Medics in southern Queensland: Effects of sowing method, weed control and phosphorus application on plant population and biomass

Declining sown pasture productivity as a result of a tie-up in plant available soil nitrogen is an ongoing constraint to grazing production across the brigalow bioregion of central and southern Queensland. Research suggests that legume establishment offers the most cost effective long-term remediation strategy for improving pasture quality and yield. Within southern Queensland, medics (Medicago spp.) can provide valuable winter contributions to dietary protein and soil nitrogen, however establishment and yields are frequently poor and soil phosphorus often limiting. An experiment was established across two soil types (brigalow clay and poplar box red loam) 70 km north of Goondiwindi, Queensland to investigate the effects of sowing method, weed control and phosphorus fertiliser application on the establishment and yield of a mix of three medic cultivars (Medicago truncatula cv. Jester & cv .Caliph and Medicago orbicularis cv. Bindaroo Gold). On both soil types, plant population and biomass were significantly improved via direct drilling of seed as compared to broadcasting. On the loam, drilling increased average populations by between 519 and 1,900% above those recorded in broadcast treatments and improved biomass by between 144 and 315%. On the clay soil, drilling increased populations by between 339 and 983% above those measured in broadcast treatments. Clay soil drilling showed biomass improvements of between 124 and 1,368%. No significant biomass or legume population treatment effects were observed on the clay soil. No significant treatment effects were observed for yield on the loam soil. This study implies that medic establishment, plant populations and biomass can be greatly improved through the application of seed drilling

Determining the extent of declining pasture productivity with nitrogen fertiliser

Declining productivity of sown pastures due to a reduction in plant available soil nitrogen has typically reduced grass and beef production by 50% since initial land development within the Brigalow bioregion of southern and central Queensland. As this decline continues, it’s estimated it will cost the northern beef industry more than $17 billion over the next 30 years. To assist landholders determine the extent of declining pasture productivity on their own properties, and assess the magnitude of response if more nitrogen is made available, nitrogen fertiliser was applied to approximately 70 replicated and non-replicated sites across southern and central Queensland between 2012 and 2014. Nitrogen (N) fertiliser as Green Urea NV® (Incitec Fertilisers) was broadcast onto existing grass-pastures in the lead up to a forecast rainfall event in summer. A range of rates were applied, from 25 – 200 kg N/ha, and dry matter yields and protein levels were measured. At all sites the grass pasture responded to the added nitrogen, with the magnitude of response dependant on the amount of nitrogen applied. As the production from sown pastures continues to decline, options that improve nitrogen supply and address this decline will be required to improve beef production across the northern region

Determining the extent of declining pasture productivity with nitrogen fertiliser

Declining productivity of sown pastures due to a reduction in plant available soil nitrogen has typically reduced grass and beef production by 50% since initial land development within the Brigalow bioregion of southern and central Queensland. As this decline continues, it’s estimated it will cost the northern beef industry more than $17 billion over the next 30 years. To assist landholders determine the extent of declining pasture productivity on their own properties, and assess the magnitude of response if more nitrogen is made available, nitrogen fertiliser was applied to approximately 70 replicated and non-replicated sites across southern and central Queensland between 2012 and 2014. Nitrogen (N) fertiliser as Green Urea NV® (Incitec Fertilisers) was broadcast onto existing grass-pastures in the lead up to a forecast rainfall event in summer. A range of rates were applied, from 25 – 200 kg N/ha, and dry matter yields and protein levels were measured. At all sites the grass pasture responded to the added nitrogen, with the magnitude of response dependant on the amount of nitrogen applied. As the production from sown pastures continues to decline, options that improve nitrogen supply and address this decline will be required to improve beef production across the northern region

Photophysics of cage/guest assemblies : photoinduced electron transfer between a coordination cage containing osmium(II) luminophores, and electron-deficient bound guests in the central cavity

An octanuclear cubic Os4Zn4 coordination cage, containing Os(II) tris-diimine units at four of the eight vertices which are good photoelectron donors from their 3MLCT excited state, performs photoinduced electron transfer to electron-accepting organic guests which bind in the central cavity in water via the hydrophobic effect: the resulting charge-separated states have lifetimes of ca. 200 ps and have been characterized by transient absorption spectroscopy

Epidemiology and aetiology of community-acquired pneumonia in children: South African Thoracic Society guidelines (part 1)

