Changing The Definition Of The Kilogram:Insights For Psychiatric Disease Classification

Attempts to improve fundamental definitions or classifications are not unique for psychiatry. In a 'hard science' such as metrology-the discipline of measurements in the natural sciences-a major definitional change has been proposed. In 2019, the kilogram will be redefined in terms of a constant of nature instead of a cylinder of platinum-iridium. In this article, we aim to better understand the reasons and procedures for changing definitions by studying the redefinition of the kilogram. In short, the case of the kilogram shows that 1) sometimes the rationale for a redefinition might be clear but the scientific discoveries are not available, and a vast research effort is needed to make progress, 2) progress can be made even in absence of gold standards by reference to the definitions' epistemic aims, and 3) definitions are unlikely to be final as future discoveries might lead to new definitions. These results support the current approach of ongoing, piecemeal revision of psychiatric disease classifications, and stress the importance of robust scientific evidence before changing definitions

Polynomial Time Algorithms For Some Multi-Level Lot-Sizing Problems With Production Capacities

We consider a model for a serial supply chain in which production, inventory, and transportation decisions are integrated, in the presence of production capacities and for different transportation cost functions. The model we study is a generalization of the traditional single-item economic lot-sizing model, adding stationary production capacities at the manufacturer, as well as multiple intermediate storage levels (including the retailer level), and transportation between these levels. Allowing for general concave production costs and linear holding costs, we provide polynomialtime algorithms for the cases where the transportation costs are either linear, or are concave with a fixed-charge structure. In the latter case, we make the additional common and reasonable assumption that the variable transportation and inventory costs are such that holding inventories at higher levels in the supply chain is more attractive from a variable cost perspective. The running times of the algorithms are remarkably insensitive to the number of levels in the supply chain

The long-term effect of dupilumab on chronic hand eczema in patients with moderate to severe atopic dermatitis:52 week results from the Dutch BioDay Registry

Background: The hands are a common predilection site of atopic dermatitis (AD). Dupilumab is licensed for the treatment of AD but not for chronic hand eczema (CHE), while CHE is challenging to treat. Objectives: To evaluate the long-term effect of dupilumab on hand eczema (HE) in patients with AD from the BioDay Registry. Methods: A prospective observational study of adult patients with HE, treated for AD with dupilumab. Patients with a HE severity of at least moderate at baseline were considered for analysis. Patients with other concomitantly systemic immunosuppressive treatments were excluded. Clinical effectiveness on HE severity, using the Hand Eczema Severity Index (HECSI) and photographic guide, and health-related quality of life, using the Quality of Life in Hand Eczema Questionnaire (QOLHEQ), were evaluated. Results: A total of 72 patients were included. HECSI-75 was achieved by 54/62 patients (87.1%) and HECSI-90 by 39/72 (62.9%) at 52 weeks. Based on the photographic guide, 56/62 patients (90.3%) achieved the endpoint of ‘clear’ or ‘almost clear’. Mean QOLHEQ reduction was −63.5% (95% confidence interval −38.23 to −27.41). There was no difference in response between HE subtypes. Conclusions: The results from this study hold promise for dupilumab to be a suitable treatment option for isolated CHE

Routing Trains through railway stations: model formulation and algorithms

In this paper we consider the problem of routing trains through railway stations. This problem occurs as a subproblem in a project which the authors are carrying out in cooperation with the Dutch railways. The project involves the analysis of future infrastructural capacity requirements in the Dutch railway network, Part of this project is the automatic generation and evaluation of timetables. To generate a timetable a hierarchical approach is followed: at the upper level in the hierarchy a tentative timetable is generated, taking into account the specific scheduling problems of the trains at the railway stations at an aggregate level. At the lower level in the hierarchy it is checked whether the tentative timetable is feasible with respect to the safety rules and the connection requirements at the stations. To carry out this consistency cheek, detailed schedules for the trains at the railway yards have to be generated. In this paper we present a mathematical model formulation for this detailed scheduling problem, based on the Node Packing Problem (NPP). Furthermore, we describe a solution procedure for the problem, based on a branch-and-cut approach. The approach is tested in an empirical study with data from the station of Zwolle in The Netherlands

