A global analysis of the impact of COVID-19 stay-at-home restrictions on crime

The implementation of COVID-19 stay-at-home policies was associated with a considerable drop in urban crime in 27 cities across 23 countries. More stringent restrictions over movement in public space were predictive of larger declines in crime. The stay-at-home restrictions to control the spread of COVID-19 led to unparalleled sudden change in daily life, but it is unclear how they affected urban crime globally. We collected data on daily counts of crime in 27 cities across 23 countries in the Americas, Europe, the Middle East and Asia. We conducted interrupted time series analyses to assess the impact of stay-at-home restrictions on different types of crime in each city. Our findings show that the stay-at-home policies were associated with a considerable drop in urban crime, but with substantial variation across cities and types of crime. Meta-regression results showed that more stringent restrictions over movement in public space were predictive of larger declines in crime.Peer reviewe

A Transformational Modified Markov Process for Chord-Based Algorithmic Composition

The goal of this research is to maximize chord-based composition possibilities given a relatively small amount of information. A transformational approach, based in group theory, was chosen, focusing on chord intervals as the components of a modified Markov process. The Markov process was modified to balance between average harmony, representing familiarity, and entropy, representing novelty. Uniform triadic transformations are suggested as a further extension of the transformational approach, improving the quality of tonality. The composition algorithms are demonstrated given a short chord progression and also given a larger database of albums by the Beatles. Results demonstrate capabilities and limitations of the algorithms

Antiplasmodial Properties of Acyl-Lysyl Oligomers in Culture and Animal Models of Malaria▿

Our previous analysis of antiplasmodial properties exhibited by dodecanoyl-based oligo-acyl-lysyls (OAKs) has outlined basic attributes implicated in potent inhibition of parasite growth and underlined the critical role of excess hydrophobicity in hemotoxicity. To dissociate hemolysis from antiplasmodial effect, we screened >50 OAKs for in vitro growth inhibition of Plasmodium falciparum strains, thus revealing the minimal requirements for antiplasmodial potency in terms of sequence and composition, as confirmed by efficacy studies in vivo. The most active sequence, dodecanoyllysyl-bis(aminooctanoyllysyl)-amide (C12K-2α8), inhibited parasite growth at submicromolar concentrations (50% inhibitory concentration [IC50], 0.3 ± 0.1 μM) and was devoid of hemolytic activity (<0.4% hemolysis at 150 μM). Unlike the case of dodecanoyl-based analogs, which equally affect ring and trophozoite stages of the parasite developmental cycle, the ability of various octanoyl-based OAKs to distinctively affect these stages (rings were 4- to 5-fold more sensitive) suggests a distinct antiplasmodial mechanism, nonmembranolytic to host red blood cells (RBCs). Upon intraperitoneal administration to mice, C12K-2α8 demonstrated sustainable high concentrations in blood (e.g., 0.1 mM at 25 mg/kg of body weight). In Plasmodium vinckei-infected mice, C12K-2α8 significantly affected parasite growth (50% effective dose [ED50], 22 mg/kg) but also caused mortality in 2/3 mice at high doses (50 mg/kg/day × 4)

A global analysis of the impact of COVID-19 stay-at-home restrictions on crime

The stay-at-home restrictions to control the spread of COVID-19 led to unparalleled sudden change in daily life, but it is unclear how they affected urban crime globally. We collected data on daily counts of crime in 27 cities across 23 countries in the Americas, Europe, the Middle East and Asia. We conducted interrupted time series analyses to assess the impact of stay-at-home restrictions on different types of crime in each city. Our findings show that the stay-at-home policies were associated with a considerable drop in urban crime, but with substantial variation across cities and types of crime. Meta-regression results showed that more stringent restrictions over movement in public space were predictive of larger declines in crime

Nephila clavipes spiders (Araneae: Nephilidae) keep track of captured prey counts: testing for a sense of numerosity in an orb-weaver

artículo (arbitrado) -- Universidad de Costa Rica. Escuela de Biología, 2014. Este documento es privado debido a limitaciones de derechos de autor.Nephila clavipes golden orb-web spiders accumulate prey larders on their webs and search for them if they are removed from their web. Spiders that lose larger larders (i.e., spiders that lose larders consisting of more prey items) search for longer intervals, indicating that the spiders form memories of the size of the prey larders they have accumulated, and use those memories to regulate recovery efforts when the larders are pilfered. Here, we ask whether the spiders represent prey counts (i.e., numerosity) or a continuous integration of prey quantity (mass) in their memories. We manipulated larder sizes in treatments that varied in either prey size or prey numbers but were equivalent in total prey quantity (mass). We then removed the larders to elicit searching and used the spiders’ searching behavior as an assay of their representations in memory. Searching increased with prey quantity (larder size) and did so more steeply with higher prey counts than with single prey of larger sizes. Thus, Nephila spiders seem to track prey quantity in two ways, but to attend more to prey numerosity. We discuss alternatives for continuous accumulator mechanisms that remain to be tested against the numerosity hypothesis, and the evolutionary and adaptive significance of evidence suggestive of numerosity in a sit-and-wait invertebrate predator.Universidad de Costa Rica, Escuela de Biologia UWM Graduate School Committee AwardUCR::Vicerrectoría de Docencia::Ciencias Básicas::Facultad de Ciencias::Escuela de Biologí

A miniature mimic of host defense peptides with systemic antibacterial efficacy

Oligomers of acylated lysines (OAKs) are synthetic mimics of host defense peptides (HDPs) with promising antimicrobial properties. Here we challenged the OAK concept for its ability to generate both systemically efficient and economically viable lead compounds for fighting multidrug-resistant bacteria. We describe the design and characterization of a miniature OAK composed of only 3 lysyls and 2 acyls (designated C12(ω7)K-β12) that preferentially targets gram-positive species by a bacteriostatic mode of action. To gain insight into the mechanism of action, we examined the interaction of OAK with various potential targets, including phospholipid bilayers, using surface plasmon resonance, and Langmuir monolayers, using insertion assays, epifluorescence microscopy, and grazing incidence X-ray diffraction, in a complementary manner. Collectively, the data support the notion that C12(ω7)K-β12 damages the plasma-membrane architecture similarly to HDPs, that is, following a near-classic 2-step interaction including high-affinity electrostatic adhesion and a subsequent shallow insertion that was limited to the phospholipid head group region. Notably, preliminary acute toxicity and efficacy studies performed with mouse models of infection have consolidated the potential of OAK for treating bacterial infections, including systemic treatments of methicillin-resistant Staphylococcus aureus. Such simple yet robust chemicals might be useful for various antibacterial applications while circumventing potential adverse effects associated with cytolytic compounds.—Sarig, H., Livne, L., Held-Kuznetsov, V., Zaknoon, F., Ivankin, A., Gidalevitz, D., Mor, A. A miniature mimic of host defense peptides with systemic antibacterial efficacy