Cytokine-induced sleep: Neurons respond to TNF with production of chemokines and increased expression of Homer1a in vitro.

Interactions of neurons with microglia may play a dominant role in sleep regulation. TNF may exert its somnogeneic effects by promoting attraction of microglia and their processes to the vicinity of dendrites and synapses. We found TNF to stimulate neurons (i) to produce CCL2, CCL7 and CXCL10, chemokines acting on mononuclear phagocytes and (ii) to stimulate the expression of the macrophage colony stimulating factor (M-CSF/Csf1), which leads to elongation of microglia processes. TNF may also act on neurons by affecting the expression of genes essential in sleep-wake behavior. The neuronal expression of Homer1a mRNA, increases during spontaneous and enforced periods of wakefulness. Mice with a deletion of Homer1a show a reduced wakefulness with increased non-rapid eye movement (NREM) sleep during the dark period. Recently the TNF-dependent increase of NREM sleep in the dark period of mice with CD40-induced immune activation was found to be associated with decreased expression of Homer1a. In the present study we investigated the effects of TNF and IL-1β on gene expression in cultures of the neuronal cell line HT22 and cortical neurons. TNF slightly increased the expression of Homer1a and IL-1β profoundly enhanced the expression of Early growth response 2 (Egr2). The data presented here indicate that the decreased expression of Homer1a, which was found in the dark period of mice with CD40-induced increase of NREM sleep is not due to inhibitory effects of TNF and IL-1β on the expression of Homer1a in neurons.

Vulnerability of stream biota to climate change in mediterranean climate regions: a synthesis of ecological responses and conservation challenges

Freshwater species worldwide are experiencing dramatic declines partly attributable to ongoing climate change. It is expected that the future effects of climate change could be particularly severe in mediterranean climate (med-) regions, which host many endemic species already under great stress from the high level of human development. In this article, we review the climate and climate-induced changes in streams of med-regions and the responses of stream biota, focusing on both observed and anticipated ecological responses. We also discuss current knowledge gaps and conservation challenges. Expected climate alterations have already been observed in the last decades, and include: increased annual average air temperatures; decreased annual average precipitation; hydrologic alterations; and an increase in frequency, intensity and duration of extreme events, such as floods, droughts and fires. Recent observations, which are concordant with forecasts built, show stream biota of med-regions when facing climate changes tend to be displaced towards higher elevations and upper latitudes, communities tend to change their composition and homogenize, while some life-history traits seem to provide biota with resilience and resistance to adapt to the new conditions (as being short-lived, small, and resistant to low streamflow and desiccation). Nevertheless, such responses may be insufficient to cope with current and future environmental changes. Accurate forecasts of biotic changes and possible adaptations are difficult to obtain in med-regions mainly because of the difficulty of distinguishing disturbances due to natural variability from the effects of climate change, particularly regarding hydrology. Long-term studies are needed to disentangle such variability and improve knowledge regarding the ecological responses and the detection of early warning signals to climate change. Investments should focus on taxa beyond fish and macroinvertebrates, and in covering the less studied regions of Chile and South Africa. Scientists, policy makers and water managers must be involved in the climate change dialogue because the freshwater conservation concerns are huge.

Mediterranean-climate streams and rivers: geographically separated but ecologically comparable freshwater systems

Streams and rivers in mediterranean-climate regions (med-rivers in med-regions) are ecologically unique, with flow regimes reflecting precipitation patterns. Although timing of drying and flooding is predictable, seasonal and annual intensity of these events is not. Sequential flooding and drying, coupled with anthropogenic influences make these med-rivers among the most stressed riverine habitat worldwide. Med-rivers are hotspots for biodiversity in all med-regions. Species in med-rivers require different, often opposing adaptive mechanisms to survive drought and flood conditions or recover from them. Thus, metacommunities undergo seasonal differences, reflecting cycles of river fragmentation and connectivity, which also affect ecosystem functioning. River conservation and management is challenging, and trade-offs between environmental and human uses are complex, especially under future climate change scenarios. This overview of a Special Issue on med-rivers synthesizes information presented in 21 articles covering the five med-regions worldwide: Mediterranean Basin, coastal California, central Chile, Cape region of South Africa, and southwest and southern Australia. Research programs to increase basic knowledge in less-developed med-regions should be prioritized to achieve increased abilities to better manage med-rivers.

