Modeling the evolution of herbicide resistance in weed species with a complex life cycle.

A growing number of weed species have evolved resistance to herbicides in recent years, which causes an immense financial burden to farmers. An increasingly popular method of weed control is the adoption of crops that are resistant to specific herbicides, which allows farmers to apply the herbicide during the growing season without harming the crop. If such crops are planted in the presence of closely related weed species, it is possible that resistance genes could transfer from the crop species to feral populations of the wild species via gene flow and become stably introgressed under ongoing selective pressure by the herbicide. We use a density-dependent matrix model to evaluate the effect of planting such crops on the evolution of herbicide resistance under a range of management scenarios. Our model expands on previous simulation studies by considering weed species with a more complex life cycle (perennial, rhizomatous weed species), studying the effect of environmental variation in herbicide effectiveness, and evaluating the role of common simplifying genetic assumptions on resistance evolution. Our model predictions are qualitatively similar to previous modeling studies using species with a simpler life cycle, which is, crop rotation in combination with rotation of herbicide site of action effectively controls weed populations and slows the evolution of herbicide resistance. We find that ignoring the effect of environmental variation can lead to an over- or under-prediction of the speed of resistance evolution. The effect of environmental variation in herbicide effectiveness depends on the resistance allele frequency in the weed population at the beginning of the simulation. Finally, we find that degree of dominance and ploidy level have a much larger effect on the predicted speed of resistance evolution compared to the rate of gene flow.

A Study of GP Workload and Satisfaction.

Aims In this novel study in the Irish setting, we quantified the number items managed per General Practitioner (GP) consult, how each item is managed, and impact on a GP's job satisfaction. Methods Participating GPs at two surgeries completed a questionnaire - integrated into the practice management software - after each consultation that satisfied the inclusion criteria during a four-week period. Results Due to feasibility constraints, 500 of 857 (58.3%) completed questionnaires were randomly selected for our sample. GPs manage an average of 1.76 items per consultation. Older patients presented with more items. Greater number of presenting items led to less being managed on the day 71% (n=5) for 5 items vs. 95.2% (n= 246) for 1 item, longer consultation duration (mean = 14.63 minutes (4-45) and decreased GP satisfaction, mean 8/10 (2-10). Conclusion Increasing the number of items in a GP consultation has a statistically significant effect on duration of consultation, how each item is managed, and even GP satisfaction.

Do the contemporary dietary patterns of children align with national food and nutrient recommendations?

BACKGROUND: Childhood nutrition is important in optimising growth, development and future health. The present study compared dietary intakes of Australian children aged 4-8 years with (i) Australian Guide to Healthy Eating (AGHE) food group recommendations and (ii) age-specific Nutrient Reference Values (NRVs), in addition to (iii) describing food group intakes of children meeting key NRVs. METHODS: Data were obtained from a representative sample of children (n = 789) from the National Nutrition and Physical Activity Survey between May 2011 and June 2012. Parent-reported 24-h recall dietary data were disaggregated into five core food groups, along with energy-dense, nutrient-poor (EDNP) foods, with intakes being compared with AGHE recommendations. Food group intakes were compared for children meeting the NRVs for 10 nutrients used for the development of AGHE food groups. Chi-squared and t-tests were performed to determine differences in food group intakes with P < 0.05 considered statistically significant. RESULTS: Only one child met the recommended daily servings for all AGHE core food groups and none met both core and energy-dense, nutrient-poor (EDNP) food group recommendations. The lowest level of alignment (percentage meeting recommendations) was for vegetables (4.6%) and the highest was for fruit (47.7%). Mean (SD) daily intake of EDNP foods [4.7 (3.2) serves day-1 ] accounted for 38.4% of total energy intakes. Children meeting key NRVs (n = 395) consumed greater daily servings of fruit [2.2 (1.7)], dairy [2.2 (1.2)] and EDNP foods [5.0 (3.4)] compared to the total sample (n = 789). CONCLUSIONS: Significant discrepancies exist between contemporary dietary patterns of Australian children and national recommendations. Future AGHE revisions should incorporate greater diversity of consumption patterns, including sub-categories of EDNP foods.

