bluuebunny/crossref_metadata_2025 huggingface dataset:
Digital imaging evaluation of the scapula for prediction of endosteal implant placement in reconstruction of oromandibular defects with scapular free flaps
Authors: Solis Roberto N. , Mahaney Justin , Mohhebali Roxana , Laks Shaked , Wax Mark K. , Petrisor Daniel , Brockhoff Hans C.
Published: May 2019

Objective

Dental implant placement in scapular free flaps is challenging. This study examines the scapula with computed tomography to identify ideal locations for predictable implant placement during preoperative planning.

Methods

Sixty‐eight adult patient chest CT scans (34 men, 34 women) captured for various medical indications, were analyzed for age, height, weight, and scapula length. The lateral border of the scapula was divided into six equal segments; the midpoints of each segment (labeled proximally to distally as 1M–6M) were analyzed in cross‐section as potential recipient sites for 3.5 × 8 mm implants. Also, we present a case of a 77‐year‐old male with ameloblastoma of the mandible who underwent patient specific planning and received a scapular free flap with dental implant placement.

Results

There was greater bone availability in males with a mean depth of 8.3 ± 2.8 versus 5.1 ± 3.3 mm in females (p < .01). The proximal portion (1M) of the scapula in males and females had depths of 11.3 ± 1.5 and 9.5 ± 2.3 mm, respectively. Males had depths of 8.4 ± 3.0 in M3, 9.7 ± 1.7 in M4, and 8.9 ± 1.2 mm in M6. Depth of bone available for patients with heights ≥165 cm versus <165 cm had means of 10.4 ± 1.3 and 8.0 ± 1.6 mm (p < .01), respectively; but showed no significant differences between BMI (BMI <25 vs. ≥25) and bone availability (6.8 ± 1.7 vs. 6.8 ± 1.6, p = .07), or age (<55 years vs. ≥55 years) and bone availability (9.8 ± 1.6 vs. 9.8 ± 1.6, p = .11). In our case, the patient received 6 cm length of scapular bone with four 4.1 × 14 mm endosteal implants, which upon osseointegration was able to receive a fixed dental prosthesis. Three years after the initial surgery, the patient has had no difficulty with his prosthesis.

Conclusion

In females the most proximal portion of the scapula will predictably accommodate a dental implant, while males have multiple sites including the proximal, middle, and distal portions.
Effect on clinical and neonatal outcomes of blastocelic microsuction prior to vitrification
Authors: Mitsuhata Shingo , Endo Yuji , Hayashi Momoko , Fujii Yoshitaka , Motoyama Hiroaki
Published: May 2019

Purpose

Microsuction (MS) is a technique for mechanically emptying fluid from blastocele using a microneedle. In this study, we evaluated the improvement in clinical and neonatal outcomes of vitrified blastocyst transfer programs when MS of blastocelic fluid was used before vitrification.

Methods

This was a retrospective study based on data collected between March 2014 and August 2016. A total of 317 blastocysts obtained from 211 patients were analyzed. The blastocelic fluid of expanded blastocysts was aspirated completely, and blastocysts were collapsed prior to vitrification. Clinical and neonatal outcomes of warmed blastocysts were compared.

Results

The survival rate of the MS blastocyst was significantly higher compared with the nontreatment control (98.7% vs 89.3%, OR: 9.34, 95% CI: 2.35‐36.8, P < 0.01). The rates of implantation and live birth were higher in the MS group than in the control group, but the differences were not significant. There were no differences in gestational age, birthweight, proportion of male babies, rates of cesarean section, and congenital abnormalities.

Conclusion

The MS procedure improved blastocyst survival and had little effect on further embryo development after warming.
Synthesis, Structure, and Properties of Cadmium(II) Centered Chiral Coordination Polymer based on (R)‐6‐(1‐Carboxyethoxy)‐2‐naphthoic Acid
Authors: Wang Xiu‐Wen , Huang Ji‐Han , Wang Jun‐Ku , Yu Ying‐Hui , Ma Dong‐Sheng
Published: May 2019

A cadmium chiral coordination polymer, formulated as [Cd(R‐cna)]n (1‐D) was constructed under hydrothermal method. Single‐crystal X‐ray diffraction analysis indicated that 1‐D exhibited a 2D layered structure with a point symbol of (47·63). 1‐D was further characterized by infrared spectra, powder X‐ray diffraction (PXRD), elemental analysis, thermogravimetric analysis (TGA), and circular dichroism spectra (CD). The second‐harmonic generation (SHG) property was investigated. It was also found that the luminescence of 1‐D can be quenched by iron ions and trinitrotoluene, indicating its potential application as luminescence sensing material.
II. Flipping the Classroom Inside-Out: A Systematic Theologian Discovers Contemplative Pedagogy
Authors: Robinette Brian D.
Published: May 2019

Shortly after receiving tenure in 2009, I hit a brick wall. Having poured so much energy into the tenure process, which included a large-scale book project, I found myself intellectually and emotionally spent. Uninspired and unable to gain traction with another major research project during my post-tenure sabbatical, I felt I was wandering through a desert. I had heard rumors about the “post-tenure blues,” but I somehow imagined myself immune.
The Sayings Gospel Q and the Quest of the Historical Jesus: A Response to John S. Kloppenborg
Authors: Koester Helmut
Published: May 2019

