Pioneer (United States)

Abstract This paper presents a software environment for processing, segmenting, quantifying, representing and manipulating digital microstructure data. The paper discusses the approach to building a generalized representation strategy for digital microstructures and the barriers encountered when trying to integrate a set of existing software tools to create an expandable codebase.

A new infrared ratio, α1372 cm. −1/α2900 cm. −1, is proposed for measuring crystallinity in cellulosic materials. The advantage of this ratio over others which have been used is that it can be applied to both celluloses I and II and, therefore, to samples containing a mixed lattice. Two series of samples, encompassing a wide range of crystallinity, were prepared from highly crystalline celluloses I and II. The infrared ratios of these samples were compared with crystallinity values from x-ray diffractograms and density measurements, and with accessibility data from moisture sorption. It was shown that the new infrared ratio ranks samples of both lattice types, as well as partly mercerized cottons, in the same order as do x-ray, density, and moisture sorption data. The correlation of the new infrared ratio with accessibility, derived from moisture regain, is better than with crystallinities from either x-ray or density measurements. Reasons for this are suggested.

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Core Ideas A community effort is needed to move soil modeling forward. Establishing an international soil modeling consortium is key in this respect. There is a need to better integrate existing knowledge in soil models. Integration of data and models is a key challenge in soil modeling. The remarkable complexity of soil and its importance to a wide range of ecosystem services presents major challenges to the modeling of soil processes. Although major progress in soil models has occurred in the last decades, models of soil processes remain disjointed between disciplines or ecosystem services, with considerable uncertainty remaining in the quality of predictions and several challenges that remain yet to be addressed. First, there is a need to improve exchange of knowledge and experience among the different disciplines in soil science and to reach out to other Earth science communities. Second, the community needs to develop a new generation of soil models based on a systemic approach comprising relevant physical, chemical, and biological processes to address critical knowledge gaps in our understanding of soil processes and their interactions. Overcoming these challenges will facilitate exchanges between soil modeling and climate, plant, and social science modeling communities. It will allow us to contribute to preserve and improve our assessment of ecosystem services and advance our understanding of climate‐change feedback mechanisms, among others, thereby facilitating and strengthening communication among scientific disciplines and society. We review the role of modeling soil processes in quantifying key soil processes that shape ecosystem services, with a focus on provisioning and regulating services. We then identify key challenges in modeling soil processes, including the systematic incorporation of heterogeneity and uncertainty, the integration of data and models, and strategies for effective integration of knowledge on physical, chemical, and biological soil processes. We discuss how the soil modeling community could best interface with modern modeling activities in other disciplines, such as climate, ecology, and plant research, and how to weave novel observation and measurement techniques into soil models. We propose the establishment of an international soil modeling consortium to coherently advance soil modeling activities and foster communication with other Earth science disciplines. Such a consortium should promote soil modeling platforms and data repository for model development, calibration and intercomparison essential for addressing contemporary challenges.

The infrared spectra of highly crystalline samples of cellulose containing the lattice types I, II, and III were compared with one another and with the spectrum of amorphous cellulose in the 850–1500 cm.−1 region. The spectra of cellulose II and of amorphous cellulose showed interesting similarities at 1420, 893–897, and 1111 cm.−1, three bands which others have used to follow changes in crystallinity and lattice type because the spectrum of cellulose I differs distinctly at these points from that of amorphous cellulose or cellulose II. The similarity between amorphous cellulose and cellulose II prevents the use of these bands for crystallinity determination in samples with mixed lattice types–for instance, partly mercerized cotton. An explanation is offered for the resemblance of the two spectra, based on the hypothesis that a rearrangement of intramolecular hydrogen bonds, tending to stabilize a different conformation of the cellulose chain, occurs upon destruction of the native cellulose I crystal lattice.

