A Test for Differential Flatness by Reduction to Single Input Systems

For nonlinear control systems (p inputs), we present a test for flatness. The method consists of making an initial guess for p-1 of the flat outputs, which may involve parameters still to be determined. A choice of functions of time for the p-1 outputs reduce the system to one with a single input. For single input systems the problem of flatness has been solved and thus leads to the identification of the last flat output, or to obstructions to flatness under the hypotheses. We demonstrate the method for a coupled rigid body in ℝ2 and for a single rigid body in ℝ3

A Bound on the Number of Integrators Needed to Linearize a Two-input Control System

For nonlinear control systems with two inputs we consider the problem of dynamic feedback linearization. For a restricted class of dynamic compensators that correspond to adding chains of integrators to the inputs, we give an upper bound for the order of the compensator that needs to be considered. Moreover, we show by an example that this bound is sharp

Transgene design

Transgenics are powerful mouse models to understand the biological functions of genes. This chapter gives a short overview of the requirements and considerations in designing a transgene. In addition, potential important choices that have to be made in advance for the successful designing and generating a transgenic mouse model are discussed. Methods for DNA purification for microinjection are also provided in this chapter.</p

Narratives of education and the websites of international schools

BACKGROUND: Websites of international schools contain varied narratives through which international schools tell about the education they offer. The research explored the narratives of education propagated on the websites of international schools in Singapore. The exploration of the narratives involved analysing discourse and semiotics on international schools' websites to see what curriculum ideologies and narratives of education they represent. The scrutiny involved exploring the websites to see whether the narratives of education contained therein explained how the schools adopted the five curriculum ideologies stipulated by Michael Stephen Schiro. Various aspects of discourse and the texts were examined to see what narratives of international education, in addition to the curriculum ideologies, are portrayed. The current study aimed at attaining the following research questions: What narratives are present in the websites of a selection of international schools in Singapore? What educational ideologies are present within international schools' narratives as articulated on their websites, and how do international schools communicate within such narratives about the education they offer? Methodologically, how can websites of this nature be analysed with sensitivity to narratives of education? METHODS: The research adopted a qualitative design, case study strategy, inductive approach, interpretive epistemology, and ontology. The study population comprised international schools in Singapore, where five schools and their principals were sampled through convenience and purposive technique. Primary data was collected from principals using unstructured interviews and analysed through thematic analysis. Secondary data comprised of semiotics and discourse information were collected from the websites. FINDINGS: The results disclosed that the sampled websites had not explicitly stipulated the curriculum ideologies adopted in the school. There were rich narratives on how the International Baccalaureate (IB) curriculum is delivered and how unique and different its delivery was from other schools offering the same curriculum. The learner-centred, human capital, social reconstruction, social efficiency, and scholar-academic curriculum ideologies could be deduced from the rich narratives of curriculum delivery on the website. However, there lacked explicit explanations, narratives, discourses, or semiotics on the website that either stated, explained, or illustrated any curriculum ideology adopted in the schools sampled. The analysis showed that websites are instrumental in delivering educational services in an international school as they contain a variety of narratives of education. Also, the results showed that international schools heavily rely on websites to achieve their communication and marketing agenda. CONCLUSION: The researcher concluded that discourses and semiotics on the website portrayed a range of narratives on the international education curriculum and its delivery. The investigator also concluded that websites of international schools sampled were missing narratives on the curriculum ideologies adopted. The investigator determined that international school websites focused more on narratives of marketing their international curriculum to potential international learners and securing new admissions. The investigator concluded that international schools' websites are critical avenues for portraying different narratives about the international education services, curriculum and facilities offered in the school. RECOMMENDATION: The researcher recommends further improvement by incorporating aspects that were not portrayed on the websites. Additionally, further research on the subject, especially on how websites can narrate about the school's curriculum ideologies, is needed

A Homotopy Algorithm for Approximating Geometric Distributions by Integrable Systems

