Wildfires shape the composition and functioning of Mediterranean ecosystems, but we do not know how these ecosystems respond to both the higher fire recurrence and shorter recovery times expected for ...future climatic scenarios. We sampled 29 plots with different fire recurrences (from 0 to 4 fires over the past decades) and time since the last fire (up to 35 years; hereafter TSLF) in Southeast Spain, to assess the effect of fire recurrence and TSLF on 25 ecosystem attributes, five related ecosystem services (biodiversity conservation, carbon sequestration, disturbance regulation, food production, and supporting services), plus the synergies and trade-offs between them. High fire recurrence (number of fires) and TSLF interacted to determine ecosystem services but did not affect the synergies and trade-offs between them. Fire recurrence reduced many ecosystem functions and ecosystem multifunctionality. However, this effect dampened, and even became positive, for biodiversity conservation and food production services provided enough (> 20 years) time to recover. The combined effects of fire recurrence and TSLF, however, reduced carbon sequestration and had no overall effects on supporting services. Disturbance regulation, in turn, diminished drastically with the first fire, with no effect of further fires or their interaction with TSLF. Our results show which ecosystem services will suffer more from an increase in fire recurrence, and where restoration and management efforts should focus to maximize the provision of those services more demanded by stakeholders.
Post-fire regeneration in Pinus halepensis' forests, one of the most abundant vegetation types in the Mediterranean basin, often generates overstocked and vulnerable stands. They accumulate a high ...fuel load, increasing the risk of further fires, and present high levels of vulnerability due to their reduced seed production. In addition, these dense stands substantially reduce the availability of light and nutrients, which may hinder the recruitment of other species, often generating mono-specific and homogeneous stands, which potentially supply fewer ecosystem services than mixed forests with more heterogeneous structures. In these dense pine stands, management is of high priority to reduce fire hazards and promote their functionality. In overstocked pine stands (>75,000 trees·ha−1), we assessed the long-term effects (10 years) of two thinning levels (600 and 1200 trees·ha−1), in combination with the plantation of Quercus faginea (a resprouter species typical of advanced successional stages in our study area) on 28 above and belowground ecosystem attributes, including fire hazard. After ten years, thinning and plantation interacted to enhance ecosystem attributes associated with disturbance regulation and biodiversity conservation (up to 200%) and food production (up to 90%), while no effects were observed on those attributes related to carbon sequestration and supporting services. These effects were mainly driven by aboveground attributes, as they responded more strongly to our treatments than those belowground. Our results are relevant for the restoration of Mediterranean degraded ecosystems, and show that tree thinning in overstocked pine stands, combined with the plantation of resprouter species, may not only reduce fire risks and accelerate post-fire succession but also enhance the supply of multiple ecosystem services in the long run.
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•The combination of thinning and resprouter plantation improved ecosystem functions.•Moderate thinning suffices to enhance individual aboveground attributes.•Plantation of resprouter species helps to maximize ecosystem services.•Ecosystem responses to management are driven by aboveground but not belowground attributes.
Changes in climate and land use are altering fire regimes in many regions across the globe. This work aims to study the influence of wildfire recurrence and burn severity on woody community structure ...and plant functional traits under different environmental conditions. We selected three study sites along a Mediterranean-Oceanic climatic gradient, where we studied the fire history and burn severity of the last wildfire. Four years after the last wildfire, we established 1776 1-m2 plots where the percentage cover of each woody species was sampled. We calculated (i) structural parameters of the community such as total cover, alpha species richness, evenness and diversity (Shannon diversity index), and (ii) vegetation cover of each functional group (differentiating life forms, eco-physiological traits and regenerative traits). Focusing on community structure, results showed increases in species richness and diversity as wildfire recurrence increased, but this effect was partially counterweighted in the areas affected by high severity. In relation to functional groups, we found that increases in recurrence and severity fostered transition from tree- to shrub-dominated ecosystems. Non-arboreal life form, high specific leaf area, N2-fixing capacity, resprouting ability and heat-stimulated germination were advantageous traits under high recurrences and severities, and low seed mass was advantageous under high recurrence situations. We suggest that the strength of the effects of wildfire recurrence and burn severity on vegetation structure and traits might vary with climate, increasing from Oceanic to Mediterranean conditions. In the Mediterranean site, recurrence and severity were strongly related to traits associated with germination (seed mass and heat-stimulated germination), whereas in the Oceanic site the strongest relationships were found with a resprouting-related trait (bud location). This study identifies changes in vegetation structure and composition in scenarios of high recurrence and severity, and provides useful information on plant traits that could be key in enhancing vegetation resilience.