New developments in ecotoxicology are changing the way pesticides and other toxicants are evaluated. An emphasis on life histories and population fitness through the use of demography, other measures of population growth rate, field studies, and modeling are being exploited to derive better estimates of pesticide impacts on both target and nontarget species than traditional lethal dose estimates. We review the state of the art in demographic toxicology, an approach to the evaluation of toxicity that uses life history parameters and other measures of population growth rate. A review of the literature revealed that 75 studies on the use of demography and similar measures of population growth rate in toxicology have been published since 1962. Of these 75 studies, the majority involved arthropods. Recent evaluations have indicated that ecotoxicological analysis based on population growth rate results in more accurate assessments of the impacts of pesticides and other toxicants because measures of population growth rate combine lethal and sublethal effects, which lethal dose/concentration estimates (LD/LC50) cannot do. We contend that to advance our knowledge of toxicant impacts on arthropods, the population growth rate approach should be widely adopted.

We must mine the biodiversity in seed banks to help to overcome food shortages, urge Susan McCouch and colleagues.

Abstract If a solution of a fast‐reacting diacid halide in a water‐immiscible solvent is brought together with an aqueous solution of a diamine without stirring, a thin film of high polymer is formed at once at the interface. Polyurethanes and polyamides in particular form tough films which can be grasped and pulled continuously from the interface as a folded rope of film. This unstirred interfacial polycondensation not only provides a dramatic demonstration of polymer formation but has permitted the observation of polymerization behavior and the study of the effects of many variables upon the process. The polymer‐forming reactions proceed by nucleophilic displacement, and many have rate constants of at least 10 2 –10 4 1. mole −1 sec. −1 . Polymers derived from diamines were found to form in the organic solvent phase. Therefore the rate of polymer formation is controlled by the transfer of diamine from the aqueous phase. It is believed that the liquid interface does not have any beneficial orienting effect on the reactants but that it provides for the regulated flow of one reactant into an excess of the other. Furthermore, the aqueous phase provides for the removal of the interfering byproduct, hydrogen halide, from the polymerization site. Some of the interrelated variables which have been studied and which are discussed in relation to the physical mechanism are the solvent sensitivity of the polymer, partition coefficients of the reactants, reactant concentration, duration of the polymerization, and the addition of monofunctional reactants, detergents, and salts. The formation of polyphenyl esters is discussed briefly.

BACKGROUND: Engineered iron nanoparticles are being explored for the development of biomedical applications and many other industry purposes. However, to date little is known concerning the precise mechanisms of translocation of iron nanoparticles into targeted tissues and organs from blood circulation, as well as the underlying implications of potential harmful health effects in human. RESULTS: The confocal microscopy imaging analysis demonstrates that exposure to engineered iron nanoparticles induces an increase in cell permeability in human microvascular endothelial cells. Our studies further reveal iron nanoparticles enhance the permeability through the production of reactive oxygen species (ROS) and the stabilization of microtubules. We also showed Akt/GSK-3beta signaling pathways are involved in iron nanoparticle-induced cell permeability. The inhibition of ROS demonstrate ROS play a major role in regulating Akt/GSK-3beta - mediated cell permeability upon iron nanoparticle exposure. These results provide new insights into the bioreactivity of engineered iron nanoparticles which can inform potential applications in medical imaging or drug delivery. CONCLUSION: Our results indicate that exposure to iron nanoparticles induces an increase in endothelial cell permeability through ROS oxidative stress-modulated microtubule remodeling. The findings from this study provide new understandings on the effects of nanoparticles on vascular transport of macromolecules and drugs.

