我国城乡背景下教养风格对生育价值观代际传递调节作用的研究

Intergenerational cultural transmission is one process leading to cultural continuity and the transmission of value orientations may be seen as a core issue of cultural transmission. Previous research about value transmission revealed that the effectiveness of intergenerational value transmission was influenced by parenting, and parenting’s impact on culture transmission varies according to the cultural context. Value of children (VOC) refers to the functions children serve or the needs they fulfill for parents. VOC is contained in the value system and thus we would explore whether VOC could be transmitted from generation to generation like other values and how parenting impact intergenerational VOC transmission in China. Since there are dramatic differences between Chinese urban and rural context in many aspects, we would explore the effects of the transmission belt in these two social contexts respectively. A total of 200 samples were collected and each sample contained grandmother， mother and adolescent，and the results were as follows： 1. VOC could be transmitted from generation to generation, and the transmissions from grandmothers to adolescents were less effective than the transmissions from mothers to adolescents. 2. Parenting moderated the path of VOC transmission from mothers to adolescents. Authoritarian parenting could enhance the transmission of economical and social VOC factor between generations. And authoritative parenting could enhance the transmission of emotional VOC factor between generations. 3. Authoritarian parenting had significant positive predictive effect on rural adolescents’ VOC and had no predictive effect on urban adolescents’ VOC. And authoritative parenting had significant positive predictive effect on urban adolescents’ VOC.

Quantitative Inference in a Mechanical Design Compiler

This paper presents the ideas underlying a program that takes as input a schematic of a mechanical or hydraulic power transmission system, plus specifications and a utility function, and returns catalog numbers from predefined catalogs for the optimal selection of components implementing the design. It thus provides the designer with a high level "language" in which to compose new designs, then performs some of the detailed design process for him. The program is based on a formalization of quantitative inferences about hierarchically organized sets of artifacts and operating conditions, which allows design compilation without the exhaustive enumeration of alternatives.

Calibração e validação de sensor dielétrico para estimativa de teor de água em solos do Cerrado.

2008

Influence of different neuroprotective drugs on dopamine neurotoxicity induced by 3,4-methylenedioxymethamphetamine and MPTP in mice

