The Politics of Governance and Urban Marginality: A Camp Studies Perspective

ABSTRACT

Designed to provide temporary shelter to the displaced, in protracted refugee situations camps become places of long-term residency and undergo processes of urban change. The complex realities of protracted encampment challenge the dichotomy between the city (as a norm) and the camp (as an exception) that underpins dominant theoretical models of refugee camps. Instead, the theoretical lens of urban margins allows us to circumvent this binary and analyse the camps from the perspective of their relation to the city and the state. Rather than a specific location, this article approaches urban marginality as a condition produced by unequal power relations behind the enforcement of a particular urban order. Based on two years of ethnographic fieldwork, it draws on the case of Palestinian refugee camps in the West Bank. Unlike the majority of studies on Palestinian camps that focus either on top-down politics of exclusion or political agency of camp residents, the article examines how different actors, interests and modes of exercising power (both formal and informal) intersect in camp space and produce, as well as resist and subvert, the condition of urban marginality.     

Studies of a Murine Monoclonal Antibody Directed against DARC: Reappraisal of Its Specificity

Duffy Antigen Receptor for Chemokines (DARC) plays multiple roles in human health as a blood group antigen, a receptor for chemokines and the only known receptor for Plasmodium vivax merozoites. It is the target of the murine anti-Fy6 monoclonal antibody 2C3 which binds to the first extracellular domain (ECD1), but exact nature of the recognized epitope was a subject of contradictory reports. Here, using a set of complex experiments which include expression of DARC with amino acid substitutions within the Fy6 epitope in E. coli and K562 cells, ELISA, surface plasmon resonance (SPR) and flow cytometry, we have resolved discrepancies between previously published reports and show that the basic epitope recognized by 2C3 antibody is ²²FEDVW²⁶, with ²²F and ²⁶W being the most important residues. In addition, we demonstrated that ³⁰Y plays an auxiliary role in binding, particularly when the residue is sulfated. The STD-NMR studies performed using 2C3-derived Fab and synthetic peptide corroborated most of these results, and together with the molecular modelling suggested that ²⁵V is not involved in direct interactions with the antibody, but determines folding of the epitope backbone.     

Prevalence and Antibiotic Resistance of Campylobacter spp. in Urban and Rural Black-Headed Gulls Chroicocephalus ridibundus

EcoHealth - We investigate the role of black-headed gulls (Chroicocephalus ridibundus), an omnivorous species that is among the most likely wild bird candidates for transmission of zoonotic agents,...     

Determination of ploidy and homozygosity of carrot plants obtained from anther cultures

The purpose of the present work was to evaluate carrot plants obtained from anther cultures with respect to their ploidy and homozygosity. Ploidy was determined using flow cytometry. Homozygosity of analyzed plants was determined using isoenzymes, glucose-6-phosphate isomerase (PGI) and aspartate aminotransferase (AAT). The cytometric tests revealed that more than 90% of the carrot plants obtained from anther cultures were doubled haploid. In the initial assessment of polymorphism of the two enzymatic systems in selected androgenetic carrot plants of the cultivars: Berjo, Kazan F₁, and Splendid F₁, it was proven that 100% of those plants were homozygotes in respect to PGI and also with respect to AAT. In the second experiment, the obtained androgenetic progeny of the heterozygous donor plant of cultivar Narbonne F₁ was found to be 94% homozygotic with respect to PGI and 100% homozygotic in the case of AAT. For the androgenetic plants of the cultivar Kazan F₁, 89% of them were homozygotic with respect to AAT but PGI enzyme system did not differentiate the homozygotic and heterozygotic androgenetic progeny. These results indicated that enzyme polymorphism depends on carrot genotype, therefore, analysis of some (more than one) isozymes was necessary to confirm homozygosity of plants. PGI and AAT can be a useful tool for determining homozygosity in androgenetic carrot plants.     

Novel recombinant insulin analogue with flexible C-terminus in B chain. NMR structure of biosynthetic engineered A22G-B31K-B32R human insulin monomer in water/acetonitrile solution

A tertiary structure of recombinant A22^G-B31^K-B32^R-human insulin monomer (insulin GKR) has been characterized by ¹H, ¹³C NMR at natural isotopic abundance using NOESY, TOCSY, ¹H/¹³C-GHSQC, and ