An assessment of the impact of local processes on dust lifting in martian climate models

Simulation of the lifting of dust from the planetary surface is of substantially greater importance on Mars than on Earth, due to the fundamental role that atmospheric dust plays in the former’s climate, yet the dust emission parameterisations used to date in martian global climate models (MGCMs) lag, understandably, behind their terrestrial counterparts in terms of sophistication. Recent developments in estimating surface roughness length over all martian terrains and in modelling atmospheric circulations at regional to local scales (less than O(100 km)) presents an opportunity to formulate an improved wind stress lifting parameterisation. We have upgraded the conventional scheme by including the spatially varying roughness length in the lifting parameterisation in a fully consistent manner (thereby correcting a possible underestimation of the true threshold level for wind stress lifting), and used a modification to account for deviations from neutral stability in the surface layer. Following these improvements, it is found that wind speeds at typical MGCM resolution never reach the lifting threshold at most gridpoints: winds fall particularly short in the southern midlatitudes, where mean roughness is large. Sub-grid scale variability, manifested in both the near-surface wind field and the surface roughness, is then considered, and is found to be a crucial means of bridging the gap between model winds and thresholds. Both forms of small-scale variability contribute to the formation of dust emission ‘hotspots’: areas within the model gridbox with particularly favourable conditions for lifting, namely a smooth surface combined with strong near-surface gusts. Such small-scale emission could in fact be particularly influential on Mars, due both to the intense positive radiative feedbacks that can drive storm growth and a strong hysteresis effect on saltation. By modelling this variability, dust lifting is predicted at the locations at which dust storms are frequently observed, including the flushing storm sources of Chryse and Utopia, and southern midlatitude areas from which larger storms tend to initiate, such as Hellas and Solis Planum. The seasonal cycle of emission, which includes a double-peaked structure in northern autumn and winter, also appears realistic. Significant increases to lifting rates are produced for any sensible choices of parameters controlling the sub-grid distributions used, but results are sensitive to the smallest scale of variability considered, which high-resolution modelling suggests should be O(1 km) or less. Use of such models in future will permit the use of a diagnosed (rather than prescribed) variable gustiness intensity, which should further enhance dust lifting in the southern hemisphere in particular.

Arable crop rotations under abiotic stress: a dynamic economic model

Break crops and multi-crop rotations are common in arable farm management, and the soil quality inherited from a previous crop is one of the parameters that determine the gross margin that is achieved with a given crop from a given parcel of land. In previous work we developed a dynamic economic model to calculate the potential yield and gross margin of a set of crops grown in a selection of typical rotation scenarios, and we reported use of the model to calculate coexistence costs for GM maize grown in a crop rotation. The model predicts economic effects of pest and weed pressures in monthly time steps. Validation of the model in respect of specific traits is proceeding as data from trials with novel crop varieties is published. Alongside this aspect of the validation process, we are able to incorporate data representing the economic impact of abiotic stresses on conventional crops, and then use the model to predict the cumulative gross margin achievable from a sequence of conventional crops grown at varying levels of abiotic stress. We report new progress with this aspect of model validation. In this paper, we report the further development of the model to take account of abiotic stress arising from drought, flood, heat or frost; such stresses being introduced in addition to variable pest and weed pressure. The main purpose is to assess the economic incentive for arable farmers to adopt novel crop varieties having multiple ‘stacked’ traits introduced by means of various biotechnological tools available to crop breeders.

Climate variability and human impact in South America during the last 2000 years: synthesis and perspectives from pollen records

