Determination of Number of Instars of Rhyssomatus subtilis (Coleoptera: Curculionidae) Based on Head Capsule Widths

Rhyssomatus subtilis Fiedler (Coleoptera: Curculionidae) es una importante plaga del cultivo de soja en el Noroeste Argentino. Existen pocos estudios acerca de parámetros específicos del ciclo de vida y de comportamiento ecológico. El objetivo de este estudio fue determinar el número de instares larvales de R. subtilis. En total, 1018 larvas fueron colectadas del cultivo de soja durante 2011 y 2013. Se midió el ancho de la cápsula cefálica de cada larva. Para el análisis de los datos se utilizó el programa Hcap y la regla de Dyar. El programa Hcap mostró cuatro picos distintos en la distribución de frecuencias de la anchura de la cápsula cefálica. Estos resultados concuerdan con la regla de Dyar que muestra un perfecto crecimiento geométricos de las larvas para cada instar representada por la línea de regresión. El excelente ajuste del modelo lineal, indica que no hay instares solapados. Esta investigación identificó cuatro instares larvales para R. subtilis.Rhyssomatus subtilis Fiedler (Coleoptera: Curculionidae) is an important pest of the soybean crop in northwestern Argentina. Few studies have been made on specific parameters of its life history and ecology. The aim of this study was to determine the number of larval stages of R. subtilis. One thousand and eighteen larvae were collected from soybean plants during 2 yr (2011 and 2013), and head capsule width of each larva was measured. For analysis of data, the Hcap program and Dyar's rule were used. The Hcap program showed 4 different peaks in the frequency distribution of the head capsule widths. This result also agreed with Dyar's rule that revealed a perfect geometric larval growth pattern for each instar by regression analysis. The excellent fit to a linear model, indicates that no instar was overlooked. This research identified 4 instars for R. subtilis.Fil: Cazado, Lucas Emiliano. Gobierno de Tucumán. Ministerio de Desarrollo Productivo. Estación Experimental Agroindustrial Obispo Colombres; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto de Tecnología Agroindustrial del Noroeste Argentino. Provincia de Tucumán. Ministerio de Desarrollo Productivo. Estación Experimental Agroindustrial "Obispo Colombres"(p). Instituto de Tecnología Agroindustrial del Noroeste Argentino; ArgentinaFil: Van Nieuwenhove, Guido Alejandro. Gobierno de Tucumán. Ministerio de Desarrollo Productivo. Estación Experimental Agroindustrial Obispo Colombres; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: O'brien, C. W.. No especifica;Fil: Gastaminza, Gerardo Alfredo. Gobierno de Tucumán. Ministerio de Desarrollo Productivo. Estación Experimental Agroindustrial Obispo Colombres; ArgentinaFil: Murúa, María Gabriela. Gobierno de Tucumán. Ministerio de Desarrollo Productivo. Estación Experimental Agroindustrial Obispo Colombres; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto de Tecnología Agroindustrial del Noroeste Argentino. Provincia de Tucumán. Ministerio de Desarrollo Productivo. Estación Experimental Agroindustrial "Obispo Colombres"(p). Instituto de Tecnología Agroindustrial del Noroeste Argentino; Argentin

<i>In vivo</i> X-ray elemental imaging of single cell model organisms manipulated by laser-based optical tweezers

We report on a radically new elemental imaging approach for the analysis of biological model organisms and single cells in their natural, in vivo state. The methodology combines optical tweezers (OT) technology for non-contact, laser-based sample manipulation with synchrotron radiation confocal X-ray fluorescence (XRF) microimaging for the first time. The main objective of this work is to establish a new method for in vivo elemental imaging in a two-dimensional (2D) projection mode in free-standing biological microorganisms or single cells, present in their aqueous environment. Using the model organism Scrippsiella trochoidea, a first proof of principle experiment at beamline ID13 of the European Synchrotron Radiation Facility (ESRF) demonstrates the feasibility of the OT XRF methodology, which is applied to study mixture toxicity of Cu-Ni and Cu-Zn as a result of elevated exposure. We expect that the new OT XRF methodology will significantly contribute to the new trend of investigating microorganisms at the cellular level with added in vivo capability

The N137 and P140 amino acids in the p51 and the P95 amino acid in the p66 subunit of human immunodeficiency virus type 1 (HIV-1) reverse transcriptase are instrumental to maintain catalytic activity and to design new classes of anti-HIV-1 drugs

