Learning basic arithmetic: A comparison between rote and procedural learning based on an artificial sequence

It is commonly accepted that repeatedly using mental procedures results in a transition to memory retrieval, but the determinant of this process is still unclear. In a 3-week experiment, we compared two different learning situations involving basic additions, one based on counting and the other based on arithmetic fact memorization. Two groups of participants learned to verify additions such as "G + 2 = Q?" built on an artificial sequence (e.g., "XGRQD…"). The first group learned the sequence beforehand and could therefore count to solve the problems, whereas the second group was not aware of the sequence and had to learn the equations by rote. With practice, solution times of both groups reached a plateau, indicating a certain level of automatization. However, a more fine-grained comparison indicated that participants relied on fundamentally different learning mechanisms. In the counting condition, most participants showed a persistent linear effect of the numerical operand on solution times, suggesting that fluency was reached through an acceleration of counting procedures. However, some participants began memorizing the problems involving the largest addends: Their solution times were very similar to those of participants in the rote learning group, suggesting that they resulted from a memory retrieval process. These findings show that repeated mental procedures do not systematically lead to memory retrieval but that fluency can also be reached through the acceleration of these procedures. Moreover, these results challenge associationist models, which cannot currently predict that the process of memorization begins with problems involving the largest addends. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Between-item similarity frees up working memory resources through compression: A domain-general property

Compression, the ability to recode information in a denser format, is a core property of working memory (WM). Previous studies have shown that the ability to compress information largely benefits WM performance. Importantly, recent evidence also suggests compression as freeing up WM resources, thus enhancing recall performance for other, less compressible information. Contrary to the traditional view positing that between-item similarity decreases WM performance, this study shows that between-item similarity can be used to free up WM resources through compression. Across a series of four experiments, we show that between-item similarity not only enhances recall performance for similar items themselves, but also for other, less compressible items within the same list, and this in the semantic (Experiment 1), phonological (Experiment 2), visuospatial (Experiment 3), and visual (Experiment 4) domains. Across these different domains, a consistent pattern of results emerged: between-item similarity proactively-but not retroactively-enhanced WM performance for other items, and this as compared with a condition in which between-item similarity at the whole-list level was minimized. We propose that between-item similarity in any domain may impact WM using the same underlying machinery: via a compression mechanism, which allows an efficient reallocation of WM resources. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

[Severe adult asthma and treatment adherence: Results of the FASE-CPHG study]

INTRODUCTION

Data on severe asthma in France are scarce. The aim of this study was to evaluate adherence to asthma treatments and its determinants in a population of severe asthmatics.

METHODS

From May 2016 to June 2017, the French Collège des Pneumologues des Hôpitaux Généraux organized a large-scale prospective, cross-sectional, multicenter study on this topic; 1502 patients with severe asthma were included.

RESULTS

The average number of substantive treatments was 2.5±1.1. Assessed by self-questionnaire in 1289 patients, overall adherence was 64.8%, in good agreement with the findings of the pneumologist in charge (p<0.0001). Control of asthma according to the GINA criteria was more successful in compliant patients (p<0.01). In univariate analysis, the most compliant participants were frequent exacerbator patients (p=0.02), those with nasal polyposis (p=0.01) and those receiving an anticholinergic agent (p<0.01), anti-IgE biotherapy (p<0.0001) or oral corticosteroids (p<0.01). The least compliant participants were younger (p<0.0001), active smokers (p<0.001), with shorter average disease duration (24.2±15.7 vs 29.1±18.7 years, p<0.0001) and a lower number of substantive asthma treatments (2.2±1 vs 2.6±1, p<0.0001). In multivariate analysis, age, length of disease and anti-IgE treatment were the only factors affecting therapeutic compliance.

CONCLUSION

In this large-scale study of severe asthmatic patients, 64.8% were compliant according to the MMAS-4© self-administered questionnaire and appeared to be better monitored according to the criteria defined in our study. Overall, adherence was more satisfactory among older patients and those whose disease had been evolving over a long period of time or were receiving anti-IgE biotherapy.

Can activated long-term memory maintain serial order information?