Introduction: Parkinson‟s disease (PD) is characterized by a chronic progressive loss of nigrostriatal dopaminergic neurons that is associated with chronic neuroinflammation. Current treatments for PD can significantly improve symptoms but do not cure the disease or slow its progression. An approach used in existing therapies is based on the inhibition of monoamine oxidase (MAO), enzyme involved in the metabolic degradation of dopamine. Although, preclinical studies showed that MAO-B inhibitors have neuroprotective activity in cellular and animal models of PD, clinical trials did not completely confirm this result. Therefore a large number of new molecules, with more potent MAO-B inhibitory activity and a possible neuroprotective effect, have been proposed to replace the pre-existing MAO-B inhibitors. The profile of the recent MAO inhibitor, SZV558, appears to be particularly interesting because of its pharmacodynamic, favorable for disease-modifying properties and its irreversible MAO-B enzyme bind. The enhancement of adult neurogenesis could be of great clinical interest in the management of neurodegenerative disorders. In line with this, the metformin, a well-known antidiabetic drug, has recently been proposed to promote neurogenesis and to have a neuroprotective effect on the neurodegenerative processes induced by the dopaminergic neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) in a mice PD model. Although, PD has multiple origins, one hypothesis is that amphetamine-related drugs may be part of the wide array of factors leading to the dopaminergic neuron degeneration that causes the disease. These hypothesis are supported by different results that showed a persistent, long-term dopaminergic toxicity induced by 3,4-methylenedioxymethamphetamine (MDMA) in mice. Moreover, the MDMA, altering the dopaminergic transmission, may affect neurogenesis and synaptogenesis. On these basis, considering that the young brain is particularly sensitive to drug-induced neurotoxicity, the consumption of MDMA during the adolescence might increase the vulnerability of dopaminergic neurons. However, the use of amphetamine-related drugs by adolescent and young people is often combined with caffeinated energy drinks in order to amplify their stimulant actions. Although caffeine use is safe, the combined treatment of caffeine and MDMA increases not only the DA release but also the microglia and astroglia activation. Aims: During my Ph.D. I studied the influence of neuroprotective drugs, such as MAO inhibitors and metformin, or substances, such as caffeine, on the neurodegenerative effects of two dopaminergic toxins, MDMA and MPTP, in mice. 1. In the first phase of my study, I evaluated the neuroprotective activity of the new MAO-B inhibitor SZV558, compared with well-known rasagiline, in a chronic mouse model of MPTP plus probenecid (MPTPp), which induces a progressive loss of nigrostriatal dopaminergic neurons. 2. Previous results showed that when MDMA is associated with caffeine, a more pronounced degeneration in adolescent compared with adult mice was observed. To better clarify the molecular mechanism at the base of the different neurotoxic effect of this drug association at different ages, I evaluated the neuronal nitric oxide synthase (nNOS) expression, which plays a critical role in the integration of dopaminergic and glutamatergic transmissions, in the CPu of adolescent or adult mice treated with MDMA, alone or in combination with caffeine. 3. Finally, I investigated the neuroprotective effect of metformin against dopaminergic neurotoxicity induced by MDMA in the CPu and SNc of adult mice. Conclusions: These results demonstrated that the dopaminergic neurodegenerative process may be induced or conditioned by environment stressors or substances which influence, through different ways, the development of neurodegenerative mechanisms. In the present study I evaluated the effects of 3 substances, known as potentially neuroprotective, in combination with two different neurotoxins that affect the nigrostriatal dopaminergic system. The SZV558 MAO-B inhibitor and the metformin protected the nigrostriatal pathway, usually affected in PD, by MPTP- and MDMA- induced neurotoxicity, respectively. On the other hand, caffeine, administrated with MDMA, showed a neurotoxic potential depending on the age of consumers, confirming the vulnerability of adolescent brain to consumption of drug and substances that affected the dopaminergic system. In conclusion, the study of neurodegenerative processes may be relevant to understand the human pharmacology, the origin and development of neurodegenerative disease and to predict the neurotoxic effect of drug abuse.

Parameterization of the main ionospheric trough in the European sector

Pryse, Sian; Kersley, L.; Malan, D.; Bishop, G. J., 'Parameterization of the main ionospheric trough in the European sector, Radio Science (2006) 41 pp.RS5S14 RAE2008

Rainfall infiltration and soil hydrological characteristics below ancient forest, planted forest, and grassland in a temperate northern climate

How rainfall infiltration rate and soil hydrological characteristics develop over time under forests of different ages in temperate regions is poorly understood. In this study, infiltration rate and soil hydrological characteristics were investigated under forests of different ages and under grassland. Soil hydraulic characteristics were measured at different scales under a 250 year old grazed grassland (GL), a six (6 yr) and 48 (48 yr) year old Scots pine (Pinus sylvestris) plantation, remnant 300 year old individual Scots pines (OT) and a 4000 year old Caledonian Forest (AF). In-situ field saturated hydraulic conductivity (Kfs) was measured and visible root:soil area was estimated from soil pits. Macroporosity, pore structure, and macropore connectivity were estimated from X-ray tomography of soil cores, and from water-release characteristics. At all scales the median values for Kfs, root fraction, macro-porosity and connectivity values tended to AF > OT > 48 yr > GL > 6 yr, indicating that infiltration rates and water storage increased with forest age. The remnant Caledonian Forest had a huge range of Kfs (12 to > 4922 mm h-1), with maximum Kfs values 7 to 15 times larger than 48-year-old Scots pine plantation, suggesting that undisturbed old forests, with high rainfall and minimal evapotranspiration in winter, may act as important areas for water storage and sinks for storm rainfall to infiltrate and transport to deeper soil layers via preferential flow. The importance of the development of soil hydrological characteristics under different aged forests is discussed.