An improved understanding of present-day climate variability and change relies on high-quality data sets from the past 2 millennia. Global efforts to model regional climate modes are in the process of being validated against, and integrated with, records of past vegetation change. For South America, however, the full potential of vegetation records for evaluating and improving climate models has hitherto not been sufficiently acknowledged due to an absence of information on the spatial and temporal coverage of study sites. This paper therefore serves as a guide to high-quality pollen records that capture environmental variability during the last 2 millennia. We identify 60 vegetation (pollen) records from across South America which satisfy geochronological requirements set out for climate modelling, and we discuss their sensitivity to the spatial signature of climate modes throughout the continent. Diverse patterns of vegetation response to climate change are observed, with more similar patterns of change in the lowlands and varying intensity and direction of responses in the highlands. Pollen records display local-scale responses to climate modes; thus, it is necessary to understand how vegetation–climate interactions might diverge under variable settings. We provide a qualitative translation from pollen metrics to climate variables. Additionally, pollen is an excellent indicator of human impact through time. We discuss evidence for human land use in pollen records and provide an overview considered useful for archaeological hypothesis testing and important in distinguishing natural from anthropogenically driven vegetation change. We stress the need for the palynological community to be more familiar with climate variability patterns to correctly attribute the potential causes of observed vegetation dynamics. This manuscript forms part of the wider LOng-Term multi-proxy climate REconstructions and Dynamics in South America – 2k initiative that provides the ideal framework for the integration of the various palaeoclimatic subdisciplines and palaeo-science, thereby jump-starting and fostering multidisciplinary research into environmental change on centennial and millennial timescales.

Cognitive emotion regulation as a mediator between posttraumatic stress symptoms and hypomanic personality within a non-clinical population

Background: There is a high prevalence of traumatic life events within individuals diagnosed with bipolar disorder. However, currently there is limited theoretical understanding of this relationship. Aims: To explore whether non-clinical symptoms of posttraumatic stress have a direct effect on the non-clinical symptoms of bipolar disorder, or whether this relationship is mediated by cognitive emotion regulation strategies. Method: A cross-sectional design within non-clinical participants completing an online survey including the Impact of Events Scale, Cognitive Emotion Regulation Questionnaire and the Hypomanic Personality Scale. Results: Posttraumatic stress symptoms were associated with hypomanic personality. Intrusive memories contributed a small but significant proportion of the variance between these two measures. Rumination of negative emotions mediated the relationship between posttraumatic stress and hypomanic personality. Conclusions: The relationship between traumatic events and an increased prevalence of bipolar disorder remains poorly understood. Further research should explore rumination as a potential target for treatment within those suffering from both posttraumatic stress and bipolar disorder.

Selective environmental stress caused by magmatic sulfur emissions from continental flood basalt eruptions

Several biotic crises during the past 300 million years have been linked to episodes of continental flood basalt volcanism, and in particular to the release of massive quantities of magmatic sulphur gas species. Flood basalt provinces were typically formed by numerous individual eruptions, each lasting years to decades. However, the environmental impact of these eruptions may have been limited by the occurrence of quiescent periods that lasted hundreds to thousands of years. Here we use a global aerosol model to quantify the sulphur-induced environmental effects of individual, decade-long flood basalt eruptions representative of the Columbia River Basalt Group, 16.5–14.5 million years ago, and the Deccan Traps, 65 million years ago. For a decade-long eruption of Deccan scale, we calculate a decadal-mean reduction in global surface temperature of 4.5 K, which would recover within 50 years after an eruption ceased unless climate feedbacks were very different in deep-time climates. Acid mists and fogs could have caused immediate damage to vegetation in some regions, but acid-sensitive land and marine ecosystems were well-buffered against volcanic sulphur deposition effects even during century-long eruptions. We conclude that magmatic sulphur from flood basalt eruptions would have caused a biotic crisis only if eruption frequencies and lava discharge rates had been high and sustained for several centuries at a time.

The impact of maternal cortisol concentrations on child arterial elasticity

Epidemiological studies suggest that glucocorticoid excess in the fetus may contribute to the pathophysiology of cardiovascular diseases in adulthood. However, the impact of maternal glucocorticoid on the cardiovascular system of the offspring has not been much explored in studies involving humans, especially in childhood. The objective of this study was to assess the influence of maternal cortisol concentrations on child arterial elasticity. One hundred and thirty pregnant women followed from 1997 to 2000, and respective children 5-7 years of age followed from 2004 to 2006 were included in the study. Maternal cortisol was determined in saliva by an enzyme immunoassay utilizing the mean concentration of nine samples of saliva. Arterial elasticity was assessed by the large artery elasticity index (LAEI; the capacitive elasticity of large arteries) by recording radial artery pulse wave, utilizing the equipment HDI/PulseWave CR-2000 Cardiovascular Profiling System (R). The nutritional status of the children was determined by the body mass index (BMI). Insulin concentration was assessed by chemiluminescence, and insulin resistance by the homeostasis model assessment. Blood glucose, total cholesterol and fractions (LDL-c and HDL-c) and triglyceride concentrations were determined by automated enzymatic methods. The association between maternal cortisol and child arterial elasticity was assessed by multivariate linear regression analysis. There was a statistically significant association between maternal cortisol and LAEI (P=0.02), controlling for birth weight, age, BMI and HDL-c of the children. This study suggests that exposure to higher glucocorticoid concentrations in the prenatal period is associated to lower arterial elasticity in childhood, an earlier cardiovascular risk marker.

