Mehiläisten (Apis mellifera) kukkavierailut mansikalla (Fragaria x ananassa) ja vadelmalla (Rubus idaeus) sekä kukkavierailuihin vaikuttavat tekijät

Hyönteispölytys lisää monien ristipölytteisten viljelykasvien siemensatoa sekä parantaa sadon laatua. Marjakasveilla, kuten mansikalla ja vadelmalla marjojen koko suurenee sekä niiden laatu paranee onnistuneen pölytyksen seurauksena. Aiempien havaintojen mukaan mansikan kukat eivät pääsääntöisesti houkuttele mehiläisiä, kun taas vadelma on yksi mehiläisten pääsatokasveista. Tutkimuksen tarkoituksena oli selvittää, miten tehokkaasti mehiläiset vierailevat mansikalla sekä vadelmalla, keskittyen kukkakohtaisiin käynteihin tuntia kohti. Mehiläisiä voidaan käyttää Gliocladium catenulatum-vektoreina torjuttaessa mansikan ja vadelman harmaahometta (Botrytis cinerea). Kukkavierailujen perusteella arvioidaan, onko vektorilevitys riittävän tehokas torjumaan harmaahometta ja miten hyvin mehiläisiä voidaan käyttää pölytyspalveluihin, etenkin mansikalla. Havainnot kerättiin kuudelta eri tilalta Sisä-Savosta kesällä 2007. Kukkavierailuja laskettiin mansikan ja vadelman kukinnan aikana erilaisissa sääolosuhteissa, eri kellonaikoina ja eri etäisyyksillä mehiläispesistä. Kukat valittiin satunnaisesti, ja valintaperusteena oli kukan avonaisuus. Tarkkailuaika riippui mehiläisten lentoaktiivisuudesta. Mansikan koko havaintojakson keskiarvoksi tuli 1,75 käyntiä kukkaa kohti tunnissa. Vadelmalla vastaava luku oli 4,27, joten keskiarvojen perusteella vadelma oli houkuttelevampi kuin mansikka. Kasvukauden vaiheella ei ollut eroja vierailuihin kummallakaan kasvilla, mutta vuorokaudenajan suhteen vierailuja oli enemmän aamupäivällä kuin iltapäivällä. Lämpötila korreloi positiivisesti vierailutiheyden kanssa kummallakin kasvilla. Sääolosuhteet rajoittivat havaintojen keräämistä ja kesä oli erittäin sateinen. Mehiläiset vierailivat kukissa riittävästi haastavissakin sääolosuhteissa niin, että harmaahometorjunta onnistui. Vektorilevitystä suunnitellessa, etenkin mansikalla, tulee ottaa huomioon pesien sijoittelu sekä riittävä lukumäärä. Pesien ravinnontarpeen tulee olla suuri, jotta mehiläiset keräisivät ravintoa kukista mahdollisimman tehokkaasti. Pesiin voidaan lisätä tarvittaessa avosikiöitä tai poistaa siitepölyvarastoja ravinnonkeruuaktiivisuuden lisäämiseksi. Lisätutkimusta tarvitaan pesien sijoittelun, kilpailevien kasvien sekä mansikkalajikkeiden houkuttelevuuden vaikutuksesta vierailutiheyteen. Suomalaisten mansikkalajikkeiden meden sekä siitepölyneritystä olisi myös hyvä selvittää.

Interaction of melittin with endotoxic lipid

Several amphipathic and cationic substances are known to bind lipid A, the toxic component of bacterial lipopolysaccharides. In this report, we have characterized, by fluorescence methods, the interaction of melittin, an amphipathic and basic 26-residue polypeptide isolated from bee venom, with lipid A. The stoichiometry of the complex appears to be two molecules of melittin to one of lipid A with a dissociation constant of 2.5 × 10 −6 M. The binding of melittin not only modifies the endotoxic properties of lipid A in a number of biological assays, but also results in abrogation of the hemolytic activity of melittin. A model of the complex is proposed based on the known structures of lipid A and melittin, and the observed stoichiometry of binding.