Decay of linkage disequilibrium within genes across HGDP-CEPH human samples: most population isolates do not show increased LD

Background It is well known that the pattern of linkage disequilibrium varies between human populations, with remarkable geographical stratification. Indirect association studies routinely exploit linkage disequilibrium around genes, particularly in isolated populations where it is assumed to be higher. Here, we explore both the amount and the decay of linkage disequilibrium with physical distance along 211 gene regions, most of them related to complex diseases, across 39 HGDP-CEPH population samples, focusing particularly on the populations defined as isolates. Within each gene region and population we use r2 between all possible single nucleotide polymorphism (SNP) pairs as a measure of linkage disequilibrium and focus on the proportion of SNP pairs with r2 greater than 0.8. Results Although the average r2 was found to be significantly different both between and within continental regions, a much higher proportion of r2 variance could be attributed to differences between continental regions (2.8% vs. 0.5%, respectively). Similarly, while the proportion of SNP pairs with r2 > 0.8 was significantly different across continents for all distance classes, it was generally much more homogenous within continents, except in the case of Africa and the Americas. The only isolated populations with consistently higher LD in all distance classes with respect to their continent are the Kalash (Central South Asia) and the Surui (America). Moreover, isolated populations showed only slightly higher proportions of SNP pairs with r2 > 0.8 per gene region than non-isolated populations in the same continent. Thus, the number of SNPs in isolated populations that need to be genotyped may be only slightly less than in non-isolates. Conclusion The 'isolated population' label by itself does not guarantee a greater genotyping efficiency in association studies, and properties other than increased linkage disequilibrium may make these populations interesting in genetic epidemiology.

Síntese e caracterização de perovskitas LaNi(1-x)Co xO3 como precursores de catalisadores para a conversão do metano a gás de síntese pela reforma com CO2

LaNiO3 perovskite was modified by partial substitution of nickel by cobalt in order to increase the stability and resistance to carbon deposition during the methane CO2 reforming. The results showed that a suitable combination of precipitation and calcination steps resulted in oxides with the desired structure and with important properties for application in heterogeneous catalysis. The partial substitution of Ni by Co resulted in lower rates of conversion of both the reactants, but the catalyst stability was highly increased. The LaNi0.3Co0.7O3 catalyst, calcined at 800 ºC, was the most active under the reaction conditions.

Óxidos do tipo perovskita para reação de redução de no com CO

In this work, the perovskite-type oxides LaNiO3, LaMnO3, La0,7Sr0,3NiO3 and La0,7Sr0,3MnO3 were prepared by co-precipitation and tested in the NO reduction with CO at 400 and 500 ºC for 10 h. The catalysts were characterized by X-ray diffraction, temperature programmed reduction with hydrogen, nitrogen adsorption and chemical analysis. The nonstoichiometric oxygen was quantified by temperature programmed reduction, and the catalytic tests showed that the La0,7Sr0,3MnO3 catalyst presented the higher performance for the reduction reaction of NO with CO. The partial substitution of lanthanum by strontium increased the NO conversion and the N2 yield.

pH effect on the synthesis of magnetite nanoparticles by the chemical reduction-precipitation method

This work aimed at putting in evidence the influence of the pH on the chemical nature and properties of the synthesized magnetic nanocomposites. Saturation magnetization measurements evidenced a marked difference of the magnetic behavior of samples, depending on the final pH of the solution after reaction. Magnetite and maghemite in different proportions were the main magnetic iron oxides actually identified. Synthesis with final pH between 9.7-10.6 produced nearly pure magnetite with little or no other associated iron oxide. Under other synthetic conditions, goethite also appears in proportions that depended upon the pH of the synthesis medium.

A NOVEL POLYACRYLAMIDE-BASED HYDROGEL CROSSLINKED WITH CELLULOSE ACETATE AND PREPARED BY PRECIPITATION POLYMERIZATION

The synthesis of polyacrylamide-cellulose acetate hydrogels by precipitation polymerization in acetone solution is reported herein. These hydrogels exhibit smaller swelling ratios and larger compression moduli than homo polyacrylamide hydrogels. For cellulose acetate concentrations above 20 wt.%, hydrogels with N,N'-methylenebisacrylamide as a crosslinker exhibit swelling ratios and compression moduli similar to those of the hydrogels without the crosslinker. A possible explanation for this behavior is that cellulose acetate crosslinks polyacrylamide via free-radical reaction. The hydrogels obtained without the N,N'-methylenebisacrylamide crosslinker exhibit compression moduli up to 1.7 MPa, making them suitable for tissue engineering applications such as cartilage replacement.

