The purpose of this research was to determine the efficiency of a polymer biocover for the abatement of H
2
S and NH
3
emissions from an east-central Missouri swine lagoon with a total surface area ...of 7800 m
2
. The flux rate of NH
3
, H
2
S, and CH
4
was monitored continuously from two adjacent, circular (d = 66 m) control and treatment plots using a nonintrusive, micrometeorological method during three independent sampling periods that ranged between 52 and 149 hr. Abatement rates were observed to undergo a temporal acclimation event in which NH
3
abatement efficiency improved from 17 to 54% (p = <0.0001 to 0.0005) and H
2
S abatement efficiency improved from 23 to 58% (p < 0.0001) over a 3-month period. The increase in abatement efficiency for NH
3
and H
2
S over the sampling period was correlated with the development of a stable anaerobic floc layer on the bottom surface of the biocover that reduced mass transfer of NH
3
and H
2
S across the surface. Analysis of methanogenesis activity showed that the biocover enhanced the rate of anaerobic digestion by 25% when compared with the control. The biocover-enhanced anaerobic digestion process was shown to represent an effective mechanism to counteract the accumulation of methanogenic substrates in the biocovered lagoon.
Changes in temperature, CO2, and precipitation under the scenarios of climate change for the next 30 yr present a challenge to crop production. This review focuses on the impact of temperature, CO2, ...and ozone on agronomic crops and the implications for crop production. Understanding these implications for agricultural crops is critical for developing cropping systems resilient to stresses induced by climate change. There is variation among crops in their response to CO2, temperature, and precipitation changes and, with the regional differences in predicted climate, a situation is created in which the responses will be further complicated. For example, the temperature effects on soybean Glycine max (L.) Merr. could potentially cause yield reductions of 2.4% in the South but an increase of 1.7% in the Midwest. The frequency of years when temperatures exceed thresholds for damage during critical growth stages is likely to increase for some crops and regions. The increase in CO2 contributes significantly to enhanced plant growth and improved water use efficiency (WUE); however, there may be a downscaling of these positive impacts due to higher temperatures plants will experience during their growth cycle. A challenge is to understand the interactions of the changing climatic parameters because of the interactions among temperature, CO2, and precipitation on plant growth and development and also on the biotic stresses of weeds, insects, and diseases. Agronomists will have to consider the variations in temperature and precipitation as part of the production system if they are to ensure the food security required by an ever increasing population.
Risk and Systems Theory Hatfield, Adam J.; Hipel, Keith W.
Risk analysis,
December 2002, Volume:
22, Issue:
6
Journal Article
Peer reviewed
The last few decades have seen increasingly widespread use of risk assessment and management techniques as aids in making complex decisions. However, despite the progress that has been made in risk ...science, there still remain numerous examples of risk‐based decisions and conclusions that have caused great controversy. In particular, there is a great deal of debate surrounding risk assessment: the role of values and ethics and other extra‐scientific factors, the efficacy of quantitative versus qualitative analysis, and the role of uncertainty and incomplete information. Many of the epistemological and methodological issues confronting risk assessment have been explored in general systems theory, where techniques exist to manage such issues. However, the use of systems theory and systems analysis tools is still not widespread in risk management. This article builds on the Alachlor risk assessment case study of Brunk, Haworth, and Lee to present a systems‐based view of the risk assessment process. The details of the case study are reviewed and the authors' original conclusions regarding the effects of extra‐scientific factors on risk assessment are discussed. Concepts from systems theory are introduced to provide a mechanism with which to illustrate these extra‐scientific effects. The role of a systems study within a risk assessment is explained, resulting in an improved view of the problem formulation process. The consequences regarding the definition of risk and its role in decision making are then explored.
The Pliocene Epoch is a focus of scientific interest as a period of sustained global warmth, with reconstructed CO2 concentrations and a continent configuration similar to modern. Numerous studies ...suggest that the Pliocene was warmer and largely wetter than today, at least in the subtropics, which contrasts with the long-term hydroclimatic response of drying conditions predicted by most climate model simulations. Two key features of Pliocene warmth established from sea surface temperature reconstructions could affect dynamic changes that influence the hydrologic cycle: (1) a weaker Pliocene zonal gradient in sea surface temperature (SST) between the western and eastern equatorial Pacific resembling El Niño-like conditions and (2) polar-amplified Pliocene warmth, supporting a weaker Equator-to-pole temperature gradient. The distribution of wet conditions in western North America and the timing of late Pliocene–Quaternary aridification offer the potential to evaluate the relative roles of these two external forcings of the climate in western North America, with broader global implications for Mediterranean-type climate (MTC) regions. We convened a virtual ICDP workshop that spanned a 2-week period in September 2021, to choose optimal drill sites and legacy cores to address the overall scientific goals, flesh out research questions, and discuss how best to answer them. A total of 56 participants from 12 countries (17 time zones), representing a wide range of disciplines, came together virtually for a series of plenary and working group sessions. We have chosen to study five basins (Butte Valley, Tule Lake, Lake Idaho, Searles Lake, and Verde Valley) that span 7 ∘ of latitude to test our hypotheses and to reconstruct the evolution of western North American hydroclimate with special focus on the time ranges of 4.5–3.5 and 3–2.5 Myr. Although individual Pliocene lake records occur in many areas of the world, the western North American basins are unique and globally significant as deep perennial freshwater Pliocene lakes latitudinally arrayed in a MTC region and are able to capture a response to Pacific forcing. We propose new drill cores from three of these basins. During the workshop, we discussed the stratigraphy and subsurface structure of each basin and revised the chronological frameworks and the basin-to-basin correlations. We also identified the best-suited proxies for hydroclimate reconstructions for each particular basin and put forward a multi-technique strategy for depth–age modeling. Reconstructions based on data from these sites will complement the SST reconstructions from global sites spanning the last 4.5 Ma and elucidate the large-scale hydrological cycle controls associated with both global warming and cooling.
