Engagement of mental effort in response to mental fatigue: A psychophysiological analysis

Acute mental fatigue, characterized by a transient decline in cognitive efficiency during or following prolonged cognitive tasks, can be managed through adaptive effort deployment. In response to mental fatigue, individuals can employ two main behavioral patterns: engaging a compensatory effort to limit performance decrements, or disengaging effort, leading to performance deterioration. This study investigated the behavioral pattern used by participants in mental fatigue conditions. Fifty participants underwent a sequential-tasks protocol with counterbalanced sessions who took place in two separate sessions: a 30-min incongruent Stroop task (fatiguing session) or a 30-min documentary viewing task (control session), followed by a time-to-exhaustion (TTE) handgrip task at 13% of maximal voluntary contraction. Psychophysiological measures included the preejection period, heart rate variability, blood pressure, and respiration. Behavioral results showed deteriorated TTE handgrip performance after the Stroop task compared to after the documentary viewing task. During the Stroop task participants were more conservative and prioritized accuracy over speed. Self-reported fatigue was greater after the Stroop task. Psychophysiological data revealed a gradual decrease in sympathetic activity over time in both tasks, with the Stroop task showing a more pronounced decrease. Taken together, these findings suggest a disengagement of effort for a large proportion of participants (49%) that could be partly attributed to a habituation to the demands of the Stroop task. This study illustrates the interplay of behavioral patterns of effort investment in the context of mental fatigue and underscores the role of disengagement as a dominant response to this phenomenon among healthy participants.

Etiology of Acute Febrile Illnesses in Adults in the Defense Community in French Guiana

In tropical countries, acute febrile illnesses represent a complex clinical problem for general practitioners. We describe the prevalence of different etiologies of acute febrile illnesses occurring among French service members and their families, excluding children, in general practice in French Guiana. From June 2017 to March 2020, patients with a fever ≥37.8°C with a duration of less than 15 days who sought medical care at the army medical centers in Cayenne and Kourou were prospectively enrolled. Based on clinical presentation, blood, urine, nasopharyngeal, and stool samples were collected for diagnostic testing for viruses, bacteria, and parasites (by direct examination, microscopic examination of blood smears, culture, serology, or polymerase chain reaction), and standardized biological tests were systematically performed. Among 175 patients retained for analysis, fever with nonspecific symptoms was predominant (46.9%), with 10 Plasmodium vivax malaria cases, 8 dengue infections, and 6 cases of Q fever. The second most frequent cause of acute febrile illness was upper respiratory tract infections (32.0%) due to influenza virus (n = 18) or human rhinovirus (n = 10). Among the causes of acute febrile illness in French Guiana, clinicians should first consider arboviruses and malaria, as well as Q fever in cases of elevated C-reactive protein with nonspecific symptoms and influenza in cases of signs and symptoms associated with upper respiratory tract infections. Despite an expanded microbiological search, the etiology of 51.4% of acute febrile illnesses remain unknown. Further investigations will be necessary to identify the etiology of acute febrile illnesses, including new pathogens, in French Guiana.

Design of a fast and low-noise front-end electronics developed for the measurements of low- and medium-energy charged particles in space plasma environments

A fast and low-noise front-end electronics for amplifying and filtering the signal generated by a silicon detector has been designed, simulated, developed, and characterized as the main part of the detection chain for an instrument devoted to the measurements of low- and medium-energy charged particles in space plasma environments. The targeted low energy threshold is 10 keV with a 10% resolution. The simulated performances of the developed electronics reach a gain bandwidth of up to 16.1 GHz, a noise level at the input of 0.96 nV/Hz-1/2, and an equivalent noise charge of 4.62 keV. The experimental measurements with injection testing show resolution below 5 keV and a low threshold of 31.46 keV. Radioactive testing shows a resolution of 30.9 keV because the detector capacitance is larger than expected (21 vs 10 pF). A good agreement between simulation with a 21 pF detector capacitance and experimental measurement is achieved within 18%.

Applying cosmetic oil with added aromatic compounds improves tactile sensitivity and skin properties

Tactile sensitivity generally decreases with aging and is associated with impairments in skin properties. Products that hydrate the skin can combat touch deficits and aromatic compounds have been shown to improve skin mechanical properties. Thus, we tested a base cosmetic oil against a perfumed oil, applied to the skin of females aged 40-60 years, on tactile sensitivity and skin properties after repeated application. Tactile detection thresholds were assessed using calibrated monofilaments applied at the index finger, palm, forearm, and cheek. Spatial discrimination on the finger was assessed using pairs of plates with different inter-band spaces. These tests were performed before and after 1 month of base or perfumed oil use. We found that tactile detection thresholds and spatial discrimination improved only in perfumed oil group. A complementary immunohistological study using human skin was conducted to estimate the expression of olfactory receptor OR2A4 and elastic fiber length. Further, the expression of OR2A4 intensity and the length of elastic fibers increased significantly with oil application, where larger effects were seen with the perfumed oil. We conclude that the application of a perfumed oil may be of additional benefit and could repair, and even prevent, tactile decline with aging by ameliorating skin condition.