In the geometric theory of nonlinear control systems, the notion of a distribution and the dual notion of codistribution play a central role. Many results in nonlinear control theory require certain distributions to be integrable. Distributions (and codistributions) are not generically integrable and, moreover, the integrability property is not likely to persist under small perturbations of the system. Therefore, it is natural to consider the problem of approximating a given codistribution by an integrable codistribution, and to determine to what extent such an approximation may be used for obtaining approximate solutions to various problems in control theory. In this note, we concentrate on the purely mathematical problem of approximating a given codistribution by an integrable codistribution. We present an algorithm for approximating an m-dimensional nonintegrable codistribution by an integrable one using a homotopy approach. The method yields an approximating codistribution that agrees with the original codistribution on an m-dimensional submanifold E_0 of R^n

Rechtsvergelijkend onderzoek constitutionele toetsing

Dit rapport doet verslag van een kort vergelijkend onderzoek, uitgevoerd in opdracht van de Minister van Binnenlandse Zaken en Koninkrijksaangelegenheden, naar de organisatie en de werking van constitutionele toetsing van formele wetten in een zestal Europese landen (België, Duitsland, Frankrijk, de Scandinavische landen en dan met name Denemarken, Noorwegen en Zweden) en Sint Maarten. Doel van het onderzoek is om uit de ervaringen met constitutionele toetsing in landen die, onder erkenning ook van onderlinge verschillen, op politiek, socio-juridisch, cultureel, en economisch vlak op Nederland lijken, lessen te trekken over de invloed van de inrichting van constitutionele toetsing op de praktijk van toetsing en op de constitutionele verhoudingen. Het rapport is als volgt opgebouwd. Deel I (p. 6 en volgende) beschrijft de achtergrond en aanleiding van de studie, legt de landenkeuze uit en zet de onderzoeksvragen uiteen. Deel II (p. 9 en volgende) bevat de landenrapporten, die alle volgens een vast stramien zijn geordend. In deel III (p. 60 en volgende) worden conclusies getrokken uit het vergelijkende onderzoek. In een eerste sectie worden vaststellingen gedaan op basis van de landenrapporten, vervolgens worden die vergelijkende conclusies vertaald naar de Nederlandse context en tot slot volgen enkele algemene opmerkingen

Nationwide Association of Surgical Performance of Minimally Invasive Esophagectomy With Patient Outcomes

IMPORTANCE: Suboptimal surgical performance is hypothesized to be associated with less favorable patient outcomes in minimally invasive esophagectomy (MIE). Establishing this association may lead to programs that promote better surgical performance of MIE and improve patient outcomes.OBJECTIVE: To investigate associations between surgical performance and postoperative outcomes after MIE.DESIGN, SETTING, AND PARTICIPANTS: In this nationwide cohort study of 15 Dutch hospitals that perform more than 20 MIEs per year, 7 masked expert MIE surgeons assessed surgical performance using videos and a previously developed and validated competency assessment tool (CAT). Each hospital submitted 2 representative videos of MIEs performed between November 4, 2021, and September 13, 2022. Patients registered in the Dutch Upper Gastrointestinal Cancer Audit between January 1, 2020, and December 31, 2021, were included to examine patient outcomes.EXPOSURE: Hospitals were divided into quartiles based on their MIE-CAT performance score. Outcomes were compared between highest (top 25%) and lowest (bottom 25%) performing quartiles. Transthoracic MIE with gastric tube reconstruction.MAIN OUTCOME AND MEASURE: The primary outcome was severe postoperative complications (Clavien-Dindo ≥3) within 30 days after surgery. Multilevel logistic regression, with clustering of patients within hospitals, was used to analyze associations between performance and outcomes.RESULTS:In total, 30 videos and 970 patients (mean [SD] age, 66.6 [9.1] years; 719 men [74.1%]) were included. The mean (SD) MIE-CAT score was 113.6 (5.5) in the highest performance quartile vs 94.1 (5.9) in the lowest. Severe postoperative complications occurred in 18.7% (41 of 219) of patients in the highest performance quartile vs 39.2% (40 of 102) in the lowest (risk ratio [RR], 0.50; 95% CI, 0.24-0.99). The highest vs the lowest performance quartile showed lower rates of conversions (1.8% vs 8.9%; RR, 0.21; 95% CI, 0.21-0.21), intraoperative complications (2.7% vs 7.8%; RR, 0.21; 95% CI, 0.04-0.94), and overall postoperative complications (46.1% vs 65.7%; RR, 0.54; 95% CI, 0.24-0.96). The R0 resection rate (96.8% vs 94.2%; RR, 1.03; 95% CI, 0.97-1.05) and lymph node yield (mean [SD], 38.9 [14.7] vs 26.2 [9.0]; RR, 3.20; 95% CI, 0.27-3.21) increased with oncologic-specific performance (eg, hiatus dissection, lymph node dissection). In addition, a high anastomotic phase score was associated with a lower anastomotic leakage rate (4.6% vs 17.7%; RR, 0.14; 95% CI, 0.06-0.31).CONCLUSIONS AND RELEVANCE: These findings suggest that better surgical performance is associated with fewer perioperative complications for patients with esophageal cancer on a national level. If surgical performance of MIE can be improved with MIE-CAT implementation, substantially better patient outcomes may be achievable.</p