CD437, a novel retinoid, causes cell cycle arrest and apoptosis in a number of cancer cells including human breast carcinoma (HBC) by utilizing an undefined retinoic acid receptor/retinoid X ...receptor-independent mechanism. To delineate mediators of CD437 signaling, we utilized a random antisense-dependent functional knockout genetic approach. We identified a cDNA that encodes ∼130-kDa HBC cell perinuclear protein (termed CARP-1). Treatments with CD437 or chemotherapeutic agent adriamycin, as well as serum deprivation of HBC cells, stimulate CARP-1 expression. Reduced levels of CARP-1 result in inhibition of apoptosis by CD437 or adriamycin, whereas increased expression of CARP-1 causes elevated levels of cyclin-dependent kinase inhibitor p21WAF1/CIP1 and apoptosis. CARP-1 interacts with 14-3-3 protein as well as causes reduced expression of cell cycle regulatory genes including c-Myc and cyclin B1. Loss of c-Myc sensitizes cells to apoptosis by CARP-1, whereas expression of c-Myc or 14-3-3 inhibits CARP-1-dependent apoptosis. Thus, apoptosis induction by CARP-1 involves sequestration of 14-3-3 and CARP-1-mediated altered expression of multiple cell cycle regulatory genes. Identification of CARP-1 as a key mediator of signaling by CD437 or adriamycin allows for delineation of pathways that, in turn, may prove beneficial for design and targeting of novel antitumor agents.
► Introduces the Agricultural Model Intercomparison and Improvement Project (AgMIP). ► Describes AgMIP Protocols for consistent research activities. ► Demonstrates AgMIP approaches using climate, ...crop, and economic model analyses. ► Wheat pilot results elucidate the relative uncertainties from crop and climate models. ► Outlines AgMIP crop-specific, regional, and global research activities.
The Agricultural Model Intercomparison and Improvement Project (AgMIP) is a major international effort linking the climate, crop, and economic modeling communities with cutting-edge information technology to produce improved crop and economic models and the next generation of climate impact projections for the agricultural sector. The goals of AgMIP are to improve substantially the characterization of world food security due to climate change and to enhance adaptation capacity in both developing and developed countries. Analyses of the agricultural impacts of climate variability and change require a transdisciplinary effort to consistently link state-of-the-art climate scenarios to crop and economic models. Crop model outputs are aggregated as inputs to regional and global economic models to determine regional vulnerabilities, changes in comparative advantage, price effects, and potential adaptation strategies in the agricultural sector. Climate, Crop Modeling, Economics, and Information Technology Team Protocols are presented to guide coordinated climate, crop modeling, economics, and information technology research activities around the world, along with AgMIP Cross-Cutting Themes that address uncertainty, aggregation and scaling, and the development of Representative Agricultural Pathways (RAPs) to enable testing of climate change adaptations in the context of other regional and global trends. The organization of research activities by geographic region and specific crops is described, along with project milestones.
Pilot results demonstrate AgMIP's role in assessing climate impacts with explicit representation of uncertainties in climate scenarios and simulations using crop and economic models. An intercomparison of wheat model simulations near Obregón, Mexico reveals inter-model differences in yield sensitivity to CO2 with model uncertainty holding approximately steady as concentrations rise, while uncertainty related to choice of crop model increases with rising temperatures. Wheat model simulations with mid-century climate scenarios project a slight decline in absolute yields that is more sensitive to selection of crop model than to global climate model, emissions scenario, or climate scenario downscaling method. A comparison of regional and national-scale economic simulations finds a large sensitivity of projected yield changes to the simulations’ resolved scales. Finally, a global economic model intercomparison example demonstrates that improvements in the understanding of agriculture futures arise from integration of the range of uncertainty in crop, climate, and economic modeling results in multi-model assessments.
