Summary
Peñahueca is an athalassohaline hypersaline inland ephemeral lake originated under semiarid conditions in the central Iberian Peninsula (Spain). Its chemical composition makes it extreme for ...microbial life as well as a terrestrial analogue of other planetary environments. To investigate the persistence of microbial life associated with sulfate‐rich crusts, we applied cultivation‐independent methods (optical and electron microscopy, 16S rRNA gene profiling and metagenomics) to describe the prokaryotic community and its associated viruses. The diversity for Bacteria was very low and was vastly dominated by endospore formers related to Pontibacillus marinus of the Firmicutes phylum. The archaeal assemblage was more diverse and included taxa related to those normally found in hypersaline environments. Several ‘metagenome assembled genomes’ were recovered, corresponding to new species of Pontibacillus, several species from the Halobacteria and one new member of the Nanohaloarchaeota. The viral assemblage, although composed of the morphotypes typical of high salt systems, showed little similarity to previously isolated/reconstructed halophages. Several putative prophages of Pontibacillus and haloarchaeal hosts were identified. Remarkably, the Peñahueca sulfate‐rich metagenome contained CRISPR‐associated proteins and repetitions which were over 10‐fold higher than in most hypersaline systems analysed so far.
Microbial dolomite in fresh water carbonate deposits García-Del-Cura, María Ángeles; Sanz-Montero, María Esther; De-los-Ríos, María Asunción ...
Sedimentology,
01/2014, Letnik:
61, Številka:
1
Journal Article
Recenzirano
This article reports evidence for biologically mediated precipitation of dolomite in a fresh water spring in the south‐east of Spain. Build‐ups in the spring consisted of calcite, minor dolomite, ...barite and gypsum crystals formed by the mineralisation of microbial biofilms and bryophytes. A detailed microscopic study, coupled with geochemical analysis of the dolomite‐precipitating biofilms, showed that dolomite crystals occurred in association with living coccoid micro‐organisms, providing strong evidence that micro‐organisms play a fundamental role in the precipitation of this mineral. Many of the calcite crystals observed were associated with extracellular polymeric substances. Moreover, microbial involvement in the precipitation of calcite was further supported by the presence of living cyanobacteria within the calcite crystals. Two different types of build‐up were found in the spring: soft spongy moss tufa and laminated crusts. Two types of crusts were identified as follows: simple pink crusts and laminated crusts, the latter forming in both sub‐aquatic and sub‐aerial environments. Sub‐aquatic accumulation of simple detached pink crust fragments occurred sporadically. Both tufa and the carbonate crusts hosted cyanobacterial‐dominated biofilms with different bacteria and diatoms and their extracellular polymeric substances. The δ13C values of calcite showed some biogenic involvement in the origin of this mineral. The δ18O values were similar in the tufa and carbonate crusts and corresponded to current climatological characteristics. The occurrence of different groups of minerals (carbonates and sulphates) in close spatial association with micro‐organisms suggests the presence of different macro‐environmental and micro‐environmental conditions that facilitate mineral precipitation within biofilms. These findings extend the known range of aerobic microbial dolomites to include springs, and show that the precipitation of both dolomite and calcite carbonates occurs while organisms are alive.
The kinetics of capillary imbibition into porous rocks is studied experimentally and theoretically. The Washburn law is modified by introducing various corrections relating to the microstructure of ...the rocks, such as tortuosity, pore shape (obtained experimentally), and applying the effective medium approximation (EMA) in order to calculate the effective radius that defines the hydraulic conductance and the topology of the capillary imbibition. The application of the EMA shows that capillary imbibition is mainly produced in 1-D, and the pore structure is constituted by different pore throats in series, linked by chamber pores. The capillary process has been discussed as a function of their petrography and pore structure. Our study of the Washburn equation and the addition of correction factors for the pore structure allows a very accurate prediction of the weight rate.
