20 research outputs found

    Phosphorus mobilizing consortium Mammoth P enhances plant growth

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    Global agricultural productivity may be constrained by the finite and limited supply of phosphorus (P), adding to the challenges in meeting the projected needs of a growing human population in the coming decades. In addition, when P fertilizers are added to soils, they can become bound to soils resulting in low fertilizer efficiency. However, P-mobilizing bacteria could potentially liberate soil-bound P, resulting in a higher plant P uptake and increased yield. Bacteria can mobilize P through several mechanisms, suggesting that consortia of P-bacteria may be more effective than single species. Species diversity can have a synergistic, or non-additive, effect on ecosystem functioning ("the whole is more than the sum of its parts") but rarely is the microbial community structure intentionally managed to improve plant nutrient uptake. We investigated whether inoculation of soils with a four-species bacterial community developed to mobilize soil P could increase plant productivity. In wheat and turf trials, we found that Mammoth P was able to deliver yields equivalent to those achieved using conventional fertilizer applications. Herbs and fruits showed that the combination of fertilizer with Mammoth P significantly increased productivity -in some cases productivity doubled. Metabolites produced by the Mammoth P consortium led to increased yields in some cases, suggesting that microbial products (produced in the absence of plants) played a role in enhancing plant productivity. Results from these trials indicate substantial potential of Mammoth P to enhance P supply to plants, improving P fertilizer use-efficiency and increasing agricultural productivity. 19 Agricultural productivity may be constrained in the 21 st Century by the finite supply of global a 20 phosphorus (P), adding to the challenges in meeting the projected needs of a growing human population 21 in the coming decades. In addition, when P fertilizers are added to soils, they can become bound to soils 22 resulting in low fertilizer efficiency. However, bacteria have the ability to mobilize soil bound P through 23 several mechanisms potentially resulting in a higher plant P uptake and increased yield. Furthermore, 24 species diversity can have a synergistic effect on ecosystem functioning ("the whole is more than the sum 25 of its parts") suggesting that bacterial communities, or consortia, may be more effective than single 26 species. However, in agriculture management practices, rarely is the soil microbial community structure 27 effectively manipulated to improve plant nutrient uptake. We investigated whether inoculation of soils 28 with a bacterial consortium developed to mobilize soil P named Mammoth P could increase plant 29 productivity. In turf, herbs and fruits, we showed that the combination of conventional inorganic fertilizer 30 combined with Mammoth P increased productivity up to twofold compared to the fertilizer treatments 31 without the Mammoth P inoculant. In wheat trials, we found that Mammoth P by itself was able to deliver 32 yields equivalent to those achieved with conventional inorganic fertilizer applications. The metabolites 33 produced by the consortium in Mammoth P likely played a role in enhancing plant productivity. Results 34 from this study indicate the substantial potential of Mammoth P to enhance P supply to plants, improving 35 P fertilizer use-efficiency and increasing agricultural productivity. 3

    LKB1 is required for hepatic bile acid transport and canalicular membrane integrity in mice

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    LKB1 is a ‘master’ protein kinase implicated in the regulation of metabolism, cell proliferation, cell polarity and tumorigenesis. However, the long-term role of LKB1 in hepatic function is unknown. In the present study, it is shown that hepatic LKB1 plays a key role in liver cellular architecture and metabolism. We report that liver-specific deletion of LKB1 in mice leads to defective canaliculi and bile duct formation, causing impaired bile acid clearance and subsequent accumulation of bile acids in serum and liver. Concomitant with this, it was found that the majority of BSEP (bile salt export pump) was retained in intracellular pools rather than localized to the canalicular membrane in hepatocytes from LLKB1KO (liver-specific Lkb1-knockout) mice. Together, these changes resulted in toxic accumulation of bile salts, reduced liver function and failure to thrive. Additionally, circulating LDL (low-density lipoprotein)-cholesterol and non-esterified cholesterol levels were increased in LLKB1KO mice with an associated alteration in red blood cell morphology and development of hyperbilirubinaemia. These results indicate that LKB1 plays a critical role in bile acid homoeostasis and that lack of LKB1 in the liver results in cholestasis. These findings indicate a novel key role for LKB1 in the development of hepatic morphology and membrane targeting of canalicular proteins

    Korarchaeota Diversity, Biogeography, and Abundance in Yellowstone and Great Basin Hot Springs and Ecological Niche Modeling Based on Machine Learning