Is it possible to work back from Matthew and Luke to the final redaction of Q, from there to the earliest composition of Q, and thus ultimately to the historical Jesus? John Kloppenborg's article skillfully presents the difficulties and perils of such a procedure. I shall comment only on the second part of his paper; there is little to dispute with respect to the first part, which is an illuminating review of the role of Q (and other sources) in the search for the historical Jesus during the last two centuries. At the end, I shall offer some suggestions that may help to solve the conundrum of the historical Jesus.
The Sayings Gospel Q and the Quest of the Historical Jesus: A Response to John S. Kloppenborg
Authors: Cameron Ron
Published: May 2019

John Kloppenborg's article is a superb example of why studies of the gospel tradition, including the Sayings Gospel Q, should be important to students of religion as well as of early Christianity. Beginning with the work of Hermann Samuel Reimarus, whose last anonymous and posthumously published essay on “The Intention of Jesus and His Disciples” inaugurated both the modern quest of the historical Jesus and the origins of the synoptic problem, Kloppenborg traces in an exemplary way the twists and turns of a restless biblical scholarship that continues to struggle with the interpretative challenge laid down by Reimarus. From the pioneering studies of David Friedrich Strauss, Ferdinand Christian Baur, and the Tubingen school, through the detailed analyses of Heinrich Julius Holtzmann, Bernhard and Johannes Weiss, and Adolf von Harnack, to the modern research initiated by Heinz Eduard Tödt, James M. Robinson, Helmut Koester, and Dieter Lührmann, Kloppenborg presents an archaeology of the discipline. His mastery of both primary texts and secondary scholarship demonstrates what is required of anyone who wishes to earn the right to have an opinion.
The Phoenix in Rabbinic Literature
Authors: Niehoff M. R.
Published: May 2019

Contact between cultures is a complex phenomenon that often involves accepting foreign ideas until these become new ways of self-expression. The case of the phoenix is of special interest, in this respect, because in antiquity it was associated with the sun temple at Heliopolis and miraculous forms of rebirth. The phoenix motif also appears in a variety of early Jewish and Christian writings, thus allowing for a comparative appreciation of its rabbinic reception. In light of these other intercultural encounters, it becomes clear that the rabbis were familiar with the details of the Hellenistic phoenix myths, and not only adapted the story to their own values but even enhanced its mythological dimension. In this way, the rabbis continued the Hellenistic practice of reactivating an ancient Egyptian myth. In contrast to the symbolic approach of early Christianity, the rabbis characteristically chose to accommodate the phoenix on a literal level, interpreting it mythopoeically, that is, by creating myth. Their interpretation of the phoenix moreover illuminates important, yet hitherto unnoticed aspects of rabbinic mythology.
Withdrawing from the Desert: Pachomius and the Development of Village Monasticism in Upper Egypt
Authors: Goehring James E.
Published: May 2019

In a recent article entitled “Le monachisme égyptien et les villes,” Ewa Wipszycka cataloged for the later Byzantine period the abundant evidence of monastic habitation in or adjacent to the towns and villages of Egypt as well as in or on the margins of the cultivated land. Her analysis, which begins after the late third- to fourth-century formative period of Antony, Pachomius, and the Lower Egyptian semi-anchoritic centers in Nitria, Scetis, and Cellia, supplies convincing evidence of the rhetorical selectivity employed in the portrayal of Egyptian monasticism by the authors of the literary sources. In the literary texts, the dominance of monastic sites located in places of solitude generates a monastic geography of physical isolation. While acknowledging this dominance in the literature, Wipszycka draws together the infrequent literary references and the more numerous documentary examples of less physically isolated and more socially integrated monastic centers. The resulting picture of Egyptian monasticism is spatially and socially more complex than that derived from the literary sources alone.
‘Women's Religion’ and Second-Century Christianity
Authors: McKechnie Paul
Published: May 2019

Nothing is as problematic in contemporary work on the early Christian Church as Orthodoxy. P. Henry's 1980 conference paper ‘Why is contemporary scholarship so enamoured of ancient heretics?’ outlined the situation, saying, ‘we have moved from historical criticism through historical even-handedness to historical advocacy. The historian is not content to assure the heretics a fair hearing; the historian has become an advocate in their cause. We have done an about-face from Tertullian'sDe praescriptione haereticorumtoDe praescriptione patrum’. From ‘ruling-out-of-court of the heretics’ to, in Henry's phrase, ‘ruling-out-of-court of the Fathers’.
Londoners and London Mendicants in the Late Middle Ages
Authors: Röhrkasten Jens
Published: May 2019

Much attention has been paid to the role and functions of the mendicant orders in their urban environment. Among the topics discussed have been the friars' importance for urban development, their coexistence with other religious institutions, their economic practices and their relations with the secular authorities. As far as their spiritual and social significance is concerned their spectacular success and rapid development in the thirteenth century are generally accepted. There were some setbacks, particularly in towns where the Dominicans or Franciscans became involved in the suppression of heresy, but these had little impact on the rapid expansion of the orders. Members from all social groups, academics as well as aristocrats, merchants and artisans as well as the poor, felt the attraction of their sermons and way of life, some to such an extent that they decided to join one of the orders. But while the attraction of the mendicant ideal in the decades following the friars' arrival is undisputed, the problem of their importance for the religious life of the late medieval urban population is far more difficult to discuss. While there are assertions that the friars remained particularly popular, the orders' decline and their need of reform were already obvious in the fourteenth century and the various efforts to bring about a reinvigoration confirm this impression. In the fifteenth century famous mendicant preachers from Vincent Ferrer and Bernardino of Siena to Girolamo Savonarola attracted large crowds in many parts of Europe, but was this indicative of the population's general attitude towards the orders? Were the mendicants still perceived by the people as responding to their spiritual needs? How did the public react to signs of decadence, to disputes among the brothers? A general answer to such questions needs to be based on a large number of local studies and this is still a task for the future.
Travail of a Broken Family: Evangelical Responses to Pentecostalism in America, 1906–1916
Authors: Wacker Grant
Published: May 2019

