Plant reproductive success in highly fragmented Valais vineyard landscapes: a quasi-experimental approach

The ongoing intensification of agriculture has led to habitat loss, degradation and fragmentation with their concomitant negative effects on biodiversity. For plant populations relying on pollinators those processes are expected to have severe effects on individual fitness due to limited pollinator numbers or reduced accessibility in isolated habitat patches. Intensively managed vineyards represent an ideal study system due to their near-binary habitats (vineyards with and without ground vegetation) and their high variation in habitat configuration on a landscape-scale. Here we investigated the effects of habitat quality and the degree of habitat fragmentation on fitness-related variables in four plant species (Lotus corniculatus, Trifolium pratense, Centaurea jacea and Sinapis alba) and the relationships with pollinator abundance. Habitat quality, i.e. the amount of ground vegetation significantly affected pollinator visitation rate and reproductive success of plants. Interestingly, habitat amount and the degree of fragmentation had no detectable effects on plant reproductive success, most likely due to the high mobility of pollinator species. Overall these results indicate that the reproductive success of a plant is mainly determined by local habitat quality, i.e. the local management of a vineyard, and to a lower degree by factors acting on the landscape scale.peerReviewe

Effects of habitat fragmentation on bumblebee foraging trip duration and colony fitness

Agricultural intensification with the associated habitat loss and fragmentation are among the most important drivers for the dramatic loss of wild pollinators. In this study, conducted in intensively managed vineyards in southern Switzerland, we tested the interdependent effects of habitat amount (surface of vegetated vineyards per landscape) and fragmentation (number of vegetated vineyards per landscape) on fitness-relevant traits in bumblebee Bombus terrestris terrestris colonies. Individual bumblebee foraging trips were measured with RFID (radio frequency identification) technology while colony fitness was assessed by quantifying nest parameters related to colony size. Vegetation cover in vineyards showed an overall positive effect on colony fitness and foraging behaviour. More specifically, colony fitness was strongly driven by an interactive effect of habitat amount and fragmentation: the degree of fragmentation had a negative effect on bumblebee colony fitness when the amount of habitat was low, while it positively affected colony fitness in landscapes with high amounts of habitat. These results highlight the interdependency of habitat amount and fragmentation on a pollinator’s fitness with its concomitant consequences on management recommendations. Whenever habitat amount is low the surface of vegetated vineyards should be increased and aggregated whereas mosaic-like habitats composed of different management styles should be created when habitat amount is high.peerReviewe

Smaller brain volumes at two years of age in patients with hypoplastic left heart syndrome - Impact of surgical approach

BACKGROUND Brain growth in hypoplastic left heart syndrome (HLHS) is reduced before and after birth. Little is known about further brain growth until two years of age before Fontan procedure and the potential impact of type of surgery. METHODS In a prospective, two-center study 29 patients with HLHS and variants were treated by Norwood (n = 5) or Hybrid procedure (n = 24). At two years of age a cerebral MRI was performed and brain volumes (total gray, deep gray, white matter) and cerebrospinal fluid volume were calculated using FreeSurfer image analysis suite and compared to a healthy control group (n = 8). RESULTS The total brain volumes in patients with HLHS were smaller compared to controls (HLHS: 893 ± 76 ml vs. controls: 1015 ± 148 ml, p = 0.005). This difference was found in all three brain compartments after Norwood procedure, whereas patients after Hybrid procedure had total and deep gray volumes comparable to controls. When comparing Norwood to Hybrid patients, deep gray matter volume reduction was more pronounced (Norwood: 38.4 ± 4.1 ml vs. Hybrid: 44.4 ± 3.9 ml, p = 0.005) than white matter reduction (Norwood: 255 ± 19 ml vs. Hybrid: 285 ± 31 ml, p = 0.032). CONCLUSIONS Smaller total and regional brain volumes were found two years after Norwood or Hybrid procedure in children with HLHS. The brain volume reduction was more distinct after Norwood than after Hybrid procedure. Longitudinal studies are needed to identify impact of early staged-surgeries on brain development and may become part of the decision-making process in individual patients

Neurodevelopmental Outcome and Health-related Quality of Life in Children With Single-ventricle Heart Disease Before Fontan Procedure

