Cold acclimation of chill coma mechanisms in the locust CNS

Temperature has profound effects on the neural function and behaviour of insects. When exposed to low temperature, migratory locusts (Locusta migratoria) enter chill coma (neuromuscular paralysis) and can resume normal body functions after returning to normal temperature. Our laboratory has studied phenomena underlying environmental stress-induced comas in locusts and found that they are associated with a sudden loss of K+ homeostasis and also a temporary electrical silence in the central nervous system (CNS). However, the mechanisms underlying chill coma entry and recovery are not well understood, particularly the role of the CNS has not been determined. Here, I investigated neural function during chill coma in the locust by measuring electrical activity in the CNS. As pre-exposure to moderately low temperatures, either chronically (cold acclimation) or acutely (rapid cold hardening; RCH), has been found to improve the insect’s cold tolerance, I also determined cold acclimation and RCH protocols that will improve the locust's cold tolerance and whether these protocols affect neural shutdown during chill coma in the locust. With an implanted thermocouple in the thorax, I determined the temperature associated with a loss of responsiveness (CTmin) in intact male adult locusts. In parallel experiments, I recorded field potential (FP) in the metathoracic ganglion (MTG) in semi-intact preparations to determine the temperature that would induce neural shutdown. I found that acclimation at 10 ˚C and RCH at 4 ˚C reduced chill coma recovery time (CCRT) in intact animal preparations and RCH at 4 ˚C for 4 hours reduced the temperature at neural shutdown in semi-intact preparations. These results suggest that pre-exposure to cold can improve the locust's resistance to chill coma and support the notion that the CNS has a role in determining entry into and exit from chill coma in locusts.

The preparation of a certified reference material of polar pesticides in freeze-dried water (CRM 606)

The preparation of a certified reference material of polar pesticides in freeze-dried water is described. The pesticides selected were atrazine, simazine, carbaryl, propanil, linuron, fenamiphos and permethrin which were added to 6000 litres of tap water at 50–80 μg · L–1 (200–320 μg · L–1 for permethrin) level in presence of NaCl (2.5 g · L–1) prior lyophilization. After the freeze-drying process the residue was rehomogenized, filled into amber glass bottles and stored at –20 °C, +4 °C and +20 °C. All pesticides were determined by HPLC/diode array detector, except permethrin which was determined by GC/ECD. The results obtained for atrazine, simazine, carbaryl, propanil, linuron and fenamiphos showed no within- or between-bottle inhomogeneity, however the material was non-homogeneous for permethrin and therefore this was withdrawn from further studies. With respect to the stability for over one year, all pesticides were stable at –20 °C. At +4 °C all pesticides were stable for at least 9 months and at +20 °C the stability was demonstrated only during the first month of storage. The content (mass fractions) of atrazine, simazine, carbaryl, propanil and linuron in freeze-dried water (CRM 606) was certified by an interlaboratory testing and a certification campaign.

Qualidade da carne de ovinos puros e cruzados criados no Semiárido Nordestino brasileiro.