Early pentecostals thought the world of themselves and they assumed that everyone else did too. Not always positively, of course, but frequently, and with secret envy. In one sense it is difficult to imagine how pentecostals could have been more wrong. Till the 1950s most Americans had never heard of them. A handful of observers within the established Churches noticed their existence, and maybe a dozen journalists and scholars took a few hours to try to figure out why a movement so manifestly backward could erupt in the sunlit progressivism of the early twentieth century. But for the American public as a whole, that was about all there was. In another sense, however, pentecostals' extravagant assessment of their own importance proved exactly right. Radical evangelicals, pentecostals' spiritual and in many cases biological parents, marshalled impressive resources to crush the menace in their midst. Abusive words flew back and forth for years, subsiding into sullen silence only in the 1930s. Things improved somewhat after World War II, but even today many on both sides of the canyon continue to eye the other with fear and suspicion.
Fossil Decapod Crustaceans from the Jagüel and Roca Formations (Maastrichtian–Danian) of the Neuquén Basin, Argentina
Authors: Feldmann Rodney M. , Casadío Silvio , Chirino-Gálvez Luis , Aguirre-Urreta María
Published: May 2019

Ten species of macruran, anomuran, and brachyuran decapod crustaceans, arrayed in eight families, were collected from seven localities in the Jagüel and Roca Formations, west-central Argentina. All of the decapods were collected from the Maastrichtian Jaqüel Formation and a part of the Roca Formation dated as Maastrichtian–Danian. All but one of the taxa,Xanthilites gerthiGlaessner, represent first occurrences in the unit and six had not been described previously from Argentina. Six taxa,Thaumastoplax rocaensisn. sp.,Proterocarcinus lophosn. gen. and sp.,Lobonotus lobulatan. sp.,Glyphithyreus wichmannin. sp., andCostacopluma australisn. sp. are new. Comparison of the fauna with Cretaceous and Paleogene faunas in Chile, Antarctica, and New Zealand indicates that the Argentinian fauna was strongly influenced by dispersal from lower latitude, Atlantic and Tethyan sources in marked contrast to the high latitude, Pacific affinities of the other faunas. There is no evidence that the Argentinian brachyuran fauna was seriously affected by the K–T extinction event. Seven of the genera from the Roca Formation are known from Cretaceous and Paleogene rocks.
Genetic variability in parasites and host—parasite interactions
Authors: Thompson R. C. A. , Lymbery A. J.
Published: May 2019

We have examined genetic variability in parasites in the context of ecological interactions with the host. Recent research onEchinococcus, GiardiaandCryptosporidiumhas been used to illustrate: (i) the problems that parasite variability and species recognition pose for understanding the complex and often controversial relationship between parasite and host occurrence; (ii) the need for accurate parasite characterization and the application of appropriate molecular techniques to studies on parasite transmission if fundamental questions about zoonotic relationships and risk factors are to be answered; (iii) our lack of understanding about within-host interactions between genetically heterogeneous parasites at the inter-and intraspecific levels, and the significance of such interactions with respect to evolutionary considerations and the clinical outcome of parasite infections. If advances in molecular biology and mathematical ecology are to be realized, we need to give serious consideration to the development of appropriate species concepts and in vivo systems for testing the predictions and assumptions of theoretical models.
Host genetics and infectious disease
Authors: Weatherall D. J.
Published: May 2019

Recent work on the inheritance of susceptibility to malaria suggests that, over what may have been a relatively short evolutionary period, a remarkably diverse series of gene families have been modified in response to the selective drive of this single infection. The phenotype consequences are not confined to the red cell, but involve the immune system, cytokines and many other systems. It seems likely that the mechanisms of variation in genetic susceptibility to other infective agents will reflect at least a similar degree of complexity and, if the selective pressures have been present for longer periods of our evolutionary history, may be even more diverse. This may have important implications for work directed at trying to define susceptibility loci for current infectious and non-infectious diseases.
Influence of host and parasite genotypes on immunological control ofTheileriaparasites
Authors: Morrison W. I.
Published: May 2019

Infections withTheileria parvain the African buffalo are invariably asymptomatic, whereas infections in cattle usually result in clinical disease, the severity of which varies in different populations of cattle. The parasite exhibits antigenic heterogeneity, which in cattle manifests as differences between parasite strains in their cross-protective properties. A series of studies on T cell responses toT. parvain cattle have demonstrated that class I MHC-restricted cytotoxic T lymphocytes (CTL), specific for parasitized lymphoblasts, are important mediators of immunity. Cytotoxic T cell responses frequently display parasite strain-restricted specificities which appear to correlate with the capacity of strains to cross-protect. The strain specificity of CTL responses varies in animals immunized with the same parasite strain and is influenced by both host and parasite genotype. Recent studies have provided evidence that there is competition between epitopes for induction of CTL responses, which can result in a bias to strain-specific epitopes. These properties of the CTL response have important implications for vaccination. Thus, in designing a vaccine, it may be possible, by selecting parasite proteins containing appropriate CTL epitopes, to generate CTL responses that protect against a wide range of parasite strains. Although there are no comparable data on CTL responses in the buffalo, it is considered that the features of the immune response described for cattle would be advantageous for survival of parasite populations in the buffalo. Specifically, a bias in the immune responses to strain-specific determinants should favour establishment of infection in buffalo already carrying the parasite and allow fluctuation in the levels of different parasite strains during the course of persistent infection.
Genetic susceptibility to leishmanial infections: studies in mice and man
Authors: Blackwell J. M.
Published: May 2019