Neurodevelopmental impairment and impaired quality of life constitute a major source of morbidity among children with complex congenital heart disease, in particular for single-ventricle (SV) morphologies. Risk factors and quality of life determining clinical and neurodevelopmental outcome at 2 years of age are examined. In a 2-center cohort study, 48 patients with SV morphology (26 hypoplastic left heart syndrome and 22 other types of univentricular heart defect) have been examined before Fontan procedure between 2010 and 2015. Patients were assessed with the Bayley Scales of Infant and Toddler Development, Third Version (Bayley-III), and the Preschool Children Quality of Life (TAPQOL) questionnaire. A total of 44 patients underwent hybrid procedure (n = 25), Norwood procedure (n = 7), or shunt or banding procedure (n = 12) as first surgery before subsequent bidirectional cavopulmonary anastomosis (n = 48). Median cognitive, language, and motor composite scores on the Bayley-III were 100 (range 65-120), 97 (68-124), and 97 (55-124), respectively. The language composite score was significantly below the norm (P = 0.025). Risk factors for poorer neurodevelopmental outcome were prolonged mechanical ventilation, longer days of hospital stay, and more reinterventions (all P < 0.05). Parents reported a good quality of life for their children. Children undergoing Fontan procedure show a favorable development and good quality of life. More complicated postoperative course and reinterventions constitute risk factors for impaired neurodevelopment. Improving postoperative management and implementing routine follow-up assessments aremeasures to further improve the neurodevelopmental outcome of this high-risk patient population

Reduction of brain volumes after neonatal cardiopulmonary bypass surgery in single ventricle congenital heart disease prior to Fontan completion

BACKGROUND: Little is known about the relationship between brain volumes and neurodevelopmental outcome at two years of age in children with single ventricle congenital heart disease (CHD). We hypothesized that reduced brain volumes may be associated with adverse neurodevelopmental outcome. METHODS: Volumetric segmentation of cerebral MRI scans was done in 44 patients without genetic comorbidities and in eight controls. Neurodevelopmental outcome was assessed with the Bayley-III scales. RESULTS: Gray matter (GM), deep GM, white matter (WM), and cerebrospinal fluid (CSF) volumes were 611±59 ml, 43±4.5 ml, 277±30 ml, and 16.4 ml (IQR 13.1, 23.3 ml). Children undergoing neonatal cardiopulmonary bypass surgery showed smaller deep GM (P=0.005) and WM (P=0.021) volumes. Brain volumes were smaller in patients compared to controls (GM: P=0.017, deep GM: P=0.012, WM: P=0.015), whereas CSF volumes were greater (P=0.014). Of all intracranial volumes, only CSF volume was associated with neurodevelopmental outcome, accounting for 21% (P=0.011) of variability in the cognitive composite score when combined with common risk factors in a multivariable analysis. CONCLUSION: Increased CSF volume represents a significant risk factor for neurodevelopmental impairment in children with single ventricle CHD. Later assessments are warranted to determine the prognostic role of intracranial volumes for long-term outcome.Pediatric Research accepted article preview online, 21 August 2017. doi:10.1038/pr.2017.203

Interrelationship between hemodynamics, brain volumes and outcome in Hypoplastic Left Heart Syndrome

BACKGROUND The long-term impact of altered hemodynamics after Stage II in children with hypoplastic left heart syndrome (HLHS) and hypoplastic left heart complex (HLHC) on cerebral growth and neurodevelopmental outcome is unknown. We aimed to investigate whether elevated central venous and atrial filling pressures before Fontan procedure may be associated with smaller brain volumes and poorer neurodevelopmental outcome after initial Hybrid procedure. METHODS In a two-center cohort study semi-automated segmentation of cerebral MRI scans was conducted in 25 children with HLHS/HLHC (25 Hybrid) before Fontan procedure (27.6 ± 4.3 months) and in 8 healthy controls (29.7 ± 9.5 months). Study patients were evaluated with the Bayley Scales of Infant and Toddler Development III (Bayley-III) and a neurological examination. Hemodynamic measures after Stage II were assessed with cardiac catheterization at two years of age before Fontan completion. Children with known genetic comorbidities were excluded. RESULTS In HLHS/HLHC patients, higher atrial filling pressures (6 ± 3 mmHg, range 2-14 mmHg) were correlated with reduced brain volumes and lower language composite score, while higher Glenn pressures (10 ± 3 mmHg, range 6-16 mmHg) were related to higher cerebrospinal fluid, reduced brain volumes and lower cognitive, language, and motoric composite scores in the Bayley-III. Compared to controls, white matter volumes were reduced, and cerebrospinal fluid volumes were increased in study patients. CONCLUSIONS These data suggest that altered cardiovascular hemodynamics after stage II influence brain growth and neurodevelopmental outcome in infants with HLHS/HLHC