Mechanische Unkrautregulierung in der Saatreihe von Soja

Organic cropping of soya beans mainly depends on the successful control of weeds. Hoeing in between the crop rows can be effective but the mechanical control of weeds within the crop row is difficult. Objective of this study was to investigate the effect of three machines and two combinations thereof to control two model weeds seeded directly in the crop row of soya bean. Reduction of the soil cover (%) in the crop row was evaluated after the means were applied and compared to the control treatment (hoeing between the crop rows). Results of two experiments conducted in 2007 and 2008 show that soil cover of companion plants within the crop row can be reduced up to 70 % when compared to the control treatment. Before best treatments can be recommended for the farmers, large-scale tests have to be conducted in order to improve the use of these means to keep the impact on the main crop as low as possible

Verschiedene Gründüngerpflanzen – Anbaueignung und Unkrautunterdrückung im Direktsaatsystem vor Winterweizen

In a small-plot field trial 33 green manure plants (GM) were examined for their ability to suppress weeds in a no-tillage system. A roll-chopper was used to suppress the GMs before seeding winter wheat. The success of this organic method to control GMs was compared to the standard method using a non selective herbicide. Species of the group brassicaceae, monocotyles and plant mixtures covered the soil faster, produced more biomass and suppressed weeds more efficiently than species of the group legumes and dicotyles. In spring, weed infestation in all roll-chopper treatments always exceeded economic threshold values whereas in the herbicide treatment weed infestations remained below these values. Additionally, wheat yield and density was reduced in the roll-chopper treatment compared to the herbicide treatment. Application of the roll-chopper together with a suitable GM for Swiss growing conditions will have to be improved before its introduction for no tillage agriculture in organic farming

The significance of mycorrhizal fungi for crop productivity and ecosystem sustainability in organic farming systems

Mycorrhizal fungi are widespread in agricultural systems and are especially relevant for organic agriculture because they can act as natural fertilisers, enhancing plant yield. Here we explore the various roles that mycorrhizal fungi play in sustainable farming systems with special emphasis on their contribution to crop productivity and ecosystem functioning. We review the literature and provide a number of mechanisms and processes by which mycorrhizal fungi can contribute to crop productivity and ecosystem sustainability. We then present novel results, showing that mycorrhizal fungi can be used to suppress several problematic agricultural weeds. Our results highlight the significance of mycorrhizal fungi for sustainable farming systems and point to the need to develop farming systems in which the positive effect of these beneficial soil fungi is optimally being utilized

Mechanical control of weeds within the crop row of organically grown soybeans

Despite the increasing demand for organically grown soybeans (Glycine max (L.) Merr.), this crop is barely cultivated on organic farms in Switzerland. One reason is that an economically feasible organic cultivation of soybeans mainly depends on the successful control of weeds – especially within the crop row. The aim of this study was to investigate the effect of three types of weeding machines (finger hoe = FI, torsion hoe = TO, weeder harrow = WE) and of two combinations thereof (FI+WE, TO+WE) on the control of two model weed species (Brassica x chinensis L. and Phacelia tanacetifolia L.) seeded at the same time as the soybean directly in the rows of soybeans. In all plots, including the control plots, hoeing between the rows was conducted. Experiments were conducted from 2007 to 2010 in the surrounding of Zurich (Switzerland). Soil cover (%) of the two model weed species and soybeans in the crop row was evaluated. In addition, the yield of the main crop was assessed in two growing seasons.Averaged over three years, the soil cover within the crop row was reduced after two interventions by 17 % (WE) up to 45 % (FI) for P. tanacetifolia when the machines were used alone. The combination of the machines increased the effect and resulted in the best control with FI+WE with a reduction of 60 %. A comparable effect with the same ranking of the machines was found for Brassica x chinensis. FI+WE did not only provide the highest weed control level but also showed significantly higher yields (2.91 t/ha) than the control (2.49 t/ha). The data show that the control of weeds within the row of soybeans can be successful and as a consequence also the cultivation of organically produced soybean. However, the optimal plant growth stages for the weed regulation has to coincide with ideal weather and soil conditions. Keywords: Brassica x chinensis L., Glycine max (L.) Merr., organic farming, Phacelia tanacetifolia L.Mechanische Unkrautregulierung in der Saatreihe von SojaTrotz zunehmender Nachfrage nach biologisch angebauter Soja (Glycine max (L.) Merr.) wird diese interessante Kultur in der Schweiz selten angebaut. Grund dafür ist die langsame Jugendentwicklung und die damit im Ökolandbau verbundenen Herausforderungen für eine wirtschaftliche und gleichzeitig wirksame Regulierung der Begleitflora, insbesondere in den Reihen der Soja. Ziel dieser Versuche war es, die Wirkung von drei verschiedenen Unkrautregulierungs-geräten (Fingerhacke = FI, Torsionshacke = TO, Striegel = WE) und zwei Kombinationen davon (FI+WE, TO+WE) auf zwei direkt in die Sojareihen eingesäten Pflanzenarten (Brassica x chinensis L. und Phacelia tanacetifolia L.) zu untersuchen. Die Versuche wurden von 2007 bis 2010 in der Umgebung von Zürich (Schweiz) durchgeführt. Der Bodenbedeckungsgrad (%) der beiden Pflanzenarten sowie der Hauptkultur wurde in der Sojareihe erfasst. Zusätzlich wurde in zwei Jahren der Ertrag von Soja erfasst.Im Mittel von drei Jahren konnte nach zwei Durchgängen der Bodenbedeckungsgrad von P. tanacetifolia um 17 % (WE) bis 45 % (FI) vermindert werden, wenn die Maschinen einzeln eingesetzt wurden. Die Kombination der Maschinen verstärkte den Effekt und führte im besten Verfahren zu einer Reduktion von 60 % (FI+WE). Einen vergleichbaren Effekt mit derselben Rangfolge der Verfahren wurde für Brassica x chinensis beobachtet. Das Verfahren Fingerhacke kombiniert mit dem Striegel (FI+WE) hatte nicht nur die beste unkrautunterdrückende Wirkung sondern führte zusätzlich zu einem signifikant höheren Kornertrag (2,91 t/ha) als das Kontrollverfahren (2,49 t/ha). Die Daten zeigen, dass die untersuchten Pflanzenarten in der Reihe wirksam reguliert werden können und folglich auch Soja unter biologischen Bedingungen erfolgreich angebaut werden kann. Voraussetzung ist aber, dass die mechanischen Eingriffe in einem optimalen Pflanzenstadium sowie bei guten Witterungs- und Bodenbedingungen erfolgen können. Stichwörter: Biologischer Landbau, Brassica x chinensis L., Glycine max (L.) Merr., Phacelia tanacetifolia L., Phacelia, Rübse