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    Over 100 hot spring sediment samples were collected from 28 sites in 12 areas/regions, while recording as many coincident geochemical properties as feasible (>60 analytes). PCR was used to screen samples for Korarchaeota 16S rRNA genes. Over 500 Korarchaeota 16S rRNA genes were screened by RFLP analysis and 90 were sequenced, resulting in identification of novel Korarchaeota phylotypes and exclusive geographical variants. Korarchaeota diversity was low, as in other terrestrial geothermal systems, suggesting a marine origin for Korarchaeota with subsequent niche-invasion into terrestrial systems. Korarchaeota endemism is consistent with endemism of other terrestrial thermophiles and supports the existence of dispersal barriers. Korarchaeota were found predominantly in >55°C springs at pH 4.7–8.5 at concentrations up to 6.6×106 16S rRNA gene copies g−1 wet sediment. In Yellowstone National Park (YNP), Korarchaeota were most abundant in springs with a pH range of 5.7 to 7.0. High sulfate concentrations suggest these fluids are influenced by contributions from hydrothermal vapors that may be neutralized to some extent by mixing with water from deep geothermal sources or meteoric water. In the Great Basin (GB), Korarchaeota were most abundant at spring sources of pH<7.2 with high particulate C content and high alkalinity, which are likely to be buffered by the carbonic acid system. It is therefore likely that at least two different geological mechanisms in YNP and GB springs create the neutral to mildly acidic pH that is optimal for Korarchaeota. A classification support vector machine (C-SVM) trained on single analytes, two analyte combinations, or vectors from non-metric multidimensional scaling models was able to predict springs as Korarchaeota-optimal or sub-optimal habitats with accuracies up to 95%. To our knowledge, this is the most extensive analysis of the geochemical habitat of any high-level microbial taxon and the first application of a C-SVM to microbial ecology

    Fear of Childbirth in Nulliparous Women

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    Purpose: The relation between fear of childbirth (FoC) and gestational age is inconclusive, and self-reported need for help regarding this fear has never been investigated. This study aimed to determine the prevalence and course of FoC according to gestational age, to identify risk factors for the development of FoC, the influence of this fear on preferred mode of delivery, and self-reported need for help. Methods: Nulliparous pregnant women of all gestational ages completed an online survey. The study consisted of a cross-sectional and a longitudinal analysis. Women who completed the survey in the first or second trimester (T0) were approached again in their third trimester (T1). The Wijma Delivery Expectancy Questionnaire Version A (W-DEQ A) was used with a cut-off score ≥ 85 to define presence of fear of childbirth. Questionnaires indexing social support, anxiety, symptoms of depression, preferred mode of delivery, and self-reported need for help were included. Results: In total, 364 women were enrolled at T0, and 118 out of 184 eligible women were included in the longitudinal analysis. Point prevalence of FoC at T0 was 18.4% with no significant difference between trimesters. In the longitudinal sample, the prevalence of FoC decreased from 18.6% (T0) to 11.0% (T1), p = 0.004. Although mean scores for FoC decreased significantly, p < 0.001, scores increased in 41 (34.7%) women. The presence of FoC was associated with elevated anxiety, less family support, prenatal care of the obstetrician by choice, preference for a cesarean section, and for pain relief. Women with FoC were more likely to actively seek for help compared to women without FoC. Conclusion: While FoC is common in each trimester, prevalence decreases over the course of pregnancy. Women with FoC are often actively seeking for help, suggesting that this fear should be addressed better, and help should be offered accordingly

    Therapist perceptions of treating posttraumatic stress disorder in pregnancy: The VIP Study