Resumo: A procura por carne de qualidade tem proporcionado ao setor de ovinocultura a adoção por técnicas de produção que possam contribuir para disponibilizar ao mercado produtos que atendam as necessidades dos consumidores, que se tornam cada vez mais exigentes quanto à aquisição de produtos que possam trazer benefícios a saúde. Assim, objetivou-se determinar a qualidade da carne de ovinos puros e cruzados criados no semiárido Nordestino. Utilizaram-se 30 cordeiros machos e fêmeas, oriundos dos cruzamentos Morada Nova x Morada Nova, Rabo Largo x Morada Nova e Santa Inês x Morada Nova, alojados em baias e alimentados com dieta a base de capim Canarana, milho farelo de soja e calcário. Os animais foram abatidos com peso médio de 24 kg de peso vivo e as carcaças mantidas em câmara frigorífica a 4?C, por 24 horas. Após esse período, foi seccionado o músculo Longissimus dorsi que foi embalado, identificado e armazenado a 20?C. Foram determinados os atributos físicos de capacidade de retenção de água, perda de peso por cocção e força de cisalhamento; os atributos químicos como umidade, proteína, cinza, lipídios e colesterol; avaliações subjetivas da carcaça como cor, marmoreio, textura da carne, distribuição da gordura, espessura da gordura e área de olho de lombo; os sensoriais de dureza, suculência, sabor, aroma e aceitação global e o perfil de ácidos graxos. O delineamento utilizado foi em esquema fatorial 3x2 (três grupos genéticos e dois sexos) e as médias comparadas pelo teste de Duncan a 5%. Não houve diferença (p>0,05) entre os genótipos para a composição química da carne, exceto para a variável lipídio (p<0,05). Para as características subjetivas da carcaça o genótipo influenciou (p<0,05) nas variáveis cor, marmoreio e textura da carne. O genótipo promoveu efeito (p<0,05) para as características físicas de capacidade de retenção de água e perda de peso por cocção. Os atributos sensoriais não sofreram efeitos (p>0,05) dos genótipos avaliados. Os genótipos influenciaram (p<0,05) as concentrações dos ácidos graxos saturados, monoinsaturados e poli-insaturados assim como, nas relações ?3:?6 e AGM:AGS. O fator sexo influenciou (p<0,05) nas variáveis umidade, força de cisalhamento, dureza, ácidos graxos desejáveis e relação ?3:?6. O cruzamento entre raças nativas mostrou-se com potencial para a produção de carne de qualidade, a raça Morada Nova melhorou os atributos físico-químicos da carne e em seu perfil lipídico e, o fator sexo melhorou o atributo maciez dando destaque a carne das fêmeas. Abstract: The demand for quality meat products has given the sheep industry sector productions techniques that can contribute providing the market with products that supply the needs of consumers require, who are becoming more demanding as the acquisition of differentiated and bring health benefits. The objective was to evaluate the quality of the pure sheep meat and cross bred in the semiarid Northeast of Brazil. It was used 30 male lambs and female, that came from crosses Morada Nova x Morada Nova, Rabo Largo x Morada Nova and Santa Ines x Morada Nova, housed in pens and fed a diet of grass Canarana, corn soybean meal and limestone. The animals were slaughtered at average weight of 24 kg, live weight, and carcasses kept in refrigeration chamber at 4 ° C for 24 hours. After this period the Longissimus dorsi muscle was selected, packaged, labeled and stored at 20˚C. The physical attributes were determined such as water holding capacity, cooking weight loss and shear force; the chemical attributes such as moisture, protein, ash, lipids and cholesterol; Subjective evaluations such as color, marbling, meat texture, fat distribution, fat thickness and loin eye area; the hardness sensory, juiciness, flavor, aroma and global acceptance and fatty acid profile. The design was a 3x2 factorial arrangement (three genetic groups and two genders) and the measures compared by Duncan test at 5%. There was no difference (p> 0.05) between genotypes for the chemical composition of meat, except for the lipid variable (p <0.05). To the subjective characteristics of the carcass, the genotype influenced (p <0.05) in the variables color, marbling and meat texture. The genotype promoted significant effect (p <0.05) for the physical characteristics, water retention capacity and weight loss on cooking. The sensory attributes did not suffer significant effects (p> 0.05) of the evaluated genotypes. The genotypes influenced (p <0.05) in the concentrations of saturated fatty acids, monounsaturated and polyunsaturated as well as in the relations ω3: ω6 and AGM:AGS. The gender factor influenced (P <0.05) in the variables moisture, shear strength, hardness, desirable fatty acids and relation ω3: ω6. The cross between native breeds showed up with potential for quality meat production, the Morada Nova improved the physical and chemical attributes of the flesh and in their lipid profiles and sex factor improved softness attribute highlighting the meat of females.

