Mancha Ojo de Rana (Cercospora sojina K. Hara) y su efecto sobre rendimiento y componentes industriales del grano de soja : prote��na y aceite

La mancha ojo de rana (MOR), causada por Cercospora sojina K. Hara, se encuentra dentro del complejo de enfermedades f��ngicas de fin de ciclo (EFC), que afectan al cultivo de soja (Glycine max (L.) Merr.) preferentemente en los estad��os reproductivos. Es una enfermedad com��n en la soja en la mayor parte de las regiones sojeras del mundo, incluyendo Argentina. Con los objetivos de (i) estudiar el efecto de MOR sobre rendimiento y calidad industrial del grano de soja y (ii) analizar la respuesta a distintos momentos de aplicaci��n de estrobilurina+triazol durante el ciclo reproductivo del cultivo para disminuir el da��o de esta enfermedad evitando p��rdidas del rendimiento y de calidad del grano, se realiz�� un ensayo durante la campa��a agr��cola 2010-2011, en la localidad de Oncativo (Cordoba), que involucr�� 2 genotipos contrastantes en susceptibilidad a MOR. Se realizaron para cada cultivar cuatro tratamientos con una mezcla de triazol y estrobilurina: T1= aplicaci��n en R3; T2= aplicaci��n en R3+R5; T3= testigo enfermo (sin aplicaci��n de fungicida) y T4= testigo sano (aplicacion cada 20 dias a partir de R1). Se determin�� el nivel de incidencia y severidad de la enfermedad, rendimiento, n��mero de grano por m2 (NGm2), peso de mil semillas (PMA), concentraci��n de prote��na (Pr) y aceite (Ac) del grano. Se observaron distintos niveles de severidad de MOR entre los tratamientos del cultivar DM3700. Todos los tratamientos que involucraron a DM3810 mostraron hojas sin manchas de MOR. Se encontr�� una correlaci��n negativa entre la severidad de MOR y el rendimiento alcanzado por el cultivo. Los valores m��s elevados de severidad (37,3 por ciento de manchas foliares) se correspondieron con los rendimientos mas bajos (2117 kg ha-1) en el cultivar DM3700. Todos los tratamientos aplicados a DM3810 exhibieron los rendimientos mas elevados y no se diferenciaron estadisticamente entre si (3478 kg ha-1). DM3700 alcanz�� rendimientos similares a DM3810 s��lo cuando se aplic�� la mezcla de fungicidas en T1 y T4, no diferenci��ndose entre si ambos tratamientos y mostrando un incremento en el rendimiento de aproximadamente 35,5 por ciento comparado con su testigo enfermo. Ambos componentes del rendimiento disminuyeron en el testigo enfermo DM3700; sin embargo, las reducciones en el NGm2 fueron m��s pronunciadas que las del PMAj y; por lo tanto, disminuciones en el NGm2 parec��an ser el principal componente de la p��rdida de rendimiento. No se observaron incrementos de rendimiento, NGm2 y/o PMAj atribu��dos a la mezcla estrobilurinas + triazoles en los tratamientos que involucraron a DM3810 ante ausencia de MOR. La severidad m��xima alcanzada por MOR en el genotipo mas susceptible (37,3 por ciento) de area foliar da��ada en el tratamiento enfermo de DM3700) no fue suficiente como para causar disminuci��n significativa en la acumulaci��n del aceite. Seg��n nuestro conocimiento este trabajo es el primero en demostrar que genotipos susceptibles a MOR disminuyen su rendimiento, pero no la calidad qu��mica del grano, si la severidad es . 37,3 por cientoy pueden ser controlados con una ��nica aplicaci��n de estrobilurina+triazol en R3. Concluy��ndose que la elecci��n de genotipos poco susceptibles a MOR (como DM3810) es efectiva para controlar C. sojina, sin beneficios adicionales en el rendimiento debidos a la aplicacion de fungicidas.

