scholarly journals Surface-Floating Pupal Exuviae of Chironomidae (Diptera) in Urban Streams: is There a Best Time of Day to Sample Them?

2016 ◽  
Vol 9 (2) ◽  
pp. 101-107
Author(s):  
Herick Soares Santana ◽  
Vanessa Araújo Lima ◽  
Juliana Simião-Ferreira
Keyword(s):  
Local Community ◽  
Adult Emergence ◽  
Time Of Day ◽  
Dry Season ◽  
Urban Streams ◽  
Environmental Condition ◽  
Taxonomic Richness ◽  
Pupal Exuviae ◽  
First Order ◽  
First Time

Abstract. The use of pupal exuviae is a method that allows evaluating the environmental condition using information provided by the diversity of Chironomidae. The exuviae can disperse over distances up to 100 m from where the adults emerged, allowing perform detailed studies on the local community. The aim of this study was verify whether there are differences in the taxonomic richness and abundance in the emergence of pupal exuviae of Chironomidae during different periods of day in three urban Cerrado streams. The samples were taken in the dry season of July 2011, in three first-order streams located nearby Anápolis municipality, Goiás State, Brazil, using drift nets for a period ranging from 8 to 20 h, with removal and replacement of the drift nets every two hours period. 6.129 exuviae were collected in the three streams and the Onconeura and Polypedilum generatotaled 70% of all individuals collected. The time at 16 h was the most representative of the number of exuviae collected, while the first time (8 h) had the lowest amount of exuviae. The genera richness and abundance of exuviae did not show changes according to the time of day on the streams, indicating that there is not a period in which there is a greater frequency of adult emergence of Chironomidae.Exúvias de Pupa de Chironomidae (Diptera) em Riachos Urbanos de Cerrado: existe um Melhor Horário do Dia para Amostrar?Resumo. O uso de exúvias de pupa é um método que permite avaliar condições ambientais utilizando informações da diversidade de Chironomidae. Exúvias de pupas podem se dispersar em distâncias de até 100 m dos locais onde os adultos emergiram, permitindo realizar estudos sobre a comunidade local. O objetivo deste estudo foi verificar se existem diferenças na riqueza taxonômica e abundância em exúvias surgidas de pupa de Chironomidae durante diferentes períodos do dia em córregos urbanos do Bioma Cerrado. As amostras foram coletadas na estação seca de julho de 2011, em três riachos de primeira ordem localizados próximos à cidade de Anápolis, Goiás, Brasil, utilizando redes de deriva por um período que variou de 8-20 h, com remoção e substituição das redes a cada duas horas. Foram coletadas 6129 exúvias nos três córregos e os gêneros Onconeura e Polypedilum totalizaram 70% de todos os indivíduos coletados. O horário de 16 h foi o mais representativo em relação ao número de exuvias coletadas, enquanto que as exúvias coletadas às 8 h foram menos abundantes. A riqueza e a abundância de gêneros de exúvias não apresentaram mudanças de acordo com o horário do dia nos córregos estudados, indicando que não existe um período no qual há uma maior frequência de aparecimento de Chironomidae adulto.

scholarly journals Non-Linear First-Order Differential Boundary Problems with Multipoint and Integral Conditions

2021 ◽  
Vol 5 (1) ◽  
pp. 15
Author(s):  
Misir J. Mardanov ◽  
Yagub A. Sharifov ◽  
Yusif S. Gasimov ◽  
Carlo Cattani
Keyword(s):  
Integral Equation ◽  
Integral Boundary Conditions ◽  
Contraction Mapping Principle ◽  
Boundary Problems ◽  
Integral Boundary ◽  
Multipoint Problem ◽  
First Order ◽  
Banach Contraction ◽  
First Time ◽  
Banach Contraction Mapping Principle

This paper considers boundary value problem (BVP) for nonlinear first-order differential problems with multipoint and integral boundary conditions. A suitable Green function was constructed for the first time in order to reduce this problem into a corresponding integral equation. So that by using the Banach contraction mapping principle (BCMP) and Schaefer’s fixed point theorem (SFPT) on the integral equation, we can show that the solution of the multipoint problem exists and it is unique.

