A geometric mass-preserving redistancing scheme for the level set function

In this paper we describe and evaluate a geometric mass-preserving redistancing procedure for the level set function on general structured grids. The proposed algorithm is adapted from a recent finite element-based method and preserves the mass by means of a localized mass correction. A salient feature of the scheme is the absence of adjustable parameters. The algorithm is tested in two and three spatial dimensions and compared with the widely used partial differential equation (PDE)-based redistancing method using structured Cartesian grids. Through the use of quantitative error measures of interest in level set methods, we show that the overall performance of the proposed geometric procedure is better than PDE-based reinitialization schemes, since it is more robust with comparable accuracy. We also show that the algorithm is well-suited for the highly stretched curvilinear grids used in CFD simulations. Copyright (C) 2010 John Wiley & Sons, Ltd.

Intrinsic resistance of female hearts to an ischemic insult is abrogated in primary cardiac hypertrophy

Important sex differences in cardiovascular disease outcomes exist, including conditions of hypertrophic cardiomyopathy and cardiac ischemia. Studies of sex differences in the extent to which load-independent (primary) hypertrophy modulates the response to ischemia-reperfusion (I/R) damage have not been characterized. We have previously described a model of primary genetic cardiac hypertrophy, the hypertrophic heart rat (HHR). In this study the sex differences in HHR cardiac function and responses to I/R [compared to control normal heart rat (NHR)] were investigated ex vivo. The ventricular weight index was markedly increased in HHR female (7.82 ± 0.49 vs. 4.80 ± 0.10 mg/g; P < 0.05) and male (5.76 ± 0.22 vs. 4.62 ± 0.07 mg/g; P < 0.05) hearts. Female hearts of both strains exhibited a reduced basal contractility compared with strain-matched males [maximum first derivative of pressure (dP/dtmax): NHR, 4,036 ± 171 vs. 4,258 ± 152 mmHg/s; and HHR, 3,974 ± 160 vs. 4,540 ± 259 mmHg/s; P < 0.05]. HHR hearts were more susceptible to I/R (I = 25 min, and R = 30 min) injury than NHR hearts (decreased functional recovery, and increased lactate dehydrogenase efflux). Female NHR hearts exhibited a significantly greater recovery (dP/dtmax) post-I/R relative to male NHR (95.0 ± 12.2% vs. 60.5 ± 9.4%), a resistance to postischemic dysfunction not evident in female HHR (29.0 ± 5.6% vs. 25.9 ± 6.3%). Ventricular fibrillation was suppressed, and expression levels of Akt and ERK1/2 were selectively elevated in female NHR hearts. Thus the occurrence of load-independent primary cardiac hypertrophy undermines the intrinsic resistance of female hearts to I/R insult, with the observed abrogation of endogenous cardioprotective signaling pathways consistent with a potential mechanistic role in this loss of protection.

Angiotensin II receptor imbalance associated with neonatal cardiac growth restriction is a prelude to adult cardiac hypertrophy

The Hypertrophic Heart Rat (HHR) displays spontaneous cardiomyocyte hypertrophy in association with an apparent reduction in myocyte number in adulthood. This suggests the possibility of reduced hyperplasia or increased apoptosis during early cardiac development. The angiotensin AT1 and AT2 receptor subtypes have been implicated in both cellular growth and apoptosis, but the precise mechanisms are unclear. The aim of this study was to determine the relationship between cardiac AngII receptor expression levels and neonatal cardiomyocyte growth and apoptotic responses in the HHR compared with the Normal Heart Rat (NHR) control strain. Cardiac tissues were freshly harvested from male HHR and NHR at several developmental stages (p2 and 4, 6, 8, 12wks). HHR cardiac weight indices were considerably smaller than NHR at day 2 (4.330.19 vs 5.010.08 mg/g), but ‘caught-up’ to NHR by 4 weeks (5.100.15 vs 5.160.11 mg/g). By 12 weeks, HHR hearts were 27% larger than NHR. Tissue AT1A and AT2 mRNA expression levels were quantified by real-time RT-PCR. Relative to NHR, HHR neonatal hearts exhibited a 4.6-fold higher AT2/AT1 mRNA expression ratio. Cultured neonatal cardiomyocytes were infected with AT1A and/or AT2 receptor-expressing adenoviruses to achieve a physiological level of receptor expression (150 fmol receptor protein/mg total cell protein). In addition, to emulate receptor expression in neonatal HHR hearts, cells were co-infected with AT1A and AT2 receptors at a 4:1 ratio. Apoptosis incidence was studied by morphological analysis after 72 hours exposure to 0.1 M AngII. When infected with the AT1A receptor alone, a higher proportion of HHR myocytes appeared apoptotic than NHR (22.7 4.1% vs 1.1 0.6%, P 0.001). This implies that intrinsic differences predispose HHR cells to accentuated AT1-mediated apoptosis. Interestingly, the bax-1/bcl-2 mRNA expression ratio was significantly higher (50%) in HHR neonatal hearts. When cells were co-infected with AT1A and AT2 receptors, evidence of apoptosis in HHR cells virtually disappeared (0.4 0.1%). These findings suggest a novel capacity of AT2 receptors to counteract accentuated AT1A receptor-induced apoptosis in the HHR in early cardiac growth.