The maintenance of serial order information is a core component of working memory (WM). Many theoretical models assume the existence of specific serial order mechanisms. Those are considered to be independent from the linguistic system supporting maintenance of item information. This is based on studies showing that psycholinguistic factors strongly affect the ability to maintain item information, while leaving order recall relatively unaffected. Recent language-based accounts suggest, however, that the linguistic system could provide mechanisms that are sufficient for serial order maintenance. A strong version of these accounts postulates serial order maintenance as emerging from the pattern of activation occurring in the linguistic system. In the present study, we tested this assumption via a computational modeling approach by implementing a purely activation-based architecture. We tested this architecture against several experiments involving the manipulation of semantic relatedness, a psycholinguistic variable that has been shown to interact with serial order processing in a complex manner. We show that this activation-based architecture struggles to account for interactions between semantic knowledge and serial order processing. This study fails to support activated long-term memory as an exclusive mechanism supporting serial order maintenance.

Complications and cost of single-stage vs. two-stage bilateral unicompartmental knee arthroplasty: A case-control study

BACKGROUND

Single-stage bilateral knee arthroplasty, even when unicompartmental, remains controversial, chiefly due to the risk of peri-operative complications. The primary objective of this study was to compare the short-term complication rate and cost of single- vs. two-stage bilateral unicompartmental knee arthroplasty (UCA). The secondary objective was to compare total hospital stay lengths and motion-range recovery.

HYPOTHESIS

Single-stage bilateral UCA is a cost-saving alternative that is not associated with higher complication rates compared to two-stage bilateral UCA.

MATERIAL AND METHOD

This single-centre retrospective comparative study included 70 patients of any age managed between 2010 and 2016. Among them, 44 (88 UKAs) had single-stage surgery (1S group) and 26 (52 UCAs) two-stage surgery (2S group). The two groups were comparable for age, body mass index, gender distribution, compartment replaced, ASA score, and Charlson comorbidity index. The following were evaluated: operative time, haemoglobin level before and after surgery, major and minor complication rates, motion-range recovery, and the radiographic hip-knee-ankle (HKA) angle. Costs were estimated based on the standard codes assigned to the procedures by the national statutory health insurance system (GHM 08C24 for knee arthroplasty to treat knee osteoarthritis and NFKA006 for unicompartmental tibio-femoral or femoro-patellar arthroplasty), modulated according to the concomitant diagnoses.

RESULTS

No differences were found for the haemoglobin level change, time to motion-range recovery, or HKA angle. The complication rates per patient were not significantly different between the groups: major complications, 9.1% (n=4) in the 1S group and 15.4% (n=4) in the 2S group (p=1.00); minor complications, 4.5% (n=2) in the 1S group and 3.8% (n=1) in the 2S group (p=1.00). Cost of the total hospital stay was significantly higher in the 2S group than in the 1S group (11,766.7€) and 5626.4€, respectively; p<0.001). Mean total hospital stay duration per patient was 6.7 days with single-stage surgery and 13.4 days with two-stage surgery.

DISCUSSION

Single-stage bilateral UCA is not associated with a higher rate of peri-operative complications compared to the two-stage alternative and is substantially less costly. Financial incentives from the healthcare authorities are warranted to increase the use of the single-stage procedure.

LEVEL OF EVIDENCE

III, case-control study.

What makes working memory traces stable over time?

Understanding the factors that make working memory (WM) traces stable over time is important because WM is the keystone of general cognitive achievement. Two views of attentional WM maintenance have been suggested to account for the long-term retention of WM information. First, the distractors in a WM task are thought to foster the creation of episodic memory cues through covert retrieval. Second, the cognitive load (CL) of the distractors is thought to vary long-term memory instantiation. In this study, we propose an additional parsimonious perspective: the total time during which each trace is under the control of attention in WM is the key to long-term retention. Participants performed a complex span task in which the CL and number of distractors were orthogonally manipulated, and thereafter the participants performed a delayed recall test. Similar to previous findings, the results showed effects of the number of distractors and of CL on delayed recall. Our results went further, however, by showing a non-linear relationship between delayed recall performance and the free time accumulated between encoding and immediate recall. The role of time in episodic memory performance and the underlying WM maintenance mechanism are discussed.

