The origin ofhigh hydraulic resistance for filter cakes ofdef ormable particles: cell-bed deformation or surface-layer effect?

This study reports a numerical approach for modeling the hydraulic resistance ofa filter cake ofdef ormable cells. First, a mechanical and osmotic model that describes the volume fraction ofsolids in a bed ofyeast cells as a function ofthe compressive pressure it experiences is presented. The effects ofpressure on the compressibility ofyeast cells beds were further investigated both by filtration experiments and by centrifugal experiments based on the multiple speed equilibrium sediment height technique. When comparing the latter measurements with compression model calculations, we observed that the method based on centrifugal experiments suffers from rapid relaxation of the compressed bed. Concerning the filtration experiments, specific resistance ofwell-defined bed ofcells were calculated by a combination of the compression model with a formulation for hydraulic resistivity developed using the Lattice Boltzmann method. We further explain the experimental values observed for the hydraulic resistance ofcell beds, assuming that the first layer ofcells in contact with the membrane partially blocks the membrane area open to flow. In such a case, the blocked area seems to be a constant fraction of the normal cell–cell contact area

Lunar laser ranging in infrfared at hte Grasse laser station

For many years, lunar laser ranging (LLR) observations using a green wavelength have suffered an inhomogeneity problem both temporally and spatially. This paper reports on the implementation of a new infrared detection at the Grasse LLR station and describes how infrared telemetry improves this situation. Our first results show that infrared detection permits us to densify the observations and allows measurements during the new and the full Moon periods. The link budget improvement leads to homogeneous telemetric measurements on each lunar retro-reflector. Finally, a surprising result is obtained on the Lunokhod 2 array which attains the same efficiency as Lunokhod 1 with an infrared laser link, although those two targets exhibit a differential efficiency of six with a green laser link

In vivo magnetic resonance spectroscopy in the brain of Cdkl5 null mice reveals a metabolic profile indicative of mitochondrial dysfunctions

Mutations in the X‐linked CDKL5 gene cause CDKL5 deficiency disorder (CDD), a severe neurodevelopmental condition mainly characterized by infantile epileptic encephalopathy, intellectual disability, and autistic features. The molecular mechanisms underlying the clinical symptoms remain largely unknown and the identification of reliable biomarkers in animal models will certainly contribute to increase our comprehension of CDD as well as to assess the efficacy of therapeutic strategies. Here, we used different Magnetic Resonance (MR) methods to disclose structural, functional, or metabolic signatures of Cdkl5 deficiency in the brain of adult mice. We found that loss of Cdkl5 does not cause cerebral atrophy but affects distinct brain areas, particularly the hippocampus. By in vivo proton‐MR spectroscopy (MRS), we revealed in the Cdkl5 null brain a metabolic dysregulation indicative of mitochondrial dysfunctions. Accordingly, we unveiled a significant reduction in ATP levels and a decrease in the expression of complex IV of mitochondrial electron transport chain. Conversely, the number of mitochondria appeared preserved. Importantly, we reported a significant defect in the activation of one of the major regulators of cellular energy balance, the adenosine monophosphate‐activated protein kinase (AMPK), that might contribute to the observed metabolic impairment and become an interesting therapeutic target for future preclinical trials. In conclusion, MRS revealed in the Cdkl5 null brain the presence of a metabolic dysregulation suggestive of a mitochondrial dysfunction that permitted to foster our comprehension of Cdkl5 deficiency and brought our interest towards targeting mitochondria as therapeutic strategy for CDD

