Dispersal of aphids, whiteflies and their natural enemies under photoselective nets

Integrated Pest Management of insects includes several control tactics, such as the use of photoselective nets, which may reduce the flight activity of insects. Limiting the dispersal of pests such as aphids and whiteflies is important because of their major role as vectors of plant viruses, while a minor impact on natural enemies is desired. In this study, we examined for the first time the dispersal ability of three vector species, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae), Macrosiphum euphorbiae (Thomas) (Hemiptera: Aphididae) and Myzus persicae (Sulzer) (Hemiptera: Aphididae), in cages covered with photoselective nets. Contrary to the results obtained with aphids, the ability of the whitefly B. tabaci, to reach the target plant was reduced by photoselective nets. In a second set of experiments, the impact of UV-absorbing nets on the visual cues of two important predator species, Orius laevigatus (Fieber) (Hemiptera: Anthocoridae) and Amblyseius swirskii Athias-Henriot (Acari: Phytoseiidae), was evaluated. The anthocorid was caught in higher numbers in traps placed under regular nets, whereas the mites preferably chose environments in which the UV radiation was attenuated. We have observed a wide range of effects that impedes generalization, although photoselective nets have a positive effect on pest management of whiteflies and aphids under protected environments.

Conservation of endangered Lupinus mariae-josephae in its natural habitat by inoculation with selected, native Bradyrhizobium strains

Lupinus mariae-josephae is a recently discovered endemism that is only found in alkaline-limed soils, a unique habitat for lupines, from a small area in Valencia region (Spain). In these soils, L. mariae-josephae grows in just a few defined patches, and previous conservation efforts directed towards controlled plant reproduction have been unsuccessful. We have previously shown that L. mariae-josephae plants establish a specific root nodule symbiosis with bradyrhizobia present in those soils, and we reasoned that the paucity of these bacteria in soils might contribute to the lack of success in reproducing plants for conservation purposes. Greenhouse experiments using L. mariae-josephae trap-plants showed the absence or near absence of L. mariae-josephae-nodulating bacteria in ‘‘terra rossa’’ soils of Valencia outside of L. mariaejosephae plant patches, and in other ‘‘terra rossa’’ or alkaline red soils of the Iberian Peninsula and Balearic Islands outside of the Valencia L. mariae-josephae endemism region. Among the bradyrhizobia able to establish an efficient symbiosis with L. mariae-josephae plants, two strains, LmjC and LmjM3 were selected as inoculum for seed coating. Two planting experiments were carried out in consecutive years under natural conditions in areas with edapho-climatic characteristics identical to those sustaining natural L. mariae-josephae populations, and successful reproduction of the plant was achieved. Interestingly, the successful reproductive cycle was absolutely dependent on seedling inoculation with effective bradyrhizobia, and optimal performance was observed in plants inoculated with LmjC, a strain that had previously shown the most efficient behavior under controlled conditions. Our results define conditions for L. mariae-josephae conservation and for extension to alkaline-limed soil habitats, where no other known lupine can thrive.

Autonomous Acquisition of Natural Situated Communication

An important part of human intelligence, both historically and operationally, is our ability to communicate. We learn how to communicate, and maintain our communicative skills, in a society of communicators – a highly effective way to reach and maintain proficiency in this complex skill. Principles that might allow artificial agents to learn language this way are in completely known at present – the multi-dimensional nature of socio-communicative skills are beyond every machine learning framework so far proposed. Our work begins to address the challenge of proposing a way for observation-based machine learning of natural language and communication. Our framework can learn complex communicative skills with minimal up-front knowledge. The system learns by incrementally producing predictive models of causal relationships in observed data, guided by goal-inference and reasoning using forward-inverse models. We present results from two experiments where our S1 agent learns human communication by observing two humans interacting in a realtime TV-style interview, using multimodal communicative gesture and situated language to talk about recycling of various materials and objects. S1 can learn multimodal complex language and multimodal communicative acts, a vocabulary of 100 words forming natural sentences with relatively complex sentence structure, including manual deictic reference and anaphora. S1 is seeded only with high-level information about goals of the interviewer and interviewee, and a small ontology; no grammar or other information is provided to S1 a priori. The agent learns the pragmatics, semantics, and syntax of complex utterances spoken and gestures from scratch, by observing the humans compare and contrast the cost and pollution related to recycling aluminum cans, glass bottles, newspaper, plastic, and wood. After 20 hours of observation S1 can perform an unscripted TV interview with a human, in the same style, without making mistakes.

