigation technology for producing fruit of Salak ‘Gula Pasir’ (Salacca zalacca var. Gula Pasir off season on dry land

    Directory of Open Access Journals (Sweden)

    I N Rai

    2014-10-01

    Full Text Available Naturally, Salak Gula Pasir (Salacca zalacca var. Gula Pasir is flowering every three months or four times a year, but only one or two flowering seasons that the flowers can develop into fruit. The condition causes Salak Gula Pasir is available in the market in a short period (only 2-3 months i.e. at the time of harvest (on-season from December to February. This seasonal nature of Salak Gula Pasir occurs because Salak Gula Pasir is planted on dry land where irrigation depends only on rainfall, and drought occurs when water is shortage so that the plant internal water content is low that causes a high failure development rate of flower to become fruit (fruit-set failure. This study was aimed to overcome the fruit-set failure by providing drip irrigation. Two treatments (with drip irrigation and without drip irrigation/control with sixteen replicates were tested at Salak Gula Pasir production centre (at Sibetan village, Bebandem District, of Karangasem Regency, Bali at two harvest seasons, i.e. Gadu (July and Sela II (October. The results showed that the plant provided with drip irrigation significantly yielded fruit-set percentage higher that that without drip irrigation, both in Gadu and Sela II seasons. The percentages of fruit-set in Gadu and Sela II seasons provided with drip irrigation were 75.30% and 93.13%, respectively, while those without drip irrigation were only 59.94% and 61.67%, respectively. The increase of fruit-set observed for drip irrigation treatment associated with the increase of leaf chlorophyll content, relative water content (RWC of leaves, and leaf N, P, and K contents. The increase of fruit-set led to higher number of fruits and fruit weight per plant under drip irrigation than that without drip irrigation. Based on the results of this study, drip irrigation can be applied to produce Salak Gula Pasir planted out of season on dry land.

  19. An objective tropical Atlantic sea surface temperature gradient index for studies of south Amazon dry-season climate variability and change.

    Science.gov (United States)

    Good, Peter; Lowe, Jason A; Collins, Mat; Moufouma-Okia, Wilfran

    2008-05-27

    Future changes in meridional sea surface temperature (SST) gradients in the tropical Atlantic could influence Amazon dry-season precipitation by shifting the patterns of moisture convergence and vertical motion. Unlike for the El Niño-Southern Oscillation, there are no standard indices for quantifying this gradient. Here we describe a method for identifying the SST gradient that is most closely associated with June-August precipitation over the south Amazon. We use an ensemble of atmospheric general circulation model (AGCM) integrations forced by observed SST from 1949 to 2005. A large number of tropical Atlantic SST gradient indices are generated randomly and temporal correlations are examined between these indices and June-August precipitation averaged over the Amazon Basin south of the equator. The indices correlating most strongly with June-August southern Amazon precipitation form a cluster of near-meridional orientation centred near the equator. The location of the southern component of the gradient is particularly well defined in a region off the Brazilian tropical coast, consistent with known physical mechanisms. The chosen index appears to capture much of the Atlantic SST influence on simulated southern Amazon dry-season precipitation, and is significantly correlated with observed southern Amazon precipitation. We examine the index in 36 different coupled atmosphere-ocean model projections of climate change under a simple compound 1% increase in CO2. Within the large spread of responses, we find a relationship between the projected trend in the index and the Amazon dry-season precipitation trends. Furthermore, the magnitude of the trend relationship is consistent with the inter-annual variability relationship found in the AGCM simulations. This suggests that the index would be of use in quantifying uncertainties in climate change in the region.

  20. Different Patterns of Changes in the Dry Season Diameter at Breast Height of Dominant and Evergreen Tree Species in a Mature Subtropical Forest in South China

    Institute of Scientific and Technical Information of China (English)

    Jun-Hua Yan; Guo-Yi Zhou; De-Qiang Zhang; Xu-Li Tang; Xu Wang

    2006-01-01

    Information on changes in diameter at breast height (DBH) is important for net primary production (NPP)estimates, timing of forest inventory, and forest management. In the present study, patterns of DBH change were measured under field conditions during the dry season for three dominant and native tree species in a monsoon evergreen broad-leaved forest in the Dinghushan Biosphere Reserve. For each tree species,different patterns of DBH change were observed. In the case of the fast-growing tree species Castanopsis chinensis Hance, large diurnal fluctuations occur, with a peak DBH in the early morning (around 05:00 h) that decreases to a minimum by about 14:00 h. Both Schima superba Gardn. et Chemp and Cryptocarya chinensis (Hance) Hemsl. exhibited less diurnal swelling and shrinkage. Diurnal fluctuations for these species were observed on a few occasions over the period of observation. Graphical comparisons and statistical analysis of changes in DBH with meteorological variables indicate that for different trees, the different changes in DBH observed responded to different meteorological variables. Large stem changes were found to occur for Ca. chinensis trees that were associated with variations in solar radiation. However, both S. superba and Cr. chinensis were found to be less sensitive to solar radiation. Changes in the DBH of these two species were found to be controlled mainly by soil temperature and soil moisture. During the later dry season, with a lower soil temperature and soil moisture, all three tree species stopped growing and only negligible shrinkage, expansion, or fluctuation occurred, suggesting that the optimum time to measure tree growth in the Dinghushan Biosphere Reserve is the later dry season.

  1. Observation studies on the influence of atmospheric boundary layer characteristics associate with air quality in dry season over the Pearl River Delta, China

    Science.gov (United States)

    Fan, Shaojia; Wu, Meng; Li, Haowen; Liao, Zhiheng; Fan, Qi; Zhu, Wei

    2016-04-01

    The characteristics of atmospheric boundary layer (ABL) is the very important factors influence on air quality in dry season over the Pearl River Delta (PRD), China. Based on the sounding data at six stations (Xinken,Dongguan, Sanshui, Nanhai, Shunde, and Heshan) which obtained from three times ABL experiments carried in dry season over PRD, the influence of wind and temperature vertical structure to the air quality over PRD has been studied with wind and temperature profiles, inversion layer, recirculation factor (RF), atmospheric boundary layer height (ABLH) and ventilation index (VI). It was found that the vertical wind of PRD could be divided in typical three layers according two wind shears appeared in 800 m and 1300 m. The thickness of calm or lower wind speed layer in pollution days was 500-1000m thicker than that of clean days, and its last time also much longer than that of clean days. The frequency of surface inversion in pollution days was about 35%,the mean thickness was about 100 m. With the influence of sea breeze, the frequency and thickness of surface inversion layer at Xinken station was a little lower than that in inland. Influenced by sea-land breezes and urban heat-island circulation, the RF of pollution days in coastal and urban area was quite smaller than that of clean days. During sea-land breezes days, the pollutants would be transported back to inland in nighttime with the influence of sea breeze, and resulted in 72.7% sea-land breezes was pollution days. The evolution of ABL was very typical in PRD during dry season. In pollution days, daily ABLH in PRD was lower than 500 m, daily VI was about 500-1500 m2/s. In clean days, daily VI was much larger than 2500 m2/s. An improved conceptual model of ABL influence on poor air quality and the parameters of the ABL characteristics associate with poor air quality in dry season over PRD had been summarized.

  2. Short communication: Reference limits for blood analytes in Holstein late-pregnant heifers and dry cows: Effects of parity, days relative to calving, and season.

    Science.gov (United States)

    Brscic, M; Cozzi, G; Lora, I; Stefani, A L; Contiero, B; Ravarotto, L; Gottardo, F

    2015-11-01

    Reference limits for metabolic profiles in Holstein late-pregnant heifers and dry cows were determined considering the effects of parity, days relative to calving, and season. Blood samples were collected from 104 pregnant heifers and 186 dry cows (68 primiparous and 118 pluriparous) from 60 to 10 d before the expected calving date in 31 dairy farms in northeastern Italy. Sampling was performed during summer (182 samples) and the following winter (108 samples). All the animals were judged as clinically healthy at a veterinary visit before sampling. Outliers were removed from data of each blood analyte, and variables that were not normally distributed were log transformed. A mixed model was used to test the fixed effects of parity (late-pregnant heifers, primiparous or pluriparous dry cows), class of days relative to calving (60-41 d, 40-21 d, 20-10 d), season (summer or winter), and the interactions between parity and class of days relative to calving and between parity and season, with farm as random effect. Single general reference limits and 95% confidence intervals were generated for analytes that did not vary according to fixed effects. Whenever a fixed effect included in the model significantly affected a given analyte, specific reference limits and 95% confidence intervals were generated for each of its levels. Albumin, urea, triglycerides, alanine aminotransferase, aspartate aminotransferase, creatinine kinase, conjugated bilirubin, calcium, phosphorus, magnesium, potassium, chloride, zinc, copper, and iron concentrations were not influenced by any of the fixed effects. Total protein, globulins, creatinine, glucose, alkaline phosphatase, gamma glutamyltransferase, lactate dehydrogenase, and sodium plasma concentrations were affected by parity. The class of days relative to calving had a significant effect on the concentrations of total protein, globulins, fatty acids, cholesterol, total bilirubin, and sodium. Season affected plasma concentrations of

  3. Large-scale vertical velocity, diabatic heating and drying profiles associated with seasonal and diurnal variations of convective systems observed in the GoAmazon2014/5 experiment

    OpenAIRE

    Tang, Shuaiqi; Xie, Shaocheng; Zhang, Yunyan; Zhang, Minghua; Schumacher, Courtney; Upton, Hannah; Jensen, Michael P.; Johnson, Karen L.; Wang, Meng; Ahlgrimm, Maike; Feng, Zhe; Minnis, Patrick; Thieman, Mandana

    2016-01-01

    This study describes the characteristics of large-scale vertical velocity, apparent heating source (Q1) and apparent moisture sink (Q2) profiles associated with seasonal and diurnal variations of convective systems observed during the two intensive operational periods (IOPs) that were conducted from 15 February to 26 March 2014 (wet season) and from 1 September to 10 October 2014 (dry season) near Manaus, Brazil, during the Green Ocean Amazon (GoAmazon2014/5) experiment. The...

  4. Seasonal changes in daily metabolic patterns of Tegu lizards (tupinambis merianae) placed in the cold (17 C) and dark

    DEFF Research Database (Denmark)

    Milsom, William K.; Andrade, Denis V.; Brito, Simone P.;

    2008-01-01

    Oxygen consumption rate was measured continuously in young tegu lizards Tupinambis merianae exposed to 4 d at 25°C followed by 7-10 d at 17°C in constant dark at five different times of the year. Under these conditions, circadian rhythms in the rate of oxygen consumption persisted for anywhere from......). Although this degree of reduction appeared to take longer to invoke when starting from higher metabolic rates, tegu lizards reduced their metabolism to the low rates seen in winter dormancy at all times of the year when given sufficient time in the cold and dark. In the spring and summer, tegus reduced...

  5. Large-scale vertical velocity, diabatic heating and drying profiles associated with seasonal and diurnal variations of convective systems observed in the GoAmazon2014/5 experiment

    Science.gov (United States)

    Tang, Shuaiqi; Xie, Shaocheng; Zhang, Yunyan; Zhang, Minghua; Schumacher, Courtney; Upton, Hannah; Jensen, Michael P.; Johnson, Karen L.; Wang, Meng; Ahlgrimm, Maike; Feng, Zhe; Minnis, Patrick; Thieman, Mandana

    2016-11-01

    This study describes the characteristics of large-scale vertical velocity, apparent heating source (Q1) and apparent moisture sink (Q2) profiles associated with seasonal and diurnal variations of convective systems observed during the two intensive operational periods (IOPs) that were conducted from 15 February to 26 March 2014 (wet season) and from 1 September to 10 October 2014 (dry season) near Manaus, Brazil, during the Green Ocean Amazon (GoAmazon2014/5) experiment. The derived large-scale fields have large diurnal variations according to convective activity in the GoAmazon region and the morning profiles show distinct differences between the dry and wet seasons. In the wet season, propagating convective systems originating far from the GoAmazon region are often seen in the early morning, while in the dry season they are rarely observed. Afternoon convective systems due to solar heating are frequently seen in both seasons. Accordingly, in the morning, there is strong upward motion and associated heating and drying throughout the entire troposphere in the wet season, which is limited to lower levels in the dry season. In the afternoon, both seasons exhibit weak heating and strong moistening in the boundary layer related to the vertical convergence of eddy fluxes. A set of case studies of three typical types of convective systems occurring in Amazonia - i.e., locally occurring systems, coastal-occurring systems and basin-occurring systems - is also conducted to investigate the variability of the large-scale environment with different types of convective systems.

  6. TrMADS3, a new MADS-box gene, from a perennial species Taihangia rupestris (Rosaceae) is upregulated by cold and experiences seasonal fluctuation in expression level.

    Science.gov (United States)

    Du, Xiaoqiu; Xiao, Qiying; Zhao, Ran; Wu, Feng; Xu, Qijiang; Chong, Kang; Meng, Zheng

    2008-06-01

    In many temperate perennial plants, floral transition is initiated in the first growth season but the development of flower is arrested during the winter to ensure production of mature flowers in the next spring. The molecular mechanisms of the process remain poorly understood with few well-characterized regulatory genes. Here, a MADS-box gene, named as TrMADS3, was isolated from the overwintering inflorescences of Taihangia rupestris, a temperate perennial in the rose family. Phylogenetic analysis reveals that TrMADS3 is more closely related to the homologs of the FLOWERING LOCUS C lineage than to any of the other MIKC-type MADS-box lineages known from Arabidopsis. The TrMADS3 transcripts are extensively distributed in inflorescences, roots, and leaves during the winter. In controlled conditions, the TrMADS3 expression level is upregulated by a chilling exposure for 1 to 2 weeks and remains high for a longer period of time in warm conditions after cold treatment. In situ hybridization reveals that TrMADS3 is predominantly expressed in the vegetative and reproductive meristems. Ectopic expression of TrMADS3 in Arabidopsis promotes seed germination on the media containing relatively high NaCl or mannitol concentrations. These data indicate that TrMADS3 in a perennial species might have its role in both vegetative and reproductive meristems in response to cold.

  7. Performance of the Enhanced Vegetation Index to Detect Inner-annual Dry Season and Drought Impacts on Amazon Forest Canopies

    NARCIS (Netherlands)

    Brede, B.; Verbesselt, J.; Dutrieux, L.; Herold, M.

    2015-01-01

    The Amazon rainforests represent the largest connected forested area in the tropics and play an integral role in the global carbon cycle. In the last years the discussion about their phenology and response to drought has intensified. A recent study argued that seasonality in greenness expressed as E

  8. Performance of the Enhanced Vegetation Index to Detect Inner-annual Dry Season and Drought Impacts on Amazon Forest Canopies

    NARCIS (Netherlands)

    Brede, B.; Verbesselt, J.; Dutrieux, L.; Herold, M.

    2015-01-01

    The Amazon rainforests represent the largest connected forested area in the tropics and play an integral role in the global carbon cycle. In the last years the discussion about their phenology and response to drought has intensified. A recent study argued that seasonality in greenness expressed as

  9. Performance of the Enhanced Vegetation Index to Detect Inner-annual Dry Season and Drought Impacts on Amazon Forest Canopies

    NARCIS (Netherlands)

    Brede, B.; Verbesselt, J.; Dutrieux, L.; Herold, M.

    2015-01-01

    The Amazon rainforests represent the largest connected forested area in the tropics and play an integral role in the global carbon cycle. In the last years the discussion about their phenology and response to drought has intensified. A recent study argued that seasonality in greenness expressed as E

  10. Intercropped oats (Avena sativa) - common vetch (Vicia sativa) silage in the dry season for small-scale dairy systems in the highlands of central Mexico.

    Science.gov (United States)

    Garduño-Castro, Y; Espinoza-Ortega, A; González-Esquivel, C E; Mateo-Salazar, B; Arriaga-Jordán, C M

    2009-06-01

    Small-scale dairy systems in the highlands of central Mexico require feeding strategies based on quality home-grown forage that may reduce high concentrate costs. Eight Holstein cows paired by parity and date of calving were used in a split-plot experiment to evaluate supplementing 6 kg DM/cow/d of oat-vetch silage (OVS) in comparison to maize silage (MS) as dry season feeding, for a more intensive use of the land through an oat-vetch catch crop. Cows had 9 h/d access to continuous grazing of perennial ryegrass - white clover pasture and 4 kg/d of commercial concentrate. The 9 week experiment, recorded weekly milk yield and composition, and body condition score and live-weight every fortnight. Milk yield was 20.1 kg/cow/d for OVS and 15.4 for MS (SEM +/-2.9, P > 0.05), with no differences for fat or protein content, body condition score, or live-weight (P > 0.05). The economic analysis showed that although feeding costs were higher for OVS, margins were greater than for MS, with feeding cost per litre of $0.21 for MS and $0.16 for OVS. OVS is a viable catch crop after the MS harvest that can substitute MS in the dry season enabling a more intensive use of the land.

  11. Comparison of protein and energy supplementation to mineral supplementation on feeding behavior of grazing cattle during the rainy to the dry season transition.

    Science.gov (United States)

    Brandão, Rita Kelly Couto; de Carvalho, Gleidson Giordano Pinto; Silva, Robério Rodrigues; Dias, Daniel Lucas Santos; Mendes, Fabrício Bacelar Lima; Lins, Túlio Otávio Jardim D'Almeida; Filho, George Abreu; de Souza, Sinvaldo Oliveira; Barroso, Daniele Soares; de Almeida Rufino, Luana Marta; Tosto, Manuela Silva Libânio

    2016-01-01

    The aim of this study was to evaluate the effects of protein-energy or mineral supplementation on the ingestive behavior of dairy steers on pasture in the post-weaning phase during the rainy to dry season transition. Twenty-two ½ Holstein-Zebu dairy steers with an average initial body weight of 234 ± 16 kg were distributed into a completely randomized design into two groups: protein-energy supplementation and mineral supplementation offered ad libitum. The steers receiving protein-energy supplementation showed higher (P energy supplementation had longer period in grazing and spent on average more time per period eating at the trough (P  0.05). The supply of protein-energy supplement does not change the feeding behavior, except for an increase in the time spent feeding at the trough. The intake of protein-energy supplement improved the of DM and NDF feed efficiencies in grazing cattle during the rainy to the dry season transition.

