Reproductive parameters of a new biocontrol agent, Eupeodes americanus (Diptera: Syrphidae) and comparison with the commercialized Aphidoletes aphidimyza (Diptera: Cecidomyiidae).

The American hoverfly Eupeodes americanus (Wiedemann) (Diptera: Syrphidae) is an aphidophagous predator during its larval stage and is currently being evaluated for inclusion in biocontrol programs as a new biocontrol agent. However, little is known about its reproductive aptitudes. The objective of the present study was to determine the reproductive parameters of E. americanus and to compare them with those of a commercialized and widely used biological control agent for aphids, the aphid midge Aphidoletes aphidimyza (Rondani) (Diptera: Cecidomyiidae). The preoviposition period, oviposition period, adult longevity, lifetime and daily fecundity, egg hatching rate, and fertility were determined for E. americanus females and compared to those of A. aphidimyza. Trials were conducted under laboratory conditions in rearing cages on the broad bean plant Vicia faba L. (Fabaceae), infested with pea aphids Acyrthosiphon pisum (Harris) (Hemiptera: Aphididae). The results revealed that the preoviposition period, oviposition period, and adult longevity were significantly longer in E. americanus than in A. aphidimyza. The daily fecundity and egg-hatching rate were similar in both species. However, lifetime fecundity and fertility were considerably higher in E. americanus than in A. aphidimyza. This study demonstrates that the reproductive capacity of E. americanus is clearly superior to that of A. aphidimyza and therefore supports its inclusion in the aphid pest management program as a new biocontrol agent.

The right banker plant for the right application: Comparison of three candidates for aphid biocontrol, barley (Hordeum vulgare L.), corn (Zea mays L.), and finger millet (Eleusine coracana (L.) Gaertn).

BACKGROUND: In temperate regions, aphid biological control in greenhouses is mostly achieved by the regular release of biocontrol agents. Due to the rapid growth rate of the aphid population, biocontrol agents must be released frequently in order to be present before pest outbreaks and to act rapidly to prevent exceeding the economic threshold. Banker plants reduce these numerous releases by providing natural enemies with a high-quality environment to develop and reproduce. Optimally, banker plants should be easy to produce, resistant to environmental conditions, provide a large amount of suitable banker prey in order to produce a high number of biocontrol agents, and resist the herbivory pressure of the banker prey. The present study aimed to compare the value of three banker plant candidates of the Poaceae family under laboratory and greenhouse conditions: barley (Hordeum vulgare L.), finger millet (Eleusine coracana (L.) Gaertn), and corn (Zea mays L.). RESULTS: Our results show that the three plants were suitable for different contexts. Finger millet yielded the biggest fresh plant biomass, supported the highest load of banker prey, and resisted aphid feeding longer than the other plant species. Corn was the cheapest to produce, and barley was the fastest to grow. CONCLUSIONS: Overall, finger millet could be more fitted for long crop cycles, pests with rapid population growth rates, and voracious or fast-reproducing biocontrol agents. Meanwhile, barley and corn may be better suited for rapid crop cycles, pests with slow population growth rates, and biocontrol agents that are not too voracious or have low reproductive rates. © 2024 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Open-source Artificial Pancreas Systems Are Safe and Effective When Supported In-clinic: Outcomes in 248 Consecutive Type 1 Diabetes Clients.

OBJECTIVE: Our aim in this study was to determine the safety, glycemia, and quality of life (QoL) associated with in-clinic installation and management of supported open-source artificial pancreas systems (SOSAPS) in type 1 diabetes (T1D). METHODS: This investigation is a retrospective cohort study of consecutive SOSAPS users at a Canadian diabetes centre. SOSAPS were offered to all moderately tech-savvy T1D clients on sensor-augmented multiple daily injection or pump, able to pay for hardware, and willing to sign a consent and waiver document. SOSAPS were installed and maintained by clinic staff at no cost to clients. iPhone users were assigned to either Loop (n=108) or iPhone artificial pancreas systems (iAPS; n=114) and Android users to Android-type APS (n=24). Outcomes included severe hypoglycemia and diabetic ketoacidosis (DKA), time in range (TIR) 4.0 to 10.0 mmol/L, time below range (TBR) <4 mmol/L, glucose management indicator (GMI), mean sensor glucose (MSG), change in glycated hemoglobin (A1C), and QoL. RESULTS: Two hundred forty-eight subjects (131 males, 117 females), with a mean age of 36 years and diabetes duration of 21 years, experienced 3 episodes of severe hypoglycemia and no DKA over a follow-up of 17 months. TIR rose by 16%, from 64% to 80% (p<0.0001); TBR fell by 1.0%, from 3.5% to 2.5% (p=0.001); MSG fell from 9.0 to 8.1 mmol/L (p<0.001); GMI fell from 7.3% to 6.7% (p<0.001); and A1C fell from 7.2% to 6.7% (p<0.0001). QoL scores were healthy before and improved after SOSAPS. CONCLUSIONS: Clients with T1D using SOSAPS and supported with no-cost care to the client (software, technology, and physician/physician assistant) safely achieved improved TIR, GMI, A1C, and QoL.