The kinetics of the decarboxylation of β-resorcylic acid in catechol

1976 ◽  
Vol 29 (2) ◽  
pp. 443 ◽  
Author(s):  
MA Haleem ◽  
MA Hakeem
Keyword(s):  
Rate Equation ◽  
Kinetic Data ◽  
Reaction Rate ◽  
Complex Mechanism ◽  
First Order ◽  
Absolute Reaction Rate ◽  
First Time ◽  
Kinetics Of ◽  
Absolute Reaction ◽  
Reaction Rate Equation

Kinetic data are reported for the decarboxylation of β-resorcylic acid in resorcinol and catechol for the first time. The reaction is first order. The observation supports the view that the decomposition proceeds through an intermediate complex mechanism. The parameters of the absolute reaction rate equation are calculated.

scholarly journals Description of the larva of Bromeliagrion rehni (Odonata: Coenagrionidae) with bionomic notes concerning its phytotelmic habitat in central Amazonas, Brazil

2008 ◽  
Vol 25 (3) ◽  
pp. 479-486 ◽  
Author(s):  
Sharlene R. da S. Torreias ◽  
Ulisses G. Neiss ◽  
Neusa Hamada ◽  
Ruth L. Ferreira-Keppler ◽  
Frederico A.A. Lencioni
Keyword(s):  
Rainy Season ◽  
Environmental Parameters ◽  
Dry Season ◽  
Stage Larva ◽  
Water Volume ◽  
Apical Region ◽  
Last Stage ◽  
First Time ◽  
The Relationship

The last-stage larva of Bromeliagrion rehni Garrison in De Marmels & Garrison, 2005 is described and illustrated and bionomics and habitat information on this species are provided. The study was conducted in the Reserva Florestal Adolpho Ducke, located near Manaus, state of Amazonas, Brazil.Twelve samplings were done between April, 2003 and April, 2005: six in the rainy season and six in the dry season. In each sampling month, 12 bromeliads (Guzmania brasiliensis Ule, 1907, Bromeliaceae) were collected, six of which were terrestrial and six epiphytic, yielding144 samples. A total of 75 specimens of B. rehni were collected. The relationship between larval B. rehni abundance and the measured environmental parameters (volume (ml), pH, season and stratum) was significant (ANCOVA, F = 5.296, d.f. = 130, p < 0.001). Larvae were most abundant in the rainy season (p < 0.01) and water volume was positively related to the abundance of B. rehni. Larvae of B. rehni can be distinguished from those of B. fernandezianum (the only species in the genus with described larvae) by the number of setae in the prementum and by the color of the apical region of the femur. The association of this species with phytotelmata of G. brasiliensis is reported here for the first time.

scholarly journals Estimating population and livestock density of mobile pastoralists and sedentary settlements in the south-eastern Lake Chad area

2015 ◽  
Vol 10 (1) ◽  
Author(s):  
Vreni Jean-Richard ◽  
Lisa Crump ◽  
Abbani Alhadj Abicho ◽  
Ali Abba Abakar ◽  
Abdraman Mahamat II ◽  
...  
Keyword(s):  
Land Use ◽  
Population Density ◽  
Small Ruminants ◽  
Dry Season ◽  
Land Use Management ◽  
Lake Chad ◽  
Mobile Pastoralists ◽  
Livestock Density ◽  
Density Dynamics ◽  
First Time

Mobile pastoralists provide major contributions to the gross domestic product in Chad, but little information is available regarding their demography. The Lake Chad area population is increasing, resulting in competition for scarce land and water resources. For the first time, the density of people and animals from mobile and sedentary populations was assessed using randomly defined sampling areas. Four sampling rounds were conducted over two years in the same areas to show population density dynamics. We identified 42 villages of sedentary communities in the sampling zones; 11 (in 2010) and 16 (in 2011) mobile pastoralist camps at the beginning of the dry season and 34 (in 2011) and 30 (in 2012) camps at the end of the dry season. A mean of 64.0 people per km2 (95% confidence interval, 20.3-107.8) were estimated to live in sedentary villages. In the mobile communities, we found 5.9 people per km2 at the beginning and 17.5 people per km2 at the end of the dry season. We recorded per km2 on average 21.0 cattle and 31.6 small ruminants in the sedentary villages and 66.1 cattle and 102.5 small ruminants in the mobile communities, which amounts to a mean of 86.6 tropical livestock units during the dry season. These numbers exceed, by up to five times, the published carrying capacities for similar Sahelian zones. Our results underline the need for a new institutional framework. Improved land use management must equally consider the needs of mobile communities and sedentary populations.

