Soil acidity and liming in Natal.

Thesis (Ph.D.)-University of Natal, Pietermaritzburg, 1970.1. Effects of Aluminium Toxicity and Phosphorus Fixation on Crop Growth on Oxisols in Natal Simple, routine methods for estimating exchangeable Al and P fixing capacity of acid soils are described. A glass-house study on eight Oxisols revealed marked growth response of 'trudan' (Sorghum sudanense) to amelioration by lime, gypsum and Ca silicate which is ascribed to elimination of A1 toxicity rather than to improved P availability. Growth response to amelia rants took place up to the point of elimination of exchangeable Al after which a significant reduction in yield occurred. P fixation is shown to be a major fertility limitation in the soils studied. Since no apparent relationship between P fixing capacity and exchangeable A1 existed and since lime did not decrease P fixation despite its ability to eliminate soluble A1, it is concluded that P fixation is an adsorption reaction rather than a precipitation reaction. Although the soils studied are all capable of fixing large quantities of P considerable variation exists between them. Fertilizer recommendations based only on an estimate of the available P in the soil per se could thus be in serious error. 2. Lime Requirements of Natal Oxisols based on Exchangeable Aluminium The exchangeable Al status of eight Natal Oxisols is a suitable criterion for the measurement of lime requirement defined as the amount of lime necessary for maximum crop production. The principal function of lime in these soils is to eliminate A1 toxicity; it has little or no effect on P availability. A "critical value" for exchangeable A1 below which 'trudan' did not respond to lime application was found. On the average the amount of lime necessary for maximum growth and exchangeable Al control was approximately one sixth the amount required to raise the soil pH to 6.5. 3. Cation Exchange Capacity and Exchangeable Aluminium in Natal Oxisols Positive charges in acid soils reduce CEC at low electrolyte concentration probably by double layer interaction. The resultant net CEC (determined by washing soil free of salt with water) is the effective CEC under field conditions and the difference between net CEC and exchangeable bases is accordingly a convenient measure of exchangeable A1. A reaction scheme is proposed which relates the large pool of non-exchangeable Al (extractable with N NH[4]0Ac-pH4) in these soils to the relatively small amounts of exchangeable AI; this reaction scheme is governed primarily by net CEC and exchangeable bases rather than by pH. 4. Amelioration of Subsoil Acidity in Natal Oxisols, The large pH dependent CEC in Natal Oxisols effectively limits the downward movement of lime. Although heavy fertilisation, particularly with acid forming nitrogenous fertilizers increases the rate of movement, relatively small amounts of Ca salts having little ability to neutralise subsoil exchangeable Al could be leached from limed topsoil. In contrast, bases equivalent to 80% of that applied leached rapidly from gypsum treated topsoil. Although gypsum did not eliminate subsoil exchangeable A1, it was considerably more efficient than lime in this respect. However, gypsum caused severe loss of exchangeable Mg which could have serious nutritional consequences if not corrected

Influenza-associated mortality in hospital care: a retrospective cohort study of risk factors and impact of oseltamivir in an English teaching hospital, 2016 to 2017.

BackgroundEvidence of an oseltamivir treatment effect on influenza A(H3N2) virus infections in hospitalised patients is incomplete.AimsThis cohort study aimed to evaluate risk factors for death among PCR-confirmed hospitalised cases of seasonal influenza A(H3N2) of all ages and the impact of oseltamivir.MethodsParticipants included all 332 PCR-confirmed influenza A(H3N2) cases diagnosed between 30 August 2016 and 17 March 2017 in an English university teaching Hospital. Oseltamivir treatment effect on odds of inpatient death was assessed by backward stepwise multivariable logistic regression analysis.ResultsThe odds of death were reduced by two thirds (odds ratio (OR): 0.32; 95% confidence interval (CI): 0.11-0.93), in inpatients treated with a standard course of oseltamivir 75 mg two times daily for 5 days - compared with those untreated with oseltamivir, after adjustment for age, sex, current excess alcohol intake, receipt of 2016/17 seasonal influenza vaccine, serum haemoglobin and hospital vs community attribution of acquisition of influenza.ConclusionsOseltamivir treatment given according to National Institutes of Clinical Excellence (NICE); United States Centres for Disease Control and Prevention (CDC); Infectious Diseases Society of America (IDSA) and World Health Organization (WHO) guidelines was shown to be effective in reducing the odds of mortality in inpatients with PCR-confirmed seasonal influenza A(H3N2) after adjustment in a busy routine English hospital setting. Our results highlight the importance of hospitals complying with relevant guidelines for prompt seasonal influenza PCR testing and ensuring standard oseltamivir treatment to all PCR-confirmed cases of seasonal influenza

Carbon-sensitive pedotransfer functions for plant available water

Currently accepted pedotransfer functions show negligible effect of management-induced changes to soil organic carbon (SOC) on plant available water holding capacity (θAWHC), while some studies show the ability to substantially increase θAWHC through management. The Soil Health Institute\u27s North America Project to Evaluate Soil Health Measurements measured water content at field capacity using intact soil cores across 124 long-term research sites that contained increases in SOC as a result of management treatments such as reduced tillage and cover cropping. Pedotransfer functions were created for volumetric water content at field capacity (θFC) and permanent wilting point (θPWP). New pedotransfer functions had predictions of θAWHC that were similarly accurate compared with Saxton and Rawls when tested on samples from the National Soil Characterization database. Further, the new pedotransfer functions showed substantial effects of soil calcareousness and SOC on θAWHC. For an increase in SOC of 10 g kg–1 (1%) in noncalcareous soils, an average increase in θAWHC of 3.0 mm 100 mm–1 soil (0.03 m3 m–3) on average across all soil texture classes was found. This SOC related increase in θAWHC is about double previous estimates. Calcareous soils had an increase in θAWHC of 1.2 mm 100 mm–1 soil associated with a 10 g kg–1 increase in SOC, across all soil texture classes. New equations can aid in quantifying benefits of soil management practices that increase SOC and can be used to model the effect of changes in management on drought resilience

