Peatland vascular plant functional types affect dissolved organic matter chemistry

Aims

The readily available global rock phosphate (P) reserves may be depleted within the next 50–130 years warranting careful use of this finite resource. We develop a model that allows us to assess a range of P fertiliser and soil management strategies for Barley in order to find which one maximises plant P uptake under certain climate conditions.

Methods

Our model describes the development of the P and water profiles within the soil. Current cultivation techniques such as ploughing and reduced till gradient are simulated along with fertiliser options to feed the top soil or the soil right below the seed.

Results

Our model was able to fit data from two barley field trials, achieving a good fit at early growth stages but a poor fit at late growth stages, where the model underestimated plant P uptake. A well-mixed soil (inverted and 25 cm ploughing) is important for optimal plant P uptake and provides the best environment for the root system.

Conclusions

The model is sensitive to the initial state of P and its distribution within the soil profile; experimental parameters which are sparsely measured. The combination of modelling and experimental data provides useful agricultural predictions for site specific locations.

     

Waist Circumference as a Screening Tool for Cardiovascular Risk Factors: Evaluation of Receiver Operating Characteristics (ROC)

To evaluate the receiver operating characteristics (ROC) to determine the cutoffs of waist circumference as a potential population directed screening tool for hypercholesterolaemia (≥6.5 mmol/L), low high density lipoprotein cholesterol (<0.9 mmol/L), and hypertension (treated and/or systolic ≥160 and/or diastolic blood pressure ≥95 mmHg), in 2183 men and 2698 women aged 20 to 59 years selected at random from Dutch civil registries. Main outcome measures: Height, weight, body mass index (BMI), waist circumference, total plasma cholesterol and high density lipoprotein cholesterol concentrations, and blood pressure. Results: ROC curves showed that sensitivity equalled specificity at waist circumferences between 93–95 cm in men and 81–84 cm in women for identifying individual risk factors, and 92 cm in men and 81 cm in women for identifying those with at least one risk factor. Sensitivity and specificity were equal at levels between 61% to 69% for identifying individual risk factors, with positive predictions (56.8% in men and 37.8% in women) within 2% of those using previously defined ‘Action Level 1’ of waist circumference 94 cm in men and 80 cm in women (58.8% in men and 37.4% in women). Risk prediction by anthropometric methods was relatively low: ROC areas for identifying each risk factor by waist varied from 55% to 60%, and reached about 65% for identifying at least one risk factor. Height accounted for less than 03% of variance in waist circumference. Using BMI at 25 kg/m² gave similar prediction to waist, but its combination with waist did not improve predictive values. Conclusions: Measurement of waist circumference ‘Action Level 1’ at 94 cm (37 inches) in men and 80 cm (32 inches) in women could be adopted as a simpler valid alternative to BMI for health promotion, to alert those at risk of cardiovascular disease, and as a guide to risk avoidance by self-weight management     

Fertilization effects with P on accumulated leaf area duration,biomass and yield of three cultivars of maize in Toluca,Mexico

The effect of six phosphorus levels (0, 40, 80, 120, 160 and 200 kg/ha) on the duration of cumulative leaf area, biomass and agronomic yield was determined in the maize cultivars: Amarillo Almoloya, Cacahuacintle and Condor in 2010 and 2011. Such cultivars were sown in the Cerrillo Piedras Blancas Mexico. A completely randomized complete block design with factorial arrangement was utilized. High phosphorus levels (120, 160 and 200 kg/ha) positively affected the duration of cumulative leaf area; greatest values were obtained in Cacahuacintle. A greater duration of accumulated leaf area contributes to determine high values of biomass accumulation and grain yield in this cultivar. Leaf area duration appeared to be a useful tool for evaluating different genotypes in a given environment.     