  12. An assessment of the importance of subsurface catch basins for Aedes aegypti adult production during the dry season in a neighborhood of Merida, Mexico.

    Science.gov (United States)

    Manrique-Saide, Pablo; Arisqueta-Chablé, Carlos; Geded-Moreno, Eduardo; Herrera-Bojórquez, Josue; Valentín, U C; Chablé-Santos, Juan; Che-Mendoza, Azael; Sánchez, Ernesto C; Arredondo-Jiménez, Juan I; Medina-Barreiro, Anuar

    2013-06-01

    We compared the number of adult Aedes aegypti emerging from subsurface catch basins located in the streets against the number of pupae (as a proxy of adults emerging) from the entire container larval habitats found at residential premises within 1 ha of a neighborhood in the Mexican city of Merida during 8 days in the dry season of 2012. Aedes aegypti adults were collected from 60% of the subsurface catch basins. They produced 12 adults/day/ha (95% confidence interval [CI], 6.4 to 17.9), 5 females (95% CI, 2.1 to 7.7), and 7 males (95% CI, 3.8 to 10.7). In contrast, only 7 containers holding water were identified in 30 premises inspected, 1 bucket was positive for Ae. aegypti larvae, but no pupae-positive containers were found. No other mosquito species were found. This study revealed the importance of this type of nonresidential and subterranean aquatic habitat for Ae. aegypti adult production in this neighborhood of Merida during the dry season.

  13. Wind energy as an alternative source to alleviate the shortage of electricity that prevails during the dry season: a case study of Tanzania

    Energy Technology Data Exchange (ETDEWEB)

    Kainkwa, R.R. [Dar es Salaam Univ., Physics Dept., Dar es Salaam (Tanzania)

    1999-10-01

    Currently, hydroelectric power supply systems in Tanzania are faced with drought, site and water management problems hindering efficient and reliable power supply from this source. Thermal power systems that were intended to alleviate the shortage of hydroelectricity that arise during the dry season are themselves expensive due to high operational and running costs as a result of the increasing prices of petroleum and spare parts. Wind speed data from two prospective sites indicate that during the dry season, wind speed is sufficiently high and steady to generate electricity. The wind speed at these sites from August to October is well above 7.0 m/s as measured at a height of 10 m above ground level. A combined hydro-generator and wind-turbine system is suggested as a possible alternative to electric power supply in Tanzania. The use of wind energy in generating electricity will reduce the large dependence on fossil fuel sources that are expensive and also harmful to our environment. (Author)

  14. Study on Photosynthesis Characters of Tamarindus indica L.in Dry Season in Yuanmou Dry-hot Valley%元谋干热河谷罗望子旱季光合特性研究

    Institute of Scientific and Technical Information of China (English)

    潘志贤; 杨艳鲜; 方海东; 彭辉; 岳学文; 钱坤建; 纪中华

    2011-01-01

    ln order to analyze the photosynthesis characters of Tamarindus indica L . in dry-hot valley, The Pn, Gs and other indexea were studied in the dry season in Yuanmou county. The results ahowed that the diumal course of Pn presented a single peak cutve and did not showed the midday depression of photoaynthesis. There was a positive correlation between Pn and PAR , the same correlation between pn , Tr, Gs and VPD. There was a negative correlation between Pn and RH. Pn was more affected by PAR than other factors. In sum the Tamarind was stmngly adapted to planting in dry-hot valley.%通过对罗望子的光合速率、气孔导度及其相应环境因子的测定,探讨元谋干热河谷罗望子旱季的光合生理生态特征.结果表明,罗望子旱季的光合速率Pn日变化曲线呈单蜂型,无光合"午休"现象发生.Pn与PAR、Tr呈极显著正相关,与RH呈极显著负相关.对Pn影响最大的因子PAR,其次是RH、Tr、Gs、VPD.罗望子在元谋干热河谷有较强的适应性.

  15. Spatial and seasonal variations of atmospheric sulfur concentrations and dry deposition at 16 rural and suburban sites in China

    Science.gov (United States)

    Luo, Xiaosheng; Pan, Yuepeng; Goulding, Keith; Zhang, Lin; Liu, Xuejun; Zhang, Fusuo

    2016-12-01

    The large emissions of sulfur dioxide (SO2) in China have raised worldwide concerns due to its contribution to acid rain and particulate pollution. Monitoring sulfur (S) concentrations and estimating its deposition are important for evaluating air quality and its effects on ecosystems and human health. To date atmospheric dry S deposition in China remains unclear due to the paucity of measurements, especially in rural regions where the ecosystems are sensitive to acid deposition. In this study, we monitored both SO2 and particulate SO42- (pSO42-) concentrations at 8 sites south and 8 sites north of the Huai River in rural and suburban parts of China between 2010 and 2012. The measured concentration of SO2 and pSO42- were combined with GEOS-Chem modeled dry deposition velocities to estimate dry S deposition inputs to the surfaces. SO2 and pSO42- concentrations were high from October/November to next March/April and they (esp. SO2) decreased sharply since March/April at the northern sites, reflecting elevated SO2 emissions by winter heating (which normally starts in October/November and ends in March/April in the north of the Huai River). However the southern sites did not show this trend. Annual dry deposition of SO2 plus pSO42- in this study ranged from 3.1 to 27.1 kg S ha-1 across all the sites in the year 2011 (except one site from May 2011 to April 2012) and showed large spatial variation. The sites in northern China had greater dry deposition due to the higher S concentrations compared with sites in southern China. We also found relatively low pSO42-/pNO3- ratios at most sites, reflecting NOx emissions had a larger influence than SO2 emissions on particle composition during the 2010-2012 period at the measurement sites. Our results suggest that dry S deposition is still important input to ecosystems in spite of slow reduction of Chinese national SO2 emissions since 2005. More research on both wet and dry S deposition and their impacts on the environment and

  16. [Chemicohydrographic characteristics and the seasonal variations of nutrients at 35 degrees N transect in the cold water mass of the Southern Yellow Sea].

    Science.gov (United States)

    Wei, Qin-Sheng; Fu, Ming-Zhu; Ge, Ren-Feng; Zang, Jia-Ye

    2010-09-01

    Based on the four cruises during 2006-2007, the chemicohydrographic characteristics and the seasonal variations of nutrients at 35 degrees N transect in the cold water mass of the Southern Yellow Sea were analyzed. The results showed that: In Winter, hydrological conditions in the eastern part of the section was significantly influenced by the Yellow Sea Warm Current, and the vertical mixing in the deep water had not reached the bottom, which led to the different distribution of the elements in the eastern and western part of the section, the vertically uniform distribution was presented in the west and the upper water of the east, while the stratification structure was found in the bottom water of the east. In Spring, the Yellow Sea warm current residual water and the Qingdao cold water mass were the most obviously hydrological characteristics, and because of the increasing of the temperature in the upper water and the weakening of the vertical mixing, the stability of the water column increased gradually; compared with winter, the contour trend of DO, pH and nutrients in deep water transferred to the more horizontal direction, and with the arrival of spring blooming, the nutrient concentrations in the upper water decreased significantly, besides, the subsurface chlorophyll maximum (SCM) phenomena also began to emerge. In Summer, the section was influenced by the thermocline and the Yellow Sea cold water mass, which was accompanied with the maximum value phenomenon of DO and pH, in addition, the nutrient concentrations were low in upper water and high in bottom water, and compared with spring, the further reduction of the nutrient concentrations existed in upper water, but the nutrient concentrations were increasing dominantly in the water below the thermocline. In Autumn, with the decreasing of the temperature in the upper water and the enhancing of the vertical mixing, the stability of the water column decreased, but the vertical mixing in the deep water was

  17. Factors Affecting Seasonal Walkability in a Cold Climate Community: A Case Study of East Lansing, Michigan, in Collaboration with Michigan State University

    Directory of Open Access Journals (Sweden)

    Joanne M. WESTPHAL

    2012-12-01

    Full Text Available At its most basic level, community involvement has as its primary goal the betterment of the community. In this study, we investigated how community involvement (a form of social capital interrelates with seasonal walkability, cycling, and running in a cold climate community like East Lansing, Michigan. A head of household survey (of 505 individuals in three different neighborhoods was conducted that asked residents about their weekly exercise patterns, and their personal service involvement with others in their neighborhoods. Poor walkability in a community is thought to be an important limiting factor to human health and a contributing factor to obesity due to an increased dependency on the automobile. Previous studies show strong correlations between physical characteristics of the built environment and the incidence of obesity in a community. In this study, we integrated dimensions of seasonal weather phenomena, socio-demographic characteristics of neighborhoods (including current levels of physical activity, and expressions of social capital into a social-environmental model of the built environment and human health. Results of this communityuniversity partnership suggest ways to enhance the city’s ability to mobilize community resources, and prioritize its own resources, in creating a more pedestrian- and cyclist-friendly environment for its citizens. It also provides insight into how, when and why citizens engage in community life, and what public officials can do to improve long-term citizen involvement in issues affecting health and quality of life in East Lansing, Michigan, USA.

  18. Comparing the Dry Season In-Situ Leaf Area Index (LAI Derived from High-Resolution RapidEye Imagery with MODIS LAI in a Namibian Savanna

    Directory of Open Access Journals (Sweden)

    Manuel J. Mayr

    2015-04-01

    Full Text Available The Leaf Area Index (LAI is one of the most frequently applied measures to characterize vegetation and its dynamics and functions with remote sensing. Satellite missions, such as NASA’s Moderate Resolution Imaging Spectroradiometer (MODIS operationally produce global datasets of LAI. Due to their role as an input to large-scale modeling activities, evaluation and verification of such datasets are of high importance. In this context, savannas appear to be underrepresented with regards to their heterogeneous appearance (e.g., tree/grass-ratio, seasonality. Here, we aim to examine the LAI in a heterogeneous savanna ecosystem located in Namibia’s Owamboland during the dry season. Ground measurements of LAI are used to derive a high-resolution LAI model with RapidEye satellite data. This model is related to the corresponding MODIS LAI/FPAR (Fraction of Absorbed Photosynthetically Active Radiation scene (MOD15A2 in order to evaluate its performance at the intended annual minimum during the dry season. Based on a field survey we first assessed vegetation patterns from species composition and elevation for 109 sites. Secondly, we measured in situ LAI to quantitatively estimate the available vegetation (mean = 0.28. Green LAI samples were then empirically modeled (LAImodel with high resolution RapidEye imagery derived Difference Vegetation Index (DVI using a linear regression (R2 = 0.71. As indicated by several measures of model performance, the comparison with MOD15A2 revealed moderate consistency mostly due to overestimation by the aggregated LAImodel. Model constraints aside, this study may point to important issues for MOD15A2 in savannas concerning the underlying MODIS Land Cover product (MCD12Q1 and a potential adjustment by means of the MODIS Burned Area product (MCD45A1.

  19. Egg Hatching and Survival of Immature Stages of Aedes aegypti (Diptera: Culicidae) Under Natural Temperature Conditions During the Cold Season in Buenos Aires, Argentina.

    Science.gov (United States)

    De Majo, María Sol; Montini, Pedro; Fischer, Sylvia

    2017-01-01

    In temperate regions, the seasonal dynamics of Aedes aegypti (L.) (Diptera: Culicidae) is mainly influenced by temperature. It is assumed that, during the winter season, the population remains as eggs and that the development and population growth of surviving eggs begin during the following spring. The aim of the current study was to assess egg hatching of Ae. aegypti during the winter in Buenos Aires city (Argentina), and analyze the survival of immature stages. The experiments consisted of immersing eggs and studying the development of immature stages of cohorts from June and September under natural temperature conditions. The proportion of hatched eggs was compared between weeks of immersion and related to environmental variables. Survival was compared among cohorts and the development rate was related to the mean temperature during development. The results showed that, with few exceptions, egg hatching was over 45% during the winter period. The proportion of hatched eggs was positively associated with immersion temperature, pre-immersion temperature and photoperiod. The immature stages completed the development during the cold season, with a trend toward increased survival of late-hatching cohorts. Survival was 30% at 13.2 °C and above 90% at 20 °C, whereas the development time at low temperatures was 49.4 d at 13.2 °C and 17.7 d at 20 °C. The high hatching and survival compared with other studies suggest that the local population might be adapting to winter conditions. The anticipated emergence of adults would be adaptive if they are able to reproduce successfully in the early spring.

  20. Variable role of aquatic macroinvertebrates in initial breakdown of seasonal leaf litter inputs to a cold-desert river

    Science.gov (United States)

    Nelson, S.M.; Andersen, D.C.

    2007-01-01

    We used coarse-mesh and fine-mesh leafpacks to examine the importance of aquatic macroinvertebrates in the breakdown of floodplain tree leaf litter that seasonally entered a sand-bedded reach of the sixth-order Yampa River in semiarid Colorado. Leafpacks were positioned off the easily mobilized channel bed, mimicking litter trapped in debris piles. Organic matter (OM) loss was fastest for leaves collected from the floodplain and placed in the river in spring (k = 0.029/day) and slowest for leaves collected and placed in the river in winter (0.006/day). Macroinvertebrates were most abundant in winter and spring leaves, but seemed important to processing only in spring, when exclusion by fine mesh reduced OM loss by 25% and nitrogen loss by 65% in spring leaves. Macroinvertebrates seemed to have little role in processing of autumn, winter, or summer leaves over the 50-day to 104-day monitoring periods. Desiccation during bouts of low discharge and sediment deposition on leaves limited invertebrate processing in summer and autumn, whereas processing of winter leaves, which supported relatively large numbers of shredders, might have been restricted by ice formation and low water temperatures. These results were consistent with the concept that microbial processing dominates in higher-order rivers, but suggested that macroinvertebrate processing can be locally important in higher-order desert rivers in seasons or years with favorable discharge and water quality conditions.

  1. Short-term effects of early-season fire on herbaceous composition, dry matter production and soil fertility in Guinea savanna, Nigeria

    Directory of Open Access Journals (Sweden)

    Oyedeji Stephen

    2016-01-01

    Full Text Available The ecological impact of fire regimes on plant diversity and soil fertility has become a subject of intense discussion, especially in savannas where recurring incidences are common. This study assessed the short-term effects of early-season fire on herbaceous composition, dry matter yield and soil fertility in the Guinea savanna belt of Nigeria. Data on ground cover, dry matter yield (DMY in plants and concentrations of C, N, P, K, Ca and Mg in soil were collected from 10 delineated subplots in the burned and unburned zones of four sites after annual wildfire had occurred. Ground cover was significantly higher in the burned zones, increasing progressively from January to April (dry season. Eleven herbaceous species in addition to 2 tree seedlings occurred and represented families of Asteraceae, Cyperaceae, Fabaceae and Poaceae. Digitaria nuda, Brachiaria lata, Daniellia oliveri and Aeschynomene indica were limited to the burnt zones while Cyperus tuberosus, Mariscus alternifolius and Rottboellia cochinchinensis were restricted to the unburned zones. DMY ranged from 0.32 g m-2 (Desmodium tortuosum to 52.96 g m-2 (Megathyrsus maximus. Average biomass in the burned and unburned sites was 35.86 g m-2 and 28.42 g m-2, respectively. Soil C, N and P concentrations decreased (positive deterioration index - DI, while those of K, Ca and Mg improved (negative DI in the burned sites. Burning altered the growth (ground cover and composition of plant species in the short term, and could significantly influence soil nutrient dynamics in the long term, especially with recurring fire events.

  2. Cistus ladanifer L. Shrub is Rich in Saturated and Branched Chain Fatty Acids and their Concentration Increases in the Mediterranean Dry Season.

    Science.gov (United States)

    Guerreiro, Olinda; Alves, Susana P; Duarte, Maria F; Bessa, Rui J B; Jerónimo, Eliana

    2015-05-01

    The Cistus ladanifer L. shrub is a widespread species of the Mediterranean region that is available as a feed source for ruminants all the year round, constituting a source of energy and nutrients when most of the vegetation is dry. However, there is no trustworthy information about the fatty acid composition of C. ladanifer, as well as no information about the seasonal and age related changes in their fatty acid composition. Thus, we collected the aerial parts of C. ladanifer plants of two age groups [young vs. older ones (2-6 years old)] during four consecutive seasons to characterize their fatty acid composition. The fatty acid composition of C. ladanifer is dominated by saturated fatty acids including the occurrence of two methyl branched chain fatty acids (BCFA), the iso-19:0 and iso-21:0, which as far as we know were detected for the first time in shrubs. Also, we demonstrated that several labdane type compounds might interfere with the fatty acid analysis of C. ladanifer. Marked seasonal changes in BCFA and polyunsaturated fatty acids (PUFA) were found, suggesting that BCFA can replace PUFA in plant lipids at high environmental temperatures.

  3. Dynamics of organochlorine contaminants in surface water and in Myriophyllum aquaticum plants of the River Xanaes in central Argentina during the annual dry season.

    Science.gov (United States)

    Schreiber, René; Harguinteguy, Carlos A; Manetti, Martin D

    2013-10-01

    The dynamics of organochlorine pesticides (OCPs) and their major metabolites were studied in surface waters and plants of the River Xanaes (province of Córdoba, Argentina) during the annual dry season. The results of the 5-month monitoring study (April to August 2010) showed similar low contamination levels in nonagricultural mountain and agricultural areas in both water and plants. The concentrations of compounds detected in the surface water were plants were dry weight) with the exception of trans-permethrin (17.6 μg kg(-1), dry weight). Because no notable differences in the contamination level between samples from the mountain and the agricultural area were observed, it was assumed that OCPs may not play an important role in today's pesticide use in this area. Furthermore, the concentration-time trends for OCPs in the submerged plants showed a generally similar elimination behaviour independent of compound and sampling site, thus indicating an integral rather then a substance-specific process, such as partitioning between the plant and the ambient water. As known, rooted macrophytes can take up contaminants by way of roots, so sediments may be the principal source. To understand the dynamics of these compounds in the river area more deeply, thus further research should include study of the river sediment.