Who makes a more consistent first impression? Examining the structure and correlates of dissensus.

OBJECTIVE AND BACKGROUND: How do targets shape consensus in impression formation? Targets are known to play an outsized role in the accuracy of first impressions, but their influence on consensus has been difficult to study. With the help of the recently developed extended Social Relations Model, we explore the structure and correlates of individual differences in consensus (i.e., dissensus). METHOD: Across 3 studies, 187 photographs of targets were rated by 960 perceivers on personality and evaluative traits, as well as being coded for physical cues by trained coders. We explored the within-target consistency of consensus across traits, as well as its relationship to four categories of theoretically relevant correlates: expressiveness, normativity, positivity, and social categories. RESULTS: The tendency to make a consistent impression on others was broadly consistent across traits. High-consensus targets tended to be more expressive, had more normative physical cues, and were viewed more positively. CONCLUSIONS: At least in a first impression context, targets may play a unique role in predicting the consensus of personality judgments by providing perceivers with more information to work with, and making a negative impression on others may carry social costs.

Criterion a of the alternative model of personality disorders: Structure and validity in a community sample.

The alternative model of personality disorders were designed to represent the presence of personality dysfunction (Criterion A) and pathological personality traits (Criterion B). Much of the empirical attention toward this model has been directed toward testing the performance of Criterion B. However, the development of the Levels of Personality Functioning Scale-Self-Report (LPFS-SR) has sparked a growing amount of interest and debate around Criterion A. Specifically, there is significant disagreement in the research examining the validity of the LPFS-SR, with ongoing discrepancies regarding the measure's underlying structure and measurement of Criterion A. The present study aimed to compare four models (one-factor, four-factor, higher order, and bifactor models) in a sample of 416 adults (49.5% women, 63.5% White) to better understand the structure of the LPFS-SR. This study also built on existing efforts to establish convergent and divergent validity of the LPFS-SR by examining how criteria are related to independent measures of both self and interpersonal pathology. The results from the present study supported a bifactor model. Additionally, the four subscales of the LPFS-SR each captured unique variance above and beyond the general factor. Structural equation models predicting identity disturbance and interpersonal traits demonstrated that while the strongest relationships were found between the general factor and the scales, some support was found for the convergent and discriminant validity of the four factors. This work advances our understanding of the LPFS-SR and provides support for the LPFS-SR as a valid marker of personality pathology in clinical and research settings. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Thirty Years of Psychological Wisdom Research: What We Know About the Correlates of an Ancient Concept.

Psychologists have studied the ancient concept of wisdom for 3 decades. Nevertheless, apparent discrepancies in theories and empirical findings have left the nomological network of the construct unclear. Using multilevel meta-analyses, we summarized wisdom's correlations with age, intelligence, the Big Five personality traits, narcissism, self-esteem, social desirability, and well-being. We furthermore examined whether these correlations were moderated by the general approach to conceptualizing and measuring wisdom (i.e., phenomenological wisdom as indexed by self-report vs. performative wisdom as indexed by performance ratings), by specific wisdom measures, and by variable-specific factors (e.g., age range, type of intelligence measures, and well-being type). Although phenomenological and performative approaches to conceptualizing and measuring wisdom had some unique correlates, both were correlated with openness, hedonic well-being, and eudaimonic well-being, especially the growth aspect of eudaimonic well-being. Differences between phenomenological and performative wisdom are discussed in terms of the differences between typical and maximal performance, self-ratings and observer ratings, and global and state wisdom. This article will help move the scientific study of wisdom forward by elucidating reliable wisdom correlates and by offering concrete suggestions for future empirical research based on the meta-analytic findings.