Dexamethasone induces gelsolin synthesis and altered morphology in L929 cells

When L929 cells are exposed to 5 μg/ml dexamethasone, synthesis of a 90,000 M(r) polypeptide is induced within 12 h. Flattening of the cells begins at about this time and progresses to become quite prominent after 48 h of exposure. Two-dimensional PAGE and partial proteolytic fingerprints identify the 90,000 M(r) polypeptide as gelsolin, a Ca(++)-dependent inhibitor of actin polymerization. Thus, this system provides evidence that gelsolin may have a role in regulating cell shape in response to physiological agents such as glucocorticoids.     

The canine isolate Lactobacillus acidophilus LAB20 adheres to intestinal epithelium and attenuates LPS-induced IL-8 secretion of enterocytes in vitro

Background

For a good probiotic candidate, the abilities to adhere to intestinal epithelium and to fortify barrier function are considered to be crucial for colonization and functionality of the strain. The strain Lactobacillus acidophilus LAB20 was isolated from the jejunum of a healthy dog, where it was found to be the most pre-dominant lactobacilli. In this study, the adhesion ability of LAB20 to intestinal epithelial cell (IECs) lines, IECs isolated from canine intestinal biopsies, and to canine, porcine and human intestinal mucus was investigated. Further, we studied the ability of LAB20 to fortify the epithelial cell monolayer and to reduce LPS-induced interleukin (IL-8) release from enterocytes.

Results

We found that LAB20 presented higher adhesion to canine colonic mucus as compared to mucus isolated from porcine colon. LAB20 showed adhesion to HT-29 and Caco-2 cell lines, and importantly also to canine IECs isolated from canine intestinal biopsies. In addition, LAB20 increased the transepithelial electrical resistance (TER) of enterocyte monolayers and thus strengthened the intestinal barrier function. The strain showed also anti-inflammatory capacity in being able to attenuate the LPS-induced IL-8 production of HT-29 cells.

Conclusion

In conclusion, canine indigenous strain LAB20 is a potential probiotic candidate for dogs adhering to the host epithelium and showing intestinal barrier fortifying and anti-inflammatory effects.

Electronic supplementary material

The online version of this article (doi:10.1186/s12866-014-0337-9) contains supplementary material, which is available to authorized users.     

Potential for epidemic take-off from the primary outbreak farm via livestock movements

Background

We consider the potential for infection to spread in a farm population from the primary outbreak farm via livestock movements prior to disease detection. We analyse how this depends on the time of the year infection occurs, the species transmitting, the length of infectious period on the primary outbreak farm, location of the primary outbreak, and whether a livestock market becomes involved. We consider short infectious periods of 1 week, 2 weeks and 4 weeks, characteristic of acute contagious livestock diseases. The analysis is based on farms in Scotland from 1 January 2003 to 31 July 2007.

Results

The proportion of primary outbreaks from which an acute contagious disease would spread via movement of livestock is generally low, but exhibits distinct annual cyclicity with peaks in May and August. The distance that livestock are moved varies similarly: at the time of the year when the potential for spread via movements is highest, the geographical spread via movements is largest. The seasonal patterns for cattle differ from those for sheep whilst there is no obvious seasonality for pigs. When spread via movements does occur, there is a high risk of infection reaching a livestock market; infection of markets can amplify disease spread. The proportion of primary outbreaks that would spread infection via livestock movements varies significantly between geographical regions.

Conclusions

In this paper we introduce a set-up for analysis of movement data that allows for a generalized assessment of the risk associated with infection spreading from a primary outbreak farm via livestock movements, applying this to Scotland, we assess how this risk depends upon the time of the year, species transmitting, location of the farm and other factors.     