Loss of PIM2 enhances the anti-proliferative effect of the pan-PIM kinase inhibitor AZD1208 in non-Hodgkin lymphomas.

BACKGROUND: A promising therapeutic approach for aggressive B-cell Non-Hodgkin lymphoma (NHL), including diffuse large B-cell lymphoma (DLBCL), and Burkitt lymphoma (BL) is to target kinases involved in signal transduction and gene regulation. PIM1/2 serine/threonine kinases are highly expressed in activated B-cell-like DLBCL (ABC-DLBCL) with poor prognosis. In addition, both PIM kinases have a reported synergistic effect with c-MYC in mediating tumour development in several cancers, c-MYC gene being translocated to one of the immunoglobulin loci in nearly all BLs. METHODS: For these reasons, we tested the efficiency of several PIM kinase inhibitors (AZD1208, SMI4a, PIM1/2 inhibitor VI and Quercetagetin) in preventing proliferation of aggressive NHL-derived cell lines and compared their efficiency with PIM1 and/or PIM2 knockdown. RESULTS: We observed that most of the anti-proliferative potential of these inhibitors in NHL was due to an off-target effect. Interestingly, we present evidence of a kinase-independent function of PIM2 in regulating cell cycle. Moreover, combining AZD1208 treatment and PIM2 knockdown additively repressed cell proliferation. CONCLUSION: Taken together, this study suggests that at least a part of PIM1/2 oncogenic potential could be independent of their kinase activity, justifying the limited anti-tumorigenic outcome of PIM-kinase inhibitors in NHL.

Florfenicol pharmacokinetics in healthy adult alpacas after subcutaneous and intramuscular injection.

A single dose of florfenicol (Nuflor(®)) was administered to eight healthy adult alpacas at 20 mg/kg intramuscular (i.m.) and 40 mg/kg subcutaneous (s.c.) using a randomized, cross-over design, and 28-day washout period. Subsequently, 40 mg/kg florfenicol was injected s.c. every other day for 10 doses to evaluate long-term effects. Maximum plasma florfenicol concentrations (C(max), measured via high-performance liquid chromatography) were achieved rapidly, leading to a higher C(max) of 4.31±3.03 µg/mL following administration of 20 mg/kg i.m. than 40 mg/kg s.c. (C(max): 1.95±0.94 µg/mL). Multiple s.c. dosing at 48 h intervals achieved a C(max) of 4.48±1.28 µg/mL at steady state. The area under the curve and terminal elimination half-lives were 51.83±11.72 µg/mL·h and 17.59±11.69 h after single 2 mg/kg i.m. dose, as well as 99.78±23.58 µg/mL·h and 99.67±59.89 h following 40 mg/kg injection of florfenicol s.c., respectively. Florfenicol decreased the following hematological parameters after repeated administration between weeks 0 and 3: total protein (6.38 vs. 5.61 g/dL, P<0.0001), globulin (2.76 vs. 2.16 g/dL, P<0.0003), albumin (3.61 vs. 3.48 g/dL, P=0.0038), white blood cell count (11.89 vs. 9.66×10(3)/µL, P<0.044), and hematocrit (27.25 vs. 24.88%, P<0.0349). Significant clinical illness was observed in one alpaca. The lowest effective dose of florfenicol should thus be used in alpacas and limited to treatment of highly susceptible pathogens.

Rapid creation of a website to produce educational and clinical support resources for global use during and beyond the COVID-19 pandemic.

It became clear at the onset of the pandemic that radiography could play an important role in diagnosing and staging COVID-19. The key modality would be mobile chest radiography. However, at the onset of the pandemic, no literature existed to indicate whether or not chest X-ray imaging could be used effectively to diagnose or exclude COVID-19. This article explains how a website was created, at speed, during the initial phase of the COVID-19 pandemic. Containing holistic information, the website helped enable rapid redeployment of radiographers onto the frontline where chest X-ray imaging was needed. It aimed to help train radiographers take (and interpret) chest radiographs in high-risk areas that contained large numbers of COVID-19 patients. Within one year, the website had been used in 157 countries. This article documents the approach taken to create the website and suggestions are made about how, in the future, a rapid approach could be achieved to create other websites - should an international crisis occur again. This paper also outlines how stakeholders and content authors from across the world were brought together and supported to create the website. It goes on to explain the leadership style that was adopted to create the website and why that style was selected. An explanation is offered about the project management approach and how its ingredients relate to a published model. Aside from simply providing a historical account of how the website was created, we hope the narrative offers food for thought on how to respond rapidly during an international crisis to formulate and implement a unified international-level solution which addresses an urgent need.