Billiards in a general domain with random reflections

We study stochastic billiards on general tables: a particle moves according to its constant velocity inside some domain ${\mathcal D} \subset {\mathbb R}^d$ until it hits the boundary and bounces randomly inside according to some reflection law. We assume that the boundary of the domain is locally Lipschitz and almost everywhere continuously differentiable. The angle of the outgoing velocity with the inner normal vector has a specified, absolutely continuous density. We construct the discrete time and the continuous time processes recording the sequence of hitting points on the boundary and the pair location/velocity. We mainly focus on the case of bounded domains. Then, we prove exponential ergodicity of these two Markov processes, we study their invariant distribution and their normal (Gaussian) fluctuations. Of particular interest is the case of the cosine reflection law: the stationary distributions for the two processes are uniform in this case, the discrete time chain is reversible though the continuous time process is quasi-reversible. Also in this case, we give a natural construction of a chord "picked at random" in ${\mathcal D}$, and we study the angle of intersection of the process with a $(d-1)$-dimensional manifold contained in ${\mathcal D}$.Comment: 50 pages, 10 figures; To appear in: Archive for Rational Mechanics and Analysis; corrected Theorem 2.8 (induced chords in nonconvex subdomains

Diphtheria toxoid and N-trimethyl chitosan layer-by-layer coated pH-sensitive microneedles induce potent immune responses upon dermal vaccination in mice

Dermal immunization using antigen-coated microneedle arrays is a promising vaccination strategy. However, reduction of microneedle sharpness and the available surface area for antigen coating is a limiting factor. To overcome these obstacles, a layer-by-layer coating approach can be applied onto pH-sensitive microneedles. Following this approach, pH-sensitive microneedle arrays (positively charged at coating pH 5.8 and nearly uncharged at pH 7.4) were alternatingly coated with negatively charged diphtheria toxoid (DT) and N-trimethyl chitosan (TMC), a cationic adjuvant. First, the optimal DT dose for intradermal immunization was determined in a dose-response study, which revealed that low-dose intradermal immunization was more efficient than subcutaneous immunization and that the EC50 dose of DT upon intradermal immunization is 3-fold lower, as compared to subcutaneous immunization. In a subsequent immunization study, microneedle arrays coated with an increasing number (2, 5, and 10) of DT/TMC bilayers resulted in step-wise increasing DT-specific immune responses. Dermal immunization with microneedle arrays coated with 10 bilayers of DT/TMC (corresponding with ± 0.6 μg DT delivered intradermally) resulted in similar DT-specific immune responses as subcutaneous immunization with 5 μg of DT adjuvanted with aluminum phosphate (8-fold dose reduction). Summarizing, the layer-by-layer coating approach onto pH-sensitive microneedles is a versatile method to precisely control the amount of coated and dermally-delivered antigen that is highly suitable for dermal immunization.</p

Effect of dupilumab on hand eczema in patients with atopic dermatitis:An observational study

Systemic treatment options for chronic hand eczema are limited. Dupilumab is used in atopic dermatitis (AD) but is not licensed for (isolated) hand eczema. In this observational prospective study we aimed to determine the response of hand eczema to dupilumab in patients with AD. Adult patients with hand eczema and AD received dupilumab s.c. at a 600 mg loading dose, followed by 300 mg every 2 weeks. Primary outcome was a minimum improvement of 75% on the Hand Eczema Severity Index after 16 weeks (HECSI-75). Secondary outcomes were severity, measured using the Photographic guide; quality of life improvement as patient-reported outcome, measured using the Dermatology Life Quality Index (DLQI); and AD severity, measured using the Eczema Area and Severity Index (EASI). Forty-seven patients were included (32 males; mean age, 45 years). HECSI-75 was achieved by 28 (60%). Mean HECSI score reduction was 49.2 points (range, 0-164; 95% within-subject confidence interval, 46.4-52.0), which was already significantly decreased after 4 weeks (P < 0.001). DLQI score mean improvement was 8.8 points (standard deviation [SD], 6.0) or 70.0% decrease (SD, 26.4) (P < 0.001). Eighteen patients (38%) were classified as responders on the Photographic guide. There was no difference in response between chronic fissured and recurrent vesicular clinical subtypes. Similar percentages of patients achieving EASI-75 and HECSI-75 were seen after 16 weeks. In conclusion, this study shows a favorable response of hand eczema to dupilumab in patients with AD. This raises the question whether a response will also be seen in isolated hand eczema

Atomic force microscopy measurements of anionic liposomes reveal the effect of liposomal rigidity on antigen-specific regulatory T cell responses

