Effect of Growth Arrestment Disease on the Anatomy and Ultrastructure of Vitis vinifera L. var. sultana

The anatomical and ultrastructural changes caused by the so called Growth Arrestment Disease (G.A.D.) in Vitis vinifera L. var. sultana were investigated by means of scanning and transmitted electron microscopy as well as light microscopy. Important morphological symptoms are described. Anatomical abnormalities were found, especially in the leaves and Hower clusters of the affected vines. Heat and moisture stress may induce abnormal physiological changes, and this may give rise to G.A.D.-symptoms

First-order decay models to describe soil C-CO2 Loss after rotary tillage

Para entendimento do impacto do preparo do solo sobre as emissões de CO2 desenvolvemos e aplicamos dois modelos conceituais que são capazes de prever a emissão de CO2 do solo após seu preparo em função da emissão da parcela sem distúrbio, acrescida de uma correção devido ao preparo. Os modelos assumem que o carbono presente na matéria orgânica lábil segue uma cinética de decaimento de primeira ordem, dada pela seguinte equação: dCsoil (t) / dt = -k Csoil (t), e que a emissão de C-CO2 é proporcional a taxa de decaimento do C no solo, onde Csolo(t) é a quantidade de carbono lábil disponível no tempo (t) e k é a constante de decaimento (tempo-1). Duas suposições foram testadas para determinação das emissões após o preparo do solo (Fp): a constante de decaimento do carbono lábil do solo (k) antes e após o preparo é igual (Modelo 1) ou desigual (Modelo 2). Conseqüentemente, a relação entre os fluxos de C das parcelas sem distúrbio (F SD) e onde o preparo do solo foi conduzido (F P) são dadas por: F P = F SD + a1 e-a2t (modelo 1) e F P = a3 F SD e-a4t (modelo 2), onde t é o tempo após o preparo. Fluxos de CO2 previstos e observados relevam um bom ajuste dos resultados com coeficiente de determinação (R²) tão alto quanto 0,91. O modelo 2 produz um ajuste ligeiramente superior quando comparado com o outro modelo. A velocidade das pás da enxada rotativa foi relacionada a um aumento na quantidade de carbono lábil e nas modificações do tempo de residência médio do carbono lábil do solo após preparo. A vantagem desta metodologia é que a variabilidade temporal das emissões induzidas pelo preparo do solo pode ser descrita a partir de uma função analítica simples, que inclui a emissão da parcela sem distúrbio e um termo exponencial modulado por parâmetros dependentes do preparo e de condições ambientais onde o experimento foi conduzido.To further understand the impact of tillage on CO2 emission, the applicability of two conceptual models was tested, which describe the CO2 emission after tillage as a function of the non-tilled emission plus a correction due to the tillage disturbance. Models assume that C in readily decomposable organic matter follows a first-order reaction kinetics equation as: dCsoil (t) / dt = -k Csoil (t), and that soil C-CO2 emission is proportional to the C decay rate in soil, where Csoil(t) is the available labile soil C (g m-2) at any time (t) and k is the decay constant (time-1). Two possible assumptions were tested to determine the tilled (F T) fluxes: the decay constants (k) of labile soil C before and after tillage are different (Model 1) or not (Model 2). Accordingly, C flux relationships between non-tilled (F NT) and tilled (F T) conditions are given by: F T = F NT + a1 e-a2t (model 1) and F T = a3 F NT e-a4t (model 2), where t is time after tillage. Predicted and observed CO2 fluxes presented good agreement based on the coefficient of determination (R² = 0.91). Model comparison revealed a slightly improved statistical fit of model 2, where all C pools are assigned with the same k constant. Rotary speed was related to increases in the amount of labile C available and to changes of the mean resident labile C pool available after tillage. This approach allows describing the temporal variability of tillage-induced emissions by a simple analytical function, including non-tilled emission plus an exponential term modulated by tillage and environmentally dependent parameters

Geochemistry of As-, F- and B-bearing waters in and around San Antonio de los Cobres, Argentina, and implications for drinking and irrigation water quality

