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Research Summary This paper studies the impact of the COVID‐19 pandemic and the subsequent lockdown on criminal activity in the City of Buenos Aires, Argentina. Following quarantine restrictions, we find a large, significant, robust, and immediate decline in property crime reported to official agencies, police arrests, and crime reported in victimization surveys. We observe no significant change in homicides, and a significant increase in arrests for “resistance to authorities”. The decrease in criminal activity was greater in business and transportation areas, but still large in commercial and residential areas (including informal settlements). After the sharp and immediate fall, crime recovered but, by the end of 2020, it had not reached its initial levels. The arrest data additionally shows a reduction in the distance from the detainee's address to the crime location, and a fall in the number of detainees from outside the City of Buenos Aires. Crime became more local as mobility was restricted. Policy Implications We find no evidence that the reduction in the number of detainees from outside the City of Buenos Aires led to a displacement of crimeto suburban areas. This result aligns with the hypothesis that focalized place‐based interventions have the potential to reduce overall crime rates. Moreover, the increase in arrests for "resistance to authorities" at the checkpoints set up during the lockdown shows that the enforcement of mobility restrictions can cause frictions between citizens and police, negatively affecting police's legitimacy. We also find that the increased government presence for the provision of health and social services in informal settlements during the pandemic led, as a positive externality, to an additional decrease in crime.

Clathrin mediated endocytosis is a fundamental transport pathway that depends on numerous protein-protein interactions. Testing the importance of the adaptor protein-clathrin interaction for coat formation and progression of endocytosis in vivo has been difficult due to experimental constrains. Here we addressed this question using the yeast clathrin adaptor Sla1, which is unique in showing a cargo endocytosis defect upon substitution of three amino acids in its clathrin-binding motif (sla1(AAA)) that disrupt clathrin binding. Live cell imaging showed an impaired Sla1-clathrin interaction causes reduced clathrin levels but increased Sla1 levels at endocytic sites. Moreover, the rate of Sla1 recruitment was reduced indicating proper dynamics of both clathrin and Sla1 depend on their interaction. sla1(AAA) cells showed a delay in progression through the various stages of endocytosis. The Arp2/3-dependent actin polymerization machinery was present for significantly longer time before actin polymerization ensued, revealing a link between coat formation and activation of actin polymerization. Ultimately, in sla1(AAA) cells a larger than normal actin network was formed, dramatically higher levels of various machinery proteins other than clathrin were recruited, and the membrane profile of endocytic invaginations was longer. Thus, the Sla1-clathrin interaction is important for coat formation, regulation of endocytic progression, and membrane bending.

The formation of the melanosome – the organelle responsible for synthesizing the melanin pigment found in hair, skin, and eyes – has long been studied as a model for the specialized development of organelles. In part this is due to the relative ease in identifying genes that impact pigmentation based on subtle to severe forms of albinism. The melanosome belongs to a family of lysosome-related organelles (LROs) that share some characteristics including an acidic lumen, part of their protein content, and biogenesis mechanisms. This article is protected by copyright. All rights reserved.

We previously showed that cocaine self-administration increases spine density in CA1 hippocampal neurons in Lewis (LEW) but not in Fischer 344 (F344) rats. Dendritic spine morphology is intimately related to its function. Thus, we conducted a 3D morphological analysis of CA1 dendrites and dendritic spines in these two strains of rats. Strain-specific differences were observed prior to cocaine self-administration: LEW rats had significantly larger dendritic diameters but lower spine density than the F344 strain. After cocaine self-administration, proximal dendritic volume, dendritic surface area and spine density were increased in LEW rats, where a higher percentage of larger spines were also observed. In addition, we found a strong positive correlation between dendritic volume and spine morphology, and a moderate correlation between dendritic volume and spine density in cocaine self-administered LEW rats, an effect that was not evident in any other condition. By contrast, after cocaine self-administration, F334 rats showed decreased spine head volumes. Our findings suggest that genetic differences could play a key role in the structural plasticity induced by cocaine in CA1 pyramidal neurons. These cocaine-induced alterations could be related to differences in the memory processing of drug reward cues that could potentially explain differential individual vulnerability to cocaine addiction.