  4. When the going gets tough: behavioural type-dependent space use in the sleepy lizard changes as the season dries.

    Science.gov (United States)

    Spiegel, Orr; Leu, Stephan T; Sih, Andrew; Godfrey, Stephanie S; Bull, C Michael

    2015-11-22

    Understanding space use remains a major challenge for animal ecology, with implications for species interactions, disease spread, and conservation. Behavioural type (BT) may shape the space use of individuals within animal populations. Bolder or more aggressive individuals tend to be more exploratory and disperse further. Yet, to date we have limited knowledge on how space use other than dispersal depends on BT. To address this question we studied BT-dependent space-use patterns of sleepy lizards (Tiliqua rugosa) in southern Australia. We combined high-resolution global positioning system (GPS) tracking of 72 free-ranging lizards with repeated behavioural assays, and with a survey of the spatial distributions of their food and refuge resources. Bayesian generalized linear mixed models (GLMM) showed that lizards responded to the spatial distribution of resources at the neighbourhood scale and to the intensity of space use by other conspecifics (showing apparent conspecific avoidance). BT (especially aggressiveness) affected space use by lizards and their response to ecological and social factors, in a seasonally dependent manner. Many of these effects and interactions were stronger later in the season when food became scarce and environmental conditions got tougher. For example, refuge and food availability became more important later in the season and unaggressive lizards were more responsive to these predictors. These findings highlight a commonly overlooked source of heterogeneity in animal space use and improve our mechanistic understanding of processes leading to behaviourally driven disease dynamics and social structure.

  5. Effects of seasonal acclimation on cold tolerance and biochemical status of the carob moth, Ectomyelois ceratoniae Zeller, last instar larvae.

    Science.gov (United States)

    Heydari, M; Izadi, H

    2014-10-01

    The carob moth, Ectomyelois ceratoniae, a pest of Punica granatum, overwinters as a larva. In this study, physiological changes, water content, cold hardiness and supercooling points (SCPs) in relation to ambient temperature in the overwintering period (October to March) and changes of these factors between diapausing (February) and non-diapausing (September) larvae were studied. Pupae that were derived from diapausing larvae (April) and from non-diapausing larvae (August) were also compared. Total body sugar, lipid and protein contents increased with decrease in the temperature and reached the highest levels (12.82, 1.99 and 6.11 mg g-1 body weight, respectively) in February, but glycogen content decreased and reached the lowest level (1.12 mg g-1 body weight) in February. There were significant differences in the levels of these compounds between diapausing and non-diapausing larvae, and pupae that were derived from diapausing and non-diapausing larvae. Trehalose and myo-inositol contents increased during diapause and reached the highest levels (0.50 and 0.07 mg g-1 body weight, respectively) in February. There were significant differences in the levels of these compounds between diapausing and non-diapausing larvae, but the differences between pupae that were derived from diapausing and non-diapausing larvae were not significant. The SCP of diapausing larvae (-17.3 °C) was significantly lower than in the non-diapausing larvae (-12.0 °C). SCP decreased gradually in autumn and reached the lowest level in the middle of winter. Changes of cold hardiness were inversely proportional to SCP changes. The lowest levels of water (65%) and weight (43.13 mg) were recorded in January and March, respectively. Most probably, lipids play a role as energy reserve, and low-molecular weight carbohydrates and polyols provide cryoprotection for overwintering larvae of the carob moth. Since the overwintering larvae die at temperatures above the SCP, the carob moth larvae were found

  6. Establishing Bedding Requirements during Transport and Monitoring Skin Temperature during Cold and Mild Seasons after Transport for Finishing Pigs

    Directory of Open Access Journals (Sweden)

    John McGlone

    2014-05-01

    Full Text Available The broad aim of this study was to determine whether bedding level in the transport trailer influenced pig performance and welfare. Specifically, the objective was to define the bedding requirements of pigs during transportation in commercial settings during cold and mild weather. Animals (n = 112,078 pigs on 572 trailers used were raised in commercial finishing sites and transported in trailers to commercial processing plants. Dead on arrival (DOA, non-ambulatory (NA, and total dead and down (D&D data were collected and skin surface temperatures of the pigs were measured by infrared thermography. Data were collected during winter (Experiment 1 and fall/spring (Experiment 2. Total D&D percent showed no interaction between bedding level and outside air temperature in any experiments. Average skin surface temperature during unloading increased with outside air temperature linearly in both experiments (P < 0.01. In conclusion, over-use of bedding may be economically inefficient. Pig skin surface temperature could be a useful measure of pig welfare during or after transport.

  7. Synchrony, compensatory dynamics, and the functional trait basis of phenological diversity in a tropical dry forest tree community: effects of rainfall seasonality

    Science.gov (United States)

    Lasky, Jesse R.; Uriarte, María; Muscarella, Robert

    2016-11-01

    Interspecific variation in phenology is a key axis of functional diversity, potentially mediating how communities respond to climate change. The diverse drivers of phenology act across multiple temporal scales. For example, abiotic constraints favor synchronous reproduction (positive covariance among species), while biotic interactions can favor synchrony or compensatory dynamics (negative covariance). We used wavelet analyses to examine phenology of community flower and seed production for 45 tree species across multiple temporal scales in a tropical dry forest in Puerto Rico with marked rainfall seasonality. We asked three questions: (1) do species exhibit synchronous or compensatory temporal dynamics in reproduction, (2) do interspecific differences in phenology reflect variable responses to rainfall, and (3) is interspecific variation in phenology and response to a major drought associated with functional traits that mediate responses to moisture? Community-level flowering was synchronized at seasonal scales (˜5-6 mo) and at short scales (˜1 mo, following rainfall). However, seed rain exhibited significant compensatory dynamics at intraseasonal scales (˜3 mo), suggesting interspecific variation in temporal niches. Species with large leaves (associated with sensitivity to water deficit) peaked in reproduction synchronously with the peak of seasonal rainfall (˜5 mo scale). By contrast, species with high wood specific gravity (associated with drought resistance) tended to flower in drier periods. Flowering of tall species and those with large leaves was most tightly linked to intraseasonal (˜2 mo scale) rainfall fluctuations. Although the 2015 drought dramatically reduced community-wide reproduction, functional traits were not associated with the magnitude of species-specific declines. Our results suggest opposing drivers of synchronous versus compensatory dynamics at different temporal scales. Phenology associations with functional traits indicated that

  8. Non-stationary analysis of dry spells in monsoon season of Senegal River Basin using data from Regional Climate Models (RCMs)

    Science.gov (United States)

    Giraldo Osorio, J. D.; García Galiano, S. G.

    2012-07-01

    SummaryThe Senegal River Basin, located in West Africa, has been affected by several droughts since the end of the 1960s. In its valley, which is densely populated and highly vulnerable to climate variability and water availability, agricultural activities provide the livelihood for thousands of people. Increasing the knowledge about plausible trends of drought events will allow to improve the adaptation and mitigation measures in order to build "adaptive capacity" to climate change in West Africa. An innovative methodology for the non-stationary analysis of droughts events, which allows the prediction of regional trends associated to several return periods, is presented. The analyses were based on Regional Climate Models (RCMs) provided by the European ENSEMBLES project for West Africa, together with observed data. A non-stationary behaviour of the annual series of maximum length of dry spells (AMDSL) in the monsoon season is reflected in temporal changes in mean and variance. The non-stationary nature of hydrometeorological series, due to climate change and anthropogenic activities, is the main criticism to traditional frequency analysis. Therefore, in this paper, the modelling tool GAMLSS (Generalized Additive Models for Location, Scale and Shape), is applied to develop regional probability density functions (pdfs) fitted to AMDSL series for the monsoon season in the Senegal River Basin. The skills of RCMs in the representation of maximum length of dry spells observed for the period 1970-1990, are evaluated considering observed data. Based on the results obtained, a first selection of the RCMs with which to apply GAMLSS to the AMDSL series identified, for the time period 1970-2050, is made. The results of GAMLSS analysis exhibit divergent trends, with different value ranges for parameters of probability distributions being detected. Therefore, in the second stage of the paper, regional pdfs are constructed using bootstrapping distributions based on probabilistic

  9. A study on the predictability of the transition day from the dry to the rainy season over South Korea

    Science.gov (United States)

    Lee, Sang-Min; Nam, Ji-Eun; Choi, Hee-Wook; Ha, Jong-Chul; Lee, Yong Hee; Kim, Yeon-Hee; Kang, Hyun-Suk; Cho, ChunHo

    2016-08-01

    This study was conducted to evaluate the prediction accuracies of THe Observing system Research and Predictability EXperiment (THORPEX) Interactive Grand Global Ensemble (TIGGE) data at six operational forecast centers using the root-mean square difference (RMSD) and Brier score (BS) from April to July 2012. And it was performed to test the precipitation predictability of ensemble prediction systems (EPS) on the onset of the summer rainy season, the day of withdrawal in spring drought over South Korea on 29 June 2012 with use of the ensemble mean precipitation, ensemble probability precipitation, 10-day lag ensemble forecasts (ensemble mean and probability precipitation), and effective drought index (EDI). The RMSD analysis of atmospheric variables (geopotential-height at 500 hPa, temperature at 850 hPa, sea-level pressure and specific humidity at 850 hPa) showed that the prediction accuracies of the EPS at the Meteorological Service of Canada (CMC) and China Meteorological Administration (CMA) were poor and those at the European Center for Medium-Range Weather Forecasts (ECMWF) and Korea Meteorological Administration (KMA) were good. Also, ECMWF and KMA showed better results than other EPSs for predicting precipitation in the BS distributions. It is also evaluated that the onset of the summer rainy season could be predicted using ensemble-mean precipitation from 4-day leading time at all forecast centers. In addition, the spatial distributions of predicted precipitation of the EPS at KMA and the Met Office of the United Kingdom (UKMO) were similar to those of observed precipitation; thus, the predictability showed good performance. The precipitation probability forecasts of EPS at CMA, the National Centers for Environmental Prediction (NCEP), and UKMO (ECMWF and KMA) at 1-day lead time produced over-forecasting (under-forecasting) in the reliability diagram. And all the ones at 2˜4-day lead time showed under-forecasting. Also, the precipitation on onset day of

  10. 辣鲜露调味料的工艺研究%Study on the Process of Spicy Fresh Dew Seasoning with Dried Chili

    Institute of Scientific and Technical Information of China (English)

    陶德才

    2014-01-01

    Spicy fresh dew seasoning is a new spicy and fresh complex seasoning,the complex taste and spicy flavor of various dishes can be improved efficiently through extracting spicy ingredients and spicy substances from dried chili and natural spices.Spicy and fresh taste is reconciled uniformly,highly concentrated;either for pre-marinated or post-frying,it can enhance the overall flavor.In this study, using water as solvent to prepare spicy sauce by extracting the spicy ingredients from dried chili and natural spices,then add capsicum oleoresin,yeast extract,sodium glutamate,xanthan gum,salt, I+G,white sugar and other accessories,optimize the formula process of spicy fresh dew seasoning through single factor and orthogonal experiments,develop the seasoning product with unique spicy and fresh flavor,enticing aroma fragrance and stable quality.%辣鲜露调味料是一种新型的辣鲜复合调味料,通过萃取干辣椒和天然香辛料中的辣味成分和辛辣物质,能有效提高各式菜肴的复合口感和鲜辣风味。辣与鲜的口感调和均匀,高度浓缩,无论是对菜肴前期腌制或是后期烹炒,都能起到鲜香并重、提升整体风味的效果。研究以水为溶剂,通过萃取干辣椒和天然香辛料中辛辣风味成分制备成辛辣汁,再添加辣椒油树脂、酵母抽提物、谷氨酸钠、黄原胶、食用盐、I+G、白砂糖等辅料,通过单因素实验和正交实验对辣鲜露调味料的配方工艺进行优化,研制出辣鲜风味独特、香气馥郁诱人、质量稳定的调味产品。

  11. Response of aboveground carbon balance to long-term, experimental enhancements in precipitation seasonality is contingent on plant community type in cold-desert rangelands

    Science.gov (United States)

    McAbee, Kathryn; Reinhardt, Keith; Germino, Matthew; Bosworth, Andrew

    2017-01-01

    Semi-arid rangelands are important carbon (C) pools at global scales. However, the degree of net C storage or release in water-limited systems is a function of precipitation amount and timing, as well as plant community composition. In northern latitudes of western North America, C storage in cold-desert ecosystems could increase with boosts in wintertime precipitation, in which climate models predict, due to increases in wintertime soil water storage that enhance summertime productivity. However, there are few long-term, manipulative field-based studies investigating how rangelands will respond to altered precipitation amount or timing. We measured aboveground C pools and fluxes at leaf, soil, and ecosystem scales over a single growing season in plots that had 200 mm of supplemental precipitation added in either winter or summer for the past 21 years, in shrub- and exotic-bunchgrass-dominated garden plots. At our cold-desert site (298 mm precipitation during the study year), we hypothesized that increased winter precipitation would stimulate the aboveground C uptake and storage relative to ambient conditions, especially in plots containing shrubs. Our hypotheses were generally supported: ecosystem C uptake and long-term biomass accumulation were greater in winter- and summer-irrigated plots compared to control plots in both vegetation communities. However, substantial increases in the aboveground biomass occurred only in winter-irrigated plots that contained shrubs. Our findings suggest that increases in winter precipitation will enhance C storage of this widespread ecosystem, and moreso in shrub- compared to grass-dominated communities.

  12. Seasonal Variation of Polyciclic Aromatic Hydrocarbons in the Atmosphere of Mexico City

    Science.gov (United States)

    Mugica, V.; Hernandez, S.; Torres, M.; García, R.

    2007-05-01

    With the aim to determine concentrations levels and seasonal variation of polyaromatic hydrocarbons (PAH) in the northern of Mexico City, three sampling campaigns were performed during cold dry season, rain season and hot dry season in 2005. Particle-bound polycyclic aromatic hydrocarbons were collected on quartz fiber filters and gas-phase PAH was collected into polyurethane foam (PUF) with XAD-4 resin. Both types of samples were extracted with a dichloromethane and acetonitrile (2:1). Quantification of 17 PAH was carried out using gas chromatography .mass spectrometry (GC-MS). Recovery factors were determined by spiking filters with standard (NIST SRM 1647c). Average PM10 concentrations during the three seasons were 62.3, 68.9 and 131 μ gm- 3 for hot dry season, rainy season and hot dry season respectively. In the hot dry season the total of quantified PAH in particles was in average 1.99±0.82 ngm-3 and the dominant PAH compounds were Pyr, BghiP and Cry; the rainy season presented a total of 2.8± 1.2 ngm-3 of quantified PAH in particles and the pore abundant PAH were BaA, BbF, and BghiP; the cold dry season presented the highest concentrations with an average of quantified PAH in particles of 15.5± 4.9 ng-3 and BbF, BaA, and BghiP were the most abundant compounds. The most abundant PAH in the gaseous phase in the three seasons were naphtalene, pyrene and acenaphtylene with average concentrations of 132, 2.7 and 2.1 ngm-3 in the hot dry season, 18.1, 0.47 and 1.8 ngm-3 in the rainy season and 58, 1.71 and 2.37 ngm-3 in the cold dry season. Principal component analyses and cluster analyses were applied to relate the PAH concentrations with their sources.

  13. Variations in soil properties, species composition, diversity and biomass of herbaceous species due to ruminant dung residue in a seasonally dry tropical environment of India

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    Preeti Verma

    2015-05-01

    Full Text Available Ruminants directly or indirectly influence nutrient cycling and vegetation structure in grassland ecosystems. We assessed the impact of natural cattle dung deposition on soil attributes and the resulting effects on species composition, species diversity and biomass of herbaceous vegetation in a natural grassland in the seasonally dry tropical environment of Banaras Hindu University, India. For this 72 plots of 1 × 1 m [12 locations × 2 treatments (dung residue and control × 3 replicates] were selected in January 2013 and soil and vegetation samples collected. A total of 74 species belonging to 66 genera and 25 families were recorded. Principal Component Analysis (PCA ordination revealed that the dung residue (DP and control (CP plots were distinctly different in terms of soil attributes and species composition. The k-dominance plot showed greater species diversity in DPs than CPs, with higher soil nutrients and moisture and lower soil pH in DPs than CPs. Similarly, DPs showed more herbaceous species and greater biomass than CPs. This trend can be explained by the positive responses of forbs, erect plants, annuals, large-statured, non-native and non-leguminous species to dung residue, while increased biomass can be partly due to cattle preferentially not grazing areas adjacent to a dung pat. Overall, the study showed that deposition of dung during grazing by cattle stimulates growth of pasture species and increases species diversity. Therefore cattle dung could be used as a sustainable alternative to chemical fertilizers to manage soil pH, species composition and diversity, and forage production in the seasonally dry tropical grasslands of India, which are nutrient- and moisture-limited.Keywords: Animal manure, herbaceous vegetation, plant functional attributes, soil pH, species change.DOI: 10.17138/TGFT(3112-128 

  14. Assessment of dry season garden egg production among small-scale farmers in Edu Local Government Area of Kwara State, Nigeria

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    Omotesho Olubunmi Abayomi

    2017-01-01

    Full Text Available The study was carried out for the purpose of assessing dry season garden egg production among small-scale farmers in Edu Local Government Area of Kwara State. The study adopted a snowballing sampling technique to sample 120 small-scale garden egg farmers. Five research questions were formulated to achieve the objectives of this research work. Descriptive statistics, cost and return analysis and OLS regression were used to analyze data collected. Cost and return analysis shows that the total revenue generated from the sales of irrigated garden egg produce for a typical farmer was N 36,596.5k while the total fixed cost (depreciated and variable input cost amounted to 1,279.22K to give a net farm income (NFI of N 24,582.68k. The OLS regression results revealed that the coefficients of farm size and household size were positive and significant at the 1% and 10% levels of probability respectively. This implies that an increase in farm size by 1 ha will increase the production of dry season garden egg by 1 percent. While the results of stochastic production frontier estimate show that the parameters of labour, fertilizer and farm size were highly significant, chemical use was significant at 10% level. This result implies that the farmers were technically efficient in the use of labour, fertilizer, chemical and farm size. Therefore, it is recommended that farmers should be encouraged to form cooperative societies, whereby they can join their resources together to provide a cost-effective irrigation system. Also, government authorities and other non-governmental organizations are encouraged to give farmers fertilizers and other chemicals at subsidized rates. There is a need for revitalization of the marketing board in Nigeria to further strengthen the marketing of agricultural produce and reduce marketing, storage and transportation problems.

  15. [Nitrogen Release from Sediment Under Dry and Rainy Season Alternation and Its Contribution to N Export from Xiangxi Watershed in Jiangxi Province].

