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Dicamba-resistant (DR) kochia is an increasing concern for growers in the US Great Plains, including Kansas. Greenhouse and field experiments (Garden City and Tribune, KS, in the 2014 to 2015 growing season) were conducted to characterize the dicamba resistance levels in two recently evolved DR kochia accessions collected from fallow fields (wheat–sorghum–fallow rotation) near Hays, KS, and to determine the effectiveness of various PRE herbicide tank mixtures applied in fall or spring prior to the fallow year. Dicamba dose–response studies indicated that the KS-110 and KS-113 accessions had 5- to 8-fold resistance to dicamba, respectively, relative to a dicamba-susceptible (DS) accession. In separate field studies, atrazine-based PRE herbicide tank mixtures, dicamba + pendimethalin + sulfentrazone, and metribuzin + sulfentrazone when applied in the spring had excellent kochia control (85% to 95%) for 3 to 4 mo at the Garden City and Tribune sites. In contrast, kochia control with those PRE herbicide tank mixtures when applied in the fall did not exceed 79% at the later evaluation dates. In conclusion, the tested kochia accessions from western Kansas had evolved moderate to high levels of resistance to dicamba. Growers should utilize these effective PRE herbicide tank mixtures (multiple sites of action) in early spring to manage kochia seed bank during the summer fallow phase of this 3-yr crop rotation (wheat–corn/sorghum–fallow) in the Central Great Plains.
Evolution and rapid spread of herbicide-resistant (HR) kochia has become a significant challenge for growers in the U.S. Great Plains. The main objectives of this research were to confirm and characterize the response of putative auxinic HR (Aux-HR) kochia accessions (designated as KS-4A, KS-4D, KS-4H, KS-10A, KS-10-G, and KS-10H) collected from two different corn fields near Garden City, KS, to dicamba and fluroxypyr and to determine the EPSPS gene copy number to detect whether those accessions were also resistant to glyphosate. Single-dose experiments indicated that putative Aux-HR kochia accessions had 78% to 100% and 85% to 100% survivors when treated with dicamba (560 g ae ha−1) and fluroxypyr (235 g ae ha−1), respectively. Whole-plant dicamba dose–response studies revealed that the selected Aux-HR accessions had 2.9- to 15.1- and 3.1- to 9.4-fold resistance to dicamba relative to two susceptible accessions (MT-SUS and KS-SUS). In a separate fluroxypyr dose–response experiment, the selected Aux-HR accessions also exhibited 3.8- to 7.3- and 3.0- to 8.6-fold resistance to fluroxypyr on the basis of shoot fresh and dry weight responses, respectively. The confirmed Aux-HR kochia accessions also had 3 to 13 EPSPS gene copies relative to MT-SUS and KS-SUS accessions (each with 1 EPSPS gene copy). These results suggest that the putative Aux-HR kochia accessions from Kansas had developed moderate to high levels of cross-resistance to dicamba and fluroxypyr and low to high levels of resistance to glyphosate. This is the first confirmation of kochia accessions with cross-resistance to dicamba and fluroxypyr in Kansas. Growers should use diverse kochia control programs, including the proper use of dicamba and fluroxypyr stewardship, use of cover crops, occasional tillage, diversified crop rotations, and alternative effective herbicides to prevent further evolution and spread of Aux-HR kochia on their fields.
Kochia [Bassia scoparia (L.) A. J. Scott] is one of the most troublesome weeds throughout the North American Great Plains. Herbicides such as glyphosate and dicamba have been used widely to control B. scoparia for decades. However, many B. scoparia populations have evolved resistance to these herbicides due to selection. Especially, dicamba-resistant B. scoparia populations are often also found to be glyphosate-resistant. The objective of this research was to determine whether these two herbicide resistances are linked in B. scoparia. Reciprocal crosses were performed between glyphosate- and dicamba-resistant (GDR) and glyphosate- and dicamba-susceptible (GDS) B. scoparia to produce F1 and F2 progeny. Two F1 and seven F2 progeny families were screened with various doses of dicamba or glyphosate. All the F1 progeny survived both dicamba and glyphosate treatments. Chi-square analyses of F2 progeny suggest (1) glyphosate and dicamba resistances in B. scoparia are inherited via single, dominant nuclear genes; and (2) glyphosate- and dicamba-resistant genes are not linked. Thus, the dicamba and glyphosate resistances appear to have evolved independently due to intense selection but do not seem to spread together.