Two important recent advances inLeishmaniaimmunology are: (i) the demonstration of a dramatic dichotomy in T helper 1 versus T helper 2 subset expansion leading to protection versus disease exacerbation; and (ii) analysis of the macrophage activation pathways leading to enhanced intracellular killing of parasites, in particular the tumour necrosis factor α (TNFα)-dependent sustained induction of the inducible nitric oxide synthase gene (Nos2) leading to the generation of large amounts of nitric oxide (NO). Given the broad spectrum of disease phenotypes in human leishmaniasis, one might predict that a genetic defect at any key point in this macrophage activation pathway and/or in pathways leading to activation of different T cell subsets, and the latter may be a pleiotropic effect of the former, will contribute to disease susceptibility. By studying disease in genetically-defined inbred mouse strains, it has been possible to identify 5 regions of the murine genome carrying leishmanial susceptibility genes. The genes include: (i)Scl-2(mouse chromosme 4/human chromosome 9p; candidate Janus tyrosine kinase 1) controlling a unique no lesion growth resistance phenotype toLeishmania mexicana; (ii)Scl-1(distal mouse chromosome 11/human 17q; candidatesNos2, Sigje, MIP1α, MIP1β) controlling healing versus non-healing responses toL. major; (iii) the ‘T helper 2’ cytokine gene cluster (proximal murine chromosome 11/human 5p; candidates IL4,5,9) controlling later phases ofL. majorinfection; (iv) the major histocompatibility complex (MHC: H-2 in mouse, HLA in man: mouse chromosome 17/human 6p; candidates class II and class III including TNFα/β genes); and (v)Nramp1, the positionally cloned candidate for the murine macrophage resistance geneIty/Lsh/Bcg(mouse chromosome 1/human 2q35). This review examines these 5 regions and the candidate genes within them, reflecting on their current status as candidates for human disease susceptibility genes.
Inheritance of Acetyl-CoA Carboxylase Inhibitor Resistance in Wild Oat (Avena fatua)
Authors: Murray Bruce G. , Morrison Ian N. , Brûlé-Babel Anita L.
Published: May 2019

Resistance to fenoxaprop-P and other aryloxyphenoxypropionate and cyclohexanedione herbicides in the wild oat population, UM1, is controlled by a single, partially dominant, nuclear gene. In arriving at this conclusion, parents, F1hybrids, and F2plants derived from reciprocal crosses between UM1 and a susceptible wild oat line, UM5, were treated with fenoxaprop-P over a wide range of dosages. Based on these experiments, a dosage of 400 g ai ha−1fenoxaprop-P was selected to discriminate between three response types. At this dosage, susceptible plants were killed and resistant plants were unaffected, whereas plants characterized as intermediate in response were injured but recovered. Treated F2plants segregated in a 1:2:1 (R, I, S) ratio, indicative of single nuclear gene inheritance. This was confirmed by selfing F2plants and screening several F3families. Families derived from intermediate F2plants segregated for the three characteristic response types, whereas those derived from resistant F2plants were uniformly resistant. Chisquare analysis indicated the F2segregation ratios fit those expected for a single partially dominant nuclear gene system. In addition, F2populations from both crosses were screened with a mixture of fenoxaprop-Pand sethoxydim. The dosages of both herbicides (150 g ai ha−1fenoxaprop-P and 100 g ha−1sethoxydim) were sufficient to control only susceptible plants. Treated F2populations segregated in a 3:1 (R:S) pattern, thereby confirming that resistance to the two chemically unrelated herbicides results from the same gene alteration.
Analysis of Spatial Distribution of Common Lambsquarters (Chenopodium album) in No-Till Soybean (Glycine max)
Authors: Cardina John , Sparrow Denise H. , McCoy Edward L.
Published: May 2019

The nonuniform spatial distribution of weeds complicates sampling, modeling, and management of weed populations. Principles of a rational approach to analysis of weed spatial distribution, combining classical and spatial statistics, are presented using data for cumulative emergence of common lambsquarters in no-tillage soybean fields in 1990 and 1993. Classical statistics, dispersion indices, mean/variance relationships, and frequency histograms confirmed that raw and loge-transformed data were not normally distributed, that populations were aggregated, and that large-scale trends in population means violated assumptions of spatial statistics. Detrending was accomplished by median polishing loge-transformed data and confirmed by evaluation of standardized residuals and frequency histograms. Detrended residuals were used to construct omni-directional and uni-directional semivariograms to describe the spatial structure of the populations. A spherical model fit to the data was verified by cross validation. Semivariograms showed that common lambsquarters density was spatially autocorrelated at distances to 16 m, with more than 30% of the variance in density due to distance between field locations. Comparisons of kriged estimates and their standard deviations with and without detrending indicated that estimates using detrended data were more appropriate and more precise. Kriged estimates of common lambsquarters density were used to draw contour maps of the populations.
Utility of Nuclear Magnetic Resonance for Determining the Molecular Influence of Citric Acid and an Organosilicone Adjuvant on Glyphosate Activity
Authors: Thelen Kurt D. , Jackson Evelyn P. , Penner Donald
Published: May 2019

