An approximation of flights, delays and costs for different forecast scenarios: A backcasting exercise

Air Navigation Service Providers (ANSPs) play a critical role as a natural monopoly within the air traffic system and are subject to regulation. Achieving preset performance targets necessitates efficient resource planning, contingent upon accurate traffic forecasts. This means that forecast precision is a key determinant of operational efficiency. In this study, we employ backcasting techniques to gauge the influence of forecast errors on air traffic management performance. This is done for eleven airspaces and seven years of data. The paper seeks to estimate the cost of delays if the actual number of flights for the period 2015-2020 had been as predicted by EUROCONTROL through its specialised service STATFOR. To assess the impact of forecasting errors, we analyse the discrepancy between the predicted and actual figures for flight data, specifically focusing on delays. Our results show that forecast errors have a noteworthy, adverse effect on performance. Inaccurate predictions prevent efficient resource allocation. We prove that a marginal increase in forecast quality would significantly reduce overall costs for stakeholders.

Anxiety is the cause of the worse outcomes of allergic patients after total knee arthroplasty

PURPOSE

The presence of allergies has been proposed as a risk factor for worse outcomes in total knee arthroplasty surgery. The aim of this study is to evaluate if the presence of some psychiatric disorders is more frequent in patients who report allergies and if they could be the main cause for the worse outcomes.

METHODS

A prospective study, including patients undergoing a primary total knee arthroplasty, was designed. In the preoperative visit, all the patients completed a questionnaire about the presence of allergies and also psychiatric tests for anxiety (State-Trait Anxiety Inventory-STAI-), depression (Remission from Depression Questionnaire-RDQ-), somatization disorder (Patient Health Questionnaire-15-PHQ-15-), pain catastrophizing syndrome (Pain Catastrophizing Scale-PCS), and personality disorder (Reduced NEO-Inventory of Five Factors-NEO-FFI-). In the preoperative and at 6 months of follow up, the functional results of the surgery were assessed by the WOMAC, the SF-12, and the KSS scores.

RESULTS

A total of 209 patients was included: 136 (65%) did not have reported allergies and 73 (35%) did report some allergies. The psychiatric questionnaires showed that the presence of anxiety was more prevalent in the group of patients with reported allergies (STAI-T: no allergies 24.08 points vs. allergies 19.18 points, p = 0.039). When comparing the functional outcomes at 6 months of follow up, most of the analyzed scores improved less in the group of patients with reported allergies than in the no allergy-referred group: WOMAC-total score (34.37 vs. 40.10 points, p = 0.023), WOMAC-pain score (6.03 vs. 7.50 points, p = 0.018), WOMAC-function score (22.97 vs. 27.24 points, p = 0.023), KSS-knee score (25.37 vs. 33.79 points, p = 0.002), and SF-12 physical score (7.89 vs. 11.15 points, p = 0.046). The significance of the difference in the outcomes scores in this group was lost after adjusting for anxiety (p > 0.05).

CONCLUSION

Allergies reported by patients are confirmed as a risk factor for worse results after TKA surgery. The relationship with anxiety disorder seems to explain the association between self-reported allergies and sub-optimal outcomes.

LEVEL OF EVIDENCE

II.

Growth, photosynthetic acclimation and yield quality in legumes under climate change simulations: an updated survey

Continued emissions of CO2, derived from human activities, increase atmospheric CO2 concentration. The CO2 rise stimulates plant growth and affects yield quality. Effects of elevated CO2 on legume quality depend on interactions with N2-fixing bacteria and mycorrhizal fungi. Growth at elevated CO2 increases photosynthesis under short-term exposures in C3 species. Under long-term exposures, however, plants generally acclimate to elevated CO2 decreasing their photosynthetic capacity. An updated survey of the literature indicates that a key factor, perhaps the most important, that characteristically influences this phenomenon, its occurrence and extent, is the plant source-sink balance. In legumes, the ability of exchanging C for N at nodule level with the N2-fixing symbionts creates an extra C sink that avoids the occurrence of photosynthetic acclimation. Arbuscular mycorrhizal fungi colonizing roots may also result in increased C sink, preventing photosynthetic acclimation. Defoliation (Anthyllis vulneraria, simulated grazing) or shoot cutting (alfalfa, usual management as forage) largely increases root/shoot ratio. During re-growth at elevated CO2, new shoots growth and nodule respiration function as strong C sinks that counteracts photosynthetic acclimation. In the presence of some limiting factor, the legumes response to elevated CO2 is weakened showing photosynthetic acclimation. This survey has identified limiting factors that include an insufficient N supply from bacterial strains, nutrient-poor soils, low P supply, excess temperature affecting photosynthesis and/or nodule activity, a genetically determined low nodulation capacity, an inability of species or varieties to increase growth (and therefore C sink) at elevated CO2 and a plant phenological state or season when plant growth is stopped.

