Food Safety, the Environment, and Trade

Distorted incentives, agricultural and trade policy reforms, national agricultural development, Agricultural and Food Policy, International Relations/Trade, F13, F14, Q17, Q18,

Subshifts, MSO Logic, and Collapsing Hierarchies

We use monadic second-order logic to define two-dimensional subshifts, or sets of colorings of the infinite plane. We present a natural family of quantifier alternation hierarchies, and show that they all collapse to the third level. In particular, this solves an open problem of [Jeandel & Theyssier 2013]. The results are in stark contrast with picture languages, where such hierarchies are usually infinite.Comment: 12 pages, 5 figures. To appear in conference proceedings of TCS 2014, published by Springe

Characterization of Muscle Spindle Afferents in the Adult Mouse Using an In Vitro Muscle-Nerve Preparation

We utilized an in vitro adult mouse extensor digitorum longus (EDL) nerve-attached preparation to characterize the responses of muscle spindle afferents to ramp-and-hold stretch and sinusoidal vibratory stimuli. Responses were measured at both room (24°C) and muscle body temperature (34°C). Muscle spindle afferent static firing frequencies increased linearly in response to increasing stretch lengths to accurately encode the magnitude of muscle stretch (tested at 2.5%, 5% and 7.5% of resting length [Lo]). Peak firing frequency increased with ramp speeds (20% Lo/sec, 40% Lo/sec, and 60% Lo/sec). As a population, muscle spindle afferents could entrain 1:1 to sinusoidal vibrations throughout the frequency (10–100 Hz) and amplitude ranges tested (5–100 µm). Most units preferentially entrained to vibration frequencies close to their baseline steady-state firing frequencies. Cooling the muscle to 24°C decreased baseline firing frequency and units correspondingly entrained to slower frequency vibrations. The ramp component of stretch generated dynamic firing responses. These responses and related measures of dynamic sensitivity were not able to categorize units as primary (group Ia) or secondary (group II) even when tested with more extreme length changes (10% Lo). We conclude that the population of spindle afferents combines to encode stretch in a smoothly graded manner over the physiological range of lengths and speeds tested. Overall, spindle afferent response properties were comparable to those seen in other species, supporting subsequent use of the mouse genetic model system for studies on spindle function and dysfunction in an isolated muscle-nerve preparation

Small union with large set of centers

Let $T\subset{\mathbb R}^n$ be a fixed set. By a scaled copy of $T$ around $x\in{\mathbb R}^n$ we mean a set of the form $x+rT$ for some $r>0$. In this survey paper we study results about the following type of problems: How small can a set be if it contains a scaled copy of $T$ around every point of a set of given size? We will consider the cases when $T$ is circle or sphere centered at the origin, Cantor set in ${\mathbb R}$, the boundary of a square centered at the origin, or more generally the $k$-skeleton ($0\le k<n$) of an $n$-dimensional cube centered at the origin or the $k$-skeleton of a more general polytope of ${\mathbb R}^n$. We also study the case when we allow not only scaled copies but also scaled and rotated copies and also the case when we allow only rotated copies

Return times, recurrence densities and entropy for actions of some discrete amenable groups

Results of Wyner and Ziv and of Ornstein and Weiss show that if one observes the first k outputs of a finite-valued ergodic process, then the waiting time until this block appears again is almost surely asymptotic to $2^{hk}$, where $h$ is the entropy of the process. We examine this phenomenon when the allowed return times are restricted to some subset of times, and generalize the results to processes parameterized by other discrete amenable groups. We also obtain a uniform density version of the waiting time results: For a process on $s$ symbols, within a given realization, the density of the initial $k$-block within larger $n$-blocks approaches $2^{-hk}$, uniformly in $n>s^k$, as $k$ tends to infinity. Again, similar results hold for processes with other indexing groups.Comment: To appear in Journal d'Analyse Mathematiqu

Quasiperiodicity and non-computability in tilings

We study tilings of the plane that combine strong properties of different nature: combinatorial and algorithmic. We prove existence of a tile set that accepts only quasiperiodic and non-recursive tilings. Our construction is based on the fixed point construction; we improve this general technique and make it enforce the property of local regularity of tilings needed for quasiperiodicity. We prove also a stronger result: any effectively closed set can be recursively transformed into a tile set so that the Turing degrees of the resulted tilings consists exactly of the upper cone based on the Turing degrees of the later.Comment: v3: the version accepted to MFCS 201

Emergency revascularization in patients with cardiogenic shock on admission: a report from the SHOCK trial and registry

Aims To determine clinical correlates and optimal treatment strategy in patients with cardiogenic shock (CS) on admission. Methods and results In SHould we emergently revascularize Occluded Coronaries in cardiogenic shocK? (SHOCK) trial and registry patients with left ventricular (LV) dysfunction (n=1053), CS on admission occurred in 26% of directly admitted patients (n=166/627). Time from myocardial infarction to CS was shorter, initial haemodynamic profile poorer, and aggressive treatment less frequent in CS on admission than in delayed CS patients. CS on admission patients constituted a smaller relative proportion (11%) of the transferred (n=48/426) when compared with the directly admitted cohort (P<0.001). In-hospital mortality was higher (75 vs. 56%; P<0.001) with more rapid death (24-h mortality 40 vs. 17%; P<0.001) in CS on admission than in delayed CS patients. Emergency revascularization reduced in-hospital mortality in CS on admission (60 vs. 82%; P=0.001) and in delayed CS patients similarly (46 vs. 62%; P<0.001; interaction P=0.25). After adjustment for clinical differences, CS on admission was an independent predictor of in-hospital mortality (P=0.008). Conclusion CS on admission patients have a worse outcome but benefit equally from emergency revascularization as delayed CS patients, emphasizing the need for rapid and direct access of CS on admission patients to facilities providing this car

The effects of the 2020–2021 Coronavirus pandemic change-event on football refereeing: evidence from the Israeli and Portuguese leagues

Upon the emergence of the 2020 Coronavirus pandemic (CP), football referees were forced to cope with the interruption of leagues and experience quarantines, with a potential threat to their physical and psychological well-being. This study examined referees’ perceptions of the CP change-event, particularly the effects on refereeing engagement and performance, in part to facilitate more effective support. For this study, an online inventory was circulated during January–February 2021 to 198 referees and assistants from Israel and Portugal, asking them to reflect on the CP in the context of their careers, and the potential effects on theirrefereeing engagement and performance. The results indicated that the CP was perceived as a moderate change-event in terms of significance, severity, and coping, although many participants didconsider it as significant. The participants indicated just a minor reduction in their refereeing quality between the 2019–2020 and the 2020–2021 seasons. The main areas affected were training on agrass field, decision-making training, and financial status. Still, refereeing instruction (conducted mainly online) improved. The behavioural effects were more forceful among the nonprofessional referees, suggesting that Referee Associations must pay closer attention to support these populations. The participants’ motivation, refereeing identity, and self-efficacy were actually improved. Finally, the absence of the crowd in matches allowed the referees to be more aware of their actions and better communicate with players and coaches, which related to better performance. These findings further emphasize the social aspect of football refereeing and the importance of having upright management and communication skills.The authors would like to thank the Israel Referee Union in the Israel Football Association, the Portuguese Referees Committee and Portugal Football School for supporting this studyinfo:eu-repo/semantics/publishedVersio