Aspectos biológicos y poblacionales de Brevicoryne brassicae L. (Homoptera: Aphidoidea) en tres variedades comerciales de repollo (Brassica oleracea var. capitata L.) en condiciones de laboratorio

p.387-393En el presente trabajo, se obtuvieron y compararon los principales parámetros biológicos y poblacionales del áfido Brevicoryne brassicae sobre las variedades de repollo Ditchmark, Natsubare y Ryozeki. Las cohortes fueron criadas a 20 ± 1ºC; 14:10 horas (fotofase: escotofase) y aproximadamente 65-70 por ciento de humedad relativa. El período ninfal fue levemente más largo sobre Ryozeki, oscilando entre 9,36 y 9,52 días mientras que en las restantes duró entre 7,47 y 7,88 días. El periodo reproductivo y la longevidad fueron más cortos en Ditchmark mientras que la fecundidad (número total de hembras por hembra), resultó significativamente mayor en el cultivar Ryozeki. Se observaron diferencias significativas entre las rm de las cohortes criadas sobre Ditchmark (0,215-0,218) y Natsubare (0,200-0,201), mientras que el cultivar Ryozeki (0,209-0,214) arrojó valores intermedios; lo mismo ocurrió con la RQ. La confección de tablas de vida y la determinación de los estadísticos vitales permitió advertir que el cultivar Natsubare posee ciertas ventajas respecto de las demás

Aspectos morfológicos y biológicos de la oruga militar verdadera (Pseudaletia adultera (Schaus) ) (Lep. Noctuidae)

p.39-46Se detalla la importancia, denominación científica correcta y distribución geográfica de Pseudaletia adultera (Schaus), así como la metodología empleada para su cría en laboratorio. Se lleva a cabo una minuciosa descripción de los estados ontogénicos y de cada uno de los estadios larvales. Quedan determinados una serie de parámetros biológicos obtenidos en laboratorio con una temperatura ambiente de 23° a 27°C y una humedad relativa del 65 al 70 por ciento; por ejemplo, período embrionario 2 a 4 días, período larval 26 a 32 días, período pupal 12 días y longevidad de los adultos 12 a 19 días. Se informa acerca de su polifitofagismo y de los daños que suele ocasionar, especialmente en cereales. Finalmente se realiza una discusión sobre la base de los resultados obtenidos

Respuesta biológica y demográfica de los áfidos Nasonovia ribisnigri (Mosley) y Aulacorthum solani (Kaltenbach) (Hemiptera : Aphididae) sobre cuatro cultivares comerciales de lechuga en condiciones de laboratorio

p.17-24El objetivo del trabajo fue investigar la respuesta biológica y demográfica de los áfidos en cuatro cultivares de lechuga. En cámara climatizada a 10 más menos 1 oC, HR cercana al 90 por ciento y fotoperíodo de 14 h se criaron cohortes sobre plantulas. Los atributos biológicos y parámetros demográficos se analizaron mediante Kruskal-Wallis y el test de Wilcoxon con ƒ igual a 0,05. El período ninfal de Aulacorthum solani fue más largo en Veneza Roxa y Amarillo mientras que el reproductivo y la longevidad fueron menores en HMX 8574. Similar tendencia se observo en Nasonovia ribisnigri, excepto en Amarillo. La tasa intrinseca de crecimiento natural ((rm)de A. solani resultó significativamente baja sobre Amarillo, HMX y V. Roxa contrastando con Raider. En N. ribisnigri la menor rm ocurrió sobre V. Roxa y las mayores en Amarillo. A. solani podría alcanzar niveles poblacionales más altos sobre Raider y N. ribisnigri sobre Amarill

Effect of Constant and Cyclical Temperatures on the Mortality of Triatoma infestans (Klug) (Hemiptera: Reduviidae) Treated with Beauvaria bassiana (Bals.) Vuill. (Hyphomycetes)