Background. Pneumonia remains a major cause of morbidity and mortality among South African (SA) children. Improved immunisation regimens, strengthening of HIV programmes, better socioeconomic conditions and new preventive strategies have influenced the epidemiology of pneumonia. Furthermore, sensitive diagnostic tests and better sampling methods in young children improve aetiological diagnosis.Objectives. To summarise current information on childhood community-acquired pneumonia (CAP) epidemiology and aetiology in children as part of the revised South African Thoracic Society guidelines.Methods. The Paediatric Assembly of the South African Thoracic Society and the National Institute for Communicable Diseases expert subgroup on epidemiology and aetiology revised the existing SA guidelines.The subgroup reviewed the published evidence in their area; in the absence of evidence, expert opinion was accepted. Evidence was graded using the British Thoracic Society (BTS) grading system, and the relevant section underwent peer review.Results. Respiratory viruses, particularly respiratory syncytial virus, are the key pathogens associated with hospitalisation for radiologically confirmed pneumonia in HIV-uninfected children. Opportunistic organisms, including Pneumocystis jirovecii, are important pathogens in HIV-infected infants, while non-typable Haemophilus influenzae and Staphylococcus aureus are important in older HIV-infected children. Co-infections with bacteria or other respiratory viruses are common in hospitalised children. Mycobacterium tuberculosis is common in children hospitalised with CAP in SA.Conclusions. Numerous public health measures, including changes in immunisation schedules and expansion of HIV prevention and treatment programmes, have influenced the epidemiology and aetiology of CAP in SA children. These changes have necessitated a revision of the South African Paediatric CAP guidelines, further sections of which will be published as part of a CME series in SAMJ

Prevention of community-acquired pneumonia in children: South African Thoracic Society guidelines (part 4)

Background. More comprehensive immunisation regimens, strengthening of HIV prevention and management programmes and improved socioeconomic conditions have impacted on the epidemiology of paediatric community-acquired pneumonia (CAP) in South Africa (SA).Objectives. To summarise effective preventive strategies to reduce the burden of childhood CAP.Methods. An expert subgroup reviewed existing SA guidelines and new publications focusing on prevention. Published evidence on pneumonia prevention informed the revisions; in the absence of evidence, expert opinion was used. Evidence was graded using the British Thoracic Society (BTS) grading system.Recommendations. General measures for prevention include minimising exposure to tobacco smoke or air pollution, breastfeeding, optimising nutrition, optimising maternal health from pregnancy onwards, adequate antenatal care and improvement in socioeconomic and living conditions. Prevention of viral transmission, including SARS-CoV-2, can be achieved by hand hygiene, environmental decontamination, use of masks and isolation of infected people. Specific preventive measures include vaccines as contained in the Expanded Programme on Immunisation schedule, isoniazid prophylaxis for tuberculosis, co-trimoxazole prophylaxis for HIV-infected infants and children who are immunosuppressed, and timely diagnosis of HIV, as well as antiretroviral therapy (ART) initiation. HIV-infected children treated with ART from early infancy, and HIV-exposed children, have similar immunogenicity and immune responses to most childhood vaccines as HIV-unexposed infants.Validation. These recommendations are based on available published evidence supplemented by the consensus opinion of SA paediatric experts, and are consistent with those in published international guidelines

Diagnosis of community-acquired pneumonia in children: South African Thoracic Society guidelines (part 2)