Optimization of a Mass Trapping Method against the Striped Cucumber Beetle Acalymma vittatum in Organic Cucurbit Fields.

The striped cucumber beetle (SCB) Acalymma vittatum (F.) (Coleptera: Chrysomelidae) is a prime problem in North American cucurbit crops. While certain chemical pesticides efficiently control SCB in conventional cucurbit fields, alternative solutions are required due to the ever-evolving regulations on pesticides. For organic producers, very few control methods exist. A novel mass trapping method demonstrates the potential of controlling SCBs using floral-based semiochemical baited traps in cucurbit crops. The goals of this study were to (1) determine whether baited traps capture more SCBs than unbaited ones, and (2) optimize the trapping method by comparing different trap types and different commercially available attractants to maximize SCB captures while minimizing non-target species captures. The results of a first experiment showed that baited traps captured significantly more SCBs than unbaited ones. Baited traps also captured significantly more bees and hoverflies than unbaited ones. In a second experiment these unwanted captures were drastically reduced by using traps with ten 4 mm in diameter holes per side. Finally, a third experiment demonstrated that the attractant 40CT313 was the most efficient at capturing SCB compared to other tested lures. Overall, the optimized mass trapping technique demonstrated a potential to effectively control SCB populations in organic cucurbit crops.

Medial prefrontal activity during self-other judgments is modulated by relationship need fulfillment.

The medial prefrontal cortex (MPFC) plays an important role in representing semantic self-knowledge. Studies comparing semantic self-judgments with judgments of close others suggest that interpersonal closeness may influence the degree to which the MPFC differentiates self and other. We used optical neuroimaging to examine if support for competence, relatedness, and autonomy from relationship partners moderates MPFC activity during a personality judgment task. Participants (N = 109) were asked to judge the descriptive accuracy of trait adjectives for both themselves and a friend. Participants who reported lower need fulfillment with their friend showed elevated activity only in the self-judgment condition; in contrast, participants who reported higher need fulfillment with their friend showed similarly high levels of MPFC activity across the conditions. These results are consistent with the idea that the MPFC differentially represents others on the basis of the need fulfillment experienced within the relationship.

Interpersonal traits and the neural representations of cognitive control in the prefrontal cortex.

Adaptive interpersonal functioning relies on the effectiveness of behavioral and neural systems involved in cognitive control. Whether different subcomponents of cognitive control and their neural representations are associated with distinctive interpersonal dispositions has yet to be determined. The present study investigated the relationships between prefrontal cortex (PFC) activation associated with two subcomponents of cognitive control and individual differences in interpersonally relevant traits and facets within the Five-Factor Model of personality. Undergraduate participants (n = 237) provided self-ratings of interpersonal traits and underwent functional near-infrared spectroscopy to measure activation in regions-of-interest linked to subcomponents of cognitive control: the right lateral PFC and its involvement in response selection and inhibition/suppression (RS) during a go/no-go task, and the left lateral PFC associated with goal selection, updating, representation, and maintenance (GS) on a tower planning task. Multilevel models revealed that during both RS and GS, Neuroticism and Extraversion were associated with lower and higher levels of activation, respectively. Higher Agreeableness was related to lower activation during RS but also with greater activation during GS. More narrowly defined interpersonal facets subsumed within the broader trait domains were differentially associated with RS- and GS-related neural responses. Taken together, these findings highlight potential avenues of future research to better understand the ways in which the neural processes that subserve cognitive control may underlie interpersonal dispositions.

Bridging development and disturbance: A translational approach to the study of identity.

Across the subdisciplines of personality and clinical psychology, identity has been a psychological construct of wide-reaching importance in understanding both normative processes of human development as well as psychopathology. However, despite its wide-reaching importance, differences in the conceptualization and measurement of identity across these subdisciplines have contributed to more fragmentation, rather than unification, in our understanding of this central principle. In the present study, we sought to unify the measurement of identity across these subdisciplines through examining the extent to which personality and clinical measures of identity converge, as well as the predictive validity of identity measures across layers of personality functioning, employing a unique design for a dynamic assessment of identity. Our results supported a 1-factor model, as opposed to a 2-factor model, of identity. This Identity/Identity Dysfunction factor was significantly associated with mean-level neuroticism, extraversion, and agreeableness, but not significantly associated with stability of personality trait expression. It was also associated with more extrinsic values and aspirations, and the stability of extrinsic aspirations. Finally, the Identity/Identity Dysfunction factor demonstrated moderate and negative relationships with indices of narrative coherence. Our results suggest that identity falls along a continuum of development and disturbance and is meaningfully connected to all layers of personality functioning. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

May predator body-size hamper furtive predation strategy by aphidophagous insects?