Taking One Step Back in Familial Hypercholesterolemia:STAP1 Does Not Alter Plasma LDL (Low-Density Lipoprotein) Cholesterol in Mice and Humans

International audienceSTAP1, encoding for STAP1 (signal transducing adaptor family member 1), has been reported as a candidate gene associated with familial hypercholesterolemia. Unlike established familial hypercholesterolemia genes, expression of STAP1 is absent in liver but mainly observed in immune cells. In this study, we set out to validate STAP1 as a familial hypercholesterolemia gene. Approach and Results: A whole-body Stap1 knockout mouse model (Stap1 -/ - ) was generated and characterized, without showing changes in plasma lipid levels compared with controls. In follow-up studies, bone marrow from Stap1 -/ - mice was transplanted to Ldlr -/ - mice, which did not show significant changes in plasma lipid levels or atherosclerotic lesions. To functionally assess whether STAP1 expression in B cells can affect hepatic function, HepG2 cells were cocultured with peripheral blood mononuclear cells isolated from heterozygotes carriers of STAP1 variants and controls. The peripheral blood mononuclear cells from STAP1 variant carriers and controls showed similar LDLR mRNA and protein levels. Also, LDL (low-density lipoprotein) uptake by HepG2 cells did not differ upon coculturing with peripheral blood mononuclear cells isolated from either STAP1 variant carriers or controls. In addition, plasma lipid profiles of 39 carriers and 71 family controls showed no differences in plasma LDL cholesterol, HDL (high-density lipoprotein) cholesterol, triglycerides, and lipoprotein(a) levels. Similarly, B-cell populations did not differ in a group of 10 STAP1 variant carriers and 10 age- and sex-matched controls. Furthermore, recent data from UK Biobank do not show association between STAP1 rare gene variants and LDL cholesterol

Endoscopic full-thickness resection of T1 colorectal cancers:a retrospective analysis from a multicenter Dutch eFTR registry

Background Complete endoscopic resection and accurate histological evaluation for T1 colorectal cancer (CRC) are critical in determining subsequent treatment. Endoscopic full-thickness resection (eFTR) is a new treatment option for T1 CRC<2cm. We aimed to report clinical outcomes and short-term results. Methods Consecutive eFTR procedures for T1 CRC, prospectively recorded in our national registry between November 2015 and April 2020, were retrospectively analyzed. Primary outcomes were technical success and R0 resection. Secondary outcomes were histological risk assessment, curative resection, adverse events, and short-term outcomes. Results We included 330 procedures: 132 primary resections and 198 secondary scar resections after incomplete T1 CRC resection. Overall technical success, R0 resection, and curative resection rates were 87.0% (95% confidence interval [CI] 82.7%-90.3%), 85.6% (95%CI 81.2%-89.2%), and 60.3% (95%CI 54.7%-65.7%). Curative resection rate was 23.7% (95%CI 15.9%-33.6%) for primary resection of T1 CRC and 60.8% (95%CI 50.4%-70.4%) after excluding deep submucosal invasion as a risk factor. Risk stratification was possible in 99.3%. The severe adverse event rate was 2.2%. Additional oncological surgery was performed in 49/320 (15.3%), with residual cancer in 11/49 (22.4%). Endoscopic follow-up was available in 200/242 (82.6%), with a median of 4 months and residual cancer in 1 (0.5%) following an incomplete resection. Conclusions eFTR is relatively safe and effective for resection of small T1 CRC, both as primary and secondary treatment. eFTR can expand endoscopic treatment options for T1 CRC and could help to reduce surgical overtreatment. Future studies should focus on long-term outcomes