Overexpression of zmm28 increases maize grain yield in the field.

Increasing maize grain yield has been a major focus of both plant breeding and genetic engineering to meet the global demand for food, feed, and industrial uses. We report that increasing and extending expression of a maize MADS-box transcription factor gene, zmm28, under the control of a moderate-constitutive maize promoter, results in maize plants with increased plant growth, photosynthesis capacity, and nitrogen utilization. Molecular and biochemical characterization of zmm28 transgenic plants demonstrated that their enhanced agronomic traits are associated with elevated plant carbon assimilation, nitrogen utilization, and plant growth. Overall, these positive attributes are associated with a significant increase in grain yield relative to wild-type controls that is consistent across years, environments, and elite germplasm backgrounds.

Project to improve storage, access and incorporation of advance care plans in a regional Australian hospital.

PROBLEM: Despite acknowledged benefits, the impact of advance care planning on usual care is inconsistent. DESIGN: Quality improvement study. SETTING: A Western Australian regional hospital. KEY MEASURES FOR IMPROVEMENT: This project aimed to create a system for storing, accessing and incorporating advance care planning documents in clinical care. STRATEGIES FOR CHANGE: Interventions over 18 months addressed four areas: medical records processes for receiving and processing advance care planning documents; information technology solutions for electronic storage and alerts; clerical staff duties in regards advance care planning documents; and clinician education. EFFECTS OF CHANGE: There was a 12-fold increase in advance care planning documents stored electronically and 100% of audited notes had correct filing of advance care planning documents with an alert in place at follow-up audit. Clinician recognition of the presence of an advance care planning document improved. Detailed examples of interventions are described. LESSONS LEARNT: Repeated exposure to different forms of advance care planning education, in conjunction with simple but effective system changes can make a difference in changing established hospital practice. Final impact of these changes on end-of-life care requires further audit.

Arginine in the FARM and SARM: A Role in Chain-Length Determination for Arginine in the Aspartate-Rich Motifs of Isoprenyl Diphosphate Synthases from Mycobacterium tuberculosis.

Isoprenyl chains are found in many important metabolites. These are derived from precursors of the appropriate length produced by isoprenyl diphosphate synthases (IDSs). The human pathogen Mycobacterium tuberculosis makes various isoprenoids/terpenoids, with important roles in their biosynthesis played by two closely related IDSs, encoded by grcC1 (Rv0562) and grcC2 (Rv0989c), with Rv0989c generating the 10-carbon precursor (E)-geranyl diphosphate (GPP), and Rv0562 the 20-carbon precursor (E,E,E)-geranylgeranyl diphosphate (GGPP). Intriguingly, while Rv0562 contains the prototypical trans-IDS first and second aspartate-rich (DDxxD) motifs (FARM and SARM, respectively), Rv0989c uniquely contains arginine in place of the second Asp in the FARM and first Asp in the SARM. Here site-directed mutagenesis of the corresponding residues in both Rv0562 and Rv0989c reveals that these play a role in determination of product chain length. Specifically, substitution of Asp for the Arg in the FARM and SARM of Rv0989c leads to increased production of the longer 15-carbon farnesyl diphosphate (FPP), while substitution of Arg for the corresponding Asp in Rv0562 leads to increased release of shorter products, both FPP and GPP. Accordingly, while the primary role of the FARM and SARM is known to be chelation of the divalent magnesium ion co-factors that assist substrate binding and catalysis, the Arg substitutions found in Rv0989c seem to provide a novel means by which product chain length is moderated, at least in these M. tuberculosis IDSs.

Greater sigmoid notch dysplasia causing elbow instability: Lateral ligament reconstruction and Stamp osteotomy.

The coronoid is one of the elbow's primary static stabilisers, and the importance of reconstruction following fracture with instability has been established. In the developing elbow, instability can lead to greater sigmoid notch dysplasia that can make reconstruction challenging. A novel technique to improve osseous stability with an opening wedge 'stamp osteotomy' reconstruction of the coronoid is described combined with a lateral ligament reconstruction, in two patients with recurrent posteromedial rotatory instability. The technique improves congruity and coverage of the greater sigmoid notch with the trochlea whilst maintaining articular cartilage. Extra-articular iliac crest bone graft is used to maintain the position with buttress plate support. The surgical technique is described and the clinical and radiographic outcome reported in two patients. Level of evidence: IV.

Arabidopsis Carboxylesterase 20 Binds Strigolactone and Increases Branches and Tillers When Ectopically Expressed in Arabidopsis and Maize.