A dislocation based theory for the deformation hardening behavior of DP steels : Impact of martensite content and ferrite grain size

A dislocation model, accurately describing the uniaxial plastic stress-strain behavior of dual phase (DP) steels, is proposed and the impact of martensite content and ferrite grain size in four commercially produced DP steels is analyzed. It is assumed that the plastic deformation process is localized to the ferrite. This is taken into account by introducing a non-homogeneity parameter, f(e), that specifies the volume fraction of ferrite taking active part in the plastic deformation process. It is found that the larger the martensite content the smaller the initial volume fraction of active ferrite which yields a higher initial deformation hardening rate. This explains the high energy absorbing capacity of DP steels with high volume fractions of martensite. Further, the effect of ferrite grain size strengthening in DP steels is important. The flow stress grain size sensitivity for DP steels is observed to be 7 times larger than that for single phase ferrite.

Kreativitet under stress : En studie i att vara kreativ på beställning

En grafisk designer måste kunna producera oavsett vilka förhållanden som råder. Rapporten behandlar vad korta och långa deadlines har för inverkan på denna förmåga och hur kreativiteten kan främjas vid stressiga situationer. Semistrukturerade djupintervjuer utfördes med åtta Art- och Creative directors i Gävledala-regionen för att undersöka hur de upplevde att vara kreativa under stressiga förhållanden. Resultatet visade att det generellt inte var ett problem för studiens respondenter att vara kreativa på beställning men att de inte heller följde några specifika metoder för att underlätta arbetsflödet. Det visade sig även att det snarare var arbetsbördan och mängden arbetsuppgifter som påverkade stressfaktorn än en specifik tidsram.

Performance and carcass characteristics of broiler chickens with different growth potential and submitted to heat stress

In order to evaluate the effects of broiler genotype and of heat exposure on performance, carcass characteristics, and protein and fat accretion, six hundred one-day-old male broilers were randomly assigned in a 2 x 3 factorial arrangement, according to the following factors: genetic group (selected and non-selected broilers) and pair-feeding scheme (Ad(32) - reared under heat stress and fed ad libitum; Ad(23) - reared at thermoneutrality and fed ad libitum; Pf(23) - reared at thermoneutrality and pair fed with Ad(32)), with a total of six treatments with four replicates of 25 birds each. Independent of pair-feeding scheme, selected broilers showed better feed conversion, higher carcass yield, and lower abdominal fat deposition rate. However, as compared to non-selected broilers, they reduced more intensively feed intake when heat exposed, which promoted significant breast-yield decrease, and more pronounced changes on carcass chemical composition. These findings allows concluding that, in both genetic groups, both environmental temperature and feed-intake restriction influence abdominal fat deposition rate and other carcass characteristics; however, the impact of heat exposure on broiler performance is more noticeable on the selected line.

Maternal-Fetal Outcome, Lipid Profile and Oxidative Stress of Diabetic Rats Neonatally Exposed to Streptozotocin

