227 research outputs found
Low energy threshold corrections to neutrino masses and mixing angles
We compute the low energy threshold corrections to neutrino masses and mixing
in the Standard Model (SM) and its minimal supersymmetric version, using the
effective theory technique. We demonstrate that they stabilize the
renormalization group (RG) running with respect to the choice of the scale to
which the RG equation is integrated. This confirms the correctness of the
recent re-derivation of the RGE for the SM in hep-ph/0108005. The explicit
formulae for the low energy threshold corrections corrections can be applied to
specific models of neutrino masses and mixing.Comment: 20 pages, 2 postscript figure
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Improving field establishment of cacao (Theobroma cacao) through mulching, irrigation and shading
Establishment of young cacao trees in West Africa can be severely impeded by the on-set of the dry season. To address this issue, a field experiment was conducted in Ghana to examine whether different mulch treatments and irrigation applied during the dry season combined with over-head shade could improve survival, early growth and yield of cacao. The mulch treatments used were polyethylene film and coffee husks placed around the young plants. Irrigation was used as a positive control and no mulching or irrigation was a negative control. Three shade regimes were provided through different arrangements of Gliricidia sepium and plantains. Four different cacao clones were used in the study in a replicated split-plot design. Early growth of cacao was stimulated under the irrigation and plastic mulch treatments. Higher rates of photosynthesis during the dry season appeared to underlie these increases. Significantly higher early yields were also observed under the irrigation and coffee mulch treatments compared to the control. Plant survival varied significantly between treatments; irrigation was associated with the highest plant survival (94%), followed by the plastic mulch treatment (91%), coffee husk (82%) and the control (70%). There was also an increase in survival when more intense shading was used. Under zero mulch conditions, differences in survival were observed between clones. The clones P 30 [POS] and SCA 6 were more sensitive to drought (in terms of survival) than PA 150 and T 79/501. It is concluded that relatively simple mulching techniques or controlled irrigation in conjunction with appropriate shade management can significantly improve early establishment and cropping of cacao
O 1s excitation and ionization processes in the CO2 molecule studied via detection of low-energy fluorescence emission
Oxygen 1s excitation and ionization processes in the CO2 molecule have been studied with dispersed and non-dispersed fluorescence spectroscopy as well as with the vacuum ultraviolet (VUV) photon?photoion coincidence technique. The intensity of the neutral O emission line at 845 nm shows particular sensitivity to core-to-Rydberg excitations and core?valence double excitations, while shape resonances are suppressed. In contrast, the partial fluorescence yield in the wavelength window 300?650 nm and the excitation functions of selected O+ and C+ emission lines in the wavelength range 400?500 nm display all of the absorption features. The relative intensity of ionic emission in the visible range increases towards higher photon energies, which is attributed to O 1s shake-off photoionization. VUV photon?photoion coincidence spectra reveal major contributions from the C+ and O+ ions and a minor contribution from C2+. No conclusive changes in the intensity ratios among the different ions are observed above the O 1s threshold. The line shape of the VUV?O+ coincidence peak in the mass spectrum carries some information on the initial core excitatio
Tuning the energetics and tailoring the optical properties of silver clusters confined in zeolites
The integration of metal atoms and clusters in well-defined dielectric cavities is a powerful strategy to impart new properties to them that depend on the size and geometry of the confined space as well as on metal-host electrostatic interactions. Here, we unravel the dependence of the electronic properties of metal clusters on space confinement by studying the ionization potential of silver clusters embedded in four different zeolite environments over a range of silver concentrations. Extensive characterization reveals a strong influence of silver loading and host environment on the cluster ionization potential, which is also correlated to the cluster's optical and structural properties. Through fine-tuning of the zeolite host environment, we demonstrate photoluminescence quantum yields approaching unity. This work extends our understanding of structure property relationships of small metal clusters and applies this understanding to develop highly photoluminescent materials with potential applications in optoelectronics and bioimaging