Tectonics Inversions & Emerald Deposits

In spite of the great amount of emerald deposits throughout the world, the priorities in quality and volume of extracted rough material are the sites of Colombia (Muzo and Chivor emerald belts). This sites are know even before the Spanish conquistadores. Emeralds were extracted from Somondoco mine (today Chivor) since 1537 and from Muzo in 1567. Contrariwise to the majority of the emerald deposits of the world, which are associated with granitic rocks, the Colombian emerald deposits are associated with hydrofracturing (the main factor controlling emerald mineralization) and hydrothermal fluids, rich in beryl, chrome and vanadium, induced by a tectonic inversion of the deep Mesozoic backarc basin, which is also responsible of the majority of the petroleum systems of the foredeep and foldbelt areas (maturation of the source-rocks andcreation of structural traps). The host rocks of the emeralds are carbonaceous calsiltites (calcareous schists) rich in organic matter of Lower Cretaceous age, which are cut by calcite veins, which, often, contain emeralds, particularly when they are folded. Indeed, since long time (Cheilletz, A. and Giulliani, G., 1996) suggested a two-stage model for the formation of the Colombian emeralds : (i) Stage I is characterized by décollement planes (early compressional tectonic regime) within the carbonaceous calsiltites, hydrothermal fluid infiltration and wall-rock metasomatic alteration ; (ii) Stage II (late tectonic regime) deforms the previous veins by thrust-related folds (development of stratiform and hydraulic breccia), which are synchronous of the emerald mineralization. The resulting tectonic structures are complex fold patterns characterized by propagation anticlines with emerald veins and emerald hydraulic breccia in the apexes, as in Quipama, Tendenquema and Chivor mines. Otherwise stated, since all emerald exploitations are, presently underground, exhaustive geological and particularly structural studies are required to reduce the probability of disappointments. The color of emeralds is from light green to thick green with obvious pleochroism. They appears with different colors when observed at different angles, especially with polarized light. The emeralds from Coscuez deposits have a homogeneous intensive color and bluish tone. At Muzo deposit, the emeralds have middle or dark green color with yellowish tone. At the Chivor deposits, the emeralds have less intensive green color with slight bluish tone. The typical inclusions are albite and pyrite, as well as long bubbles with three phase-inclusions according the zones of growth and along the crystal shapes.

Securing Bulk Content Almost for Free

Content providers often consider the costs of security to be greater than the losses they might incur without it; many view "casual piracy" as their main concern. Our goal is to provide a low cost defense against such attacks while maintaining rigorous security guarantees. Our defense is integrated with and leverages fast forward error correcting codes, such as Tornado codes, which are widely used to facilitate reliable delivery of rich content. We tune one such family of codes - while preserving their original desirable properties - to guarantee that none of the original content can b e recovered whenever a key subset of encoded packets is missing. Ultimately we encrypt only these key codewords (only 4% of all transmissions), making the security overhead negligible.

PeriScope: An Active Internet Probing and Measurement API

Growing interest in inference and prediction of network characteristics is justified by its importance for a variety of network-aware applications. One widely adopted strategy to characterize network conditions relies on active, end-to-end probing of the network. Active end-to-end probing techniques differ in (1) the structural composition of the probes they use (e.g., number and size of packets, the destination of various packets, the protocols used, etc.), (2) the entity making the measurements (e.g. sender vs. receiver), and (3) the techniques used to combine measurements in order to infer specific metrics of interest. In this paper, we present Periscope: a Linux API that enables the definition of new probing structures and inference techniques from user space through a flexible interface. PeriScope requires no support from clients beyond the ability to respond to ICMP ECHO REQUESTs and is designed to minimize user/kernel crossings and to ensure various constraints (e.g., back-to-back packet transmissions, fine-grained timing measurements) We show how to use Periscope for two different probing purposes, namely the measurement of shared packet losses between pairs of endpoints and for the measurement of subpath bandwidth. Results from Internet experiments for both of these goals are also presented.