Uncovering modern paint forgeries by radiocarbon dating

Art forgeries have existed since antiquity, but with the recent rapidly expanding commercialization of art, the approach to art authentication has demanded increasingly sophisticated detection schemes. So far, the most conclusive criterion in the field of counterfeit detection is the scientific proof of material anachronisms. The establishment of the earliest possible date of realization of a painting, called the terminus post quem, is based on the comparison of materials present in an artwork with information on their earliest date of discovery or production. This approach provides relative age information only and thus may fail in proving a forgery. Radiocarbon (C-14) dating is an attractive alternative, as it delivers absolute ages with a definite time frame for the materials used. The method, however, is invasive and in its early days required sampling tens of grams of material. With the advent of accelerator mass spectrometry (AMS) and further development of gas ion sources (GIS), a reduction of sample size down to microgram amounts of carbon became possible, opening the possibility to date individual paint layers in artworks. Here we discuss two microsamples taken from an artwork carrying the date of 1866: a canvas fiber and a paint chip (<200 mu g), each delivering a different radiocarbon response. This discrepancy uncovers the specific strategy of the forger: Dating of the organic binder delivers clear evidence of a post-1950 creation on reused canvas. This microscale C-14 analysis technique is a powerful method to reveal technically complex forgery cases with hard facts at a minimal sampling impact

Anticholinergic and Sedative Medications Are Associated With Neurocognitive Performance of Well Treated People With Human Immunodeficiency Virus.

Background We previously showed that anticholinergic (ACH) medications contribute to self-reported neurocognitive impairment (NCI) in elderly people with human immunodeficiency virus (PWH). The current cross-sectional study further evaluated the effect of ACH and sedative drugs on neurocognitive function in PWH who underwent comprehensive neuropsychological evaluation. Methods A medication review was performed in PWH enrolled in the prospective Neurocognitive Assessment in Metabolic and Aging Cohort within the Swiss HIV Cohort Study. Neurocognitive functions were analyzed in 5 domains (motor skills, speed of information, attention/working memory, executive functions, and verbal learning memory). The effect of ACH and sedative medications on neurocognitive functioning was evaluated using linear regression models for the continuous (mean z-score) outcome and multivariable logistic regression models for the binary (presence/absence) outcome. Results A total of 963 PWH (80% male, 92% Caucasian, 96% virologically suppressed, median age 52) were included. Fourteen percent of participants were prescribed ≥1 ACH medication and 9% were prescribed ≥1 sedative medication. Overall, 40% of participants had NCI. Sedative medication use was associated with impaired attention/verbal learning and ACH medication use with motor skills deficits both in the continuous (mean z-score difference -0.26 to -0.14, P < .001 and P = .06) and binary (odds ratio [OR], ≥1.67; P < .05) models. Their combined use was associated with deficits in overall neurocognitive functions in both models (mean z-score difference -0.12, P = .002 and OR = 1.54, P = .03). These associations were unchanged in a subgroup analysis of participants without depression (n = 824). Conclusions Anticholinergic and sedative medications contribute to NCI. Clinicians need to consider these drugs when assessing NCI in PWH