Dysfunctional Schemas from Preadolescence as One Major Avenue by Which Meaning Has Impact on Mental Health

A main way by which meaning influences mental health is by the formation of interpersonal schemas that specify what to expect from others and how to treat them. Particularly during preadolescence (a developmental phase focused on interpersonal skills), young people living in a stressful or hurtful environment can form atypical schemas that can help them survive but that produce serious problems when later applied to newly forming adult relationships. We provide three case studies illustrating this process. A boy learned to cope by withdrawing from social interaction and excelling in schoolwork. A girl learned to cope by denying her own needs and sacrificing herself for the welfare of others. Another girl coped by pervasive distrust of others and by becoming assertively independent. These children learned well enough to adapt to these dysfunctional relationships so as to suffer as little as possible, and they even developed some personal skills and resources. However, the rigid schemas had a destructive impact on their adult relationships. Proposals for interventions to change meaning and behaviors are discussed.

Refined high-content imaging-based phenotypic drug screening in zebrafish xenografts

Zebrafish xenotransplantation models are increasingly applied for phenotypic drug screening to identify small compounds for precision oncology. Larval zebrafish xenografts offer the opportunity to perform drug screens at high-throughput in a complex in vivo environment. However, the full potential of the larval zebrafish xenograft model has not yet been realized and several steps of the drug screening workflow still await automation to increase throughput. Here, we present a robust workflow for drug screening in zebrafish xenografts using high-content imaging. We established embedding methods for high-content imaging of xenografts in 96-well format over consecutive days. In addition, we provide strategies for automated imaging and analysis of zebrafish xenografts including automated tumor cell detection and tumor size analysis over time. We also compared commonly used injection sites and cell labeling dyes and show specific site requirements for tumor cells from different entities. We demonstrate that our setup allows us to investigate proliferation and response to small compounds in several zebrafish xenografts ranging from pediatric sarcomas and neuroblastoma to glioblastoma and leukemia. This fast and cost-efficient assay enables the quantification of anti-tumor efficacy of small compounds in large cohorts of a vertebrate model system in vivo. Our assay may aid in prioritizing compounds or compound combinations for further preclinical and clinical investigations.

BepiColombo mission confirms stagnation region of Venus and reveals its large extent

The second Venus flyby of the BepiColombo mission offer a unique opportunity to make a complete tour of one of the few gas-dynamics dominated interaction regions between the supersonic solar wind and a Solar System object. The spacecraft pass through the full Venusian magnetosheath following the plasma streamlines, and cross the subsolar stagnation region during very stable solar wind conditions as observed upstream by the neighboring Solar Orbiter mission. These rare multipoint synergistic observations and stable conditions experimentally confirm what was previously predicted for the barely-explored stagnation region close to solar minimum. Here, we show that this region has a large extend, up to an altitude of 1900 km, and the estimated low energy transfer near the subsolar point confirm that the atmosphere of Venus, despite being non-magnetized and less conductive due to lower ultraviolet flux at solar minimum, is capable of withstanding the solar wind under low dynamic pressure.

Three Pathways Into Chronic Lack of Energy as a Mental Health Complaint

Abstract. Many disturbances of physical, social, and mental health have conditions involving lack of energy, difficulty in making decisions, and low interest or motivation. Laboratory studies of willpower depletion have produced similar states in a temporary fashion. The present review uses extant literature to develop and test three theories about how temporary states of low willpower could become chronic. The first is ongoing and repeated exposure to depleting circumstances, such as caregiver fatigue, burdensome financial debts, and high-stress jobs. The second focuses on inadequate recoveries, such as poor sleep, insufficient nutrition, or unsatisfying vacations. The third invokes dispositional vulnerabilities that predispose some people to become depleted more frequently than others. A wide-ranging search for evidence concluded that the first two theories have more support than the third, though all further merit research. Additional possible contributions to chronicity are discussed, such as the emergence of vicious circles.

A plausible link between the time-on-task effect and the sequential task effect

Mental fatigue can be studied by using either the time-on-task protocol or the sequential task protocol. In the time-on-task protocol, participants perform a long and effortful task and a decrease in performance in this task is generally observed over time. In the sequential task protocol, a first effortful or control task is followed by a second effortful task. The performance in the second task is generally worse after the effortful task than after the control task. The principal aim of the present experiment is to examine the relationship between these two decrements in performance while concomitantly using a sequential task protocol and assessing the performance of the first effortful task as a function of time-on-task. We expect a positive correlation between these two decrements in performance. A total of 83 participants performed a 30-min fatiguing mental task (i.e., a modified Stroop task) or a control task followed by a time-to-exhaustion handgrip task. As expected, this protocol combining the time-on-task and sequential task protocols allowed us to observe (1) a decrease in performance over time during the Stroop task, (2) a worst performance in the handgrip task after the Stroop task by comparison to the control task, (3) a positive correlation between these two effects. The decrease in performance during the Stroop task also correlated with the subjective measures of boredom and fatigue, whereas the detrimental effect observed in the handgrip task did not. Our findings suggest that the two fatigue-related phenomena share a common mechanism but are not completely equivalent.