Spring, stream and tap waters from in and around San Antonio de los Cobres, Salta, Argentina, were sampled to characterize their geochemical signatures, and to determine whether they pose a threat to human health and crops. The spring waters are typical of geothermal areas world-wide, in that they are Na-Cl waters with high concentrations of Astot, As(III), Li, B, HCO3, F and SiO2 (up to 9.49, 8.92, 13.1, 56.6, 1250, 7.30 and 57.2 mg L-1, respectively), and result from mixing of deep Na-Cl brines and meteoric HCO3-rich waters. Springs close to the town of San Antonio have higher concentrations of all elements, and are generally cooler, than springs in the Baños de Agua Caliente. Spring water chemistry is a result of mixing of deep Na-Cl brines and meteoric HCO3 waters. Stream waters are also Na-Cl type, and receive large inputs of all elements from the springs near San Antonio, but concentrations decrease downstream through the town of San Antonio due to mineral precipitation. The spring that is used as a drinking water source, and other springs in the area, have As, F and B concentrations in excess of WHO and Argentinian drinking water guidelines. Evaluation of the waters for irrigation purposes suggests that their high salinities and B concentrations may adversely affect crops. The waters may be improved for drinking and irrigation by dilution with cleaner meteoric waters, mineral precipitation or by use of commercial filters. Such recommendations could also be followed by other settlements that draw drinking and irrigation waters from geothermal sources

New light on old fingermarks: The detection of historic latent fingermarks on old paper documents using 1,2-indanedione/zinc

This study explores trends in the effectiveness of 1,2-indandione/zinc chloride (IND/Zn) for visualizing latent fingermarks on paper substrates of various ages. Preliminary investigation of contemporaneous documents showed that high quality fingermarks could be deposited through incidental handling, although smudging and overlapping were evident. IND/Zn was then applied to incidentally handled documents up to 80 years old and successfully developed potentially identifiable fingermarks, significantly increasing the established timescale for fingermark detection with amino acid sensitive reagents. The results indicate that IND/Zn remains effective over longer periods than has been previously demonstrated, although a comparison between documents of different ages suggest that progressive diffusion of the target amino acids occurs over time, affecting the proportion of potentially identifiable marks. The findings of this study reinforce the applicability of IND/Zn for the detection of historic latent fingermarks on old paper documents

Causal hierarchy within the thalamo-cortical network in spike and wave discharges

Background: Generalised spike wave (GSW) discharges are the electroencephalographic (EEG) hallmark of absence seizures, clinically characterised by a transitory interruption of ongoing activities and impaired consciousness, occurring during states of reduced awareness. Several theories have been proposed to explain the pathophysiology of GSW discharges and the role of thalamus and cortex as generators. In this work we extend the existing theories by hypothesizing a role for the precuneus, a brain region neglected in previous works on GSW generation but already known to be linked to consciousness and awareness. We analysed fMRI data using dynamic causal modelling (DCM) to investigate the effective connectivity between precuneus, thalamus and prefrontal cortex in patients with GSW discharges. Methodology and Principal Findings: We analysed fMRI data from seven patients affected by Idiopathic Generalized Epilepsy (IGE) with frequent GSW discharges and significant GSW-correlated haemodynamic signal changes in the thalamus, the prefrontal cortex and the precuneus. Using DCM we assessed their effective connectivity, i.e. which region drives another region. Three dynamic causal models were constructed: GSW was modelled as autonomous input to the thalamus (model A), ventromedial prefrontal cortex (model B), and precuneus (model C). Bayesian model comparison revealed Model C (GSW as autonomous input to precuneus), to be the best in 5 patients while model A prevailed in two cases. At the group level model C dominated and at the population-level the p value of model C was ∼1. Conclusion: Our results provide strong evidence that activity in the precuneus gates GSW discharges in the thalamo-(fronto) cortical network. This study is the first demonstration of a causal link between haemodynamic changes in the precuneus - an index of awareness - and the occurrence of pathological discharges in epilepsy. © 2009 Vaudano et al