For the foreseeable future, plant breeding methodology will continue to unfold as a practical application of the scaling of quantitative biology. These efforts to increase the effective scale of breeding programs will focus on the immediate and long-term needs of society. The foundations of the quantitative dimension will be integration of quantitative genetics, statistics, gene-to-phenotype knowledge of traits embedded within crop growth and development models. The integration will be enabled by advances in quantitative genetics methodology and computer simulation. The foundations of the biology dimension will be integrated experimental and functional gene-to-phenotype modelling approaches that advance our understanding of functional germplasm diversity, and gene-to-phenotype trait relationships for the native and transgenic variation utilised in agricultural crops. The trait genetic knowledge created will span scales of biology, extending from molecular genetics to multi-trait phenotypes embedded within evolving genotype–environment systems. The outcomes sought and successes achieved by plant breeding will be measured in terms of sustainable improvements in agricultural production of food, feed, fibre, biofuels and other desirable plant products that meet the needs of society. In this review, examples will be drawn primarily from our experience gained through commercial maize breeding. Implications for other crops, in both the private and public sectors, will be discussed.

Mandels, Mary (Quartermaster Research and Engineering Center, Natick, Mass.), Fredrick W. Parrish, and Elwyn T. Reese. Sophorose as an inducer of cellulase in Trichoderma viride. J. Bacteriol. 83:400-408. 1962.-The impurity in glucose responsible for cellulase induction in Trichoderma viride QM 6a has been isolated and characterized as sophorose (2-O-beta-d-glucopyranosyl-d-glucose). It is present at 0.0058% in reagent grade glucose. Sophorose is a very powerful inducer of cellulase for Trichoderma viride, being 2500 times as active as cellobiose. Modifications of sophorose, such as reduction or glycoside formation, destroy its inducing ability. The high activity of sophorose as an inducer is specific for T. viride.

Cellular senescence is an essentially irreversible arrest of cell proliferation coupled to a complex senescence-associated secretory phenotype (SASP). The senescence arrest prevents the development of cancer, and the SASP can promote tissue repair. Recent data suggest that the prolonged presence of senescent cells, and especially the SASP, could be deleterious, and their beneficial effects early in life can become maladaptive such that they drive aging phenotypes and pathologies late in life. It is therefore important to develop strategies to eliminate senescent cells. There are currently under development or approved several immune cell-based therapies for cancer, which could be redesigned to target senescent cells. This review focuses on this possible use of immune cells and discusses how current cell-based therapies could be used for senescent cell removal.

The fields of machining learning and artificial intelligence are rapidly expanding, impacting nearly every technological aspect of society. Many thousands of published manuscripts report advances over the last 5 years or less. Yet materials and structures engineering practitioners are slow to engage with these advancements. Perhaps the recent advances that are driving other technical fields are not sufficiently distinguished from long-known informatics methods for materials, thereby masking their likely impact to the materials, processes, and structures engineering (MPSE). Alternatively, the diverse nature and limited availability of relevant materials data pose obstacles to machine-learning implementation. The glimpse captured in this overview is intended to draw focus to selected distinguishing advances, and to show that there are opportunities for these new technologies to have transformational impacts on MPSE. Further, there are opportunities for the MPSE fields to contribute understanding to the emerging machine-learning tools from a physics basis. We suggest that there is an immediate need to expand the use of these new tools throughout MPSE, and to begin the transformation of engineering education that is necessary for ongoing adoption of the methods.

Abstract Mulches provide aesthetic, economic and environmental benefits to urban landscapes. Mulching is especially useful in the establishment of trees in landscapes that receive minimal care, such as restoration sites. In general, mulches improve soil health, creating healthy populations of plants and associated animals. These biodiverse, stable landscapes are more resistant to stress, are more aesthetically pleasing, require fewer applications of pesticides and fertilizers, and are ultimately more sustainable than those without mulch cover. All mulches are not created equally, however, and this review compares the costs and benefits of landscape mulches as reported in the scientific literature. It also presents real and perceived problems associated with various landscape mulches.

