Integration of organic poultry in whole farm systems: manure nutrient budgets

This report was presented at the UK Organic Research 2002 Conference. The aim of this project was to examine how rotations incorporating organic poultry use the cycling of nutrients between soil, crops and birds. Poultry studies have measured nutrient values of manure in slow growing meat birds at about day 81 when fed typical broiler rations versus “Label Rouge” rations. Nutrient (N, P, K) balances were constructed to assess the viability of integrating poultry production within a theoretical organic rotation. The readilyplant- available nitrogen in manure from Ross 308 birds fed either presumed non-limiting rations or Label Rouge rations was within the range reported for intensive broilers. For ISA 657 birds, the manure readily-plant-available nitrogen was similar to the mean value reported for broilers, when fed presumed non limiting rations, but towards the lower range when fed Label Rouge rations. As breed growth and feed intakes differ it is suggested that to optimise the utilisation of nutrients, the nutrient content of table bird manures should be checked prior to land application. The nutrient budgets were similar for N and P regardless of the length of rotation or form of poultry production. On average, there was a surplus of 85 kg/ha N over all the scenarios. There tended to be a deficit of K in all scenarios (average: 10 kg/ha)

Relation between renal calcium content and renal impairment in 246 human renal biopsies

Relation between renal calcium content and renal impairment in 246 human renal biopsies. Tissue calcium content from 246 diagnostic human renal biopsies was measured to assess whether elevated tissue calcium concentration could be demonstrated to exist early during the course of human renal disease or was only a manifestation of advanced renal impairment. Renal calcium content correlated significantly with serum creatinine (r = +0.23, P < 0.001, N = 246); serum phosphate (r = +0.27, P < 0.001, N = 169) but not with serum calcium (r = -0.10, P > 0.1, N = 193). Fivefold greater calcium content was measured in biopsied patients with normal renal function than in normal postmortem renal tissue (35.7 ± 5.2 vs. 7.6 ± 0.7 mgCa/100 g wet renal tissue, P < 0.001). Those biopsied patients with significant functional impairment (SCr > 1.5 mg/dl) had a higher mean level of serum phosphorus and serum [Ca] × [P] product than patients with normal renal function (5.19 ± 0.22 vs. 3.92 ± 0.11mg P/dl and 44.8 ± 1.8 vs. 35.7 ± 1.2 mg2/dl2, respectively), and slightly higher renal calcium content (85.3 ± 32.2 vs. 35.7 ± 5.2 Ca/100 g wet renal tissue, P = 0.06), which correlated with histologic calcium deposition (r = +0.52, P < 0.02, N = 20). These findings are consistent with the hypothesis that renal calcium deposition begins early in the course of a variety of renal diseases and hence may play a secondary pathogenetic role that accelerates progression to chronic renal failure. Severity of renal calcium deposition is equally closely related to hyperphosphatemia and to the level of renal impairment

Relationship between sociodemographic factors and specialty destination of UK trainee doctors:a national cohort study

We are grateful to UKMED for releasing the data for this project. We also are grateful to the following for their support of the application to UKMED for this and other research projects: Dr Sally Curtis (University of Southampton, UK), Dr Sandra Nicholson (Barts and The London School of Medicine and Dentistry, UK). We thank Daniel Smith and Andy Knapton of the General Medical Council of the UK for their support for the application and throughout the project, particularly regarding data linkage and troubleshooting.Peer reviewedPublisher PD

Regulation of plasma aldosterone concentration in anephric man and renal transplant recipients