Magnetosphere-Ionosphere-Thermosphere Coupling Study at Jupiter Based on Juno's First 30 Orbits and Modeling Tools

The dynamics of the Jovian magnetosphere is controlled by the interplay of the planet's fast rotation, its solar-wind interaction and its main plasma source at the Io torus, mediated by coupling processes involving its magnetosphere, ionosphere, and thermosphere. At the ionospheric level, these processes can be characterized by a set of parameters including conductances, field-aligned currents, horizontal currents, electric fields, transport of charged particles along field lines including the fluxes of electrons precipitating into the upper atmosphere which trigger auroral emissions, and the particle and Joule heating power dissipation rates into the upper atmosphere. Determination of these key parameters makes it possible to estimate the net transfer of momentum and energy between Jovian upper atmosphere and equatorial magnetosphere. A method based on a combined use of Juno multi-instrument data and three modeling tools was developed by Wang et al. (2021, https://doi.org/10.1029/2021ja029469) and applied to an analysis of the first nine orbits to retrieve these parameters along Juno's magnetic footprint. We extend this method to the first 30 Juno science orbits and to both hemispheres. Our results reveal a large variability of these parameters from orbit to orbit and between the two hemispheres. They also show dominant trends. Southern current systems are consistent with the generation of a region of sub-corotating ionospheric plasma flows, while both super-corotating and sub-corotating plasma flows are found in the north. These results are discussed in light of the previous space and ground-based observations and currently available models of plasma convection and current systems, and their implications are assessed.

Evolution of military evacuation activity in French Guiana over 10 years: a retrospective observational study

BACKGROUND

Three permanent military operations are established in French Guiana. The Cayenne medical unit is a French military search and rescue unit and provides MEDEVAC and CASEVAC for ill and injured soldiers. The main objective of this study was to describe the temporal trends of its evacuation missions over 10 years. The secondary purpose was to document the means used for these missions.

METHODS

This retrospective observational study included patients who were evacuated for a medical reason or an injury during military operations in French Guiana. We collected the data from the computerised registers the medical department had stored.

RESULTS

From 1 January 2010 to 31 December 2019, 1070 patients were included, representing a median annual incidence of 115 (IQR 91-122) evacuations. Of these, 602 (59%) were evacuated by helicopter, 214 (21%) by airplane, 182 (18%) by ambulance and 19 (2%) by pirogue.Reasons for evacuation were diseases in 664 (62%) patients, non-battle injuries in 389 (36%) patients and battle injuries in 17 (2%) patients. Finally, 286 (29%) evacuations were MEDEVAC and 712 (71%) were CASEVAC.Over the years, the increasing number of evacuations reached a maximum of 183 in 2018. Helicopter evacuations, once the primary mode of evacuation, have declined proportionately in favour of other means of evacuation.

CONCLUSION

Evacuation missions by the Cayenne medical unit increased over the 10-year study period, while helicopter use decreased. This evolution is a response to the constraints of adapting military operations to fight against illegal gold mining in the Amazonian Forest. Improvement of the means and procedures allows provision of the best care to patients while ensuring the ongoing conduct of military operations.

Training Willpower: Reducing Costs and Valuing Effort

The integrative model of effortful control presented in a previous article aimed to specify the neurophysiological bases of mental effort. This model assumes that effort reflects three different inter-related aspects of the same adaptive function. First, a mechanism anchored in the salience network that makes decisions about the effort that should be engaged in the current task in view of costs and benefits associated with the achievement of the task goal. Second, a top-down control signal generated by the mechanism of effort that modulates neuronal activity in brain regions involved in the current task to filter pertinent information. Third, a feeling that emerges in awareness during effortful tasks and reflects the costs associated with goal-directed behavior. The aim of the present article is to complete this model by proposing that the capacity to exert effortful control can be improved through training programs. Two main questions relative to this possible strengthening of willpower are addressed in this paper. The first question concerns the existence of empirical evidence that supports gains in effortful control capacity through training. We conducted a review of 63 meta-analyses that shows training programs are effective in improving performance in effortful tasks tapping executive functions and/or self-control with a small to large effect size. Moreover, physical and mindfulness exercises could be two promising training methods that would deserve to be included in training programs aiming to strengthen willpower. The second question concerns the neural mechanisms that could explain these gains in effortful control capacity. Two plausible brain mechanisms are proposed: (1) a decrease in effort costs combined with a greater efficiency of brain regions involved in the task and (2) an increase in the value of effort through operant conditioning in the context of high effort and high reward. The first mechanism supports the hypothesis of a strengthening of the capacity to exert effortful control whereas the second mechanism supports the hypothesis of an increase in the motivation to exert this control. In the last part of the article, we made several recommendations to improve the effectiveness of interventional studies aiming to train this adaptive function."Keep the faculty of effort alive in you by a little gratuitous exercise every day."James (1918, p. 127).

Chronic Fatigue in Cancer, Brain Connectivity and Reluctance to Engage in Physical Activity: A Mini-Review

A large amount of evidence shows that after a cancer diagnosis, patients significantly reduce their level of physical activity. Usually, this reduction is attributed to cancer-related fatigue. However, to our knowledge, no study has clearly demonstrated that fatigue alters effort-based decision-making in cancer. This mini-review aimed to provide evidence that chronic fatigue in cancer patients causes changes in brain connectivity that impact effort-based decision-making. Indeed, three patterns of activation to compensate for dysfunctional networks have been reported: greater variability in the executive network and hyperactivation in the executive network, which account for less efficient and costly processes in the frontal cortex, and reduced deactivation in the default mode network. Nevertheless, these activation patterns are also observed with other factors, such as anticipatory stressors (worry, rumination or sleep loss), that might also cause reluctance to engage in physical activity. Effort-based decision-making involving weighing costs against benefits and physical activity interventions should increase immediate benefits to facilitate engagement in effortful activities.