Beyond A single stimulus: How to leverage the federal government to advance clean energy innovation?

There is a critical need to accelerate and improve the innovation process for clean energy technologies. In order to stem the most-dire effects of the climate crisis, there will need to be increased research, development, demonstration, commercialization, deployment, and adoption of clean energy technologies. The innovation process for energy technologies is especially challenging compared with other technological sectors, and can be strengthened through better use of the unique capabilities of the federal government. Recently, the focus of efforts to enhance clean energy innovation has been on what a stimulus bill and/or single piece of legislation can achieve. However, the federal government possesses numerous other means for strengthening the energy innovation process: (1) taking on a greater quantity of risk in the federal government's RD&D portfolio; (2) extending the federal government's support for clean energy technologies through its purchasing power; (3) drawing on the full scope of the federal government; and (4) putting energy innovation in the context of societal transformations. Insights on how to draw on the federal government's resources to support clean energy innovation through these means are described and discussed with an eye toward applicability and actionable steps.

Benefits and Risks of Intercropping for Crop Resilience and Pest Management.

To combat climate change, farmers must innovate through ecological intensification to boost food production, increase resilience to weather extremes, and shrink the carbon footprint of agriculture. Intercropping (where alternative crops or noncrop plants are integrated with cash crops) can strengthen and stabilize agroecosystems under climate change by improving resource use efficiency, enhancing soil water holding capacity, and increasing the diversity and quality of habitat for beneficial insects that provide pollination services and natural pest control. Despite these benefits, intercropping has yet to be widely adopted due to perceived risks and challenges including decreased crop yield, increased management complexity, a steep learning curve for successful management, and increased susceptibility to pests. Here, we explore the major benefits of intercropping in agricultural systems for pest control and climate resilience reported in 24 meta-analyses, while addressing risks and barriers to implementation. Most studies demonstrate clear benefits of intercropping for weed, pathogen, insect pest control, relative yield, and gross profitability. However, relatively few studies document ecosystem services conferred by intercrops alongside labor costs, which are key to economic sustainability for farmers. In addition to clearer demonstrations of the economic viability of intercropping, farmers also need strong technical and financial support during the adoption process to help them troubleshoot the site-specific complexities and challenges of managing polycultures. Ecological intensification of agriculture requires a more strategic approach than simplified production systems and is not without risks and challenges. Calibrating incentive programs to reduce financial burdens of risk for farmers could promote more widespread adoption of intercropping.

On the role of the response of the cell membrane in determining virus virulence. Contrasting effects of the parainfluenza virus SV5 in two cell types.

The simian myxovirus SV5 multiplies in a continuous line of baby hamster kidney (BHK21-F) cells causing extensive cell fusion, followed by cell death. After inoculation of 15 PFU/cell, the latent period was 7 hr, the doubling time approximately 60 min, and the yield 7 PFU per cell. Giant cell formation began about 6 hr after infection and rapidly progressed to the formation by 14 to 18 hr of a single syncytium which disintegrated by 24 to 36 hr. In contrast, SV5 multiplies in primary rhesus monkey kidney cells for long periods of time producing high yields of virus with little cytopathic effect. High multiplicities of SV5 induced cell fusion in BHK21-F cells within 1 hr in the absence of virus multiplication but had no visible effect on monkey kidney cells. Time-lapse photomicrography has demonstrated that giant cells form by fusion of infected cells, and that some polykaryocytes divide. During aberrant division of polykaryocytes giant nuclei are formed from the nuclear material of several parent nuclei. The cytoplasmic development of viral antigens as demonstrated by immunofluorescence is similar in BHK21-F and monkey kidney cells. Synthesis of cellular DNA, RNA, and protein in monkey kidney cells is not shut off by SV5-infection, and in BHK21-F cells synthesis of these macromolecules is not inhibited until after extensive cell fusion has occurred 12 to 15 hr after infection. Persistently infected BHK21-F and monkey kidney cells have been serially carried through 11 and 28 cell passages, respectively. The results suggest that whether SV5 acts as a moderate virus, as in monkey kidney cells, or a virulent virus, as in BHK21-F cells, depends on the response of the cell membrane to the virus.