Regulation of plasma aldosterone concentration in anephric man and renal transplant recipients. Regulatory factors controlling plasma aldosterone in the anephric state were further examined in bilaterally nephrectomized patients and renal transplant recipients. The effect of supine and upright posture on the concentration of plasma aldosterone, and the possible role of potassium in these responses in the anephric patients, was studied on the first and either the third or fourth day post-dialysis (anephric patients) and during periods of high and low sodium intake (renal transplant recipients). As previously reported, a significant correlation between plasma aldosterone and serum potassium concentration (r = 0.871, P<0.001) could be demonstrated in anephric patients. In addition, the present studies demonstrate that in a single anephric individual, changes in serum potassium concentration are associated with concordant alterations in plasma aldosterone concentration (r value for Δ plasma aldosterone concentration in anephric patients on the third or fourth day post-dialysis was 0.911, P<0.005). Changes in posture from supine to upright produced no change in the concentration of plasma aldosterone in the anephric patients that could not be attributed to variations in the serum potassium concentration. In contrast, the plasma aldosterone concentration in renal transplant recipients increased significantly after two hours of ambulation during both high and low sodium intake, and was correlated with plasma renin activity (PRA). These studies demonstrate that plasma aldosterone, in the absence of the kidneys, is unresponsive to postural variation under conditions in which significant changes in plasma aldosterone concentrations are observed in renal transplant recipients. Thus, additional evidence indicating that changes in potassium rather than volume-related stimuli are the primary regulator of plasma aldosterone in anephric patients is provided.Régulation de la concentration plasmatique d'aldostérone au cours de l'anéphrie et après la transplantation rénale. Les facteurs régulateurs contrôlant la secrétion d'aldostérone au cours de l'anéphrie ont été étudiés chez des malades ayant subi une néphrectomie bilatérale et chez des transplantés. L'effet de la position couchée ou debout sur la concentration plasmatique d'aldostérone et le rôle possible du potassium dans ces réponses chez le malade anéphrique ont été étudiés le premier et le troisième ou quatrième jour après dialyse (malades anéphriques) et durant des périodes de régime riche puis pauvre en sodium (receveurs de reins transplantés). Ainsi que nous l'avons antérieurement rapporté il existe une corrélation significative entre les concentrations plasmatiques d'aldostérone et de potassium (r = 0,871; P<0,001) chez le malade anéphrique. De surcroît, l'étude actuelle démontre que chez un même sujet anéphrique les modifications de la concentration du potassium sont associées à des modifications concordantes de la concentration plasmatique d'aldostérone (le r de la corrélation Δ du potassium plasmatique avec Δ d'aldostérone plasmatique chez le sujet anéphrique le troisième ou le quatrième jour post dialyse est égal à 0,911; P<0,005). Le passage de la position couchée à la position debout ne produit pas de modification de l'aldostérone plasmatique, chez les sujets anéphriques, qui ne pourraient être attribués aux modifications du potassium plasmatique. Al'opposé, l'aldostérone plasmatique chez les transplantés augmente significativement après 2 heures d'ambulation, que le régime soit riche ou pauvre en sel, et elle est correlée avec l'activité rénine plasmatique. Ces résultats démontrent que la secrétion d'aldostérone, en l'absence de reins, ne répond pas auxh modifications posturales dans des conditions où des modifications significatives de la concentration plasmatique d'aldostérone sont observées chez les sujets transplantés. Ainsi des arguments supplémentaires indiquent que les modifications de potassium, plus que des stimuli volémiques, sont le facteur primaire de la régulation de la secrétion d'aldostérone chez l'anéphrique

Doxycycline pharmacokinetics in the absence of renal function

Doxycycline pharmacokinetics in the absence of renal function. Doxycycline is a new tetracycline that is now in widespread clinical use. It differs from the other tetracycline drugs in many important respects including small daily dosage schedules, essentially complete upper gastrointestinal absorption and excretory characteristics that are independent of renal function. Our studies demonstrate that in anephric patients and patients with varying degrees of renal function the plasma t½ of biologically active doxycycline is not significantly extended and that in such a clinical situation the usual therapeutic regimen of the drug is necessary. Clearance rate of the compound from the systemic circulation by hemodialysis is only 10ml/min or less. In addition, our investigations identify the importance of the nonhepatic gastrointestinal pathway of elimination of doxycycline from the systemic circulation. Doxycycline therefore appears to be unique among the tetracyclines in that it may be utilized as a drug of choice for the therapy of systemic infections when a tetracycline compound is indicated in the clinical setting of impaired renal function.Pharmacocinétique de la doxycycline en l'absence de fonction rénale. La doxycycline est une nouvelle tétracycline dont l'usage clinique est maintenant largement répandu. Elle diffère des autres tétracyclines à plusieurs égards importants parmi lesquels la faible posologie quotidienne, l'absorption totale dans la partie haute du tractus digestif et des modalités d'excrétion indépendantes de la fonction rénale. Notre travail démontre que chez les sujets anéphriques et les malades atteints d'insuffisance rénale de sévérité variable la demie vie de la doxycycline biologiquement active n'est pas significativement allongée et que dans ces situations cliniques les modalités thérapeutiques habituelles sont nécessaires. La clearance du composé observée au cours de l'hémodialyse est égale ou inférieure à 10 ml/min. De surcroît nos travaux identifient l'importance de la voie d'élimination hépatique non intestinale de la doxycycline. La doxycycline apparaît donc être unique parmi les tétracyclines en ce sens qu'elle peut être utilisée comme une drogue de choix pour le traitment des infections systémiques quand une tétracycline est indiquée et qu'il existe une altération de la fonction rénale