Biomethane production from food waste and organic residues

Anaerobic digestion (AD) of biodegradable waste is an environmentally and economically sustainable solution which incorporates waste treatment and energy recovery. The organic fraction of municipal solid waste (OFMSW), which comprises mostly of food waste, is highly degradable under anaerobic conditions. Biogas produced from OFMSW, when upgraded to biomethane, is recognised as one of the most sustainable renewable biofuels and can also be one of the cheapest sources of biomethane if a gate fee is associated with the substrate. OFMSW is a complex and heterogeneous material which may have widely different characteristics depending on the source of origin and collection system used. The research presented in this thesis investigates the potential energy resource from a wide range of organic waste streams through field and laboratory research on real world samples. OFMSW samples collected from a range of sources generated methane yields ranging from 75 to 160 m3 per tonne. Higher methane yields are associated with source segregated food waste from commercial catering premises as opposed to domestic sources. The inclusion of garden waste reduces the specific methane yield from household organic waste. In continuous AD trials it was found that a conventional continuously stirred tank reactor (CSTR) gave the highest specific methane yields at a moderate organic loading rate of 2 kg volatile solids (VS) m-3 digester day-1 and a hydraulic retention time of 30 days. The average specific methane yield obtained at this loading rate in continuous digestion was 560 ± 29 L CH4 kg-1 VS which exceeded the biomethane potential test result by 5%. The low carbon to nitrogen ratio (C: N <14:1) associated with canteen food waste lead to increasing concentrations of volatile fatty acids in line with high concentrations of ammonia nitrogen at higher organic loading rates. At an organic loading rate of 4 kg VS m-3day-1 the specific methane yield dropped considerably (381 L CH4 kg-1 VS), the pH rose to 8.1 and free ammonia (NH3 ) concentrations reached toxicity levels towards the end of the trial (ca. 950 mg L-1). A novel two phase AD reactor configuration consisting of a series of sequentially fed leach bed reactors connected to an upflow anaerobic sludge blanket (UASB) demonstrated a high rate of organic matter decay but resulted in lower specific methane yields (384 L CH4 kg-1 VS) than the conventional CSTR system.

Contrasting the efficiency of radiation belt losses caused by ducted and nonducted whistler-mode waves from ground-based transmitters

It has long been recognized that whistler-mode waves can be trapped in plasmaspheric whistler ducts which guide the waves. For nonguided cases these waves are said to be "nonducted", which is dominant for L < 1.6. Wave-particle interactions are affected by the wave being ducted or nonducted. In the field-aligned ducted case, first-order cyclotron resonance is dominant, whereas nonducted interactions open up a much wider range of energies through equatorial and off-equatorial resonance. There is conflicting information as to whether the most significant particle loss processes are driven by ducted or nonducted waves. In this study we use loss cone observations from the DEMETER and POES low-altitude satellites to focus on electron losses driven by powerful VLF communications transmitters. Both satellites confirm that there are well-defined enhancements in the flux of electrons in the drift loss cone due to ducted transmissions from the powerful transmitter with call sign NWC. Typically, ∼80% of DEMETER nighttime orbits to the east of NWC show electron flux enhancements in the drift loss cone, spanning a L range consistent with first-order cyclotron theory, and inconsistent with nonducted resonances. In contrast, ∼1% or less of nonducted transmissions originate from NPM-generated electron flux enhancements. While the waves originating from these two transmitters have been predicted to lead to similar levels of pitch angle scattering, we find that the enhancements from NPM are at least 50 times smaller than those from NWC. This suggests that lower-latitude, nonducted VLF waves are much less effective in driving radiation belt pitch angle scattering. Copyright 2010 by the American Geophysical Union.