In the discipline of Weed Science, nuclear magnetic resonance (NMR) has been used extensively for obtaining structural information on herbicide compounds in the areas of herbicide synthesis, metabolism, and environmental degradation. However, little research has been published with regard to the utilization of NMR in determining molecular interactions in the spray solution. The molecular influence of citric add and an organosilicone adjuvant on glyphosate was analyzed with NMR spectrometry.14C-glyphosate absorption studies showed a decrease in glyphosate absorption by sunflower when Ca2+was added to the spray solution. This absorption antagonism was overcome with the inclusion of an organosilicone adjuvant.1H-NMR was used to stow that the organosilicone adjuvant did not directly interact with the glyphosate molecule nor did it prevent the formation of Ca-glyphosate. Citric add was effective in overcoming the Cat2+antagonism of glyphosate activity when the citric add concentration was 2× or 4× the Ca2+molar concentration based on plant fresh weight and plant height, respectively.1H-NMR was utilized to show that citric acid reacted with Ca2+in solution to produce Ca-citrate and prevent the formation of Ca-glyphosate. NMR was an effective technique for characterizing chemical interactions among the spray solution components.
Cellular mechanisms influence differential glyphosate sensitivity in field bindweed (Convolvulus arvensis) biotypes
Authors: Westwood James H. , Weller Stephen C.
Published: May 2019

Biotypes of field bindweed that vary in sensitivity to glyphosate were studied to determine the physiological or biochemical bases for these differences. Studies con ducted using whole plants and in vitro cultured shoots identified several potentially important differences between the most tolerant (biotype 4) and most susceptible (biotype 1) biotypes. Biotype 4 plants had greater 3-deoxy-D-arabino-heptulosonate-7-phosphate synthase (DAHPS) activity and higher concentrations of phenolic compounds, indicating greater shikimate pathway activity than biotype 1. This may reflect a higher growth ability of biotype 4, as observed in shoot cultures.5-Enolpyruvylshikimate-3-phosphate synthase (EPSPS) activity in whole plants increased in all parts of biotype 4 by 7 d after a glyphosate treatment of 1.1 kg ae ha−1, whereas activities in biotype 1 plants did not increase at any time. However, this may not be the only mechanism of glyphosate tolerance because EPSPS activity in cultured shoots of both biotypes increased equally in response to glyphosate, even though biotype 4 shoots were able to survive and grow on a glyphosate-containing medium that inhibited growth of biotype 1 shoots. We propose that multiple mechanisms operating at a cellular/metabolic level combine to enable biotype 4 to tolerate higher glyphosate rates than biotype 1.
Field evaluation of soybean (Glycine max) genotypes for weed competitiveness
Authors: Bussan Alvin J. , Burnside Orvin C. , Orf James H. , Ristau Eric A. , Puettmann Klaus J.
Published: May 2019

In the first of 2 field studies, weed biomass and soybean seed yield were used to evaluate 16 soybean genotypes for competitive ability against 12 weed species at Rosemount, MN, in 1992 and 1993. The yield and ranking of soybean genotypes often varied with the weed species. Grass weed species reduced yields the most, and small-seeded broadleaf weeds reduced yields the least across years. ‘Parker’ was highly competitive, as it suppressed weed biomass and produced high soybean yield. ‘Kato,’ ‘Kasota,’ ‘Dawson,’ and ‘Glenwood’ minimized weed biomass and maintained soybean yield while in competition with grass weeds but yielded poorly relative to other soybean genotypes in weed-free conditions. ‘Lambert’ produced high soybean yield in weed-free conditions, but yield dropped markedly when in competition with grass weeds. ‘Grande,’ ‘Heifeng 25,’ and ‘Norman’ soybeans were poor competitive genotypes in weedy situations and low yielding in weed-free conditions. A 2nd field study conducted at Rosemount and St. Paul, MN, during 1993 evaluated 16 soybean genotypes under 4 levels and durations of weed pressure for weed competitiveness. Parker, ‘Sturdy,’ and M89-794 were most competitive in suppressing weed biomass and producing high yields. Lambert yielded fairly well but allowed high weed biomass. M89-1743, M89-1006, ‘Archer,’ and ‘Ozzie’ yielded poorly and did not sup press weed biomass production. No relationship was found between weed competitiveness and soybean canopy area, height, and volume measured 30–45 d after planting (DAP).
Common cocklebur (Xanthium strumarium) interference with peanut (Arachis hypogaea)
Authors: Royal Stanley S. , Brecke Barry J. , Colvin Daniel L.
Published: May 2019

Studies were conducted in Florida to evaluate interference of common cocklebur with peanut. Peanut yield reduction ranged from 0 to 88% for common cocklebur densities of 0–32 plants 8 m−1of peanut row, and predicted loss was similar under normal moisture conditions. When moisture levels were above normal, the impact on yield was 9–24% less than when soil moisture was normal. Common cocklebur caused peanut yield loss if allowed to interfere for more than the first 2 wk after crop emergence, and peanut had to be common cocklebur free for at least 12 wk to prevent a yield reduction. These results show common cocklebur to be more competitive with peanut than other weeds evaluated previously.
Weed seed bank emergence across the Corn Belt
Authors: Forcella Frank , Wilson Robert G. , Dekker Jack , Kremer Robert J. , Cardina John , Anderson Randy L. , Alm David , Renner Karen A. , Harvey R. Gordon , Clay Sharon , Buhler Douglas D.
Published: May 2019