Influencia del nitr��geno, f��sforo y cinc sobre la composici��n qu��mica y rendimiento de la nuez pec��n y su relaci��n con la variabilidad de nutrientes en hoja

El pec��n (Carya illinoinensis (Wangenh.) K. Koch) es una especie frutal y forestal nativa de Am��rica del Norte. Estados Unidos y Mexico representan m��s del 90 por ciento de la superficie y producci��n mundial. Argentina ocupa el tercer lugar en el mundo en superficie con 6000 hect��reas implantadas, la mayor��a de la cuales se encuentran a��n en una etapa juvenil con bajos rendimientos. En el pa��s no hay estudios sobre la respuesta a la fertilizaci��n del ��rbol de pec��n en producci��n. En la presente tesis se investig�� el efecto de la fertilizaci��n con distintos niveles de nitr��geno (N), f��sforo (P) y cinc (Zn) sobre el crecimiento vegetativo, rendimiento y composici��n qu��mica de la hoja y del fruto de ��rboles de pecan cultivar 'Stuart'. Tambi��n se evalu�� el efecto de la fertilizaci��n sobre la concentraci��n de extracto et��reo, tocoferol y prote��na en embri��n. La fertilizaci��n tuvo efecto en el corto plazo sobre las variables tasa de crecimiento en altura y di��metro del ��rbol mientras que en el rendimiento el efecto fue m��s tard��o. Los tratamientos en kg ha-1 fueron: testigo (T); tratamiento 1 (T1) con 13,2 kg de N , 5,2 kg de P y 5,4 kg de Zn; tratamiento 2 (T2) con 29,7 kg de N , 10,5 kg de P y 10,8 kg de Zn y tratamiento 3 (T3) con 46,2 kg de N , 15,7 kg de P y 21,6 kg de Zn. Se obtuvo la siguiente respuesta en peso de materia seca (MS) de embri��n ��rbol-1: 227 g Testigo (T), 340 g Tratamiento 1 (T1), 301 g Tratamiento 2 (T2) y 558 g Tratamiento 3 (T3). El extracto et��reo no fue influ��do por la fertilizaci��n teniendo una concentraci��n entre 71,51 por ciento y 75,12 por ciento mientras que en su composici��n en ��cidos grasos predominaron los ��cidos oleico (C 18:1) con 62,49 por ciento y linoleico (C 18:2) con 26,63 por ciento. Los is��meros ����-tocoferol, ����-tocoferol y ���� +����-tocoferol tampoco presentaron respuesta a la fertilizaci��n, predominado el ����-tocoferol con una concentraci��n en peso de materia h��meda (MH) de embri��n entre 45,96 mg y 55,32 mg ����-tocoferol 100 g MH-1. La fertilizaci��n tuvo influencia sobre el contenido de prote��na en el embri��n presentando los siguientes valores en porcentaje de MS de embri��n: 7,65 por ciento T, 7,81 por ciento T1, 8,36 por ciento T2 y 9 por ciento T3. La fertilizaci��n influy�� positivamente sobre la concentraci��n de N foliar, negativamente sobre la concentraci��n de P foliar y no tuvo efecto sobre la concentraci��n de Zn foliar. Se encontr�� una relaci��n lineal positiva entre el N foliar de verano y el peso seco de embri��n y una relaci��n lineal negativa entre el N foliar de verano y el contenido de prote��na en embri��n. La fertilizaci��n con N, P y Zn tuvo una influencia positiva sobre el crecimiento y rendimiento del ��rbol de pecan y la concentraci��n de prote��na en embri��n. Sin embargo, la fertilizaci��n no tuvo efecto sobre la concentraci��n de extracto etereo e is��meros de tocoferol en embri��n

Maternal effect on salinity tolerance during germination of Ricinus communis

p.93-101

Fertilization trial on soybean in Argentine Pampa : boron or nitrogen?

p.29-36

Influencia del nitr��geno, f��sforo y cinc sobre la composici��n qu��mica y rendimiento de la nuez pec��n y su relaci��n con la variabilidad de nutrientes en hoja