ObjectivesTo compare the effectiveness of oral versus intramuscular (IM) vitamin B12 (VB12) in patients aged ≥65 years with VB12 deficiency.DesignPragmatic, randomised, non-inferiority, multicentre ...trial in 22 primary healthcare centres in Madrid (Spain).Participants283 patients ≥65 years with VB12 deficiency were randomly assigned to oral (n=140) or IM (n=143) treatment arm.InterventionsThe IM arm received 1 mg VB12 on alternate days in weeks 1–2, 1 mg/week in weeks 3–8 and 1 mg/month in weeks 9–52. The oral arm received 1 mg/day in weeks 1–8 and 1 mg/week in weeks 9–52.Main outcomesSerum VB12 concentration normalisation (≥211 pg/mL) at 8, 26 and 52 weeks. Non-inferiority would be declared if the difference between arms is 10% or less. Secondary outcomes included symptoms, adverse events, adherence to treatment, quality of life, patient preferences and satisfaction.ResultsThe follow-up period (52 weeks) was completed by 229 patients (80.9%). At week 8, the percentage of patients in each arm who achieved normal B12 levels was well above 90%; the differences in this percentage between the oral and IM arm were −0.7% (133 out of 135 vs 129 out of 130; 95% CI: −3.2 to 1.8; p>0.999) by per-protocol (PPT) analysis and 4.8% (133 out of 140 vs 129 out of 143; 95% CI: −1.3 to 10.9; p=0.124) by intention-to-treat (ITT) analysis. At week 52, the percentage of patients who achieved normal B12 levels was 73.6% in the oral arm and 80.4% in the IM arm; these differences were −6.3% (103 out of 112 vs 115 out of 117; 95% CI: −11.9 to −0.1; p=0.025) and −6.8% (103 out of 140 vs 115 out of 143; 95% CI: −16.6 to 2.9; p=0.171), respectively. Factors affecting the success rate at week 52 were age, OR=0.95 (95% CI: 0.91 to 0.99) and having reached VB12 levels ≥281 pg/mL at week 8, OR=8.1 (95% CI: 2.4 to 27.3). Under a Bayesian framework, non-inferiority probabilities (Δ>−10%) at week 52 were 0.036 (PPT) and 0.060 (ITT). Quality of life and adverse effects were comparable across groups. 83.4% of patients preferred the oral route.ConclusionsOral administration was no less effective than IM administration at 8 weeks. Although differences were found between administration routes at week 52, the probability that the differences were below the non-inferiority threshold was very low.Trial registration numbersNCT 01476007; EUDRACT (2010-024129-20).
The rates of exclusive breastfeeding at 6 months in Spain are far from recommended by the World Health Organization, which is 50% by 2025. Evidence of the effectiveness of group interventions in late ...postpartum is limited. The objective of this study was to evaluate the effectiveness of the PROLACT group educational intervention for increasing the proportion of mother-child dyads with exclusive breastfeeding at 6 months compared to the usual practice in primary care.
Multicentre cluster randomized clinical trial. A total of 434 mother-child dyads who breastfed exclusively in the first 4 weeks of the children's life and agreed to participate were included. The main outcome was exclusive breastfeeding at 6 months. Secondary variables were type of breastfeeding, reasons for abandonment, degree of adherence and satisfaction with the intervention. To study the effectiveness, the difference in the proportions of dyads with exclusive breastfeeding at 6 months was calculated, and the relative risk (RR) and number needed to treat (NNT) were calculated with their 95% CIs. To study the factors associated with the maintenance of exclusive breastfeeding at 6 months, a multilevel logistic regression model was fitted. All analyses were performed to intention to treat.
The percentage of dyads with exclusive breastfeeding at 6 months was 22.4% in the intervention group and 8.8% in the control group. PROLACT intervention obtained an RR =2.53 (95% CI: 1.54-4.15) and an NNT = 7 (95%CI: 5-14). The factors associated with exclusive breastfeeding at 6 months were the PROLACT intervention, OR = 3.51 (95%CI: 1.55-7.93); age > 39 years, OR = 2.79 (95%CI: 1.02-7.6); previous breastfeeding experience, OR = 2.61 (95%CI: 1.29-5.29); income between 500 and 833.33 €, OR = 3.52 (95%CI 1.47-8.47).); planning to start work before the infant was 6 months old, OR = 0.35 (0.19-0.63) .
The PROLACT intervention in primary care is more effective than the usual practice for maintaining exclusive breastfeeding at 6 months, and can therefore be considered evidence-based practice for implementation in standard practice.
The trial was registered with ClinicalTrials.gov under code number NCT01869920 (03/06/2013).
The Quero Playa Lake is an ephemeral saline playa lake located in the La Mancha region of central Spain. In this study, a daily monitoring of the brine physical properties, water activity, brine ...depth and main climatic parameters was simultaneously carried out together with determining the precipitation sequence of minerals. Field data were compared with the results of simulating the water evaporation in an environmental chamber. In this simulation, a similar hydrochemical composition for the saline lake was used, and the main climatic parameters, temperature and humidity, were controlled.
The water balance equation for saline lakes has usually been described using the Wood and Sanford equation Econ. Geol., 85(1990) 1226–1235. Our experimental results required us to revise the water balance equation for the brine depth variations (d
h/d
t), that may be expressed as follows:
dh
dt
=p
1+k
A
B
A
L
+S
I
−S
O
−ξ−H+D,
where
p (mm) is the precipitation;
k is the drainage coefficient of the lake;
A
L is the lake surface;
A
B is the drainage basin surface;
S
I and
S
O are the contribution of influent and effluent seepage to the depth of brine in the lake. The term
ξ is the evaporation/condensation, defined as
ξ=
kp
W(
a
W−RH), where
k is the mass transfer coefficient (Dalton's equation);
p
W is the water pressure in equilibrium with the air;
a
W is the water activity of the brine; RH is the relative humidity. The other terms:
H and
D, correct the brine depth loss or/and gain a consequence of hydrated saline mineral precipitation and early diagenetic hydration/dehydration reactions.