Background. Accurate diagnosis and attribution of the aetiology of pneumonia are important for measuring the burden of disease, implementing appropriate treatment strategies and developing more effective interventions.Objectives. To produce revised guidelines for the diagnosis of pneumonia in South African (SA) children, encompassing clinical, radiological and aetiological methods.Methods. An expert group was established to review diagnostic evidence and make recommendations for a revised SA guideline. Published evidence was reviewed and graded using the British Thoracic Society grading system.Results. Diagnosis of pneumonia should be considered in a child with acute cough, fast breathing or difficulty breathing. Revised World Health Organization guidelines classify such children into: (i) severe pneumonia; (ii) pneumonia (tachypoea or lower chest indrawing); or (iii) no pneumonia. Malnourished or immunocompromised children with lower chest indrawing should be managed as cases of severe pneumonia. Pulse oximetry should be done, with hospital referral for oxygen saturation <92%. A chest X-ray is indicated in severe pneumonia or when tuberculosis (TB) is suspected. Microbiological investigations are recommended in hospitalised patients or in outbreak settings. Improved aetiological methods show the importance of co-infections. Blood cultures have a low sensitivity (<5%), for diagnosing bacterial pneumonia. Highly sensitive, multiplex tests on upper respiratory samples or sputum detect multiple potential pathogens in most children. However, even in symptomatic children, it may be impossible to distinguish colonising from causative organisms, unless identification of the organism is strongly associated with attribution to causality, e.g. respiratory syncytial virus, Mycobacterium tuberculosis, Bordetella pertussis, influenza, para-influenza or severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Investigations for TB should be considered in children with severe pneumonia who have been hospitalised, in a case of a known TB contact, if the tuberculin skin test is positive, if a child is malnourished or has lost weight, and in children living with HIV. Induced sputum may provide a higher yield than upper respiratory sampling for B. pertussis, M. tuberculosis and Pneumocystis jirovecii. Conclusions. Advances in clinical, radiological and aetiological methods have improved the diagnosis of childhood pneumonia

One guest or two? A crystallographic and solution study of guest binding in a cubic coordination cage

A crystallographic investigation of a series of host/guest complexes in which small‐molecule organic guests occupy the central cavity of an approximately cubic M 8 L 12 coordination cage has revealed some unexpected behaviour. Whilst some guests form 1:1 H•G complexes as we have seen before, an extensive family of bicyclic guests – including some substituted coumarins and various saturated analogues – form 1:2 H•G 2 complexes in the solid state, despite the fact that solution titrations are consistent with 1:1 complex formation, and the combined volume of the pair of guests significantly exceeds the Rebek 55±9% packing for optimal guest binding, with packing coefficients of up to 87%. Re‐examination of solution titration data for guest binding in two cases showed that, although conventional fluorescence titrations are consistent with 1:1 binding model, alternative forms of analysis – Job plot and an NMR titration – at higher concentrations do provide evidence for 1:2 H•G 2 complex formation. The observation of guests binding in pairs in some cases opens up new possibilities for altered reactivity of bound guests, and also highlights the recently‐articulated difficulties associated with determining stoichiometry of supramolecular complexes in solution

Integrated Modelling Frameworks for Environmental Assessment and Decision Support

As argued in Chapter 1, modern management of environmental resources defines problems from a holistic and integrated perspective, thereby imposing strong requirements on Environmental Decision Support Systems (EDSSs) and Integrated Assessment Tools (IATs). These systems and tools tend to be increasingly complex in terms of software architecture and computational power in order to cope with the type of problems they must solve. For instance, the discipline of Integrated Assessment (IA) needs tools that arc able to span a wide range of disciplines, from socio-economics to ecology to hydrology. Such tools must support a wide range of methodologies and techniques like agent-based modeling, Bayesian decision networks, optimization, multicriteria analyses and visualization tools, to name a few

Folding-competent and folding-defective forms of Ricin A chain have different fates following retrotranslocation from the endoplasmic reticulum

We report that a toxic polypeptide retaining the potential to refold upon dislocation from the endoplasmic reticulum (ER) to the cytosol (ricin A chain; RTA) and a misfolded version that cannot (termed RTAΔ), follow ER-associated degradation (ERAD) pathways in Saccharomyces cerevisiae that substantially diverge in the cytosol. Both polypeptides are dislocated in a step mediated by the transmembrane Hrd1p ubiquitin ligase complex and subsequently degraded. Canonical polyubiquitylation is not a prerequisite for this interaction because a catalytically inactive Hrd1p E3 ubiquitin ligase retains the ability to retrotranslocate RTA, and variants lacking one or both endogenous lysyl residues also require the Hrd1p complex. In the case of native RTA, we established that dislocation also depends on other components of the classical ERAD-L pathway as well as an ongoing ER–Golgi transport. However, the dislocation pathways deviate strikingly upon entry into the cytosol. Here, the CDC48 complex is required only for RTAΔ, although the involvement of individual ATPases (Rpt proteins) in the 19S regulatory particle (RP) of the proteasome, and the 20S catalytic chamber itself, is very different for the two RTA variants. We conclude that cytosolic ERAD components, particularly the proteasome RP, can discriminate between structural features of the same substrate