Long-term Mortality in HIV-Positive Individuals Virally Suppressed for >3 Years With Incomplete CD4 Recovery

Virally suppressed HIV-positive individuals on combination antiretroviral therapy who do not achieve a CD4 count >200 cells/µL have substantially increased long-term mortality. The increased mortality was seen across different patient groups and for all causes of deat

The Incidence of AIDS-Defining Illnesses at a Current CD4 Count ≥200 Cells/µL in the Post-Combination Antiretroviral Therapy Era

The incidence of AIDS was higher in patients with a current CD4 count of 500-749 cells/µL compared to 750-999 cells/µL, but did not decrease further at higher CD4 levels. Results were similar in those virologically suppressed on combination antiretroviral therapy, suggesting immune reconstitution is incomplete until CD4 >750/µ

A Phylogenetic Analysis of Human Immunodeficiency Virus Type 1 Sequences in Kiev: Findings Among Key Populations

Background: The human immunodeficiency virus (HIV) epidemic in Ukraine has been driven by a rapid rise among people who inject drugs, but recent studies have shown an increase through sexual transmission. Methods: Protease and reverse transcriptase sequences from 876 new HIV diagnoses (April 2013–March 2015) in Kiev were linked to demographic data. We constructed phylogenetic trees for 794 subtype A1 and 64 subtype B sequences and identified factors associated with transmission clustering. Clusters were defined as ≥2 sequences, ≥80% local branch support, and maximum genetic distance of all sequence pairs in the cluster ≤2.5%. Recent infection was determined through the limiting antigen avidity enzyme immunoassay. Sequences were analyzed for transmitted drug resistance mutations. Results Thirty percent of subtype A1 and 66% of subtype B sequences clustered. Large clusters (maximum 11 sequences) contained mixed risk groups. In univariate analysis, clustering was significantly associated with subtype B compared to A1 (odds ratio [OR], 4.38 [95% confidence interval {CI}, 2.56–7.50]); risk group (OR, 5.65 [95% CI, 3.27–9.75]) for men who have sex with men compared to heterosexual males; recent, compared to long-standing, infection (OR, 2.72 [95% CI, 1.64–4.52]); reported sex work contact (OR, 1.93 [95% CI, 1.07–3.47]); and younger age groups compared with age ≥36 years (OR, 1.83 [95% CI, 1.10–3.05] for age ≤25 years). Females were associated with lower odds of clustering than heterosexual males (OR, 0.49 [95% CI, .31–.77]). In multivariate analysis, risk group, subtype, and age group were independently associated with clustering (P < .001, P = .007, and P = .033, respectively). Eighteen sequences (2.1%) indicated evidence of transmitted drug resistance. Conclusions Our findings suggest high levels of transmission and bridging between risk groups

Time to Switch to Second-line Antiretroviral Therapy in Children With Human Immunodeficiency Virus in Europe and Thailand.

Background: Data on durability of first-line antiretroviral therapy (ART) in children with human immunodeficiency virus (HIV) are limited. We assessed time to switch to second-line therapy in 16 European countries and Thailand. Methods: Children aged <18 years initiating combination ART (≥2 nucleoside reverse transcriptase inhibitors [NRTIs] plus nonnucleoside reverse transcriptase inhibitor [NNRTI] or boosted protease inhibitor [PI]) were included. Switch to second-line was defined as (i) change across drug class (PI to NNRTI or vice versa) or within PI class plus change of ≥1 NRTI; (ii) change from single to dual PI; or (iii) addition of a new drug class. Cumulative incidence of switch was calculated with death and loss to follow-up as competing risks. Results: Of 3668 children included, median age at ART initiation was 6.1 (interquartile range (IQR), 1.7-10.5) years. Initial regimens were 32% PI based, 34% nevirapine (NVP) based, and 33% efavirenz based. Median duration of follow-up was 5.4 (IQR, 2.9-8.3) years. Cumulative incidence of switch at 5 years was 21% (95% confidence interval, 20%-23%), with significant regional variations. Median time to switch was 30 (IQR, 16-58) months; two-thirds of switches were related to treatment failure. In multivariable analysis, older age, severe immunosuppression and higher viral load (VL) at ART start, and NVP-based initial regimens were associated with increased risk of switch. Conclusions: One in 5 children switched to a second-line regimen by 5 years of ART, with two-thirds failure related. Advanced HIV, older age, and NVP-based regimens were associated with increased risk of switch