Worker piping triggers hissing for coordinated colony defence in the dwarf honeybee Apis florea

Defending a large social insect colony containing several thousands of workers requires the simultaneous action of many individuals. Ideally this action involves communication between the workers, enabling coordinated action and a fast response. The Asian dwarf honeybee, Apis florea, is a small honeybee with an open nesting habit and a comparatively small colony size, features that leave them particularly exposed to predators. We describe here a novel defence response of these bees in which the emission of an initial warning signal from one individual (“piping”) is followed 0.3 to 0.7 seconds later by a general response from a large number of bees (“hissing”). Piping is audible to the human ear, with a fundamental frequency of 384 ± 31Hz and lasting for 0.82 ± 0.35 seconds. Hissing is a broad band, noisy signal, clearly audible to the human observer and produced by slight but visible movements of the bees' wings. Hissing begins in individuals close to the piping bee, spreads rapidly to neighbours and results in an impressive coordinated crescendo occasionally involving the entire colony. Piping and hissing are accompanied by a marked decrease, or even cessation, of worker activities such as forager dancing and departures from the colony. We show that whereas hissing of the colony can be elicited without piping, the sequential and correlated piping and hissing response is specific to the presence of potential predators close to the colony. We suggest that the combined audio-visual effect of the hissing might deter small predators, while the cessation of flight activity could decrease the risk of predation by birds and insects which prey selectively on flying bees.

Swarm intelligence algorithms for integrated optimization of piezoelectric actuator and sensor placement and feedback gains

Swarm intelligence algorithms are applied for optimal control of flexible smart structures bonded with piezoelectric actuators and sensors. The optimal locations of actuators/sensors and feedback gain are obtained by maximizing the energy dissipated by the feedback control system. We provide a mathematical proof that this system is uncontrollable if the actuators and sensors are placed at the nodal points of the mode shapes. The optimal locations of actuators/sensors and feedback gain represent a constrained non-linear optimization problem. This problem is converted to an unconstrained optimization problem by using penalty functions. Two swarm intelligence algorithms, namely, Artificial bee colony (ABC) and glowworm swarm optimization (GSO) algorithms, are considered to obtain the optimal solution. In earlier published research, a cantilever beam with one and two collocated actuator(s)/sensor(s) was considered and the numerical results were obtained by using genetic algorithm and gradient based optimization methods. We consider the same problem and present the results obtained by using the swarm intelligence algorithms ABC and GSO. An extension of this cantilever beam problem with five collocated actuators/sensors is considered and the numerical results obtained by using the ABC and GSO algorithms are presented. The effect of increasing the number of design variables (locations of actuators and sensors and gain) on the optimization process is investigated. It is shown that the ABC and GSO algorithms are robust and are good choices for the optimization of smart structures.

Construction of Equivalent Circuit of a Single and Isolated Transformer Winding From FRA Data Using the ABC Algorithm

This paper reports the results of employing an artificial bee colony search algorithm for synthesizing a mutually coupled lumped-parameter ladder-network representation of a transformer winding, starting from its measured magnitude frequency response. The existing bee colony algorithm is suitably adopted by appropriately defining constraints, inequalities, and bounds to restrict the search space and thereby ensure synthesis of a nearly unique ladder network corresponding to each frequency response. Ensuring near-uniqueness while constructing the reference circuit (i.e., representation of healthy winding) is the objective. Furthermore, the synthesized circuits must exhibit physical realizability. The proposed method is easy to implement, time efficient, and problems associated with the supply of initial guess in existing methods are circumvented. Experimental results are reported on two types of actual, single, and isolated transformer windings (continuous disc and interleaved disc).

Construction of Equivalent Circuit of a Single and Isolated Transformer Winding From FRA Data Using the ABC Algorithm

This paper reports the results of employing an artificial bee colony search algorithm for synthesizing a mutually coupled lumped-parameter ladder-network representation of a transformer winding, starting from its measured magnitude frequency response. The existing bee colony algorithm is suitably adopted by appropriately defining constraints, inequalities, and bounds to restrict the search space and thereby ensure synthesis of a nearly unique ladder network corresponding to each frequency response. Ensuring near-uniqueness while constructing the reference circuit (i.e., representation of healthy winding) is the objective. Furthermore, the synthesized circuits must exhibit physical realizability. The proposed method is easy to implement, time efficient, and problems associated with the supply of initial guess in existing methods are circumvented. Experimental results are reported on two types of actual, single, and isolated transformer windings (continuous disc and interleaved disc).

