Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 22
Filter
1.
Eur J Med Genet ; 66(1): 104651, 2023 Jan.
Article in English | MEDLINE | ID: mdl-36404488

ABSTRACT

BACKGROUND: Diagnosis and treatment of 22q11.2 deletion syndrome (22q11.2DS) have led to improved life expectancy and achievement of adulthood. Limited data on long-term outcomes reported an increased risk of premature death for cardiovascular causes, even without congenital heart disease (CHD). The aim of this study was to assess the cardiac function in adolescents and young adults with 22q11.2DS without CHDs. METHODS: A total of 32 patients (20M, 12F; mean age 26.00 ± 8.08 years) and a healthy control group underwent transthoracic echocardiography, including Tissue Doppler Imaging (TDI) and 2-dimensional Speckle Tracking Echocardiography (2D-STE). RESULTS: Compared to controls, 22q11.2DS patients showed a significant increase of the left ventricle (LV) diastolic and systolic diameters (p = 0.029 and p = 0.035 respectively), interventricular septum thickness (p = 0.005), LV mass index (p < 0.001) and aortic root size (p < 0.001). 2D-STE analysis revealed a significant reduction of LV global longitudinal strain (p < 0.001) in 22q11.2DS than controls. Moreover, several LV diastolic parameters were significantly different between groups. CONCLUSIONS: Our results suggest that an echocardiographic follow-up in 22q11.2DS patients without CHDs can help to identify subclinical impairment of the LV and evaluate a potential progression of aortic root dilation over time, improving outcomes, reducing long-term complications and allowing for a better prognosis.


Subject(s)
DiGeorge Syndrome , Heart Defects, Congenital , Humans , Young Adult , Adolescent , Adult , Echocardiography/methods , Heart Ventricles/diagnostic imaging , Prognosis
2.
Nat Commun ; 13(1): 7752, 2022 12 14.
Article in English | MEDLINE | ID: mdl-36517483

ABSTRACT

Numerous studies have demonstrated that biodiversity drives ecosystem functioning, yet how biodiversity loss alters ecosystems functioning and stability in the long-term lacks experimental evidence. We report temporal effects of species richness on community productivity, stability, species asynchrony, and complementarity, and how the relationships among them change over 17 years in a grassland biodiversity experiment. Productivity declined more rapidly in less diverse communities resulting in temporally strengthening positive effects of richness on productivity, complementarity, and stability. In later years asynchrony played a more important role in increasing community stability as the negative effect of richness on population stability diminished. Only during later years did species complementarity relate to species asynchrony. These results show that species complementarity and asynchrony can take more than a decade to develop strong stabilizing effects on ecosystem functioning in diverse plant communities. Thus, the mechanisms stabilizing ecosystem functioning change with community age.


Subject(s)
Ecosystem , Grassland , Biodiversity , Plants , Biomass
3.
Curr Psychol ; : 1-10, 2022 Aug 06.
Article in English | MEDLINE | ID: mdl-35967493

ABSTRACT

The COVID-19 pandemic could be a threat for the health status of children with a chronic condition. The present study aimed to explore parents' and children's psychological adjustment during the current pandemic, pursuing a triple objective: to compare the psychological adjustment of parents of children with pediatric rheumatic diseases (PRDs) and parents of healthy children; to analyze children's psychological symptoms (emotional problems and hyperactivity) before and during the COVID-19 pandemic, and with or without a PRDs diagnosis; to explore the associations of children's emotional problems and hyperactivity with parents' psychological adjustment, parent-child interactions and belonging or not to families with PRDs. This cross-sectional study involved 56 parents of children with PRDs and 53 parents of healthy children. Self-report questionnaires about parents' depression, anxiety, parenting stress, and children's emotional symptoms and hyperactivity-inattention were administered. No differences were detected on psychological adjustment between parents of children with PRDs and parents of healthy children. Parents of children with PRDs reported statistically significant higher levels of children's emotional problems and hyperactivity before the pandemic, compared to parents of healthy children; during COVID-19 pandemic, emotional symptoms increased for both groups, while hyperactivity-inattention symptoms increased only in the group of healthy children. Children's emotional difficulties were associated with higher levels of parental anxiety, worse parent-child interaction and having PRDs; children's hyperactivity symptoms were related to parent-child difficult interaction and higher levels of parental depression. Findings suggest the importance to target the children in relation to their parents, when approaching the psychological aspects of PRDs.