scholarly journals Quantum Gravity at the Corner

Universe ◽  
2018 ◽  
Vol 4 (10) ◽  
pp. 107 ◽  
Author(s):  
Laurent Freidel ◽  
Alejandro Perez
Keyword(s):  
Quantum Gravity ◽  
Symplectic Form ◽  
Direct Application ◽  
Quantum Geometry ◽  
Quantum Level ◽  
Gravitational System ◽  
Gauge Transformations ◽  
First Order ◽  
Conformal Field ◽  
First Time

We investigate the quantum geometry of a 2d surface S bounding the Cauchy slices of a 4d gravitational system. We investigate in detail for the first time the boundary symplectic current that naturally arises in the first-order formulation of general relativity in terms of the Ashtekar–Barbero connection. This current is proportional to the simplest quadratic form constructed out of the pull back to S of the triad field. We show that the would-be-gauge degrees of freedo arising from S U ( 2 ) gauge transformations plus diffeomorphisms tangent to the boundary are entirely described by the boundary 2-dimensional symplectic form, and give rise to a representation at each point of S of S L ( 2 , R ) × S U ( 2 ) . Independently of the connection with gravity, this system is very simple and rich at the quantum level, with possible connections with conformal field theory in 2d. A direct application of the quantum theory is modelling of the black horizons in quantum gravity.

scholarly journals Measurements of hydrogen cyanide (HCN) and acetylene (C<sub>2</sub>H<sub>2</sub>) from the Infrared Atmospheric Sounding Interferometer (IASI)

2013 ◽  
Vol 6 (4) ◽  
pp. 917-925 ◽  
Author(s):  
V. Duflot ◽  
D. Hurtmans ◽  
L. Clarisse ◽  
Y. R'honi ◽  
C. Vigouroux ◽  
...  
Keyword(s):  
Fourier Transform ◽  
Hydrogen Cyanide ◽  
Atmospheric Transport ◽  
Trace Gases ◽  
First Order ◽  
Line Mixing ◽  
Atmospheric Sounding ◽  
First Time ◽  
Order Comparison ◽  
Emission Ratios

Abstract. Hydrogen cyanide (HCN) and acetylene (C2H2) are ubiquitous atmospheric trace gases with medium lifetime, which are frequently used as indicators of combustion sources and as tracers for atmospheric transport and chemistry. Because of their weak infrared absorption, overlapped by the CO2 Q branch near 720 cm−1, nadir sounders have up to now failed to measure these gases routinely. Taking into account CO2 line mixing, we provide for the first time extensive measurements of HCN and C2H2 total columns at Reunion Island (21° S, 55° E) and Jungfraujoch (46° N, 8° E) in 2009–2010 using observations from the Infrared Atmospheric Sounding Interferometer (IASI). A first order comparison with local ground-based Fourier transform infraRed (FTIR) measurements has been carried out allowing tests of seasonal consistency which is reasonably captured, except for HCN at Jungfraujoch. The IASI data shows a greater tendency to high C2H2 values. We also examine a nonspecific biomass burning plume over austral Africa and show that the emission ratios with respect to CO agree with previously reported values.

Factors affecting the phenology of the first brood of the sugar-cane froghopper Aeneolamia varia saccharina (Dist.) (Homoptera, Cercopidae) in Trinidad

1975 ◽  
Vol 65 (3) ◽  
pp. 359-372 ◽  
Author(s):  
A. B. S. King
Keyword(s):  
Adult Emergence ◽  
Dry Season ◽  
Soil Conditions ◽  
Factors Affecting ◽  
Expected Time ◽  
Short Period ◽  
Incubation Periods ◽  
Close Relationship ◽  
Dry Soil ◽  
Predictive Relationship

AbstractThe size and occurrence of the first brood of adults of Aeneolamia varia saccharina (Dist.) are examined in relation to the pattern of egg eclosion and rainfall. The proportion of eggs hatching within a month of oviposition in the laboratory (short-period eggs) decreased from over 90% in August to less than 20% in January, but the incubation periods of the remaining, long-period eggs were longest in those laid during October and November. The overall hatching distributions tended to be bimodal with most eggs hatching during the early months of the year under moist conditions at 26°C. Dry soil conditions delay eclosion, and eggs obtained from fields during the dry season and then incubated under moist conditions tended to hatch at the normally expected time of the first rains in May. The numbers of eggs expected to produce the first brood, computed from laboratory hatching data and estimates of the numbers and fecundities of froghoppers during the second, third and fourth broods, were less than the actual numbers sampled just before the first rains. There was a close relationship between the first rainfall of over one inch within 48 h and adult emergence 27 and 34 days later, and 85% of field egg populations in May had hatched and/or died by the week after the first rains. However some variation in the date of their occurrence accounted for non-synchrony of first broods over the region. The numbers of diapause eggs in fields sampled during the dry season failed to give a good predictive relationship with first brood adult populations, probably because of density dependent mortality of eggs or hatchling nymphs.