Quantum chemical study on influence of intermolecular hydrogen bonding on the geometry, the atomic charges and the vibrational dynamics of 2,6-dichlorobenzonitrile

FT-IR (4000-400 cm(-1)) and FT-Raman (4000-200 cm(-1)) spectral measurements on solid 2,6-dichlorobenzonitrile (2,6-DCBN) have been done. The molecular geometry, harmonic vibrational frequencies and bonding features in the ground state have been calculated by density functional theory at the B3LYP/6-311++G (d,p) level. A comparison between the calculated and the experimental results covering the molecular structure has been made. The assignments of the fundamental vibrational modes have been done on the basis of the potential energy distribution (PED). To investigate the influence of intermolecular hydrogen bonding on the geometry, the charge distribution and the vibrational spectrum of 2,6-DCBN; calculations have been done for the monomer as well as the tetramer. The intermolecular interaction energies corrected for basis set superposition error (BSSE) have been calculated using counterpoise method. Based on these results, the correlations between the vibrational modes and the structure of the tetramer have been discussed. Molecular electrostatic potential (MEP) contour map has been plotted in order to predict how different geometries could interact. The Natural Bond Orbital (NBO) analysis has been done for the chemical interpretation of hyperconjugative interactions and electron density transfer between occupied (bonding or lone pair) orbitals to unoccupied (antibonding or Rydberg) orbitals. UV spectrum was measured in methanol solution. The energies and oscillator strengths were calculated by Time Dependent Density Functional Theory (TD-DFT) and matched to the experimental findings. TD-DFT method has also been used for theoretically studying the hydrogen bonding dynamics by monitoring the spectral shifts of some characteristic vibrational modes involved in the formation of hydrogen bonds in the ground and the first excited state. The C-13 nuclear magnetic resonance (NMR) chemical shifts of the molecule were calculated by the Gauge independent atomic orbital (GIAO) method and compared with experimental results. Standard thermodynamic functions have been obtained and changes in thermodynamic properties on going from monomer to tetramer have been presented. (C) 2013 Elsevier B.V. All rights reserved.

Cooperative Communication of UAV to Perform Multi-task Using Nature Inspired Techniques

In this paper, the approach for assigning cooperative communication of Uninhabited Aerial Vehicles (UAV) to perform multiple tasks on multiple targets is posed as a combinatorial optimization problem. The multiple task such as classification, attack and verification of target using UAV is employed using nature inspired techniques such as Artificial Immune System (AIS), Particle Swarm Optimization (PSO) and Virtual Bee Algorithm (VBA). The nature inspired techniques have an advantage over classical combinatorial optimization methods like prohibitive computational complexity to solve this NP-hard problem. Using the algorithms we find the best sequence in which to attack and destroy the targets while minimizing the total distance traveled or the maximum distance traveled by an UAV. The performance analysis of the UAV to classify, attack and verify the target is evaluated using AIS, PSO and VBA.

Dynamic response of a piezoelectric flapping wing

Piezo-composite membranes have advantages over motorized flapping where frequencies are high and certain coupling between bending and twisting is useful to generate lift and forward flight. We draw examples of fruit fly and bumble bee. Wings with Piezo ceramic PZT coating are realized. The passive mechanical response of the wing is characterized experimentally and validated using finite element simulation. Piezoelectric actuation with uniform electrode coating is characterized and optimal frequencies for flapping are identified. The experimental data are used in an empirical model and advanced ratio for a flapping insect like condition for various angular orientations is estimated.