Antisense Gene Silencing and Bacteriophages as Novel Disinfection Processes for Engineered Systems

The growth and proliferation of invasive bacteria in engineered systems is an ongoing problem. While there are a variety of physical and chemical processes to remove and inactivate bacterial pathogens, there are many situations in which these tools are no longer effective or appropriate for the treatment of a microbial target. For example, certain strains of bacteria are becoming resistant to commonly used disinfectants, such as chlorine and UV. Additionally, the overuse of antibiotics has contributed to the spread of antibiotic resistance, and there is concern that wastewater treatment processes are contributing to the spread of antibiotic resistant bacteria.

Due to the continually evolving nature of bacteria, it is difficult to develop methods for universal bacterial control in a wide range of engineered systems, as many of our treatment processes are static in nature. Still, invasive bacteria are present in many natural and engineered systems, where the application of broad acting disinfectants is impractical, because their use may inhibit the original desired bioprocesses. Therefore, to better control the growth of treatment resistant bacteria and to address limitations with the current disinfection processes, novel tools that are both specific and adaptable need to be developed and characterized.

In this dissertation, two possible biological disinfection processes were investigated for use in controlling invasive bacteria in engineered systems. First, antisense gene silencing, which is the specific use of oligonucleotides to silence gene expression, was investigated. This work was followed by the investigation of bacteriophages (phages), which are viruses that are specific to bacteria, in engineered systems.


For the antisense gene silencing work, a computational approach was used to quantify the number of off-targets and to determine the effects of off-targets in prokaryotic organisms. For the organisms of Escherichia coli K-12 MG1655 and Mycobacterium tuberculosis H37Rv the mean number of off-targets was found to be 15.0 + 13.2 and 38.2 + 61.4, respectively, which results in a reduction of greater than 90% of the effective oligonucleotide concentration. It was also demonstrated that there was a high variability in the number of off-targets over the length of a gene, but that on average, there was no general gene location that could be targeted to reduce off-targets. Therefore, this analysis needs to be performed for each gene in question. It was also demonstrated that the thermodynamic binding energy between the oligonucleotide and the mRNA accounted for 83% of the variation in the silencing efficiency, compared to the number of off-targets, which explained 43% of the variance of the silencing efficiency. This suggests that optimizing thermodynamic parameters must be prioritized over minimizing the number of off-targets. In conclusion for the antisense work, these results suggest that off-target hybrids can account for a greater than 90% reduction in the concentration of the silencing oligonucleotides, and that the effective concentration can be increased through the rational design of silencing targets by minimizing off-target hybrids.

Regarding the work with phages, the disinfection rates of bacteria in the presence of phages was determined. The disinfection rates of E. coli K12 MG1655 in the presence of coliphage Ec2 ranged up to 2 h-1, and were dependent on both the initial phage and bacterial concentrations. Increasing initial phage concentrations resulted in increasing disinfection rates, and generally, increasing initial bacterial concentrations resulted in increasing disinfection rates. However, disinfection rates were found to plateau at higher bacterial and phage concentrations. A multiple linear regression model was used to predict the disinfection rates as a function of the initial phage and bacterial concentrations, and this model was able to explain 93% of the variance in the disinfection rates. The disinfection rates were also modeled with a particle aggregation model. The results from these model simulations suggested that at lower phage and bacterial concentrations there are not enough collisions to support active disinfection rates, which therefore, limits the conditions and systems where phage based bacterial disinfection is possible. Additionally, the particle aggregation model over predicted the disinfection rates at higher phage and bacterial concentrations of 108 PFU/mL and 108 CFU/mL, suggesting other interactions were occurring at these higher concentrations. Overall, this work highlights the need for the development of alternative models to more accurately describe the dynamics of this system at a variety of phage and bacterial concentrations. Finally, the minimum required hydraulic residence time was calculated for a continuous stirred-tank reactor and a plug flow reactor (PFR) as a function of both the initial phage and bacterial concentrations, which suggested that phage treatment in a PFR is theoretically possible.