4.
Children (Basel) ; 9(7)2022 Jul 14.
Article in English | MEDLINE | ID: mdl-35884037

ABSTRACT

OBJECTIVE: To evaluate whether the use of a surgical and N95 mask for overweight and obese children was associated with respiratory distress. METHODS: We enrolled 15 healthy and 14 overweight or obese children. We performed two sessions: one wearing a surgical, the other an N95 mask. We tracked changes in partial pressure of end-tidal carbon dioxide (PETCO2), oxygen saturation (SaO2), pulse rate (PR), and respiratory rate (RR) during a 72 min test: 30 min without a mask, 30 min wearing a mask, and then during a 12 min walking test. RESULTS: In healthy children, there was no significant change in SaO2 and PETCO2 during the study; there was a significant increase in PR and RR after the walking test with both the masks. In overweight or obese children, there was no significant change in SaO2 during the study period; there was a significant increase in PETCO2 as fast as wearing the mask and an increase in PETCO2, PR, and RR after walking test. After the walking test, we showed a significant correlation between PETCO2 and body mass index. CONCLUSION: Overweight or Obese children who wear a mask are more prone to developing respiratory distress, which causes them to remove it frequently. In a crowded environment, they are at greater risk of infection. For this reason, it is desirable that they attend environments where everyone uses a mask.

5.
Ital J Pediatr ; 48(1): 79, 2022 May 21.
Article in English | MEDLINE | ID: mdl-35598023

ABSTRACT

BACKGROUND: SARS-CoV-2 infection in the pediatric age group has a milder course than in adults, but in some cases even children may present with severe forms or develop long-term consequences. The aim of this study was to analyze the clinical features, long-term effects, lifestyle changes and psychological effects of SARS-CoV-2 infection in a pediatric sample of the Italian population. METHODS: We conducted a telephone survey among 3075 children infected with SARS-CoV-2 in the Latina Local Health Authority. Outcomes included: clinical features of infection, long-term symptoms, lifestyle changes and emotional symptoms during the illness. The information obtained was automatically linked to a spreadsheet and analyzed. RESULTS: One thousand four hundred thirteen children agreed to participate in the study; the mean age was 112.8 ± 21.9 months. Children were infected mainly inside familial clusters (59.6%; n = 842); 99% (n = 1399) of children were asymptomatic or exhibited mild symptoms. 20% (n = 259) of children experienced long-term symptoms; risk factors were: older age, higher body mass index and longer duration of infection. Throughout the period of infection, children spent most of the time on devices like tv-video, social media and mobile phone for non-educational activities. 58.8% (n = 620) of parents expressed a negative opinion about distance learning. Finally, we observed that 49,6% (n = 532) of children experienced psychological symptoms during quarantine period. CONCLUSION: Despite a lower susceptibility to COVID-19 in children, it is important to keep the focus high in children, both because of the possible long symptoms after infection and the impact on a children's mental and physical health due to pandemic. We believe that the return to school or other extracurricular activities are important to correct some of the risk factors for the long COVID syndrome, as obesity, and to limit the cultural damage generated by distance learning and psychological effects related to restrictive measures.