[Prognostic factors of neurofibromatosis type 1-associated optic pathway gliomas in children]

INTRODUCTION

Optic pathway glioma (OPG) is a classic complication of neurofibromatosis type 1 (NF1) and can impair visual function in children with this condition. The objective of this study is to describe clinical, paraclinical and prognostic characteristics of OPG associated with NF1.

MATERIALS AND METHODS

In this retrospective observational study of children followed for OPG associated with NF1 in a University Hospital, we analyzed the ophthalmological examination, brain and orbital imaging, management and the presence of associated endocrinopathy.

RESULTS

We examined 114 children with NF1, of which 26 (22.81%) presented with OPG. Mean ages at diagnosis of NF1 and OPG were 3.83 years and 6.23 years, respectively. Mean visual acuity was 20/24.4 for the worse eye and 20/23.1 for the better eye. The RNFL (retinal nerve fiber layer) was thinner in subjects than in age-matched controls (p <0.0001). Retrochiasmal location of the OPG (DodgeC) was associated with lower binocular visual acuity than other locations and <20/32 (p=0.028); 28.03% of OPG (5 girls and 1 boy) were treated with chemotherapy, and the others were monitored; 19.23% had an associated endocrinopathy.

CONCLUSIONS

OPG complicates 22.81% of NF1 cases in our series. Our study shows that retrochiasmal location of the glioma and female sex are poor prognostic factors. It also highlights the important role of OCT, since a decrease in RNFL is statistically associated with the presence of an OPG.

Outbreak of Cutaneous Leishmaniasis among military personnel in French Guiana, 2020: Clinical, phylogenetic, individual and environmental aspects

Background

Cutaneous Leishmaniasis (CL) is endemic in French Guiana but cases are usually sporadic. An outbreak signal was issued on May 15^th 2020 with 15 suspected cases after a military training course in the rainforest. An outbreak investigation was carried out.

Methodology/Principal findings

Thirty cases were confirmed. Leishmania guyanensis was the most frequent species (90%). The most frequent presentation was ulcerative (90%). Lesions on the face and hands were frequent (40% each). Eight cases (26%) presented a poor outcome after treatment with pentamidine and required a second line with amphotericin B. Three of them required further treatments with meglumine antimoniate or miltefosine. Two spots within the training area were deemed as likely sites of contamination, due to illegal logging. The isolated Leishmania strains did not form a separate cluster. Participation in Week 13 of year 2020 was associated with infection (OR = 4.59 [1.10–19.83]; p = 0.016) while undergoing only the “Fighting” exercise was protective (OR = 0.1 [0–0.74]; p = 0.021). There was no association between infection and other risk factors at the individual level. The attack rate of Regiment B (14/105 = 13.3%) was significantly higher (OR = 4.22 [1.84–9.53], p = 0.0001) compared to Regiment A (16/507 = 3.2%). The attack rate during this training course (30/858 = 3.5%) was significantly higher (OR 2.29 [1.28–4.13]; p = 0.002) than for other missions in French Guiana during the same period (22/1427 = 1.5%).

Conclusions

This outbreak could be explained by a combination of factors: climatic conditions around week 13, at-risk activities including night trainings, absence of impregnation, a lesser experience of rainforest duties in Regiment B and illegal logging attracting sandflies on military training grounds.

Cutaneous Leishmaniasis is caused by parasites of the Leishmania genus and infects humans after a sandfly bite. Outbreaks are rare and hard to investigate in isolated tropical areas. In this study, the authors explored the different possible origins of an outbreak of cutaneous leishmaniasis among soldiers training in the rainforest of French Guiana. The outbreak occurred in March 2020. Concerning the symptoms, several patients presented resistant infections and multiple lines of treatment, raising the issue of resistant Leishmania strains. The different strains isolated during the outbreak were not genetically closed, as far as routine PCR techniques would indicate. The authors looked for individual behaviours exposing soldiers to sandfly bites but none was significantly associated with infection. The authors found two spots in the military training areas where illegal logging probably increased the density of sandflies and put service members at risk. The 13^th week of 2020 was associated to a higher risk of infection due to climatic conditions. This study shows how interactions between humans and the rainforest can increase the risk of parasitic outbreaks.

Case Report: "Killer Bee" Swarm Attacks in French Guiana: The Importance of Prompt Care

In French Guiana, a French overseas region partly located in the Amazon, "Africanized" bees, a hybrid species of Brazilian bees known as "killer bees," have been observed since 1975. Since then, several cases requiring long hospitalization times have been described, allowing for a better understanding of the physiopathological mechanisms of this particular envenomation. Here, we report on a series of 10 cases of patients simultaneously attacked by hundreds of killer bees and immediately treated by a prehospital medical team already on site. Between 75 and 650 stingers were removed per victim. The reference treatment for anaphylaxis using intramuscular injection of epinephrine, vascular filling, and oxygen therapy was administered to all patients without delay. A clinical description was provided, and biological tests were performed immediately after the envenomation. We therefore observe the existence of a two-phase, medically well-controlled systemic toxic reaction. Thus, all our patients left the hospital after 44 hours of monitoring with no complications or sequelae, despite levels of intoxication described as potentially fatal elsewhere in the literature.