Natural history of celiac disease-associated antibodies and progression to overt disease in children at increased genetic risk

Background: Celiac disease is a lifelong, gluten-sensitive, autoimmune-mediated chronic enteropathy, tightly associated with risk alleles at the HLA class II genes. Aims: This study was carried out as a part of the population-based Type 1 Diabetes Prediction and Prevention (DIPP) Project. The first aim was to study the natural history of celiac disease-associated antibodies before the diagnosis of celiac disease was made. The second aim was to describe when and in which order celiac disease-associated and type 1 diabetes-associated antibodies appeared in children with genetic risk for both diseases. Subjects and Methods: Antibodies against tissue transglutaminase (TGA) and other celiac disease-associated antibodies were measured in serum samples collected at 3- to 12-month intervals of children at genetic risk for celiac disease who participated in the DIPP project. Celiac disease was confirmed by duodenal biopsy. Type 1 diabetes-associated antibodies were measured in all samples that had been collected. Overt disease was diagnosed according to World Health Organization criteria. Follow-up continued until a diagnosis of type 1 diabetes or until the end of a defined follow-up period. Results: TGA appeared in children at genetic risk for celiac disease only after the first year of life, but anti-gliadin antibodies often emerged significantly earlier, at age 6 months. The data show that spontaneous disappearance of celiac disease-associated antibodies, transient or persisting, is a common phenomenon, at least in prepubertal children. In children with genetic susceptibility to type 1 diabetes and celiac disease, celiac disease-associated antibodies usually develop earlier than the type 1 diabetes-associated antibodies. Conclusions: The transient nature of celiac disease-associated antibodies emphasizes the significance of establishing seropositivity repeatedly in screening detected celiac disease before gastroscopy and duodenal biopsy are considered and emphasized the importance of duodenal biopsy for diagnosing celiac disease.

Towards increased productivity and quality in software development using agile, lean and collaborative approaches

Dagens programvaruindustri står inför alltmer komplicerade utmaningar i en värld där programvara är nästan allstädes närvarande i våra dagliga liv. Konsumenten vill ha produkter som är pålitliga, innovativa och rika i funktionalitet, men samtidigt också förmånliga. Utmaningen för oss inom IT-industrin är att skapa mer komplexa, innovativa lösningar till en lägre kostnad. Detta är en av orsakerna till att processförbättring som forskningsområde inte har minskat i betydelse. IT-proffs ställer sig frågan: “Hur håller vi våra löften till våra kunder, samtidigt som vi minimerar vår risk och ökar vår kvalitet och produktivitet?” Inom processförbättringsområdet finns det olika tillvägagångssätt. Traditionella processförbättringsmetoder för programvara som CMMI och SPICE fokuserar på kvalitets- och riskaspekten hos förbättringsprocessen. Mer lättviktiga metoder som t.ex. lättrörliga metoder (agile methods) och Lean-metoder fokuserar på att hålla löften och förbättra produktiviteten genom att minimera slöseri inom utvecklingsprocessen. Forskningen som presenteras i denna avhandling utfördes med ett specifikt mål framför ögonen: att förbättra kostnadseffektiviteten i arbetsmetoderna utan att kompromissa med kvaliteten. Den utmaningen attackerades från tre olika vinklar. För det första förbättras arbetsmetoderna genom att man introducerar lättrörliga metoder. För det andra bibehålls kvaliteten genom att man använder mätmetoder på produktnivå. För det tredje förbättras kunskapsspridningen inom stora företag genom metoder som sätter samarbete i centrum. Rörelsen bakom lättrörliga arbetsmetoder växte fram under 90-talet som en reaktion på de orealistiska krav som den tidigare förhärskande vattenfallsmetoden ställde på IT-branschen. Programutveckling är en kreativ process och skiljer sig från annan industri i det att den största delen av det dagliga arbetet går ut på att skapa något nytt som inte har funnits tidigare. Varje programutvecklare måste vara expert på sitt område och använder en stor del av sin arbetsdag till att skapa lösningar på problem som hon aldrig tidigare har löst. Trots att detta har varit ett välkänt faktum redan i många decennier, styrs ändå många programvaruprojekt som om de vore produktionslinjer i fabriker. Ett av målen för rörelsen bakom lättrörliga metoder är att lyfta fram just denna diskrepans mellan programutvecklingens innersta natur och sättet på vilket programvaruprojekt styrs. Lättrörliga arbetsmetoder har visat sig fungera väl i de sammanhang de skapades för, dvs. små, samlokaliserade team som jobbar i nära samarbete med en engagerad kund. I andra sammanhang, och speciellt i stora, geografiskt utspridda företag, är det mera utmanande att införa lättrörliga metoder. Vi har nalkats utmaningen genom att införa lättrörliga metoder med hjälp av pilotprojekt. Detta har två klara fördelar. För det första kan man inkrementellt samla kunskap om metoderna och deras samverkan med sammanhanget i fråga. På så sätt kan man lättare utveckla och anpassa metoderna till de specifika krav som sammanhanget ställer. För det andra kan man lättare överbrygga motstånd mot förändring genom att introducera kulturella förändringar varsamt och genom att målgruppen får direkt förstahandskontakt med de nya metoderna. Relevanta mätmetoder för produkter kan hjälpa programvaruutvecklingsteam att förbättra sina arbetsmetoder. När det gäller team som jobbar med lättrörliga och Lean-metoder kan en bra uppsättning mätmetoder vara avgörande för beslutsfattandet när man prioriterar listan över uppgifter som ska göras. Vårt fokus har legat på att stöda lättrörliga och Lean-team med interna produktmätmetoder för beslutsstöd gällande så kallad omfaktorering, dvs. kontinuerlig kvalitetsförbättring av programmets kod och design. Det kan vara svårt att ta ett beslut att omfaktorera, speciellt för lättrörliga och Lean-team, eftersom de förväntas kunna rättfärdiga sina prioriteter i termer av affärsvärde. Vi föreslår ett sätt att mäta designkvaliteten hos system som har utvecklats med hjälp av det så kallade modelldrivna paradigmet. Vi konstruerar även ett sätt att integrera denna mätmetod i lättrörliga och Lean-arbetsmetoder. En viktig del av alla processförbättringsinitiativ är att sprida kunskap om den nya programvaruprocessen. Detta gäller oavsett hurdan process man försöker introducera – vare sig processen är plandriven eller lättrörlig. Vi föreslår att metoder som baserar sig på samarbete när processen skapas och vidareutvecklas är ett bra sätt att stöda kunskapsspridning på. Vi ger en översikt över författarverktyg för processer på marknaden med det förslaget i åtanke.