Subject(s)
COVID-19 , Adult , COVID-19/complications , COVID-19/epidemiology , Child , Humans , Pandemics , Quarantine , SARS-CoV-2 , Post-Acute COVID-19 Syndrome
6.
J Pediatr Gastroenterol Nutr ; 74(5): 599-604, 2022 05 01.
Article in English | MEDLINE | ID: mdl-35129153

ABSTRACT

OBJECTIVES: The occurrence of thrombotic events in adult patients with inflammatory bowel disease (IBD) is linked to multiple interactions between hereditary and acquired risk factors. There are few published data concerning children with iBD. The aim of this study was to investigate the presence of thromboembolic risk factors also in children with iBD. METHODS: We enrolled three groups of children: one with Crohn disease (cD), one with ulcerative colitis (Uc), and a control group of healthy subjects. For all the participants the potential thromboembolic risk was evaluated clinically and with laboratory tests. RESULTS: We studied: 30 children (25.6%) with CD, 28 (23.9%) with UC, and 59 (50.4%) healthy control subjects. Regarding Pediatric Crohn Disease Activity Index, no significant differences between thromboembolic risk factors and disease activity were detected. Instead, in the patients with UC, stratified with the Pediatric Ulcerative Colitis Activity Index, there was a statistically significant difference in serum fibrinogen levels between patients with mild and moderate/severe disease [3.8 (3.2-4.5) g/L vs 5.7 (4.8-6.2) g/L, P  < 0.0032]. serum homocysteine levels were lower in healthy controls than in CD (P = 0.176) and UC (P = 0.026). An increased level ofhomocysteine in UC with a homozygous mutation in the methylene tetrahydrofolate reductase C677T gene was also observed. CONCLUSIONS: Our study showed that children with IBD have clinical features, acquired and congenital factors that can increase thrombotic risk, similarly to adults.


Subject(s)
Colitis, Ulcerative , Crohn Disease , Inflammatory Bowel Diseases , Adult , Child , Chronic Disease , Colitis, Ulcerative/complications , Colitis, Ulcerative/genetics , Crohn Disease/complications , Crohn Disease/genetics , Humans , Inflammatory Bowel Diseases/complications , Inflammatory Bowel Diseases/genetics , Mutation , Risk Factors
7.
Children (Basel) ; 8(12)2021 Dec 15.
Article in English | MEDLINE | ID: mdl-34943379

ABSTRACT

OBJECTIVE: To evaluate how the restrictive measures implemented during the SARS-CoV-2 pandemic have influenced the incidence of the most common children's diseases and the consumption of medications in 2020 compared to 2019. METHODS: We involved all family pediatricians of the local health authority of Latina, from which we requested data of monthly visits in 2019 and 2020 for six common diseases disseminated through droplets and contact, and the territorial and integrative pharmaceutical unit of the area, from which we requested data of the net expenditure regarding the most commonly used drugs at pediatric age. RESULTS: There was significant reduction in the incidence of the evaluated diseases and in the consumption of investigated drugs between 2019 and 2020 in the months when the restrictive measures were in place, with an attenuation of this effect during the months of the gradual loosening of those measures. CONCLUSION: Nonpharmaceutical intervention measures have caused changes in the diffusion of common pediatric diseases. We believe that the implementation of a reasonable containment strategy, even outside of the pandemic, could positively influence the epidemiology of infectious and allergic diseases in children, and healthcare system spending.

8.
Data Brief ; 39: 107550, 2021 Dec.
Article in English | MEDLINE | ID: mdl-34778496

ABSTRACT

In response to the current COVID-19 pandemic, universal face masking represents one of the most important strategies to limit the spread of infection. However, their use in children is still highly debated (Esposito and Principi, 2020; Esposito et al., 2020) and there are few data (Lubrano et al., 2021a, 2021b) describing their possible effects on respiratory function in children. A dataset in this paper presents a comparison of the data related to the effects on respiratory function of children wearing a filtering facepiece 2 (N95 mask) with or without exhalation valve. 22 healthy children were randomly assigned to two groups, both groups wearing an N95 mask: one without an exhalation valve (group A), another with an exhalation valve (group B). Children were subjected to a 72 min test: the first 30 min without mask, then 30 min wearing face mask while practiced their usual play activity; finally, 12 min, with face mask in place, while they walked as in a walking test. They were monitored through to microstream capnography system (Rad-97TM with Nomo-Line Capnography, Masimo, Irvine, CA, USA) to log oxygen saturation (SpO2) and respiratory rate (RR). We use the Wilcoxon test to analyzed the differences between the parameters recorded during the study in group A and B. Data analysis was performed using JMP14.3.0 program for Mac by SAS Institute inc.