Field experiments, conducted from 1991 to 1994, generated information on weed seedbank emergence for 22 site-years from Ohio to Colorado and Minnesota to Missouri. Early spring seedbank densities were estimated through direct extraction of viable seeds from soil cores. Emerged seedlings were recorded periodically, as were daily values for air and soil temperature, and precipitation. Percentages of weed seedbanks that emerged as seedlings were calculated from seedbank and seedling data for each species, and relationships between seedbank emergence and microclimatic variables were sought. Fifteen species were found in 3 or more site-years. Average emergence percentages (and coefficients of variation) of these species were as follows: giant foxtail, 31.2 (84%); velvetleaf, 28.2 (66); kochia, 25.7 (79); Pennsylvania smartweed, 25.1 (65); common purslane, 15.4 (135); common ragweed, 15.0 (110); green foxtail, 8.5 (72); wild proso millet, 6.6 (104); hairy nightshade, 5.2 (62); common sunflower, 5.0 (26); yellow foxtail, 3.4 (67); pigweed species, 3.3 (103); common lambsquarters, 2.7 (111); wild buckwheat, 2.5 (63), and prostrate knotweed, 0.6 (79). Variation among site-years, for some species, could be attributed to microclimate variables thought to induce secondary dormancy in spring. For example, total seasonal emergence percentage of giant foxtail was related positively to the 1st date at which average daily soil temperature at 5 to 10 cm soil depth reached 16 C. Thus, if soil warmed before mid April, secondary dormancy was induced and few seedlings emerged, whereas many seedlings emerged if soil remained cool until June.
Broom snakeweed (Gutierrezia sarothrae) dispersal, viability, and germination
Authors: Wood Ballard L. , McDaniel Kirk C. , Clason Dennis
Published: May 2019

Broom snakeweed achene dispersal was monitored by placing surface-level traps outwards in the cardinal directions from 12 plants and collecting the achenes weekly or biweekly from September 1993 until seeds were no longer retained by the plants after 42 wk. About 50% of the achenes dispersed between October and December. Especially high numbers of achenes were dislodged during periods of intense winter winds and rains, with 78% of the seed placed into the east tray and 86% falling within 50 cm of the parent plant. Achene production averaged 3,928 (± 1,146) per plant in 1993 and 2,036 (± 987) per plant in 1994. Achenes collected over time directly from the inflorescence and achenes stored in nylon packets on the soil surface averaged 82% viability during fall and winter. Achene viability declined rapidly in late spring, and few remained viable before the next seed crop. Greenhouse experiments compared the influence of water application interval and water amount on broom snakeweed germination and seedling survival. Treatments consisted of 4 water intervals: daily, 5-d, 10-d, and 15-d intervals; and 4 water amounts: field capacity (1/1 fc), 3/4 fc, 1/2 fc, and 1/4 fc. Germination was 52% at daily 1/1 fc, and no seed germinated at daily 1/4 fc. Data suggest that optimum germination occurs when soils are maintained at a minimum soil matric potential (Ψm) > −180 kPa for at least 4 d. Optimum Ψm for seedling survival appears to range between −300 and −900 kPa, while seedling mortality would generally be expected with a Ψm of > −1800 kPa.
Seed production and seedbank dynamics in subthreshold velvetleaf (Abutilon theophrasti) populations
Authors: Cardina John , Norquay Heather M.
Published: May 2019

The impact of seed production by subthreshold weed populations on future weed problems has impeded the adoption of integrated pest-management principles for weed management. Studies were conducted in fields with no velvetleaf history to determine how seedbanks and seedling populations change following seed production 1 yr or 5 consecutive yr in plow-disk and no-tillage corn. Cumulative seed production by 0.19 velvetleaf plants m−2increased in a linear fashion from 1989 to 1994, with annual additions averaging from 330 seeds m−2for velvetleaf in corn to 2,500 seeds m−2for velvetleaf without competition from corn. Five-year cumulative seed production was 1,480 seeds m−2in plow-disk and 1,810 seeds m−2in no-till corn. In no-till corn, 42 velvetleaf seedlings m−2emerged the 1st year after the 1989 seed rain, but only 35 seedlings m−2emerged over the next 4 yr. In plow-disk plots, annual emergence averaged 12 seedlings m−2. Five years after the 1989 seed rain, the proportion of seeds lost to emergence was about 20% in both tillage treatments. Where velvetleaf seeds were allowed to return to the soil every year, cumulative seedling emergence was lower in plow-disk than in no-till corn, with total emergence of 70 and 360 seedlings m−2, respectively, after 5 yr. Seedbank numbers ranged from 10 seeds m−25 yr after a single seed rain (290 seeds m−2) by velvetleaf in plow-disk corn to 1,020 seeds m−2following 5 consecutive yr of seed rain where 12,580 seeds m−2were returned without corn competition in no-till. Seedbank samples in the fall of the 5th year had 69 to 98% fewer seeds than were accounted for by cumulative seed rain and seedling emergence, with greater apparent seed losses in plow-disk corn than in no-till corn. Over 90% velvetleaf control would be required annually to maintain subthreshold populations for 5 yr following a single seed rain. By comparison, over 95% control would be required annually to maintain subthreshold populations where velvetleaf seed return is permitted each year.
Interference between hemp sesbania (Sesbania exaltata) and soybean (Glycine max) in response to irrigation and nitrogen
Authors: King C. Andy , Purcell Larry C.
Published: May 2019