Methodological advances: using greenhouses to simulate climate change scenarios

Human activities are increasing atmospheric CO2 concentration and temperature. Related to this global warming, periods of low water availability are also expected to increase. Thus, CO2 concentration, temperature and water availability are three of the main factors related to climate change that potentially may influence crops and ecosystems. In this report, we describe the use of growth chamber - greenhouses (GCG) and temperature gradient greenhouses (TGG) to simulate climate change scenarios and to investigate possible plant responses. In the GCG, CO2 concentration, temperature and water availability are set to act simultaneously, enabling comparison of a current situation with a future one. Other characteristics of the GCG are a relative large space of work, fine control of the relative humidity, plant fertirrigation and the possibility of light supplementation, within the photosynthetic active radiation (PAR) region and/or with ultraviolet-B (UV-B) light. In the TGG, the three above-mentioned factors can act independently or in interaction, enabling more mechanistic studies aimed to elucidate the limiting factor(s) responsible for a given plant response. Examples of experiments, including some aimed to study photosynthetic acclimation, a phenomenon that leads to decreased photosynthetic capacity under long-term exposures to elevated CO2, using GCG and TGG are reported.

Effect of psychiatric liaison nurse specialist consultation on the care of medical-surgical patients with sitters

One hundred seven patients in an acute care setting who had lay sitters to provide the constant observation judged necessary to meet their safety needs were studied to determine the effect of psychiatric liaison nurse specialist (PLNS) consultation on nursing care and the use of sitters. After placement in either a suicidal or nonsuicidal group, subjects were randomly assigned to receive consultation or not. Outcome variables of number of sitter shifts, number of nursing note observations, number of patient and sitter incidents and length of hospital stay were considered. Multiple analysis of variance indicated no significant differences among the groups for number of sitter shifts or number of nursing note observations. A significant main effect for group on length of hospital stay was found with suicidal patients having a significantly shorter hospital stay. Number of patients and sitter incidents were too small for analysis.

Characteristics of patients with the highest plasma catecholamine metabolite levels

The authors measured plasma levels of free homovanillic acid (HVA) and 3-methoxy-4-hydroxyphenyl-glycol (MHPG) in 350 consecutive psychiatric patients. Among the 22 patients with the highest values for both HVA and MHPG, the primary diagnoses were psychotic disorders, eating disorders, and major depression.

Correlates of early neuroleptic response using a uniform haloperidol dose

Twenty-one patients hospitalized for acute non-organic psychosis were treated with a fixed daily dose of haloperidol (0.2 mg/kg) for 10 days. Serum levels of haloperidol were significantly lower in the male patients at steady state as compared to females. Serum levels at 24 h and 48 h were highly correlated steady-state levels. Haloperidol levels at steady state were significantly correlated with global outcome at 10 days. Prolactin at haloperidol steady state was significantly related to global outcome at 10 days in the males. Pretreatment plasma free HVA but not MHPG was significantly related to outcome in males and females.

Early neuroleptic response: clinical profiles and plasma catecholamine metabolites

Forty-seven psychotic inpatients who required neuroleptic treatment were studied with respect to some clinical and biochemical variables associated with early neuroleptic response. Compared to poor early responders, good responders were older at onset of illness and at index admission, less likely to have had a schizoid developmental history, and more likely to be married. There was a trend for good early responders to have received a diagnosis of affective psychosis or atypical psychotic disorder rather than schizophrenia or schizophreniform disorder. However, no behavioral symptom or sign differentiated good from poor early responders with the possible exception of pretreatment psychomotor retardation, which showed some association with poor response. Fasting plasma-free homovanillic acid was significantly higher in the good response group and 3-methoxy-4-hydroxyphenethylene glycol showed a similar trend.

Ratio of serum prolactin to haloperidol and early clinical outcome in acute psychosis

The ratio of the increase in serum prolactin concentration to steady-state haloperidol concentration in acutely psychotic women correlated with early clinical improvement. Correction of prolactin response for neuroleptic concentration may provide a better clinical predictor than either measure alone.

Plasma catecholamine metabolites and early response to haloperidol

Plasma homovanillic acid (HVA) and methoxyhydroxyphenyl glycol (MHPG) as well as serum haloperidol and prolactin were measured in patients admitted to a general hospital psychiatric service for treatment of acute psychosis. At 10 days, good responders compared to poor responders had higher mean plasma HVA values before and during the first week of treatment with 0.2-0.4 mg/kg haloperidol per day. MHPG values showed a similar pattern, although no significant differences were obtained between or within the two groups. Females predominated among good responders; neither DSM-III diagnoses nor steady state haloperidol levels differed significantly between the two groups. Significant correlations within some patients were obtained between prolactin and haloperidol (positive), prolactin and MHPG (negative), and HVA and MHPG (positive). Plasma catecholamine metabolites deserve further study as possible markers of early response to the treatment of acute psychosis with modest doses of neuroleptic drugs.