9.
J Pediatr ; 237: 143-147, 2021 10.
Article in English | MEDLINE | ID: mdl-34043996

ABSTRACT

OBJECTIVE: To assess whether use of an N95 mask by children is associated with episodes of desaturation or respiratory distress. STUDY DESIGN: Twenty-two healthy children were assigned at random to 1 of 2 groups: one group wearing N95 masks without an exhalation valve and the other group wearing N95 masks with an exhalation valve. We tracked changes in partial pressure of end-tidal carbon dioxide (PETCO2), oxygen saturation, pulse rate, and respiratory rate over 72 minutes of mask use. All subjects were monitored every 15 minutes, the first 30 minutes while not wearing a mask and the next 30 minutes while wearing a mask. They then performed a 12-minute walking test. RESULTS: The children did not experience a statistically significant change in oxygen saturation or pulse rate during the study. There were significant increases in respiratory rate and PETCO2 in the children wearing an N95 mask without an exhalation valve, whereas these increases were seen in the children wearing a mask with an exhalation valve only after the walking test. CONCLUSIONS: The use of an N95 mask could potentially cause breathing difficulties in children if the mask does not have an exhalation valve, particularly during a physical activity. We believe that wearing a surgical mask may be more appropriate for children.


Subject(s)
N95 Respirators/adverse effects , Respiratory Insufficiency/etiology , Biomarkers/metabolism , Carbon Dioxide/metabolism , Child , Child, Preschool , Exercise/physiology , Female , Heart Rate , Humans , Male , Oxygen/metabolism , Respiratory Function Tests , Respiratory Insufficiency/diagnosis , Respiratory Insufficiency/metabolism , Respiratory Rate , Risk Factors , Walk Test
10.
Birth Defects Res ; 112(10): 725-731, 2020 06.
Article in English | MEDLINE | ID: mdl-32558384

ABSTRACT

BACKGROUND: RASopathies are a set of relatively common autosomal dominant clinically and genetically heterogeneous disorders. Cardiac outcomes in terms of mortality and morbidity for common heart defects (such as pulmonary valve stenosis and hypertrophic cardiomyopathy) have been reported. Nevertheless, also Atypical Cardiac Defects (ACDs) are described. The aim of the present study was to report both prevalence and cardiac outcome of ACDs in patients with RASopathies. METHODS: A retrospective, multicentric observational study (CArdiac Rasopathy NETwork-CARNET study) was carried out. Clinical, surgical, and genetic data of the patients who were followed until December 2019 were collected. RESULTS: Forty-five patients out of 440 followed in CARNET centers had ACDs. Noonan Syndrome (NS), NS Multiple Lentigines (NSML) and CardioFacioCutaneous Syndrome (CFCS) were present in 36, 5 and 4 patients, respectively. Median age at last follow-up was 20.1 years (range 6.9-47 years). Different ACDs were reported, including mitral and aortic valve dysfunction, ascending and descending aortic arch anomalies, coronary arteries dilation, enlargement of left atrial appendage and isolated pulmonary branches diseases. Five patients (11%) underwent cardiac surgery and one of them underwent a second intervention for mitral valve replacement and severe pericardial effusion. No patients died in our cohort until December 2019. CONCLUSIONS: Patients with RASopathies present a distinct CHD spectrum. Present data suggest that also ACDs must be carefully investigated for their possible impact on the clinical outcome. A careful longitudinal follow up until the individuals reach an adult age is recommended.