During clathrin-mediated endocytosis (CME), actin assembly provides force to drive vesicle internalization. Members of the Wiskott-Aldrich syndrome protein (WASP) family play a fundamental role stimulating actin assembly. WASP family proteins contain a WH2 motif that binds globular actin (G-actin) and a central-acidic motif that binds the Arp2/3 complex, thus promoting the formation of branched actin filaments. Yeast WASP (Las17) is the strongest of five factors promoting Arp2/3-dependent actin polymerization during CME. It was suggested that this strong activity may be caused by a putative second G-actin-binding motif in Las17. Here, we describe the in vitro and in vivo characterization of such Las17 G-actin-binding motif (LGM) and its dependence on a group of conserved arginine residues. Using the yeast two-hybrid system, GST-pulldown, fluorescence polarization and pyrene-actin polymerization assays, we show that LGM binds G-actin and is necessary for normal Arp2/3-mediated actin polymerization in vitro. Live-cell fluorescence microscopy experiments demonstrate that LGM is required for normal dynamics of actin polymerization during CME. Further, LGM is necessary for normal dynamics of endocytic machinery components that are recruited at early, intermediate and late stages of endocytosis, as well as for optimal endocytosis of native CME cargo. Both in vitro and in vivo experiments show that LGM has relatively lower potency compared to the previously known Las17 G-actin-binding motif, WH2. These results establish a second G-actin-binding motif in Las17 and advance our knowledge on the mechanism of actin assembly during CME.

The Lewis (LEW) and Fischer 344 (F344) inbred rat strains are frequently used to study the role of genetic factors in vulnerability to drug addiction and relapse. Glutamate and γ-amino butyric acid (GABA) transmission are significantly altered after cocaine-induced reinstatement, although whether LEW and F344 rats differ in their accumbal glutamate and GABA responsiveness to cocaine-induced reinstatement remains unknown. To investigate this, we measured by in vivo microdialysis extracellular glutamate and GABA levels in the core division of the nucleus accumbens after extinction of cocaine self-administration and during cocaine-induced reinstatement (7.5mg/kg, i.p.) in these two strains of rats. No strain differences were evident in cocaine self-administration or extinction behavior, although cocaine priming did induce a higher rate of lever pressing in LEW compared with F344 rats. After extinction, F344 rats that self-administered cocaine had less GABA than the saline controls, while the glutamate levels remained constant in both strains. There was more accumbal glutamate after cocaine priming in LEW rats that self-administered cocaine, while GABA levels were unaffected. By contrast, GABA increased transiently in F344 rats that self-administered cocaine, while glutamate levels were unaltered. In F344 saline controls, cocaine priming provoked contrasting effects in glutamate and GABA levels, inducing a delayed increase in glutamate and a delayed decrease in GABA levels. These amino acids were unaffected by cocaine priming in LEW saline rats. Together, these results suggest that genetic differences in cocaine-induced reinstatement reflect different responses of the accumbal GABA and glutamate systems to cocaine priming.

We have fabricated polystyrene opals by vertical deposition with colloidal spheres of 419 nm in diameter. Different parameters such as the concentration, temperature and relative humidity have been systematically varied in order to study the dependence of the crystalline quality of the opals on these parameters. The opals have been optically and structurally characterized, paying particular attention to the size and distribution of the domains for each fabrication condition. We have noticed a dependence of the size of the domains on the thickness which corroborates a previous study. From these results we can conclude that the characterization of the homogeneity of the thickness of the opals can be done just by using microscopy. We also report a dependence of the order of the opals on relative humidity and a selective adhesion of the opals to the substrate depending on concentration and surface chemistry. (© 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Since the early 1990's, grapefruit juice has been implicated in drug interaction with various furanocoumarins (FCs) now associated with the effect. Although FCs are present in various fruits and vegetables, it is their presence in grapefruit that has attracted the most attention. Studies have shown that FCs in grapefruit juice can vary significantly and from multiple causes. Most of all, FCs are stress-induced molecules, their levels affected by many factors ranging from UV exposure to insect infestation. There are also varietal and seasonal factors. In this study, juice processing and storage parameters were investigated. Prolonged fruit storage prior to processing and most steps involved in juice processing had little influence on the levels of 6',7'-dihydroxybergamottin (DHB), paradisin C, or bergamottin. However, products that were hot filled or stored at room temperature had lower amounts of DHB and paradisin C and higher amounts of bergaptol compared to juices that were not hot filled and stored at refrigerated temperatures. Both DHB and paradisin C are potent CYP3A4 inhibitors, while bergaptol is a very weak inhibitor. Bergamottin amounts decreased to a lesser extent. Therefore, grapefruit juice products that were hot filled or have been stored at room temperature for an extended period of time will have a reduced drug interaction potential.