Furtive predation is an uncommon predation strategy within aphidophagous insects, as it can be constrained by several factors. So far, the few reported furtive predators are characterized by their small body-size, vermiform shape, and slow movement. They live within the aphid colonies, without triggering significant defensive acts, nor disrupting colony structure. In this study, we aim to determine how body-size may prevent adoption of a furtive predation strategy. For that, the American hoverfly, Eupeodes americanus (Wiedemann) (Diptera: Syrphidae) was selected as a model species, according to the great body-size increase experienced during the larval stage. We hypothesized that smaller instars will be furtive predators, whereas larger ones will be active-searching predators. After the inoculation close to a pea aphid, Acyrthosiphon pisum (Harris) (Hemiptera: Aphididae) colony, several behavioral parameters of the different larval instars were recorded. The elicited aphid colony disturbance was also evaluated and compared with that of the active-searching ladybird beetle, Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae), and of the furtive predator, Aphidoletes aphidimyza (Rondani) (Diptera: Cecidomyiidae). Aphids showed significantly fewer defensive behaviors in the presence of E. americanus larvae than in the presence of the active-searching H. axyridis. Furthermore, our results clearly indicate that body-size increase was not a limit, since the three larval instars of the American hoverfly acted as furtive predators, just like the furtive A. aphidimyza. It is the first time a furtive predatory behavior has been recorded on such a large aphidophagous predator. The obtained results provide essential information about the biology of E. americanus, a potential biological control agent of aphids.

Dimensions of human hierarchy as determinants of health and happiness.

No matter what rung someone holds on the social ladder, they are likely to experience better health and happiness than those below them in the hierarchy and poorer health and happiness than those above. Social gradients have been found for cardiovascular, respiratory, rheumatoid, and psychiatric disease as well as mortality from all causes. These findings are often mediated by subjective social status, defined as a person's perceptions of their place in the social structure. Social gradients have also been found for happiness, which seems to be affected by sociometric status (i.e. being respected by others) more than by socioeconomic status (e.g. income). I conclude by considering the extent to which social hierarchies scaffold the fulfillment of people's basic psychological needs.

Evaluation of Two Potential Biological Control Agents Against the Foxglove Aphid at Low Temperatures.

The foxglove aphid, Aulacorthum solani Kaltenbach (Hemiptera: Aphididae), has become a significant pest in horticulture as it can up build high populations from 10 to 18°C. Currently, chemical control is used as no commercially available biocontrol agent is effective at these temperatures. In this study, two potential biocontrol agents were evaluated: the silverfly, Leucopis glyphinivora Tanasijtshuk (Diptera: Chamaemyiidae), and the American hoverfly, Eupeodes americanus (Wiedemann) (Diptera: Syrphidae). Active flight, oviposition, and larval voracity were tested at 12, 15, and 18°C. The proportion of individuals demonstrating flight decreased at 12°C for the hoverfly and decreased at 15 and 12°C for the silverfly. Delay before active flight was greater for both species at 12°C. More hoverflies laid eggs after 7 d at all temperatures (12, 15, and 18°C) compared with silverflies. Hoverflies laid a higher number of eggs than silverflies at all temperatures. When given an additional 7 d at 12°C, oviposition increased for both species. Daily aphid consumption decreased as temperature decreased for both species, but average total aphid consumption did not decrease regardless of the temperature. This means that larval voracity for both the silvery and the American hoverfly was similar at all temperatures (12, 15, and 18°C) when considering aphid development. Hoverfly larvae consumed two times more aphids than silverfly larvae at all temperatures. This study demonstrates a clear superiority of the hoverfly over the silverfly at low temperatures and identifies it as a potential biocontrol agent of the foxglove aphid.

The Signs and Significance of Personality Coherence in Personal Stories and Strivings.