Characteristics of patients who die of necrotizing enterocolitis

Objective:Necrotizing enterocolitis (NEC) is associated with high morbidity and mortality among infants admitted for intensive care. The factors associated with mortality and catastrophic presentation remain poorly understood. Our objective was to describe the factors associated with mortality in infants with NEC and to quantify the degree to which catastrophic presentation contributes to mortality in infants with NEC. Catastrophic NEC was defined before data analysis as NEC that led to death within 7 days of diagnosis.Study Design:We performed a retrospective review of the Pediatrix's Clinical Data Warehouse (1997 to 2009, n=560,227) to compare the demographic, therapeutic and outcome characteristics of infants who survived NEC vs those who died. Associations were tested by bivariate and multivariate analysis.Result:We compared the 5594 infants diagnosed with NEC and who were discharged home with 1505 infants diagnosed with NEC who died. In multivariate analysis, the factors associated with death (P<0.01 in analysis) were lower estimated gestational age, lower birth weight, treatment with assisted ventilation on the day of diagnosis of NEC, treatment with vasopressors at the time of diagnosis, and Black race. Patients who received only ampicillin and gentamicin on the day of diagnosis were less likely to die. Two-thirds of NEC deaths occurred quickly (<7 days from diagnosis), with a median time of death of one day from time of diagnosis. Infants who died within 7 days of diagnosis had a higher birth weight, more often were on vasopressors and high frequency ventilation at the time of diagnosis compared with patients who died at 7 or more days. Although mortality decreased with increasing gestational age, the proportion of deaths that occurred within 7 days was relatively consistent (65 to 75% of the patients who died) across all gestational ages.Conclusion:Mortality among infants who have NEC remains high and infants who die of NEC commonly (66%) die quickly. Most of the factors associated with mortality are related to immaturity, low birth weight and severity of illness

An Upper Limit on the Albedo of HD 209458b: Direct Imaging Photometry with the MOST Satellite

We present space-based photometry of the transiting exoplanetary system HD 209458 obtained with the MOST (Microvariablity and Oscillations of STars) satellite, spanning 14 days and covering 4 transits and 4 secondary eclipses. The HD 209458 photometry was obtained in MOST's lower-precision Direct Imaging mode, which is used for targets in the brightness range $6.5 < V < 13$. We describe the photometric reduction techniques for this mode of observing, in particular the corrections for stray Earthshine. We do not detect the secondary eclipse in the MOST data, to a limit in depth of 0.053 mmag (1 \sigma). We set a 1 \sigma upper limit on the planet-star flux ratio of 4.88 x 10^-5 corresponding to a geometric albedo upper limit in the MOST bandpass (400 to 700 nm) of 0.25. The corresponding numbers at the 3 \sigma level are 1.34 x 10^-4 and 0.68 respectively. HD 209458b is half as bright as Jupiter in the MOST bandpass. This low geometric albedo value is an important constraint for theoretical models of the HD209458b atmosphere, in particular ruling out the presence of reflective clouds. A second MOST campaign on HD 209458 is expected to be sensitive to an exoplanet albedo as low as 0.13 (1 sigma), if the star does not become more intrinsically variable in the meantime.Comment: 29 pages, 9 figures. Accepted for publication in the Astrophysical Journal (July 2006, v645n1