Effect of Nb Content on the Microstructure and Mechanical Properties of Zr-Cu-Ni-Al-Nb Glass Forming Alloys

(Zr65Al10Ni10Cu15)(100-x) Nb-x glass forming alloys with Nb contents ranging from 0 to 15 at.% were prepared by water-cooled copper mould cast. The alloys with different Nb contents exhibited different microstructures and mechanical properties. Unlike the monolithic Zr65Al10Ni10Cu15 bulk metallic glass, only a few primary bee beta-Ti phase dendrites were found to distribute in the glassy matrix of the alloys with x = 5. For alloys with x = 10, more beta-phase dendrites forms, together with quasicrystalline particles densely distributed in the matrix of the alloys. For alloys with x = 15, the microstructure of the alloy is dominated by a high density of fully developed P-phase dendrites and the volume fraction of quasicrystalline particles significantly decreases. Room temperature compression tests showed that the alloys with x = 5 failed at 1793 MPa and exhibited an obvious plastic strain of 3.05%, while the other samples all failed in a brittle manner. The ultimate fracture strengths are 1793, 1975 and 1572 MPa for the alloys with x = 0, 10 and 15 at.% Nb, respectively.

Proceedings of the Twenty-third Annual Symposium on sea turtle biology and conservation, 17 to 21 March 2003, Kuala Lumpur, Malaysia

The 23rd Annual Symposium on Sea Turtle Biology and Conservation was held between 17 and 21 March 2003 at The Legend Hotel in Kuala Lumpur, Malaysia, hosted by the Community Conservation Network, Hawaii, and WWF-Malaysia. The meeting was attended by slightly more than 300 participants representing 73 countries, a dramatic drop in participation from previous years brought about in no small part by the looming war in the middle east region and concerns over travel safety. For 22 years the Symposium had bee an Americas-based event, even though it is the annual gathering of the "international" sea turtle society, and with the move to Malaysia, the Symposium hoped to raise the awareness among the general public of the plight of amrine turtles in Southeast Asia, and share the enormous exspertise of the world authorities on sea turtles with this so-far underrepresented region. Adopting the thems, "Living With Turtles", the Symposium had a very personal flavour, and the smaller number of participants made it possible to make and renew acquaintances, and have time for discussion between sessions. While the travel safety concern excuse was often quoted, it was a pity, particularly to the large contingent of people who attended the event for the first time from underrepresented regions, that many of the household names linked to marine turtle biology and conservation were not present to share their knowledge and promote the global concerns on the plight of turtle populations.

Regulação endócrina de curto prazo de hormônios relacionados à fome em mulheres obesas que apresentam episódios de compulsão alimentar

A compulsão alimentar está associada a diversas doenças, entre elas, a obesidade.Com o intuito de pesquisar a diferença hormonal ligada ao controle da fome e da saciedade associada ao episódio de compulsão alimentar (ECA), avaliou-se a concentração sérica dos hormônios que regulam este processo em mulheres adultas. Métodos: O estudo experimental foi composto de 3 grupos (n=23), sendo: grupo Eutrófico (GE;n=8), grupo obeso sem ECA (GO;n=7) e obesas com ECA (ECA;n=8). Todas as mulheres que participaram do estudo freqüentavam os serviços de saúde da Policlínica Piquet Carneiro. Foram dosados os hormônios: Grelina Total, Glucagon, Adiponectina, Amilina, Peptídeo C, GLP-1, Insulina e Leptina séricos nos tempos: jejum, 15 e 60 minutos após a ingestão da refeição fornecida. As refeições ingeridas foram controladas em energia, 55% carboidratos, 15% proteínas, 30% lipídios. Os dados foram analisados como valores médios por grupo em software SAS, considerando p<0,05. Resultados: A idade das mulheres estudadas variou de 32 a 50 anos. A concentração de adiponectina encontrada, que é inversamente proporcional a adiposidade, foi significativamente menor no grupo ECA em relação aos demais grupos (p=0,01). Em relação à leptina, o grupo GO apresentou concentração maior em relação aos demais grupos (p<0,0001). Já, a concentração de grelina encontrada foi significativamente menor no grupo ECA em relação aos demais grupos (p=0,02). Foram encontradas concentrações significativamente maiores de insulina no grupo GO em relação aos demais grupos (p=0,04). A concentração de amilina encontrada foi significativamente maior no grupo GO em relação aos outros grupos (p=0,01). A concentração de GLP-1 encontrada no grupo GO foi maior em média, porém esta diferença não foi estatisticamente significativa entre os grupos (p=0,25). A concentração de Peptídeo C encontrada no grupo GO foi maior em relação aos outros grupos (p=0,003). Apesar da concentração de Glucagon no grupo ECA ser maior em relação aos demais grupos, estes valores não eram diferentes estatisticamente (p=0,13). Nossos achados mostraram que obesas ECA tem perfil hormonal diferente de obesas sem ECA. A baixa concentração de grelina do grupo de obesas ECA e a alta concentração de insulina, peptídeo C e amilina nas obesas com e sem ECA pode estar relacionado com o aumento da ingestão alimentar e com o desequilíbrio energético.

