Hybrid Persistency of Excitation in Adaptive Estimation for Hybrid Systems

We propose a framework to analyze stability for a class of linear non-autonomous hybrid systems, where the continuous evolution of solutions is governed by an ordinary differential equation and the instantaneous changes are governed by a difference equation. Furthermore, the jumps are triggered by the influence of an external hybrid signal. The proposed framework builds upon a generalization of the well-known persistency of excitation (PE) and uniform observability (UO) notions to the realm of hybrid systems. That is, we establish conditions, under which, hybrid PE implies hybrid UO and, in turn, uniform exponential stability (UES) and input-to-state stability (ISS). Our proofs rely on an original statement for hybrid systems, expressed in terms of Lp bounds on the solutions. We demonstrate the utility of our results on generic adaptive estimation problems. The first one concerns the so-called gradient systems, reminiscent of the popular gradient-descent algorithm. The second one pertains to designing adaptive observers/identifiers for a class of hybrid systems that are nonlinear in the input and the output, and linear in the unknown parameters. In both cases, we illustrate through examples that the proposed hybrid framework succeeds when the classic purely continuous- or discrete-time counterparts fail.Comment: 30 pages, 6 figures. This is v2. Some corrections were added, relative to v

Low- vs High-Frequency Repetitive Transcranial Magnetic Stimulation as an Add-On Treatment for Refractory Depression

Objectives: Repetitive transcranial magnetic stimulation (rTMS) seems to be effective as an antidepressant, however, some confusion remains about the best parameters to apply and the efficacy of its association with pharmacological antidepressant treatments. Method: In a single blind randomized study 14 patients with unipolar resistant depression to one antidepressant treatment were enrolled to receive, in combination with venlafaxine (150 mg), either 20 sessions of 10 Hz rTMS (2000 pulses per session) applied over the left dorsolateral prefrontal cortex (DLPFC) or 20 sessions of 1 Hz rTMS (120 stimulations per sessions) applied over the right DLPFC. Results: A similar antidepressant effect was observed in both groups with a comparable antidepressant delay of action (2 weeks) and a comparable number of responders (MADRS < 15) after 4 weeks of daily rTMS sessions (66 vs 50%). Conclusion: Low- and high- frequency rTMS seems to be effective as an add-on treatment to venlafaxine as monotherapy in pharmacological refractory major depression (stage 1). Due to its short duration (one session of 1 Hz rTMS lasts 4 min vs 16 for 10 Hz rTMS) and its safety, low frequency rTMS may be a useful alternative treatment for patients with refractory depression

Nuevas aportaciones a la flora algal de las costas marroquíes

Nouveaux apports à la flore algale des côtes marocaines Palabras clave. Marruecos, macroalgas marinas. Mots clés. Maroc, macroalgues marine

Disrupting Pre-SMA Activity Impairs Facial Happiness Recognition: An Event-Related TMS Study

It has been suggested that the left pre-supplementary motor area (pre-SMA) could be implicated in facial emotion expression and recognition, especially for laughter/happiness. To test this hypothesis, in a single-blind, randomized crossover study, we investigated the impact of transcranial magnetic stimulation (TMS) on performances of 18 healthy participants during a facial emotion recognition task. Using a neuronavigation system based on T1-weighted magnetic resonance imaging of each participant, TMS (5 pulses, 10 Hz) was delivered over the pre-SMA or the vertex (control condition) in an event-related fashion after the presentation of happy, fear, and angry faces. Compared with performances during vertex stimulation, we observed that TMS applied over the left pre-SMA specifically disrupted facial happiness recognition (FHR). No difference was observed between the 2 conditions neither for fear and anger recognition nor for reaction times (RT). Thus, interfering with pre-SMA activity with event-related TMS after stimulus presentation produced a selective impairment in the recognition of happy faces. These findings provide new insights into the functional implication of the pre-SMA in FHR, which may rely on the mirror properties of pre-SMA neuron

Age, Growth and Mortality of Atlantic chub mackerel, Scomber colias Gmelin, 1789 in the Mediterranean Waters of Morocco