The serological classification of Neisseria gonorrhoeae. I. Isolation of the outer membrane complex responsible for serotypic specificity.

Neisseria gonorrhoeae has been subdivided into several classes of serological distinct groups. The serotyping system is based upon the antigenic specificity of a protein serotype antigen. This protein is the major polypeptide of the outer membrane of the gonococcus and accounts for over 60% of that membrane's total protein. The serotype antigen complex was isolated by mild extraction of intact organisms in 200 mM lithium acetate buffer, pH 6.0 with 10 mM EDTA for 2 h at 45 degrees C. The extract was fractionated on Sepharose 6B and partially purified by precipitation at pH 4.2 by addition of 10% (vol/vol) acetic acid. Each serotype antigen has a unique subunit molecular size as determined by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE). Preliminary typing of a gonococcal strain may be performed by comparative SDA-PAGE. To date, 16 different serotypes, representing a diverse distribution, have been isolated.

Murine hematopoietic cells with pre-B or pre-B/myeloid characteristics are generated by in vitro transformation with retroviruses containing fes, ras, abl, and src oncogenes.

In vitro infection of bone marrow or fetal liver cells with retroviruses containing fes, abl, ras, or src oncogenes resulted in the transformation of early B lineage cells. All cell lines tested possessed rearrangements at the Ig heavy chain locus and some had rearrangements at the K chain locus. The majority of the lines corresponded phenotypically to Lyb-2+, Ly-5(B220)+, ThB- large pre-B cells, although some were classified as pro-B cells because of their Lyb-2+, Ly-17+, Ly-5(B220)- phenotype. We identified two cell lines that contained subpopulations of cells that coexpressed the B lineage antigens Lyb-2 and Ly-5(B220) and the myeloid lineage antigen Mac-1. Single-cell FMF cloning of these subpopulations showed that Mac-1+ cells were derived from Mac-1- cells and that these Mac-1+-cloned cells further differentiated into cells with phenotypic and functional characteristics of mature macrophages.

Cell surface immunoglobulin. VII. Synthesis, shedding, and secretion of immunoglobulin by lymphoid cells of germ-free mice.

Lymphoid cells from the spleen, lymph nodes, and thoracic duct of axenic and control mice were incubated with [(3)H]tyrosine and synthesis and secretion of protein and Ig studied. It was found that only IgM was synthesized by cells from axenic mice whereas cells from control mice also synthesized IgG. Splenocytes from both axenic and control mice had 8S IgM on their surface. Radiolabeled splenocytes from axenic mice were incubated to determine the kinetics of release of (125)I-labeled cell surface IgM and [(3)H]tyrosine-labeled IgM. Cell surface IgM was shed as 8S with an initial half-life of release of 5-8 h whereas [(3)H]tyrosine-labeled Ig was secreted as 19S with an initial half-life of 2-3 h. These findings suggest that two independent pathways are involved. It is suggested that small lymphocytes shed 8S IgM and plasma cells secrete 19S IgM. It was observed that lymphoid cells from axenic mice synthesize a higher proportion of IgM relative to total protein. Electron microscopic examination of splenocytes from such mice revealed a markedly higher proportion of plasma cells and a paucity of lymphoblasts compared to controls. It was suggested, therefore, that axenic mice lack a population of stimulated T cells which can induce a switch from IgM to IgG synthesis and which is capable of suppressing IgM synthesis. Lymphoid cells from axenic mice synthesize and secrete less protein that coprecipitates with antigen-antibody complexes.

Expression of the 6C3 antigen on murine hematopoietic neoplasms. Association with expression of abl, ras, fes, src, erbB, and Cas NS-1 oncogenes but not with myc.