Sporangia and Spores in the Fern Genera Spicantopsis and Struthiopteris (Blechnaceae, Polypodiopsida)
Struthiopteris (Blechnaceae) has recently been classified on the basis of molecular and morphological evidence, and some of its species are now included in the sister genus Spicantopsis. However, the lack of studies on several important morphological features impedes a sound assessment of their congruence with this new systematic arrangement, as well as of their range of variation and taxonomic value in this group of ferns. Here we present a study on the spores and sporangia using both light and scanning electron microscopy in Struthiopteris and Spicantopsis, using samples of all their species, and almost all their varieties. We provide full morphological descriptions of the spores and sporangia of all these taxa. We point out that the perispore structure and ornamentation and the number and the thickness of stomium cells in the sporangium clearly distinguish both generaThe Universidad Complutense de Madrid partially supported this research through the funding of a project PR26/16-20295, and a field trip to Iceland (International Mobility Program 2016
A randomised, double-blind, placebo-controlled trial of repeated nebulisation of non-viral cystic fibrosis transmembrane conductance regulator (CFTR) gene therapy in patients with cystic fibrosis
BACKGROUND: Cystic fibrosis (CF) is a chronic, life-limiting disease caused by mutations in the CF
transmembrane conductance regulator (CFTR) gene leading to abnormal airway surface ion transport,
chronic lung infections, inflammation and eventual respiratory failure. With the exception of the
small-molecule potentiator, ivacaftor (Kalydeco®, Vertex Pharmaceuticals, Boston, MA, USA), which is
suitable for a small proportion of patients, there are no licensed therapies targeting the basic defect.
The UK Cystic Fibrosis Gene Therapy Consortium has taken a cationic lipid-mediated CFTR gene therapy
formulation through preclinical and clinical development.
OBJECTIVE: To determine clinical efficacy of the formulation delivered to the airways over a period of
1 year in patients with CF.
DESIGN: This was a randomised, double-blind, placebo-controlled Phase IIb trial of the CFTR gene–liposome
complex pGM169/GL67A. Randomisation was performed via InForm™ version 4.6 (Phase Forward
Incorporated, Oracle, CA, USA) and was 1 : 1, except for patients in the mechanistic subgroups (2 : 1).
Allocation was blinded by masking nebuliser chambers.
SETTINGS: Data were collected in the clinical and scientific sites and entered onto a trial-specific InForm,
version 4.6 database.
PARTICIPANTS: Patients with CF aged ≥ 12 years with forced expiratory volume in the first second (FEV1)
between 50% and 90% predicted and any combination of CFTR mutations. The per-protocol group
(≥ 9 doses) consisted of 54 patients receiving placebo (62 randomised) and 62 patients receiving gene
therapy (78 randomised).
INTERVENTIONS: Subjects received 5 ml of nebulised pGM169/G67A (active) or 0.9% saline (placebo) at
28 (±5)-day intervals over 1 year.
MAIN OUTCOME MEASURES: The primary end point was the relative change in percentage predicted FEV1
over the 12-month period. A number of secondary clinical outcomes were assessed alongside safety
measures: other spirometric values; lung clearance index (LCI) assessed by multibreath washout; structural
disease on computed tomography (CT) scan; the Cystic Fibrosis Questionnaire – Revised (CFQ-R), a
validated quality-of-life questionnaire; exercise capacity and monitoring; systemic and sputum inflammatory
markers; and adverse events (AEs). A mechanistic study was performed in a subgroup in whom transgene
deoxyribonucleic acid (DNA) and messenger ribonucleic acid (mRNA) was measured alongside nasal and
lower airway potential difference.
RESULTS: There was a significant (p = 0.046) treatment effect (TE) of 3.7% [95% confidence interval (CI)
0.1% to 7.3%] in the primary end point at 12 months and in secondary end points, including forced vital
capacity (FVC) (p = 0.031) and CT gas trapping (p = 0.048). Other outcomes, although not reaching
statistical significance, favoured active treatment. Effects were noted by 1 month and were irrespective
of sex, age or CFTR mutation class. Subjects with a more severe baseline FEV1 had a FEV1 TE of 6.4%
(95% CI 0.8% to 12.1%) and greater changes in many other secondary outcomes. However, the more
mildly affected group also demonstrated benefits, particularly in small airway disease markers such as LCI.
The active group showed a significantly (p = 0.032) greater bronchial chloride secretory response. No
difference in treatment-attributable AEs was seen between the placebo and active groups.