Severe drought stress can delay maize silk emergence relative to the pollen shedding period, resulting in poor fertilization and reduced grain yield. Methods to minimize the delay in silking could thus improve yield stability. An Arabidopsis enhancer-tagged carboxylesterase 20 (AtCXE20) line was identified in a drought tolerance screen. Ectopic expression of AtCXE20 in Arabidopsis and maize resulted in phenotypes characteristic of strigolactone (SL)-deficient mutants, including increased branching and tillering, decreased plant height, delayed senescence, hyposensitivity to ethylene, and reduced flavonols. Maize silk growth was increased by AtCXE20 overexpression, and this phenotype was partially complemented by exogenous SL treatments. In drought conditions, the transgenic maize plants silked earlier than controls and had decreased anthesis-silking intervals. The purified recombinant AtCXE20 protein bound SL in vitro, as indicated by SL inhibiting AtCXE20 esterase activity and altering AtCXE20 intrinsic fluorescence. Homology modeling of the AtCXE20 three-dimensional (3D) protein structure revealed a large hydrophobic binding pocket capable of accommodating, but not hydrolyzing SLs. The AtCXE20 protein concentration in transgenic maize tissues was determined by mass spectrometry to be in the micromolar range, well-above known endogenous SL concentrations. These results best support a mechanism where ectopic expression of AtCXE20 with a strong promoter effectively lowers the concentration of free SL by sequestration. This study revealed an agriculturally important role for SL in maize silk growth and provided a new approach for altering SL levels in plants.

Re-visioning medicine.

Studies suggest that medical students and physicians have higher rates of anxiety, depression, and suicidal ideation than their peers in the general population. Some authors have suggested that medical culture perpetuates these problems by erecting "barriers to treatment," preventing students and physicians from getting the help they need. Here, the author begins a broader examination of the potential role of culture by examining the myths and symbols that form the basis for medical culture and the medical self-image. The author argues that a medical self-image based on a de-contextualized medical mythology, the Asclepius myth, results in a sense of professional identity that is unbalanced, dehumanized, and characterized by unattainable expectations. The outward expression of this medical self-image, the medical culture, is often a-relational, unhealthy, stressed, or even toxic. The author suggests some ways of re-modeling medical culture, including its rituals and symbols, and medical education in ways that incorporate what is currently kept in its shadow.

Rv0989c encodes a novel (E)-geranyl diphosphate synthase facilitating decaprenyl diphosphate biosynthesis in Mycobacterium tuberculosis.

Mycobacterium tuberculosis (Mtb) has a highly complex cell wall, which is required for both bacterial survival and infection. Cell wall biosynthesis is dependent on decaprenyl diphosphate as a glyco-carrier, which is hence an essential metabolite in this pathogen. Previous biochemical studies indicated (E)-geranyl diphosphate (GPP) is required for the synthesis of decaprenyl diphosphate. Here we demonstrate that Rv0989c encodes the "missing" GPP synthase, representing the first such enzyme to be characterized from bacteria, and which presumably is involved in decaprenyl diphosphate biosynthesis in Mtb. Our investigation also has revealed previously unrecognized substrate plasticity of the farnesyl diphosphate synthases from Mtb, resolving previous discrepancies between biochemical and genetic studies of cell wall biosynthesis.

Regional risk assessment as a part of the long-term receiving water study.

A regional-scale watershed assessment using the relative risk model has now been performed on each of the watersheds that are part of the Long-Term Receiving Waters Study (LTRWS) to generate patterns of risk at each study site. The watersheds assessed included the lower McKenzie and mid-Willamette rivers in Oregon, USA; Codorus Creek in Pennsylvania, USA; and the Leaf River in Mississippi, USA. In each case, the goal was to put the LTRWS into a watershed and regional context, including multiple sources, stressors, habitats, and assessment endpoints. In each instance, the relative risk model provided measures of relative risk and testable hypotheses about patterns within the watersheds. There were similarities among the 3 risk studies. First, land use within the watershed was the most important driver of risk in each instance, even compared with point sources. Second, the list of endpoints was similar for each risk assessment. Water quality was held as important, along with populations critical to recreation or commercial use. At each site, data from the LTRWS and other sources could be used to support the risk patterns predicted from the risk assessment process. However, the sampling design of the LTRWS prevented the confirmation of specific cause-effect relationships. A fundamental conclusion is that risk assessment, using an adaptation of the relative risk model, should be performed as an integral part of any watershed assessment and management effort. These initial watershed risk assessments have led to similar assessments across the world.