The monoclonal antibody 6C3 was used to test a wide variety of murine hematopoietic neoplasms for cell surface expression of a 160 kD glycoprotein (gp160(6C3)) previously shown to be expressed by neoplastic pre-B and some B lymphocytes transformed by Abelson murine leukemia virus (A-MuLV). This antigen was expressed on many pre-B and B cell lymphomas, but not on A-MuLV-transformed fibroblasts, T cell lymphomas, or myelomonocytic leukemias, gp160(6C3) was expressed by most early B-lineage spontaneous tumors, and early B tumors induced by replication-defective MuLV-containing oncogenes the products of which are associated with the cytoplasmic aspect of the plasma membrane, i.e., fes, abl, H-ras, bas, src, erbB, and Cas NS-1. By comparison, none of the early B lineage lymphomas induced by the "nuclear" oncogene avian v-myc MuLV, or arising in mice transgenic for a murine c-myc gene, or later B cell lineage stages bearing translocations of the c-myc locus expressed this antigen.

Genital hygiene practices of fishermen targeted for a topical microbicide intervention against sexually transmitted infections in Kisumu, Kenya.

Research on hygiene has been relatively limited in the current era of rigorous observational studies and clinical trials. We set out to investigate the perception and practices of genital hygiene among fishermen working on the beaches along Lake Victoria, targeted for a topical male microbicide hygiene intervention. We conducted 12 focus group discussions involving fishermen (n = 130), recording the discussions in Dholuo (the local language) and transcribing them verbatim before translating into English. Transcripts were double-coded and analysed using constant comparative analysis. Despite easy access to lake water and recognition of a link that may exist between poor genital hygiene and the risk of penile infection and poor sexual relationships, few fishermen regularly washed their genitalia due to fear/embarrassment from cleaning their genitalia in public, traditional Luo beliefs such as that washing with soap would reduce the fish catch, lack of time because of their busy schedules, laziness and lack of responsibility, and excessive consumption of alcohol and illicit drugs. Hygiene practices of the fishermen were poor and could contribute to genital infections including sexually transmitted infections. Given the fishermen's poor genital hygiene practices, they may benefit from hygiene intervention, including that provided by penile microbicides, which can be applied in the privacy of their bedrooms.

A new ATP-binding fold in actin, hexokinase and Hsc70.

One of a cell biologist's favourite occupations is to discover the proteins that perform newly described functions in the cell. Very often lately, this has resulted in the identification of protein families whose related amino acid sequences reflect similar functions, but can proteins with totally unrelated sequences have similar structures and functions? In this review, Ken Holmes, Chris Sander and Alfonso Valencia describe the structural similarities between three well-known proteins that have no readily detectable primary sequence similarities but for which X-ray crystallography has revealed very similar structures. A comparison of their structures provides insights into their common mechanisms of action and into protein evolution, and has been used to detect related proteins in sequence data bases.

On the role of microtubules in movement and alignment of nuclei in virus-induced syncytia.

Infection of baby hamster kidney (BHK21-F) cells with the parainfluenza virus SV5 causes rapid and extensive cell fusion. Time-lapse cinematography shows that when cells fuse, their nuclei migrate straight to the center of the syncytium at rates of 1-2 micro/min. Nuclei are often arranged in long, tightly packed, parallel rows in syncytia derived from the fibroblastic BHK21-F cells. Polarization microscopy shows birefringent material between and parallel to these rows of nuclei, and electron microscopy shows bundles of cytoplasmic microtubules, approximately 250 A in diameter, and filaments, approximately 80 A in diameter, parallel to and between the rows of nuclei. Colchicine treatment causes disappearance of microtubules from BHK21-F cells and an apparent increase in the number of 80-A filaments. Although colchicine-treated, SV5-infected cells fuse, their nuclei do not migrate or form rows but remain randomly scattered through the syncytial cytoplasm. Incubation at 4 degrees C does not disrupt microtubules in BHK21-F cells. Rows of nuclei have been isolated from SV5-induced syncytia, and the nuclei in them have been found to be intimately associated with microtubules but not with other cytoplasmic structures. These results suggest that microtubules demarcate cytoplasmic channels through which nuclei migrate and that they may also be involved in the mechanism of nuclear movement.

In vivo analysis of glial cell phenotypes during a viral demyelinating disease in mice.