A Computational Model of Working Memory Integrating Time-Based Decay and Interference

There is still a strong debate in the working memory literature about the cause of forgetting, with many articles providing evidence for the existence of temporal decay and as many publications providing evidence compatible with interference being the only mechanism involved in forgetting. In order to reconcile the two views, this article describes TBRS∗-I (for Time-Based Resource-Sharing∗-Interference), a computational model of working memory which incorporates an interference-based mechanism to the decay-based implementation TBRS∗ within the TBRS theoretical framework. At encoding, memoranda are associated to their context, namely their position in the list. Temporal decay decreases the strength of these associations, but a refreshing process may reactivate it during free time. Distractors may alter the distributed representation of memoranda but refreshing can restore them based on the long-term memory representations. Refreshing is therefore twofold: reactivation plus restoration, each one counteracting the detrimental time-based and interference-based decays, respectively. Two types of interference are implemented: interference by confusion which depends on the degree of overlap between memoranda and distractors and interference by superposition which depends on the similarity between them. TBRS∗-I was tested on six benchmark findings on retention-interval and distractor-processing effects by means of millions of simulations testing the effects of seven factors on memory performance: the number of memoranda, the duration of distractor attentional capture, the duration of free time, the number of distractors, the amount of overlap between memoranda and distractors, the similarity between memoranda and distractors and the homogeneity of distractors (all identical or all distinct). TBRS∗-I replicated classical effects and proved to be a suitable hybrid model integrating both interference and time-based decay. The article also discusses the compatibility of TBRS∗-I with a unitary or dual view of memory and the issue of integrating time and interference in a single model. Computer codes and data are available at https://osf.io/65sna/.

Immediate coronary angiography in survivors of out-of-hospital cardiac arrest without obvious extracardiac cause: Who benefits?

BACKGROUND

Immediate coronary angiography (iCA) and primary percutaneous coronary angioplasty (pPCI) in patients successfully resuscitated after out-of-hospital cardiac arrest (OHCA) of suspected cardiac cause is controversial. Our aims were to assess the results of iCA, the prognostic impact of pPCI after OHCA, and to identify subgroups most likely to benefit from this strategy.

METHODS

In this single-centre retrospective study, patients aged ≥18 years with sustained return of spontaneous circulation after OHCA and no evidence of a non-cardiac cause underwent routine iCA at admission, with pPCI if indicated. Results of iCA, and factors associated with in-hospital survival were analysed.

RESULTS

Between 2006 and 2013, 160 survivors from OHCA presumed of cardiac origin were included (median age, 60 years; 85% males). iCA showed significant coronary-artery lesions in 75% of patients, and acute occlusion or unstable lesion in only 41%. pPCI was performed in 34% of patients and was not associated with survival by univariate or multivariate analysis (P=0.67). ST-segment elevation predicted acute coronary occlusion in 40%. An initial shockable rhythm was associated with higher in-hospital survival (52% vs. 19%; P<0.001). After initial defibrillation, the first rhythm recorded by 12-lead electrocardiography was highly associated with prognosis: secondary asystole had a very low survival rate (5%, 1/21) despite PCI in 43% of patients, compared to sustained ventricular tachycardia/fibrillation (42%, 15/36) and supraventricular rhythm (71%, 50/70) (P<0.001).

CONCLUSIONS

In our experience, the prevalence of acute coronary occlusion or unstable lesion immediately after OHCA of likely cardiac cause is only 41%. Immediate CA in OHCA survivors, with pPCI if indicated, should be restricted to highly selected patients.

Accumulation of neurotoxic organochlorines and trace elements in brain of female European eel (Anguilla anguilla)

Xenobiotics such as organochlorine compounds (OCs) and metals have been suggested to play a significant role in the collapse of European eel stocks in the last decades. Several of these pollutants could affect functioning of the nervous system. Still, no information is so far available on levels of potentially neurotoxic pollutants in eel brain. In present study, carried out on female eels caught in Belgian rivers and canals, we analyzed brain levels of potentially-neurotoxic trace elements (Ag, Al, As, Cd, Co, Cr, Cu, Fe, Hg, MeHg, Mn, Ni, Pb, Sn, Sb, Zn) and OCs (Polychlorinated biphenyls, PCBs; Hexachlorocyclohexanes, HCHs; Dichlorodiphenyltrichloroethane and its metabolites, DDTs). Data were compared to levels in liver and muscle tissues. Eel brain contained very high amounts of OCs, superior to those found in the two other tissues. Interestingly, the relative abundance of PCB congeners markedly differed between tissues. In brain, a predominance of low chlorinated PCBs was noted, whereas highly chlorinated congeners prevailed in muscle and liver. HCHs were particularly abundant in brain, which contains the highest amounts of β-HCH and ϒ-HCH. p,p'-DDTs concentration was similar between brain and muscle (i.e., about twice that of liver). A higher proportion of p,p'-DDT was noticed in brain. Except for Cr and inorganic Hg, all potentially neurotoxic metals accumulated in brain to levels equal to or lower than hepatic levels. Altogether, results indicate that eel brain is an important target for organic and, to a lesser extent, for inorganic neurotoxic pollutants.