Elevated dietary sodium intake exacerbates myocardial hypertrophy associated with cardiac-specific overproduction of angiotensin II

Introduction/hypothesis
Cardiac hypertrophy is an independent risk factor predictive of cardiovascular disease and is significantly associated with morbidity and mortality. The mechanism by which angiotensin II (Ang II) and dietary sodium exert additive effects on the development of cardiac hypertrophy is unclear. The goal of this study was to evaluate the hypothesis that, where there is a genetic predisposition to Ang II-dependent hypertrophy, there is also an increased susceptibility to sodium-induced hypertrophy mediated by AT₁-receptor expression.

Methods
Diets of low sodium (LS, 0.3% w:w) and high sodium (HS, 4.0% w:w) content were fed to adult (age 25 weeks) control wild-type mice (WT) and to weeks) control wild-type mice (WT) and to transgenic mice exhibiting cardiac specific overexpression of angiotensinogen (TG). At the conclusion of a 40-day dietary treatment period, cardiac tissue weights were compared and the relative expression levels of Ang II receptor subtypes (AT_1A and AT₂) were evaluated using RT-PCR.

Results
WT and TG mice fed HS and LS diets maintained comparable weight gains during the treatment period. The normalised heart weights of TG mice were elevated compared to WT, and the extent of the increase was greater for mice maintained on the HS diet treatments (WT 12% vs. TG 41% increase in cardiac weight index). While a similar pattern of growth was observed for ventricular tissues, the atrial weight parameters demonstrated an additional significant effect of dietary sodium intake on tissue weight, independent of animal genetic type. No differences in the relative (GAPDH normalised) expression levels of AT_1A- and AT₂-receptor mRNA were observed between diet or animal genetic groups.

Conclusion
This study demonstrates that, where there is a pre-existing genetic condition of Ang II-dependent cardiac hypertrophy, the pro-growth effect of elevated dietary sodium intake is selectively augmented. In TG and WT mice, this effect was evident with a relatively short dietary treatment intervention (40 days). Evaluation of the levels of Ang II receptor mRNA further demonstrated that this differential growth response was not associated with an altered relative expression of either AT_1A- or AT₂-receptor subtypes. The cellular mechanistic bases for this specific Ang II-dietary sodium interaction remain to be elucidated.

Video testimony : the generation and transmission of trauma

My mother experienced the final part of the Second World War displaced and separated from her family and particularily her husband. (His name was on Oscar Schindler's List; her name was, and then wasn't). This dislocation from her husband was one trauma within a larger set of daily traumas. In 1997, as part of the Shoah Foundation Visual History series, my mother narrated her individualized video testimony, once again, separated from her family. This paper examines the methodologies of this video testimony in relation to two connected questions: was my mother re-traumatized by the process of providing her testemony, and by narrating and recording her video testimony, did she, unwittingly, 'transmit' her traumas, and those of her generation to my generation?