Are Barriers the Same Whether I Want to Start or Maintain Exercise? A Narrative Review on Healthy Older Adults

To help older adults begin or adhere to regular physical exercise, several studies have endeavored to identify barriers to active behavior. However, there is a lack of information about barriers for active older people. In addition, most of the reviews of the literature compare only active people to inactive or sedentary people without examining in detail the barriers with respect to the degree of commitment to behavioral change. Finally, there is no consistency in the results of studies investigating the effects of barriers on the relationship between stages of change and exercise behavior. The first aim of this narrative review is to compare barriers that affect exercise stages of change from those that affect levels of exercise behavior in a healthy older population and the factors that can lead to relapse or dropout; the second aim is to identify the extent to which barriers hinder the relationships between stages of change and exercise behaviors. The results showed that barriers are well identified in sedentary people and in the first two stages of change (pre-contemplation and contemplation) compared to active seniors and other stages of change (preparation, action and maintenance). Consistency between the formulations of the different stages in comparison with the transtheoretical model and the definition of barriers and the limitations of measuring physical activity in the different studies are discussed. Finally, novel perspectives of research are proposed to address the flaws in the reviewed studies.

Coupling of melanocyte signaling and mechanics by caveolae is required for human skin pigmentation

Tissue homeostasis requires regulation of cell-cell communication, which relies on signaling molecules and cell contacts. In skin epidermis, keratinocytes secrete factors transduced by melanocytes into signaling cues promoting their pigmentation and dendrite outgrowth, while melanocytes transfer melanin pigments to keratinocytes to convey skin photoprotection. How epidermal cells integrate these functions remains poorly characterized. Here, we show that caveolae are asymmetrically distributed in melanocytes and particularly abundant at the melanocyte-keratinocyte interface in epidermis. Caveolae in melanocytes are modulated by ultraviolet radiations and keratinocytes-released factors, like miRNAs. Preventing caveolae formation in melanocytes increases melanin pigment synthesis through upregulation of cAMP signaling and decreases cell protrusions, cell-cell contacts, pigment transfer and epidermis pigmentation. Altogether, we identify that caveolae serve as molecular hubs that couple signaling outputs from keratinocytes to mechanical plasticity of pigment cells. The coordination of intercellular communication and contacts by caveolae is thus crucial to skin pigmentation and tissue homeostasis.

Impact of incidental parathyroidectomy and mediastinal-recurrent cellular and lymph-node dissection on parathyroid function after total thyroidectomy

OBJECTIVES

To determine the impact of incidental parathyroidectomy and mediastinal-recurrent cellular and lymph-node dissection on parathyroid function after total thyroidectomy.

MATERIAL AND METHODS

A single-center retrospective study was conducted for a 5-year period in a university hospital center, including 605 patients undergoing total thyroidectomy, 52 of whom had mediastinal-recurrent cellular and lymph-node dissection.

ENDPOINTS

The main endpoint was intraoperative number of parathyroid glands as predictor of parathyroid hormone (PTH) level and postoperative hypocalcemia. The secondary endpoint was the correlation between associated mediastinal-recurrent cellular and lymph-node dissection and incidental parathyroidectomy and its impact on PTH level and calcemia in the immediate postoperative period and at 1 month.

RESULTS

161 patients (26.61%) showed hypocalcemia in the immediate postoperative period and 12 (1.98%) at 1 month. Mediastinal-recurrent cellular and lymph-node dissection increased incidental parathyroidectomy risk 4.6-fold. Mediastinal-recurrent cellular and lymph-node dissection was associated with a statistically "suggestive" decrease in day-1 calcemia (P=0.03), and no significant decrease at 1 month (P=0.52). Incidental parathyroidectomy (6.7% of cases with parathyroidectomy versus 1.3% without) did not significantly increase the rate of early hypocalcemia (P=0.28), but was associated with a "suggestive" worsening at 1 month (P=0.02).

CONCLUSION

Hypocalcemia after total thyroidectomy is a complex, probably multifactorial issue. Systematic parathyroid gland identification is not recommended due to the increased risk of gland lesion, mainly by devascularization. Incidental parathyroidectomy may induce hypocalcemia at 1 month postoperatively (statistically "suggestive" association).

An Integrative Model of Effortful Control

This article presents an integrative model of effortful control, a resource-limited top-down control mechanism involved in mental tasks and physical exercises. Based on recent findings in the fields of neuroscience, social psychology and cognitive psychology, this model posits the intrinsic costs related to a weakening of the connectivity of neural networks underpinning effortful control as the main cause of mental fatigue in long and high-demanding tasks. In this framework, effort reflects three different inter-related aspects of the same construct. First, effort is a mechanism comprising a limited number of interconnected processing units that integrate information regarding the task constraints and subject’s state. Second, effort is the main output of this mechanism, namely, the effort signal that modulates neuronal activity in brain regions involved in the current task to select pertinent information. Third, effort is a feeling that emerges in awareness during effortful tasks and reflects the costs associated with goal-directed behavior. Finally, the model opens new avenues for research investigating effortful control at the behavioral and neurophysiological levels.