Unplanned return to theater: A quality of care and risk management index?

INTRODUCTION

Surgical quality and risk management is a major public health issue. The consequences of unplanned return to theater are social, occupational, financial and even legal. Unscheduled revision surgery is a major adverse event, resulting from serious complications - some of which are thought to be avoidable. The present study sought to assess and analyze the incidence of unplanned return to theater in an orthopedic surgery department. The study hypothesis was that some of the complications involved could be avoided.

PATIENTS AND METHOD

A mixed retrospective-prospective study examined a consecutive series of 10,158 patients operated on in an orthopedic and traumatologic surgery department between January 2011 and December 2013. Patients undergoing revision surgery for reasons directly related to the primary procedure were analyzed. Patients were distributed among the following subgroups: infection, implant dislocation; hemorrhagic complication, mechanical complication, problem of primary technique, stiffness, wound healing disorder. Specific indicators of dysfunction liable to have contributed to onset of the complication were applied in each subgroup, to determine the avoidable or unavoidable nature of the event.

RESULTS

Two hundred and twenty-four patients (2.2%) underwent revision surgery for reasons directly related to the primary procedure. One hundred and eight cases (48.2%) were considered to have been avoidable: 48 infections (21.4%), 27 implant dislocations (12%), 15 hemorrhagic complications (6.7%), 66 mechanical complications (29.5%), 35 technical problems at primary surgery (15.6%), 21 cases of stiffness (9.3%), and 12 cases of delayed wound healing (5.3%). Mean time to revision surgery was 2.7 ± 2.6 months. Extending the time-window to 1 year recruited extra cases: in 31.7% of cases, onset was after the 90th postoperative day, which is the usual deadline. The rate of unplanned return to theater was higher after unscheduled (traumatic: 3.2%) than scheduled surgery (1.7%, P < 0.001).

CONCLUSION

Return to surgery in orthopedic and traumatologic surgery is underestimated. Annual incidence was 2.2%, and twice as high (3.2%) following traumatologic compared to scheduled surgery (1.7%). Analysis found that almost half the cases were avoidable. They represent a relevant and easily assessed indicator of treatment quality and associated risk management. A national or even international database in the form of an anonymous registry of revision surgeries would be useful.

An Analysis of Reading Skill Development using E-Z Reader

Previously reported simulations using the E-Z Reader model of eye-movement control suggest that the patterns of eye movements observed with children versus adult readers reflect differences in lexical processing proficiency (Reichle et al., 2013). However, these simulations fail to specify precisely what aspect(s) of lexical processing (e.g., orthographic processing) account for the concurrent changes in eye movements and reading skill. To examine this issue, the E-Z Reader model was first used to simulate the aggregate eye-movement data from 15 adults and 75 children to replicate the finding that gross differences in reading skill can be accounted for by differences in lexical processing proficiency. The model was then used to simulate the eye-movement data of individual children so that the best-fitting lexical-processing parameters could be correlated to measures of orthographic knowledge, phonological-processing skill, sentence comprehension, and general intelligence. These analyses suggest that orthographic knowledge accounts for variance in the eye-movement measures that is observed with between-individual differences in reading skill. The theoretical implications of this conclusion will be discussed in relation to computational models of reading and our understanding of reading skill development.

[Depression as a common complication of systemic lupus erythematosus]

Systemic lupus erythematosus (SLE) is an inflammatory disease with multiple and disabling consequences, including the psychological status. The prevalence of major depressive episodes among patients suffering from SLE is significantly higher than in healthy people, or people suffering from other inflammatory diseases. While it is obvious that its chronic disease status with a frequently pejorative ending, as well as the number of treatments it requires, are contributing factors, it is likely that due to its pathogenic mechanisms, SLE causes direct injury to the brain, leading to a depressive symptomatology. Numerous hypotheses are under consideration. We shall review them all, recall a few epidemiologic features, add histology and medical imaging contributions and discuss the importance of setting up a fitting therapy for such patients.