Angiostrongylus cantonensis (rat lungworm), a parasitic nematode, is expanding its distribution. Human infection, known as angiostrongyliasis, may manifest as eosinophilic meningitis, an emerging infectious disease. The range and incidence of this disease are expanding throughout the tropics and subtropics. Recently, the Hawaiian Islands have experienced an increase in reported cases. This study addresses factors affecting the parasite's distribution and projects its potential future distribution, using Hawaii as a model for its global expansion. Specimens of 37 snail species from the Hawaiian Islands were screened for the parasite using PCR. It was present on five of the six largest islands. The data were used to generate habitat suitability models for A. cantonensis, based on temperature and precipitation, to predict its potential further spread within the archipelago. The best current climate model predicted suitable habitat on all islands, with greater suitability in regions with higher precipitation and temperatures. Projections under climate change (to 2100) indicated increased suitability in regions with estimated increased precipitation and temperatures, suitable habitat occurring increasingly at higher elevations. Analogously, climate change could facilitate the spread of A. cantonensis from its current tropical/subtropical range into more temperate regions of the world, as is beginning to be seen in the continental USA.
The Neotoma Paleoecology Database is a community-curated data resource that supports interdisciplinary global change research by enabling broad-scale studies of taxon and community diversity, distributions, and dynamics during the large environmental changes of the past. By consolidating many kinds of data into a common repository, Neotoma lowers costs of paleodata management, makes paleoecological data openly available, and offers a high-quality, curated resource. Neotoma’s distributed scientific governance model is flexible and scalable, with many open pathways for participation by new members, data contributors, stewards, and research communities. The Neotoma data model supports, or can be extended to support, any kind of paleoecological or paleoenvironmental data from sedimentary archives. Data additions to Neotoma are growing and now include >3.8 million observations, >17,000 datasets, and >9200 sites. Dataset types currently include fossil pollen, vertebrates, diatoms, ostracodes, macroinvertebrates, plant macrofossils, insects, testate amoebae, geochronological data, and the recently added organic biomarkers, stable isotopes, and specimen-level data. Multiple avenues exist to obtain Neotoma data, including the Explorer map-based interface, an application programming interface, the neotoma R package, and digital object identifiers. As the volume and variety of scientific data grow, community-curated data resources such as Neotoma have become foundational infrastructure for big data science.
Timing of weed emergence and seed persistence in the soil influence the ability to implement timely and effective control practices. Emergence patterns and seed persistence of kochia populations were monitored in 2010 and 2011 at sites in Kansas, Colorado, Wyoming, Nebraska, and South Dakota. Weekly observations of emergence were initiated in March and continued until no new emergence occurred. Seed was harvested from each site, placed into 100-seed mesh packets, and buried at depths of 0, 2.5, and 10 cm in fall of 2010 and 2011. Packets were exhumed at 6-mo intervals over 2 yr. Viability of exhumed seeds was evaluated. Nonlinear mixed-effects Weibull models were fit to cumulative emergence (%) across growing degree days (GDD) and to viable seed (%) across burial time to describe their fixed and random effects across site-years. Final emergence densities varied among site-years and ranged from as few as 4 to almost 380,000 seedlings m−2. Across 11 site-years in Kansas, cumulative GDD needed for 10% emergence were 168, while across 6 site-years in Wyoming and Nebraska, only 90 GDD were needed; on the calendar, this date shifted from early to late March. The majority (>95%) of kochia seed did not persist for more than 2 yr. Remaining seed viability was generally >80% when seeds were exhumed within 6 mo after burial in March, and declined to <5% by October of the first year after burial. Burial did not appear to increase or decrease seed viability over time but placed seed in a position from which seedling emergence would not be possible. High seedling emergence that occurs very early in the spring emphasizes the need for fall or early spring PRE weed control such as tillage, herbicides, and cover crops, while continued emergence into midsummer emphasizes the need for extended periods of kochia management.