    Science.gov (United States)

    Han, Ning; Hao, Zhuo; Xu, Ya-juan; Gao, Yang; Yu, Gui-rui

    2016-02-15

    In this study, N export from Xiangxi River Basin in Qianyanzhou station was measured by long-term monitoring, and simulation study on N. release law from the sediment in watershed was carried out based on orthogonal experiment, and at last the contributions of N release from sediment to N transport from watershed under dry and rainy season alternation were estimated. The results showed that the maximum of TN release rate was 36 mg x (m2 x d)(-1) in stable status, which decreased with increasing time; the impact of the three controlling factors on the N release followed the order of temperature > disturbance > pH, and the effect of temperature and pH on N release from the sediment was significant when disturbance was considered as the error term; TN release rate increased with increase of temperature, and acidic and alkaline conditions could also promote N release from sediment, wherein the effect of acidic conditions on N release was stronger; the changes of TN and available N content in sediment were 414.7-899.6 mg x kg(-1) and 17.5-58.9 mg x kg(-1), so the percentage of available N only accounted for 3%-10% of TN; the TN transport concentrations were 0.58-2.40 mg x L(-1) and 1.73-4.87 mg x L(-1) in dry and wet seasons, respectively, the N release flux from sediment was about 106.34 kg x a(-1), the total N transport from watershed was 864.15 kg x a(-1), and the contribution rate of N release from sediment to N transport from watershed was about 12.31%, so we should pay much attention to the contribution of N release from sediment to water eutrophication.

  16. Elevated dry-season malaria prevalence associated with fine-scale spatial patterns of environmental risk: a case-control study of children in rural Malawi.

    Science.gov (United States)

    Townes, Lindsay R; Mwandama, Dyson; Mathanga, Don P; Wilson, Mark L

    2013-11-11

    Understanding the role of local environmental risk factors for malaria in holo-endemic, poverty-stricken settings will be critical to more effectively implement- interventions aimed at eventual elimination. Household-level environmental drivers of malaria risk during the dry season were investigated in rural southern Malawi among children Authority (TA) regions dominated by small-scale agriculture. Ten villages were randomly selected from TA Sitola (n = 6) and Nsamala (n = 4). Within each village, during June to August 2011, a census was conducted of all households with children under-five and recorded their locations with a geographic position system (GPS) device. At each participating house, a nurse administered a malaria rapid diagnostic test (RDT) to children under five years of age, and a questionnaire to parents. Environmental data were collected for each house, including land cover within 50-m radius. Variables found to be significantly associated with P. falciparum infection status in bivariate analysis were included in generalized linear models, including multivariate logistic regression (MLR) and multi-level multivariate logistic regression (MLLR). Spatial clustering of RDT status, environmental factors, and Pearson residuals from MLR and MLLR were analysed using the Getis-Ord Gi* statistic. Of 390 children enrolled from six villages in Sitola (n = 162) and four villages in Nsamala (n = 228), 45.6% tested positive (n = 178) for Plasmodium infection by RDT. The MLLR modelled the statistical relationship of Plasmodium positives and household proximity to agriculture ( 2.58, p < 0.01) predominantly within TA Sitola, while residuals from MLLR showed no such clustering. This study provides evidence for significant, dry-season heterogeneity of malaria prevalence strongly linked to peridomestic land use, and particularly of elevated risk associated with nearby crop production.

  17. Impact of tilling on biosolids drying and indicator microorganisms survival during solar drying process.

    Science.gov (United States)

    Song, Inhong; Dominguez, Teodulo; Choi, Christopher Y; Kang, Moon Seong

    2014-01-01

    As biosolids application to croplands becomes a common practice, potential harm from pathogenic microbes needs to be mitigated for its safe reuse. The objective of this study was to investigate the impacts of tilling treatment on biosolids drying and microbial inactivation during the solar drying process in a semi-arid and temperate region. Solar drying experiments were conducted in sand and gravel dying beds open-to-the-air and under covering structures with biosolids to 20 cm depth from 2004 to 2006. Anaerobically- and Aerobically-digested biosolids received different tilling treatments throughout the drying process, while a series of biosolids samples were collected to determine the impact on total solids and microbial concentrations (Salmonella spp and heminth ova). Tilling treatments appeared to enhance the biosolids drying and microbial inactivation. Tilling was more effective during the cold season compared with the summer season and tilling treatments were also helpful in elevating biosolids temperature by expediting biosolids drying. The combined effect of temperature increase and moisture decrease by tilling may have resulted in faster microbial inactivation, particularly for persistent helminth ova. It was concluded that incorporation of tilling into biosolids solar drying can expedite biosolids drying as well as microbial inactivation, and thus can be an effective measure for shortening the biosolids conversion to Class A biosolids in which pathogens are reduced to below detectable levels.

  18. Annual Report: 2010-2011 Storm Season Sampling For NON-DRY DOCK STORMWATER MONITORING FOR PUGET SOUND NAVAL SHIPYARD, BREMERTON, WA

    Energy Technology Data Exchange (ETDEWEB)

    Brandenberger, Jill M.; Metallo, David; Johnston, Robert K.; Gebhardt, Christine; Hsu, Larry

    2012-09-01

    This interim report summarizes the stormwater monitoring conducted for non-dry dock outfalls in both the confined industrial area and the residential areas of Naval Base Kitsap within the Puget Sound Naval Shipyard (referred to as the Shipyard). This includes the collection, analyses, and descriptive statistics for stormwater sampling conducted from November 2010 through April 2011. Seven stormwater basins within the Shipyard were sampled during at least three storm events to characterize non-dry dock stormwater discharges at selected stormwater drains located within the facility. This serves as the Phase I component of the project and Phase II is planned for the 2011-2012 storm season. These data will assist the Navy, USEPA, Ecology and other stakeholders in understanding the nature and condition of stormwater discharges from the Shipyard and inform the permitting process for new outfall discharges. The data from Phase I was compiled with current stormwater data available from the Shipyard, Sinclair/Dyes Inlet watershed, and Puget Sound in order to support technical investigations for the Draft NPDES permit. The permit would require storm event sampling at selected stormwater drains located within the Shipyard. However, the data must be considered on multiple scales to truly understand potential impairments to beneficial uses within Sinclair and Dyes Inlets.

  19. Effect of water stress on seedling growth in two species with different abundances: the importance of Stress Resistance Syndrome in seasonally dry tropical forest

    Directory of Open Access Journals (Sweden)

    Wanessa Nepomuceno Ferreira

    2015-09-01

    Full Text Available ABSTRACTIn seasonally dry tropical forests, species carrying attributes of Stress Resistance Syndrome (SRS may have ecological advantages over species demanding high quantities of resources. In such forests, Poincianella bracteosa is abundant, while Libidibia ferrea has low abundance; therefore, we hypothesized that P. bracteosa has characteristics of low-resource species, while L. ferrea has characteristics of high-resource species. To test this hypothesis, we assessed morphological and physiological traits of seedlings of these species under different water regimes (100%, 70%, 40%, and 10% field capacity over 85 days. For most of the studied variables we observed significant decreases with increasing water stress, and these reductions were greater in L. ferrea. As expected, L. ferreamaximized their growth with increased water supply, while P. bracteosa maintained slower growth and had minor adjustments in biomass allocation, characteristics representative of low-resource species that are less sensitive to stress. We observed that specific leaf area, biomass allocation to roots, and root/shoot ratio were higher in L. ferrea, while biomass allocation to leaves and photosynthesis were higher in P. bracteosa. Results suggest that the attributes of SRS can facilitate high abundance of P. bracteosa in dry forest.

  20. The Effect of Passive Design Strategies on Thermal Performance of Female Secondary School Buildings during Warm Season in Hot Dry Climate

    Directory of Open Access Journals (Sweden)

    Sahar eZahiri

    2016-03-01

    Full Text Available This paper describes a series of field studies and simulation analysis to improve the thermal performance of school buildings in the city of Tehran in Iran during warm season. The field studies used on-site measurement and questionnaire-based survey in the warm spring season in a typical female secondary school building. The on-site monitoring assessed the indoor air temperature and humidity levels of six classrooms while the occupants completed questionnaires covering their thermal sensations and thermal preferences. Moreover, thermal simulation analysis was also carried out to evaluate and improve the thermal performance of the classrooms based on the students’ thermal requirements and passive design strategies. In this study, the environmental design guidelines for female secondary school buildings were introduced for the hot and dry climate of Tehran, using passive design strategies. The study shows that the application of passive design strategies including south and south-east orientation, 10cm thermal insulation in wall and 5cm in the roof, and the combination of 30cm side fins and overhangs as a solar shading devices, as well as all-day ventilation strategy and the use of thermal mass materials with 25cm-30cm thickness, has considerable impact on indoor air temperatures in warm season in Tehran and keeps the indoor environment in an acceptable thermal condition. The results of the field studies also indicated that most of the occupants found their thermal environment not to be comfortable and the simulation results showed that passive design techniques had a significant influence on the indoor air temperature and can keep it in an acceptable range based on the female students’ thermal requirement. Therefore, in order to enhance the indoor environment and to increase the learning performance of the students, it is necessary to use the appropriate passive design strategies, which also reduce the need for mechanical systems and

  1. Coupled prediction of flood response and debris flow initiation during warm- and cold-season events in the Southern Appalachians, USA

    Science.gov (United States)

    Tao, J.; Barros, A. P.

    2014-01-01

    Debris flows associated with rainstorms are a frequent and devastating hazard in the Southern Appalachians in the United States. Whereas warm-season events are clearly associated with heavy rainfall intensity, the same cannot be said for the cold-season events. Instead, there is a relationship between large (cumulative) rainfall events independently of season, and thus hydrometeorological regime, and debris flows. This suggests that the dynamics of subsurface hydrologic processes play an important role as a trigger mechanism, specifically through soil moisture redistribution by interflow. We further hypothesize that the transient mass fluxes associated with the temporal-spatial dynamics of interflow govern the timing of shallow landslide initiation, and subsequent debris flow mobilization. The first objective of this study is to investigate this relationship. The second objective is to assess the physical basis for a regional coupled flood prediction and debris flow warning system. For this purpose, uncalibrated model simulations of well-documented debris flows in headwater catchments of the Southern Appalachians using a 3-D surface-groundwater hydrologic model coupled with slope stability models are examined in detail. Specifically, we focus on two vulnerable headwater catchments that experience frequent debris flows, the Big Creek and the Jonathan Creek in the Upper Pigeon River Basin, North Carolina, and three distinct weather systems: an extremely heavy summertime convective storm in 2011; a persistent winter storm lasting several days; and a severe winter storm in 2009. These events were selected due to the optimal availability of rainfall observations; availability of detailed field surveys of the landslides shortly after they occurred, which can be used to evaluate model predictions; and because they are representative of events that cause major economic losses in the region. The model results substantiate that interflow is a useful prognostic of conditions

  2. Identity and relationships of the Arboreal Caatinga among other floristic units of seasonally dry tropical forests (SDTFs) of north-eastern and Central Brazil.

    Science.gov (United States)

    Santos, Rubens M; Oliveira-Filho, Ary T; Eisenlohr, Pedro V; Queiroz, Luciano P; Cardoso, Domingos B O S; Rodal, Maria J N

    2012-02-01

    The tree species composition of seasonally dry tropical forests (SDTF) in north-eastern and central Brazil is analyzed to address the following hypotheses: (1) variations in species composition are related to both environment (climate and substrate) and spatial proximity; (2) SDTF floristic units may be recognized based on peculiar composition and environment; and (3) the Arboreal Caatinga, a deciduous forest occurring along the hinterland borders of the Caatinga Domain, is one of these units and its flora is more strongly related to the caatinga vegetation than to outlying forests. The study region is framed by the Brazilian coastline, 50th meridian west and 21st parallel south, including the Caatinga Domain and extensions into the Atlantic Forest and Cerrado Domains. Multivariate and geostatistic analyses were performed on a database containing 16,226 occurrence records of 1332 tree species in 187 georeferenced SDTF areas and respective environmental variables. Tree species composition varied significantly with both environmental variables and spatial proximity. Eight SDTF floristic units were recognized in the region, including the Arboreal Caatinga. In terms of species composition, its tree flora showed a stronger link with that of the Cerrado Dry Forest Enclaves. On the other hand, in terms of species frequency across sample areas, the links were stronger with two other units: Rock Outcrops Caatinga and Agreste and Brejo Dry Forests. There is a role for niche-based control of tree species composition across the SDTFs of the region determined primarily by the availability of ground water across time and secondarily by the amount of soil mineral nutrients. Spatial proximity also contributes significantly to the floristic cohesion of SDTF units suggesting a highly dispersal-limited tree flora. These units should be given the status of eco-regions to help driving the conservation policy regarding the protection of their biodiversity.

  3. Numerical Prediction of Cold Season Fog Events over Complex Terrain: the Performance of the WRF Model During MATERHORN-Fog and Early Evaluation

    Science.gov (United States)

    Pu, Zhaoxia; Chachere, Catherine N.; Hoch, Sebastian W.; Pardyjak, Eric; Gultepe, Ismail

    2016-09-01

    A field campaign to study cold season fog in complex terrain was conducted as a component of the Mountain Terrain Atmospheric Modeling and Observations (MATERHORN) Program from 07 January to 01 February 2015 in Salt Lake City and Heber City, Utah, United States. To support the field campaign, an advanced research version of the Weather Research and Forecasting (WRF) model was used to produce real-time forecasts and model evaluation. This paper summarizes the model performance and preliminary evaluation of the model against the observations. Results indicate that accurately forecasting fog is challenging for the WRF model, which produces large errors in the near-surface variables, such as relative humidity, temperature, and wind fields in the model forecasts. Specifically, compared with observations, the WRF model overpredicted fog events with extended duration in Salt Lake City because it produced higher moisture, lower wind speeds, and colder temperatures near the surface. In contrast, the WRF model missed all fog events in Heber City, as it reproduced lower moisture, higher wind speeds, and warmer temperatures against observations at the near-surface level. The inability of the model to produce proper levels of near-surface atmospheric conditions under fog conditions reflects uncertainties in model physical parameterizations, such as the surface layer, boundary layer, and microphysical schemes.

  4. Daily rhythms of cloacal temperature in broiler chickens of different age groups administered with zinc gluconate and probiotic during the hot-dry season.

    Science.gov (United States)

    Aluwong, Tagang; Sumanu, Victory O; Ayo, Joseph O; Ocheja, Benjamin O; Zakari, Friday O; Minka, Ndazo S

    2017-06-01

    The aim of the experiment was to evaluate effects of zinc gluconate (ZnGlu) and probiotic administration on the daily rhythm of cloacal temperature (tcloacal) in broiler chickens of different age groups during the hot-dry season. One-day-old broiler chicks (n = 60) were divided into groups I-IV of 15 chicks per group, and treated for 35 days: Group I (control) was given deionized water; Group II, ZnGlu (50 mg/kg); Group III, probiotic (4.125 × 10(6 )cfu/100 mL), and Group IV, ZnGlu (50 mg/kg) + probiotic (4.125 × 10(6 )cfu/100 mL). Air dry-bulb temperature (tdb), relative humidity (RH), and temperature-humidity index (THI) inside the pen, and tcloacal of each broiler chick were obtained bihourly over a 24-h period; on days 21, 28, and 35 of the study. Values of tdb (32.10 ± 0.49°C), RH (49.94 ± 1.91%), and THI (38.85 ± 0.42) obtained were outside the thermoneutral zone for broiler chickens, and suggested that the birds were subjected to heat stress. Application of the periodic model showed disruption of daily rhythm of tcloacal in broilers on day 21, which was synchronized by probiotic administration. The administration of probiotics or ZnGlu + probiotics to a greater extent decreased the mesor and amplitude, delayed the acrophases of tcloacal in broilers, especially at day 35, as compared to the controls. Overall, the tcloacal values in broiler chickens administered with probiotic alone (41.25 ± 0.05°C) and ZnGlu + probiotic (41.52 ± 0.05°C) were lower (P heat stress on broiler chickens during the hot-dry season. © 2017 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of The Physiological Society and the American Physiological Society.

  5. Suspended sediment transport in the Deepwater Navigation Channel, Yangtze River Estuary, China, in the dry season 2009: 2. Numerical simulations

    Science.gov (United States)

    Song, Dehai; Wang, Xiao Hua

    2013-10-01

    A three-dimensional wave-current-sediment coupled numerical model with wetting and drying process is developed to understand hydrodynamics and sediment transport dynamics in the Deepwater Navigation Channel (DNC), the North Passage of the Yangtze River Estuary (YRE), China. The model results are in good agreement with observed data, and statistics show good model skill scores and correlation coefficients. The model well reproduces the spring-neap variation between a well-mixed estuary and a highly stratified estuary. Model results indicate that the estuarine gravitational circulation plays the most important role in the estuarine turbidity maximum (ETM) formation in the DNC. The upstream nonlocal sediment intrusion through the spillover mechanism is a major source of sediment trapping in the North Passage after the morphological changes. Numerical studies are conducted to show scenarios in the YRE under the effects of different forcings (river discharges, waves, and winds). Between these study cases, surface-wave-breaking relieves the sediment trapping and bottom-wave-current-interaction aggravates the bed erosion and elevates the SSC in the ETM; the former and the latter have the least and largest influence on the suspended sediment transport in the DNC. The wind effects have a greater influence on sediment trapping than the river discharges, and the steady northwesterly wind condition favors the siltation in the DNC most. The significance of density-driven turbidity current is also assessed, which can enhance the saline-water intrusion and suppress the turbulent mixing in the bottom boundary layer.

  6. Biochemical responses in tree foliage exposed to coal-fired power plant emission in seasonally dry tropical environment.