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    There is no consensus on the treatment of posttraumatic stress disorder (PTSD) during pregnancy, and therapists' views on the matter are largely unknown. This cross-sectional study aimed to explore therapist beliefs and experiences regarding PTSD treatment during pregnancy. Participants were therapists (N = 301) with experience treating PTSD who completed an online survey. The primary outcome measure was the percentage of therapists who were experienced in treating PTSD symptoms during pregnancy; secondary outcome measures assessed preferred treatments for the general and pregnant populations, perceived reluctance to treat PTSD in pregnancy, and perceived effects and adverse events attributed to treatment for pregnant women and fetuses. The majority of participants (n = 246, 81.7%) had experience with treating PTSD during pregnancy. Eye movement desensitization and reprocessing was the preferred treatment for both the general and the pregnant populations. Almost half of the sample (48.8%) reported hearing that PTSD treatment in pregnancy could be harmful; 30.5% of therapists were reluctant to treat pregnant women with PTSD. Most therapists observed a clinically relevant posttreatment reduction of PTSD symptoms in pregnant women. Perceived adverse maternal and fetal events attributed to treatment were reported by 8.4% and 1.4% of therapists, respectively. Despite reluctance, most therapists reported treating PTSD during pregnancy. The results show that although therapists often reported hearing that treating PTSD during pregnancy was harmful, only a small percentage reported perceived adverse events, and treatment was often viewed as effective. These findings implicate a more positive view on the treatment of PTSD in pregnancy

    Los efectos del tratamiento del TEPT durante el embarazo: revisión sistemática y estudio de caso

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    Background: PTSD in pregnant women is associated with adverse outcomes for mothers and their children. It is unknown whether pregnant women with PTSD, or symptoms of PTSD, can receive targeted treatment that is safe and effective. Objective: The purpose of the present paper was to assess the effectiveness and safety of treatment for (symptoms of) PTSD in pregnant women. Method: A systematic review was conducted in accordance with the PRISMA guidelines in Pubmed, Embase, PsychINFO, and Cochrane. In addition, a case is presented of a pregnant woman with PTSD who received eye-movement desensitization and reprocessing (EMDR) therapy aimed at processing the memories of a previous distressing childbirth. Results: In total, 13 studies were included, involving eight types of interventions (i.e. trauma-focused cognitive behavioural therapy, exposure therapy, EMDR therapy, interpersonal psychotherapy, explorative therapy, self-hypnosis and relaxation, Survivor Moms Companion, and Seeking Safety Intervention). In three studies, the traumatic event pertained to a previous childbirth. Five studies reported obstetrical outcomes. After requesting additional information, authors of five studies indicated an absence of serious adverse events. PTSD symptoms improved in 10 studies. However, most studies carried a high risk of bias. In our case study, a pregnant woman with a PTSD diagnosis based on DSM-5 no longer fulfilled the criteria of PTSD after three sessions of EMDR therapy. She had an uncomplicated pregnancy and delivery. Conclusion: Despite the fact that case studies as the one presented here report no adverse events, and treatment is likely safe, due to the poor methodological quality of most studies it is impossible to allow inferences on the effects of any particular treatment of PTSD (symptoms) during pregnancy. Yet, given the elevated maternal stress and cortisol levels in pregnant women with PTSD, and the fact that so far no adverse effects on the unborn child have been reported associated with the application of trauma-focused therapy, treatment of PTSD during pregnancy is most likely safe

    Work-related adverse events leaving their mark: a cross-sectional study among Dutch gynecologists

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    Abstract Background Health care professionals who are frequently coping with traumatic events have an increased risk of developing a posttraumatic stress disorder. Research among physicians is scarce, and obstetrician-gynecologists may have a higher risk. Work-related traumatic events and posttraumatic stress disorder among obstetricians-gynecologists and the (desired) type of support were studied. Methods A questionnaire was emailed to all members of the Dutch Society of Obstetrics and Gynaecology, which included residents, attending, retired and non-practicing obstetricians-gynecologists. The questionnaire included questions about personal experiences and opinions concerning support after work-related events, and a validated questionnaire for posttraumatic stress disorder. Results The response rate was 42.8% with 683 questionnaires eligible for analysis. 12.6% of the respondents have experienced a work-related traumatic event, of which 11.8% met the criteria for current posttraumatic stress disorder. This revealed an estimated prevalence of 1.5% obstetricians-gynecologists with current posttraumatic stress disorder. 12% reported to have a support protocol or strategy in their hospital after adverse events. The most common strategies to cope with emotional events were: to seek support from colleagues, to seek support from family or friends, to discuss the case in a complication meeting or audit and to find distraction. 82% would prefer peer-support with direct colleagues after an adverse event. Conclusions This survey implies that work-related events can be traumatic and subsequently can lead to posttraumatic stress disorder. There is a high prevalence rate of current posttraumatic stress disorder among obstetricians-gynecologists. Often there is no standardized support after adverse events. Most obstetrician-gynecologists prefer peer-support with direct colleagues after an adverse event. More awareness must be created during medical training and organized support must be implemented
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