Rugged, Portable Tungsten Coil Atomic Emission Spectrometer

Tungsten coil atomic emission spectrometry is an ideal technique for field applications because of its simplicity, low cost, low power requirement, and independence from cooling systems. A new, portable, compact design is reported here. The tungsten coil is extracted from an inexpensive 24 V, 250 W commercial light bulb. The coil is housed in a small, aluminum cell. The emission signal exits from a small aperture in the cell, while the bulk of the blackbody emission from the tungsten coil is blocked. The resulting spectra exhibit extremely low background signals. The atomization cell, a single lens, and a hand-held charge coupled device (CCD) spectrometer are fixed on a 1 x 6 x 30 cm ceramic base. The resulting system is robust and easily transported. A programmable, miniature 400 W solid-state constant current power supply controls the temperature of the coil. Fifteen elements are determined with the system (Ba, Cs, Li, Rb, Cr, Sr, Eu, Yb, Mn, Fe, Cu, Mg, V, Al, and Ga). The precision ranges from 4.3% to 8.4% relative standard deviation for repetitive measurements of the same solution. Detection limits are in the 0.04 to 1500 mu g/L range. Accuracy is tested using standard reference materials for polluted water, peach leaves, and tomato leaves. For those elements present above the detection limit, recoveries range from 72% to 147%.

Antennal malformations in light ocelli drones of Apis mellifera (Hymenoptera, Apidae)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Discopatia cervical no cão: tratamento cirúrgico através de fenestração ventral. Estudo retrospectivo (1986-1997)

Aproximadamente, 15% das discopatias em cães acometem a região cervical, sendo a dor o principal sinal clínico. Descreve-se a ocorrência de protrusão de disco cervical em 17 cães, agrupados segundo a raça, sexo, peso, idade, assim como a distribuição quanto à duração dos sintomas, acometimento dos discos intervertebrais (DIV), tempo de recuperação e porcentagem de sucesso, em relação à condição neurológica presente antes da cirurgia. A raça Dachshund representou 29,5% (n=5), cães sem raça definida, Poodle e Cocker Spaniel Inglês, 17,6% cada (n=9), Pinscher, 11,8% (n=2) e Dálmata, 5,9% (n=1). Destes, 58,8% eram machos (n=10) e 41,2%, fêmeas (n=7), com peso entre 2 e 29kg, e idade média igual a 5,8 anos. O quadro neurológico desses animais correspondia à dor e ataxia, com exceção de um cão Dálmata, 11 anos de idade, que apresentava tetraparesia. A duração dos sinais variou de 2 a 90 dias. Os DIV mais acometidos foram C2/3 (40%), C3/4 (25%), C4/5 (15%), C5/6 (10%) e C6/7 (10%), sendo que alguns animais apresentavam lesões múltiplas. O procedimento foi padrão para todos os animais, através da fenestração e curetagem de todos os DIV abordados pelo acesso ventral, ou seja, de C2/3 até C6/7, empregando-se para isso instrumental usado para remoção de tártaro dentário (curetas Gracey, curetas McCall, extratores de tártaro S.S.White e McCall). O tempo médio de recuperação foi de 9 a 38 dias, sendo que 100% deles recuperaram totalmente as funções neurológicas. Conclui-se que a fenestração ventral apresenta excelentes resultados no tratamento das discopatias cervicais, desde que bem selecionados os pacientes, inclusive, com respeito aos diagnósticos diferenciais.

Aurotriquia adquirida em um canino da raça schnauzer

Alterações adquiridas na coloração da pelagem de cães são raras. Schnauzers miniaturas podem apresentar desenvolvimento idiopático de coloração dourada do pelame, primariamente do tronco, chamada de aurotriquia. O presente trabalho relata a ocorrência de aurotriquia em um cão da raça schnauzer, de três anos de idade, sendo esse o primeiro relato de caso de aurotriquia em schnauzer no Brasil. Por se tratar de alteração de rara ocorrência, torna-se necessária maior atenção a características raciais e um melhor exame físico e anamnese, mesmo se tratando de alteração considerada meramente de fenótipo, pois existem as alterações de coloração bem piores, ligadas a doenças de prognóstico.