    Science.gov (United States)

    Sharma, Atul Prakash; Tripathi, B D

    2009-11-01

    A biomonitoring study was conducted to investigate the responses of plants exposed to power plant emission in a dry tropical environment. For this purpose, five sampling sites were selected in the prevailing wind direction (NE) at different distance to thermal power plant (TPP) within 8.0 km range and a reference site was selected in eastern direction at a distance of 22.0 km. The two most common tree species, Ficus benghalensis L. (Evergreen tree) and Dalbergia sisso Roxb. (deciduous tree) were selected as test plants. Ambient sulphur dioxide (SO(2)), nitrogen dioxide (NO(2)), suspended particulate matter (SPM), respirable suspended particulate matter (RSPM), dust-fall rate (DFR) and plant responses such as leaf pigments (chlorophyll a, chlorophyll b and carotenoids), ascorbic acid, sugar and sulphate-sulphur (SO4(2-)-S) contents were measured. Ambient SO(2), NO(2), SPM, RSPM and DFR showed significant spatial and temporal variation at different sites. Considerable reduction in pigment (chlorophyll a, chlorophyll b and carotenoids) and sugar contents were observed at sites receiving higher pollution load. Ascorbic acid exhibited significant positive correlation with pollution load. Accumulation of SO4(2-)-S in leaf tissue showed significant positive correlation with ambient SO(2) concentration at all the sites. At the same time, SO4(2-)-S showed significant negative correlation with pigment and sugar content. D. sisso Roxb. tree was found to be more sensitive as compared to F. benghalensis L. tree.

  7. REPRODUCTIVE AND METABOLIC RESPONSES IN EWES TO DIETARY PROTEIN SUPPLEMENT DURING MATING PERIOD IN DRY SEASON OF NORTHEAST BRAZIL

    Directory of Open Access Journals (Sweden)

    Magda Rodrigues

    2015-01-01

    Full Text Available This study evaluated the effect of food supplements with different levels of protein on reproductive and metabolic response of ewes during the mating period. Forty-one ewes were supplemented during 43 days with amount protein to meet 1.0 (diet I; n = 14, 1.7 (diet II; n = 13 and 2.1 (diet III; n = 14 times the maintenance requirements. Dry matter (DM intake was higher (P < 0.01 in diet III when compared to diets I and II. Orts were lesser in diets II and III (P < 0.05 when compared to diet I. Intake of organic matter (OM, crude protein (CP and ether extract (EE was higher in diet III (P < 0.05, but NDF and ADF intake was superior in diet I (P < 0.05. In diet III, a higher frequency of female mated was observed (P < 0.05. The prolificity and twinning rate was higher in ewes of diet II (P < 0.05. Greater birth weight of lambs (P < 0.05 was verified in diet III. The progesterone levels were affected by diets II and III (P < 0.05. In conclusion, the supplementation of ewes with intermediate level of protein improves their reproductive response.

  8. [Displacements of the green iguana (Iguana iguana) (Squamata: Iguanidae) during the dry season in La Palma, Veracruz, Mexico].

    Science.gov (United States)

    Morales-Mávil, Jorge E; Vogt, Richard C; Gadsden-Esparza, Héctor

    2007-06-01

    The green iguana (Iguana iguana) is said to be primarily sedentary, although the females travel long distances to nest. Displacement patterns must be known to help predict the effects of environmental disturbance on iguanas' survival. We studied nesting season (February-July) movements in La Palma, Los Tuxtlas, Veracruz, Mexico (18 degrees 33' N, 95 degrees 03' W). Individual movements and activity were monitored by radio tracking. The transmitters were implanted surgically in eight adult iguanas (four males and four females). Snout vent length (SVL) was used to determine the relationship between size of the body and size of home range. To estimate the size of home range, three or more points were used. Minimum convex polygons estimates of home range were calculated with McPAAL. The iguanas were radio-located between 23 and 30 occasions, mainly in trees (56% between 3-9 m); only 4% were localized under a height of 3 m (forest floor). The occupation area mean was larger for males (9,158.06+/-3,025.3 m2 vs. 6,591.24+/-4,001.1 m2) although the differences were not significant (t= 0.51, p>0.05). SVL was correlated with home range (r= 0.76; gl= 7; p<0.05). Breeding males defended their home range vigorously against other adult males. We observed one separate male home range and large portions of overlap between the sexes. The home range generally formed a conglomerate of polygons and only two had linear shapes along the river: apparently iguanas use the riparian vegetation for foraging. The females display two strategies for nesting: 1) moving to the sandy area near the sea or, 2) laying eggs near the river, in loam. Iguanas responded to habitat fragmentation and reduction by modifying their nesting strategy.

  9. Seasonal, synoptic and diurnal variation of atmospheric water-isotopologues in the boundary layer of Southwestern Germany caused by plant transpiration, cold-front passages and dewfall.

    Science.gov (United States)

    Christner, Emanuel; Dyroff, Christoph; Kohler, Martin; Zahn, Andreas; Gonzales, Yenny; Schneider, Matthias

    2013-04-01

    Atmospheric water is an enormously crucial trace gas. It is responsible for ~70 % of the natural greenhouse effect (Schmidt et al., JGR, 2010) and carries huge amounts of latent heat. The isotopic composition of water vapor is an elegant tracer for a better understanding and quantification of the extremely complex and variable hydrological cycle in Earth's atmosphere (evaporation, cloud condensation, rainout, re-evaporation, snow), which in turn is a prerequisite to improve climate modeling and predictions. As H216O, H218O and HDO differ in vapor pressure and mass, isotope fractionation occurs due to condensation, evaporation and diffusion processes. In contrast to that, plants are able to transpire water with almost no isotope fractionation. For that reason the ratio of isotopologue concentrations in the boundary layer (BL) provides, compared to humidity measurements alone, independent and additional constraints for quantifying the strength of evaporation and transpiration. Furthermore the isotope ratios contain information about transport history of an air mass and microphysical processes, that is not accessible by humidity measurements. Within the project MUSICA (MUlti-platform remote Sensing of Isotopologues for investigating the Cycle of Atmospheric water) a commercial Picarro Analyzer L2120-i is operated at Karlsruhe in Southwestern Germany, which is continuously measuring the isotopologues H216O, HDO and H218O of atmospheric water vapor since January 2012. A one year record of H216O, HDO and H218O shows clear seasonal, synoptic and diurnal characteristics and reveals the main driving processes affecting the isotopic composition of water vapor in the Middle European BL. Changes in continental plant transpiration and evaporation throughout the year lead to a slow seasonal HDO/H216O-variation, that cannot be explained by pure Rayleigh condensation. Furthermore, cold-front passages from NW lead to fast and pronounced depletion of the HDO/H216O-ratio within

  10. Formula for Determining Number of Basic Seedlings at Scattered-Planting with Seedling Dry-Raised on Plastic Trays in Double-Season Rice

    Institute of Scientific and Technical Information of China (English)

    PAN Xiao-hua; CHEN Xiao-rong; YANG Fu-sun

    2006-01-01

    The tiller emergence in seedling nursery beds and field, and panicle formation in the field were investigated under scattered-planting with seedling dry-raised on plastic trays in double-season rice. A significant difference was noted in the non-synchronously-emerged tillers (the tillers that formed from latent buds and did not emerge following the normal tillering law on seedling nursery beds and recovered to grow after scattered-planting or transplanting) as well as the percentage of the available synchronously-emerged tillers between seedlings raised on plastic trays under dry-land conditions (DPT) and seedlings raised on nursery beds under wetland conditions (WB). The seedlings under DPT had some non-synchronously-emerged tillers, but those under WB had not. Therefore, the traditional formula for determining the number of rice seedlings was improved, and the formula for determining the number of basic seedlings under scattered planting with DPT in double-season rice was introduced. For early rice, it was X=YI{(1+t1r1)[1+(N-n-SN)Rr2]+(SN-3-t1)R2r5}, and for late rice, it was X=YI{(1+t1r1)[1+(N-n-SN)Rr2]+(N-n-SN-3)Rr2R1r3+(SN-3-t1)R2r5}. Where, X represents reasonable number of basic seedlings per unit area at scattered-planting; Y,number of fitting panicles per unit area; t1, total number of tillers per plant; r1, percentage of the total available tillers; N, total number of leaves of the main culm; n, total number of elongated internodes in the main culm; SN, seedling leaf ages at scattered-planting; R,percentage of the primary tillers emerged in available node-position; r2, percentage of the available primary tillers; R1, percentage of the secondary tillers in the field (except the secondary tillers of the seedlings); r3, percentage of the available secondary tillers; R2,percentage of the asynchronously-emerged tillers after scattered-planting; r5, percentage of the available non-synchronously-emerged tillers after scattered-planting.

  11. Seasonal controls on snow distribution and aerial ablation at the snow-patch and landscape scales, McMurdo Dry Valleys, Antarctica

    Directory of Open Access Journals (Sweden)

    J. W. Eveland

    2012-09-01

    Full Text Available Accumulated snow in the McMurdo Dry Valleys, while limited, has great ecological significance to subnivian soil environments. Though sublimation dominates the ablation process in this region, measurable increases in soil moisture and insulation from temperature extremes provide more favorable conditions with respect to subnivian soil communities. While precipitation is not substantial, significant amounts of snow can accumulate, via aeolian redistribution, in topographic lees along the valley bottoms, forming thousands of discontinuous snow patches. These patches have the potential to act as significant sources of local melt water, controlling biogeochemical cycling and the landscape distribution of microbial communities. Therefore, determining the spatial and temporal dynamics of snow at multiple scales is imperative to understanding the broader ecological role of snow in this region.

    High-resolution satellite imagery acquired during the 2009–2010 and 2010–2011 austral summers was used to quantify the distribution of snow across Taylor and Wright Valleys. Extracted snow-covered area from the imagery was used as the basis for assessing seasonal variability and seasonal controls on accumulation and ablation of snow at multiple scales. In addition, fifteen 1 km2 plots (3 in each of 5 study regions were selected to assess the prevalence of snow cover at finer spatial scales. Results confirm that snow patches tend to form in the same locations each year with some minor deviations observed. At the snow-patch scale, neighboring patches often exhibit considerable differences in aerial ablation rates, and particular snow patches do not reflect trends for snow-covered area observed at the landscape scale. These differences are presumably related to microtopographic influences over snow depth and exposure. This highlights the importance of both the landscape and snow-patch scales in assessing the effects of snow cover on

  12. The relationship of meteorological patterns with changes in floristic richness along a large elevational gradient in a seasonally dry region of southern Mexico

    Science.gov (United States)

    Salas-Morales, Silvia H.; Meave, Jorge A.; Trejo, Irma

    2015-12-01

    Globally, climate is a fundamental driver of plant species' geographical distributions, yet we still lack a good understanding of climatic variation on tropical mountains and its consequences for elevational floristic patterns. In a seasonally dry region of southern Mexico, we analysed meteorological patterns along a large elevational gradient (0-3670 m a.s.l.) and examined their relationship with changes in floristic richness. Meteorological patterns were characterised using two data sources. First, climatic information was extracted from cartography and records from a few existing meteorological stations. Additionally, air temperature and humidity were recorded hourly during 1 year with data loggers, at sites representing 200-m elevation increments. Floristic information was extracted from a database containing 10,124 records of plant collections, and organized in 200-m elevational belts. Climatic charts distinguished three climate types along the gradient, all with marked rainfall seasonality, but these bore little correspondence with the information obtained with the data loggers. Mean annual air temperature decreased with increasing elevation (lapse rate of 0.542 °C 100 m-1). Thermal oscillation was minimum around 1400 m and increased towards both extremes of the gradient. Relative humidity opposed this pattern, with maxima between 800 and 1800 m, decreasing towards the highest elevations. An analysis of temperature frequency distributions revealed meteorological features undetectable from the annual or monthly means of this variable; despite an overall gradual transition of the proportions of time recorded at different temperatures, some changes did not conform to this pattern. The first discontinuity occurred between 1000-1200 m, where dominant temperatures shifted abruptly; also noticeable was an abrupt increase of the proportion of time elapsed at 0.1-10 °C between 2400 and 2600 m. Air temperature appears to be the most influential climatic factor

  13. Intercomparison of AirMISR, CAR, and MISR Observations of Bidirectional Reflectance Factor, Mongu Tower, Zambia, During SAFARI 2000 Dry Season Campaign

    Science.gov (United States)

    Conel, J. E.; Abdou, W. A.; Pilorz, S. H.; Diner, D. J.; Privette, J. L.; Gatebe, C. K.; Holben, B. L.; Exk, T.; King, M. D.

    2001-12-01

    The SAFARI 2000 Dry Season Campaign was carried out across southern Africa in August and September, 2000. The campaign had as goals: (1) study of aerosol sources, transport, modification, and deposition, (2) the impact of atmospheric constituents on African ecosystems, (3) the field measurement of surface reflectance and atmospheric aerosol properties, and (4) measurement of atmospheric and surface properties from MISR and other instruments aboard TERRA. The validation of space platform measurements would permit extension in space and time of the platform measurements. An integral component was making coordinated observations by surface and aircraft measurements. The present work focussed on validation of bidirectional reflectance factor (BRF) by the Multiangle Imaging SpectroRadiometer (MISR, the TERRA Platform), the Cloud Absorption Radiometer (CAR, GSFC, CV-580 Aircraft, University of Washington), and AirMISR (ER-2, NASA DFRC, JPL). Numerous sorties were flown by both the ER-2 (20 km altitude) and CV-580 (altitude ~1 km). A single coincident flight covering miombo woodland was achieved at Mongu Tower (-15.438 deg lat, 23.253 deg long) on Sept 06, 2000 under cloud-free but hazy conditions. BRF intrcomparisons are under development between MISR (Sept 10, 2000 overpass) AirMISR and CAR. The value of CAR is that a bidirectional reflectance is measured rapidly over all azimuths and can be used to compare BRF at other azimuths of observation such as those of AirMISR and MISR. Twenty three BRF recoveries from MISR have subsequently been made covering the interval Sept. 06, 2000 - July 25, 2001. These are under screening for residual clouds to seek seasonal or other reflectance variations present. Such MISR time series provide basis for study of system impacts on a multiyear basis, a principal goal of the SAFARI 2000 experiment.

  14. Potential Sources of Trace Metals and Ionic Species in PM2.5 in Guadalajara, Mexico: A Case Study during Dry Season

    Directory of Open Access Journals (Sweden)

    Mario Alfonso Murillo-Tovar

    2015-12-01

    Full Text Available This study was conducted from May 25 to June 6, 2009 at a downtown location (Centro and an urban sector (Miravalle site in the Metropolitan Zone of Guadalajara (MZG in Mexico. The atmospheric concentrations of PM2.5 and its elemental and inorganic components were analyzed to identify their potential sources during the warm dry season. The daily measurements of PM2.5 (24 h exceeded the WHO (World Health Organization air quality guidelines (25 μg·m−3. The most abundant element was found to be Fe, accounting for 59.8% and 72.2% of total metals mass in Centro and Miravalle, respectively. The enrichment factor (EF analysis showed a more significant contribution of non-crustal sources to the elements in ambient PM2.5 in Centro than in the Miravalle site. Particularly, the highest enrichment of Cu suggested motor vehicle-related emissions in Centro. The most abundant secondary ionic species (NO3−; SO42− and NH4+ and the ratio NO3−/SO42− corroborated the important impact of mobile sources to fine particles at the sampling sites. In addition, the ion balance indicated that particles collected in Miravalle experienced neutralization processes likely due to a higher contribution of geological material. Other important contributors to PM2.5 included biomass burning by emissions transported from the forest into the city.

  15. Ameliorative effects of melatonin administration and photoperiods on diurnal fluctuations in cloacal temperature of Marshall broiler chickens during the hot dry season.

    Science.gov (United States)

    Sinkalu, Victor O; Ayo, Joseph O; Adelaiye, Alexander B; Hambolu, Joseph O

    2015-01-01

    Experiments were performed with the aim of determining the effect of melatonin administration on diurnal fluctuations in cloacal temperature (CT) of Marshall broiler chickens during the hot dry season. Birds in group I (12L:12D cycle) were raised under natural photoperiod of 12-h light and 12-h darkness, without melatonin supplementation, while those in group II (LL) were kept under 24-h continuous lighting, without melatonin administration. Broiler chickens in group III (LL + melatonin) were raised under 24-h continuous lighting, with melatonin supplementation at 0.5 mg/kg per os. The cloacal temperatures of 15 labeled broiler chickens from each group were measured at 6:00, 13:00, and 19:00 h, 7 days apart, from days 14-42. Temperature-humidity index was highest at day 14 of the study, with the value of 36.72 ± 0.82 °C but lowest at day 28 with the value of 30.91 ± 0.80 °C (P chickens but was delayed till day 42 in LL + MEL broiler chickens. In conclusion, melatonin administration alleviated the deleterious effects of heat stress on broiler chickens by maintaining their cloacal temperature at relatively low values.

  16. Ameliorative effects of melatonin administration and photoperiods on diurnal fluctuations in cloacal temperature of Marshall broiler chickens during the hot dry season

    Science.gov (United States)

    Sinkalu, Victor O.; Ayo, Joseph O.; Adelaiye, Alexander B.; Hambolu, Joseph O.

    2015-01-01

    Experiments were performed with the aim of determining the effect of melatonin administration on diurnal fluctuations in cloacal temperature (CT) of Marshall broiler chickens during the hot dry season. Birds in group I (12L:12D cycle) were raised under natural photoperiod of 12-h light and 12-h darkness, without melatonin supplementation, while those in group II (LL) were kept under 24-h continuous lighting, without melatonin administration. Broiler chickens in group III (LL + melatonin) were raised under 24-h continuous lighting, with melatonin supplementation at 0.5 mg/kg per os. The cloacal temperatures of 15 labeled broiler chickens from each group were measured at 6:00, 13:00, and 19:00 h, 7 days apart, from days 14-42. Temperature-humidity index was highest at day 14 of the study, with the value of 36.72 ± 0.82 °C but lowest at day 28 with the value of 30.91 ± 0.80 °C ( P melatonin-treated group but lower than that of 41.65 ± 0.03 °C obtained in the LL birds. Mortality due to hyperthermia commenced at day 28 in both 12L:12D cycle and LL broiler chickens but was delayed till day 42 in LL + MEL broiler chickens. In conclusion, melatonin administration alleviated the deleterious effects of heat stress on broiler chickens by maintaining their cloacal temperature at relatively low values.

  17. Up-regulation of milk secretion with modified microclimate through manipulating plasminogen-plasmin system in Murrah buffaloes during hot dry season

    Science.gov (United States)

    Haque, N.; Singh, M.; Hossain, S. A.