The concept of personality coherence refers to the extent of psychological unity and wholeness embodied within each individual. In the present research, we examined the extent to which the narrative, functional, and organismic conceptualizations of personality coherence interrelate, as well as their associations with psychological abilities and personal adjustment. College students ( N = 391) narrated accounts of three personal memories; listed five personal strivings that they subsequently compared and evaluated; completed performance measures of their intelligence, wisdom, and creativity; and rated their hedonic and eudaimonic well-being. Individuals who coherently organized their autobiographical memories were protected against feeling pressured or compelled in their personal strivings and against being steered toward need-detracting futures. Narrative indicators of coherence were otherwise independent of the functional and organismic indicators, although all indicators of personality coherence correlated with personal adjustment. Wisdom and creativity predicted narrative coherence, which partially mediated the associations they demonstrated with eudaimonic well-being.

"It was the best worst day of my life": Narrative Content, Structure, and Process in Wisdom-Fostering Life Event Memories.

Objectives: The purpose of this study was to examine laypeople's subjective understanding of their own wisdom development. To do this, autobiographical memories of wisdom-fostering life events were examined for (a) life-event characteristics, and (b) self-reflective processes believed to support growth in wisdom through life experience. Methods: Midlife adults (N = 482) provided a written autobiographical memory of a wisdom-fostering life event. Memories were content analyzed by expert coders for life-event characteristics (i.e., fundamentality, emotional valence, cultural normativity, and specific event types) and self-reflective processes (i.e., narrative coherence, meaning-making, and personal growth). Participants also completed self-report and performance measures of wisdom. Results: Wisdom-fostering life events tended to be fundamental to life, culturally non-normative, and emotionally negative. Participants frequently reported developing wisdom from relationship events (e.g., interpersonal conflict, divorce) and life-threatening/mortality events (e.g., death, serious illness). Wisdom was positively associated with reconstructive (i.e., narrative coherence) and analytical (i.e., meaning-making, personal growth) components of self-reflection. Self-reflective processes varied as a function of life-event characteristics. Discussion: This study emphasizes the role of both persons and environments in the development of wisdom, and highlights the importance of self-reflection as a mechanism through which wisdom is constructed from life experience.

Consequence of intraventricular hemorrhage on neurovascular coupling evoked by speech syllables in preterm neonates.

Intraventricular Hemorrhage (IVH) is the leading cause of neurological and cognitive impairment in preterm neonates with an incidence that increases with increasing prematurity. In the present study, we tested how preterm neonates with IVH react to external stimulation (i.e. speech syllables). We compared their neural responses measured by electroencephalography (EEG), and hemodynamic responses measured by functional near-infrared spectroscopy (fNIRS), with those of healthy preterms. A neural response to syllables was observed in these infants, but did not induce a vascular response in contrast with healthy neonates. These results clearly demonstrate that the cerebral vascular network in IVH preterm neonates was unable to compensate for the increased metabolism resulting from neuronal activation in response to external stimulation. Optical imaging is thus a sensitive tool to identify altered cerebral hemodynamic in critically ill preterms before behavioral changes are manifested or when only minor abnormalities on other functional monitoring techniques such as EEG are visible. We propose that a multi-modal approach provides unique opportunities for early monitoring of cognitive functions and opens up new possibilities for clinical care and recommended practices by studying the difficulties of the premature brain to adapt to its environment.

Adverse Events With Ketamine Versus Ketofol for Procedural Sedation on Adults: A Double-blind, Randomized Controlled Trial.

OBJECTIVES: The goal of our study was to compare the frequency and severity of recovery reactions between ketamine and ketamine-propofol 1:1 admixture ("ketofol"). METHODS: We performed a multicentric, randomized, double-blind trial in which adult patients received emergency procedural sedations with ketamine or ketofol. Our primary outcome was the proportion of unpleasant recovery reactions. Other outcomes were frequency of interventions required by these recovery reactions, rates of respiratory or hemodynamic events, emesis, and satisfaction of patients as well as providers. RESULTS: A total of 152 patients completed the study, 76 in each arm. Compared with ketamine, ketofol determined a 22% reduction in recovery reactions incidence (p < 0.01) and less clinical and pharmacologic interventions required by these reactions. There was no serious adverse event in both groups. Rates in hemodynamic or respiratory events as well as satisfaction scores were similar. Significantly fewer patients experienced emesis with ketofol, with a threefold reduction in incidence compared with ketamine. CONCLUSION: We found a significant reduction in recovery reactions and emesis frequencies among adult patients receiving emergency procedural sedations with ketofol, compared with ketamine.

Basic psychological needs and neurophysiological responsiveness to decisional conflict: an event-related potential study of integrative self processes.

