Exploring an Infinite Space with Finite Memory Scouts

Consider a small number of scouts exploring the infinite $d$-dimensional grid with the aim of hitting a hidden target point. Each scout is controlled by a probabilistic finite automaton that determines its movement (to a neighboring grid point) based on its current state. The scouts, that operate under a fully synchronous schedule, communicate with each other (in a way that affects their respective states) when they share the same grid point and operate independently otherwise. Our main research question is: How many scouts are required to guarantee that the target admits a finite mean hitting time? Recently, it was shown that $d + 1$ is an upper bound on the answer to this question for any dimension $d \geq 1$ and the main contribution of this paper comes in the form of proving that this bound is tight for $d \in \{ 1, 2 \}$.Comment: Added (forgotten) acknowledgement

Compact Network Training for Person ReID

The task of person re-identification (ReID) has attracted growing attention in recent years leading to improved performance, albeit with little focus on real-world applications. Most SotA methods are based on heavy pre-trained models, e.g. ResNet50 (~25M parameters), which makes them less practical and more tedious to explore architecture modifications. In this study, we focus on a small-sized randomly initialized model that enables us to easily introduce architecture and training modifications suitable for person ReID. The outcomes of our study are a compact network and a fitting training regime. We show the robustness of the network by outperforming the SotA on both Market1501 and DukeMTMC. Furthermore, we show the representation power of our ReID network via SotA results on a different task of multi-object tracking

Modulating Hierarchical Self-Assembly In Thermoresponsive Intrinsically Disordered Proteins Through High-Temperature Incubation Time

The cornerstone of structural biology is the unique relationship between protein sequence and the 3D structure at equilibrium. Although intrinsically disordered proteins (IDPs) do not fold into a specific 3D structure, breaking this paradigm, some IDPs exhibit large-scale organization, such as liquid-liquid phase separation. In such cases, the structural plasticity has the potential to form numerous self-assembled structures out of thermal equilibrium. Here, we report that high-temperature incubation time is a defining parameter for micro and nanoscale self-assembly of resilin-like IDPs. Interestingly, high-resolution scanning electron microscopy micrographs reveal that an extended incubation time leads to the formation of micron-size rods and ellipsoids that depend on the amino acid sequence. More surprisingly, a prolonged incubation time also induces amino acid composition-dependent formation of short-range nanoscale order, such as periodic lamellar nanostructures. We can correlate the lamellar structures to \b{eta}-sheet formation and demonstrate similarities between the observed nanoscopic structural arrangement and spider silk. We, therefore, suggest that regulating the period of high-temperature incubation, in the one-phase regime, can serve as a unique method of controlling the hierarchical self-assembly mechanism of structurally disordered proteins.Comment: 27pages, 8 figure

Followers' Perception of Leadership Style, Organizational Commitment and Regulatory Focus, Moderated by Organizational Types

Research hypotheses assumed that a positive connection would be found between transformational leadership, on one hand, and affective commitment and focus on promotion, on the other. It was also assumed that this connection would be stronger in coercive organizations. Furthermore, the research hypotheses assumed there would be positive connections between transactional leadership, on one hand, and continuance commitment and focus on prevention, on the other; stronger in utilitarian organizations. 82 employees of coercive organizations and 80 employees of utilitarian organizations participated in this study using the MLQ questionnaire, an organizational commitment questionnaire, and a regulatory focus questionnaire. It was found that the more a leader is perceived by followers as having a transformational style, the more followers will feel affective commitment toward the organization and the more they will focus on promotion and successes. Moreover, the more a leader is perceived as a transactional leader followers will feel more continuance commitment and be more focused on preventing failures. The moderation model by type of organization was confirmed. Difference between the connections noted above in coercive organizations as compared to utilitarian organizations was found

The epidemiology of psoriatic arthritis in Israel – a population-based study

Abstract Background There is limited information on the epidemiology of psoriatic arthritis (PsA) in general and in Middle Eastern populations in particular. The aims of this study were to estimate the prevalence and incidence rates of PsA and their temporal trends in the general population in Israel. Methods In this study, a cohort of adult patients with PsA was derived from the database of Clalit Health Services (CHS), Israel’s largest health fund, with over 4.4 million members. The crude and age- and sex-standardized prevalence and incidence rates of PsA from 2006 to 2015 in the general population were calculated. The variation in PsA prevalence was assessed in relation to several demographic factors. Results Among the 2,931,199 individuals aged 18 years and older registered in the CHS database in 2015, 4490 patients had a diagnosis of PsA (322 incident cases), resulting in overall crude prevalence and incidence rates of 0.153% (95% CI 0.149%, 0.158%) and 10.9 (95% CI 9.8, 12.3) per 100,000 population, respectively. The reported prevalence of PsA in Israel has doubled between 2006 and 2015 (from 0.073% to 0.153%). In contrast, the global incidence rate remained stable, with a gradual increase in incidence among individuals aged 51 to 70 years. PsA is associated with Jewish ethnicity, high socioeconomic status, and higher body mass index. Conclusions The prevalence and incidence of PsA in Israel are within the range of previous estimates from Southern European populations. An increase in the reported prevalence of PsA was observed over the past decade in the general population in Israel