El pec��n (Carya illinoinensis (Wangenh.)K. Koch)es una especie frutal y forestal nativa de Am��rica del Norte. Estados Unidos y Mexico representan m��s del 90 por ciento de la superficie y producci��n mundial. Argentina ocupa el tercer lugar en el mundo en superficie con 6000 hect��reas implantadas, la mayor��a de la cuales se encuentran a��n en una etapa juvenil con bajos rendimientos. En el pa��s no hay estudios sobre la respuesta a la fertilizaci��n del ��rbol de pec��n en producci��n. En la presente tesis se investig�� el efecto de la fertilizaci��n con distintos niveles de nitr��geno (N), f��sforo (P)y cinc (Zn)sobre el crecimiento vegetativo, rendimiento y composici��n qu��mica de la hoja y del fruto de ��rboles de pecan cultivar 'Stuart'. Tambi��n se evalu�� el efecto de la fertilizaci��n sobre la concentraci��n de extracto et��reo, tocoferol y prote��na en embri��n. La fertilizaci��n tuvo efecto en el corto plazo sobre las variables tasa de crecimiento en altura y di��metro del ��rbol mientras que en el rendimiento el efecto fue m��s tard��o. Los tratamientos en kg ha-1 fueron: testigo (T); tratamiento 1 (T1)con 13,2 kg de N , 5,2 kg de P y 5,4 kg de Zn; tratamiento 2 (T2)con 29,7 kg de N , 10,5 kg de P y 10,8 kg de Zn y tratamiento 3 (T3)con 46,2 kg de N , 15,7 kg de P y 21,6 kg de Zn. Se obtuvo la siguiente respuesta en peso de materia seca (MS)de embri��n ��rbol-1: 227 g Testigo (T), 340 g Tratamiento 1 (T1), 301 g Tratamiento 2 (T2)y 558 g Tratamiento 3 (T3). El extracto et��reo no fue influ��do por la fertilizaci��n teniendo una concentraci��n entre 71,51 por ciento y 75,12 por ciento mientras que en su composici��n en ��cidos grasos predominaron los ��cidos oleico (C 18:1)con 62,49 por ciento y linoleico (C 18:2)con 26,63 por ciento. Los is��meros ����-tocoferol, ����-tocoferol y ���� +����-tocoferol tampoco presentaron respuesta a la fertilizaci��n, predominado el ����-tocoferol con una concentraci��n en peso de materia h��meda (MH)de embri��n entre 45,96 mg y 55,32 mg ����-tocoferol 100 g MH-1. La fertilizaci��n tuvo influencia sobre el contenido de prote��na en el embri��n presentando los siguientes valores en porcentaje de MS de embri��n: 7,65 por ciento T, 7,81 por ciento T1, 8,36 por ciento T2 y 9 por ciento T3. La fertilizaci��n influy�� positivamente sobre la concentraci��n de N foliar, negativamente sobre la concentraci��n de P foliar y no tuvo efecto sobre la concentraci��n de Zn foliar. Se encontr�� una relaci��n lineal positiva entre el N foliar de verano y el peso seco de embri��n y una relaci��n lineal negativa entre el N foliar de verano y el contenido de prote��na en embri��n. La fertilizaci��n con N, P y Zn tuvo una influencia positiva sobre el crecimiento y rendimiento del ��rbol de pecan y la concentraci��n de prote��na en embri��n. Sin embargo, la fertilizaci��n no tuvo efecto sobre la concentraci��n de extracto etereo e is��meros de tocoferol en embri��n

Fertilization trial on soybean in Argentine Pampa : boron or nitrogen?

p.29-36

Ocurrencia de micorrizas en plantas de ma��z, soja y trigo en sistemas de siembra directa

p.67-72

Evaluaci��n de terneza de reses de novillos Hereford bajo distintos modelos de invernada en el partido de Carlos Casares

p.77-85

Measuring distributions of jump rates in disordered metal���hydrogen systems by nuclear magnetic relaxation

Monte Carlo calculations of the nuclear magnetic relaxation rate in a disordered metal���hydrogen system having a distribution of jump rates are reported. The calculations deal specifically with the spin-locked rotating-frame relaxation time T1��. The results demonstrate that the temperature variation of the rate is only weakly dependent on the distribution and it is therefore unlikely that the jump rate distribution can be extracted from relaxation measurements in which temperature is the main variable. It is shown that the alternative of measuring the relaxation rate over a wide range of spin-locking field strengths at a constant temperature can lead to an evaluation of the distribution.