Soybean yield loss from weed interference depends upon weed density and competitiveness of crop and weed species in response to environment. Soil water availability and nitrogen fertility were evaluated for their effect on competitiveness of individual species in field experiments. Early-season temperatures in 1995, which were cool compared to 1994, slowed hemp sesbania growth without affecting soybean growth. This resulted in negligible competition with soybean by hemp sesbania at densities of 3 or 6 plants m−2. In 1994, hemp sesbania grew above the soybean canopy, decreasing soybean light interception 29 to 68%, and reducing soybean yield 30 to 48%. Fertilizer nitrogen increased soybean competitiveness, as indicated by biomass production, only in irrigated plots with hemp sesbania at 3 m−2, but did not affect soybean yield. Apparently, competition for light is a primary cause of soybean yield loss from hemp sesbania infestations. In growth chamber studies, simulating temperatures from the field, hemp sesbania growth was stimulated more by warm temperatures than was soybean. Hemp sesbania and soybean dry weights increased 4.4- and 2.7-fold, respectively, at 30/20 C day/night temperatures compared to 25/15 C.
Emergence and survival of horseweed (Conyza canadensis)
Authors: Buhler Douglas D. , Owen Micheal D. K.
Published: May 2019

Horseweed emergence and survival were evaluated in no-tillage soybean and corn at Rosemount, MN, and Ames, IA, from the fall of 1992 through the summer of 1995. Most of the horseweed at both locations emerged in the fall. Winter survival of fall-emerged seedlings ranged from 59 to 91%. Timing and extent of horseweed emergence in spring varied by year and location. Spring emergence ranged from 5 to 32% of total emergence, with greater spring emergence at Rosemount than at Ames. Emergence occurred as late as early June at Rosemount and late May at Ames. Results indicated that horseweed may emerge well into the growing season, and spring emergence should be considered in weed management systems for no-tillage crop production.
Analysis of genetic variation in wild mustard (Sinapis arvensis) using molecular markers
Authors: Moodie Michael , Finch Robert P. , Marshall George
Published: May 2019

Genetic variation was assessed in a range of populations of wild mustard (Sinapis arvensisL.) using random amplified polymorphic DNA (RAPD) analysis. Sixty markers were used to assess the extent of genetic variation in wild mustard populations sampled throughout 12 different locations in the United Kingdom, including herbicide treated and untreated sites. In addition, selected sites were sampled over two consecutive seasons. Individual plant analysis was required, since a high degree of intra-population genetic variation was observed. The apparent extent of genetic variation in a population at one site increased when the results from two consecutive seasons were assessed. The range of genetic variation was as high in the herbicide-treated populations as in those which were untreated. Genetic diversity was maintained in populations of wild mustard where rotational cropping and herbicide use was practiced. These results confirm the utility of RAPD for the determination of genetic variation in outcrossing species where no prior genotypic knowledge is available.
Wheat (Triticum aestivum) yield reduction from common milkweed (Asclepias syriaca) competition
Authors: Yenish Joseph P. , Durgan Beverly R. , Miller Douglas W. , Wyse Donald L.
Published: May 2019

Yield loss of hard red spring wheat due to competition from common milkweed was measured in grower fields in Minnesota. Wheat yield loss was measured using the area of influence and additive competitive methods. Simple linear regression of wheat yield and percentage wheat yield loss against distance from a common milkweed shoot gaver2values of 0.013 and 0.015, respectively, indicating limited value of the area of influence model for common milkweed in spring wheat. In an additive competition model, wheat yield was reduced 47% at the highest density of 12 common milkweed shoots m−2. Coefficients of determination for percentage yield loss regressed against common milkweed shoot density were 0.548, 0.547, and 0.529 for simple linear, nonlinear rectangular hyperbolic, and linear square root function models, respectively. Regression of percentage yield loss against common milkweed biomass resulted inr2values of 0.566, 0.645, and 0.658 for simple linear, nonlinear rectangular hyperbolic, and linear square root function models, respectively. Restrictions of common milkweed density due to factors other than competition limited yield loss response to the simple linear phase of both the nonlinear rectangular hyperbolic and the linear square root function models previously described.
Identification of graminicide-resistant johnsongrass (Sorghum halepense)
Authors: Smeda Reid J. , Snipes Charles E. , Barrentine William L.
Published: May 2019