Mercury in vaccines from the Australian childhood immunization program schedule

Despite the removal of the mercury (Hg)-based preservative thimerosal from vaccines listed on the Australian Immunization Program Schedule for children, concerns remain among some researchers and parents for the safety of the present schedule, in part due to a fear of residual trace levels of Hg. The purpose of this study was to independently assess childhood vaccines for the presence of Hg. Eight vaccines administered to children under the age of 5 yr were assessed for Hg content via a DMA-80 direct mercury analyzer. Seven of the 8 vaccines contained no detectable levels of Hg (less than 1 ppb); however, 1 vaccine (Infanrix hexa) tested positive for Hg at 10 ppb. The result was confirmed and validated by retesting the original sample. Follow-up testing was conducted on three additional samples of Infanrix hexa (one from the same production lot and two from a different lot). All three tested positive for Hg (average of 9.7 ppb). Although the levels of Hg detected are substantially lower than any established exposure safety limits, the results of this study reveal that inaccuracies exist in public health messages, professional communications, and official documentation regarding Hg content in at least one childhood vaccine. In the interests of public health, it is incumbent on vaccine manufacturers and responsible agencies such as the Therapeutic Goods Administration and the Federal Department of Health and Ageing to address this issue as a matter of urgency.

Gastrointestinal microbiology in autistic spectrum disorder : a review

Cases of autism have frequently been reported in association with gastrointestinal problems. These observations have stimulated investigations into possible abnormalities of intestinal microbiota in autistic patients. The objectives of this paper were to review the possible involvement and mechanisms of gastrointestinal microbiota in autistic spectrum disorder and explain the possible role of gastrointestinal microbiota in the condition. This review addresses the possible involvement of bacteria, viruses and fungi, and their products in autism. Direct viral damage of neurons or disruption of normal neurodevelopment by immune elements such as cytokines, nitric oxide and bacterial products, including lipopolysaccharides, toxins and metabolites, have been suggested to contribute to autistic pathology. Numerous intestinal microbial abnormalities have been reported in individuals with autism. Research to date exploring possible gastrointestinal problems and infection in autism has been limited by small and heterogeneous samples, study design flaws and conflicting results. Furthermore, interventions designed to modify the intestinal microbial population of autistic patients are few and limited in their generalisation. In order to bring clarity to this field, high-quality and targeted investigations are needed to explore the role of gastrointestinal microbiology in autism. To this end, several promising avenues for future research are suggested.

Faecal microbiota of individuals with autism spectrum disorder

Many children with autistic spectrum disorders (ASDs) suffer from gastrointestinal problems such as diarrhoea, constipation and abdominal pain. Such symptoms may be due to a disruption of the indigenous gut microbiota promoting the overgrowth of potentially pathogenic micro-organisms. These observations have stimulated investigations into possible abnormalities of intestinal microbiota in autistic patients. The purpose of the present study was to determine if a relationship exists between ASD severity (mild – severe) and GI microbial populations. The faecal microbiota of 22 male and 6 female participants with ASDs (aged 7 ± 6 years) were analyzed by standard microbial culture methods and compared within-group (based on ASD severity) and with a standard laboratory reference range. Comparisons between children with mild ASD and those with moderate to severe ASD, as well as comparisons to a neurotypical control group previously reported, revealed that no significant differences appear to exist in the composition of the gut microbiota. Nevertheless, examination of each individual’s gut microbial composition showed 10 cases of unusual findings witch means 1out of 3 cases have unusual microbiota. Our data do not support consistent GI microbial abnormalities in ASD children, but the findings do suggest that aberrations may be found in a minority subset of ASD children. Further studies are required to determine the possible association between the microbiota and gastrointestinal dysfunctions in a subset of children with both ASD and gastro-intestinal problems.

Evaluation of biogenic amines in the faeces of children with and without autism by LC-MS/MS

Previous researchers have postulated that gastrointestinal bacteria may contribute to the development and maintenance of Autism Spectrum Disorders (ASD). There is evidence based on quantitative evaluation of the gastrointestinal bacterial population in ASD that this is unlikely and an alternate mechanism will be examined where the bacteria may contribute to the development of ASD via their metabolic products and the role of biogenic amines (BAs) will be investigated. In humans, BAs influence a number of physiological processes via their actions as neurotransmitters, local hormones and gastric acid secretion. Various amines have been implicated in several medical conditions such as schizophrenia and colon cancer. To date, the relationship between BAs and autism has not been explored. This study has been designed to identify differences (and/or similarities) in the level of Bas in faecal samples of autistic children (without gastrointestinal dysfunction: n = 14; with gastrointestinal dysfunction; n = 21) and their neurotypical siblings (n = 35) by LC-MS/MS. Regardless of the diagnosis, severity of ASD and gastrointestinal dysfunction there were no significant differences found between the groups. The findings suggest that BAs in the gastrointestinal tract do not play a role in the pathophysiology of gastrointestinal dysfunction associated with ASD.