Abstract Winter cover crops may increase soil organic carbon (SOC) levels or reduce their rate of depletion. Selection of appropriate cover crops to increase SOC requires an adequate knowledge of the quality and quantity of plant biomass produced and its rate of decomposition in soil. This study examined the SOC and carbohydrate concentrations in soil as affected by several leguminous and nonleguminous cover crops after 6 yr of a corn ( Zea mays L.) cover crop double cropping system in a temperate, humid region. The vegetation in the control treatment without cover crops was primarily shepherd's‐purse [ Capsella bursa‐pastoris (L.) Medikus]. The cover crops had a variable effect on SOC and soil carbohydrate concentrations due to a significant difference in total organic C and carbohydrate produced by the cover crops. The buried bag technique showed that the biomass C from the aboveground biomass of the cover crops decomposed rapidly in the soil with a half‐life averaging 30.9 ± 9.4 (SD) d in 1992 and 55.2 ± 7.8 (SD) d in 1993. The decomposition of carbohydrate in the aboveground biomass in the soil was also rapid with an average half‐life of 40.0 ± 13.1 (SD) d in 1992 and 50.5 ± 11.8 (SD) d in 1993. The overriding cover crop effect on SOC and carbohydrate was due to the magnitude of the C inputs from the cover crops. With more than 4 Mg ha −1 of top biomass, cereal rye ( Secale cereale L.) and annual ryegrass ( Lolium multiflorum Lam.) were better suited as winter cover crops for building SOC levels in this region than Austrian winter pea ( Lathyrus hirsutus L.), hairy vetch ( Vicia villosa Roth), and canola ( Brassica napus L.).

Cellulase is an adaptive enzyme in fungi. The inducing substrate, cellulose, is insoluble. How then does the induction occur? It is possible that soluble products of enzyme action are the natural inducers of the enzymes that attack insoluble substrates. This theory assumes that small amounts of the inducible en-zymes are produced even in the absence of in-ducer. When substrate is present it is hydrolyzed, the soluble products then enter the cell and in-duce more enzyme. Examples of products acting as inducers of polysaccharases have been cited in a previous paper (AMandels and Reese, 1957), and cellobiose can act as an inducei of cellulase (Mandels and Reese, 1957; Talboys, 1958). How-

Abstract Evaluations of porosity relevant to hydrocarbon storage capacity in kerogen-rich mudrocks (i.e., source rocks) have thus far been plagued with ambiguity, in large part because conventional core and petrophysical techniques were not designed for this rock type. The growing recognition of an intraparticle organic nanopore system that is related to thermal maturity is beginning to clarify this ambiguity. This mode of porosity likely evolved with the thermal transformation of labile kerogen and probably neither depends nor interacts (except perhaps chemically) with previously assumed “matrix” or “mineral” porosity that is dominated by bound water, and that may be largely irrelevant to hydrocarbon storage capacity in these rocks. To address this newly recognized and important nonmatrix kerogen pore system, that is arguably the dominant hydrocarbon storage and mobility network in these rocks, we introduce a relatively simple kinetic model that describes porosity development within kerogen as a function of thermal maturation. Kerogen porosity development is estimated within the upper Albian Mowry Shale in the Powder River Basin of Wyoming to illustrate the approach. Relevant storage capacity is considered to have evolved with thermal decomposition of organic matter during catagenesis, where we estimate that kerogen porosity does not typically exceed 3% of bulk rock volume. Modeled oil-in-place estimates are comparable to residual oil estimates from pyrolysis data (S1) at lower maturities, but exceed pyrolytic S1 yields at higher maturities. We hypothesize, therefore, that a subsurface kinetic porosity model might represent a means to account for S1 losses at surface conditions and to circumvent difficulties surrounding estimations of expulsion efficiencies that are inherent to more traditional mass balance calculations.