Autonomous Acquisition of Natural Language

An important part of human intelligence is the ability to use language. Humans learn how to use language in a society of language users, which is probably the most effective way to learn a language from the ground up. Principles that might allow an artificial agents to learn language this way are not known at present. Here we present a framework which begins to address this challenge. Our auto-catalytic, endogenous, reflective architecture (AERA) supports the creation of agents that can learn natural language by observation. We present results from two experiments where our S1 agent learns human communication by observing two humans interacting in a realtime mock television interview, using gesture and situated language. Results show that S1 can learn multimodal complex language and multimodal communicative acts, using a vocabulary of 100 words with numerous sentence formats, by observing unscripted interaction between the humans, with no grammar being provided to it a priori, and only high-level information about the format of the human interaction in the form of high-level goals of the interviewer and interviewee and a small ontology. The agent learns both the pragmatics, semantics, and syntax of complex sentences spoken by the human subjects on the topic of recycling of objects such as aluminum cans, glass bottles, plastic, and wood, as well as use of manual deictic reference and anaphora.

New experiments on speaker diarization for unsupervised speaking style voice building for speech synthesis

El uso universal de síntesis de voz en diferentes aplicaciones requeriría un desarrollo sencillo de las nuevas voces con poca intervención manual. Teniendo en cuenta la cantidad de datos multimedia disponibles en Internet y los medios de comunicación, un objetivo interesante es el desarrollo de herramientas y métodos para construir automáticamente las voces de estilo de varios de ellos. En un trabajo anterior se esbozó una metodología para la construcción de este tipo de herramientas, y se presentaron experimentos preliminares con una base de datos multiestilo. En este artículo investigamos más a fondo esta tarea y proponemos varias mejoras basadas en la selección del número apropiado de hablantes iniciales, el uso o no de filtros de reducción de ruido, el uso de la F0 y el uso de un algoritmo de detección de música. Hemos demostrado que el mejor sistema usando un algoritmo de detección de música disminuye el error de precisión 22,36% relativo para el conjunto de desarrollo y 39,64% relativo para el montaje de ensayo en comparación con el sistema base, sin degradar el factor de mérito. La precisión media para el conjunto de prueba es 90.62% desde 76.18% para los reportajes de 99,93% para los informes meteorológicos.

Protocolos de diseño y cálculo de luz natural en arquitectura

Esta tesis doctoral aborda el problema de la falta de un protocolo que conecte las elevadas y variadas expectativas formales que plantea la arquitectura singular respecto de la luz natural con las distintas herramientas de cálculo y sus métricas asociadas disponibles. La pregunta que la tesis responde es la siguiente “¿Es posible definir un protocolo que ordene las decisiones de diseño y cálculo en la resolución de los problemas de luz natural en la arquitectura singular en forma de procesos, de modo suficientemente genérico y operativo, creando conocimiento útil sobre el problema de que se trate en cada etapa del mismo?” Metodológicamente se desarrolla en dos ciclos de investigación enlazados: primero se DEFINE de modo científico el protocolo y luego se EVALÚA SU APLICABILIDAD. La construcción del protocolo se resuelve utilizando el método inductivo a partir de un corpus previo de problemas de luz natural ya resueltos por el autor. Son analizados de modo sistemático y aplicando diversas estrategias de reducción y síntesis. conducen a un enunciado inicial del protocolo. Una vez enunciado el protocolo, que se denomina DAYLIGHTING CANVAS, se valora su la aplicabilidad mediante experimentación directa, que se realiza a través de tres experiencias diferentes. En la primera evaluamos su aplicabilidad en un problema representativo, en la segunda su aplicabilidad para resolución de problemas planteados de modo aleatorio, y por último su aplicabilidad en el caso de ser empleado por diferentes autores. ABSTRACT The Ph.D. thesis address the lack of a protocol capable to link the higher expectations regarding daylighting of the singular architecture practice with the available daylighting calculation tools and metrics. The thesis question is as follows: “Is it possible to define a protocol capable to arrange the design and calculation decisions needed to be made to solve a daylighting problem for a singular architecture project, as a process, in a way as generic as operational, by building daylighting related knowledge in each step of it?” Methodologically the research is developed in two linked stages: first the protocol is scientifically DEFINED and then its APPLICABILITY is tested. The protocol is built up by using the inductive method over a group of previously solved daylighting projects provided by the thesis author. Those projects has been systematically analyzed by applying some reduction and synthesis strategies, which leads to a preliminary protocol formulation. Once the protocol is fully formulated under the name of “DAYLIGHTING CANVAS”, its applicability is assessed by direct experimentation, done through three different experiments. In the first one the applicability to a complex problem is assessed; in the second one its applicability to non predicted daylighting problems; and finally its applicability for different users.