Subject(s)
Heart Defects, Congenital , Adolescent , Adult , Child , Ectodermal Dysplasia , Failure to Thrive , Humans , Middle Aged , Noonan Syndrome , Retrospective Studies , Young Adult , ras Proteins
11.
Ital J Pediatr ; 46(1): 61, 2020 May 13.
Article in English | MEDLINE | ID: mdl-32404184

ABSTRACT

Atrioventricular canal defect (AVCD) represents a quite common congenital heart defect (CHD) accounting for 7.4% of all cardiac malformations. AVCD is a very heterogeneous malformation that can occur as a phenotypical cardiac aspect in the context of different genetic syndromes but also as an isolated, non-syndromic cardiac defect. AVCD has also been described in several pedigrees suggesting a pattern of familiar recurrence. Targeted Next Generation Sequencing (NGS) techniques are proved to be a powerful tool to establish the molecular heterogeneity of AVCD.Given the complexity of cardiac embryology, it is not surprising that multiple genes deeply implicated in cardiogenesis have been described mutated in patients with AVCD. This review attempts to examine the recent advances in understanding the molecular basis of this complex CHD in the setting of genetic syndromes or in non-syndromic patients.


Subject(s)
Heart Septal Defects/diagnosis , Heart Septal Defects/genetics , Humans
12.
J Immunol Res ; 2020: 6937154, 2020.
Article in English | MEDLINE | ID: mdl-32280719

ABSTRACT

Down Syndrome (DS) is the most common chromosomal disorder. Although DS individuals are mostly perceived as characterized by some distinct physical features, cognitive disabilities, and cardiac defects, they also show important dysregulations of immune functions. While critical information is available for adults with DS, little literature is available on the neuroinflammation in prepubertal DS children. We aimed to evaluate in prepubertal DS children the serum levels of nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF), oxidative stress as free oxygen radicals defense (FORD), free oxygen radicals test (FORT), and cytokines playing key roles in neuroinflammation and oxidative processes as TNF-α, TGF-ß, MCP-1, IL-1α, IL-2, IL-6, IL-10, and IL-12. No differences were found in NGF between DS children and controls. However, BDNF was higher in DS subjects compared to controls. We also did not reveal changes in FORD and FORT. Quite interestingly, the serum of DS children disclosed a marked decrease in all analyzed cytokines with evident differences in serum cytokine presence between male and female DS children. In conclusion, the present study evidences in DS prepubertal children a disruption in the neurotrophins and immune system pathways.


Subject(s)
Biomarkers/blood , Brain-Derived Neurotrophic Factor/blood , Cytokines/blood , Down Syndrome/diagnosis , Neurogenic Inflammation/diagnosis , Child, Preschool , Down Syndrome/immunology , Female , Humans , Immune System , Male , Nerve Growth Factor/blood , Neurogenic Inflammation/immunology , Puberty , Reactive Oxygen Species/blood , Sex Factors , Signal Transduction
13.
Nat Ecol Evol ; 2(10): 1579-1587, 2018 10.
Article in English | MEDLINE | ID: mdl-30150740

ABSTRACT

A substantial body of evidence has demonstrated that biodiversity stabilizes ecosystem functioning over time in grassland ecosystems. However, the relative importance of different facets of biodiversity underlying the diversity-stability relationship remains unclear. Here we use data from 39 grassland biodiversity experiments and structural equation modelling to investigate the roles of species richness, phylogenetic diversity and both the diversity and community-weighted mean of functional traits representing the 'fast-slow' leaf economics spectrum in driving the diversity-stability relationship. We found that high species richness and phylogenetic diversity stabilize biomass production via enhanced asynchrony in the performance of co-occurring species. Contrary to expectations, low phylogenetic diversity enhances ecosystem stability directly, albeit weakly. While the diversity of fast-slow functional traits has a weak effect on ecosystem stability, communities dominated by slow species enhance ecosystem stability by increasing mean biomass production relative to the standard deviation of biomass over time. Our in-depth, integrative assessment of factors influencing the diversity-stability relationship demonstrates a more multicausal relationship than has been previously acknowledged.