Predicting low testosterone in aging men: a systematic review

Background:Physicians diagnose and treat suspected hypogonadism in older men by extrapolating from the defined clinical entity of hypogonadism found in younger men. We conducted a systematic review to estimate the accuracy of clinical symptoms and signs for predicting low testosterone among aging men.Methods:We searched the MEDLINE and Embase databases (January 1966 to July 2014) for studies that compared clinical features with a measurement of serum testosterone in men. Three of the authors independently reviewed articles for inclusion, assessed quality and extracted data.Results:Among 6053 articles identified, 40 met the inclusion criteria. The prevalence of low testosterone ranged between 2% and 77%. Threshold testosterone levels used for reference standards also varied substantially. The summary likelihood ratio associated with decreased libido was 1.6 (95% confidence interval [CI] 1.3–1.9), and the likelihood ratio for absence of this finding was 0.72 (95% CI 0.58–0.85). The likelihood ratio associated with the presence of erectile dysfunction was 1.5 (95% CI 1.3–1.8) and with absence of erectile dysfunction was 0.83 (95% CI 0.76–0.91). Of the multiple-item instruments, the ANDROTEST showed both the most favourable positive likelihood ratio (range 1.9–2.2) and the most favourable negative likelihood ratio (range 0.37–0.49).Interpretation:We found weak correlation between signs, symptoms and testosterone levels, uncertainty about what threshold testosterone levels should be considered low for aging men and wide variation in estimated prevalence of the condition. It is therefore difficult to extrapolate the method of diagnosing pathologic hypogonadism in younger men to clinical decisions regarding age-related testosterone decline in aging men.Male hypogonadism is defined as the presence of low serum testosterone and spermatozoa levels, accompanied by clinical signs and symptoms.¹ The Endocrine Society divides the symptoms and signs of androgen deficiency into 2 groups, based on expert consensus.¹ The first group, which is considered more specific, includes incomplete or delayed sexual development; eunuchoidism; reduced sexual desire (libido); erectile dysfunction; gynecomastia; decreased axillary, facial and pubic hair; small testes (i.e., volume < 5 mL); infertility: low-trauma fracture; low bone mineral density; and hot flushes.¹ The second group includes less specific signs and symptoms, such as decreased energy and motivation, depressed mood, poor concentration and memory, sleep disturbance, mild anemia, reduced muscle bulk and strength, increased body fat or body mass index, and diminished physical performance. ¹ Similar definitions have recently been developed by the Canadian Men’s Health Foundation Multidisciplinary Guidelines Task Force on Testosterone Deficiency.²In young men, hypogonadism is more commonly characterized by signs and symptoms from the first group, such as reduced libido and erectile dysfunction. This condition is most often caused by testicular or pituitary pathology, including hyperprolactinemia, pituitary or hypothalamic disorders, testicular disease, radiation exposure or genetic diseases such as Klinefelter syndrome.³ Testosterone replacement is indicated in these cases of “classic hypogonadism,” as it ameliorates the clinical symptoms.⁴In contrast, although these entities exist in older men too, they are less frequent causes of low testosterone than age-related changes. There is evidence that testosterone levels decline with age in all men, regardless of symptoms, at an estimated rate of 1%–3% per year.^5,6 One study found that serum testosterone levels were below the normal range in 20% of men in their 60s and in close to 50% of men in their 80s.⁷ However, the prevalence of symptomatic low testosterone (hypogonadism) is estimated by some to be much lower in this population, at about 2%.⁸ Given the high prevalence of low testosterone and more limited correlation with symptoms in aging men, it is uncertain to what extent this represents a physiologic or pathologic event.^6,7 Moreover, symptoms typically associated with low testosterone are less specific in older men and may be caused by other comorbidities. For example, erectile dysfunction can be the result of vascular insufficiency, neurologic impairment, psychogenic causes or substance use.⁹ Conditions such as diabetes mellitus and atherosclerosis are more common in older men, with up to 40% of men over 50 years of age having evidence of vascular insufficiency as the primary cause of their erectile dysfunction.¹⁰ Low libido similarly can result from psychiatric or medical conditions that are more common in older men.¹¹Currently, many clinicians diagnose hypogonadism in older men on the basis of low serum testosterone levels, with or without symptoms, largely on the assumption that this is a pathologic condition requiring treatment. The purpose of this study was to systematically review the available literature to estimate the accuracy and operating characteristics of signs and symptoms for predicting low testosterone in aging men.