Variability of thermohaline properties in Pearl Lagoon, Nicaragua (ESP)

Several hydrographic surveys were carried out in Pearl Lagoon, Nicaragua between april 1995 and december 1997 under the DIPAL (Proyecto para el Desarrollo Integral de la Pesca Artesanal en la Región Autónoma del Atlántico Sur) project. Surface temperature, salinity, dissolved oxygen and turbidity have been measured in 88 hydrographic campaigns. The annual cycle shows maximum and minimum temperatures in May (29.4 °C) and December (25.6 °C) respectively, maximum salinity (25.6 °C) in April, one month before the thermal peak, and minimum salinities (2‰) between July and August, when the annual precipitation index attains its seasonal maximum in the study area. In the case of dissolved O2 the maximum values of oxygen saturation were observed between March and May (90%), when the water turbidity in the lagoon is at its lowest and freshwater contributions from the rivers attains its minimum value. During the rainy season, in the second half of the year, there is an important decrease in oxygen contents, mainly as a consequence of the degradation of organic matter of riverine origin.

The Hitchin map for one-nodal base curves of compact type

Studying moduli spaces of semistable Higgs bundles (E, \phi) of rank n on a smooth curve C, a key role is played by the spectral curve X (Hitchin), because an important result by Beauville-Narasimhan-Ramanan allows us to study isomorphism classes of such Higgs bundles in terms of isomorphism classes of rank-1 torsion-free sheaves on X. This way, the generic fibre of the Hitchin map, which associates to any semistable Higgs bundle the coefficients of the characteristic polynomial of \phi, is isomorphic to the Jacobian of X. Focusing on rank-2 Higgs data, this construction was extended by Barik to the case in which the curve C is reducible, one-nodal, having two smooth components. Such curve is called of compact type because its Picard group is compact. In this work, we describe and clarify the main points of the construction by Barik and we give examples, especially concerning generic fibres of the Hitchin map. Referring to Hausel-Pauly, we consider the case of SL(2,C)-Higgs bundles on a smooth base curve, which are such that the generic fibre of the Hitchin map is a subvariety of the Jacobian of X, the Prym variety. We recall the description of special loci, called endoscopic loci, such that the associated Prym variety is not connected. Then, letting G be an affine reductive group having underlying Lie algebra so(4,C), we consider G-Higgs bundles on a smooth base curve. Starting from the construction by Bradlow-Schaposnik, we discuss the associated endoscopic loci. By adapting these studies to a one-nodal base curve of compact type, we describe the fibre of the SL(2,C)-Hitchin map and of the G-Hitchin map, together with endoscopic loci. In the Appendix, we give an interpretation of generic spectral curves in terms of families of double covers.

Synthesis of fluorinated 2-phenyl-4-quinolones from pyrrole-2,3-diones

A series of substituted 2-phenyl-4-quinolones 8-11 have been synthesized in good yields via ash vacuum thermolysis (FVT) of 1-aryl-4-cyano-5-phenylpyrrole-2,3-diones 7a-e and 1-aryl-4-methoxycarbonyl-5-phenylpyrrole-2,3-diones 7f-j. The pyrrolediones 7 were prepared from amines 3 and benzoylacetonitriles 5a-e or methyl 3-arylamino-3-phenylprop-2-enoates 5f-j.

BALB/c Mice Infected with Antimony Treatment Refractory Isolate of Leishmania braziliensis Present Severe Lesions due to IL-4 Production

Background: Leishmania braziliensis is the main causative agent of cutaneous leishmaniasis in Brazil. Protection against infection is related to development of Th1 responses, but the mechanisms that mediate susceptibility are still poorly understood. Murine models have been the most important tools in understanding the immunopathogenesis of L. major infection and have shown that Th2 responses favor parasite survival. In contrast, L. braziliensis-infected mice develop strong Th1 responses and easily resolve the infection, thus making the study of factors affecting susceptibility to this parasite difficult. Methodology/Principal Findings: Here, we describe an experimental model for the evaluation of the mechanisms mediating susceptibility to L. braziliensis infection. BALB/c mice were inoculated with stationary phase promastigotes of L. braziliensis, isolates LTCP393(R) and LTCP15171(S), which are resistant and susceptible to antimony and nitric oxide (NO), respectively. Mice inoculated with LTCP393(R) presented larger lesions that healed more slowly and contained higher parasite loads than lesions caused by LTCP15171(S). Inflammatory infiltrates in the lesions and production of IFN-gamma, TNF-alpha, IL-10 and TGF-beta were similar in mice inoculated with either isolate, indicating that these factors did not contribute to the different disease manifestations observed. In contrast, IL-4 production was strongly increased in LTCP393(R)-inoculated animals and also arginase I (Arg I) expression. Moreover, anti-IL-4 monoclonal antibody (mAb) treatment resulted in decreased lesion thickness and parasite burden in animals inoculated with LTCP393(R), but not in those inoculated with LTCP15171(S). Conclusion/Significance: We conclude that the ability of L. braziliensis isolates to induce Th2 responses affects the susceptibility to infection with these isolates and contributes to the increased virulence and severity of disease associated with them. Since these data reflect what happens in human infection, this model could be useful to study the pathogenesis of the L. braziliensis infection, as well as to design new strategies of therapeutic intervention.