Fulfillment of the basic psychological needs for competence, relatedness, and autonomy is believed to facilitate people's integrative tendencies to process psychological conflicts and develop a coherent sense of self. The present study therefore used event-related potentials (ERPs) to examine the relation between need fulfillment and the amplitude of conflict negativity (CN), a neurophysiological measure of conflict during personal decision making. Participants completed a decision-making task in which they made a series of forced choices according to their personal preferences. Three types of decision-making situations were created on the basis of participants' unique preference ratings, which were obtained prior to ERP recording: low-conflict situations (choosing between an attractive and an unattractive option), high-conflict approach-approach situations (choosing between two similarly attractive options), and high-conflict avoidance-avoidance situations (choosing between two similarly unattractive options). As expected, CN amplitudes were larger in high- relative to low-conflict situations, and source localization analyses suggested that the anterior cingulate cortex was the generating structure of the CN. Most importantly, people reporting higher need fulfillment exhibited larger CN amplitudes in avoidance-avoidance situations relative to low-conflict situations; to a lesser extent, they also exhibited larger CN amplitudes in approach-approach situations relative to low-conflict situations. By contrast, people reporting lower need fulfillment exhibited CN amplitudes that poorly discriminated the three decision situations. These results suggest that need fulfillment may promote self-coherent functioning by increasing people's receptivity to and processing of events that challenge their abilities to make efficient, self-congruent choices.

Decision-making conflict and the neural efficiency hypothesis of intelligence: a functional near-infrared spectroscopy investigation.

Research on the neural efficiency hypothesis of intelligence (NEH) has revealed that the brains of more intelligent individuals consume less energy when performing easy cognitive tasks but more energy when engaged in difficult mental operations. However, previous studies testing the NEH have relied on cognitive tasks that closely resemble psychometric tests of intelligence, potentially confounding efficiency during intelligence-test performance with neural efficiency per se. The present study sought to provide a novel test of the NEH by examining patterns of prefrontal activity while participants completed an experimental paradigm that is qualitatively distinct from the contents of psychometric tests of intelligence. Specifically, participants completed a personal decision-making task (e.g., which occupation would you prefer, dancer or chemist?) in which they made a series of forced choices according to their subjective preferences. The degree of decisional conflict (i.e., choice difficulty) between the available response options was manipulated on the basis of participants' unique preference ratings for the target stimuli, which were obtained prior to scanning. Evoked oxygenation of the prefrontal cortex was measured using 16-channel continuous-wave functional near-infrared spectroscopy. Consistent with the NEH, intelligence predicted decreased activation of the right inferior frontal gyrus (IFG) during low-conflict situations and increased activation of the right-IFG during high-conflict situations. This pattern of right-IFG activity among more intelligent individuals was complemented by faster reaction times in high-conflict situations. These results provide new support for the NEH and suggest that the neural efficiency of more intelligent individuals generalizes to the performance of cognitive tasks that are distinct from intelligence tests.

Evaluation of transport ventilators at mild simulated altitude: a bench study in a hypobaric chamber.

BACKGROUND: Previous studies on ventilators used for air transport showed significant effects of altitude, in particular with regard to accuracy of the tidal volume (VT) and breathing frequency. The aim of the study was to evaluate transport ventilators under hypobaric conditions. METHODS: We conducted a bench study of 6 transport ventilators in a Comex hypobaric chamber to simulate mild altitude (1,500 m [4,920 feet] and 2,500 m [8,200 feet]). The ventilators were connected to a test lung to evaluate their accuracy: (1) to deliver a set VT under normal resistance and compliance conditions at F(IO2) = 0.6 and 1, (2) to establish a set PEEP (0, 5, 10, and 15 cm H2O), and (3) to establish a set inspiratory pressure in pressure controlled mode, (4) at a F(IO2) setting, and (5) and at a frequency setting. RESULTS: Four ventilators kept an average relative error in VT of < 10% without effect of altitude. The Medumat ventilator was affected by the altitude only at F(IO2) = 1. The Osiris 3 ventilator had > 40% error even at 1,500 m. We found no change in frequency as a function of altitude for any ventilators studied. No clinically important differences were found between all altitudes with the PEEP or inspiratory pressure setting. Although F(IO2) was affected by altitude, the average error did not exceed 11%, and it is unclear whether this fact is an experimental artifact. CONCLUSIONS: We have shown that most of the new transport ventilators tested require no setting adjustment at moderate altitude and are as safe at altitude as at sea level under normal respiratory conditions. Older technologies still deliver more volume with altitude in volumetric mode.