Analysis of diagnosis announcements in Abidjan pediatric oncology unit 2 years after introduction of the African Pediatric Cancer Announcement Guideline

INTRODUCTION

Announcing the diagnosis allows the therapeutic alliance between physicians and patients to be sealed and it prevents abandonment of treatment. To compensate for the deficit in information received by the families, the Franco-African Group of Pediatric Oncology (FAGPO) has published an "African Pediatric Cancer Announcement Guide" for the group's pediatric oncology units.

OBJECTIVE

To analyze the announcements made to parents and children 2 years after the provision of this guide.

METHODS

Cross-sectional survey conducted from March to July 2016. In total, 69 parents of children followed up in the pediatric oncology unit of Abidjan were interviewed regarding the characteristics of the announcement that was made to them and the information given to the sick child.

RESULTS

Of all the accompanying individuals, 91% reported having benefited from the announcement made with empathy, mainly by a physician. In approximately one quarter of the cases the information had been given to a third party. The main barriers to information were: the negative experiences of parents, the medical terminology, and communication problems. The sick child was rarely informed.

DISCUSSION

The information given was in accordance, in content and form, with the data from Western and African literature. The lack of information given to the child has a dual explanation: the primacy of the community over the individual advocated by African culture and the non-integration of the rights of children in the current code of ethics.

CONCLUSION

The information provided could be improved by practical training of physicians in the technique of breaking bad news to patients and their families and the use of a code of ethics in accordance with the principle of autonomy.

The exercise-cognition relationship: A virtuous circle

Exercise and health psychology have generated 2 sets of empirical studies guided by separate theory-driven axes. The first axis focuses on the causal relationship between chronic exercise and cognition and, more particularly, high-level cognitive functions such as executive functions (EFs). The second axis examines factors influencing the adherence process to physical activity (PA). Research conducted during the past decade shows that these 2 topics are closely linked, with EFs and effortful control playing a pivotal role in the bidirectional relationship linking PA and mental/brain health. The present article supports the idea that an individual engaged in the regular practice of effortful PA initiates a virtuous circle linking PA and effortful control in a bidirectional way. On the one hand, chronic exercise leads to an improvement of EFs and effortful control. On the other hand, gains in EFs and effortful control effectiveness lead to a reciprocal facilitation of the maintenance of PA over time. Some limitations and perspectives to this effort hypothesis are proposed in the last part of the article.

Localization, fate and interactions of Emilin-1 in human skin

OBJECTIVE

Emilin-1 is a versatile protein abundant in tissues where resilience and elastic recoil are prominent and interacting with components of the extracellular matrix. Still, little is known about Emilin-1 in the skin. Therefore, we investigated Emilin-1 in the skin, its localization, its fate upon ageing, its interactions with other proteins and the effect of its knockdown.

METHODS

Skin explants from young or old Caucasian women, immunofluorescently labelled by anti-Emilin-1, anti-Fibrillin-1 and anti-Elastin antibodies, were analysed using confocal microscopy. Skin explants subjected to UV-induced skin ageing were also analysed. Colocalization of Emilin-1 with Collagen IV, Fibrillin-1 and Elastin was studied by multiphoton microscopy and co-immunoprecipitation. Finally, the effect of Emilin-1 extinction was studied by producing small interfering RNA (siRNA) knockdown fibroblasts and by analysing the outcome on selected genes.

RESULTS

In skin sections from young donors, Emilin-1 localizes similarly to Elastin and Fibrillin-1. In the papillary dermis, it shows clear and ramified structures, perpendicular to the dermo-epidermal junction that are reminiscent of the oxytalan fibres. In the reticular dermis, Emilin-1 signal appears identical to that of the elastic fibres network. Upon intrinsic or UV-induced ageing, the signal associated with Emilin-1 is drastically reduced and disorganized. Multiphoton microscopy study shows that, as expected, Emilin-1 colocalizes with Elastin. It also colocalizes with Collagen IV in the basement membrane and within dermal fibroblasts. Interaction of Emilin-1 with Elastin and Collagen IV was also found by co-immunoprecipitation. It also reveals interaction with Laminin-5. Finally, siRNA-mediated knockdown of EMILIN-1 show little effect on the expression level of the 61 genes we studied. The most striking change is a downregulation of fibroblast growth factor receptor 2 that show a decrease similar to that of EMILIN-1 itself and after 8 days a downregulation of COL6A1.

CONCLUSION

In skin, Emilin-1 locates in the dermis, up to the basement membrane, interacting with components of the extracellular matrix but also with the anchoring complex. These interactions are important for cell adhesion, migration, proliferation and would suggest that Emilin-1 might be important for maintaining the 3D structure of the extracellular matrix.

Evolution of symptoms and quality of life during Zika virus infection: A 1-year prospective cohort study

BACKGROUND

Although the complications of Zika virus infection have been well described, the clinical pattern has not been reported in enough detail to differentiate this infection from those with other arboviroses, and no longitudinal study has yet been published on the persistence of symptoms and quality of life.

OBJECTIVES

were to describe bio-clinical pattern and quality of life during ZIKV infection, and their evolution.

STUDY DESIGN

We present a 1-year clinical follow-up of 49 people infected with Zika virus in French Guiana, for whom the diagnosis was confirmed by RT-PCR in serum or urine.