Ocean acidification shows negligible impacts on high-latitude bacterial community structure in coastal pelagic mesocosms

The impact of ocean acidification and carbonation on microbial community structure was assessed during a large-scale in situ costal pelagic mesocosm study, included as part of the EPOCA 2010 Arctic campaign. The mesocosm experiment included ambient conditions (fjord) and nine mesocosms with pCO(2) levels ranging from similar to 145 to similar to 1420 mu atm. Samples for the present study were collected at ten time points (t-1, t1, t5, t7, t12, t14, t18, t22, t26 to t28) in seven treatments (ambient fjord (similar to 145), 2x similar to 185, similar to 270, similar to 685, similar to 820, similar to 1050 mu atm) and were analysed for "small" and "large" size fraction microbial community composition using 16S rRNA (ribosomal ribonucleic acid) amplicon sequencing. This high-throughput sequencing analysis produced similar to 20 000 000 16S rRNA V4 reads, which comprised 7000OTUs. The main variables structuring these communities were sample origins (fjord or mesocosms) and the community size fraction (small or large size fraction). The community was significantly different between the unenclosed fjord water and enclosed mesocosms (both control and elevated CO2 treatments) after nutrients were added to the mesocosms, suggesting that the addition of nutrients is the primary driver of the change in mesocosm community structure. The relative importance of each structuring variable depended greatly on the time at which the community was sampled in relation to the phytoplankton bloom. The sampling strategy of separating the small and large size fraction was the second most important factor for community structure. When the small and large size fraction bacteria were analysed separately at different time points, the only taxon pCO(2) was found to significantly affect were the Gammaproteobacteria after nutrient addition. Finally, pCO(2) treatment was found to be significantly correlated (non-linear) with 15 rare taxa, most of which increased in abundance with higher CO2.

Improved stability, insulin-releasing activity and antidiabetic potential of two novel N-terminal analogues of gastric inhibitory polypeptide: N-acetyl-GIP and pGlu-GIP

Aims/hypothesis: This study examined the plasma stability, biological activity and antidiabetic potential of two novel N-terminally modified analogues of gastric inhibitory polypeptide (GIP).<br/><br/>Methods: Degradation studies were carried out on GIP, N-acetyl-GIP (Ac-GIP) and N-pyroglutamyl-GIP (pGlu-GIP) in vitro following incubation with either dipeptidylpeptidase IV or human plasma. Cyclic adenosine 3'5' monophosphate (cAMP) production was assessed in Chinese hamster lung fibroblast cells transfected with the human GIP receptor. Insulin-releasing ability was assessed in vitro in BRIN-BD11 cells and in obese diabetic (ob/ob) mice.<br/><br/>Results: GIP was rapidly degraded by dipeptidylpeptidase IV and plasma (t1/2 2.3 and 6.2 h, respectively) whereas Ac-GIP and pGlu-GIP remained intact even after 24 h. Both Ac-GIP and pGlu-GIP were extremely potent (p&lt;0.001) at stimulating cAMP production (EC50 values 1.9 and 2.7 nmol/l, respectively), almost a tenfold increase compared to native GIP (18.2 nmol/l). Both Ac-GIP and pGlu-GIP (10���13���10���8 mmol/l) were more potent at stimulating insulin release compared to the native GIP (p&lt;0.001), with 1.3-fold and 1.2-fold increases observed at 10���8 mol/l, respectively. Administration of GIP analogues (25 nmol/kg body weight, i.p.) together with glucose (18 mmol/kg) in (ob/ob) mice lowered (p&lt;0.001) individual glucose values at 60 min together with the areas under the curve for glucose compared to native GIP. This antihyperglycaemic effect was coupled to a raised (p&lt;0.001) and more prolonged insulin response after administration of Ac-GIP and pGlu-GIP (AUC, 644��54 and 576��51 ng��ml���1��min, respectively) compared with native GIP (AUC, 257��29 ng��ml���1��min).<br/><br/>Conclusion/interpretation: Ac-GIP and pGlu-GIP, show resistance to plasma dipeptidylpeptidase IV degradation, resulting in enhanced biological activity and improved antidiabetic potential in vivo, raising the possibility of their use in therapy of Type II (non-insulin-dependent) diabetes mellitus.