Adaptor proteins play important endocytic roles including recognition of internalization signals in transmembrane cargo. Sla1p serves as the adaptor for uptake of transmembrane proteins containing the NPFxD internalization signal, and is essential for normal functioning of the actin cytoskeleton during endocytosis. The Sla1p homology domain 1 (SHD1) within Sla1p is responsible for recognition of the NPFxD signal. This study presents the NMR structure of the NPFxD-bound state of SHD1 and a model for the protein-ligand complex. The alpha+beta structure of the protein reveals an SH3-like topology with a solvent-exposed hydrophobic ligand binding site. NMR chemical shift perturbations and effects of structure-based mutations on ligand binding in vitro define residues that are key for NPFxD binding. Mutations that abolish ligand recognition in vitro also abolish NPFxD-mediated receptor internalization in vivo. Thus, SHD1 is a novel functional domain based on SH3-like topology, which employs a unique binding site to recognize the NPFxD endocytic internalization signal. Its distant relationship with the SH3 fold endows this superfamily with a new role in endocytosis.

Hermansky-Pudlak syndrome (HPS) defines a group of at least seven autosomal recessive disorders characterized by albinism and prolonged bleeding. These manifestations arise from defects in the biogenesis of lysosome-related organelles, including melanosomes and platelet dense granules. Most genes associated with HPS in humans and rodent models of the disease encode components of multisubunit protein complexes that are expressed ubiquitously and play roles in intracellular protein trafficking and/or organelle distribution. A small GTPase of the Rab family, Rab38, is also implicated in the pathogenesis of the disease. This article reviews recent progress toward elucidating the cellular functions of these proteins.

Hermansky–Pudlak syndrome (HPS) defines a group of at least seven autosomal recessive disorders characterized by albinism and prolonged bleeding due to defects in the lysosome-related organelles, melanosomes and platelet-dense granules, respectively. Most HPS genes, including HPS3, HPS5 and HPS6, encode ubiquitously expressed novel proteins of unknown function. Here, we report the biochemical characterization of a stable protein complex named Biogenesis of Lysosome-related Organelles Complex-2 (BLOC-2), which contains the HPS3, HPS5 and HPS6 proteins as subunits. The endogenous HPS3, HPS5 and HPS6 proteins from human HeLa cells coimmunoprecipitated with each other from crude extracts as well as from fractions resulting from size-exclusion chromatography and density gradient centrifugation. The native molecular mass of BLOC-2 was estimated to be 340 ± 64 kDa. As inferred from the biochemical properties of the HPS6 subunit, BLOC-2 exists in a soluble pool and associates to membranes as a peripheral membrane protein. Fibroblasts deficient in the BLOC-2 subunits HPS3 or HPS6 displayed normal basal secretion of the lysosomal enzyme β-hexosaminidase. Our results suggest a common biological basis underlying the pathogenesis of HPS-3, -5 and -6 disease.

We have investigated the temperature and carrier density dependence of the carrier capture time of two optically pumped InGaN/GaN multiple quantum well laser structures by subpicosecond time-resolved differential transmission spectroscopy. We find that the carrier capture time varies significantly with both the temperature and the carrier density. The carrier density dependence is consistent with screening of piezoelectric fields, in agreement with theoretical predictions. The sample with the lower threshold for stimulated emission has a faster carrier capture rate, which highlights the importance of carrier capture for the lasing process. At room temperature the capture time is less than 1.2 ps in both samples.

This article describes the development of optical pyrometry (OP) as a new analytical technique for the continuous monitoring of the progress of both free-radical and cationic photopolymerizations. The method is rapid, reproducible, and very easy to implement. A temperature profile of a photopolymerization can be obtained. Preliminary studies have shown that the temperatures of some polymerizing monomers can easily reach temperatures in excess of 250 °C. The effects of the mass and reactivity of the monomer, light intensity, structures, and concentrations of the photoinitiators and monomers as well as the presence or absence of oxygen on various free-radical and cationic photopolymerizations were examined with this method. Coupling of real-time infrared spectroscopy with OP provides a convenient method for simultaneously monitoring both the chemical conversion and the temperature of a photopolymerization. This combined technique affords new insights into the effects of temperature-induced autoacceleration on the course of photopolymerizations.