Control of Panicum maximum in sugar cane with preemergence herbicides

Avaliou-se a eficácia dos herbicidas imazapic, imazapyr e pendimethalin, aplicados em pré-ernergência na cultura da cana-de-açúcar, para controle de capim-colonião (Panicum maximum Jacq.).O trabalho foi realizado na Usina São Carlos, Jaboticabal-SP, em solo de classe textural argilosa. O delineamento experimental utilizado foi o de blocos ao acaso com quatro repetições. Os tratamentos foram: imazapic (73,5 e 98 g/ha), imazapyr (122 e 147 g/ha), imazapic+pendimethalin (50+ 1000 e 60+ 1200 g/ha) e pendimethalin (1200 g/ha), além das testemunhas capinada e sem capinas. Para aplicação dos herbicidas foi utilizado um pulverizador costal, à pressão constante (mantida por ar comprimido) de 2,8 kg/cm-, com bicos de jato plano ("leque") DG 11002 e consumo de calda equivalente a 250 l/ha. A variedade de cana-de-açúcar utilizada foi a RB 72454, 3°corte. Tanto o imazapic como o imazapyr proporcionaram resultados considerados muito pobres no controle de P maximum. A mistura de imazapic + pendimethalin apresentou excelente desempenho no controle desta espécie, podendo ser utilizada na menor dose testada. O pendimethalin isolado (1200 g/ha) foi levemente inferior às misturas, mas com resultados ainda considerados muito bons, podendo também ser recomendado para a cultura.The major problem with the sugar cane crop is weed competition, specially Panicum maximum Jacq., which is a very agressive plant. The trial was carried out at Usina São Carlos (a sugar will), in Jaboticabal-SP, during 1998/1999 aiming to study imazapyr and imazapic herbicides, sprayed alone in preemergence, or imazapic in mixture with pendimethalin, for P maximum control. The experimental design was a randomized block with nine treatments and four replications. The treatments were: controls (with and without weeds), imazapic (73.5 and 98 g/ha), imazapyr (122 and 147 g/ha): imazapic+pendimethalin (50+ 1000 and 60+ 1200 g/ha) and pendimethalin (1200 g/ha) at preemergence. The herbicides were applied with a manual sprayer, with constant pressure of 2.8 kg/crrf and jet nozzles with descontinuous deposition (DG11002), using 250 Ilha of the herbicide solution. The sugar-cane variety used was RB 72454. The best preemergence weed control was observed with imazapic+pendimethalim in ali treatments 126 days after application. The postemergence treatment cannot be used because they caused high crop toxicity. The herbicide mixture (imazapic+pendimethalin) showed low efficiency in ali tested treatments

Purple nutsedge (Cyperus rotundus L.) control in sugar-cane crop with imazapic herbicide, isolated or in mixture whith pendimethalin

Visando avaliar nova alternativa para o controle químico da tiririca (Cyperus rotundus) na cultura da cana-de-açúcar (Saccharum spp.), foi conduzido um experimento, em campo, na Usina São Carlos, Jaboticabal-SP, com o herbicida imazapic. aplicado isolado e em mistura no tanque com pendimethalin. em pré-emergência. O mesmo também foi testado. adicionado de surfatante. em pós emergência das plantas cultivada e daninha. Os tratamentos testados foram: imazapic (73,5 . <)8.0 , 122,5 e 147,0 g/ha) e imazapic+pendimethalin (50+1000, 60+1200 e 70+1400 g/ha), em pré-ernergência. Em pós-emergência, o imazapic (73,5 , 98,0 , 125,0 e 147,0 g/ha) foi adicionado de surfatante a 0,15% do produto comercial para o volume de calda. O delineamento experimental utilizado foi o de blocos ao acaso, com quatro repetições. Para a aplicação foi utilizado um pulverizador costal, à pressão constante de 2,8 kg/cm- (mantida por ar comprimido) bicos de jato plano e deposição descontínua (tipo "leque") XR 11002. O consumo de calda foi equivalente a 250 Ilha. A variedade de cana-deaçúcar utilizada foi a RB 855536. A maior dose de imazapic (147,0 g/ha) proporcionou, em pré emergência, os melhores resultados, com 96% de controle, aos 27 dias após o tratamento (DAA). Manteve boa percentagem (72%) de controle até 91 DAA. As misturas de imazapic + pendimethalin não foram eficazes para o controle da tiririca. O herbicida imazapic, aplicado em pós-emergência, apresentou fitotoxidade irreversível nas plantas de cana-de-açúcar (var. RB 855536) e controlou aproximadamente 85% das plantas de tiririca. The major problem with the sugar cane crop is weed competition, especially purple nutsedge which is a very agressive plant. The trial was carried out at Usina São Carlos (a sugar mill), Jaboticabal-Sl', during the summer period (1999/2000) aiming to study the effect of imazapic herbicide on purple nutsedge control, sprayed at pre and postemergence, alone or in mixture with pendimethalin. The experimental design was randomized blocks with thirteen treatments and four replications. The treatments were: controls (with and without weeds), imazapic herbicide (13.5,98.0, 122.5 and 147.0 g/ha), imazapic + pendimethalin (50+ I000, 60+ 1200, 70+ 1400 g/ha), in preemergence application. Postemergence treatments were imazapic, at the same doses, with surfactant 0.15% v/v. The herbicide was applied with a manual sprayer, with a constant pressure of 2,8 kg/cm- and jet nozzles with descontinuous deposition (XR II 002), using the equivalent of 250 Ilha of the herbicide solution. The sugar cane variety used was RB 855536. The best pre-emergence weed control (96%) was observed with 147 g/ha of ~mazapic at 27 days afte~ appl~cation .. The P?stemergence applications cannot be used because they caused high toxicity 111 the culture. The herbicide mixture (imazapic+pendimethalin) showed low efficacy for ali tested treatments