Amino acids N137 and P140 in the p51 subunit of HIV-1 reverse transcriptase (RT) are part of the β7-β8-loop that contributes to the formation of the base of the non-nucleoside RT inhibitor (NNRTI)-binding pocket and makes up a substantial part of the dimerization interface. Amino acid P95 in p66 also markedly contributes to the dimerization binding energy. Nine RT mutants at amino acid 137 were constructed bearing the mutations Y, K, T, D, A, Q, S, H or E. The prolines at amino acid positions 95 and 140 were replaced by alanine in separate enzymes. We found that all mutant RT enzymes showed a dramatically decreased RNA-dependent DNA polymerase activity. None of the mutant RT enzymes showed marked resistance against any of the clinically used NNRTIs but they surprisingly lost significant sensitivity for NRTIs such as ddGTP. The denaturation analyses of the mutant RTs by urea are suggestive for a relevant role of N137 in the stability of the RT heterodimer and support the view that the β7-β8 loop in p51 is a hot spot for RT dimerization and instrumental for efficient polymerase catalytic activity. Consequently, N137 and P140 in p51 and P95 in p66 should be attractive targets in the design of new structural classes of RT inhibitors aimed at compromising the optimal interaction of the β7-β8 loop in p51 at the p66/p51 dimerization interface. © 2005 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.We thank Kristien Minner for excellent technical assistance. This work was supported by the European Commission [No. QLRT-2000-30291 (HIV resistance), HPAW-2002-10004 (Rene´ Descartes Prize-2001) and QLRT-2001-01311 (Virulence)], the ‘‘Fonds voor Wetenschappelijk Onderzoek – Vlaanderen’’ (No. G-0267-04), a Research Grant from GlaxoSmithKline, Verona, Italy, and a Research Grant from the Spanish MEC (Ministerio de Educacion y Ciencia) (No. SAF2003-07219-C02-01). J.A. acknowledges a Ph.D. grant from the Institute for the Promotion of Innovation through Science and Technology in Flanders (IWT-Vlaande

Quantifying the burden of rhodesiense sleeping sickness in Urambo district, Tanzania

Sleeping sickness (human African trypanosomiasis - HAT) is a disease transmitted by tsetse flies and is always fatal if left untreated. The disease occurs in foci affecting poor communities with limited access to health service provision and as such the disease is often left undiagnosed, mistaken for more common afflictions. Even if diagnosed, sleeping sickness is costly to treat, both for health services and patients and their families in terms of costs of diagnosis, transport, hospital care, and the prolonged period of convalescence. Here we estimate the health burden of the acute form T. b. rhodesiense sleeping sickness in Urambo District, Tanzania in terms of Disability Adjusted Life Years (DALYs), the yardstick commonly used by policy makers to prioritize disease management practices, representing a year of healthy life lost to disease. In this single district, the burden of the disease over one year was estimated at 979 DALYs and the estimated monetary costs to health services for the 143 treated patients at US$11,841 and to the patients themselves at US$ 3,673 for direct medical costs and US$ 9,781 for indirect non-medical costs. Sleeping sickness thus places a considerable burden on the affected rural communities and health services

The genome sequence of <i>Trypanosoma brucei gambiense</i>, causative agent of chronic Human African Trypanosomiasis

&lt;p&gt;&lt;b&gt;Background:&lt;/b&gt; &lt;i&gt;Trypanosoma brucei gambiense&lt;/i&gt; is the causative agent of chronic Human African Trypanosomiasis or sleeping sickness, a disease endemic across often poor and rural areas of Western and Central Africa. We have previously published the genome sequence of a &lt;i&gt;T. b. brucei&lt;/i&gt; isolate, and have now employed a comparative genomics approach to understand the scale of genomic variation between &lt;i&gt;T. b. gambiense&lt;/i&gt; and the reference genome. We sought to identify features that were uniquely associated with &lt;i&gt;T. b. gambiense&lt;/i&gt; and its ability to infect humans.&lt;/p&gt; &lt;p&gt;&lt;b&gt;Methods and findings:&lt;/b&gt; An improved high-quality draft genome sequence for the group 1 &lt;i&gt;T. b. gambiense&lt;/i&gt; DAL 972 isolate was produced using a whole-genome shotgun strategy. Comparison with &lt;i&gt;T. b. brucei&lt;/i&gt; showed that sequence identity averages 99.2% in coding regions, and gene order is largely collinear. However, variation associated with segmental duplications and tandem gene arrays suggests some reduction of functional repertoire in &lt;i&gt;T. b. gambiense&lt;/i&gt; DAL 972. A comparison of the variant surface glycoproteins (VSG) in &lt;i&gt;T. b. brucei&lt;/i&gt; with all &lt;i&gt;T. b. gambiense&lt;/i&gt; sequence reads showed that the essential structural repertoire of VSG domains is conserved across &lt;i&gt;T. brucei&lt;/i&gt;.&lt;/p&gt; &lt;p&gt;&lt;b&gt;Conclusions:&lt;/b&gt; This study provides the first estimate of intraspecific genomic variation within &lt;i&gt;T. brucei&lt;/i&gt;, and so has important consequences for future population genomics studies. We have shown that the &lt;i&gt;T. b. gambiense&lt;/i&gt; genome corresponds closely with the reference, which should therefore be an effective scaffold for any &lt;i&gt;T. brucei&lt;/i&gt; genome sequence data. As VSG repertoire is also well conserved, it may be feasible to describe the total diversity of variant antigens. While we describe several as yet uncharacterized gene families with predicted cell surface roles that were expanded in number in &lt;i&gt;T. b. brucei&lt;/i&gt;, no &lt;i&gt;T. b. gambiense&lt;/i&gt;-specific gene was identified outside of the subtelomeres that could explain the ability to infect humans.&lt;/p&gt