Neotropical Entomology 34(4): Efecto de Temperaturas Constantes y Cíclicas sobre la Mortalidad de Triatoma infestans (Klug) (Hemiptera: Reduviidae) Tratada con Beauveria bassiana (Bals.) Vuill. PALABRAS CLAVE: Regímen fluctuante, germinación, hongo entomopatógeno ABSTRACT -The mortality of Triatoma infestans (Klug) treated with Beauvaria bassiana (Bals.) Vuill. under several temperature regimes was analyzed. Mortality rates were highest at 26ºC and 22ºC and lowest at constant 34ºC. The combinations 26/34ºC or 34/26ºC (12:12h cycles) were significantly different from the combinations 18/26ºC and 26/18ºC, showing that high temperatures (34ºC) affect mortality most significantly. The combinations also indicate that when an extreme high temperature is associated with an optimal temperature of 26ºC, the susceptibility of T. infestans to B. bassiana infection decreases. Exposure to extreme temperature (18ºC or 34ºC) associated with an optimal temperature of 26ºC in 8:8:8h cycles, reduces the mortality of T. infestans. In cycles of 6:6:6:6h, only the mortality associated with the 34/30/26/22ºC combination was similar to the combinations at constant 22ºC and 26ºC. Extreme temperatures during the first stage affect mortality less than when this period is not longer than 6h. Mortality decreases significantly when an extreme high initial temperature is followed by an abrupt fall (34/22/26/30ºC). Our results indicate that Beauvaria bassiana should be applied to the field in the late afternoon to avoid the negative impact of abrupt changes in temperature, or of high temperatures during the critical first stages of the infectious cycle of this entomopathogenic fungi. KEY WORDS: Fluctuating regime, germination, entomapathogenic fungus The blood-sucking bug Triatoma infestans (Klug) (Hemiptera: Reduviidae), the most important vector of Chagas disease, is well adapted to domestic and peridomestic habitats (Rabinovich 1972).The entomopathogenic fungus Beauvaria bassiana (Bals.) Vuill. (Hyphomycetes) controlled T. infestans under laboratory conditions (Lecuona et al. 2000). 676 Effect of Constant and Cyclical Temperatures on the Mortality of Triatoma... Lecuona et al. In insects, development of Hyphomycetes mycosis occurs in 10 stages The disease cycle is influenced by several factors, including environmental conditions such as temperature, relative humidity, and light (Alves 1998). Temperature is one of the most important factors because it affects both the growth of B. bassiana Material and Methods Populations of T. infestans. Specimens of T. infestans were collected in rural areas of Santiago del Estero by employees of the Servicio Nacional de Chagas (Cordoba, Argentina). The insects were reared in the laboratory at 27 ± 1ºC and 80 ± 10% relative humidity (R.H.), and fed on chickens. Thirdinstar nymphs (N3) that belonged to this colony were taken to the Laboratory of Entomopathogenic Fungi (Laboratorio de Hongos Entomopatógenos -IMYZA-INTA Castelar, Buenos Aires), where the experiments were conducted. Cultivation of B. bassiana. A strain Bb10 that belongs to the fungal culture collection of the IMYZA-INTA Castelar was used. The strain was isolated from Diatraea saccharalis (Fabricius) (Lepidoptera: Pyralidae), in Argentina. Before the strain could be used in this study, it was isolated a second time in nymphs of T. infestans. The strain was maintained in a petri dish with complete agar medium (CAM) containing (g/l): KH 2 PO 4 , 0.4; Na 2 HPO 4 , 1.4; MgSO 4 , 0.6; KCl, 1; NH 4 NO 3 , 0.7; glucose, 10; agar, 15; and yeast extract, 5. Conidia were extracted from 14-days old fungal colonies, and were incubated in petri dishes at 26 ± 0.5ºC. Viability was assessed at 18, 22, 26, 30 and 34 ± 0.5ºC by counting the number of conidia that had germinated. The conidia were incubated in CAM with 1 x 10 7 conidia/ml, in 10 microscopic fields 8, 12, 16, 20 and 24h after planting. Conidia are considered germinated when the germination tubule reaches a length that is the same, or greater than the widest part of the conidial body. Mortality of T. infestans under Constant and Fluctuating Temperature Regimes. The activity of the strain Bb10 on T. infestans was analyzed by means of a completely random design with 20 N3 nymphs in each repetition. The number of repetitions varied from six to 24, depending on the availability of insects. Nymphs were fed on chickens up to a week before the assays started. Inoculation was carried out by immersion, 6 min after each repetition, in a suspension of 1 x 10 8 conidia/ml in sterile water with 0.01% Tween 80. The insects were placed in a plastic cylindrical sieve (4 x 4.5 cm) for immersion. After immersion in the fungal suspension, each nymph was kept in a separate plastic container (4.5 x 2.5 cm), had their upper bodies covered with a voile fine cloth, and were maintained at different temperatures and in the dark, according to each treatment. The nymphs were not fed for 14 days. Control insects were dipped into sterile water with 0.01% Tween 80, also for six seconds. The assays were carried out at constant temperatures (18, 22, 26, 30 and 34 ± 0.5 o C), and daily temperature fluctuation cycles (12:12h, 8:8:8h and 6:6:6:6h). All the assays were conducted in the dark, at 80 ± 10% R.H. Nymph mortality was recorded daily, and cadavers were taken to a humid chamber (saturated atmosphere) for fungal sporulation. Mortality was analyzed by ANOVA and SNK, soon after the data arc sine transformation. Percentiles of the survival function were estimated by the Kaplan-Meier method Results and Discussion Mortality of T. infestans under Constant and Fluctuating Temperatures. Mortality percentage was higher at 26ºC in the 12:12h and 8:8:8h cycles, and at 26ºC and 22ºC in the 6:6:6:6h cycl

Discovery of Novel Biomarker Candidates for Liver Fibrosis in Hepatitis C Patients: A Preliminary Study