We report the biochemical characterization of calhepatin, a calcium-binding protein of the S100 family, isolated from lungfish (Lepidosiren paradoxa) liver. The primary structure, determined by Edman degradation and MS/MS, shows that the sequence identities with the other members of the family are lower than those between S100 proteins from different species. Calhepatin is composed of 75 residues and has a molecular mass of 8670 Da. It is smaller than calbindin D(9k) (78 residues), the smallest S100 described so far. Sequence analysis and molecular modelling predict the two EF-hand motifs characteristic of the S100 family. Metal-binding properties were studied by a direct 45Ca2+-binding assay and by fluorescence titration. Calhepatin binds Ca2+ and Cu2+ but not Zn2+. Cu2+ binding does not change the affinity of calhepatin for Ca2+. Calhepatin undergoes a conformational change upon Ca2+ binding as shown by the increase in its intrinsic fluorescence intensity and lambda(max), the decrease in the apo-calhepatin hydrodynamic volume, and the Ca2+-dependent binding of the protein to phenyl-Superose. Like most S100 proteins, calhepatin tends to form noncovalently associated dimers. These data suggest that calhepatin is probably involved in Ca2+-signal transduction.

Pasteurised orange juices and two types of commercial orange juice from frozen concentrate were differentiated based on the combined levels of 15-25 volatile constituents monitored in each of 44 juice samples. Multivariate analysis programs were used to calculate discriminant and principal component analyses and to display the results graphically. Since this group of samples was part of a nutritional database study, other parameters were included in an effort to improve discrimination of the types of juice samples monitored. Addition of °Brix and acid values improved the separation by principal component analysis of the three types of juice studied. Discriminant analysis provided better separation of juice types than did principal component analysis.

Up until now, the primary structure of fatty-acid-binding proteins (FABPs) from the livers of four mammalian (rat, human, cow and pig) and three nonmammalian (chicken, catfish and iguana) species has been determined. Based on amino acid sequence comparisons, it has been suggested that mammalian and nonmammalian liver FABPs may be paralogous proteins that originated by gene duplication, rather than as a consequence of mutations of the same gene. In this paper we report the isolation and amino acid sequence determination of two FABPs from axolotl (Ambistoma mexicanum) liver. One of them is similar to mammalian liver FABPs (L-FABPs) and the other to chicken, catfish and iguana liver FABPs (Lb-FABPs). The finding of both L-FABP and Lb-FABP in a single species, as reported here, indicates that they are paralogous proteins. The time of divergence of these two liver FABP types is estimated to be of ≈ 694 million years ago. The ligand-binding properties of axolotl liver FABPs were studied by means of parinaric-acid-binding and parinaric-acid-displacement assays. L-FABP binds two fatty acids per molecule but Lb-FABP displays a fatty-acid-conformation-dependent binding stoichiometry; L-FABP shows a higher affinity for fatty acids, especially oleic acid, while Lb-FABP has a higher affinity for other hydrophobic ligands, especially retinoic acid. In addition, the tissue-expression pattern is different, L-FABP is present in liver and intestinal mucosa while the expression of Lb-FABP is restricted to liver. Data indicate distinct functional properties of both liver FABP types.

Characterization of the properties of young brown dwarfs are important to constraining the formation of objects at the extreme low-mass end of the IMF. While young brown dwarfs share many properties with solar-mass T Tauri stars, differences may be used as tests of how the physics of accretion/outflow and disk chemistry/dissipation depend on the mass of the central object. This article summarizes the presentations and discussions during the splinter session on 'Disks, accretion and outflows of brown dwarfs' held at the CoolStars17 conference in Barcelona in June 2012. Recent results in the field of brown dwarf disks and outflows include the determination of brown dwarf disk masses and geometries based on Herschel far-IR photometry (70-160 um), accretion properties based on X-Shooter spectra, and new outflow detections in the very low-mass regime., Proceding article of the CoolStars 17 conference (June 2012, Barcelona); Summary of splinter session on 'Disks, accretion and outflows of brown dwarfs'; minor changes (update of references, language)

Grapefruit juice and grapefruit pulp wash were ultrafiltered and debittered with a pilot system. The flow rate through the membrane increased with the transmembrane pressure up to 137.8 kPa. Limonin in grapefruit juice and grapefruit pulp wash was completely removed. The debittering process was tested at 13, 27 and 48°C. Limonin removal efficiency was independent of temperature between 13 and 48°C. However the resin column was exhausted more rapidly for na-ringin, narirutin, hesperidin, and neohesperidin particularly at 13°C. Taste panel results suggested that debittering of grapefruit pulp wash appreciably increased its flavor acceptability.