The viability of three probiotic organisms grown with yoghurt starter cultures during storage for 21 days at 4 degrees C

This study investigated the viability of probiotic (Lactobacillus acidophilus LA5, Lactobacillus rhamnosus LBA and Bifidobacterium animalis subsp. lactis BL-04) in milk fermented with Lactobacillus delbrueckii subsp. bulgaricus LB340 and Streptococcus thermophilus TAO (yoghurt - Y). Each probiotic strain was grown separately in co-culture with Y and in blends of different combinations. Blends affected fermentation time(s), pH and firmness during storage at 4 degrees C. The product made with Y plus B. animalis subsp. lactis and L. rhamnosus had counts of viable cells at the end of shelf life that met the minimum required to achieve probiotic effect. However, L. acidophilus and L. delbrueckii subsp. bulgaricus were inhibited.

Correlation between carbon isotope discrimination and transpiration efficiency in lines of the C-4 species Sorghum bicolor in the glasshouse and the field

Transpiration efficiency, W, the ratio of plant carbon produced to water transpired and carbon isotope discrimination of leaf dry matter, Delta(d)' were measured together on 30 lines of the C-4 species, Sorghum bicolor in the glasshouse and on eight lines grown in the field. In the glasshouse, the mean W observed was 4.9 mmol C mol(-1) H2O and the range was 0.8 mmol C mol(-1) H2O The mean Delta(d) was 3.0 parts per thousand and the observed range was 0.4 parts per thousand. In the field, the mean W was lower at 2.8 mmol C mol H2O and the mean Delta(d) was 4.6 parts per thousand. Significant positive correlations between W and Delta(d) were observed for plants grown in the glasshouse and in the field. The observed correlations were consistent with theory, opposite to those for C-4 species, and showed that variation in Delta(d) was an integrated measure of long-term variation in the ratio of intercellular to ambient CO2 partial pressure, p(i)/p(a). Detailed gas exchange measurements of carbon isotope discrimination during CO2 uptake, Delta(A) and p(i)/p(a) were made on leaves of eight S. bicolor lines. The observed relationship between Delta(A) and p(i)/p(a) was linear with a negative slope of 3.7 parts per thousand in Delta(A) for a unit change in p(i)/p(a). The slope of this linear relationship between Delta(A) and p(i)/p(a) in C-4 species is dependent on the leakiness of the CO2 concentrating mechanism of the C pathway, We estimated the leakiness (defined as the fraction of CO2 released in the bundle sheath by C-4 acid decarboxylations, which is lost by leakage) to be 0.2. We conclude that, although variation in Delta(d) observed in the 30 lines of S. bicolor is smaller than that commonly observed in C-4 species, it also reflects variation in transpiration efficiency, W. Among the eight lines examined in detail and in the environments used, there was considerable genotype x environment interaction.

Spin states of C-60(3-) and C120On- (n=2, 3, 4) anions using electron spin transient nutation spectroscopy

Electron spin transient nutation (ESTN) experiments show that the spin multiplicity of the ground state of C-60(3-) in frozen solution is a doublet with S = 1/2. In purified samples, there is no evidence for excited states or other species with higher multiplicity. In the anions Of C120On- (n = 2, 3, 4), where the CW EPR experiments have shown that a mixture of species is present, ESTN experiments confirm that a doublet with S = 1/2 is associated with the 3- anion and triplets with S = 1 are associated with the 2- and 4- anions. A weak nutation peak attributable to m(s) = -1/2 1/2 transitions within a quartet state may arise from association of anions with spins of 1/2 and 1 in solute aggregates.