Gendicine (recombinant human p53 adenovirus), developed by Shenzhen SiBiono GeneTech Co. Ltd., was approved in 2003 by the China Food and Drug Administration (CFDA) as a first-in-class gene therapy product to treat head and neck cancer, and entered the commercial market in 2004. Gendicine is a biological therapy that is delivered via minimally invasive intratumoral injection, as well as by intracavity or intravascular infusion. The wild-type (wt) p53 protein expressed by Gendicine-transduced cells is a tumor suppressor that is activated by cellular stress, and mediates cell-cycle arrest and DNA repair, or induces apoptosis, senescence, and/or autophagy, depending upon cellular stress conditions. Based on 12 years of commercial use in >30,000 patients, and >30 published clinical studies, Gendicine has exhibited an exemplary safety record, and when combined with chemotherapy and radiotherapy has demonstrated significantly higher response rates than for standard therapies alone. In addition to head and neck cancer, Gendicine has been successfully applied to treat various other cancer types and different stages of disease. Thirteen published studies that include long-term survival data showed that Gendicine combination regimens yield progression-free survival times that are significantly longer than standard therapies alone. Although the p53 gene is mutated in >50% of all human cancers, p53 mutation status did not significantly influence efficacy outcomes and long-term survival rate for Ad- p53 -treated patients. To date, Shenzhen SiBiono GeneTech has manufactured 41 batches of Gendicine in compliance with CFDA QC/QA requirements, and 169,571 vials (1.0 × 10 12 vector particles per vial) have been used to treat patients. No serious adverse events have been reported, except for vector-associated transient fever, which occurred in 50–60% of patients and persisted for only a few hours. The manufacturing accomplishments and clinical experience with Gendicine, as well as the understanding of its cellular mechanisms of action and implications, could provide valuable insights for the international gene therapy community and add valuable data to promote further developments and advancements in the gene therapy field.

Facilitated pyruvate transport across the mitochondrial inner membrane is a critical step in carbohydrate, amino acid, and lipid metabolism. We report that clinically relevant concentrations of thiazolidinediones (TZDs), a widely used class of insulin sensitizers, acutely and specifically inhibit mitochondrial pyruvate carrier (MPC) activity in a variety of cell types. Respiratory inhibition was overcome with methyl pyruvate, localizing the effect to facilitated pyruvate transport, and knockdown of either paralog, MPC1 or MPC2, decreased the EC50 for respiratory inhibition by TZDs. Acute MPC inhibition significantly enhanced glucose uptake in human skeletal muscle myocytes after 2 h. These data (i) report that clinically used TZDs inhibit the MPC, (ii) validate that MPC1 and MPC2 are obligatory components of facilitated pyruvate transport in mammalian cells, (iii) indicate that the acute effect of TZDs may be related to insulin sensitization, and (iv) establish mitochondrial pyruvate uptake as a potential therapeutic target for diseases rooted in metabolic dysfunction.

Several flavin-dependent enzymes of the mitochondrial matrix utilize NAD(+) or NADH at about the same operating redox potential as the NADH/NAD(+) pool and comprise the NADH/NAD(+) isopotential enzyme group. Complex I (specifically the flavin, site IF) is often regarded as the major source of matrix superoxide/H2O2 production at this redox potential. However, the 2-oxoglutarate dehydrogenase (OGDH), branched-chain 2-oxoacid dehydrogenase (BCKDH), and pyruvate dehydrogenase (PDH) complexes are also capable of considerable superoxide/H2O2 production. To differentiate the superoxide/H2O2-producing capacities of these different mitochondrial sites in situ, we compared the observed rates of H2O2 production over a range of different NAD(P)H reduction levels in isolated skeletal muscle mitochondria under conditions that favored superoxide/H2O2 production from complex I, the OGDH complex, the BCKDH complex, or the PDH complex. The rates from all four complexes increased at higher NAD(P)H/NAD(P)(+) ratios, although the 2-oxoacid dehydrogenase complexes produced superoxide/H2O2 at high rates only when oxidizing their specific 2-oxoacid substrates and not in the reverse reaction from NADH. At optimal conditions for each system, superoxide/H2O2 was produced by the OGDH complex at about twice the rate from the PDH complex, four times the rate from the BCKDH complex, and eight times the rate from site IF of complex I. Depending on the substrates present, the dominant sites of superoxide/H2O2 production at the level of NADH may be the OGDH and PDH complexes, but these activities may often be misattributed to complex I.