Programmed Cell Death – 1 (PD1) inhibition activates tumor-specific T-lymphocytes and is an effective clinical therapy against some cancers. Preclinical data regarding immune checkpoint inhibitors against malignant glioma is scant, and interim analyses of clinical trials suggest modest effect in patients as single agents. We examined PD-1 inhibition in murine glioblastoma models in combination with other immunomodulatory agents. Methods – Syngeneic glioma tumors (GL261 and CT2A) were implanted intracranially in C57/Bl6 mice. In separate experiments, PD-1 inhibition was combined with antibody blockade of t-cell immunoglobulin and mucin protein (TIM3), ligation of OX40 on T-lymphocytes, or vaccination with irradiated GM-CSF expressing tumor cells. Systemic antitumor immunity and tumor infiltrating lymphocytes were analyzed by ELISPOT assay and flow cytometry, respectively. Results - In both syngeneic glioma models, day 3,6, and 9 systemic delivery of a monoclonal antibody against PD-1 led to increased survival vs. controls. In animals with GL261 intracranial tumors, survival was improved by combination of PD-1 blockade with subcutaneous injection of irradiated GM-CSF expressing GL261 tumor cells, with antibody blockade of t-cell immunoglobulin and mucin protein 3 (TIM3), or binding of OX40 on T-lymphocytes by an activating antibody. In most cases, ELISPOT analyses demonstrated enhanced Th1 immunity by combination immunotherapies. Vaccination was associated with an increased intratumoral CD8+ T lymphocyte / FoxP3+ T lymphocyte ratio. Conclusion –Blockade of PD-1 on T lymphocytes in glioma-bearing mice is active. Both antitumor immunity and survival can be enhanced by combination of PD-1 inhibition with agents that activate antitumor immunity by complementary mechanisms.
During the past three years radiocarbon assay has emerged as a primary tool in the quantitative assignment of sources of urban and rural particulate pollution. Its use in several major field studies has come about because of its excellent (fossil/biogenic) discriminating power, because of advances in 14C measurements of small samples, and because of the increased significance of carbonaceous particles in the atmosphere. The problem is especially important in the cities, where increased concentrations of fine particles lead to pollution episodes characterized by poor visibility and changes in the radiation balance (absorption, scattering), and immediate and possibly long-term health effects. Efforts in source apportionment in such affected areas have been based on emissions inventories, dispersion modeling, and receptor modeling – ie, chemical and physical (and statistical) characterization of particles collected at designated receptor sites. It is in the last category that 14C has become quite effective in helping to resolve particle sources. Results are presented for studies carried out in Los Angeles, Denver, and Houston which incorporated 14C measurements, inorganic and organic chemical characterization, and receptor modeling. The 14C data indicated wide ranging contributions of biogenic and fossil carbon sources – eg, <10% to 60% contemporary (biogenic) in Houston – depending on meteorological, biological, and anthropological activity. The combined (chemical, isotopic, statistical) data point to sources such as vehicles, wood combustion, power plants, and vegetation.
When 14C signals approach background levels, the validity of assumptions concerning Poisson counting statistics and measurement system stability becomes crucial in interpreting the resultant low-level counting observations. This has been demonstrated in our previous work on detection limits for non-Poisson error and it is critical in our current studies of carbonaceous pollutants, where the 14C signal from just 5 mg C is comparable to that of the background for our miniature gas proportional counters. To assure data quality, our multi-detector system is designed for the on-line monitoring of critical parameters that reflect both the (statistical) nature of the non-Poisson errors and the underlying (physical) causes. It sends >60 bits of information/pulse to a microprocessor which automatically generates, for each counting period, two-dimensional spectra and multiparameter correlation and control charts. To evaluate the validity of long-term counting of 1–10 mg C we use robust (statistical) estimators, optimal counting interval subdivision, and time series analysis of the individual pulses. New opportunities for selective sampling and chemical fractionation which come with the small sample measurement capability have led us to give special attention also to higher control levels, involving e g, isotonic heterogeneity and representative standard materials.