In addition to determining disinfection rates, the long-term bacterial growth inhibition potential was determined for a variety of phages with both Gram-negative and Gram-positive bacteria. It was determined, that on average, phages can be used to inhibit bacterial growth for up to 24 h, and that this effect was concentration dependent for various phages at specific time points. Additionally, it was found that a phage cocktail was no more effective at inhibiting bacterial growth over the long-term than the best performing phage in isolation.

Finally, for an industrial application, the use of phages to inhibit invasive Lactobacilli in ethanol fermentations was investigated. It was demonstrated that phage 8014-B2 can achieve a greater than 3-log inactivation of Lactobacillus plantarum during a 48 h fermentation. Additionally, it was shown that phages can be used to protect final product yields and maintain yeast viability. Through modeling the fermentation system with differential equations it was determined that there was a 10 h window in the beginning of the fermentation run, where the addition of phages can be used to protect final product yields, and after 20 h no additional benefit of the phage addition was observed.

In conclusion, this dissertation improved the current methods for designing antisense gene silencing targets for prokaryotic organisms, and characterized phages from an engineering perspective. First, the current design strategy for antisense targets in prokaryotic organisms was improved through the development of an algorithm that minimized the number of off-targets. For the phage work, a framework was developed to predict the disinfection rates in terms of the initial phage and bacterial concentrations. In addition, the long-term bacterial growth inhibition potential of multiple phages was determined for several bacteria. In regard to the phage application, phages were shown to protect both final product yields and yeast concentrations during fermentation. Taken together, this work suggests that the rational design of phage treatment is possible and further work is needed to expand on this foundation.

Conversion of natural forests to managed forest plantations decreases tree resistance to prolonged droughts

© 2015 Published by Elsevier B.V.Throughout the southern US, past forest management practices have replaced large areas of native forests with loblolly pine plantations and have resulted in changes in forest response to extreme weather conditions. However, uncertainty remains about the response of planted versus natural species to drought across the geographical range of these forests. Taking advantage of a cluster of unmanaged stands (85-130year-old hardwoods) and managed plantations (17-20year-old loblolly pine) in coastal and Piedmont areas of North Carolina, tree water use, cavitation resistance, whole-tree hydraulic (Ktree) and stomatal (Gs) conductances were measured in four sites covering representative forests growing in the region. We also used a hydraulic model to predict the resilience of those sites to extreme soil drying. Our objectives were to determine: (1) if Ktree and stomatal regulation in response to atmospheric and soil droughts differ between species and sites; (2) how ecosystem type, through tree water use, resistance to cavitation and rooting profiles, affects the water uptake limit that can be reached under drought; and (3) the influence of stand species composition on critical transpiration that sets a functional water uptake limit under drought conditions. The results show that across sites, water stress affected the coordination between Ktree and Gs. As soil water content dropped below 20% relative extractable water, Ktree declined faster and thus explained the decrease in Gs and in its sensitivity to vapor pressure deficit. Compared to branches, the capability of roots to resist high xylem tension has a great impact on tree-level water use and ultimately had important implications for pine plantations resistance to future summer droughts. Model simulations revealed that the decline in Ktree due to xylem cavitation aggravated the effects of soil drying on tree transpiration. The critical transpiration rate (Ecrit), which corresponds to the maximum rate at which transpiration begins to level off to prevent irreversible hydraulic failure, was higher in managed forest plantations than in their unmanaged counterparts. However, even with this higher Ecrit, the pine plantations operated very close to their critical leaf water potentials (i.e. to their permissible water potentials without total hydraulic failure), suggesting that intensively managed plantations are more drought-sensitive and can withstand less severe drought than natural forests.

Deficiencias hídricas inducidas en un cultivo de maíz : efectos sobre las propiedades hidráulicas del suelo

p.203-210

Conductividad hidráulica saturada de perlita para distintos tiempos de uso en cultivo de rosas bajo cubierta

p.227-232