Linking soil microbial community structure to potential carbon mineralization: A continental scale assessment of reduced tillage

Potential carbon mineralization (Cmin) is a commonly used indicator of soil health, with greater Cmin values interpreted as healthier soil. While Cmin values are typically greater in agricultural soils managed with minimal physical disturbance, the mechanisms driving the increases remain poorly understood. This study assessed bacterial and archaeal community structure and potential microbial drivers of Cmin in soils maintained under various degrees of physical disturbance. Potential carbon mineralization, 16S rRNA sequences, and soil characterization data were collected as part of the North American Project to Evaluate Soil Health Measurements (NAPESHM). Results showed that type of cropping system, intensity of physical disturbance, and soil pH influenced microbial sensitivity to physical disturbance. Furthermore, 28% of amplicon sequence variants (ASVs), which were important in modeling Cmin, were enriched under soils managed with minimal physical disturbance. Sequences identified as enriched under minimal disturbance and important for modeling Cmin, were linked to organisms which could produce extracellular polymeric substances and contained metabolic strategies suited for tolerating environmental stressors. Understanding how physical disturbance shapes microbial communities across climates and inherent soil properties and drives changes in Cmin provides the context necessary to evaluate management impacts on standardized measures of soil microbial activity

Influenza-associated mortality in hospital care: a retrospective cohort study of risk factors and impact of oseltamivir in an English teaching hospital, 2016 to 2017.

BackgroundEvidence of an oseltamivir treatment effect on influenza A(H3N2) virus infections in hospitalised patients is incomplete.AimsThis cohort study aimed to evaluate risk factors for death among PCR-confirmed hospitalised cases of seasonal influenza A(H3N2) of all ages and the impact of oseltamivir.MethodsParticipants included all 332 PCR-confirmed influenza A(H3N2) cases diagnosed between 30 August 2016 and 17 March 2017 in an English university teaching Hospital. Oseltamivir treatment effect on odds of inpatient death was assessed by backward stepwise multivariable logistic regression analysis.ResultsThe odds of death were reduced by two thirds (odds ratio (OR): 0.32; 95% confidence interval (CI): 0.11-0.93), in inpatients treated with a standard course of oseltamivir 75 mg two times daily for 5 days - compared with those untreated with oseltamivir, after adjustment for age, sex, current excess alcohol intake, receipt of 2016/17 seasonal influenza vaccine, serum haemoglobin and hospital vs community attribution of acquisition of influenza.ConclusionsOseltamivir treatment given according to National Institutes of Clinical Excellence (NICE); United States Centres for Disease Control and Prevention (CDC); Infectious Diseases Society of America (IDSA) and World Health Organization (WHO) guidelines was shown to be effective in reducing the odds of mortality in inpatients with PCR-confirmed seasonal influenza A(H3N2) after adjustment in a busy routine English hospital setting. Our results highlight the importance of hospitals complying with relevant guidelines for prompt seasonal influenza PCR testing and ensuring standard oseltamivir treatment to all PCR-confirmed cases of seasonal influenza

EU/U.S. Roadmap to measuring the results of investments in science: the Bellagio Statement: a report following the “EU/US Science of Science Policy” Rockefeller Foundation Bellagio Center Workshop, 27 June – 30 June 2011

Public and private investments in science and technology (S&T) have significantly increased over the past decades in Europe and the United States. The results have been transformative – ushering in the telecommunications and internet revolutions; providing better access to food, water, and shelter; improving health care; combating environmental degradation and climate change; and helping to inform policies to promote social and economic security. It is essential that these investments continue to create value for the public. Indeed, national governments are increasingly asking complex and probing questions regarding the effects of their investments; they want transparency and accountability for the spending of taxpayers’ money; and they want their decisions regarding investments in science to be informed by data-driven analyses. Now more than ever before, the science community must explain and justify the spending on publicly-funded research. While it is clear that research pays off in general, there is great skepticism about both the marginal value of spending, and the chosen investment targets. There is a clear requirement to ensure greater effectiveness and efficiency in the use of public research funding; reduce the reporting burden on scientists; and to exploit the enormous analytical power generated by advances in information technology. Experts from the European Union and the United States met at the Rockefeller Foundation in Bellagio, Italy, to examine these issues. The task at hand should not be underestimated. Although the potential return from this work is enormous, the scale of the challenge of developing these new ideas into workable solutions for policy makers is also very significant. Despite the major strides already made in the U.S. through the National Science Foundation’s Science of Science and Innovation Policy (SciSIP) program and the interagency STAR METRICS program, a shared approach with other nations would certainly both accelerate progress and implementation. The purpose of the Bellagio conference was to explore the formation of a mutually beneficial multi-national collaboration in documenting the results of investments in science. The group believes science today is a global activity. Scientists and engineers collaborate across borders, move across borders and the benefits of their research know no borders. Expansion beyond current measurement systems could both broaden and deepen participation in science