It has been shown that contamination from humic acids, chitin, fungal products, etc., contributing young carbon, and from bitumen and carbonate, contributing old carbon, may not be completely removed from wood and char samples by the usual hydrochloric acid and sodium hydroxide pretreatments of the samples. A procedure is offered for the isolation of a pure chemical substance from such samples, cellulose from wood and uncombined carbon from char, that must represent the original material. Cellulose is prepared by boiling the resin-free sample in 1.25% H2SO4 and 1.25% NaOH, adding Schweitzer's reagent, filtering, and precipitating from the filtrate by acidification. Uncombined carbon is separated from char samples as the flocculant precipitate remaining after boiling in 70% HNO3, followed by settling overnight from a large volume of 6M HNO3. A simple procedure for the chemical examination of char samples is also offered for the estimation of the amounts of bitumen, carbonate, combined, and uncombined carbon in char.
An example of how man's contaminants are introduced, deposited, and retained in sediments giving a chronological record of events has been developed for Lake Washington, Seattle. Significant amounts of both inorganic and organic compounds in the environment originate from fossil fuel sources, such as power plants and motor vehicles. Many organic compounds are introduced also from contemporary biogenic materials. Through the combined carbon isotope analysis technique (CCIA), we can distinguish between fossil and contemporary carbon sources classes (using 14C), as well as sources within each class (using 13C). To establish the chronology of the organic carbon pollutant input to the lake sediment, the ages of the layers were determined using 210pb dating techniques. Sediment profiles of trace metals and a fallout radionuclide plutonium were also obtained and compared with the carbon isotope profiles. The results show that the total organic carbon (TOC) concentration correspond to 93% modern carbon before 1905. This 14C concentration in TOC decreased to ∼60% modern in the 1930's and now is between 95 and 80% modern. The lipid fraction is ca 30% modern and the total aromatic hydrocarbon fraction reached a minimum of 5% modern in 1954. The large decrease in 14C of TOC around 1930 is believed to be due to coal dust or fly ash. The trace metal concentration also increased substantially at this time. The pattern observed in the sediment thus reflects the change in the local energy consumption pattern from a predominately coal to an oil-based economy. From the plutonium profile we infer that mixing occurs for 3 or 4 years before the sediment layers are compacted.
The abrupt millennial-scale changes associated with the Younger Dryas (YD) event (“chronozone”) near the dawn of the Holocene are at least hemispheric, if not global, in extent. Evidence for the YD cold excursion is abundant in Europe but fairly meager in central North America. We are engaged in an investigation of high-resolution environmental changes in mid-North America over several millennia (about 10,000 to 14,000 BP) during the Late Glacial–Early Holocene transition, including the YD interval. Several sites containing logs or stumps have been identified and we are in the process of initial sampling or re-sampling them for this project. Here, we report on a site in central Illinois containing a deposit of logs initially thought to be of YD age preserved in alluvial sands. The assemblage of wood represents hardwood (angiosperm) trees, and the ring-width characteristics are favorable to developing formal tree-ring chronologies. However, 4 new radiocarbon dates indicate deposition of wood may have taken place over at least 8000 14C yr (6000–14,000 BP). This complicates the effort to develop a single floating chronology of several hundred years at this site, but it may provide wood from a restricted region over a long period of time from which to develop a sequence of floating chronologies, the timing of deposition and preservation of which could be related to paleoclimatic events and conditions.