Role of creatine supplementation on exercise-induced cardiovascular function and oxidative stress

Many degenerative diseases are associated with increased oxidative stress. Creatine has the potential to act as an indirect and direct antioxidant; however, limited data exist to evaluate the antioxidant capabdities of creatine supplementation within in vivo human systems. This study aimed to investigate the effects of oral creatine supplementation on markers of oxidative stress and antioxidant defenses following exhaustive cycling exercise. Following preliminary testing and two additional familiarization sessions, 18 active males repeated two exhaustive incremental cycling trials (T1 and T2) separated by exactly 7 days. The subjects were assigned, in a double-blind manner, to receive either 20 g of creatine (Cr) or a placebo (P) for the 5 days preceding T2. Breath-by-breath respiratory data and heart rate were continually recorded throughout the exercise protocol and blood samples were obtained at rest (preexercise), at the end of exercise (postexercise), and the day following exercise (post24 h). Serum hypdroperoxide concentrations were elevated at postexercise by 17 +/- 5% above preexercise values (p = 0.030). However, supplementation did not influence lipid peroxidation (serum hypdroperoxide concentrations), resistance of low density lipoprotein to oxidative stress (t(1/2max) LDL oxidation) and plasma concentrations of non-enzymatic antioxidants (retinol, alpha-carotene, beta-carotene, alpha-tocopherol, gamma-tocopherol, lycopene and vitamin Q. Heart rate and oxygen uptake responses to exercise were not affected by supplementation. These findings suggest that short-term creatine supplementation does not enhance non-enzymatic antioxidant defence or protect against lipid peroxidation induced by exhaustive cycling in healthy males.

TIME-RESOLVED RESONANCE RAMAN-SPECTROSCOPY OF EXCITED SINGLET AND TRIPLET-STATES OF FREE-BASE MESO-TETRAPHENYLPORPHYRIN

Two-color time-resolved resonance Raman spectroscopy has been used to probe the lowest excited singlet (S1) and triplet (T1) states of free-base meso-tetraphenylporphyrin and meso-tetrakis(4-sulphonatophenyl)porphyrin in solution at room temperature. The spectra were recorded using 532-nm excitation pulses and time-delayed probe pulses (DELTAT = 0-30 ns, 447 and 460 nm) near lambda(max) of the S1 and T1 states. Significant shifts in frequency of the porphyrin core vibrations were observed upon excitation to either the S1 or T1 state. Several of the strongest polarized bands in the spectra of both excited states, including nu1, nu2, nu4, nu6, and phi4, are assigned, and the information they give on the differences in electron distribution in the ground, S1, and T1 states is discussed.

Political Violence and Child Adjustment: Longitudinal Tests of Sectarian Antisocial Behavior, Family Conflict, and Insecurity as Explanatory Pathways

<p>Understanding the impact of political violence on child maladjustment is a matter of international concern. Recent research has advanced a social ecological explanation for relations between political violence and child adjustment. However, conclusions are qualified by the lack of longitudinal tests. Toward examining pathways longitudinally, mothers and their adolescents (M = 12.33, SD = 1.78, at Time 1) from 2-parent families in Catholic and Protestant working class neighborhoods in Belfast, Northern Ireland, completed measures assessing multiple levels of a social ecological model. Utilizing autoregressive controls, a 3-wave longitudinal model test (T1, n = 299; T2, n = 248; T3, n = 197) supported a specific pathway linking sectarian community violence, family conflict, childrens insecurity about family relationships, and adjustment problems.</p>

THE EFFECT OF THE SULFOXIDE METABOLITE OF TRICLABENDAZOLE (FASINEX) ON THE TEGUMENT OF MATURE AND IMMATURE STAGES OF THE LIVER FLUKE, FASCIOLA-HEPATICA

The effects of the novel benzimidazole, triclabendazole (TCBZ) ('Fasinex', Ciba-Geigy), in its active sulphoxide metabolite form (TCBZ-SX), on the tegumental ultrastructure of Fasciola hepatica were determined in vitro by transmission electron microscopy (TEM), using both intact flukes and tissue-slice material. At a concentration of 15 mu g/ml, the tegument of the whole adult fluke showed ultrastructural changes only after prolonged time-periods, with vacuolation at the base of the syncytium and accumulation of T2 secretory bodies in the tegumental cells. At a concentration of 50 mu g/ml, with both whole flukes and tissue-slices, the tegument appeared extremely abnormal with accumulation of secretory bodies towards the base of the syncytium. With longer incubation times, the tegument was completely sloughed away and the tegumental cells became synthetically inactive. The tegument of the 3-week-old juvenile became progressively convoluted at the apex, while in the basal regions there was severe vacuolation. In the tegumental cells, there were accumulations of T1 secretory bodies. These results confirm TCBZ as a potent fasciolicide, being very effective in disrupting the fluke tegument. They may go some way to explain the mode of action of this important fasciolicide.