Capacidade de retenção de barreiras de proteção produzidas com solo arenoso estabilizado quimicamente

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Evidence for a respiratory component, similar to mammalian respiratory sinus arrhythmia, in the heart rate variability signal from the rattlesnake, Crotalus durissus terrificus

Autonomic control of heart rate variability and the central location of vagal preganglionic neurones (VPN) were examined in the rattlesnake ( Crotalus durissus terrificus), in order to determine whether respiratory sinus arrhythmia (RSA) occurred in a similar manner to that described for mammals. Resting ECG signals were recorded in undisturbed snakes using miniature datalogging devices, and the presence of oscillations in heart rate (f(H)) was assessed by power spectral analysis (PSA). This mathematical technique provides a graphical output that enables the estimation of cardiac autonomic control by measuring periodic changes in the heart beat interval. At fH above 19 min(-1) spectra were mainly characterised by low frequency components, reflecting mainly adrenergic tonus on the heart. By contrast, at f(H) below 19 min(-1) spectra typically contained high frequency components, demonstrated to be cholinergic in origin. Snakes with a f(H) > 19 min(-1) may therefore have insufficient cholinergic tonus and/or too high an adrenergic tonus acting upon the heart for respiratory sinus arrhythmia ( RSA) to develop. A parallel study monitored f(Hd) simultaneously with the intraperitoneal pressures associated with lung inflation. Snakes with a fH < 19 min(-1) exhibited a high frequency (HF) peak in the power spectrum, which correlated with ventilation rate (f(V)). Adrenergic blockade by propranolol infusion increased the variability of the ventilation cycle, and the oscillatory component of the f(H) spectrum broadened accordingly. Infusion of atropine to effect cholinergic blockade abolished this HF component, confirming a role for vagal control of the heart in matching f(H) and f(V) in the rattlesnake. A neuroanatomical study of the brainstem revealed two locations for vagal preganglionic neurones (VPN). This is consistent with the suggestion that generation of ventilatory components in the heart rate variability (HRV) signal are dependent on spatially distinct loci for cardiac VPN. Therefore, this study has demonstrated the presence of RSA in the HRV signal and a dual location for VPN in the rattlesnake. We suggest there to be a causal relationship between these two observations.

Differentiation of the honey bee (Apis mellifera L.) antennal lobes during metamorphosis: a comparative study among castes and sexes

In insects the antennal lobes (AL) constitute the brain deutocerebrum. In bees they consist of two neuropil regions, each associated with one antenna, delimited by a layer of glial cells and somata of neurons. The neuropil is organized in distinct globular structures of dense synaptic axons coming from the olfactory organs of the antennae, known as glomeruli. In Apis mellifera, as in other eusocial species of bees, queens, workers, and drones perform different functions in the colony and consequently the organs associated with these functions undergo a differential development. In this paper we analyzed the structure and size of the differentiating AL of queens, workers, and drones during metamorphosis using light microscopy. During metamorphosis the neuropil enlarge and differentiates into concentric structures known as glomeruli. The results showed size, structural and temporal differences in the glomeruli development among the classes of individuals of the colony. The neuropil differentiation starts early and is faster in drones and newly emerged worker is the colony individual class with greater neuropil area in AL. These results are discussed taking in account the functions of the individuals in the colony. (C) Koninklijke Brill NV, Leiden, 2011.

Structural refinement, optical and microwave dielectric properties of BaZrO3

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

msechBari, a new MITE-like element in Drosophila sechellia related to the Bari transposon

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Differences in the number of sensilla coeloconica and sensilla ampullacea of segment 10 of the antennae of Africanized and Caucasian bees and of their F1 hybrids

The numbers of sensilla coeloconica and sensilla ampullacea of segment 10 of the antennae of Caucasian and Africanized worker bees and of their hybrids were counted with the aid of a scanning electron microscope. Africanized bees have fewer sensilla than Caucasian bees and the continuous distribution obtained from the F1 values suggests polygenic inheritance for the control of this trait. There are also indications that the hybrid Brazilian Apis mellifera studied here are close to typical African bees (Apis mellifera scutellata) in terms of number of sensilla.

Is the number of antennal plate organs (sensilla placodea) greater in hygienic than in non-hygienic Africanized honey bees?

Hygienic behavior is a desirable trait in honey bees (Apis mellifera L.), as hygienic bees quickly remove diseased brood, intermpting the infectious cycle. Hygienic lines of honey bees appear to be more sensitive to the odors of dead and diseased honey bee brood, and Africanized honey bees are generally more hygienic than are European honey bees. We compared the number of sensilla placodea, antennal sensory structures involved in the perception of odor, in 10 bees from each of six hygienic and four non-hygienic colonies of Africanized honey bees. The sensilla placodea of three of the terminal segments (flagellomeres) of the right antenna of each bee were counted with a scanning electron microscope. There were no significant differences in the mean numbers of sensilla placodea between the hygienic and non-hygienic bees, though the variance was higher in the hygienic group. Flagellomere 4 had significantly more sensilla placodea than flagellomeres 6 and 8. However, there was no significant difference between the other two flagellomeres. As hygienic bees are capable of identifying dead, injured, or infested brood inside a capped brood cell, sensilla placodea probably have an important role in enabling worker bees to sense sick brood. However, we did not find greater numbers of this sensory structure in the antennae of hygienic, compared to non-hygienic Africanized honey bees.