[Ten-year evolution in non-small-cell lung cancer according to sex. Results of the KBP-2010-CPHG study by the College of General Hospital Respiratory Physicians]

INTRODUCTION

Comparison by sex and presenting features between 2000 and 2010 of the characteristics of new cases of non-small-cell lung cancer (NSCLC).

METHODS

Observational KBP-2010-CPHG study similar to KBP-2000-CPHG. Both studies were promoted by the French College of General Hospital Respiratory Physicians (CPHG). KBP-2010-CPHG collected data for 6083 NSCLC diagnosed between January 1st and December 31st, 2010, and followed in the respiratory departments of 119 French general hospitals.

RESULTS

In 2010, 24.4 % of the patients were women (16 % in 2000, p<0.0001). Compared to men, women were more commonly non-smokers (34.2 vs 4.7 %) or lighter consumers (37.2 vs 43.7 pack per years) (p<0.0001). Their tumours (mostly adenocarcinoma: 64.6 vs 48.7 %, p<0.0001) were more frequently diagnosed at stage IV (62.4 vs 56.9 %, p=0.0008). EGFR mutation research was more frequently performed (48.5 vs 31.0 %, p<0.0001) and positive (20.6 vs 5.2 %, p<0.0001) in women than men. Their treatment more frequently included targeted therapy (13.4 vs 5.7 %, p<0.0001). Compared to 2000, the percentage of non-smokers increased in men (4.7 vs 2.5 %, p<0.0001) while remaining stable in women (36.1 vs 34.2 %, p=0.32). The percentage of adenocarcinomas increased, particularly in men (48.7 vs 31.5 %, p<0.0001).

CONCLUSIONS

The percentage of women with NSCLC has increased in 10years in France. In 2010, the main gender differences persist, but have decreased with the increasing proportion of non-smokers and adenocarcinomas in men. Various hypotheses to explain these changes are discussed.

[Anal sphincter tears after vaginal delivery: risks factors and means of prevention]

To identify incidence and risks factors of obstetrical anal sphincter lacerations, we reviewed all cases of 3rd and 4th degree sphincter lacerations after vaginal deliveries (VD) occured in a tertiary maternity between 2005 and 2010. 78 anal sphincter lacerations were identified (3.8/1000 deliveries). 66 women (85%) were nulliparous. The mean age of women was of 29 +/- 5 years. The mean duration of the second stage of labour was of 3.4 +/- 1,7 hour. The birth weight of 12 newborns (15%) was greater than 4000 grams. Fourty-six women (2.5%) had sphincter lacerations after instrumental delivery and 32 after spontaneous vaginal delivery (0.2%). 51 patients out of 78 (65%) had a medio-lateral episiotomy, 82% occured after instrumental extraction and 43% after spontaneous delivery. A forceps of Tarnier was used in 18 cases, a Suzor forceps in 12 cases, spatula in 12 cases and vacuum in 4 cases. 76% of foetuses were in anterior presentation and 78% at the medium part of the pelvis. 2 patients experienced anal incontinence in early post-partum. Anal sphincter lacerations are relatively frequent after VD especially after instrumental delivery. Macrosomia, nulliparous women, prolonged second stage of labor were associated with anal sphincter tears. Medio-lateral episiotomy does not protect enough anal sphincters. Anal sphincter lacerations lead to anal incontinence in some cases.A long follow-up is useful for these patients.

[Gynecological emergencies: etiology and degree of gravity]

OBJECTIVE

To evaluate the type and the emergency degree of the pathologies met in gynecological emergencies.

METHODS

prospective study including 205 patients presented to the Emergency department of a maternity level 3 between the 2011 January 4 and February 15.

RESULTS

One hundred and ninety-four patients (95%) came from their own initiative. One hundred and eighty-one patients (88%) consulted for abdominal/pelvic or lumbar pain and or metrorragia. The mean age of the patients was of 31 ± 11 years and the average waiting time before being examined was of 84 ± 101 minutes. For 94 patients (46%), the diagnosis was an asymptomatic intra-uterine pregnancy in 41 cases or associated with minor symptoms. 21 patients (8.9%) consulted for menstruation with or without dysmenorrhea, 17 (8,3%) had a miscarriage, 14 (7%) a genital infection, 11 (5%) an ovarian pathology and eight (4%) an ectopic pregnancy or its follow-up. Seven patients had an axillary lymphocele or a breast tumor and four symptomatic myomas. Six patients presented with non-gynecological pathologies. In 23 cases (11%) no organic cause was found. Only 24 patients (12%) were hospitalized and nine (4.5%) operated.