CONCLUSIONS: Monthly application of the pGM169/GL67A gene therapy formulation was associated with
an improvement in lung function, other clinically relevant parameters and bronchial CFTR function,
compared with placebo.
LIMITATIONS: Although encouraging, the improvement in FEV1 was modest and was not accompanied by
detectable improvement in patients’ quality of life.
FUTURE WORK: Future work will focus on attempts to increase efficacy by increasing dose or frequency,
the coadministration of a CFTR potentiator, or the use of modified viral vectors capable of
repeated administration.
TRIAL REGISTRATION: ClinicalTrials.gov NCT01621867
Evaluation of protamines 1 and 2 transcript contents in spermatozoa from asthenozoospermic men.
During mammalian spermatogenesis, the chromatin structure undergoes substantial condensation. The key role in this process is played by protamines 1 and 2 (PRM1, PRM2). We attempted to compare the levels of PRM1 and PRM2 transcripts in mature spermatozoa of normospermic and asthenozoospermic men. Human ejaculates from normozoospermic (n=70) and asthenozoospermic (n=100) donors were purified by centrifugation through discontinuous Percoll density gradient. RNA was isolated from spermatozoa according to the ChomczyĂąski and Sacchi method, treated with DNase I, and reverse-transcribed into cDNA. Using reverse transcription and real-time quantitative polymerase chain reaction analysis, we found a reduction in the levels of PRM1 and PRM2 transcripts in spermatozoa from asthenozoospermic men, as compared to controls (
Benchmarking and reducing length of stay in Dutch hospitals
<p>Abstract</p> <p>Background</p> <p>To assess the development of and variation in lengths of stay in Dutch hospitals and to determine the potential reduction in hospital days if all Dutch hospitals would have an average length of stay equal to that of benchmark hospitals.</p> <p>Methods</p> <p>The potential reduction was calculated using data obtained from 69 hospitals that participated in the National Medical Registration (LMR). For each hospital, the average length of stay was adjusted for differences in type of admission (clinical or day-care admission) and case mix (age, diagnosis and procedure). We calculated the number of hospital days that theoretically could be saved by (i) counting unnecessary clinical admissions as day cases whenever possible, and (ii) treating all remaining clinical patients with a length of stay equal to the benchmark (15<sup>th </sup>percentile length of stay hospital).</p> <p>Results</p> <p>The average (mean) length of stay in Dutch hospitals decreased from 14 days in 1980 to 7 days in 2006. In 2006 more than 80% of all hospitals reached an average length of stay shorter than the 15th percentile hospital in the year 2000. In 2006 the mean length of stay ranged from 5.1 to 8.7 days. If the average length of stay of the 15<sup>th </sup>percentile hospital in 2006 is identified as the standard that other hospitals can achieve, a 14% reduction of hospital days can be attained. This percentage varied substantially across medical specialties. Extrapolating the potential reduction of hospital days of the 69 hospitals to all 98 Dutch hospitals yielded a total savings of 1.8 million hospital days (2006). The average length of stay in Dutch hospitals if all hospitals were able to treat their patients as the 15<sup>th </sup>percentile hospital would be 6 days and the number of day cases would increase by 13%.</p> <p>Conclusion</p> <p>Hospitals in the Netherlands vary substantially in case mix adjusted length of stay. Benchmarking – using the method presented – shows the potential for efficiency improvement which can be realized by decreasing inputs (e.g. available beds for inpatient care). Future research should focus on the effect of length of stay reduction programs on outputs such as quality of care.</p
Add-on treatment with nebulized hypertonic saline in a child with plastic bronchitis after the Glenn procedure
Plastic bronchitis (PB), although a rare cause of airway obstruction, has mortality rates up to 50% in children after Fontan-type cardiac surgery. We present the case of an 18-month-old female patient with PB following pneumonia. At 6 months of age, the patient underwent the Glenn procedure due to functionally univentricular heart. Fiberoptic bronchoscopy revealed complete blockage of the left bronchus by mucoid casts. Pharmacotherapy consisted of glucocorticosteroids, azithromycin, and enalapril maleate. The child also received nebulized 3% NaCl solution, which proved to be beneficial. In children submitted to Fontan-type procedures, physicians must be alert for PB, which can be triggered by respiratory tract infection
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