Effects of Goat Manure Fertilization on Grain Nutritional Value in Two Contrasting Quinoa (Chenopodium quinoa Willd.) Varieties Cultivated at High Altitudes

In this study, the effects of goat manure fertilization (2, 4, 8, and 12 Tn/ha) on the grain yield, organic compounds, and mineral composition of two quinoa varieties (CICA-17 and Regalona Baer) were evaluated under field conditions in Northwest Argentina. The results indicate that fertilization improved the quinoa grain yield and total protein content. Low manure doses positively affected the fatty acid (FA) profile, and significant changes were determined for the monounsaturated (MUFA) and polyunsaturated (PUFA) fatty acid contents of CICA-17 and on the saturated fatty acid (SFA) contents of R. Baer seeds. The amino acid contents were positively affected in CICA-17 and negatively in R. Baer. Soluble sugars (glucose, fructose, and sucrose), major elements (K, Si, P, Mg, Ca, and Na), minor elements (Fe, Mn, Al, Zn, and Cu), and ultratrace elements (Cr and Li) were detected and discussed in terms of their impact on human nutrition and health. Conclusively, manure addition affected some essential amino acids, the desaturase activity, the n6:n3 and SFA/UFA ratios, the atherogenic index, soluble sugars, and mineral content, and the fatty acid metabolism of each variety was differently affected, especially the C16 and C18 desaturase activity, which responded differently to various manure doses. Manure addition is a promising alternative to improve the nutritional quality and functionality of quinoa grains, but the response is not linear

The absolute abundance calibration project: the <i>Lycopodium</i> marker-grain method put to the test

Traditionally, dinoflagellate cyst concentrations are calculated by adding an exotic marker or “spike” (such as Lycopodium clavatum) to each sample following the method of Stockmarr (1971). According to Maher (1981), the total error is controlled mainly by the error on the count of Lycopodium clavatum spores. In general, the more L. clavatum spores counted, the lower the error. A dinocyst / L. clavatum spore ratio of ~2 will give optimal results in terms of precision and time spent on a sample. It has also been proven that the use of the aliquot method yields comparable results to the marker-grain method (de Vernal et al., 1987). Critical evaluation of the effect of different laboratory procedures on the marker grain concentration in each sample has never been executed. Although, it has been reported that different processing methods (e.g. ultrasonication, oxidizing, etc.) are to a certain extent damaging to microfossils (e.g. Hodgkinson, 1991), it is not clear how this is translated into concentration calculations. It is wellknown from the literature that concentration calculations of dinoflagellate cysts from different laboratories are hard to resolve into a consistent picture. The aim of this study is to remove these inconsistencies and to make recommendations for the use of a standardized methodology. Sediment surface samples from four different localities (North Sea, Celtic Sea, NW Africa and Benguela) were macerated in different laboratories each using its own palynological maceration technique. A fixed amount of Lycopodium clavatum tablets was added to each sample. The uses of different preparation methodologies (sieving, ultrasonicating, oxidizing …) are compared using both concentrations – calculated from Lycopodium tablets - and relative abundances (more destructive methods will increase the amount of resistant taxa). Additionally, this study focuses on some important taxonomic issues, since obvious interlaboratorial differences in nomenclature are recorded

Analysis of risk factors for T. brucei rhodesiense sleeping sickness within villages in south-east Uganda

<p>Abstract</p> <p>Background</p> <p>Sleeping sickness (HAT) caused by <it>T.b. rhodesiense </it>is a major veterinary and human public health problem in Uganda. Previous studies have investigated spatial risk factors for <it>T.b. rhodesiense </it>at large geographic scales, but none have properly investigated such risk factors at small scales, i.e. within affected villages. In the present work, we use a case-control methodology to analyse both behavioural and spatial risk factors for HAT in an endemic area.</p> <p>Methods</p> <p>The present study investigates behavioural and occupational risk factors for infection with HAT within villages using a questionnaire-based case-control study conducted in 17 villages endemic for HAT in SE Uganda, and spatial risk factors in 4 high risk villages. For the spatial analysis, the location of homesteads with one or more cases of HAT up to three years prior to the beginning of the study was compared to all non-case homesteads. Analysing spatial associations with respect to irregularly shaped geographical objects required the development of a new approach to geographical analysis in combination with a logistic regression model.</p> <p>Results</p> <p>The study was able to identify, among other behavioural risk factors, having a family member with a history of HAT (p = 0.001) as well as proximity of a homestead to a nearby wetland area (p < 0.001) as strong risk factors for infection. The novel method of analysing complex spatial interactions used in the study can be applied to a range of other diseases.</p> <p>Conclusion</p> <p>Spatial risk factors for HAT are maintained across geographical scales; this consistency is useful in the design of decision support tools for intervention and prevention of the disease. Familial aggregation of cases was confirmed for <it>T. b. rhodesiense </it>HAT in the study and probably results from shared behavioural and spatial risk factors amongmembers of a household.</p