Regulatory T cells (Tregs) are vital for maintaining a balanced immune response and their dysfunction is oftenassociated with auto-immune disorders. We have previously shown that antigen-loaded anionic liposomescomposed of phosphatidylcholine (PC) and phosphatidylglycerol (PG) and cholesterol can induce strong antigenspecificTreg responses. We hypothesized that altering the rigidity of these liposomes while maintaining theirsize and surface charge would affect their capability of inducing Treg responses. The rigidity of liposomes isaffected in part by the length and saturation of carbon chains of the phospholipids in the bilayer, and in part bythe presence of cholesterol. We used atomic force microscopy (AFM) to measure the rigidity of anionic OVA323-containing liposomes composed of different types of PC and PG, with or without cholesterol, in a molar ratio of4:1(:2) distearoyl (DS)PC:DSPG (Young's modulus (YM) 3611 ± 1271 kPa), DSPC:DSPG:CHOL(1498 ± 531 kPa), DSPC:dipalmitoyl (DP)PG:CHOL (1208 ± 538), DPPC:DPPG:CHOL (1195 ± 348 kPa),DSPC:dioleoyl (DO)PG:CHOL (825 ± 307 kPa), DOPC:DOPG:CHOL (911 ± 447 kPa), and DOPC:DOPG(494 ± 365 kPa). Next, we assessed if rigidity affects the association of liposomes to bone marrow-deriveddendritic cells (BMDCs) in vitro. Aside from DOPC:DOPG liposomes, we observed a positive correlation betweenliposomal rigidity and cellular association. Finally, we show that rigidity positively correlates with Treg responsesin vitro in murine DCs and in vivo in mice. Our findings underline the suitability of AFM to measureliposome rigidity and the importance of this parameter when designing liposomes as a vaccine delivery system

Atomic force microscopy measurements of anionic liposomes reveal the effect of liposomal rigidity on antigen-specific regulatory T cell responses

Regulatory T cells (Tregs) are vital for maintaining a balanced immune response and their dysfunction is oftenassociated with auto-immune disorders. We have previously shown that antigen-loaded anionic liposomescomposed of phosphatidylcholine (PC) and phosphatidylglycerol (PG) and cholesterol can induce strong antigenspecificTreg responses. We hypothesized that altering the rigidity of these liposomes while maintaining theirsize and surface charge would affect their capability of inducing Treg responses. The rigidity of liposomes isaffected in part by the length and saturation of carbon chains of the phospholipids in the bilayer, and in part bythe presence of cholesterol. We used atomic force microscopy (AFM) to measure the rigidity of anionic OVA323-containing liposomes composed of different types of PC and PG, with or without cholesterol, in a molar ratio of4:1(:2) distearoyl (DS)PC:DSPG (Young's modulus (YM) 3611 ± 1271 kPa), DSPC:DSPG:CHOL(1498 ± 531 kPa), DSPC:dipalmitoyl (DP)PG:CHOL (1208 ± 538), DPPC:DPPG:CHOL (1195 ± 348 kPa),DSPC:dioleoyl (DO)PG:CHOL (825 ± 307 kPa), DOPC:DOPG:CHOL (911 ± 447 kPa), and DOPC:DOPG(494 ± 365 kPa). Next, we assessed if rigidity affects the association of liposomes to bone marrow-deriveddendritic cells (BMDCs) in vitro. Aside from DOPC:DOPG liposomes, we observed a positive correlation betweenliposomal rigidity and cellular association. Finally, we show that rigidity positively correlates with Treg responsesin vitro in murine DCs and in vivo in mice. Our findings underline the suitability of AFM to measureliposome rigidity and the importance of this parameter when designing liposomes as a vaccine delivery system

Eczema control and treatment satisfaction in atopic dermatitis patients treated with dupilumab - a cross-sectional study from the BioDay registry

Background Eczema control is a new construct to be measured in atopic dermatitis (AD). Objectives Measuring patient-perceived eczema control and treatment satisfaction in AD patients, treated with dupilumab between 16 and 52 weeks. Methods Cross-sectional questionnaire study. Patients from the Dutch BioDay registry completed the Atopic Dermatitis Control Test (ADCT), Recap of Atopic Eczema (RECAP) and Treatment Satisfaction Questionnaire for Medication, Version II (TSQM v. II), along with other Patient Reported Outcome Measures (PROMs). Results 104/157 patients responded (response rate 66.2%). Median ADCT score was 4 (interquartile range [IQR] 5); median RECAP score was 5 (IQR 6); median TSQM v.II global satisfaction score was 83.3 (IQR 25.0). According to the ADCT, 38.5-66.3% perceived their AD was 'in control', depending on the interpretability method used. Minimally clinically important difference (MCID) of >= 4 points for the DLQI and POEM was achieved respectively in N = 66 (84.6%) and N = 63 (78.8%) patients. Conclusion When considering the favorable scores on other PROMs and the TSQM v. II, and comparing these to the relatively low percentage of patients perceiving control according to the ADCT, interpretability of eczema control still appears difficult. Treatment satisfaction in the studied cohort was high