Unraveling the Na,K-ATPase alpha(4) Subunit Assembling Induced by Large Amounts of C(12)E(8) by Means of Small-Angle X-ray Scattering

In the current work, we studied the effect of the nonionic detergent dodecyloctaethyleneglycol, C(12)E(8), on the structure and oligomeric form of the Na,K-ATPase membrane enzyme (sodium-potassium pump) in aqueous suspension, by means of small-angle X-ray scattering (SAXS). Samples composed of 2 mg/mL of Na,K-ATPase, extracted from rabbit kidney medulla, in the presence of a small amount of C(12)E(8) (0.005 mg/mL) and in larger concentrations ranging from 2.7 to 27 mg/mL did not present catalytic activity. Under this condition, an oligomerization of the alpha subunits is expected. SAXS data were analyzed by means of a global fitting procedure supposing that the scattering is due to two independent contributions: one coming from the enzyme and the other one from C(12)E(8) micelles. In the small detergent content (0.005 mg/mL), the SAXS results evidenced that Na,K-ATPase is associated into aggregates larger than (alpha beta)(2) form. When 2.7 mg/mL of C(12)E(8) is added, the data analysis revealed the presence of alpha(4) aggregates in the solution and some free micelles. Increasing the detergent amount up to 27 mg/mL does not disturb the alpha(4) aggregate: just more micelles of the same size and shape are proportionally formed in solution. We believe that our results shed light on a better understanding of how nonionic detergents induce subunit dissociation and reassembling to minimize the exposure of hydrophobic residues to the aqueous solvent.

Conversion of glucosamine to galactosamine and allosamine derivatives: Control of inversions of stereochemistry at C-3 and C-4

The reactions of sodium benzoate with a series of trimesylates derived from glucosamine have been examined in an attempt to gain facile access to galactosamine analogues. Trimesylate 17, in which the amino group was protected as a phthalimide, underwent double displacement at positions 4 and 6 to give the dibenzoate 18 with the desired galactosamine configuration. In contrast, trimesylates 21 and 27, in which the amino groups were protected as acetamides, unexpectedly underwent double displacement at positions 3 and 6, giving products 22 and 28, respectively, with allosamine configurations.

Solubilities of C‑Tetraalkylcalix[4]resorcinarenes in SCCO2: experimental measurements, characterization, and correlation

The solubilities of two C-tetraalkylcalix[4]resorcinarenes, namely C-tetramethylcalix[4]resorcinarene and C-tetrapentylcalix[4]resorcinarene, in supercritical carbon dioxide (SCCO2) were measured in a flow-type apparatus at a temperature range from (313.2 to 333.2) K and at pressures from (12.0 to 35.0) MPa. The C-tetraalkylcalix[4]resorcinarenes were synthesized applying our optimized procedure and fully characterized by means of gel permeation chromatography, infrared and nuclear magnetic resonance spectroscopy. The solubilities of the C-tetraalkylcalix[4]resorcinarenes in SCCO2 were determined by analysis of the extracts obtained by HPLC with ultraviolet (UV) detection methodology adapted by our team. Four semiempirical density-based models, and the SoaveRedlichKwong cubic equation of state (SRK CEoS) with classical mixing rules, were applied to correlate the solubility of the calix[4]resorcinarenes in the SC CO2. The physical properties required for the modeling were estimated and reported.

Detecção do genótipo 4 do vírus da hepatite C em Salvador, BA

É descrito o primeiro caso de detecção do genótipo 4 do vírus da hepatite C (VHC) em Salvador, BA. Foram utilizados os testes de RT-PCR para detecção do VHC-RNA, e o LIPA para genotipagem. O genótipo 4 responde mal ao tratamento, sendo portanto importante a busca ativa dos contactantes.

Interleukin-4 production in BALB/c mice immunized with Anisakis simplex

We investigated the interleukin (IL-4) levels in BALB/c mice immunized with Anisakis extract in single or multiple doses and in mice orally infected with a larva. From animals immunized maximum responses were obtained with the multiple doses with an only IL-4 peak. Conversely, in the mice inoculated with a larva per os, the IL-4 levels showed two peaks of different rates.