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•Wildfire recurrence and burn severity modify plant species richness and diversity.•High recurrence and severity fosters transition from forests to shrublands.•Several plant traits are advantageous in fire regimes of high recurrence and severity.•Fire recurrence and severity effects on vegetation may vary with climatic conditions.
Background
Disturbance-regime shifts are often a manifestation related to climate change. In Mediterranean ecosystems, summer-drought lengthening and high fire-severity may be among the most ...detrimental processes for plant recovery capacity. However, although isolated effects have been usually assessed, the effects when both disturbances interact are less known. This paper examined the possible interactive impacts of increased fire severity and summer-drought lengthening on Mediterranean vegetation recovery. Our initial hypothesis maintained that both disturbances would interact and cause greater recovery damage than in an isolated way. For this reason, we performed an experimental fire in summer by creating two fire severity levels: control fire severity (CSev) and increased fire severity by adding dry biomass (IncrSev). Following fire, and using rainfall exclusions roofs, we extended summer drought conditions toward the first autumn after fire (AutExcl treatment) and toward the first post-fire spring (SprExcl). All the treatment-levels combinations were replicated in five 0.5 × 0.5 m plots.
Results
Emerged seedlings were not affected by treatments, but plant establishment was significantly impaired by extended droughts at the end of the first post-fire year, particularly for Cistaceae and subshrubs. Nevertheless, we found no effects of increased fire severity on either isolation or combination with drought. Notwithstanding, the combination of some treatment levels brought about changes in plant composition. These changes were driven mainly by the detrimental effects of treatments on perennial forbs. This functional group was affected by treatments, which suggests that they may be more sensitive to changes in fire severity and severe droughts.
Conclusion
Increased fire severity might not affect plant recovery either by itself or by interacting with drought because prolonged drought may mask increased fire severity impact on Mediterranean seeding species. However, fire-severity increases, together with sporadic drought events in the early stages of these communities, could imply long-lasting changes in community composition due to distinct functional-groups sensitivities. Nevertheless, these impacts depend on the considered species or functional group. These findings provide information about the impacts that Mediterranean-shrublands ecosystems might face if the trends of fire and drought regimes continue shifting.
Background
There is a clear predominance of programmes aimed at improving aspects related to language production in pupils with developmental language disorder (DLD). However, programmes aimed at ...improving their receptive skills are limited.
Aims
The main aim was to assess the effectiveness of an intervention programme for oral language comprehension skills in preschoolers with typical development (TD) and pupils with DLD.
Methods & Procedures
Participants were 99 five‐year‐old pupils, with and without DLD, divided into four groups: two control groups (TD‐C = 25; DLD‐C = 25) and two experimental groups (TD‐T = 24; DLD‐T = 25), from schools on the Spanish island of Tenerife. The study used, as pre‐ and post‐measures, the receptive language subtests of the CELF‐4‐Spanish: Concepts and Following Directions, Word Classes—Receptive and Sentence Structure, as well as two tasks assessing comprehension of paragraphs and narratives. Due to the strong link between oral comprehension skills and executive functions, working memory and semantic fluency are included in this research. The Backward Digit Span subtest of the Wechsler Intelligence Scale for Children (WISC‐IV) and Semantic Fluency subtest of the Controlled Oral Word Association Test (COWAT) were used to assess working memory and semantic fluency, respectively. The intervention programme followed a multitiered system of support (MTSS) model, with 95 sessions lasting 60 min each delivered jointly by teachers and speech and language therapists, and focused on lexical–semantic, morphological, syntactic and narrative skills; inferences; verbal working memory; and semantic fluency.