RESULTS

Fever was inconsistent (95% confidence interval (CI), 39-67). Exanthema (CI, 84-100) was maculopapular, with pruritus and conjunctivitis, variable over time and disappeared 12 days after the onset of symptoms (CI, 10-14). Joint pain (CI, 39-67) occurred mainly in the hands, wrists, knees and ankles and lasted for 10 days (CI, 7-13). Asthenia (CI, 61-85) scored low (3/10) but lasted for 19 days (CI, 16-22). The last two symptoms strongly limited patients' activities in the acute stage of the disease (RAPID-3 score, CI, 5-8). None of the patients had neurological complications, but 41% (CI, 27-55) had areflexia during the first month.

CONCLUSIONS

We found no real chronic evolution or decreased quality of life, function or ability to work from the first month after symptom onset.

Interaction between BDNF Polymorphism and Physical Activity on Inhibitory Performance in the Elderly without Cognitive Impairment

Background: In the elderly, physical activity (PA) enhances cognitive performances, increases brain plasticity and improves brain health. The neurotrophic hypothesis is that the release of brain-derived neurotrophic factor (BDNF), which is implicated in brain plasticity and cognition, is triggered by PA because motoneurons secrete BDNF into the bloodstream during exercise. Individual differences in cognitive performance may be explained by individual differences in genetic predisposition. A single nucleotide polymorphism on the BDNF gene, BDNFVal66Met, affects activity-dependent BDNF secretion. This study investigated the influence of the BDNFVal66Met polymorphism on the relationship between PA and controlled inhibition performance in older adults.

Methods: A total of 114 healthy elderly volunteers (mean age = 71.53 years old) were evaluated. Participants were genotyped for the BDNFVal66Met polymorphism. We evaluated inhibitory performance using choice reaction times (RT) and error rates from a Simon-like task and estimated their PA using two self-reported questionnaires. We established four groups according to PA level (active vs. inactive) and BDNFVal66Met genotype (Met carriers vs. Val-homozygous). The results were analyzed using ANOVA and ANCOVA, including age, gender and body mass index as covariates.

Results: The BDNFVal66Met polymorphism interacted with PA on controlled inhibition performance. More specifically, inactive Val-homozygous participants exhibited a lower inhibition performance than active Val homozygotes and inactive Met carriers; the former had a higher error rate without differences in RT.

Conclusion: Differences between individuals on inhibitory performance may be partially understood by the interaction between genetic influence in BDNF secretion and PA level. The results of this study clearly support the neurotrophic hypothesis that BDNF synthesis is an important mechanism underlying the influence of physical activity on brain structure and functions.

Dietary patterns in french home-living older adults: Results from the PRAUSE study

The aim of the present study was to provide descriptive dietary patterns of home-living older adults, and to examine their association with sociodemographic and 'diet-related' variables, and health and psychological factors. Dietary patterns were analyzed using separately cluster analysis for men (N=151,M_age=72.72, SD=8.80, range=56-97) and women (N=251, M_age=76.74, SD=9.95, range=55-97) in 402 older adults aged 55 years and over. Cluster analyses showed four distinct dietary profiles for each gender. In older men, the four distinct dietary clusters were associated with any differences in sociodemographic and 'diet-related' variables, cognitive function, and health and psychological factors. Likewise, in older women, the four distinct dietary clusters were associated with any differences in sociodemographic and 'diet-related' variables'. However in older women, results showed that the cluster 1 "high fish-fruit-vegetable" was associated with a better cognitive function, a better self-rated health and no depressive symptoms, whereas cluster 3 "moderate ready meals" was associated with cognitive decline, slight depression, and poor perceived health. Results emphasize the interest to take into consideration health and psychological factors associated with dietary patterns to better target the vulnerability of individuals and enable an effective prevention.

The impact of physical activity and sex differences on intraindividual variability in inhibitory performance in older adults

It is well-known that processing speed and executive functions decline with advancing age. However, physical activity (PA) has a positive impact on cognitive performances in aging, specifically for inhibition. Less is known concerning intraindividual variability (iiV) in reaction times. This study aims to investigate the influence of PA and sex differences on iiV in inhibitory performance during aging. Healthy adults were divided into active and sedentary groups according to PA level. To analyse iiV in reaction times, individual mean, standard deviation and the ex-Gaussian parameters were considered. An interaction between activity level and sex was revealed, sedentary females being slower and more variable than sedentary men. No sex differences were found in the active groups. These results indicate that the negative impact of sedentariness on cognitive performance in older age is stronger for females. The present findings underline the need to consider sex differences in active aging approaches.

In-situ thermal annealing of on-membrane silicon-on-insulator semiconductor-based devices after high gamma dose irradiation

In this paper, we investigate the recovery of some semiconductor-based components, such as N/P-type field-effect transistors (FETs) and a complementary metal-oxide-semiconductor (CMOS) inverter, after being exposed to a high total dose of gamma ray radiation. The employed method consists mainly of a rapid, low power and in situ annealing mitigation technique by silicon-on-insulator micro-hotplates. Due to the ionizing effect of the gamma irradiation, the threshold voltages showed an average shift of -580 mV for N-channel transistors, and -360 mV for P-MOSFETs. A 4 min double-cycle annealing of components with a heater temperature up to 465 °C, corresponding to a maximum power of 38 mW, ensured partial recovery but was not sufficient for full recovery. The degradation was completely recovered after the use of a built-in high temperature annealing process, up to 975 °C for 8 min corresponding to a maximum power of 112 mW, which restored the normal operating characteristics for all devices after their irradiation.