Subject(s)
Biodiversity , Embryophyta , Grassland , Life History Traits , Biomass , Models, Biological , Phylogeny
14.
Data Brief ; 16: 649-654, 2018 Feb.
Article in English | MEDLINE | ID: mdl-29541661

ABSTRACT

A comprehensive description of morbidity and mortality in patients affected by mutations in genes encoding for signal transducers of the RAS-MAPK cascade (RASopathies) was performed in our study recently published in the International Journal of Cardiology. Seven European cardiac centres participating to the CArdiac Rasopathy NETwork (CARNET), collaborated in this multicentric, observational, retrospective data analysis and collection. In this study, clinical records of 371 patients with confirmed molecular diagnosis of RASopathy were reviewed. Cardiac defects, crude mortality, survival rate of patients with 1) hypertrophic cardiomyopathy (HCM) and age <2 years or young adults; 2) individuals with Noonan syndrome and pulmonary stenosis carrying PTPN11 mutations; 3) biventricular obstruction and PTPN11 mutations; 4) Costello syndrome or cardiofaciocutaneous syndrome were analysed. Mortality was described as crude mortality, cumulative survival and restricted estimated mean survival. In particular, with this Data In Brief (DIB) paper, the authors aim to report specific statistic highlights of the multivariable regression analysis that was used to assess the impact of mutated genes on number of interventions and overall prognosis.

15.
Int J Cardiol ; 245: 92-98, 2017 Oct 15.
Article in English | MEDLINE | ID: mdl-28768581

ABSTRACT

BACKGROUND: RASopathies are developmental disease caused by mutations in genes encoding for signal transducers of the RAS-MAPK cascade. The aim of the present study was to provide a comprehensive description of morbidity and mortality in patients with molecularly confirmed RASopathy. METHODS: A multicentric, observational, retrospective study was conducted in seven European cardiac centres participating to the CArdiac Rasopathy NETwork (CARNET). Clinical records of 371 patients with confirmed molecular diagnosis of RASopathy were reviewed. Mortality was described as crude mortality, cumulative survival and restricted estimated mean survival. Multivariable regression analysis was used to assess the impact of mutated genes on number of interventions and overall prognosis. RESULTS: Cardiac defects occurred in 80.3% of cases, almost half of them underwent at least one intervention. Overall, crude mortality was 0.29/100 patients-year. Cumulative survival was 98.8%, 98.2%, 97.7%, 94.3%, at 1, 5, 10, and 20years, respectively. Restricted estimated mean survival at 20years follow-up was 19.6years. Ten patients died (2.7% of the entire cohort; 3.4% of patients with cardiac defect). Patients with hypertrophic cardiomyopathy (HCM) and age <2years or young adults, as well as subjects with biventricular obstruction and PTPN11 mutations had a higher risk of cardiac death. CONCLUSIONS: The risk of intervention was higher in individuals with Noonan syndrome and pulmonary stenosis carrying PTPN11 mutations. Overall, mortality was relatively low, even though the specific association between HCM, biventricular outflow tract obstructions and PTPN11 mutations appeared to be associated with early mortality, including immediate post-operative events and sudden death.


Subject(s)
Heart Defects, Congenital/genetics , Heart Defects, Congenital/mortality , MAP Kinase Signaling System/genetics , Mutation/genetics , ras Proteins/genetics , Adolescent , Adult , Cardiomyopathy, Hypertrophic/genetics , Cardiomyopathy, Hypertrophic/mortality , Child , Child, Preschool , Female , Humans , Infant , Infant, Newborn , Middle Aged , Morbidity , Mortality/trends , Noonan Syndrome/genetics , Noonan Syndrome/mortality , Protein Tyrosine Phosphatase, Non-Receptor Type 11/genetics , Pulmonary Valve Stenosis/genetics , Pulmonary Valve Stenosis/mortality , Retrospective Studies , Young Adult
16.
BMC Ecol ; 16: 19, 2016 Apr 07.
Article in English | MEDLINE | ID: mdl-27056681