Background: There is no evidence about the integrated issue on glycemia, lipid profile, oxidative stress, and anomaly frequency of pregnant diabetic rats neonatally exposed to streptozotocin.Objective: Evaluating the impact of hyperglycemia in diabetic rats neonatally exposed to streptozotocin on maternal reproductive and fetal outcomes and the relationship with lipid profile and maternal oxidative stress.Material and Methods: Ten 90-day-old female Wistar rats were mated to obtain offspring. Some of these newborns received streptozotocin (70 mg/kg, i.p. - n5-STZ group) and the remainder given only citrate buffer (control group) on their day 5 of life. At adult life, these rats (n =13 animals/group) were mated and, at day 21 of pregnancy, they were killed to obtain a maternal blood samples for biochemical determinations. The gravid uterus was weighed with its contents and fetuses were analyzed.Results: At day 0 of pregnancy, glycemic means of n5-STZ rats were significantly greater compared to those of control rats, but presented fetuses classified as small for pregnancy age. The n5-STZ rats showed increased total cholesterol, triglycerides, MDA concentrations, lower SOD activity and increased frequency fetal visceral anomalies as compared to the control group.Conclusion: This study showed that the experimental model used led to mild hyperglycemia during pregnancy, although it did not lead to increased macrosomic fetus rates. The hyperglycemic maternal environment caused metabolic alterations, including increased triglyceride and total cholesterol concentrations, and elevated oxidative stress, contributing to increase fetal visceral anomalies.

Stress materno e hospitalização infantil pré-cirúrgica

O objetivo deste estudo foi a valiar o nível de stress de mães acompanhantes de crianças hospitalizadas para realização de procedimentos cirúrgicos eletivos, relacionando-o com variáveis demográficas da criança e experiência prévia no contexto. Participaram 54 mães acompanhantes de crianças hospitalizadas para realização de cirurgia eletiva. Utilizaram-se como instrumentos o Inventário de Sintomas de Stress para Adultos de Lipp e, para levantamento das variáveis da criança, um questionário elaborado para o estudo. Os resultados apontaram que 82% da amostra apresentavam stress, prevalencendo a fase de resistência e sintomas psicológicos. Observou-se relação estatisticamente significativa entre a presença de stress materno e o fato de o filho não ter experiência anterior com cirurgia (p=0,052). Por outro lado, não foram observadas diferenças estatisticamente significativas entre a presença de stress materno e a idade e gênero da criança. Conclui-se que o impacto dos procedimentos cirúrgicos acomete a criança e a família, o que deve ser levado em consideração a fim de que sejam propostas intervenções para a preparação pré-operatória.

The impact of different types of physical activity on total and regional bone mineral density in young Brazilian athletes

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Ballast water: a review of the impact on the world public health

Since the nineteenth century ships have been using ballast water (BW) for safety, stability, propulsion and maneuverability, as well as to redress loss of fuel weight and water consumption, and to maintain structural stress at acceptable levels. Ballast water has been spreading many non-native species around the globe, but little is known about the extent and potential significance of ship-mediated transfer of microorganisms. The global movements of ballast water by ships create a long-distance dispersal mechanism for human pathogens that may be important in the worldwide distribution of microorganisms, as well as for the epidemiology of waterborne diseases. Only a few studies have been carried out on this subject, most of them involving ballast water containing crustacean larvae and phytoplankton. Specialized microbiological studies on these waters are necessary to avoid a repeat of what happened in 1991, when epidemic cholera was reported in Peru and rapidly spread through Latin America and Mexico. In July of 1992, Vibrio cholerae was found in the USA and the Food and Drug Administration (FDA) determined that it came from ballast water of ships whose last port of call was in South America. In Brazil, just a few studies about the subject have been performed. An exploratory study by the Brazilian National Health Surveillance Agency (Agencia Nacional de Vigilancia Sanitaria - ANVISA) found in ballast water different microorganisms, such as fecal coliforms, Escherichia coli, Enterococcus faecalis, Clostridium perfringens, coliphages, Vibrio cholerae O1 and Vibrio cholerae non-O1. Until now, Brazil has been focusing only on organisms transported to its territory from other countries by ballast water, to avoid their establishment and dissemination in Brazilian areas. Studies that can assess the probability that water ballast carries pathogenic microorganisms are extremely important, as is the examination of ships that arrive in the country. Treatment of the human infections caused by BW exists but none is completely safe and efficient.

Differential coronary resistance microvessel remodeling between type 1 and type 2 diabetic mice: Impact of exercise training

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Oxidative stress markers and apoptosis in the prostate of diabetic rats and the influence of vitamin C treatment

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)