Resistance to fluazifop-P and quizalofop-P, (aryloxyphenoxypropionates) and sethoxydim (cyclohexanedione) was identified in 2 populations of johnsongrass in both field and greenhouse studies. The cropping history (1983–1991) of the sites indicated 1 or more annual applications of a graminicide (primarily fluazifop-P) since the early 1980s. Under field conditions, control of resistant seedling and rhizome johnsongrass (R91F) with fluazifop-P, quizalofop-P, fenoxaprop-ethyl, and sethoxydim was less than 35%. Clethodim provided up to 80% control of R91F. Under greenhouse conditions, ratios (R/S) of the I50values (amount of herbicide required to inhibit plant growth by 50%) of resistant (2 sites: R91F and R91S) to susceptible (S91H) seedling (20–30-cm height) plants were > 388 (fluazifop-P), > 15 (quizalofop-P), and from 2.3 (R91S) to 3.4 (R91F) (both sethoxydim). For rhizome (30–45 cm height) plants, the R/S ratios were > 388 (fluazifop-P), > 16 (quizalofop-P), and 2.8 (R91S) to 8.5 (R91F) (both sethoxydim). Labeled rates (in kg ai ha−1) of fluazifop-P (0.10 and 0.21), quizalofop-P (0.039 and 0.08), and sethoxydim (0.21 and 0.21) were applied on seedling and rhizome plants, respectively, and resulted in little or no control of resistant johnsongrass. Greenhouse studies indicated registered rates of clethodim (0.10 and 0.14 kg ai ha−1for seedling and rhizome plants, respectively) effectively controlled the resistant populations, but tolerance was measured for both seedling and rhizome plants at sublethal doses (down to 0.007 and 0.009 kg ai ha−1, respectively), with I50ratios ranging from 1.5 (R91S) to 2.1 (R91F) for seedling plants and 4.5 (R91S) to 4.8 (R91F) for rhizome plants. Control of resistant seedling and rhizome johnsongrass under field conditions was adequate with glyphosate at 0.84, glufosinate at 0.84, and sulfosate at 0.84 kg ai ha−1, indicating no cross-resistance.
Postemergence herbicide application timing effects on annual grass control and corn (Zea mays) grain yield
Authors: Tapia Larry S. , Bauman Thomas T. , Harvey Robert G. , Kells James J. , Kapusta George , Loux Mark M. , Lueschen William E. , Owen Michael D. K. , Hageman Larry H. , Strachan Stephen D.
Published: May 2019

Giant foxtail, woolly cupgrass, and wild-proso millet infest millions of hectares of land devoted to corn production in the midwestern U.S. Control of these species and effects on corn grain yield were evaluated at various timings using POST applications of nicosulfuron vs. applications of various PRE herbicides at 17 locations across the midwestern U.S. in 1992 and 1993. Nicosulfuron applied to 5 to 10 cm giant foxtail and woolly cupgrass provided greater control than that observed with selected PRE herbicides. Giant foxtail control with nicosulfuron averaged 88%, and control of woolly cupgrass averaged 77% across all sites. Nicosulfuron, applied to 5 to 10 cm wild-proso millet, provided a level of control similar to that of selected PRE herbicides. Corn grain yield was greater when giant foxtail was controlled POST with nicosulfuron vs. PRE control with selected soil-applied herbicides. Corn grain yields were similar when nicosulfuron was applied POST to 5 to 10 cm woolly cupgrass or wild-proso millet vs. PRE control of these grass weeds. Across a broad range of geographical locations, nicosulfuron, applied POST to 5 to 10 cm tall grass, provided greater or similar levels of weed control vs. the selected PRE herbicides, with no deleterious effect on grain yield.
Efficacy ofExserohilum monocerasfor the control ofEchinochloaspecies in rice (Oryza sativa)
Authors: Zhang Wenming , Watson Alan K.
Published: May 2019

Efficacy of an indigenous fungus,Exserohilum monoceras, for the control of 3Echinochloaspecies was evaluated and compared under both regulated greenhouse and screenhouse (field plots netted with 2 layers of metal mesh screening to exclude vertebrate pests) conditions. Under greenhouse conditions, an inoculum dose of 2.5 × 107conidia m−2killed all seedlings of both barnyardgrass andE. glabrescens, whereas an inoculum dose of 5.0 × 107conidia m−2was required to obtain 100% mortality of junglerice seedlings. The 1.5-leaf stage of all 3Echinochloaspecies was the most susceptible. Increasing inoculum density increased weed control efficacy on younger or olderEchinochloaseedlings. The highest level of control was observed forE. glabrescens, less for barnyardgrass, and least for junglerice. Under screenhouse conditions,Exserohilum monocerascaused more than 90% mortality ofEchinochloaspecies when the inoculum was formulated as an oil emulsion or when applied as a dry powder.
Efficacy of reduced-rate herbicide combinations in dry-seeded rice (Oryza sativa) on alluvial clay soil
Authors: Jordan David L.
Published: May 2019

Research was conducted from 1993 through 1995 to evaluate barnyardgrass control, rice yield, and estimated economic return with POST applications of propanil or propanil + molinate applied alone or with quinclorac. Herbicides were applied under a variety of water management practices and environmental conditions at rates ranging from 1.1 to 3.4, 1.7 to 5.6, and 0.17 to 0.40 kg ai ha−1for propanil, propanil + molinate, and quinclorac, respectively. Reduced-rate combinations of propanil or propanil + molinate with reduced rates of quinclorac controlled small, actively growing barnyardgrass and provided yields and estimated economic returns similar to combinations of these herbicides at higher rates when irrigated. When herbicides were applied to larger barnyardgrass, propanil + molinate at 5.6 kg ha−1was more effective than propanil at 3.4 kg ha−1or quinclorac at 0.40 kg ha−1applied alone. Propanil + molinate applied with quinclorac at 0.28 or 0.40 kg ha−1controlled barnyardgrass more effectively and provided higher yields and greater estimated economic returns than propanil at 3.4 kg ha−1, propanil + molinate at 5.6 kg ha−1, quinclorac at 0.17, 0.28, or 0.40 kg ha−1, or combinations of propanil and quinclorac.