    2016-12-01

    The present study was aimed at determining changes in milk yield and composition along with the plasminogen-plasmin system of milk, plasma hormones, and metabolites of buffaloes during hot dry season (air temperature range 39.7 to 44.8 °C) under two different management systems. Buffaloes were divided in two groups of six animals each: control and treatment, where treatment group animals accessed benefit of mist and fan cooling from 9:30 a.m. to 5:00 p.m., while control group animals were devoid of it. Duration of experiment was 6 weeks. Under mist and fan cooling system, buffaloes experienced better comfort by alleviating environmental stress as their physiological responses such as rectal temperature, respiration rate, pulse rate, and forehead and middorsal temperatures were significantly ( P milk yield by 4.44 % ( P milk samples revealed higher concentration of plasminogen (7.99 vs 6.27 μg/ml; P calcium content of milk, GH, and epinephrine level in plasma. Hence, it may be concluded that provision of cooling system during summer was effective to minimize environmental stress and improve milk production by manipulation of the PG-PL system in buffaloes.

  18. Up-regulation of milk secretion with modified microclimate through manipulating plasminogen-plasmin system in Murrah buffaloes during hot dry season

    Science.gov (United States)

    Haque, N.; Singh, M.; Hossain, S. A.

    2016-05-01

    The present study was aimed at determining changes in milk yield and composition along with the plasminogen-plasmin system of milk, plasma hormones, and metabolites of buffaloes during hot dry season (air temperature range 39.7 to 44.8 °C) under two different management systems. Buffaloes were divided in two groups of six animals each: control and treatment, where treatment group animals accessed benefit of mist and fan cooling from 9:30 a.m. to 5:00 p.m., while control group animals were devoid of it. Duration of experiment was 6 weeks. Under mist and fan cooling system, buffaloes experienced better comfort by alleviating environmental stress as their physiological responses such as rectal temperature, respiration rate, pulse rate, and forehead and middorsal temperatures were significantly (P animals. However, exposure of buffaloes to cooling system did not alter composition and calcium content of milk, GH, and epinephrine level in plasma. Hence, it may be concluded that provision of cooling system during summer was effective to minimize environmental stress and improve milk production by manipulation of the PG-PL system in buffaloes.

  19. Seasonal dynamics of CO2 efflux in soils amended with composted and thermally-dried sludge as affected by soil tillage systems in a semi-arid agroecosystem

    Science.gov (United States)

    García-Gil, Juan Carlos; Soler-Rovira, Pedro; López-de-Sa, Esther G.; Polo, Alfredo

    2014-05-01

    In semi-arid agricultural soils, seasonal dynamic of soil CO2 efflux (SCE) is highly variable. Based on soil respiration measurements the effects of different management systems (moldboard plowing, chisel and no-tillage) and the application of composted sludge (CS) and thermally-dried sewage sludge (TSS) was investigated in a long-term field experiment (28 years) conducted on a sandy-loam soil at the experimental station 'La Higueruela' (40o 03'N, 4o 24'W). Both organic amendments were applied at a rate of 30 Mg ha-1 prior to tillage practices. Unamended soils were used as control for each tillage system. SCE was moderate in late spring (2.2-11.8 μmol CO2 m-2 s-1) when amendments were applied and tillage was performed, markedly decreased in summer (0.4-3.2 μmol CO2 m-2 s-1), following a moderate increase in autumn (3.4-14.1 μmol CO2 m-2 s-1), rising sharply in October (5.6-39.8 μmol CO2 m-2 s-1 ). In winter, SCE was low (0.6-6.5 μmol CO2 m-2 s-1). In general, SCE was greater in chisel and moldboard tilled soils, and in CS and particularly TSS-amended soils, due to the addition of labile C with these amendments, meanwhile no-tillage soils exhibited smaller increases in C efflux throughout the seasons. Soil temperature controlled the seasonal variations of SCE. In summer, when drought occurs, a general decrease of SCE was observed due to a deficit in soil water content. After drought period SCE jumped to high values in response to rain events ('Birch effect') that changed soil moisture conditions. Soil drying in summer and rewetting in autumn may promotes some changes on the structure of soil microbial community, affecting associated metabolic processes, and enhancing a rapid mineralization of water-soluble organic C compounds and/or dead microbial biomass that acts as an energy source for soil microorganisms. To assess the effects of tillage and amendments on SCE, Q10 values were calculated. Data were grouped into three groups according to soil moisture (0

  20. 冷应激及包埋对乳酸菌冻干发酵剂的影响%Effect of cold shock and embedding on the freezing dried lactic acid bacteria culture

    Institute of Scientific and Technical Information of China (English)

    陈贺佳; 牟光庆

    2012-01-01

    Freezing dried lactic acid bacteria culture was prepared by strains matching ratios of Streptococcus thermophils, Lactobacillus bulgaricus, Lactobacillus acidophilus are 3:2:1. Effects of cold shock treatment with different temperatures on survival rate of freezing dried bacteria were studied. The results show that survival rate of lactic acid bacteria after freeze drying was 96.3% under cold shock of 20℃, deal with 4h. The immobilization conditions for fermentation were as follows: sodium alginate 2.25g/L, CaCl2 4.0g/L, and the survival rate of lactic acid bacteria after embedding was 95.6%.%将嗜热链球菌、保加利亚乳杆菌、嗜酸乳杆菌按3∶2∶1比例制备乳酸菌冻干发酵剂.比较不同温度冷应激处理对乳酸菌冻干存活率的影响,结果表明,20℃,处理4h时,冻干存活率为96.3%.选择发酵的固定化细胞制作条件:海藻酸钠2.25g/L、CaCl2 4.0g/L.包埋后乳酸菌冻干存活率为95.6%.

  1. HPPMS (Cr1-xAlx)N WSy Coatings for the Application in Dry Cold Forging of Steel: Sythesis and Raman Characterization

    OpenAIRE

    Bobzin, Kirsten

    2016-01-01

    Lubricants are applied to reduce friction between workpieces and forming tools in cold forging processes. There is a strong demand to avoid lubricants due to economic, ecological and legislative aspects. PVD coatings took over the tasks of lubricants in numerous applications in the recent years. They may enormously reduce tool and workpiece wear in cold forging or deliver special functions even in the absence of lubricants. However, the abdication of lubricants goes along with the requirement...

  2. Physical properties of the sub-micrometer aerosol over the Amazon rain forest during the wet-to-dry season transition - comparison of modeled and measured CCN concentrations

    Directory of Open Access Journals (Sweden)

    J. Rissler

    2004-01-01

    Full Text Available Sub-micrometer atmospheric aerosol particles were studied in the Amazon region, 125 km northeast of Manaus, Brazil (-1°55.2'S, 59°28.1'W. The measurements were performed during the wet-to-dry transition period, 4-28 July 2001 as part of the LBA (Large-Scale Biosphere Atmosphere Experiment in Amazonia CLAIRE-2001 (Cooperative LBA Airborne Regional Experiment experiment. The number size distribution was measured with two parallel differential mobility analyzers, the hygroscopic growth at 90% RH with a Hygroscopic Tandem Mobility Analyzer (H-TDMA and the concentrations of cloud condensation nuclei (CCN with a cloud condensation nuclei counter. A model was developed that uses the H-TDMA data to predict the number of soluble molecules or ions in the individual particles and the corresponding minimum particle diameter for activation into a cloud droplet at a certain supersaturation. Integrating the number size distribution above this diameter, CCN concentrations were predicted with a time resolution of 10 min and compared to the measured concentrations. During the study period, three different air masses were identified and compared: clean background, air influenced by aged biomass burning, and moderately polluted air from recent local biomass burning. For the clean period 2001, similar number size distributions and hygroscopic behavior were observed as during the wet season at the same site in 1998, with mostly internally mixed particles of low diameter growth factor (~1.3 taken from dry to 90% RH. During the periods influenced by biomass burning the hygroscopic growth changed slightly, but the largest difference was seen in the number size distribution. The CCN model was found to be successful in predicting the measured CCN concentrations, typically within 25%. A sensitivity study showed relatively small dependence on the assumption of which model salt that was used to predict CCN concentrations from H-TDMA data. One strength of using H-TDMA data

  3. A study of turbulent fluxes and their measurement errors for different wind regimes over the tropical Zongo glacier (16° S during the dry season

    Directory of Open Access Journals (Sweden)

    M. Litt

    2015-01-01

    Full Text Available Over glaciers in the outer tropics, during the dry winter season, turbulent fluxes are an important sink of melt energy due to high sublimation rates, but measurements in stable surface layers, in remote and complex terrains remain challenging. Eddy-covariance (EC and bulk-aerodynamic (BA methods were used to estimate surface turbulent heat fluxes of sensible (H and latent heat (LE in the ablation zone of the tropical Zongo glacier, Bolivia (16° S, 5080 m a.s.l., from 22 July to 1 September 2007. We studied the turbulent fluxes and their associated random and systematic measurement errors under the three most frequent wind regimes. For nightly, density-driven katabatic flows, and for strong downslope flows related to large-scale forcing, H generally heats the surface (i.e., is positive, while LE cools it down (i.e., is negative. On average, both fluxes exhibit similar magnitudes and cancel each other out. Most energy losses through turbulence occur for daytime upslope flows, when H is weak due to small temperature gradients and LE is strongly negative due to very dry air. Mean random errors of the BA method (6% on net H + LE fluxes originated mainly from large uncertainties in roughness lengths. For EC fluxes, mean random errors were due mainly to poor statistical sampling of large-scale outer-layer eddies (12%. The BA method is highly sensitive to the method used to derive surface temperature from long-wave radiation measurements and underestimates fluxes due to vertical flux divergence at low heights and nonstationarity of turbulent flow. The EC method also probably underestimates the fluxes, but to a lesser extent, due to underestimation of vertical wind speed and to vertical flux divergence. For both methods, when H and LE compensate each other in downslope fluxes, biases tend to cancel each other out or remain small. When the net turbulent fluxes (H + LE are the largest in upslope flows, nonstationarity effects and underestimations of the

  4. A study of turbulent fluxes and their measurement errors for different wind regimes over the tropical Zongo Glacier (16° S during the dry season

    Directory of Open Access Journals (Sweden)

    M. Litt

    2015-08-01

    Full Text Available Over glaciers in the outer tropics, during the dry winter season, turbulent fluxes are an important sink of melt energy due to high sublimation rates, but measurements in stable surface layers in remote and complex terrains remain challenging. Eddy-covariance (EC and bulk-aerodynamic (BA methods were used to estimate surface turbulent heat fluxes of sensible (H and latent heat (LE in the ablation zone of the tropical Zongo Glacier, Bolivia (16° S, 5080 m a.s.l., from 22 July to 1 September 2007. We studied the turbulent fluxes and their associated random and systematic measurement errors under the three most frequent wind regimes. For nightly, density-driven katabatic flows, and for strong downslope flows related to large-scale forcing, H generally heats the surface (i.e. is positive, while LE cools it down (i.e. is negative. On average, both fluxes exhibit similar magnitudes and cancel each other out. Most energy losses through turbulence occur for daytime upslope flows, when H is weak due to small temperature gradients and LE is strongly negative due to very dry air. Mean random errors of the BA method (6 % on net H + LE fluxes originated mainly from large uncertainties in roughness lengths. For EC fluxes, mean random errors were due mainly to poor statistical sampling of large-scale outer-layer eddies (12 %. The BA method is highly sensitive to the method used to derive surface temperature from longwave radiation measurements and underestimates fluxes due to vertical flux divergence at low heights and nonstationarity of turbulent flow. The EC method also probably underestimates the fluxes, albeit to a lesser extent, due to underestimation of vertical wind speed and to vertical flux divergence. For both methods, when H and LE compensate each other in downslope fluxes, biases tend to cancel each other out or remain small. When the net turbulent fluxes (H + LE are the largest in upslope flows, nonstationarity effects and underestimations of the

  5. The study of the chatchment area and hydrodinamics of Árbol de Navidad (Chiapas, Mexico) to solve the problem of its feeding during the dry season

    Science.gov (United States)

    De Matteo, Ada; Bernabei, Tullio; Davila Garcia, Luis I.; Del Vecchio, Umberto; Forti, Paolo; Zarate Galvez, Kaleb

    2016-04-01

    The Sumidero Canyon, and its surrounding National Park is one of the most remarkable natural sites in the State of Chiapas, Mexico. Its principal attraction is the 200 m waterfall called "Árbol de Navidad" (Christmas tree), situated about 175 m above the river, close to the Chicoasén dam. The Árbol de Navidad is characterized by its own particular ecosystem and by the presence of a travertine formation flowing out from a little cave, with a characteristic form from which derives its name. The cave from which the Árbol de Navidad takes origin is a karst spring fed by water infiltration from somewhere in the highland behind. In the last years the flow rate decreased drastically and disappeared completely during few months every years. Since the importance of this natural marvel, with high naturalistic, cultural, and touristic interests, local authorities asked La Venta Exploring Team and its Mexican branch CEKLAV (Centro de Estudios Kársticos La Venta) to lead a research aimed to understand the causes of this decreasing and to formulate suggestions to rescue and maintain the waterfall. The project, called "Guardianes del Árbol" (Tree Guardian) consists of several steps: 1- inspection of the spring cave to verify the presence of possible obstructions; 2- search for the principal karst sinkholes located on highland behind; geological and hydrogeological study of the highland; 3- hydrological tracing, to understand the hydrogeological system which fed the waterfall; 4- potential solutions for rescue and maintenance. At the moment the first step has been concluded and the second and third steps are on the way. The first results were the complete cleaning of the underground river which was rather completely filled by sand, mud and roots thus avoiding the water circulation during the dry season. During the beginning of the second and third steps a detailed structural analysis has been carried out in order to detect the possible recharge areas for the Árbol. Then two

  6. 珠江口枯季盐通量数值模拟研究%Numerical Simulation of Salt Flux in Dry Season in the Pearl River Delta

    Institute of Scientific and Technical Information of China (English)

    危小艳; 诸裕良; 张蔚; 孙世伟

    2012-01-01

    The salt flux of the Pearl River Delta in dry season is simulated with a 2-D numerical model, the range of which includes both the river network of the delta and the eight river mouths of the Pearl. The results of the study match well with the observed data, that implies the model is capable of describing the temporal and spatial distribution of salt current and simulating the salt flux in the Pearl River Delta. The salt flux in dry season during spring tide is 1 950*104t, while that during neap tide is 510×104t, only 26.18% of the former. The salt flux in Dahu and Guanchong are the highest in the 8 stations of the river mouths, indicating that Humen and Yamen are the main entries for saltwater intrusion in the delta. Owing to the changes of the salinity, the river channel terrain and water flux in different cross sections. Decrease of salt flux along the Lion Bay is obvious. Salinity distribution during spring tide and neap tide shows that saltwater intrusion is much more serious during spring tide, and at that time water supply for drinking, irrigation or for ecological purpose in Panyu and Guangzhou is affected.%采用数学模型手段对珠江河口的盐通量进行了计算和分析.该平面二维水流盐度模型范围包括珠江三角洲河网与八大口门在内,计算结果与实测值符合良好,较好地反映了模拟区域盐度场的时空分布特点.结果显示:珠江河口枯季大潮时的总盐通量为1 954×104t,小潮时总盐通量为512×104t,仅为大潮时的26.2%;无论是在大潮还是小潮期间,大虎和官冲的盐通量所占比例最大,说明盐水入侵主要是通过虎门与崖门这两个通道进入;盐通量沿程明显减少,这是盐度、水通量等沿程变化的综合作用.不同类型水体的盐度等值线在枯季大小潮期间的分布情况表明,盐水入侵在大潮期间明显比小潮更严重,已经影响到番禺、广州部分地区的饮用水、灌溉用水和生态用水的正常使用.

  7. Seasonal controls on snow distribution and aerial ablation at the snow-patch and landscape scales, McMurdo Dry Valleys, Antarctica

    Directory of Open Access Journals (Sweden)

    J. W. Eveland

    2013-06-01

    Full Text Available Accumulated snow in the McMurdo Dry Valleys, while limited, has great ecological significance to subnivian soil environments. Though sublimation dominates the ablation process in this region, measurable increases in soil moisture and insulation from temperature extremes provide more favorable conditions with respect to subnivian soil communities. While precipitation is not substantial, significant amounts of snow can accumulate, via wind transport, in topographic lees along the valley bottoms, forming thousands of discontinuous snow patches. These patches have the potential to act as significant sources of local meltwater, controlling biogeochemical cycling and the landscape distribution of microbial communities. Therefore, determining the spatial and temporal dynamics of snow at multiple scales is imperative to understanding the broader ecological role of snow in this region. High-resolution satellite imagery acquired during the 2009–2010 and 2010–2011 austral summers was used to quantify the distribution of snow across Taylor and Wright valleys. Extracted snow-covered area from the imagery was used as the basis for assessing inter-annual variability and seasonal controls on accumulation and ablation of snow at multiple scales. In addition to landscape analyses, fifteen 1 km2 plots (3 in each of 5 study regions were selected to assess the prevalence of snow cover at finer spatial scales, referred to herein as the snow-patch scale. Results confirm that snow patches tend to form in the same locations each year with some minor deviations observed. At the snow-patch scale, neighboring patches often exhibit considerable differences in aerial ablation rates, and particular snow patches do not reflect trends for snow-covered area observed at the landscape scale. These differences are presumably related to microtopographic influences acting on individual snow patches, such as wind sheltering and differences in snow depth due to the underlying

  8. "I eat the manofê so it is not forgotten": local perceptions and consumption of native wild edible plants from seasonal dry forests in Brazil.

    Science.gov (United States)

    Cruz, Margarita Paloma; Medeiros, Patrícia Muniz; Sarmiento-Combariza, Iván; Peroni, Nivaldo; Albuquerque, Ulysses Paulino

    2014-05-23

    There is little information available on the factors influencing people's selection of wild plants for consumption. Studies suggest a suitable method of understanding the selection of edible plants is to assess people's perceptions of these resources. The use and knowledge of wild resources is disappearing, as is the opportunity to use them. This study analyzes people's perceptions of native wild edible plants in a rural Caatinga (seasonal dry forest) community in Northeast Brazil and the relationships between the use of these resources and socioeconomic factors. Semi-structured interviews with 39 people were conducted to form a convenience sample to gather information regarding people's perceptions of 12 native wild edible plant species. The relationships between variables were assessed by simple linear regression analysis, Pearson and Spearman correlation analyses, and in the case of nominal variables, contingency tables. The discourse of participants regarding their opinions of the use of wild plants as food was analyzed through the collective subject discourse analysis technique. Perceptions were classified into 18 categories. The most cited category was organoleptic characteristics of the edible part; more specifically, flavor. Flavor was the main positive perception associated with plant use, whereas the negative perception that most limited the use of these plants was cultural acceptance. Perceptions of the use of wild edible plants were directly correlated with both interviewee age and income. Within the studied community, people's perceptions of native wild edible plants are related to their consumption. Moreover, the study found that young people have less interest in these resources. These findings suggest that changing perceptions may affect the conservation of plants, traditional practices and the associated knowledge.