Event-based Asynchronous Sparse Convolutional Networks

Event cameras are bio-inspired sensors that respond to per-pixel brightness changes in the form of asynchronous and sparse "events". Recently, pattern recognition algorithms, such as learning-based methods, have made significant progress with event cameras by converting events into synchronous dense, image-like representations and applying traditional machine learning methods developed for standard cameras. However, these approaches discard the spatial and temporal sparsity inherent in event data at the cost of higher computational complexity and latency. In this work, we present a general framework for converting models trained on synchronous image-like event representations into asynchronous models with identical output, thus directly leveraging the intrinsic asynchronous and sparse nature of the event data. We show both theoretically and experimentally that this drastically reduces the computational complexity and latency of high-capacity, synchronous neural networks without sacrificing accuracy. In addition, our framework has several desirable characteristics: (i) it exploits spatio-temporal sparsity of events explicitly, (ii) it is agnostic to the event representation, network architecture, and task, and (iii) it does not require any train-time change, since it is compatible with the standard neural networks' training process. We thoroughly validate the proposed framework on two computer vision tasks: object detection and object recognition. In these tasks, we reduce the computational complexity up to 20 times with respect to high-latency neural networks. At the same time, we outperform state-of-the-art asynchronous approaches up to 24% in prediction accuracy

Influência do momento da chuva na eficácia do herbicida glifosate, em diferentes concentrações, no inverno e no verão