CONCLUSION

Most of the patients consulted for minor obstetrical or gynecological pathologies without relation with the function of Emergency department. Ectopic pregnancy remains a rare event. Better information of the users on the significance of the urgency is desirable. Consultation of a referent physician before emergency services should be privileged.

MDLChunker: a MDL-based cognitive model of inductive learning

This paper presents a computational model of the way humans inductively identify and aggregate concepts from the low-level stimuli they are exposed to. Based on the idea that humans tend to select the simplest structures, it implements a dynamic hierarchical chunking mechanism in which the decision whether to create a new chunk is based on an information-theoretic criterion, the Minimum Description Length (MDL) principle. We present theoretical justifications for this approach together with results of an experiment in which participants, exposed to meaningless symbols, have been implicitly encouraged to create high-level concepts by grouping them. Results show that the designed model, called hereafter MDLChunker, makes precise quantitative predictions both on the kind of chunks created by the participants and also on the moment at which these creations occur. They suggest that the simplicity principle used to design MDLChunker is particularly efficient to model chunking mechanisms. The main interest of this model over existing ones is that it does not require any adjustable parameter.

Proximal ulna comminuted fractures: fixation using a double-plating technique

INTRODUCTION

Comminuted fractures of the proximal ulna are severe injuries often associated with bone and ligament injuries of the elbow joint (Monteggia lesion, radial head fractures, dislocation of the elbow). The treatment of these fractures is very demanding and the functional results often fairly mediocre due to associated injuries. Based on a single-center retrospective study, we report the results of the treatment of these fractures fixed using a double-plate technique. The aim was to evaluate the feasibility and reliability of this fixation mode and to compare it with other fractures series using a single plate fixation (in terms of bone union, elbow joint function, and complications stemming from the plates).

PATIENTS AND METHODS

Eighteen patients sustained a comminuted proximal ulna fracture between 2002 and 2006. The fractures were associated in five cases with a Monteggia type lesion, in two cases with elbow dislocation, and in four cases with a Mason 3 radial head fracture. Four patients had an open fracture. These comminuted ulna fractures included nine Mayo Clinic IIIB fractures. Bone fixation was performed with two third-cylinder tubular plates, one plate on each side of the proximal ulna. This allows more versatile solutions for screw insertion. Functional assessment (according to Broberg and Morrey) and radiological evaluation (bone healing) were provided at 6 months and at the longest follow-up by an independent surgeon.

RESULTS

Sixteen of 18 patients achieved bone union. No septic complications occurred and no hardware removal was required on patient request. In 67% of the cases, the Morrey score indicated excellent or good results with a mean score of 82.

DISCUSSION

There are no reports in the literature on the technical point of fixation concerning complex fractures of the ulna. Two plates mean the possibility of twice the number of screw insertions for epiphyseal reconstruction . This fixation remains easy to perform and provides stable anatomic reconstruction of the ulna.

LEVEL OF EVIDENCE

Level IV. Retrospective study.

Notch3 is a major regulator of vascular tone in cerebral and tail resistance arteries

OBJECTIVE

Notch3, a member of the evolutionary conserved Notch receptor family, is primarily expressed in vascular smooth muscle cells. Genetic studies in human and mice revealed a critical role for Notch3 in the structural integrity of distal resistance arteries by regulating arterial differentiation and postnatal maturation.

METHODS AND RESULTS

We investigated the role of Notch3 in vascular tone in small resistance vessels (tail and cerebral arteries) and large (carotid) arteries isolated from Notch3-deficient mice using arteriography. Passive diameter and compliance were unaltered in mutant arteries. Similarly, contractions to phenylephrine, KCl, angiotensin II, and thromboxane A2 as well as dilation to acetylcholine or sodium nitroprusside were unaffected. However, Notch3 deficiency induced a dramatic reduction in pressure-induced myogenic tone associated with a higher flow (shear stress)-mediated dilation in tail and cerebral resistance arteries only. Furthermore, RhoA activity and myosin light chain phosphorylation, measured in pressurized tail arteries, were significantly reduced in Notch3KO mice. Additionally, myogenic tone inhibition by the Rho kinase inhibitor Y27632 was attenuated in mutant tail arteries.