Facing Aggression: Cues Differ for Female versus Male Faces

The facial width-to-height ratio (face ratio), is a sexually dimorphic metric associated with actual aggression in men and with observers' judgements of aggression in male faces. Here, we sought to determine if observers' judgements of aggression were associated with the face ratio in female faces. In three studies, participants rated photographs of female and male faces on aggression, femininity, masculinity, attractiveness, and nurturing. In Studies 1 and 2, for female and male faces, judgements of aggression were associated with the face ratio even when other cues in the face related to masculinity were controlled statistically. Nevertheless, correlations between the face ratio and judgements of aggression were smaller for female than for male faces (F1,36 = 7.43, p = 0.01). In Study 1, there was no significant relationship between judgements of femininity and of aggression in female faces. In Study 2, the association between judgements of masculinity and aggression was weaker in female faces than for male faces in Study 1. The weaker association in female faces may be because aggression and masculinity are stereotypically male traits. Thus, in Study 3, observers rated faces on nurturing (a stereotypically female trait) and on femininity. Judgements of nurturing were associated with femininity (positively) and masculinity (negatively) ratings in both female and male faces. In summary, the perception of aggression differs in female versus male faces. The sex difference was not simply because aggression is a gendered construct; the relationships between masculinity/femininity and nurturing were similar for male and female faces even though nurturing is also a gendered construct. Masculinity and femininity ratings are not associated with aggression ratings nor with the face ratio for female faces. In contrast, all four variables are highly inter-correlated in male faces, likely because these cues in male faces serve as “honest signals”

Filaggrin inhibits generation of CD1a neolipid antigens by house dust mite-derived phospholipase.

Atopic dermatitis is a common pruritic skin disease in which barrier dysfunction and cutaneous inflammation play a role in pathogenesis. Mechanisms underlying the associated inflammation are not fully understood, and while CD1a-expressing Langerhans cells are known to be enriched within lesions, their role in clinical disease pathogenesis has not been studied. Here we observed that house dust mite (HDM) generates neolipid antigens for presentation by CD1a to T cells in the blood and skin lesions of affected individuals. HDM-responsive CD1a-reactive T cells increased in frequency after birth and showed rapid effector function, consistent with antigen-driven maturation. To define the underlying mechanisms, we analyzed HDM-challenged human skin and observed allergen-derived phospholipase (PLA2) activity in vivo. CD1a-reactive T cell activation was dependent on HDM-derived PLA2 and such cells infiltrated the skin after allergen challenge. Filaggrin insufficiency is associated with atopic dermatitis, and we observed that filaggrin inhibits PLA2 activity and inhibits CD1a-reactive PLA2-generated neolipid-specific T cell activity from skin and blood. The most widely used classification schemes of hypersensitivity, such as Gell and Coombs are predicated on the idea that non-peptide stimulants of T cells act as haptens that modify peptides or proteins. However our results point to a broader model that does not posit haptenation, but instead shows that HDM proteins generate neolipid antigens which directly activate T cells. Specifically, the data identify a pathway of atopic skin inflammation, in which house dust mite-derived phospholipase A2 generates antigenic neolipids for presentation to CD1a-reactive T cells, and define PLA2 inhibition as a function of filaggrin, supporting PLA2 inhibition as a therapeutic approach

Fried foods: a risk factor for laryngeal cancer?

The role of fried foods on laryngeal cancer risk was investigated in a case–control study from Italy and Switzerland on 527 cases and 1297 hospital controls. A significant increased risk was found for high consumption of fried meat, fish, eggs and potatoes, with odds ratios of 1.6, 3.1, 1.9 and 1.9, respectively

Paedomorphic facial expressions give dogs a selective advantage

How wolves were first domesticated is unknown. One hypothesis suggests that wolves underwent a process of self-domestication by tolerating human presence and taking advantage of scavenging possibilities. The puppy-like physical and behavioural traits seen in dogs are thought to have evolved later, as a byproduct of selection against aggression. Using speed of selection from rehoming shelters as a proxy for artificial selection, we tested whether paedomorphic features give dogs a selective advantage in their current environment. Dogs who exhibited facial expressions that enhance their neonatal appearance were preferentially selected by humans. Thus, early domestication of wolves may have occurred not only as wolf populations became tamer, but also as they exploited human preferences for paedomorphic characteristics. These findings, therefore, add to our understanding of early dog domestication as a complex co-evolutionary process