This work is a study of growth aspects and mortality of the Atlantic chub mackerel, Scomber colia, from the Mediterranean Moroccan coast. A total of 845 specimens were collected from commercial catches in M'diq Bay, whose total length ranged between 16.4 and 35.9 cm. The length-weight relationship was W = 0.0019 TL3.4527 (r = 0.97) for the whole population. The Atlantic chub mackerel displays positive allometric growth. Otolith edge analysis indicated that opaque zones were formed between April and September and translucent ones during the remaining months of the year. The oldest individuals in the sample were 5 years old for both sexes. Von Bertalanffy growth parameters estimated for this species were: L∞ = 37.30 cm, k = 0.26 year-1 and t0 = - 2.19 year. The difference in growth between sexes is not significant. The estimated natural mortality was 0.59 per year

MarineX\mathcal{X}: Design and Implementation of Unmanned Surface Vessel for Vision Guided Navigation

Marine robots, particularly Unmanned Surface Vessels (USVs), have gained considerable attention for their diverse applications in maritime tasks, including search and rescue, environmental monitoring, and maritime security. This paper presents the design and implementation of a USV named marine$\mathcal{X}$. The hardware components of marine$\mathcal{X}$ are meticulously developed to ensure robustness, efficiency, and adaptability to varying environmental conditions. Furthermore, the integration of a vision-based object tracking algorithm empowers marine$\mathcal{X}$ to autonomously track and monitor specific objects on the water surface. The control system utilizes PID control, enabling precise navigation of marine$\mathcal{X}$ while maintaining a desired course and distance to the target object. To assess the performance of marine$\mathcal{X}$, comprehensive testing is conducted, encompassing simulation, trials in the marine pool, and real-world tests in the open sea. The successful outcomes of these tests demonstrate the USV's capabilities in achieving real-time object tracking, showcasing its potential for various applications in maritime operations.Comment: accepted in ICA

Small bowel volvulus with intussusception: an unusual revelation of neuroendocrine tumor

The primary malignant tumors of the small bowel are rare, representing 1 to 1.4% of all gastrointestinal tumors. We report a case of a 33 year-old women, admitted to our emergency department of visceral  surgery for acute abdomen. The clinical examination revealed diffuse abdominal distension, defenseless, the hernia orifices were free and the rectal examination was normal. The biological test showed no hydro electrolytic disorders with normal hemoglobin and normal renal function. The abdominal CT-Scan showed signs of bowel obstruction due to a volvulus with intussusception without ischemia. The patient was operated urgently; the exploration has revealed a small bowel obstruction in the ileum with volvulus, an intussusceptum associated with a retractile mesenteritis, and the hepatic exploration found no   metastases. The patient underwent a bowel resection taking away the intussusceptum with the  infiltrated mesentery. The postoperative course was uneventful. The pathological result has proved a  well-differentiated neuroendocrine tumor with five free nodes. Through this observation, we aim to  highlight that an obstruction of small bowel with volvulus and intussusception could be exceptionally due  to a neuroendocrine tumor, this complication has enabled a relatively early diagnosis in the absence of metastases and a 6-month follow-up without recurrence is a  demonstration.Key words: Intestines, small, volvulus, intussusception, neuroendocrine tumor

Transcranial Direct Current Stimulation for Obsessive-Compulsive Disorder: A Systematic Review

Despite the advances in psychopharmacology and established psychotherapeutic interventions, more than 40% of patients with obsessive-compulsive disorder (OCD) do not respond to conventional treatment approaches. Transcranial direct current stimulation (tDCS) has been recently proposed as a therapeutic tool to alleviate treatment-resistant symptoms in patients with OCD. The aim of this review was to provide a comprehensive overview of the current state of the art and future clinical applications of tDCS in patients with OCD. A literature search conducted on the PubMed database following PRISMA guidelines and completed by a manual search yielded 12 results: eight case reports, three open-label studies (with 5, 8, and 42 participants), and one randomized trial with two active conditions (12 patients). There was no sham-controlled study. A total of 77 patients received active tDCS with a large diversity of electrode montages mainly targeting the dorsolateral prefrontal cortex, the orbitofrontal cortex or the (pre-) supplementary motor area. Despite methodological limitations and the heterogeneity of stimulation parameters, tDCS appears to be a promising tool to decrease obsessive-compulsive symptoms as well as comorbid depression and anxiety in patients with treatment-resistant OCD. Further sham-controlled studies are needed to confirm these preliminary results