Natural trans-splicing in carnitine octanoyltransferase pre-mRNAs in rat liver

Carnitine octanoyltransferase (COT) transports medium-chain fatty acids through the peroxisome. During isolation of a COT clone from a rat liver library, a cDNA in which exon 2 was repeated, was characterized. Reverse transcription-PCR amplifications of total RNAs from rat liver showed a three-band pattern. Sequencing of the fragments revealed that, in addition to the canonical exon organization, previously reported [Choi, S. J. et al. (1995) Biochim. Biophys. Acta 1264, 215–222], there were two other forms in which exon 2 or exons 2 and 3 were repeated. The possibility of this exonic repetition in the COT gene was ruled out by genomic Southern blot. To study the gene expression, we analyzed RNA transcripts by Northern blot after RNase H digestion of total RNA. Three different transcripts were observed. Splicing experiments also were carried out in vitro with different constructs that contain exon 2 plus the 5′ or the 3′ adjacent intron sequences. Our results indicate that accurate joining of two exons 2 occurs by a trans-splicing mechanism, confirming the potential of these structures for this process in nature. The trans-splicing can be explained by the presence of three exon-enhancer sequences in exon 2. Analysis by Western blot of the COT proteins by using specific antibodies showed that two proteins corresponding to the expected Mr are present in rat peroxisomes. This is the first time that a natural trans-splicing reaction has been demonstrated in mammalian cells.

Zeta potential in intact natural sandstones at elevated temperatures

Supporting data are included in PDF and CSV files; any additional data may be obtained from the corresponding author (e-mail: j.vinogradov@imperial.ac.uk). TOTAL is thanked for partial support of Jackson's Chair in Geological Fluid Mechanics and for supporting the activities of the TOTAL Laboratory for Reservoir Physics at Imperial College London where these experiments were conducted. The Editor thanks Andre Revil and Paul Glover for their assistance in evaluating this paper.

Requirement for natural killer T (NKT) cells in the induction of allograft tolerance

In this study, we investigated the role of Vα14 natural killer T (NKT) cells in transplant immunity. The ability to reject allografts was not significantly different between wild-type (WT) and Vα14 NKT cell-deficient mice. However, in models in which tolerance was induced against cardiac allografts by blockade of lymphocyte function-associated antigen-1/intercellular adhesion molecule-1 or CD28/B7 interactions, long-term acceptance of the grafts was observed only in WT but not Vα14 NKT cell-deficient mice. Adoptive transfer with Vα14 NKT cells restored long-term acceptance of allografts in Vα14 NKT cell-deficient mice. The critical role of Vα14 NKT cells to mediate immunosuppression was also observed in vitro in mixed lymphocyte cultures in which lymphocyte function-associated antigen-1/intercellular adhesion molecule-1 or CD28/B7 interactions were blocked. Experiments using IL-4- or IFN-γ-deficient mice suggested a critical contribution of IFN-γ to the Vα14 NKT cell-mediated allograft acceptance in vivo. These results indicate a critical contribution of Vα14 NKT cells to the induction of allograft tolerance and provide a useful model to investigate the regulatory role of Vα14 NKT cells in various immune responses.

What was natural in the coastal oceans?