The occurrence, quantification, and distribution patterns of deformed wing virus (DWV) and sacbrood virus (SBV), (family Iflaviridae); black queen cell virus (BQCV), Israeli acute paralysis virus (IAPV), Kashmir bee virus (KBV), and acute bee paralysis virus (ABPV) (family Dicistroviridae), and chronic bee paralysis virus (CBPV) (unclassified), were characterised in 80 “healthy” honey bee (Apis mellifera Linnaeus; Hymenoptera: Apidae) colonies and 23 “unhealthy” colonies by employing reverse transcription polymerase chain reaction (RT-PCR) for virus identification and quantitative real-time polymerase chain reaction (qPCR) for quantification. All seven viruses were common but the most prevalent viruses were DWV, followed by BQCV and IAPV. For most viruses, prevalence in surviving but unhealthy colonies in spring did not differ from that of healthy baseline colony levels in fall suggesting spring prevalence level would not be a useful metric for diagnosis of factors contributing to colony loss. Sacbrood virus was the only virus that was more prevalent in unhealthy colonies from Manitoba, Canada than in healthy from colonies across Canada but did not differ from healthy colonies within Manitoba. Multiple infections were ubiquitous with a few colonies having simultaneous infection with as many as five viruses. Among the three viruses quantified by qPCR, DWV had the highest relative concentrations in pooled samples of worker bees. Deformed wing virus was the only virus within healthy colonies that differed in fall concentration among provinces and was at high levels in unhealthy colonies. Black queen cell virus was positively correlated with IAPV across all samples. Our study provides the first major baseline study of viruses in Canadian honey bees.
During the last deglaciation temperatures over midcontinental North America warmed dramatically through the Bølling-Allerød, underwent a cool period associated with the Younger-Dryas and then reverted to warmer, near modern temperatures during the early Holocene. However, paleo proxy records of the hydroclimate of this period have presented divergent evidence. We reconstruct summer relative humidity (RH) across the last deglacial period using a mechanistic model of cellulose and leaf water δ18O and δD combined with a pollen-based temperature proxy to interpret stable isotopes of sub-fossil wood. Midcontinental RH was similar to modern conditions during the Last Glacial Maximum, progressively increased during the Bølling-Allerød, peaked during the Younger-Dryas, and declined sharply during the early Holocene. This RH record suggests deglacial summers were cooler and characterized by greater advection of moisture-laden air-masses from the Gulf of Mexico and subsequent entrainment over the mid-continent by a high-pressure system over the Laurentide ice sheet. These patterns help explain the formation of dark-colored cumulic horizons in many Great Plains paleosol sequences and the development of no-analog vegetation types common to the Midwest during the last deglacial period. Likewise, reduced early Holocene RH and precipitation correspond with a diminished glacial high-pressure system during the latter stages of ice-sheet collapse.
Field experiments were conducted in grain sorghum at five locations in Kansas in 2009 and 2010, to evaluate the efficacy and crop safety of early- to mid-POST (EMPOST) and late-POST (LPOST) applications of premixed pyrasulfotole and bromoxynil (PYRA&BROM) in tank mix combinations with atrazine or atrazine plus 2,4-D ester or dicamba compared to bromoxynil plus atrazine. PYRA&BROM at 244 or 300 g ai ha−1 plus atrazine at 560 g ai ha−1 applied EMPOST controlled pigweed species (Palmer amaranth, tumble pigweed, and redroot pigweed), kochia, velvetleaf, common sunflower, ivyleaf morningglory, and common lambsquarters 93% or greater. Puncturevine control among three locations ranged from 85 to 99%. Control of most weed species was not improved by increasing PYRA&BROM rate from 244 to 300 g ha−1 or by tank mixing 2,4-D or dicamba with PYRA&BROM plus atrazine. However, ivyleaf morningglory control was improved at the LPOST timing by adding 2,4-D or dicamba at 140 g ae ha−1. In no instance did any PYRA&BROM treatment provide greater weed control than bromoxynil plus atrazine at 281 + 560 g ha−1 when applied EMPOST, but in most instances PYRA&BROM treatments were more effective than bromoxynil plus atrazine when applied LPOST. Generally, PYRA&BROM treatments were more effective when applied EMPOST than LPOST, especially when 2,4-D or dicamba was added. PYRA&BROM plus atrazine treatments caused foliar bleaching in sorghum within 7 ± 3 d after treatment, but recovery was complete within 3 to 4 wk and grain yields were not reduced. Tank mixing dicamba with PYRA&BROM and atrazine occasionally reduced visible crop response compared to PYRA&BROM plus atrazine. Our results indicate that PYRA&BROM plus atrazine with or without 2,4-D or dicamba selectively controls several troublesome broadleaf weeds in grain sorghum. Foliar bleaching of sorghum leaves can occur but the symptoms are transient, and grain yields are not likely to be reduced.