Background: Liver biopsy is the reference standard for assessing liver fibrosis and no reliable non-invasive diagnostic approach is available to discriminate between the intermediate stages of fibrosis. Therefore suitable serological biomarkers of liver fibrosis are urgently needed. We used proteomics to identify novel fibrosis biomarkers in hepatitis C patients with different degrees of liver fibrosis.Methodology/Principal Findings: Proteins in plasma samples from healthy control individuals and patients with hepatitis C virus (HCV) induced cirrhosis were analysed using a proteomics technique: two dimensional gel electrophoresis (2-DE). This technique separated the proteins in plasma samples of control and cirrhotic patients and by visualizing the separated proteins we were able to identify proteins which were increasing or decreasing in hepatic cirrhosis. Identified markers were validated across all Ishak fibrosis stages and compared to the markers used in FibroTest, Enhanced Liver Fibrosis (ELF) test, Hepascore and FIBROSpect by Western blotting. Forty four candidate biomarkers for hepatic fibrosis were identified of which 20 were novel biomarkers of liver fibrosis. Western blot validation of all candidate markers using plasma samples from patients across all Ishak fibrosis scores showed that the markers which changed with increasing fibrosis most consistently included lipid transfer inhibitor protein, complement C3d, corticosteroid-binding globulin, apolipoprotein J and apolipoprotein L1. These five novel fibrosis markers which are secreted in blood showed a promising consistent change with increasing fibrosis stage when compared to the markers used for the FibroTest, ELF test, Hepascore and FIBROSpect. These markers will be further validated using a large clinical cohort.Conclusions/Significance: This study identifies 20 novel fibrosis biomarker candidates. The proteins identified may help to assess hepatic fibrosis and eliminate the need for invasive liver biopsies.</br

Visualization and Quantitative Analysis of Reconstituted Tight Junctions Using Localization Microscopy

Tight Junctions (TJ) regulate paracellular permeability of tissue barriers. Claudins (Cld) form the backbone of TJ-strands. Pore-forming claudins determine the permeability for ions, whereas that for solutes and macromolecules is assumed to be crucially restricted by the strand morphology (i.e., density, branching and continuity). To investigate determinants of the morphology of TJ-strands we established a novel approach using localization microscopy

Gene co-regulation by Fezf2 selects neurotransmitter identity and connectivity of corticospinal neurons

The neocortex contains an unparalleled diversity of neuronal subtypes, each defined by distinct traits that are developmentally acquired under the control of subtype-specific and pan-neuronal genes. The regulatory logic that orchestrates the expression of these unique combinations of genes is unknown for any class of cortical neuron. Here, we report that Fezf2 is a selector gene able to regulate the expression of gene sets that collectively define mouse corticospinal motor neurons (CSMN). We find that Fezf2 directly induces the glutamatergic identity of CSMN via activation of Vglut1 (Slc17a7) and inhibits a GABAergic fate by repressing transcription of Gad1. In addition, we identify the axon guidance receptor EphB1 as a target of Fezf2 necessary to execute the ipsilateral extension of the corticospinal tract. Our data indicate that co-regulated expression of neuron subtype–specific and pan-neuronal gene batteries by a single transcription factor is one component of the regulatory logic responsible for the establishment of CSMN identity

Association of kidney disease measures with risk of renal function worsening in patients with type 1 diabetes

Background: Albuminuria has been classically considered a marker of kidney damage progression in diabetic patients and it is routinely assessed to monitor kidney function. However, the role of a mild GFR reduction on the development of stage 653 CKD has been less explored in type 1 diabetes mellitus (T1DM) patients. Aim of the present study was to evaluate the prognostic role of kidney disease measures, namely albuminuria and reduced GFR, on the development of stage 653 CKD in a large cohort of patients affected by T1DM. Methods: A total of 4284 patients affected by T1DM followed-up at 76 diabetes centers participating to the Italian Association of Clinical Diabetologists (Associazione Medici Diabetologi, AMD) initiative constitutes the study population. Urinary albumin excretion (ACR) and estimated GFR (eGFR) were retrieved and analyzed. The incidence of stage 653 CKD (eGFR &lt; 60 mL/min/1.73 m2) or eGFR reduction &gt; 30% from baseline was evaluated. Results: The mean estimated GFR was 98 \ub1 17 mL/min/1.73m2 and the proportion of patients with albuminuria was 15.3% (n = 654) at baseline. About 8% (n = 337) of patients developed one of the two renal endpoints during the 4-year follow-up period. Age, albuminuria (micro or macro) and baseline eGFR &lt; 90 ml/min/m2 were independent risk factors for stage 653 CKD and renal function worsening. When compared to patients with eGFR &gt; 90 ml/min/1.73m2 and normoalbuminuria, those with albuminuria at baseline had a 1.69 greater risk of reaching stage 3 CKD, while patients with mild eGFR reduction (i.e. eGFR between 90 and 60 mL/min/1.73 m2) show a 3.81 greater risk that rose to 8.24 for those patients with albuminuria and mild eGFR reduction at baseline. Conclusions: Albuminuria and eGFR reduction represent independent risk factors for incident stage 653 CKD in T1DM patients. The simultaneous occurrence of reduced eGFR and albuminuria have a synergistic effect on renal function worsening