Electroantennographic responses of Heterotermes tenuis (Isoptera: Rhinotermitidae) to synthetic (3Z,6Z,8E)-Dodecatrien-1-ol

The subterranean termite Heterotermes tenuis (Isoptera: Rhinotermitidae) is a pest of great importance for the Brazilian economy as it causes serious damages in commercial reforestations of Eucalyptus spp. and sugarcane cultures. (3Z,6Z,8E)-Dodecatrien-1-ol has been identified as a pheromone of some species of subterranean termites. The objective of this research was to synthesize (3Z,6Z,8E)-dodecatrien-1-ol and determine by electroantennographic (EAG) bioassays the selectivity and sensitivity of H. tenius antennae to its whole worker extract and to the synthetic triene alcohol.

Modelagem em tempo real do erro sistemático das observáveis GPS devido à ionosfera

Single frequency GPS receivers have been many used in GPS surveys. Among the several applications, one can mention those that are to obtain the receiver's antenna coordinates in real time. One of the main error sources to these applications is the ionosphere systematic error. In the FCT/UNESP a regional ionosphere model (Mod_Ion) was developed. It has been implemented to execute after collecting of GPS data. At real time application two improvements in the Mod_Ion were introduced, consisting of an alteration of the function of modeling and implementation of the Kalman Filter. The results of the experiments showed that the modifications were the most effective in the ionosphere systematic effect's corrections, providing a improvement in the accuracy of point positioning, of 90,75%, in period of the highest ionosphere activity.

GPS ambiguity resolution and validation under multipath effects: Improvements using wavelets

Integer carrier phase ambiguity resolution is the key to rapid and high-precision global navigation satellite system (GNSS) positioning and navigation. As important as the integer ambiguity estimation, it is the validation of the solution, because, even when one uses an optimal, or close to optimal, integer ambiguity estimator, unacceptable integer solution can still be obtained. This can happen, for example, when the data are degraded by multipath effects, which affect the real-valued float ambiguity solution, conducting to an incorrect integer (fixed) ambiguity solution. Thus, it is important to use a statistic test that has a correct theoretical and probabilistic base, which has became possible by using the Ratio Test Integer Aperture (RTIA) estimator. The properties and underlying concept of this statistic test are shortly described. An experiment was performed using data with and without multipath. Reflector objects were placed surrounding the receiver antenna aiming to cause multipath. A method based on multiresolution analysis by wavelet transform is used to reduce the multipath of the GPS double difference (DDs) observations. So, the objective of this paper is to compare the ambiguity resolution and validation using data from these two situations: data with multipath and with multipath reduced by wavelets. Additionally, the accuracy of the estimated coordinates is also assessed by comparing with the ground truth coordinates, which were estimated using data without multipath effects. The success and fail probabilities of the RTIA were, in general, coherent and showed the efficiency and the reliability of this statistic test. After multipath mitigation, ambiguity resolution becomes more reliable and the coordinates more precise. © Springer-Verlag Berlin Heidelberg 2007.

An effective wavelet method to detect and mitigate low-frequency multipath effects

To ensure high accuracy results from GPS relative positioning, the multipath effects have to be mitigated. Although the careful selection of antenna site and the use of especial antennas and receivers can minimize multipath, it cannot always be eliminated and frequently the residual multipath disturbance remains as the major error in GPS results. The high-frequency multipath from large delays can be attenuated by double difference (DD) denoising methods. But the low-frequency multipath from short delays is very difficult to be reduced or modeled. In this paper, it is proposed a method based on wavelet regression (WR), which can effectively detect and reduce the low-frequency multipath. The wavelet technique is firstly applied to decompose the DD residuals into the low-frequency bias and high-frequency noise components. The extracted bias components by WR are then directly applied to the DD observations to correct them from the trend. The remaining terms, largely characterized by the high-frequency measurement noise, are expected to give the best linear unbiased solutions from a least-squares (LS) adjustment. An experiment was carried out using objects placed close to the receiver antenna to cause, mainly, low-frequency multipath. The data were collected for two days to verify the multipath repeatability. The ground truth coordinates were computed with data collected in the absence of the reflector objects. The coordinates and ambiguity solution were compared with and without the multipath mitigation using WR. After mitigating the multipath, ambiguity resolution became more reliable and the coordinates were more accurate.