Effects of anti-TNF-α treatment on lipid profile in rheumatic diseases: an analytical cohort study

Abstract Background The aim was to assess the influence of long-term treatment with tumor necrosis factor alpha (TNF-α) inhibitors on total cholesterol (TC), triglycerides (TG), low-density lipoprotein (LDL), high-density lipoprotein (HDL), and atherogenic index (AI) in rheumatoid arthritis (RA), psoriatic arthritis (PsA), and ankylosing spondylitis (AS) patients. Methods A retrospective cohort study was conducted on RA, PsA, and AS patients treated with TNF-α inhibitors for at least 270 days between 2001 and 2011. Levels of TC, TG, LDL, and HDL and the AI were compared with baseline values at 0–6, 6–12, 12–18, and 18–24 months. Patients were further subdivided into three groups according to their HMG CoA reductase inhibitor (statin) treatment status in order to assess their effect on the results. Results The records of 311 patients (152 RA, 90 PsA, and 69 AS) were reviewed. TC and TG increased following treatment with TNF-α inhibitors, from 180.85 ± 2.12 mg/dl and 116.00 ± 3.55 mg/dl at baseline to 188.12 ± 2.35 mg/dl (p = 0.02) and 132.02 ± 4.63 mg/dl at 0–6 months (p < 0.01), respectively, and to 184.88 ± 2.09 mg/dl (p = 0.02) and 129.36 ± 4.32 mg/dl at 18–24 months (p < 0.01), respectively. AI increased following treatment with TNF-α inhibitors, from –0.032 ± 0.017 at baseline to 0.004 ± 0.019 at 18–24 months (p < 0.01). LDL decreased significantly in patients who were treated with statins before and during the entire study period, from 119.97 ± 2.86 mg/dl at baseline to 104.02 ± 3.57 mg/dl at 18–24 months (p < 0.01), in contrast to an increase in LDL values in patients who did not receive statins during the study. Conclusions TNF-α inhibitor treatment was associated with a significant increase in TC and TG levels and the AI. Adding statins to the treatment was associated with a significant decrease in LDL levels

Modification of a Single Atom Affects the Physical Properties of Double Fluorinated Fmoc-Phe Derivatives

Supramolecular hydrogels formed by the self-assembly of amino-acid based gelators are receiving increasing attention from the fields of biomedicine and material science. Self-assembled systems exhibit well-ordered functional architectures and unique physicochemical properties. However, the control over the kinetics and mechanical properties of the end-products remains puzzling. A minimal alteration of the chemical environment could cause a significant impact. In this context, we report the effects of modifying the position of a single atom on the properties and kinetics of the self-assembly process. A combination of experimental and computational methods, used to investigate double-fluorinated Fmoc-Phe derivatives, Fmoc-3,4F-Phe and Fmoc-3,5F-Phe, reveals the unique effects of modifying the position of a single fluorine on the self-assembly process, and the physical properties of the product. The presence of significant physical and morphological differences between the two derivatives was verified by molecular-dynamics simulations. Analysis of the spontaneous phase-transition of both building blocks, as well as crystal X-ray diffraction to determine the molecular structure of Fmoc-3,4F-Phe, are in good agreement with known changes in the Phe fluorination pattern and highlight the effect of a single atom position on the self-assembly process. These findings prove that fluorination is an effective strategy to influence supramolecular organization on the nanoscale. Moreover, we believe that a deep understanding of the self-assembly process may provide fundamental insights that will facilitate the development of optimal amino-acid-based low-molecular-weight hydrogelators for a wide range of applications

Tunable Self-Assembled Peptide Hydrogel Sensor for Pharma Cold Supply Chain

Defrost sensors are a crucial element for proper functioning of the pharmaceutical cold chain. In this paper, the self-assembled peptide-based hydrogels were used to construct a sensitive defrost sensor for the transportation and storage of medications and biomaterials. The turbidity of the peptide hydrogel was employed as a marker of the temperature regime. The gelation kinetics under different conditions was studied to detect various stages of hydrogel structural transitions aimed at tuning the system properties. The developed sensor can be stored at room temperature for a long period, irreversibly indicates whether the product has been thawed, and can be adjusted to a specific temperature range and detection time