Kochia is a troublesome weed throughout the western United States. Although glyphosate effectively controls kochia, poor control was observed in several no-till fields in Kansas. The objectives of this research were to evaluate kochia populations response to glyphosate and examine the mechanism that causes differential response to glyphosate. Glyphosate was applied at 0, 54, 109, 218, 435, 870, 1305, 1740, 3480, and 5220 g ae ha−1 on 10 kochia populations. In general, kochia populations differed in their response to glyphosate. At 21 d after treatment, injury from glyphosate applied at 870 g ha−1 range from 4 to 91%. In addition, glyphosate rate required to cause 50% visible injury (GR50) ranged from 470 to 2149 g ha−1. Differences in glyphosate absorption and translocation and kochia mineral content were not sufficient to explain differential kochia response to glyphosate.
Background: Connecting willing patients with dementia to suitable clinical research studies has been historically challenging. The United Kingdom Dementia and Neurodegenerative Research Network (DeNDRoN) was established to link patients into high-quality studies. One component is DemReg, a register of dementia patients and their carers who have agreed to be approached regarding future research studies. The limited literature highlights the predominance of altruism mediating research register participation. The objective of this study was to understand the motivations of patients and carers to participate in DemReg.
Methods: There were 107 participants in the study, interviewed using a questionnaire to determine which factors were important in their decision to be on the register. The study compared the proportion of the altruistic motivations articulated with the proportion of the other answers offered.
Results: The two most important motivators for registering on DemReg were to help others (44%; p < 0.001) or themselves (29%; p < 0.001) and altruistic motives took precedence over those for personal benefit. Participants were not motivated by the prospect of payment or by concern that they would be letting down their clinician if they did not register.
Conclusions: There are currently major projects within the United Kingdom to increase the number of patients on dementia registers and to further involvement in dementia research. This study, to the best of our knowledge, is the first to assess the motivations of patients and carers for joining a dementia research register in the United Kingdom, and the findings highlight the importance of altruistic motives.
The paper reviews the recent history and present state of knowledge of the flora and its geographical relationships. Key environmental factors are identified and the range of habitats is discussed, with some comment on plant communities. Recent accounts of island flora and plant communities are available for Skye, Rhum and Mull in contrast to the Outer Hebrides where none are available for the main islands. There is no checklist for the flora of the Inner Hebrides, since the islands are best described individually, not as a group.
The geography of the flora and plant communities is discussed and related to that of the Outer Hebrides and the Scottish mainland. Inter-island relationships are described and related to habitat differences. Compared with the Outer Hebrides, machair and extensive wetland habitats are lacking through much of the Inner Hebrides, but there is a much greater extent of upland and mountain environment. There is much more woodland in the Inner Hebrides but the woodland development does not attain the levels of the adjacent mainland.
Despite the greater extent of upland and mountain environments in the Inner than in the Outer Hebrides, many of the plant communities of central Scotland are absent while those of western character are well represented.
British investors, whose support was of importance to American railroad development, fluctuated between enthusiasm and dismay. Low investment per mile, the performance of certain blue chip carriers, and the native growth potential all stimulated the vital flow of foreign capital. Rate wars, overcapitalization, stock price fluctuations, imprudent reorganizations, and low business morality had an inhibiting effect. In most cases American investments offered little opportunity to exert control. By the late 1890's, British investors had largely outgrown their enchantment with the American railroad bonanza.