Two field assays were carried out aiming to evaluate the rain effects on the glyphosate herbicide activity, applied at different concentrations, under two growing seasons (winter and summer). The experiments were conducted at the FCAV / UNESP Experimental Station, during 2000/01. The winter experiment was installed from June to August of 2000 and the summer one was installed from January to March of 2001. The treatments were glyphosate (0,5; 1,0; 2,0 e 4,0%), used as check treatment. In the field, all the trials were set up in the randomized block experimental design, with four replications. The experimental plots was 3.0 m wide x 3.5 m long in the winter assays. In the summer one, the plots' size was 3.0 m x 4.0 m. The treatments were arranged in factorial designs 5 x 4 factors, with five periods between the herbicide spraying and the rain incidence and four concentrations. The herbicide treatments were applied through a back spraying, with six nozzles DG 11002 spaced by 0.5 m, at 30 p.s.i. constant pressions. The artificial rain was provided by a top irrigation system raining 18 - 19 mm during one hour. The artificial rain reduced the glyphosate action, mainly in the shorter periods. Raising the glyphosate concentration to 2.0% supressed the problems promoted by the rain, one hour after sprayings, under winter conditions. Similar results were observed raising the glyphosate concentration to 1.0%, under summer conditions.Com o objetivo de estudar a influência da chuva sobre a eficácia de diferentes concentrações do herbicida glifosate em duas épocas do ano foram instalados dois experimentos. O de inverno foi realizado no período de julho a agosto de 2000 e o de verão, de janeiro a março de 2001. Utilizou-se o delineamento experimental de blocos ao acaso, com quatro repetições, com os tratamentos dispostos em esquema fatorial (4 X 5) + 1, sendo constituído por quatro concentrações de glifosate SAqC (360 g.L-1 de eq. ac.) (0,5; 1,0; 2,0 e 4,0%) na calda de pulverização, correspondendo as doses crescentes de 360, 720, 1440 e 2880 g.ha de eq.ac., cinco intervalos sem chuva após a aplicação. (1, 2, 4, 6 e > 48 horas) e uma testemunha sem herbicida. A unidade experimental foi constituída por uma parcela 3,0 X 3,5 no inverno e 3,0 X 4,0 metros no verão. Os tratamentos foram aplicados em pós-emergência das plantas daninhas, utilizando-se um pulverizador costal, à pressão constante (mantida por ar comprimido) de 30 lbf/pol2, munido de barra com seis bicos DG 11002, espaçados de 0,5 m. Tanto no inverno como no verão foi simulada uma chuva de aproximadamente 20 mm em 60 minutos com o auxílio de um sistema de irrigação por aspersão. Nas duas épocas, a ocorrência da chuva foi prejudicial à ação do glifosate, principalmente nos menores intervalos sem chuva após a aplicação. Para proporcionar controle semelhante ao tratamento com intervalo de 48 horas sem chuva após a aplicação, no inverno, a concentração do herbicida na calda de 2,0% v/v (1440 g. ha-1 de eq. ac. De glifosate) exigiu intervalo de pelo menos duas horas sem chuva após a aplicação. No verão, para alcançar o mesmo nível de controle foi necessário um período de pelo menos uma hora sem chuva após a aplicação, para a mesma dose de glifosate, e com a concentração do herbicida na calda de 1% v/v (720 g. ha-1 de eq. ac. de glifosate) obteve-se resultado satisfatório com período superior a duas horas sem chuva após a aplicação

Stronger diversity effects with increased environmental stress : a study of multitrophic interactions between oak, powdery mildew and ladybirds

Recent research has suggested that increasing neighbourhood tree species diversity may mitigate the impact of pests or pathogens by supporting the activities of their natural enemies and/or reducing the density of available hosts. In this study, we attempted to assess these mechanisms in a multitrophic study system of young oak (Quercus), oak powdery mildew (PM, caused by Erysiphe spp.) and a mycophagous ladybird (Psyllobora vigintiduo-punctata). We assessed ladybird mycophagy on oak PM in function of different neighbourhood tree species compositions. We also evaluated whether these species interactions were modulated by environmental conditions as suggested by the Stress Gradient Hypothesis. We adopted a complementary approach of a field experiment where we monitored oak saplings subjected to a reduced rainfall gradient in a young planted forest consisting of different tree species mixtures, as well as a lab experiment where we independently evaluated the effect of different watering treatments on PM infections and ladybird mycophagy. In the field experiment, we found effects of neighbourhood tree species richness on ladybird mycophagy becoming more positive as the target trees received less water. This effect was only found as weather conditions grew drier. In the lab experiment, we found a preference of ladybirds to graze on infected leaves from trees that received less water. We discuss potential mechanisms that might explain this preference, such as emissions of volatile leaf chemicals. Our results are in line with the expectations of the Natural Enemies Hypothesis and support the hypothesis that biodiversity effects become stronger with increased environmental stress

Breeding amphibians in captivity

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73877/1/j.1748-1090.1977.tb00864.x.pd