Recovery and refining of manganese as by-product from hydrometallurgical processes

The consumption of manganese is increasing, but huge amounts of manganese still end up in waste in hydrometallurgical processes. The recovery of manganese from multi-metal solutions at low concentrations may not be economical. In addition, poor iron control typically prevents the production of high purity manganese. Separation of iron from manganese can be done with chemical precipitation or solvent extraction methods. Combined carbonate precipitation with air oxidation is a feasible method to separate iron and manganese due to the fast kinetics, good controllability and economical reagents. In addition the leaching of manganese carbonate is easier and less acid consuming than that of hydroxide or sulfide precipitates. Selective iron removal with great efficiency from MnSO4 solution is achieved by combined oxygen or air oxidation and CaCO3 precipitation at pH > 5.8 and at a redox potential of > 200 mV. In order to avoid gypsum formation, soda ash should be used instead of limestone. In such case, however, extra attention needs to be paid on the reagents mole ratios in order to avoid manganese coprecipitation. After iron removal, pure MnSO4 solution was obtained by solvent extraction using organophosphorus reagents, di-(2-ethylhexyl)phosphoric acid (D2EHPA) and bis(2,4,4- trimethylpentyl)phosphinic acid (CYANEX 272). The Mn/Ca and Mn/Mg selectivities can be increased by decreasing the temperature from the commonly used temperatures (40 –60oC) to 5oC. The extraction order of D2EHPA (Ca before Mn) at low temperature remains unchanged but the lowering of temperature causes an increase in viscosity and slower phase separation. Of these regents, CYANEX 272 is selective for Mn over Ca and, therefore, it would be the better choice if there is Ca present in solution. A three-stage Mn extraction followed by a two-stage scrubbing and two-stage sulfuric acid stripping is an effective method of producing a very pure MnSO4 intermediate solution for further processing. From the intermediate MnSO4 some special Mn- products for ion exchange applications were synthesized and studied. Three types of octahedrally coordinated manganese oxide materials as an alternative final product for manganese were chosen for synthesis: layer structured Nabirnessite, tunnel structured Mg-todorokite and K-kryptomelane. As an alternative source of pure MnSO4 intermediate, kryptomelane was synthesized by using a synthetic hydrometallurgical tailings. The results show that the studied OMS materials adsorb selectively Cu, Ni, Cd and K in the presence of Ca and Mg. It was also found that the exchange rates were reasonably high due to the small particle dimensions. Materials are stable in the studied conditions and their maximum Cu uptake capacity was 1.3 mmol/g. Competitive uptake of metals and acid was studied using equilibrium, batch kinetic and fixed-bed measurements. The experimental data was correlated with a dynamic model, which also accounts for the dissolution of the framework manganese. Manganese oxide micro-crystals were also bound onto silica to prepare a composite material having a particle size large enough to be used in column separation experiments. The MnOx/SiO2 ratio was found to affect significantly the properties of the composite. The higher the ratio, the lower is the specific surface area, the pore volume and the pore size. On the other hand, higher amount of silica binder gives composites better mechanical properties. Birnesite and todorokite can be aggregated successfully with colloidal silica at pH 4 and with MnO2/SiO2 weight ratio of 0.7. The best gelation and drying temperature was 110oC and sufficiently strong composites were obtained by additional heat-treatment at 250oC for 2 h. The results show that silica–supported MnO2 materials can be utilized to separate copper from nickel and cadmium. The behavior of the composites can be explained reasonably well with the presented model and the parameters estimated from the data of the unsupported oxides. The metal uptake capacities of the prepared materials were quite small. For example, the final copper loading was 0.14 mmol/gMnO2. According to the results the special MnO2 materials are potential for a specific environmental application to uptake harmful metal ions.