CONCLUSIONS

Notch3 plays an important role in the control of vascular mechano-transduction, by modulating the RhoA/Rho kinase pathway, with opposite effects on myogenic tone and flow-mediated dilation in the resistance circulation.

A computational model for simulating text comprehension

In the present article, we outline the architecture of a computer program for simulating the process by which humans comprehend texts. The program is based on psycholinguistic theories about human memory and text comprehension processes, such as the construction-integration model (Kintsch, 1998), the latent semantic analysis theory of knowledge representation (Landauer & Dumais, 1997), and the predication algorithms (Kintsch, 2001; Lemaire & Bianco, 2003), and it is intended to help psycholinguists investigate the way humans comprehend texts.

Unhealthy effects of atmospheric temperature and pressure on the occurrence of myocardial infarction and coronary deaths. A 10-year survey: the Lille-World Health Organization MONICA project (Monitoring trends and determinants in cardiovascular disease)

BACKGROUND

Associations between an increase in coronary heart disease occurrence and low atmospheric temperatures have been reported from mortality data and hospital admission registries. However, concomitant increases in noncardiovascular case fatality rates and selection bias of hospital cases may weaken this observation. In this study, we addressed the question of the relationships between fatal and nonfatal coronary diseases and meteorological variables in 10-year data (1985 to 1994) collected in a morbidity registry (Lille-WHO MONICA Project) monitoring 257 000 men from 25 to 64 years of age.

METHODS AND RESULTS

The impacts of atmospheric temperature (in Celsius) and pressure (in millibars) on daily rates of myocardial infarction (MI) and coronary deaths were studied. Percentages of variation of event rates according to meteorological variations were derived from the relative risks estimated with a Poisson regression model. During the 10-year longitudinal survey, 3616 events occurred. Rates of events decreased linearly with increasing atmospheric temperature. For atmospheric pressure, we detected a V-shaped relationship, with a minimum of daily event rates at 1016 mbar. A 10 degrees C decrease was associated with a 13% increase in event rates (P<0.0001); a 10-mbar decrease <1016 mbar and a 10-mbar increase >1016 mbar were associated with a 12% increase (P=0.001) and an 11% increase (P=0. 01) in event rates, respectively. These effects were independent and influenced both coronary morbidity and mortality rates, with stronger effects in older age groups and for recurrent events.

CONCLUSIONS

This longitudinal study is the first to estimate the attributable effect of meteorological variables on MI morbidity in population and strongly argues for a systematic fight against cold in cardiovascular disease prevention, particularly in older ages and after a first MI.

Long-term benefits of exercise maintenance after outpatient rehabilitation program in patients with chronic obstructive pulmonary disease

BACKGROUND

Optimal strategies to maintain short-term benefits of an initial rehabilitation program (RP) are not known. To assess the long-term effects of exercise maintenance (EM) after an initial outpatient RP, the authors conducted a prospective study.

PATIENTS AND METHODS

Fifty-eight patients with moderate to moderately severe chronic obstructive pulmonary disease who completed an initial 7-week outpatient RP were included. They were allocated into four groups according to the conditions of EM they self-selected: 15 patients received a structured EM session supervised by a physiotherapist twice a week (group A); 14 patients received a structured EM session supervised by a physiotherapist once a week (group B); 15 patients continued self EM daily at home (group C); and 14 patients did not continue EM (group D). Patients were evaluated before, immediately after, and 18 months after the initial outpatient RP. Measurements included exercise testing on a cycle ergometer and a visual analog scale to evaluate chronic dyspnea.

RESULTS

After RP, all patients exhibited improvements in maximal workload (P < 0.05) and in dyspnea (P < 0.05). Improvements in maximal workload were maintained at 18 months in patients in groups A, B, and C but these only reached significance in groups B and C (P < 0.05). On the other hand, maximal workload returned to baseline values in group D (P = 0.01) at 18 months.

CONCLUSION

Our results indicate definite benefits of EM after an initial outpatient RP compared with no EM. Daily EM at home appears to be as efficient as structured EM sessions supervised by a physiotherapist, once or twice a week, in moderate to moderately severe chronic obstructive pulmonary disease.