Outcomes & Results
The results showed, as expected, that pupils diagnosed with DLD initially performed worse on oral language comprehension and executive functions than pupils with TD. Further, the DLD‐T and TD‐T groups showed greater gains following the programme, especially in word classes—receptive, sentence structure, verbal working memory and semantic fluency. Finally, a significant positive correlation was found between the gains obtained by the participants in verbal working memory and semantic fluency, with the gains obtained in the three CELF‐4‐Spanish subtests.
Conclusions & Implications
An intervention programme applied at an early age fosters oral language comprehension skills and executive functions in pupils with DLD and TD. The intervention organized at different levels of support, following an MTSS model, showed clear progress of the DLD and TD groups in oral language comprehension and executive functions.
What this paper adds
Pupils with DLD present deficits in linguistic comprehension and executive functions. There are many intervention programs focused on improving language production skills. It is also necessary to consider the skills underlying language problems in pupils with DLD. Oral language, inference, working memory and semantic fluency activities improve comprehension. A collaborative and inclusive intervention of teachers and speech language therapists. Psycholinguistic and neuropsychological skills training should become part of the academic curriculum as early as preschool age.
What is already known on the subject
Pupils with DLD show problems related to both comprehension and production language. However, there is a clear predominance of programs just aimed at improving aspects related to language production.
Clinical implications of this study
An intervention program applied at an early age fosters oral language comprehension skills and executive function in pupils with DLD. The intervention organized at different levels of support, following an adaptation of the Response Tier Intervention models, showed clear progress of the DLD in comprehension oral language and executive functions.
Introduction
Major advances in the field of pediatric oncology have resulted from rigorous, prospective clinical oncology research trials. Optimizing access for all children and adolescents to ...clinical research trials is an important goal. Barriers to clinical trial enrollment are numerous, involving the health care system, research infrastructure, access to care, providers, and participants. The perspectives of pediatric oncologists may provide insight into the barriers of clinical trial enrollment for this unique population.
Methods and materials
We conducted qualitative structured interviews over two months of pediatric oncologists in a community‐based clinical network as part of a quality improvement project aimed at increasing enrollment rates at St. Jude Affiliate Clinics. We assessed barriers and facilitators to clinical trial opportunities for racial and ethnic minority pediatric participants. In the same fiscal year of the interviews, we tracked clinical trial enrollment by race and ethnicity of the participant over 12 months.
Results
The major barriers to clinical trial enrollment for pediatric cancer minority participants included language discordance, travel difficulties, and complex trial designs. In contrast, the major facilitators included building trust with participants and their parents, and education on the merits of clinical research studies. We did not observe any disparities in clinical trial enrollment among the racial and ethnic minority participants of the clinical trials conducted across our network of pediatric oncology clinics.
Conclusions
Identifying barriers and facilitators may improve clinical trial enrollment for underrepresented participant groups.
Anti-GD2 mAbs, acting via antibody-dependent cell-mediated cytotoxicity, may enhance the effects of chemotherapy. This pilot trial investigated a fixed dose of a unique anti-GD2 mAb, hu14.18K322A, ...combined with chemotherapy, cytokines, and haploidentical natural killer (NK) cells.
Children with recurrent/refractory neuroblastoma received up to six courses of hu14.18K322A (40 mg/m
/dose, days 2-5), GM-CSF, and IL2 with chemotherapy: cyclophosphamide/topotecan (courses 1,2), irinotecan/temozolomide (courses 3,4), and ifosfamide/carboplatin/etoposide (courses 5,6). Parentally derived NK cells were administered with courses 2, 4, and 6. Serum for pharmacokinetic studies of hu14.18K322A, soluble IL2 receptor alpha (sIL2Rα) levels, and human antihuman antibodies (HAHA) were obtained.