  9. PBL Aerosols SE of Mexico City in the dry Season: Biomass Burning and Windblown Dust and its Impact on Photolysis Frequencies

    Science.gov (United States)

    Junkermann, W.; Grutter, M.; Baumgardner, D.; Steinbrecher, R.

    2007-05-01

    During the dry season in March 2006 airborne investigations on aerosol distributions, ultraviolet actinic radiation and ozone profiles were performed southeast of Mexico City using an ultralight aircraft as a mobile platform. The area investigated covered the rural area southeast of Mexico City, the Chalco Valley, Huexca and Atlixco south of the volcano Popocatepetl, east of Paso de Cortés to the airport of Puebla and the pass between Puebla and Mexico City north of the volcano Ixtachiuatl. The Chalco valley is the main venting valley of the Mexico City basin to the south. Intense biomass burning was observed on both slopes of the volcanoes leading to strong pyrocumulus cloud production in the northern part of the national reserve and above the motorway Puebla-Mexico. Fine particle (> 10 nm) numbers reached up to 80000/cm3 close to the burning plumes with significant reduction to ~ 30-40000/cm3 in the Chalco valley where coarse particles (> 300 nm) dominated the total mass. Dust devils transporting coarse soil particles up to elevations of more than 4000 m a.s.l. were frequently observed. Particles and air masses of pollution sources in the area can be characterized by aerosol size distributions and/or spectral absorption from multi-wavelength aethalometer measurements as well as from ozone mixing ratios and meteorological data measured onboard. The aerosol impact on photolysis rates and air chemistry is derived from vertical profiles of actinic radiation in the JO1D and JNO2 spectral regimes at 300 nm and 380 nm, respectively. Profiles were flown on both sides of the volcano ridge, south of Popocatepetl and above Tenango del Aire where aircraft measurements were supported by ceilometer aerosol vertical profiles.

  10. Effect of dry and cold environment on the weight and diet of COPD rats%寒燥对慢性阻塞性肺疾病模型大鼠体质量及饮食量的影响

    Institute of Scientific and Technical Information of China (English)

    高振; 李风森; 荆晶; 徐丹; 哈木拉提·吾甫尔

    2012-01-01

    目的:揭示寒燥对慢性阻塞性肺疾病(COPD)模型大鼠体质量及饮食量的影响,为西北特点COPD防治措施的制定提供参考.方法:利用气管滴注弹性蛋白酶结合熏烟建立COPD模型大鼠36只,在此基础上复合寒燥应激建立COPD寒燥模型18只,并设立对照组13只,每只大鼠的体质量和每组大鼠饮食量结果用SPSS 11.5分析.结果:COPD组及COPD寒燥组体质量指数(BMI)和Lee's指数均小于对照组(P<0.01),且COPD寒燥组此3项指标均小于COPD组(P<0.05,P<0.01).COPD寒燥组每10g体质量每天进食量大于对照组和COPD组.结论:寒燥可以加剧并提前COPD模型体质量减轻和营养不良的症状,并增加进食量,但此状态非仅靠增加一般饮食可以改善.%Objective: To reveal the effect of cold and dry environment on weight and diet of the COPD model, so as to provide reference for treating COPD with local peculiarity of the northwest of China. Methods: COPD model was established by dripping porcine pancreatic elastase (PEE) in trachea combination with cigarette smoking, and model of cold dryness syndrome in northwest China of COPD was also set up by dripping PEE in trachea in combination with cigarette smoking for cold-dry environmental stress. SPSS11.5 were used to analysis rat's weight and diet. Results: the weight of COPD cold and dryness group was less than the COPD group, less than the control group; for Lee's index, and BMI COPD cold and dryness group was more than the COPD group, more than the control group. Conclusion: Cold and dryness can ahead of the weight loss and malnutrition and increase food intake, but this state can't be improved only by increasing the general diet.

  11. Seasonal variation of the protozooplanktonic community in a tropical oligotrophic environment (Ilha Solteira reservoir, Brazil

    Directory of Open Access Journals (Sweden)

    AS Mansano

    Full Text Available The seasonal variation of the protozooplanktonic community (ciliates and testate amoebae was studied in a tropical oligotrophic reservoir in Brazil, which was under the influence of two contrasting climatic seasons (rainy/warm and dry/cold. The aim of this study was to evaluate the effect of these climatic changes on physical, chemical and biological variables in the dynamic of this community. The highest mean density of total protozoans occurred in the rainy/warm season (5683.2 ind L−1, while the lowest was in the dry/cold (2016.0 ind L−1. Considering the seasonal variations, the protozoan groups that are truly planktonic, such as the oligotrichs (Spirotrichea, predominated in the dry season, whereas during the rainy season, due to the material input and resuspension of sediment, sessile protozoans of the Peritrichia group were the most important ones. The dominant protozoans were Urotricha globosa, Cothurnia annulata, Pseudodifflugia sp. and Halteria grandinella. The highest densities of H. grandinella were associated with more oxygenated and transparent water conditions, while the highest densities of C. annulata occurred in sites with high turbidity, pH and trophic state index (TSI. The study demonstrated that density and composition of protozooplanktonic species and groups of the reservoir suffered seasonal variation due to the environmental variables (mainly temperature, turbidity, water transparency, dissolved oxygen and TSI and the biological variables (e.g. morphological characteristics, eating habits and escape strategies from predation of the species.

  12. Cold Stress

    Science.gov (United States)

    ... Publications and Products Programs Contact NIOSH NIOSH COLD STRESS Recommend on Facebook Tweet Share Compartir Workers who ... cold environments may be at risk of cold stress. Extreme cold weather is a dangerous situation that ...

  13. Effects of soil moisture retention on ice distribution and active layer thickness subject to seasonal ground temperature variations in a dry loess terrace in Adventdalen, Svalbard.

    Science.gov (United States)

    Schuh, Carina; Frampton, Andrew; Christiansen, Hanne

    2017-04-01

    The active layer constitutes an important part of permafrost environments. Thermal and hydrological processes in the active layer determine local phenomena such as erosion and hydrological and ecosystem changes, and can have important implications for the global carbon-climate feedback. Permafrost degradation usually starts with a deepening of the active layer, followed by the formation of a talik and the subsequent thawing of permafrost. An increasing active layer thickness is therefore regarded as an indicator of permafrost degradation. The importance of hydrology for active layer processes is generally well acknowledged on a conceptual level, however the in general non-linear physical interdependencies between soil moisture, subsurface water and heat fluxes and active layer thaw progression are not fully understood. In this study, high resolution field data for the period 2000-2014 consisting of active layer and permafrost temperature, active layer soil moisture, and thaw depth progression from the UNISCALM research site in Adventdalen, Svalbard, is combined with a physically-based coupled cryotic and hydrogeological model to investigate active layer dynamics. The site is a loess-covered river terrace characterized by dry conditions with little to no summer infiltration and an unsaturated active layer. A range of soil moisture characteristic curves consistent with loess sediments is considered and their effects on ice and moisture redistribution, heat flux, energy storage through latent heat transfer, and active layer thickness is investigated and quantified based on hydro-climatic site conditions. Results show that soil moisture retention characteristics exhibit notable control on ice distribution and circulation within the active layer through cryosuction and are subject to seasonal variability and site-specific surface temperature variations. The retention characteristics also impact unfrozen water and ice content in the permafrost. Although these effects

  14. Supplementation with different energy and protein sources on the feeding behavior and performance of dairy heifers grazing Marandu during the dry season

    Directory of Open Access Journals (Sweden)

    Ricardo Dias Signoretti

    2012-02-01

    Full Text Available This study aimed to evaluate the effect of supplementation different energy and protein sources in the dry season of the year, on body development and diurnal feeding behavior of crossbred Gir x Holstein dairy heifers 12.8 ± 4.6 months old, 215.50 ± 43.2 kg average body weight were distributed in Brachiaria brizantha cv. Marandu pasture with supplements being offered daily in proportion of 0.75% of the body weight. A completely randomized block design with a 2 x 2 factorial arrangement was used, with six replicates per treatment. Supplements contained whole soybean (WS or whole cottonseed (WC as the protein sources and citrus pulp (CPU or corn (C as the energy sources. Marandu grass pasture was managed according a rotational grazing system, six days grazing and 30 days of rest period. It was recorded the animals weight, height at withers, heart girt, rump length and corporal score after the grazing cycle. The considered behavioral variables were grazing time, ruminating time, idle time, trough time. No significant differences on the initial, heart girt, height at withers, rump length and corporal score final and initial to protein and energy sources. However, a significant effect was observed (P<0.05 in heifers supplemented with WC had greater final body weight and heart girt and average daily gain live weight (271.1 kg, 152.2 cm and 0.382 kg/animal, respectively in comparison to those with WS (251.1 kg, 148.7 cm and 0.255 kg/animal, respectively. The CPU base supplement resulted in smaller grazing time and greater ruminating and idle time (P>0.05. The WS base supplemented animals had kept lesser time eating supplement in comparison to the WC base supplemented ones (P<0.05, with no variation in grazing, rumination or idle times regarding protein font (P>0.05. The hour of the day influenced all the considered behaviors (P<0.01.

  15. Prevalence and etiology of buffalo mastitis and milk somatic cell count in dry and rainy seasons in a buffalo herd from Analândia, São Paulo State, Brazil

    Directory of Open Access Journals (Sweden)

    L.J.L. Pizauro

    2014-12-01

    Full Text Available The aim of this study was to evaluate somatic cell count (SCC, prevalence and etiology of mastitis in a dairy buffalo herd from Analândia, São Paulo State, Brazil, in the dry and rainy seasons. Additionally, antimicrobial susceptibility profile of microorganisms isolated from milk samples was also evaluated. 1,042 milk samples from female Murrah buffaloes in a dairy farm located in Analândia, São Paulo State, Brazil, collected between May 2011 and November 2012 were analyzed. After the mammary gland physical examination, strip cup test and California Mastitis Test (CMT were performed. Afterwards, 50mL of milk samples from each mammary quarter were collected aseptically for SCC in automatic equipment and microbiological examination. The antimicrobial sensitivity profile to ampicillin, cefoperazone, ceftiofur, enrofloxacin, gentamicin, neomycin, oxacillin, penicillin, and sulfamethoxazole/trimethoprim was evaluated by disk diffusion method. The monthly average temperature and pluviometric index were obtained from "Centro Integrado de Informações Agrometeorológicas" (CIIAGRO of "Instituto Agronômico de Campinas" (IAC. Milk samples with positive results in the microbiological test showed average SCC of 137,720 cells/mL in the dry period and 190,309 cells/mL in the rainy period. Although a higher number of isolated microorganisms was observed in buffalo milk samples during the rainy period (69/600 compared to the dry period (50/442, the season had no significant effect on the frequency of isolation of microorganisms. The main genera of microorganisms isolated were coagulase-negative Staphylococcus (38.4%, Streptococcus agalactiae (28.8%, and Bacillus spp. (7.56% during the dry season and Corynebacterium sp. (23.5%, Streptococcus spp. (32.3%, and Streptococcus agalactiae (9.24% during the rainy period. Multidrug resistance was observed in 30.1% of the isolated microorganisms.

  16. Effect of a cold, dry air incursion on atmospheric boundary layer processes over a high-altitude lake in the Tibetan Plateau

    Science.gov (United States)

    Li, Zhaoguo; Lyu, Shihua; Wen, Lijuan; Zhao, Lin; Ao, Yinhuan; Wang, Shaoying

    2017-03-01

    High-altitude lakes are frequently exposed to extreme meteorological conditions, but the surface and atmospheric boundary layer (ABL) processes have received little attention under specific weather conditions. This study used the multi-source field data, re-analysis and remote sensing data to investigate the varying patterns and driving forces of the convective boundary layer (CBL) height over Ngoring Lake in the Tibetan Plateau (TP) before and after the cold air incursion. Daily cumulative surface heat flux and buoyancy flux over the land were markedly larger than those over the lake on a clear summer day, but an opposite pattern was observed accompanied by the cold air incursion. CBLs determined by the potential temperature thinned (depth < 100 m) over the lake in the daytime and thickened (400-600 m) at night on a clear day. Along with the arrival of the cold air, CBL rapidly thickened to 2280 m over the lake, exceeded than the maximum value at adjacent Madoi station. Cold air dramatically cooled the middle-upper atmosphere but the temperature of the lower atmosphere cooled down slowly, partly due to a sharp increase of sensible heat flux over the lake, both of which linked up to weaken the potential temperature gradient. Moreover, increasing wind speed and vertical wind shear further facilitated the buoyancy flux to exert higher heat convection efficiency. All of these factors acted together to cause the rapid growth of CBL over the lake. This investigation provided a more in-depth knowledge of boundary layer dynamics in the lake-rich region of the TP.

  17. 发酵芹菜粉对风干肠冷藏过程中理化特性的影响%Effect of Fermented Celery Powder on the Physicochemical Properties of Dried Sausage during Cold Storage

    Institute of Scientific and Technical Information of China (English)

    任小青; 刘彩红; 马俪珍

    2015-01-01

    利用发酵芹菜粉(Fermented Celery Powder,FCP ) 替代亚硝酸盐生产风干肠.将3种发酵芹菜粉(FCP506、FCP504、FCPmlz)分别替代亚硝酸盐,同时以添加亚硝酸盐(0.1 g/kg)为阳性对照组(PC),不添加亚硝酸盐为阴性对照组(NC)生产风干肠,探究风干肠成熟后,经过真空包装,在4℃的条件下贮藏4周,FCP对其理化特性的影响.研究结果表明:冷藏期间,5组风干肠的pH、Aw和水分含量变化差异不显著;NC组的TBARS值、TVB-N值明显高于其他4组(P<0.05),NC组的亚硝酸盐残留量、a*值明显低于其他4组(P<0.05),而PC、FCP506、FCP504和FCPmlz 4组之间差异不显著.说明FCP应用于风干肠可以替代亚硝酸盐的发色、抗氧化等作用,为生产天然肉制品奠定了理论基础.%Fermented celery powder (FCP) was used to make the dried sausage in this experiment.Five groups of dried sausages were set up: FCP506,FCP504,FCPmlz,PC (with 0.1 g/kg sodium nitrite) and NC (without sodium nitrite) and the pH,content of water,Aw,nitrite residue,TBARS value,TVB-N value and a*value were measured during cold storage.The results showed during cold storage,Aw,water content and pH in 5 groups of dried sausage were not significant difference;TBARS value and TVB-N value in the dried sausage with NC were significantly higher than the others (P<0.05),nitrite residue and a*value in the dried sausage with NC were significantly lower than the others (P<0.05),and the FCP506,FCP504,FCPmlz and PC group were not significant difference.Therefore,these results indicated that FCP was a useful alternative for cured meat products.

  18. My favorite season

    Institute of Scientific and Technical Information of China (English)

    李清; 凌清兰

    2016-01-01

    As we all know,there are four seasons in a year,they are spring,summer,autumn,and winter.In my eyes,among this four seasons,winter are the most attractive season.In the impression of a lot of people,winter always means cold,windy,the color of gray and lacks energy.On the contrary,to my understanding,winter is not only means a cold weather but also the symbol of hope and beautiful.I love it all the same.In fact,when it comes to winter,the grass has became yellow

  19. Modeling Ice Table Depth, Ground Ice Content, and δD-δ18O of Ground Ice in the Cold Dry Soils of Earth and Mars

    Science.gov (United States)

    Fisher, D. A.; Lacelle, D.; Pollard, W.; Davila, A.; McKay, C. P.

    2016-09-01

    In the upper McMurdo Dry Valleys, ice table depths range from 0 to 80 cm. This study explores the effects of ground temperature and humidity and advective flows on water vapour flux and ice table depth using the REGO vapour-diffusion model.

  20. 低温季节西南亚高山森林土壤轻组分有机碳动态%Dynamics of Light Fraction Organic Carbon in Subalpine Forest Soil in Southwestern China During Cold Season

    Institute of Scientific and Technical Information of China (English)

    秦纪洪; 武艳镯; 孙辉; 马丽红

    2012-01-01

    Soil light fraction organic carbon (LFOC) is regarded as one of the most sensitive indexes of soil labile carbon because the content and turnover ratio is more readily influenced by recent land use and environmental changes than the total organic carbon of soil. The subalpine forest soil in the southwestern China is one vulnerable ecosystem with high altitude and low temperature. The dynamics of LFOC in 0-l0cm and 10-20cm soil with and without liner and/or snow cover of subalpine forest were assessed by on-site incubation of repacked homogenized soil during the cold season. The results showed that LFOC content was 15.5% of the total organic carbon in 0-20cm soil on average, and varied from 13.6% to 21.1% under different treatments with litter cover and/or snowcover after a cold season. Soil LFOC in 0-10cm layer under litter and snow cover was lower than those of other treatment, which indicated that soil surface cover of litter and snow and their combination impacted LFOC content significantly, and the coexsitence of litter and snow was helpful to restrict LFOC formation and to maintain organic carbon stability during the cold season. Different temporal dynamics of LFOC content in I0-20cm layer also showed significant difference under different treatments, indicating that subsoil LFOC were also associated with surface cover. Soil LFOC content and fluctuation were rather high during the cold season, even higher than that in the growth season, which suggested that soil LFOC was active even during the cold season. Litter cover, snowcover, sampling time, soil depth and their interactions affected soil LFOC dynamics in cold season significantly. It was concluded that soil carbon pool size and its stabilization of subalpine forest in the southwestern China would be influenced significantly by the changes of litter and snow cover during the cold season, especially under the global warming and land use changes.%轻组分有机碳(LFOC)易受短期土地利用方式和环

  1. Cold Urticaria

    Science.gov (United States)

    Diseases and Conditions Cold urticaria By Mayo Clinic Staff Cold urticaria (ur-tih-KAR-e-uh) is a skin reaction to cold. Skin that has ... in contact with cold develops reddish, itchy welts (hives). The severity of cold urticaria symptoms varies widely. ...