scholarly journals Aquatic oligochaetes associated with bryophytes in an Atlantic Forest stream

2013 ◽  
Vol 13 (4) ◽  
pp. 371-375 ◽  
Author(s):  
Luciana Falci Theza Rodrigues ◽  
Lucas Deziderio Santana ◽  
Roberto da Gama Alves
Keyword(s):  
Water Flow ◽  
Atlantic Forest ◽  
Benthic Macroinvertebrates ◽  
Dry Season ◽  
Forest Fragment ◽  
Order Stream ◽  
First Order ◽  
Aquatic Oligochaetes ◽  
Forest Stream ◽  
Dry And Rainy Seasons

There are few reports in the literature about the colonization of benthic macroinvertebrates on bryophytes. The aim of the present study was to analyzed the oligochaetes established on bryophytes adhered to stones in a first-order stream. The collections were carried out in an Atlantic Forest fragment area during the dry and rainy seasons. We identified 15 taxa from a total of 422 oligochaetes specimens, of which the most abundant were Pristina sp.1, Enchytraeidae and Pristina jenkinae. Unlike other habitats, where the abundance of macroinvertebrates tends to be greater in the dry season, we did not find any significant differences in the abundance, richness, composition and diversity between the two periods. The results of this study indicate that bryophytes are possible areas of refuge for oligochaetes in periods of faster water flow.

scholarly journals Chironomid (Diptera) species recorded from UK lakes as pupal exuviae

2013 ◽  
Vol 45 (2) ◽  
pp. 13 ◽  
Author(s):  
L.P. Ruse
Keyword(s):  
Water Surface ◽  
New Records ◽  
Adult Emergence ◽  
Chemical Characteristics ◽  
Aquatic Species ◽  
Pupal Exuviae ◽  
Water Currents ◽  
Chironomid Species ◽  
Juvenile Stages ◽  
Physical And Chemical

An inventory of chironomid species (Diptera, Chironomidae) data collected from 221 lake basins or reservoirs is detailed together with major physical and chemical characteristics of these waterbodies. Aquatic species of Chironomidae must rise to the water surface for adult emergence. Floating exuviae are transported by wind and water currents to lakeshores. Species data were obtained by collecting lake marginal floating pupal exuviae representing juvenile stages dwelling from across the lake. Among the 450 species found, several were new records for the British Isles.

scholarly journals Generation of over 1000 Diffraction Spots from 2D Graded Photonic Super-Crystals

Photonics ◽  
2020 ◽  
Vol 7 (2) ◽  
pp. 27
Author(s):  
Safaa Hassan ◽  
Yan Jiang ◽  
Khadijah Alnasser ◽  
Noah Hurley ◽  
Hualiang Zhang ◽  
...  
Keyword(s):  
Diffraction Pattern ◽  
Cell Size ◽  
Lattice Constant ◽  
Field Intensity ◽  
Lattice Model ◽  
Dual Lattice ◽  
First Order ◽  
Super Cell ◽  
First Time ◽  
Fractional Orders

For the first time, we are able to generate over 1000 diffraction spots from a graded photonic super-crystal with a unit super-cell size of 12a × 12a where a is the lattice constant and hole radii are gradually changed in dual directions. The diffraction pattern from the graded photonic super-crystal reveals unique diffraction properties. The first order diffractions of (±1,0) or (0,±1) disappear. Fractional diffraction orders are observed in the diffraction pattern inside a square with vertices of (1,1), (1,−1), (−1,−1) and (−1,−1). The fractional diffraction can be understood from lattices with a period of a. However, a dual-lattice model is considered in order to explain higher-order diffractions. E-field intensity simulations show a coupling and re-distribution among fractional orders of Bloch waves. There are a total of 12 × 12 spots in E-field intensity in the unit supercell corresponding to 12 × 12 fractional diffraction orders in the diffraction pattern and 12 × 12 fractional orders of momentum in the first Brillouin zone in k-space.

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