C57 BL/6N mice injected intracranially with the A59 strain of mouse hepatitis virus exhibit extensive viral replication in glial cells of the spinal cord and develop demyelinating lesions followed by virus clearing and remyelination. To study how different glial cell types are affected by the disease process, we combine three-color immunofluorescence labeling with tritiated thymidine autoradiography on 1-micron frozen sections of spinal cord. We use three different glial cell specific antibodies (a) to 2',3' cyclic-nucleotide 3' phosphohydrolase (CNP) expressed by oligodendrocytes, (b) to glial fibrillary acidic protein (GFAP) expressed by astrocytes, and (c) the O4 antibody which binds to O-2A progenitor cells in the rat. These progenitor cells, which give rise to oligodendrocytes and type 2 astrocytes and react with the O4 antibody in the adult central nervous system, were present but rare in the spinal cord of uninfected mice. In contrast, cells with the O-2A progenitor phenotype (O4 + only) were increased in number at one week post viral inoculation (1 WPI) and were the only immunostained cells labeled at that time by a 2-h in vivo pulse of tritiated thymidine. Both GFAP+ only and GFAP+, O4+ astrocytes were also increased in the spinal cord at 1 WPI. Between two and four WPI, the infected spinal cord was characterized by the loss of (CNP+, O4+) oligodendrocytes within demyelinating lesions and the presence of O-2A progenitor cells and O4+, GFAP+ astrocytes, both of which could be labeled with thymidine. As remyelination proceeded, CNP immunostaining returned to near normal and tritiated thymidine injected previously during the demyelinating phase now appeared in CNP+ oligodendrocytes. Thus O4 positive O-2A progenitor cells proliferate early in the course of the demyelinating disease, while CNP positive oligodendrocytes do not. The timing of events suggests that the O-2A progenitors may give rise to new oligodendrocytes and to type 2 astrocytes, both of which are likely to be instrumental in the remyelination process.

In vitro analysis of the oligodendrocyte lineage in mice during demyelination and remyelination.

A demyelinating disease induced in C57B1/6N mice by intracranial injection of a coronavirus (murine hepatitis virus strain A59) is followed by functional recovery and efficient CNS myelin repair. To study the biological properties of the cells involved in this repair process, glial cells were isolated and cultured from spinal cords of these young adult mice during demyelination and remyelination. Using three-color immunofluorescence combined with [3H]thymidine autoradiography, we have analyzed the antigenic phenotype and mitotic potential of individual glial cells. We identified oligodendrocytes with an antibody to galactocerebroside, astrocytes with an antibody to glial fibrillary acidic protein, and oligodendrocyte-type 2 astrocyte (O-2A) progenitor cells with the O4 antibody. Cultures from demyelinated tissue differed in several ways from those of age-matched controls: first, the total number of O-2A lineage cells was strikingly increased; second, the O-2A population consisted of a higher proportion of O4-positive astrocytes and cells of mixed oligodendrocyte-astrocyte phenotype; and third, all the cell types within the O-2A lineage showed enhanced proliferation. This proliferation was not further enhanced by adding PDGF, basic fibroblast growth factor (bFGF), or insulin-like growth factor I (IGF-I) to the defined medium. However, bFGF and IGF-I seemed to influence the fate of O-2A lineage cells in cultures of demyelinated tissue. Basic FGF decreased the percentage of cells expressing galactocerebroside. In contrast, IGF-I increased the relative proportion of oligodendrocytes. Thus, O-2A lineage cells from adult mice display greater phenotypic plasticity and enhanced mitotic potential in response to an episode of demyelination. These properties may be linked to the efficient remyelination achieved in this demyelinating disease.

Asymptomatic gonorrhea in men: caused by gonococci with unique nutritional requirements.

In a retrospective case-control study, gonococci with nutritional requirements for arginine, hypoxanthine, and uracil were recovered from 24 of 25 men with asymptomatic gonorrhea and 10 of 25 men with symptomatic gonorrhea (P = .0001). These strains represent a smaller proportion of gonococcal isolate from blacks than from whites. Asymptomatic urethral infection is important in the epidemiology of gonorrhea, particularly among whites.