98 research outputs found
Antifungal Activity of Selected Indigenous Pseudomonas and Bacillus from the Soybean Rhizosphere
The purpose of this study was to isolate and select indigenous soil Pseudomonas and Bacillus bacteria capable of developing multiple mechanisms of action related to the biocontrol of phytopathogenic fungi affecting soybean crops. The screening procedure consisted of antagonism tests against a panel of phytopathogenic fungi, taxonomic identification, detection by PCR of several genes related to antifungal activity, in vitro detection of the antifungal products, and root colonization assays. Two isolates, identified and designated as Pseudomonas fluorescens BNM296 and Bacillus amyloliquefaciens BNM340, were selected for further studies. These isolates protected plants against the damping-off caused by Pythium ultimum and were able to increase the seedling emergence rate after inoculation of soybean seeds with each bacterium. Also, the shoot nitrogen content was higher in plants when seeds were inoculated with BNM296. The polyphasic approach of this work allowed us to select two indigenous bacterial strains that promoted the early development of soybean plants
Conformal invariance: from Weyl to SO(2,d)
The present work deals with two different but subtilely related kinds of
conformal mappings: Weyl rescaling in dimensional spaces and SO(2,d)
transformations. We express how the difference between the two can be
compensated by diffeomorphic transformations. This is well known in the
framework of String Theory but in the particular case of spaces. Indeed,
the Polyakov formalism describes world-sheets in terms of two-dimensional
conformal field theory. On the other hand, B. Zumino had shown that a classical
four-dimensional Weyl-invariant field theory restricted to live in Minkowski
space leads to an SO(2,4)-invariant field theory. We extend Zumino's result to
relate Weyl and SO(2,d) symmetries in arbitrary conformally flat spaces (CFS).
This allows us to assert that a classical -invariant field does not
distinguish, at least locally, between two different -dimensional CFSs.Comment: 5 pages, no figures. There are slight modifications to match with the
published versio
The unexpected resurgence of Weyl geometry in late 20-th century physics
Weyl's original scale geometry of 1918 ("purely infinitesimal geometry") was
withdrawn by its author from physical theorizing in the early 1920s. It had a
comeback in the last third of the 20th century in different contexts: scalar
tensor theories of gravity, foundations of gravity, foundations of quantum
mechanics, elementary particle physics, and cosmology. It seems that Weyl
geometry continues to offer an open research potential for the foundations of
physics even after the turn to the new millennium.Comment: Completely rewritten conference paper 'Beyond Einstein', Mainz Sep
2008. Preprint ELHC (Epistemology of the LHC) 2017-02, 92 pages, 1 figur
Quality of life assessed with the medical outcomes study short form 36-item health survey of patients on renal replacement therapy: A systematic review and meta-analysis
Objectives: The Medical Outcomes Study Short Form
36-Item Health Survey (SF-36) is the most widely used
generic instrument to estimate quality of life of patients on
renal replacement therapy. Purpose of this study was to summarize
and compare the published literature on quality of life
of hemodialysis (HD), peritoneal dialysis (PD), and renal
transplant (RTx) patients.
Methods: We used random-effects regression analyses to
compare the SF-36 scores across treatment groups and
adjusted this comparison for age and prevalence of diabetes
using random-effects meta-regression analyses.
Results: We found 52 articles that met the inclusion criteria,
reporting quality of life of 36,582 patients. The unadjusted
scores of all SF-36 health dimensions were not significantly
different between HD and PD patients, but the scores of RTx
patients were higher than those of dialysis patients, except for
the dimensions Mental Health and Bodily Pain. Point differences
between dialysis and RTx patients varied from 2 to 32.
With adjustment for age and diabetes, the differences became
smaller (point difference 2–22). The significance of the differences
of both dialysis groups compared with RTx recipients
disappeared for the dimensions Vitality and Social
Functioning. The significance of the differences between HD
and RTx patients disappeared on the dimensions Physical
Functioning, Role Physical, and Bodily Pain.
Conclusion: We conclude that dialysis patients have a lower
quality of life than RTx patients, but this difference can
partly be explained by differences in age and prevalence of
diabetes.
Keywords: hemodialysis, meta-analysis, peritoneal dialysis,
quality of life, renal transplantation
Defensive coping and health-related quality of life in chronic kidney disease: a cross-sectional study
<p>Abstract</p> <p>Background</p> <p>Coping with the stresses of chronic disease is considered as a key factor in the perceived impairment of health related quality of life (HRQL). Little is known though about these associations in chronic kidney disease (CKD). The present study aimed to investigate the relationship of defensive coping and HRQL among patients in different CKD stages, after adjusting for psychological distress, sociodemographic and disease-related variables.</p> <p>Methods</p> <p>The sample consisted of 98 CKD patients, attending a university nephrology department. Seventy-nine (79) pre-dialysis patients of disease stages 3 to 4 and 19 dialysis patients were included. HRQL was assessed by the 36-item Short-Form health survey (SF-36), defensive coping by the Rationality/Emotional Defensiveness (R/ED) scale of the Lifestyle Defense Mechanism Inventory (LDMI) and psychological distress by the depression and anxiety scales of the revised Hopkins Symptom CheckList (SCL-90-R). Regression analyses were carried out to examine the association between SF-36 dimensions and defensive coping style.</p> <p>Results</p> <p>Patients on dialysis had worse scores on SF-36 scales measuring physical aspects of HRQL. In the fully adjusted analysis, a higher defensive coping score was significantly associated with a lower score on the mental component summary (MCS) scale of the SF-36 (worse mental health). In contrast, a higher defensive score showed a small positive association with the physical component summary (PCS) scale of the SF-36 (better health), but this was marginally significant.</p> <p>Conclusions</p> <p>The results provided evidence that emotional defensiveness as a coping style tends to differentially affect the mental and the physical component of HRQL in CKD. Clinicians should be aware of the effects of long-term denial and could examine the possibility of screening for defensive coping and depression in recently diagnosed CKD patients with the aim to improve both physical and mental health.</p
Iron Behaving Badly: Inappropriate Iron Chelation as a Major Contributor to the Aetiology of Vascular and Other Progressive Inflammatory and Degenerative Diseases
The production of peroxide and superoxide is an inevitable consequence of
aerobic metabolism, and while these particular "reactive oxygen species" (ROSs)
can exhibit a number of biological effects, they are not of themselves
excessively reactive and thus they are not especially damaging at physiological
concentrations. However, their reactions with poorly liganded iron species can
lead to the catalytic production of the very reactive and dangerous hydroxyl
radical, which is exceptionally damaging, and a major cause of chronic
inflammation. We review the considerable and wide-ranging evidence for the
involvement of this combination of (su)peroxide and poorly liganded iron in a
large number of physiological and indeed pathological processes and
inflammatory disorders, especially those involving the progressive degradation
of cellular and organismal performance. These diseases share a great many
similarities and thus might be considered to have a common cause (i.e.
iron-catalysed free radical and especially hydroxyl radical generation). The
studies reviewed include those focused on a series of cardiovascular, metabolic
and neurological diseases, where iron can be found at the sites of plaques and
lesions, as well as studies showing the significance of iron to aging and
longevity. The effective chelation of iron by natural or synthetic ligands is
thus of major physiological (and potentially therapeutic) importance. As
systems properties, we need to recognise that physiological observables have
multiple molecular causes, and studying them in isolation leads to inconsistent
patterns of apparent causality when it is the simultaneous combination of
multiple factors that is responsible. This explains, for instance, the
decidedly mixed effects of antioxidants that have been observed, etc...Comment: 159 pages, including 9 Figs and 2184 reference
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