DENDROCLIMATOLOGICAL RECONSTRUCTION OF SPRING-SUMMER PRECIPITATION FOR FAZENDA RIO GRANDE, PR, WITH SAMPLES OF Araucaria angustifolia (Bertol.) Kuntze

ABSTRACT Samples of Araucaria angustifolia were collected at Fazenda Rio Grande, Paraná, Brazil (25°39'S 49 18'O) in January 2011. The 32 samples from 8 trees were subjected to treatments following dendrochronological techniques. The cores were measured and dated using optical and computational methodology, and then standardized to obtain a growth-ring time series, which considers the 1907-2009 time range and represents Fazenda Rio Grande. Tree-ring indices were analyzed and correlated to temperature and precipitation averages from the 1961-2009 range. This procedure aimed to study and understand the influence of the local climate on the plant growth and if this influence can be quantified. A. angustifolia trees produce visible annual growth rings, and their earlywood and latewood are clearly defined. The present study shows that A. angustifolia is sensitive to climate variables (e.g., low temperatures in wintertime tend to stop the growth rate). The correlation between tree rings and monthly precipitation series showed a common trend, making it possible to estimate the seasonal rainfall behavior for the entire 1907-2009 range.

Monotonic trend and change points in southern Brazil precipitation

Scientific evidence on climate changes at global level has gained increasing interest in the scientific community in general. The impacts of climate change as well as anthropogenic actions may cause errors in hydro-agricultural projects existent in the watershed under study. This study aimed to identify the presence or absence of trend in total annual precipitation series of the watershed of the Mirim Lagoon, state of Rio Grande do Sul-RS / Brazil / Uruguay (Brazilian side) as well as to detect the period in which they occurred. For that, it was analyzed the precipitation data belonging to 14 weather stations. To detect the existence of monotonic trend and change points, it was used the nonparametric tests of Mann-Kendall and Mann-Whitney, the "t" test of Student for two samples of unpaired data (parametric), as well as the technique of progressive mean. The Weather Station 3152014 (Pelotas) presented changes in the trend in the series of annual precipitation in the period from 1953 to 2007. The methodologies that use subdivided series were more efficient in detecting change in trend when compared with the Mann-Kendall test, which uses the complete series (from 1921 to 2007).

Bartlett-Lewis of rectangular pulse modified model: estimate of parameters for simulation of precipitation in sub-hourly duration

The Bartlett-Lewis Rectangular Pulse Modified (BLPRM) model simulates the precipitous slide in the hourly and sub-hourly and has six parameters for each of the twelve months of the year. This study aimed to evaluate the behavior of precipitation series in the duration of 15 min, obtained by simulation using the model BLPRM in situations: (a) where the parameters are estimated from a combination of statistics, creating five different sets; (b) suitability of the model to generate rain. To adjust the parameters were used rain gauge records of Pelotas/RS/Brazil, which statistics were estimated - mean, variance, covariance, autocorrelation coefficient of lag 1, the proportion of dry days in the period considered. The results showed that the parameters related to the time of onset of precipitation (λ) and intensities (μx) were the most stable and the most unstable were ν parameter, related to rain duration. The BLPRM model adequately represented the mean, variance, and proportion of the dry period of the series of precipitation lasting 15 min and, the time dependence of the heights of rain, represented autocorrelation coefficient of the first retardation was statistically less simulated series suitability for the duration of 15 min.