Humans transformed Western Atlantic coastal marine ecosystems before modern ecological investigations began. Paleoecological, archeological, and historical reconstructions demonstrate incredible losses of large vertebrates and oysters from the entire Atlantic coast. Untold millions of large fishes, sharks, sea turtles, and manatees were removed from the Caribbean in the 17th to 19th centuries. Recent collapses of reef corals and seagrasses are due ultimately to losses of these large consumers as much as to more recent changes in climate, eutrophication, or outbreaks of disease. Overfishing in the 19th century reduced vast beds of oysters in Chesapeake Bay and other estuaries to a few percent of pristine abundances and promoted eutrophication. Mechanized harvesting of bottom fishes like cod set off a series of trophic cascades that eliminated kelp forests and then brought them back again as fishers fished their way down food webs to small invertebrates. Lastly, but most pervasively, mechanized harvesting of the entire continental shelf decimated large, long-lived fishes and destroyed three-dimensional habitats built up by sessile corals, bryozoans, and sponges. The universal pattern of losses demonstrates that no coastal ecosystem is pristine and few wild fisheries are sustainable along the entire Western Atlantic coast. Reconstructions of ecosystems lost only a century or two ago demonstrate attainable goals of establishing large and effective marine reserves if society is willing to pay the costs. Historical reconstructions provide a new scientific framework for manipulative experiments at the ecosystem scale to explore the feasibility and benefits of protection of our living coastal resources.

A natural experiment on plant acclimation: lifetime stomatal frequency response of an individual tree to annual atmospheric CO2 increase.

Carbon dioxide (CO2) has been increasing in atmospheric concentration since the Industrial Revolution. A decreasing number of stomata on leaves of land plants still provides the only morphological evidence that this man-made increase has already affected the biosphere. The current rate of CO2 responsiveness in individual long-lived species cannot be accurately determined from field studies or by controlled-environment experiments. However, the required long-term data sets can be obtained from continuous records of buried leaves from living trees in wetland ecosystems. Fine-resolution analysis of the lifetime leaf record of an individual birch (Betula pendula) indicates a gradual reduction of stomatal frequency as a phenotypic acclimation to CO2 increase. During the past four decades, CO2 increments of 1 part per million by volume resulted in a stomatal density decline of approximately 0.6%. It may be hypothesized that this plastic stomatal frequency response of deciduous tree species has evolved in conjunction with the overall Cenozoic reduction of atmospheric CO2 concentrations.

The natural killer cell receptor Ly-49A recognizes a peptide-induced conformational determinant on its major histocompatibility complex class I ligand.

Natural killer (NK) cells are inhibited from killing cellular targets by major histocompatibility complex (MHC) class I molecules. In the mouse, this can be mediated by the Ly-49A NK cell receptor that specifically binds the H-2Dd MHC class I molecule, then inhibits NK cell activity. Previous experiments have indicated that Ly-49A recognizes the alpha 1/alpha 2 domains of MHC class I and that no specific MHC-bound peptide appeared to be involved. We demonstrate here that alanine-substituted peptides, having only the minimal anchor motifs, stabilized H-2Dd expression and provided resistance to H-2Dd-transfected, transporter associated with processing (TAP)-deficient cells from lysis by Ly-49A+ NK cells. Peptide-induced resistance was blocked only by an mAb that binds a conformational determinant on H-2Dd. Moreover, stabilization of "empty" H-2Dd heavy chains by exogenous beta 2-microglobulin did not confer resistance. In contrast to data for MHC class I-restricted T cells that are specific for peptides displayed MHC molecules, these data indicate that NK cells are specific for a peptide-induced conformational determinant, independent of specific peptide. This fundamental distinction between NK cells and T cells further implies that NK cells are sensitive only to global changes in MHC class I conformation or expression, rather than to specific pathogen-encoded peptides. This is consistent with the "missing self" hypothesis, which postulates that NK cells survey tissues for normal expression of MHC class I.

ATP-dependent uptake of natural product cytotoxic drugs by membrane vesicles establishes MRP as a broad specificity transporter.