Gastrointestinal microbiota in autistic spectrum disorder

In this thesis, gut bacteria of children with autism were examined. The results provided new information and a compelling picture of the gut bacteria of children with autism and gastrointestinal symptomatology. The mechanisms that underlie gut dysfunction might involve factors like stress-induced changes in gut physiology associated with autism.

Constitutive overexpression of the OsNAS gene family reveals single-gene strategies for effective iron- and zinc-biofortification of rice endosperm

Background
Rice is the primary source of food for billions of people in developing countries, yet the commonly consumed polished grain contains insufficient levels of the key micronutrients iron (Fe), zinc (Zn) and Vitamin A to meet daily dietary requirements. Experts estimate that a rice-based diet should contain 14.5 µg g−1 Fe in endosperm, the main constituent of polished grain, but breeding programs have failed to achieve even half of that value. Transgenic efforts to increase the Fe concentration of rice endosperm include expression of ferritin genes, nicotianamine synthase genes (NAS) or ferritin in conjunction with NAS genes, with results ranging from two-fold increases via single-gene approaches to six-fold increases via multi-gene approaches, yet no approach has reported 14.5 µg g−1 Fe in endosperm.

Methodology/Principal Findings
Three populations of rice were generated to constitutively overexpress OsNAS1, OsNAS2 or OsNAS3, respectively. Nicotianamine, Fe and Zn concentrations were significantly increased in unpolished grain of all three of the overexpression populations, relative to controls, with the highest concentrations in the OsNAS2 and OsNAS3 overexpression populations. Selected lines from each population had at least 10 µg g−1 Fe in polished grain and two OsNAS2 overexpression lines had 14 and 19 µg g−1 Fe in polished grain, representing up to four-fold increases in Fe concentration. Two-fold increases of Zn concentration were also observed in the OsNAS2 population. Synchrotron X-ray fluorescence spectroscopy demonstrated that OsNAS2 overexpression leads to significant enrichment of Fe and Zn in phosphorus-free regions of rice endosperm.

Conclusions
The OsNAS genes, particularly OsNAS2, show enormous potential for Fe and Zn biofortification of rice endosperm. The results demonstrate that rice cultivars overexpressing single rice OsNAS genes could provide a sustainable and genetically simple solution to Fe and Zn deficiency disorders affecting billions of people throughout the world.

Intoxicação por Trema micratha (Ulmaceae) em caprinos e bovinos.

Nos dois primeiros artigos deste estudo descrevem-se a ocorrência de duas intoxicações espontâneas por Trema micrantha em caprinos. Características clínicas e patológicas da hepatite tóxica aguda causada por Trema são comparadas com as diferentes plantas que causam hepatite tóxica aguda O terceiro artigo desse estudo descreve a intoxicação experimental por Trema micrantha em bovinos. Foram intoxicados 13 animais. Oito bovinos manifestaram sinais clínicos e seis desses morreram. Os sinais clínicos iniciavam a partir de 16 horas após a ingestão da planta. As mortes ocorriam entre 67 a 153 horas após a ingestão da planta. Os bovinos apresentavam apatia, sialorréia, fraqueza progressiva, coma e morte. A lesão mais importante foi observada no fígado, que era friável, com padrão lobular acentuado e áreas de hemorragia. Um animal apresentou edema perirrenal, rim pálido com hemorragias petequiais. Necrose massiva associada a hemorragia acentuada foi observado no fígado de cinco bovinos. Um animal apresentou necrose centrolobular. No sistema nervoso central de 5 animais foram observados edema perineuronal e perivascular com basofilia e retração de neurônios. Necrose tubular renal foi observada em 2 bovinos. Trema micrantha causou sinais clínicos com 50g/kg e morte a partir de 54g/kg de peso vivo.

Expectativa do retorno da classe de renda variável no Brasil

Este trabalho busca descobrir qual modelo (CAPM e Grinold e Kroner) é o melhor para estimar o futuro retorno do índice Bovespa, ex-ante. Não foi utilizado o índice completo, mas uma versão simplificada do índice utilizando as 25 maiores posições do índice ao longo de todos os trimestres desde 2000 até 2013. Este grupo já representava mais de 60% do índice. No final foi observado que o modelo CAPM conseguiu apresentar o melhor poder de explicação tanto na relação retorno observado e esperado, quanto nas medidas de erro absoluto. O único modelo que o Grinold e Kroner apresentaram um melhor resultado foi no erro percentual absoluto médio.