Thirteen heavily pretreated patients (9 with prior anti-GD2 therapy) completed 65 courses. One patient developed an unacceptable toxicity (grade 4 thrombocytopenia >35 days). Four patients discontinued treatment for adverse events (hu14.18K322A allergic reaction, viral infection, surgical death, second malignancy). Common toxicities included grade 3/4 myelosuppression (13/13 patients) and grade 1/2 pain (13/13 patients). Eleven patients received 29 NK-cell infusions. The response rate was 61.5% (4 complete responses, 1 very good partial response, 3 partial responses) and five had stable disease. The median time to progression was 274 days (range, 239-568 days); 10 of 13 patients (77%) survived 1 year. Hu14.18K322A pharmacokinetics was not affected by chemotherapy or HAHA. All patients had increased sIL2Rα levels, indicating immune activation.
Chemotherapy plus hu14.18K322A, cytokines, and NK cells is feasible and resulted in clinically meaningful responses in patients with refractory/recurrent neuroblastoma. Further studies of this approach are warranted in patients with relapsed and newly diagnosed neuroblastoma.
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Biodiversity can increase in both high‐ and low‐connected landscapes. However, we lack predictions related to biodiversity dynamics when accounting for the temporal heterogeneity in the connections ...among the habitats of a landscape. Here, we study the relationship between fluctuations in landscape connectivity and biodiversity dynamics at local and regional scales. We contrast predictions about species richness between landscapes with and without fluctuations in connectivity. Our results show that local (α) and regional (γ) richness can increase together in dynamic landscapes characterized by periodic connectivity, clarifying empirical findings of high biodiversity in both low and high‐connected landscapes. Our results also suggest that fluctuations in connectivity increase the overall number of species coexisting in dynamic landscapes when compared with static landscapes with no fluctuations in connectivity. Extending metacommunity theory, by including fluctuations in landscape connectivity, can thus provide new testable predictions about species diversity across broad spatiotemporal scales in rapidly changing landscapes.
Increased vascular endothelial growth factor (VEGF) expression in osteosarcoma correlates with a poor outcome. We conducted a phase II trial to evaluate the feasibility and efficacy of combining ...bevacizumab, a monoclonal antibody against VEGF, with methotrexate, doxorubicin and cisplatin (MAP) in patients with localized osteosarcoma. Eligible patients received two courses of MAP chemotherapy before definitive surgery at week 10. Bevacizumab (15 mg/kg) was administered 3 days before starting chemotherapy then on day 1 of weeks 3 and 5 of chemotherapy. After surgery, patients received MAP for a total of 29 weeks; bevacizumab was added every 2 or 3 weeks on day 1 of chemotherapy at least 5 weeks after surgery. Group sequential monitoring rules were used to monitor for unacceptable bevacizumab-related targeted toxicity (grade 4 hypertension, proteinuria or bleeding, grade 3 or 4 thrombosis/embolism, and grade 2-4 major wound complications). Thirty-one patients (median age 12.8 years) with localized osteosarcoma were enrolled. No unacceptable targeted toxicities were observed except for wound complications (9 minor and 6 major), which occurred in 15 patients; none required removal of prosthetic hardware or amputation. The estimated 4-year event-free survival (EFS) rate and overall survival rate were 57.5 ± 10.0% and 83.4 ± 7.8%, respectively. Eight (28%) of 29 evaluable patients had good histologic response (<5% viable tumor) to preoperative chemotherapy. The addition of bevacizumab to MAP for localized osteosarcoma is feasible but frequent wound complications are encountered. The observed histologic response and EFS do not support further evaluation of bevacizumab in osteosarcoma.
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