  2. The ground cherry(cerasus fruticosa Pall).a new kind of edible cherry for cold and dry regions of China

    Institute of Scientific and Technical Information of China (English)

    DingXiaodong; SuiWei; 等

    1994-01-01

    We have conducted some studies on 3 ground cherry cultivars' artaskaja','Bushkaja' and Maksmorfikaja' introduced from Russia,The results indicated that these cultivars could survive temperature-40℃ during severe winter in Harbin,China and had high drought and disease resistance,the average weight of each fruit reached 2.78g,the contents of Vc and soluble solid exceeded 30mg/100g and 12%,respectively.Not only does the fruits suit for fresh market,but also for processing.Ground cherry is a promising new fruit crop in cold region.

  3. Quantification of urban atmospheric boundary layer greenhouse gas dry mole fraction enhancements in the dormant season: Results from the Indianapolis Flux Experiment (INFLUX

    Directory of Open Access Journals (Sweden)

    Natasha L. Miles

    2017-06-01

    Full Text Available We assess the detectability of city emissions via a tower-based greenhouse gas (GHG network, as part of the Indianapolis Flux (INFLUX experiment. By examining afternoon-averaged results from a network of carbon dioxide (CO2, methane (CH4, and carbon monoxide (CO mole fraction measurements in Indianapolis, Indiana for 2011–2013, we quantify spatial and temporal patterns in urban atmospheric GHG dry mole fractions. The platform for these measurements is twelve communications towers spread across the metropolitan region, ranging in height from 39 to 136 m above ground level, and instrumented with cavity ring-down spectrometers. Nine of the sites were deployed as of January 2013 and data from these sites are the focus of this paper. A background site, chosen such that it is on the predominantly upwind side of the city, is utilized to quantify enhancements caused by urban emissions. Afternoon averaged mole fractions are studied because this is the time of day during which the height of the boundary layer is most steady in time and the area that influences the tower measurements is likely to be largest. Additionally, atmospheric transport models have better performance in simulating the daytime convective boundary layer compared to the nighttime boundary layer. Averaged from January through April of 2013, the mean urban dormant-season enhancements range from 0.3 ppm CO2 at the site 24 km typically downwind of the edge of the city (Site 09 to 1.4 ppm at the site at the downwind edge of the city (Site 02 to 2.9 ppm at the downtown site (Site 03. When the wind is aligned such that the sites are downwind of the urban area, the enhancements are increased, to 1.6 ppm at Site 09, and 3.3 ppm at Site 02. Differences in sampling height affect the reported urban enhancement by up to 50%, but the overall spatial pattern remains similar. The time interval over which the afternoon data are averaged alters the calculated urban enhancement by an average of 0.4 ppm

  4. 钦州湾丰水期和枯水期浮游动物群落特征%Characteristics of zooplankton community in the Qinzhou Bay during flood and dry seasons

    Institute of Scientific and Technical Information of China (English)

    蓝文陆; 李天深; 刘勐伶; 庞碧剑; 刘昕明

    2015-01-01

    在2011年丰水期(7月)和2012年枯水期(3月),分别对钦州湾的内湾和外湾开展了浮游动物调查,研究了枯水期和丰水期钦州湾浮游动物的种类组成、数量分布和季节变化特征。丰水期和枯水期浮游动物种类数量分别为27种和44种,以优势度指数Y >0.02确定的优势种丰水期和枯水期分别为3种和4种。丰水期浮游动物丰度为4.0~133.6 ind/m3,平均丰度为50.9 ind/m3;枯水期浮游动物丰度为1.2~1725.0 ind/m3,平均丰度为272.2 ind/m3。丰水期浮游动物(包含鱼卵仔鱼)生物量为1.7~179.2 mg/m3,平均生物量为44.0 mg/m3;枯水期浮游动物(包含鱼卵仔鱼)生物量为3.1~3530.0 mg/m3,平均生物量为474.9 mg/m3。无论是浮游动物的种类数量、丰度和生物量,均显示出内湾低于外湾的空间分布特征,以及枯水期高于丰水期的变化特征。钦州湾浮游动物的这种季节变化和空间分布特征主要是与浮游植物生物量、贝类养殖、环境的稳定度以及人为干扰等有着密切的关系。%The characteristics of species composition,quantitative distribution and seasonal variation of zooplankton in the Qinzhou Bay were investigated in flood season in 2011(July)and dry season in 2012(March).Species quan-tity of zooplankton were 27 and 44 with dominant species(Y>0.02)of 3 and 4 in flood and dry seasons,respective-ly.The dominant species were Acartia (Odontacartia)pacifica,Pleurobrachia globosa and Lucifer intermedius in flood season,while Calanus sinicus ,Pleurobrachia globosa ,Oikopleura (Vexillaria )dioica and Centropages te-nuiremis in dry season.The abundance of zooplankton ranged from 4.01-133.64 ind/m3 with an average of 50.9 ind/m3 in flood season,while 1.2-1 725.0 ind/m3 with an average of 272.2 ind/m3 in dry season.However,bio-mass of zooplankton which included fish eggs and larvae ranged from 1.7-179.2 mg/m3 with

  5. Sustainable energy lessons from domestic architecture of rock villages of cold dry regions of Iran (case studies: Benakohul, Samarkhazan and Hilehvar villages)

    Energy Technology Data Exchange (ETDEWEB)

    Mehmani, Roghaiyeh [Department of Architecture, Bostanabad Branch, Islamic Azad University (Iran, Islamic Republic of)], email: R_sana20@yahoo.com; A' zami, Ahadollah [Department of Architecture, Jolfa International Branch, Islamic Azad University (Iran, Islamic Republic of)], email: Azami@iauj.ac.ir; Sadeghi, Alireza [Department of Architecture, Azarshahr Branch, Islamic Azad University (Iran, Islamic Republic of)], email: irsesta@yahoo.com

    2011-07-01

    As the years pass, the importance of energy sustainability has been increasingly felt and emphasised. This paper presents a study of the construction methods used in Iran to build kohuls (a sort of underground barn) and the lessons to be learnt from them. The study was done in the villages of Benakohul, Hilehvar and Samarkhazan in East Azerbaijan province of northwest Iran. Kohuls are usually constructed in places surrounded by mountains. During winter they act as a shelter for animals, whose body heat and respiration keep them warm. In summer, the animals are away and the atmosphere in the kohul, insulated by the mountain, cools off and stays cold, making it an ideal place to store meat. The heat produced by the cattle inside the kohul also functions as a strong adhesive, reinforcing the walls and ceilings and increasing the sustainability and durability of the kohul. If they are unused for a long period, they decay naturally and eventually collapse.

  6. 四种松属植物叶的抗寒抗旱特点研究%Study on Dry Resistance and Cold Resistance of Leaf of Pinus

    Institute of Scientific and Technical Information of China (English)

    倪福太; 李长有; 王占武; 刘强

    2012-01-01

    为了研究松属植物叶片与植物抗寒抗旱特点的关系,以松属(Pinus)两种植物樟子松(Pinus sylvestris var.mongolica Litvin.)和油松(Pinus tabulaeformis Carr.)为主要实验材料,同时,观察黑松(Pinus thunbergii Parl.)和马尾松(Pinus massoniana Lamb.),研究针叶的表皮特征及叶片不同部位的解剖结构.结果表明,松属植物叶表皮外具有发达的角质层,气孔下陷,具有大的孔下室,树脂道发达.这说明松属植物叶具有旱生和寒性植物的形态结构特征.%In order to study the relationship between leaf of Pinus and drought resistance and cold resistance,epidermis characteristic and anatomy construction of needle leaf of two specices plants(Pinus sylvestrisa var.mongolica Litvin.and Pinus tabulaeformis Carr.) in Pinus are observed.The results indicated that the leaf of Pinus plants have some construction of drought resistance and cold resistance.For example:the outside on the surface of leaf is covered with a cuticle and epicuticular waxes,its stomata are stand out of the epidermis with big bore bottom room and so on.

  7. Dry Eye

    Science.gov (United States)

    ... Eye > Facts About Dry Eye Facts About Dry Eye This information was developed by the National Eye ... the best person to answer specific questions. Dry Eye Defined What is dry eye? Dry eye occurs ...

  8. Changes of seasonally dry forest in the Colombian Patía Valley during the early and middle Holocene and the development of a dry climatic record for the northernmost Andes

    NARCIS (Netherlands)

    Z. González-Carranza; J.C. Berrío; H. Hooghiemstra; J.F. Duivenvoorden; H. Behling

    2008-01-01

    A 450 cm long sediment core was collected from a swamp in the dry forest ecosystem of the Patía Valley in Colombia (02°02′ N, 77° W at 750 m elevation). This core (Potrerillo-2) was analysed using pollen, lithostratigraphy and radiocarbon dates and was correlated with an already existing dataset fro

  9. Déficit de polinização da aceroleira no período seco no semiárido paraibano Pollination deficit of acerola orchards during the dry season in the semiarid region of northeastern Brazil

    Directory of Open Access Journals (Sweden)

    Rozileudo da Silva Guedes

    2011-06-01

    Full Text Available A aceroleira é uma importante frutífera tropical que pode produzir frutos o ano todo na região semiárida do Nordeste do Brasil, caso seja utilizada a irrigação. Como a aceroleira depende da polinização por abelhas coletoras de óleos florais para apresentar uma produção satisfatória de frutos, este trabalho teve como objetivo avaliar a abundância de polinizadores e o sucesso reprodutivo da cultura no período seco, no semiárido paraibano. Foram registradas quatro espécies de abelhas nativas da tribo Centridini, todas consideradas polinizadoras efetivas da aceroleira, pela frequência nas flores e comportamento: Centris aenea Lepeletier, C. tarsata Smith, C. fuscata Lepeletier e C. trigonoides Lepeletier (Apidae, Centridini. A frequência de visitas às flores foi menor no período seco do que no período chuvoso. A polinização cruzada manual complementar resultou em incremento de 61 a 74% na produção de frutos durante o período seco, nos dois anos avaliados, indicando que há um grande déficit de polinização devido à baixa abundância de abelhas Centris. Esse resultado implica a necessidade de manejo dos polinizadores, especialmente em cultivos irrigados durante o período seco, na região semiárida do Nordeste do Brasil.Acerola or Caribbean cherry is an important tropical fructiferous tree, which produces all over the year in the semiarid region of Northeastern Brazil if orchards are irrigated. As this culture depends on the pollination by oil-collecting bees to get a good production, the availability of pollinators, the reproductive success and the possibility of pollination deficit of Malpighia emarginata were studied during the dry season in a site of Paraiba State. Four species of native Centridini bees were observed and considered efficient pollinators due to their frequency and behavior on flowers: Centris aenea Lepeletier, C. tarsata Smith, C. fuscata Lepeletier e C. trigonoides Lepeletier (Apidae, Centridini. The

  10. Characterization (environmental Signature) and Function of the Main Instrumented (monitoring Water Quality Network in Real Time) Rivers Atoyac and Zahuapan in High Atoyac Basin; in Dry, Rain and Winter Season 2013-2014; Puebla-Tlaxcala Mexico

    Science.gov (United States)

    Tavera, E. M.; Rodriguez-Espinosa, P. F.; Morales-Garcia, S. S.; Muñoz-Sevilla, N. P.

    2014-12-01

    The Zahuapan and Atoyac rivers were characterized in the Upper Atoyac through the integration of physical and chemical parameters (environmental firm) determining the behavior and function of the basin as a tool for measuring and monitoring the quality and management of water resources of the water in one of the most polluted rivers in Mexico. For the determination of the environmental signature proceeded to characterize the water through 11 physicochemical parameters: temperature (T), potential hydrogen (pH), dissolved oxygen (DO), spectral absorption coefficient (SAC), the reduction of oxide potential (ORP), turbidity (Turb), conductivity (l), biochemical oxygen demand in 5 days (BOD5), chemical oxygen demand (COD), total suspended solids (TSS) and total dissolved solids (TDS ), which were evaluated in 49 sites in the dry season, 47 for the rainy season and 23 for the winter season in the basin and Atoyac Zahuapan Alto Atoyac, Puebla-Tlaxcala, Mexico river; finding a mathematical algorithm to assimilate and better represent the information obtained. The algorithm allows us to estimate correlation greater than 0.85. The results allow us to propose the algorithm used in the monitoring stations for purposes of processing information assimilated form.This measurement and monitoring of water quality supports the project, the monitoring network in real time and the actions to clean up Atoyac River, in the urban area of the city of Puebla.

  11. Soil dehydrogenase in a land degradation-rehabilitation gradient: observations from a savanna site with a wet/dry seasonal cycle

    OpenAIRE

    Doi, Ryoichi; Ranamukhaarachchi, Senaratne Leelananda

    2013-01-01

    Soil dehydrogenase activity is a good indicator of overall microbial activity in soil, and it can serve as a good indicator of soil condition. However, seasonal changes in soil moisture content may have an effect on soil dehydrogenase activity, making an accurate assessment of soil condition difficult. In this study, we attempted to determine the significance of soil dehydrogenase activity for assessing soil condition, and we attempted to find a way to account for the influence of soil moistu...

  12. Seasonal controls on snow distribution and aerial ablation at the snow-patch and landscape scales, McMurdo Dry Valleys, Antarctica

    OpenAIRE

    Eveland, J. W.; M. N. Gooseff; Lampkin, D. J.; Barrett, J E; Takacs-Vesbach, C. D.

    2013-01-01

    Accumulated snow in the McMurdo Dry Valleys, while limited, has great ecological significance to subnivian soil environments. Though sublimation dominates the ablation process in this region, measurable increases in soil moisture and insulation from temperature extremes provide more favorable conditions with respect to subnivian soil communities. While precipitation is not substantial, significant amounts of snow can accumulate, via wind transport, in topographic lees along the valley bottoms...

  13. Effects of spring season solar drying process on sanitation indicators in sewage sludge and potential as a method for fertilizer production.

    Science.gov (United States)

    Sypuła, Małgorzata; Paluszak, Zbigniew; Ligocka, Anna; Skowron, Krzysztof

    2013-01-01

    The agricultural use of sewage sludge is possible on condition of maintaining microbiological and parasitological standards, and one of the most modern methods improving its sanitary state is solar drying. In the presented study, the effect of this process on the elimination of indicator microorganisms (Escherichia coli, Salmonella Senftenberg W775, Enterococcus spp.) and eggs of Ascaris suum introduced into the biomass of sludge was examined. The experiment was carried out in the spring period with a maximal temperature of 18 °C inside the drying plant. Bacteria and parasite eggs were introduced into special carriers (cylinders filled with sewage sludge) and placed at selected points of the drier. The carriers were removed every 7 days and subject to a research procedure in order to estimate the number of bacteria and percentage of live eggs of Ascaris suum. Sanitization of the material was not obtained, since after 28 days of the process the final product contained a large concentration of Enterococcus spp. and S. Senftenberg W775 (10(5) -10(9) MPNg(-1)). Only the number of E. coli decreased by 6 log. During the process, the fastest decrease in the number of bacteria was observed in E. coli (ca 0.2 log/day), slower in enterococci (0.02-0.081 log/day), and the slowest in bacilli of the genus Salmonella (0.011-0.061 log/day). Sludge after drying also still contained 57-66% of live eggs of A. suum. The study proved that the solar drying of sludge in the spring period results in a product which poses a hazard for public and animal health and environmental sustainability, and should not be used as a fertilizer.

  14. Wintering in the Beginning of Cold Season: Ecofeminist Deconstruction of Nature in West and East in Farrokhzad’s “Let us Believe in the Oncoming of Cold Season”

    Directory of Open Access Journals (Sweden)

    Bahar Mehrabi

    2015-07-01

    Full Text Available Ecofeminists seek the reversal of the oppressing binary oppositions of nature/culture, woman/man as to reach a balanced ecosystem in which women are not considered inferior since they are associated with nature .Therefore, ecofeminism could be regarded as a suitable framework for the discussion of the literary works and their treatment of woman/nature theme. The present article would be an attempt to demonstrate the way  Farrokhzad’s “Let us Believe in the Oncoming of Cold Season” and Plath’s “Wintering”, concern such association and deconstruct the binary oppositions in a way that similarly both women personas are ultimately able to take the role of female artist. Both women transgress the winter and hope for the spring to come, while the winter they pass through differs since it originates from different social backgrounds. As such, new historicism would be applied to discover this difference, since the study is a comparative one and yields to the investigation of different societies in which the poems were composed. Farrokhzad lives in an era on the verge of modernism, that’s why she is still preoccupied with the traditions of the past, though she would finally depict the woman persona as having stepped beyond these limitations. Plath’s concerns, on the other hand, rise from a mind entangled with the impacts of modernity and the hollow men. Both are able to pass the winter, though, as female creators who await the reproductive spring blossoms to flourish.

  15. Runoff characteristics in flood and dry seasons based on wavelet analysis in the source regions of the Yangtze and Yellow rivers%基于小波分析的江河源区汛期和枯水期径流特征

    Institute of Scientific and Technical Information of China (English)

    BING Longfei; SHAO Quanqin; LIU Jiyuan

    2012-01-01

    @@%By decomposing and reconstructing the runoff information from 1965 to 2007 of the hydrologic stations of Tuotuo River and Zhimenda in the source region of the Yangtze River,and Jimai and Tangnaihai in the source region of the Yellow River with db3 wavelet,runoff of different hydrologic stations tends to be declining in the seasons of spring flood,summer flood and dry ones except for that in Tuotuo River.The declining flood/dry seasons series was summer > spring > dry; while runoff of Tuotuo River was always increasing in different stages from 1965 to 2007 with a higher increase rate in summer flood seasons than that in spring ones.Complex Morlet wavelet was selected to detect runoff periodicity of the four hydrologic stations mentioned above.Over all seasons the periodicity was 11-12 years in the source region of the Yellow River.For the source region of the Yangtze River the periodicity was 4-6 years in the spring flood seasons and 13-14 years in the summer flood seasons.The differences of variations of flow periodicity between the upper catchment areas of the Yellow River and the Yangtze River and between seasons were considered in relation to glacial melt and annual snowfall and rainfall as providers of water for runoff.

  16. Common Cold

    Science.gov (United States)

    ... nose, coughing - everyone knows the symptoms of the common cold. It is probably the most common illness. In the course of a year, people ... avoid colds. There is no cure for the common cold. For relief, try Getting plenty of rest ...