MRP is a recently isolated ATP-binding cassette family transporter. We previously reported transfection studies that established that MRP confers multidrug resistance [Kruh, G. D., Chan, A., Myers, K., Gaughan, K., Miki, T. & Aaronson, S. A. (1994) Cancer Res. 54, 1649-1652] and that expression of MRP is associated with enhanced cellular efflux of lipophilic cytotoxic agents [Breuninger, L. M., Paul, S., Gaughan, K., Miki, T., Chan, A., Aaronson, S. A. & Kruh, G. D. (1995) Cancer Res. 55, 5342-5347]. To examine the biochemical mechanism by which MRP confers multidrug resistance, drug uptake experiments were performed using inside-out membrane vesicles prepared from NIH 3T3 cells transfected with an MRP expression vector. ATP-dependent transport was observed for several lipophilic cytotoxic agents including daunorubicin, etoposide, and vincristine, as well as for the glutathione conjugate leukotriene C4 (LTC4). However, only marginally increased uptake was observed for vinblastine and Taxol. Drug uptake was osmotically sensitive and saturable with regard to substrate concentration, with Km values of 6.3 microM, 4.4 microM, 4.2 microM, 35 nM, and 38 microM, for daunorubicin, etoposide, vincristine, LTC4, and ATP, respectively. The broad substrate specificity of MRP was confirmed by the observation that daunorubicin transport was competitively inhibited by reduced and oxidized glutathione, the glutathione conjugates S-(p-azidophenacyl)-glutathione (APA-SG) and S-(2,4-dinitrophenyl)glutathione (DNP-SG), arsenate, and the LTD4 antagonist MK571. This study establishes that MRP pumps unaltered lipophilic cytotoxic drugs, and suggests that this activity is an important mechanism by which the transporter confers multidrug resistance. The present study also indicates that the substrate specificity of MRP is overlapping but distinct from that of P-glycoprotein, and includes both the neutral or mildly cationic natural product cytotoxic drugs and the anionic products of glutathione conjugation. The widespread expression of MRP in tissues, combined with its ability to transport both lipophilic xenobiotics and the products of phase II detoxification, indicates that the transporter represents a widespread and remarkably versatile cellular defense mechanism.

Comparative analysis of ribonuclease P RNA using gene sequences from natural microbial populations reveals tertiary structural elements.

PCR amplification of template DNAs extracted from mixed, naturally occurring microbial populations, using oligonucleotide primers complementary to highly conserved sequences, was used to obtain a large collection of diverse RNase P RNA-encoding genes. An alignment of these sequences was used in a comparative analysis of RNase P RNA secondary and tertiary structure. The new sequences confirm the secondary structure model based on sequences from cultivated organisms (with minor alterations in helices P12 and P18), providing additional support for nearly every base pair. Analysis of sequence covariation using the entire RNase P RNA data set reveals elements of tertiary structure in the RNA; the third nucleotides (underlined) of the GNRA tetraloops L14 and L18 are seen to interact with adjacent Watson-Crick base pairs in helix P8, forming A:G/C or G:A/U base triples. These experiments demonstrate one way in which the enormous diversity of natural microbial populations can be used to elucidate molecular structure through comparative analysis.

Applying reactive models to column experiments to assess the hydrogeochemistry of seawater intrusion: optimising ACUAINTRUSION and selecting cation exchange coefficients with PHREEQC

Three sets of laboratory column experimental results concerning the hydrogeochemistry of seawater intrusion have been modelled using two codes: ACUAINTRUSION (Chemical Engineering Department, University of Alicante) and PHREEQC (U.S.G.S.). These reactive models utilise the hydrodynamic parameters determined using the ACUAINTRUSION TRANSPORT software and fit the chloride breakthrough curves perfectly. The ACUAINTRUSION code was improved, and the instabilities were studied relative to the discretisation. The relative square errors were obtained using different combinations of the spatial and temporal steps: the global error for the total experimental data and the partial error for each element. Good simulations for the three experiments were obtained using the ACUAINTRUSION software with slight variations in the selectivity coefficients for both sediments determined in batch experiments with fresh water. The cation exchange parameters included in ACUAINTRUSION are those reported by the Gapon convention with modified exponents for the Ca/Mg exchange. PHREEQC simulations performed using the Gains-Thomas convention were unsatisfactory, with the exchange coefficients from the database of PHREEQC (or range), but those determined with fresh water – natural sediment allowed only an approximation to be obtained. For the treated sediment, the adjusted exchange coefficients were determined to improve the simulation and are vastly different from those from the database of PHREEQC or batch experiment values; however, these values fall in an order similar to the others determined under dynamic conditions. Different cation concentrations were simulated using two different software packages; this disparity could be attributed to the defined selectivity coefficients that affect the gypsum equilibrium. Consequently, different calculated sulphate concentrations are obtained using each type of software; a smaller mismatch was predicted using ACUAINTRUSION. In general, the presented simulations by ACUAINTRUSION and PHREEQC produced similar results, making predictions consistent with the experimental data. However, the simulated results are not identical to the experimental data; sulphate (total S) is overpredicted by both models, most likely due to such factors as the kinetics of gypsum, the possible variations in the exchange coefficients due to salinity and the neglect of other processes.