As a consequence of the above, we suggest that the water balance equation for saline lakes can be an important consideration in the interpretation of their evolution. The precipitation of hydrated saline minerals and the early diagenetic dehydration/hydration reactions imply changes in the d
h/d
t curves. As a result, the interpretation of the sequence of primary saline minerals in older evaporitic deposits may be used as a paleoenvironmental marker.
The oral administration of vitamin B12 offers a potentially simpler and cheaper alternative to parenteral administration, but its effectiveness has not been definitively demonstrated. The following ...protocol was designed to compare the effectiveness of orally and intramuscularly administered vitamin B12 in the treatment of patients ≥65 years of age with vitamin B12 deficiency.
The proposed study involves a controlled, randomised, multicentre, parallel, non-inferiority clinical trial lasting one year, involving 23 primary healthcare centres in the Madrid region (Spain), and patients ≥65 years of age. The minimum number of patients required for the study was calculated as 320 (160 in each arm). Bearing in mind an estimated 8-10% prevalence of vitamin B12 deficiency among the population of this age group, an initial sample of 3556 patients will need to be recruited. Eligible patients will be randomly assigned to one of the two treatment arms. In the intramuscular treatment arm, vitamin B12 will be administered as follows: 1 mg on alternate days in weeks 1 and 2, 1 mg/week in weeks 3-8,and 1 mg/month in weeks 9-52. In the oral arm, the vitamin will be administered as: 1 mg/day in weeks 1-8 and 1 mg/week in weeks 9-52. The main outcome variable to be monitored in both treatment arms is the normalisation of the serum vitamin B12 concentration at weeks 8, 26 and 52; the secondary outcome variables include the serum concentration of vitamin B12 (in pg/ml), adherence to treatment, quality of life (EuroQoL-5D questionnaire), patient 3satisfaction and patient preferences. All statistical tests will be performed with intention to treat and per protocol. Logistic regression with random effects will be used to adjust for prognostic factors. Confounding factors or factors that might alter the effect recorded will be taken into account in analyses.
The results of this study should help establish, taking quality of life into account, whether the oral administration of vitamin B12 is an effective alternative to its intramuscular administration. If this administration route is effective, it should provide a cheaper means of treating vitamin B12 deficiency while inducing fewer adverse effects. Having such an alternative would also allow patient preferences to be taken into consideration at the time of prescribing treatment.
This trial has been registered with ClinicalTrials.gov, number NCT 01476007, and under EUDRACT number 2010-024129-20.
Provider: - Institution: - Data provided by Europeana Collections- En preliminares: Asociación de Geógrafos Españoles, Grupo de Trabajo de Geogrfía Física ; Universidad de Castilla-La Mancha, ...Departamento de Geografía y Ordenación del Territorio.- All metadata published by Europeana are available free of restriction under the Creative Commons CC0 1.0 Universal Public Domain Dedication. However, Europeana requests that you actively acknowledge and give attribution to all metadata sources including Europeana
Provider: - Institution: - Data provided by Europeana Collections- En preliminares: Asociación de Geógrafos Españoles, Grupo de Trabajo de Geogrfía Física ; Universidad de Castilla-La Mancha, ...Departamento de Geografía y Ordenación del Territorio.- All metadata published by Europeana are available free of restriction under the Creative Commons CC0 1.0 Universal Public Domain Dedication. However, Europeana requests that you actively acknowledge and give attribution to all metadata sources including Europeana
Medically unexplained symptoms are an important mental health problem in primary care and generate a high cost in health services.Cognitive behavioral therapy and psychodynamic therapy have proven ...effective in these patients. However, there are few studies on the effectiveness of psychosocial interventions by primary health care. The project aims to determine whether a cognitive-behavioral group intervention in patients with medically unexplained symptoms, is more effective than routine clinical practice to improve the quality of life measured by the SF-12 questionary at 12 month.
This study involves a community based cluster randomized trial in primary healthcare centres in Madrid (Spain). The number of patients required is 242 (121 in each arm), all between 18 and 65 of age with medically unexplained symptoms that had seeked medical attention in primary care at least 10 times during the previous year. The main outcome variable is the quality of life measured by the SF-12 questionnaire on Mental Healthcare. Secondary outcome variables include number of consultations, number of drug (prescriptions) and number of days of sick leave together with other prognosis and descriptive variables. Main effectiveness will be analyzed by comparing the percentage of patients that improve at least 4 points on the SF-12 questionnaire between intervention and control groups at 12 months. All statistical tests will be performed with intention to treat. Logistic regression with random effects will be used to adjust for prognostic factors. Confounding factors or factors that might alter the effect recorded will be taken into account in this analysis.
This study aims to provide more insight to address medically unexplained symptoms, highly prevalent in primary care, from a quantitative methodology. It involves intervention group conducted by previously trained nursing staff to diminish the progression to the chronicity of the symptoms, improve quality of life, and reduce frequency of medical consultations.
The trial was registered with ClinicalTrials.gov, number NCT01484223 http://ClinicalTrials.gov.
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