Proceedings of the international workshop on the ecology and fisheries for tunas associated with floating objects

It has long been known that tunas frequently associate with floating objects, such as trees washed out to sea during periods of heavy rainfall, and fishermen have taken advantage of this behavior to facilitate the capture of fish. In some coastal areas, such as the Philippines, artisanal fishermen construct anchored fish-aggregating devices (FADs) to attract fish. More recently, large numbers of free-floating FADs have been constructed for deployment by large purse seiners on the high seas. The FADs often can be interrogated by the seiner and located at great distances using radio telemetry and/or GPS (Global Positioning System) technologies. In some cases a fleet of fishing vessels has a tender vessel which deploys and maintains the FADs, and notifies the fishing vessels when fish are seen around them. This workshop was convened by the Inter-American Tropical Tuna Commission and sponsored by Bumble Bee Seafoods, Inc., for the purpose of bringing together scientists and fishermen who have studied the association of tunas with floating objects. Special efforts were made to get participants from all the areas in which tunas associated with floating objects are the targets of fisheries. Thus the "regional review papers" include contributions for the eastern Atlantic, the southern Caribbean Sea, the Indian Ocean, and the eastern and western Pacific Oceans. Many of these reviews and other contributed papers are published in this proceedings volume. Other papers discussed in the workshop were published elsewhere; these papers are cited in the list of background documents in the Report of the Workshop.

Avian comparative genomics: reciprocal chromosome painting between domestic chicken (Gallus gallus) and the stone curlew (Burhinus oedicnemus, Charadriiformes) - An atypical species with low diploid number

The chicken is the most extensively studied species in birds and thus constitutes an ideal reference for comparative genomics in birds. Comparative cytogenetic studies indicate that the chicken has retained many chromosome characters of the ancestral avia

Comparison of benthic fauna of two beels under different management system

A comparative study of benthic fauna between Rajdhala beel and Padmai beel of Netrakona District under different management system was carried out from July 1999 to January 20OO. An average number of 1113 and 1175 organisms/m2 were obtained from Rajdhala heel and Padmai beel respectively. A total of 22 taxa belonging to 8 diverse groups, Oligochaetes, Chironomids, Molluscs, Ceratopogonids, Diptera (other than Chironomids and Ceratopogonids), Ephemeroptera, Leeches and Crustaceans were recorded. Oligochaetes were dominated and constituted 46% and 49% ofthe total benthic population in Rajdhala heel and Padmai beel respectively. The next dominant group was the Chironomids, which constituted 31% and 30% of the total benthic population in Rajdhala beel and Padmai beel respectively. The highest number 1279 and 1437 individuals/m2 of benthic fauna was recorded in December from Rajdhla beel and Padmai bee! in respectively. The lowest number of benthic fauna 869 and 914 individuals/m2 were found during September and July from Rajdhala beel and Padmai beel respectively. Monthly variation of benthic fauna among two beels were found statistically significant (p<0.05). The numerical distributions of benthic fauna was found to be varied with depth ranges. However, the depth wise variation of total benthic fauna between two heels was not found statistically significant. Fish yield of Rajdhala beel (488 kg/ha/yr) was appreciably higher than the Padmai beel (250 kg/ha/yr).