ABSTRACT

BACKGROUND: Several studies have examined the effects of plant colonization on aboveground communities and processes. However, the effects of plant colonization on soil microbial communities are less known. We addressed this gap by studying effects of plant colonization within an experimental plant diversity gradient in subplots that had not been weeded for 2 and 5 years. This study was part of a long-term grassland biodiversity experiment (Jena Experiment) with a gradient in plant species richness (1, 2, 4, 8, 16, and 60 sown species per plot). We measured plant species richness and productivity (aboveground cover and biomass) as well as soil microbial basal respiration and biomass in non-weeded subplots and compared the results with those of weeded subplots of the same plots. RESULTS: After 2 and 5 years of plant colonization, the number of colonizing plant species decreased with increasing plant diversity, i.e., low-diversity plant communities were most vulnerable to colonization. Plant colonization offset the significant relationship between sown plant diversity and plant biomass production. In line with plant community responses, soil basal respiration and microbial biomass increased with increasing sown plant diversity in weeded subplots, but soil microbial properties converged in non-weeded subplots and were not significantly affected by the initial plant species richness gradient. CONCLUSION: Colonizing plant species change the quantity and quality of inputs to the soil, thereby altering soil microbial properties. Thus, plant community convergence is likely to be rapidly followed by the convergence of microbial properties in the soil.


Subject(s)
Biodiversity , Plant Physiological Phenomena , Soil Microbiology , Species Specificity
17.
Article in English | MEDLINE | ID: mdl-27114579

ABSTRACT

Global change drivers are rapidly altering resource availability and biodiversity. While there is consensus that greater biodiversity increases the functioning of ecosystems, the extent to which biodiversity buffers ecosystem productivity in response to changes in resource availability remains unclear. We use data from 16 grassland experiments across North America and Europe that manipulated plant species richness and one of two essential resources-soil nutrients or water-to assess the direction and strength of the interaction between plant diversity and resource alteration on above-ground productivity and net biodiversity, complementarity, and selection effects. Despite strong increases in productivity with nutrient addition and decreases in productivity with drought, we found that resource alterations did not alter biodiversity-ecosystem functioning relationships. Our results suggest that these relationships are largely determined by increases in complementarity effects along plant species richness gradients. Although nutrient addition reduced complementarity effects at high diversity, this appears to be due to high biomass in monocultures under nutrient enrichment. Our results indicate that diversity and the complementarity of species are important regulators of grassland ecosystem productivity, regardless of changes in other drivers of ecosystem function.


Subject(s)
Biodiversity , Droughts , Eutrophication , Grassland , Plant Physiological Phenomena , Europe , North America
18.
Am J Med Genet A ; 170(3): 665-9, 2016 Mar.
Article in English | MEDLINE | ID: mdl-26686981

ABSTRACT

Noonan syndrome (NS) is the second most frequent hereditary syndrome with cardiac involvement. Pulmonary valve stenosis and hypertrophic cardiomyopathy are the most prevalent cardiovascular abnormalities. We report on a 14-year-old girl with NS due to SOS1 mutation with pulmonary stenosis and idiopathic coronary ectasia. To the best of our knowledge, this is the first report describing coronary ectasia in a patient with NS secondary to a SOS1 mutation. We include a literature review of this rare association.