Although the incidence of colon cancer increases with advancing age, reasons for this increase are not fully understood. Earlier studies have demonstrated that in Fischer-344 rats, aging is ...associated with increased crypt cell production in the colon, an event considered to be central to the initiation of carcinogenesis. Apoptosis also plays a critical role in the development and progression of colon cancer. Therefore, we have examined the age-related changes in proliferation and apoptosis in the colonic mucosa of 4–5, 12–14, and 22–24 month-old Fischer-344 rats. We have observed that proliferative activity in the colon, as assessed by proliferating cell nuclear antigen immunoreactivity, is higher (50–80%) in 12–14 and 22–24 month-old rats than in their 4–6 month-old counterparts. In contrast, the number of apoptotic cells, (as determined by TdT-mediated dUTP nick-end labeling assay) in the colonic mucosa of 12–14 and 22–24 month-old rats are considerably lower (50–60%) than in 4–6 month-old animals. These changes are accompanied by a concomitant reduction (75%) in pro-apoptotic Bak and stimulation (200%) of anti-apoptotic Bcl-xL levels. Since activation of caspases is associated with initiation and maintenance of apoptosis, we also analyzed the levels of pro and active forms of caspase-3, 8 and 9. The levels of active forms of caspase-3, 8 and 9 are found to be considerably (60–80%) lower in the colonic mucosa of 22–24 month-old rats, compared to their younger counterparts. This is accompanied by decreased cleavage of poly(ADP-ribose) polymerase, a substrate for caspases. In conclusion, our data show that aging enhances proliferation, but attenuates apoptosis in the colonic mucosa. These changes may partly be responsible for the age-related rise in colorectal cancer.
Varicella-zoster virus is considered to have one of the most stable genomes of all human herpesviruses. In 1998, we reported the unanticipated discovery of a wild-type virus that had lost an ...immunodominant B-cell epitope on the gE ectodomain (VZV-MSP); the gE escape mutant virus exhibited an unusual pattern of egress. Further studies have now documented a markedly enhanced cell-to-cell spread by the mutant virus in cell culture. This property was investigated by laser scanning confocal microscopy combined with a software program that allows the measurement of pixel intensity of the fluorescent signal. For this new application of imaging technology, the VZV immediate early protein 62 (IE 62) was selected as the fluoresceinated marker. By 48 h postinfection, the number of IE 62-positive pixels in the VZV-MSP-infected culture was nearly fourfold greater than the number of pixels in a culture infected with a low-passage laboratory strain. Titrations by infectious center assays supported the above image analysis data. Confirmatory studies in the SCID-hu mouse documented that VZV-MSP spread more rapidly than other VZV strains in human fetal skin implants. Generally, the cytopathology and vesicle formation produced by other strains at 21 days postinfection were demonstrable with VZV-MSP at 14 days. To assess whether additional genes were contributing to the unusual VZV-MSP phenotype, ∼20 kb of the VZV-MSP genome was sequenced, including ORFs 31 (gB), 37 (gH), 47, 60 (gL), 61, 62 (IE 62), 66, 67 (gI), and 68 (gE). Except for a few polymorphisms, as well as the previously discovered mutation within gE, the nucleotide sequences within most open reading frames were identical to the prototype VZV-Dumas strain. In short, VZV-MSP represents a novel variant virus with a distinguishable phenotype demonstrable in both infected cell cultures and SCID-hu mice.
A three-arm randomized phase III trial in advanced colorectal cancer patients was designed to test whether substitution of an equivalent dose of (1) l-leucovorin or (2) oral leucovorin would more ...effectively potentiate fluorouracil (5-FU) than standard intravenous (I.V.) (d,l)-leucovorin.
A total of 926 chemotherapy-naive patients participated. Patients received one of three treatments: (A) intensive-course 5-FU plus l-leucovorin with I.V. leucovorin (Immunex Corp, Seattle, WA) at 100 mg/m2 and I.V. 5-FU at 370 mg/m2; (B) intensive-course 5-FU plus oral (d,l)-leucovorin with oral leucovarin at 125 mg/m2 on hours 0, 1, 2, and 3 (total dose, 500 mg/m2) followed by 5-FU 370 mg/m2 on hour 4; or (C) intensive-course 5-FU plus I.V. (d,l)-leucovorin with I.V. leucovorin 200 mg/m2 and 5-FU 370 mg/m2. Drugs were administered daily for 5 consecutive days. Courses were repeated at 4 and 8 weeks, and every 5 weeks thereafter. Dosage was reduced for neutropenia, thrombocytopenia, diarrhea, stomatitis, and dermatitis.
Of 926 eligible patients, 756 have died. The overall response rate for patients with measurable disease was 32% (165 of 514). There were no differences between regimens in response rates (arm A, 28% 47 of 140; arm B, 34% 60 of 174; and arm C, 34% 58 of 170) or in survival. There have been nine possible chemotherapy-related fatalities. Grade III to IV toxic effects did not differ appreciably by arm and included stomatitis (12% to 14%), diarrhea (15% to 19%), nausea (7% to 9%), and vomiting (6% to 8%).
There was no difference in response, survival, or toxicity between these three different leucovorin formulations combined with 5-FU.
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