Fluid-rock interactions in the Martian meteorite North West Africa 817

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Oxygen and tissue culture affect placental gene expression

Introduction Placental explant culture is an important model for studying placental development and functions. We investigated the differences in placental gene expression in response to tissue culture, atmospheric and physiologic oxygen concentrations. Methods Placental explants were collected from normal term (38–39 weeks of gestation) placentae with no previous uterine contractile activity. Placental transcriptomic expressions were evaluated with GeneChip® Human Genome U133 Plus 2.0 arrays (Affymetrix). Results We uncovered sub-sets of genes that regulate response to stress, induction of apoptosis programmed cell death, mis-regulation of cell growth, proliferation, cell morphogenesis, tissue viability, and protection from apoptosis in cultured placental explants. We also identified a sub-set of genes with highly unstable pattern of expression after exposure to tissue culture. Tissue culture irrespective of oxygen concentration induced dichotomous increase in significant gene expression and increased enrichment of significant pathways and transcription factor targets (TFTs) including HIF1A. The effect was exacerbated by culture at atmospheric oxygen concentration, where further up-regulation of TFTs including PPARA, CEBPD, HOXA9 and down-regulated TFTs such as JUND/FOS suggest intrinsic heightened key biological and metabolic mechanisms such as glucose use, lipid biosynthesis, protein metabolism; apoptosis, inflammatory responses; and diminished trophoblast proliferation, differentiation, invasion, regeneration, and viability. Discussion These findings demonstrate that gene expression patterns differ between pre-culture and cultured explants, and the gene expression of explants cultured at atmospheric oxygen concentration favours stressed, pro-inflammatory and increased apoptotic transcriptomic response

Elevated histamine model: a protocol for an ex vivo model for in vitro study of histamine effect on placenta

Maternal plasma histamine levels in normal pregnancy are generally similar to those in non pregnant women during the first trimester, and usually decline gradually during the 2nd and 3rd trimesters (Brew and Sullivan, 2006). In some complications of pregnancy such as hyperemesis gravidarum (HG), spontaneous abortion (SA), pre-term labour (PL) and Pre-eclampsia (PE) histamine levels increase as pregnancy proceeds (Southren et al., 1966; Achari, Achari and Rao, 1971; Beaven et al., 1975), and the elevated levels of histamine may directly cause some of the features of these disorders (Brew and Sullivan, 2006). Placenta is a major source of histamine, but it also releases active diamine amine oxidase (DAO; EC 1.4.3.22) into the maternal circulation, which metabolises histamine (Kapeller-Adler, 1944; Gunther and Glick, 1967; Semeniuchenko, 1975; Granerus, Gillbrand and Wetterqvist, 1977; Purcell and Hanahoe, 1991; Brew, Lakasing and Sullivan, 2007). This breaks down the histamine released from the placenta in normal pregnancy, leading to the limited changes in maternal blood histamine. Clinically, the deported placental DAO activity in maternal blood increases a 1000 fold during normal pregnancy (Southren et al., 1966). The DAO activity rises exponentially in the first 24 weeks of normal gestation and plateaus thereafter to form a normal histamine-DAO-axis (nHDA) (Southren et al., 1966; Beaven et al., 1975; Dubois et al., 1977) (Ahlmark, 1944; Southren et al., 1966; Gunther and Glick, 1967; Weingold and Southren, 1968; Tufvesson, 1978; Beaven et al., 1975; Dubois et al., 1977). In contrast, the spontaneous exponential rise of DAO activity is abrogated from gestational week 8 onwards thus, leading to a defective Histamine-DAO-Axis (dHDA) in pregnancies that present with elevated maternal blood histamine (Southren et al., 1966; Achari, Achari and Rao, 1971; Beaven et al., 1975; Legge and Duff, 1981). Ex-vivo defective Histamine-DAO-Axis also referred to Elevated Histamine Model (EHM) was developed to mimic in vivo dHDA to study effects of histamine in human placenta. The EHM was developed by creating in vitro culture model to represent normal placentae with nHDA and complicated placentae with dHDA. In the nHDA samples, the endogenous DAO activity is maintained to eliminate endogenous production of histamine, while DAO activity is blocked with aminoguanidine in the dHDA samples to allow histamine levels to elevate during the treatment period. Aminoguanidine is a specific inhibitor of DAO enzyme activity (Tamura et al., 1989)

Placental gene expression in response to histamine and oxygen

Maternal Blood histamine level is tightly controlled in normal pregnancy. However, in specific complications of human pregnancy such as pre-eclampsia the levels of both placental and maternal blood histamine increase. Increasing blood histamine levels nonetheless, have been associated with oxidative stress, endothelial dysfunction, abnormal tissue growth, and Th1/TH2 imbalance, which are also linked to pre-eclampsia. Little is known of the molecular responses in the placenta to the prolonged exposure to increasing histamine levels in the presence of changing oxygen concentrations. We used microarray to detail the global programme of placental gene expression in response to histamine and oxygen and identified distinct classes of regulated genes underlying the molecular functions of histamine in the placenta

Don't hold my data hostage - A case for client protocol redesign

Transferring a large amount of data from a database to a client program is a surprisingly expensive operation. The time this requires can easily dominate the query execution time for large result sets. This represents a significant hurdle for external data analysis, for example when using statistical software. In this paper, we explore and analyse the result set serialization design space. We present experimental results from a large chunk of the database market and show the inefficiencies of current approaches. We then propose a columnar serialization method that improves transmission performance by an order of magnitude

Data Management for Data Science - Towards Embedded Analytics

The rise of Data Science has caused an influx of new usersin need of data management solutions. However, insteadof utilizing existing RDBMS solutions they are opting touse a stack of independent solutions for data storage andprocessing glued together by scripting languages. This is notbecause they do not need the functionality that an integratedRDBMS provides, but rather because existing RDBMS im-plementations do not cater to their use case. To solve theseissues, we propose a new class of data management systems:embedded analytical systems. These systems are tightlyintegrated with analytical tools, and provide fast and effi-cient access to the data stored within them. In this work,we describe the unique challenges and opportunities w.r.tworkloads, resilience and cooperation that are faced by thisnew class of systems and the steps we have taken towardsaddressing them in the DuckDB system

Use of induced acceleration to quantify the (de)stabilization effect of external and internal forces on postural responses

Due to the mechanical coupling between the body segments, it is impossible to see with the naked eye the causes of body movements and understand the interaction between movements of different body parts. The goal of this paper is to investigate the use of induced acceleration analysis to reveal the causes of body movements. We derive the analytical equations to calculate induced accelerations and evaluate its potential to study human postural responses to support-surface translations. We measured the kinematic and kinetic responses of a subject to sudden forward and backward translations of a moving platform. The kinematic and kinetics served as input to the induced acceleration analyses. The induced accelerations showed explicitly that the platform acceleration and deceleration contributed to the destabilization and restabilization of standing balance, respectively. Furthermore, the joint torques, coriolis and centrifugal forces caused by swinging of the arms, contributed positively to stabilization of the center of mass. It is concluded that induced acceleration analyses is a valuable tool in understanding balance responses to different kinds of perturbations and may help to identify the causes of movement in different pathologies