Subject(s)
Cardiomyopathy, Hypertrophic/genetics , Coronary Artery Disease/genetics , Mutation , Noonan Syndrome/genetics , Pulmonary Valve Stenosis/genetics , SOS1 Protein/genetics , Adolescent , Cardiomyopathy, Hypertrophic/complications , Cardiomyopathy, Hypertrophic/diagnosis , Cardiomyopathy, Hypertrophic/pathology , Coronary Artery Disease/complications , Coronary Artery Disease/diagnosis , Coronary Artery Disease/pathology , Female , Gene Expression , Humans , Noonan Syndrome/complications , Noonan Syndrome/diagnosis , Noonan Syndrome/pathology , Pulmonary Valve Stenosis/complications , Pulmonary Valve Stenosis/diagnosis , Pulmonary Valve Stenosis/pathology
19.
Nature ; 526(7574): 574-7, 2015 Oct 22.
Article in English | MEDLINE | ID: mdl-26466564

ABSTRACT

It remains unclear whether biodiversity buffers ecosystems against climate extremes, which are becoming increasingly frequent worldwide. Early results suggested that the ecosystem productivity of diverse grassland plant communities was more resistant, changing less during drought, and more resilient, recovering more quickly after drought, than that of depauperate communities. However, subsequent experimental tests produced mixed results. Here we use data from 46 experiments that manipulated grassland plant diversity to test whether biodiversity provides resistance during and resilience after climate events. We show that biodiversity increased ecosystem resistance for a broad range of climate events, including wet or dry, moderate or extreme, and brief or prolonged events. Across all studies and climate events, the productivity of low-diversity communities with one or two species changed by approximately 50% during climate events, whereas that of high-diversity communities with 16-32 species was more resistant, changing by only approximately 25%. By a year after each climate event, ecosystem productivity had often fully recovered, or overshot, normal levels of productivity in both high- and low-diversity communities, leading to no detectable dependence of ecosystem resilience on biodiversity. Our results suggest that biodiversity mainly stabilizes ecosystem productivity, and productivity-dependent ecosystem services, by increasing resistance to climate events. Anthropogenic environmental changes that drive biodiversity loss thus seem likely to decrease ecosystem stability, and restoration of biodiversity to increase it, mainly by changing the resistance of ecosystem productivity to climate events.


Subject(s)
Biodiversity , Climate , Ecosystem , Plant Physiological Phenomena , Climate Change/statistics & numerical data , Conservation of Natural Resources , Disasters/statistics & numerical data , Droughts , Grassland , Human Activities
20.
Oecologia ; 174(1): 183-93, 2014 Jan.
Article in English | MEDLINE | ID: mdl-23907703

ABSTRACT

Plant diversity is a key driver of ecosystem functioning best documented for its influence on plant productivity. The strength and direction of plant diversity effects on species interactions across trophic levels are less clear. For example, with respect to the interactions between herbivorous invertebrates and plants, a number of competing hypotheses have been proposed that predict either increasing or decreasing community herbivory with increasing plant species richness. We investigated foliar herbivory rates and consumed leaf biomass along an experimental grassland plant diversity gradient in year eight after establishment. The gradient ranged from one to 60 plant species and manipulated also functional group richness (from one to four functional groups-legumes, grasses, small herbs, and tall herbs) and plant community composition. Measurements in monocultures of each plant species showed that functional groups differed in the quantity and quality of herbivory damage they experienced, with legumes being more damaged than grasses or non-legume herbs. In mixed plant communities, herbivory increased with plant diversity and the presence of two key plant functional groups in mixtures had a positive (legumes) and a negative (grasses) effect on levels of herbivory. Further, plant community biomass had a strong positive impact on consumed leaf biomass, but little effect on herbivory rates. Our results contribute detailed data from a well-established biodiversity experiment to a growing body of evidence suggesting that an increase of herbivory with increasing plant diversity is the rule rather than an exception. Considering documented effects of herbivory on other ecosystem functions and the increase of herbivory with plant diversity, levels of herbivory damage might not only be a result, but also a trigger within the diversity-productivity relationship.


Subject(s)
Biodiversity , Fabaceae , Herbivory , Invertebrates/physiology , Poaceae , Animals , Biomass , Ecosystem , Germany , Plant Leaves
SELECTION OF CITATIONS
SEARCH DETAIL
...