Executive functions improvement following a 5-month aquaerobics program in older adults: Role of cardiac vagal control in inhibition performance

The aims of this study were to examine the effects of aerobic exercise on measures of executive performance and their relationships with changes in cardiorespiratory fitness, cardiac vagal control (heart rate variability) and psychological variables. Thirty-six sedentary seniors aged 60-75 years were randomly assigned to a swimming and aquaerobics program or a stretching program two times a week for 21 weeks. Executive functions (inhibition, updating of working memory and cognitive flexibility) and cardiorespiratory fitness (estimated VO2max) were assessed at the start, after 10 weeks of program and at the end of the program. Resting HRV and measures of psychological outcomes (depression, self-efficacy, decisional balance) were obtained at the start and at the end of the program. Participants of both groups significantly improved their VO2max level, their psychological state and their performance for the 2-back task. Only the participants in the aquaerobics group significantly improved their vagally-mediated HRV and their performance for the Stroop test and the verbal running-span test at the end of the program. Only improvements in cardiac vagal control and in inhibition were shown to be functionally related. These results are discussed in line with the model of neurovisceral integration.

Preliminary evaluation of children treated with metronomic chemotherapy and valproic acid in a low-income country: Metro-Mali-02

BACKGROUND

Metronomics is defined by the combination of metronomic chemotherapy and drug repositioning. Since off-patent chemotherapeutic drugs can be used and given the low toxicity profile of this approach, metronomics appears to be an invaluable alternative to bring affordable targeted therapies in low-income countries.

OBJECTIVE

The aim of this study was to report on the preliminary efficacy and safety of a metronomic vincristine/cyclophosphamide/methotrexate/valproic acid regimen given to children with refractory cancer of various tumor types or with a very advanced disease.

MATERIALS AND METHODS

This prospective, single-center study evaluated the use of a metronomics protocol, consisting of a first cycle of weekly vincristine 1.5 mg/m2 (days: 1, 8, 15 and 22), daily cyclophosphamide 25 mg/m2 (days: 1-21), twice weekly methotrexate 15 mg/m² (days: 21-42) and daily valproic acid (30 mg/kg/d) followed by a 1-week break. For the following cycles, vincristine was administrated only at week 1 and 5 of the cycle. This treatment was proposed to children with refractory disease and patients who were not eligible for the protocols available in the hospital. Adverse events were determined through laboratory analyses and investigator observations.

RESULTS

From January 2010 to January 2011, 7 children (mean age: 5.4 ± 3 years old) were treated. Most frequent diagnosis was retinoblastoma. Two partial responses were observed in patients with neuroblastoma and retinoblastoma. These two patients are alive with stable disease at last follow-up (6 and 26 months, respectively) after stopping treatment.

CONCLUSION

Metronomics allows treating patients with advanced or refractory or relapsing disease and the introduction of targeted treatments in low-income countries. The potential of metronomics in children and young adults living in middle- and low-income countries warrants further larger studies.

Metronomic chemotherapy with the COMBAT regimen in advanced pediatric malignancies: a multicenter experience

BACKGROUND

The outcome of children with refractory/relapsed malignancies remains poor and novel therapies are urgently required. One of the promising approaches is metronomic chemotherapy. We present the clinical results of 74 children with advanced solid tumors treated according to treatment recommendation with data registry in three European pediatric centers.

METHODS

COMBAT (Combined Oral Metronomic Biodifferentiating Antiangiogenic Treatment) included low-dose daily temozolomide, etoposide, celecoxib, vitamin D, fenofibrate and retinoic acid. From 2004 to 2010, 74 children were enrolled.

RESULTS

The 2-year overall survival (OS) was 43.1% (median 15.4, range 1.3-69.9 months). Of the 74 patients, 50 patients (68%) died and 24 are alive: 6 (8%) with progressive disease, 7 (9%) with stable disease/partial response and 11 (15%) in complete response. Median time to response was 6 months. Of 62 patients with initially measurable disease, 25 (40%) had radiological response or stable disease. Fourteen of 25 showing clinical benefit responded within the first 6 months. The treatment was well tolerated on an outpatient basis. Regarding non-hematological toxicity of grade ≥2, hepatotoxicity of grade 3 occurred in 8 children and grade 3 cheilitis in 16 children.

CONCLUSION

COMBAT is a feasible and effective treatment option for patients with relapsing/refractory malignancies. The treatment is well tolerated with a low acute toxicity profile.

[Pulmonary sarcomatoid carcinoma: Clinical and prognostic characteristics, a case report]

Sarcomatoid carcinoma is a rare malignancy in the family of non-small-cell lung cancer. They belong to a mixed group of poorly differenciated neoplasia, including sarcomatous cells or sarcomatoid-like cells with giant or spindle cells. We report the case of a 69-year-old man with sarcomatoid carcinoma. We describe the main characteristics of these tumors. Diagnosis is frequently delayed and lesions are locally advanced. The prognostic is poorer than other non-small-cell lung cancer. Chemotherapy is often not efficient.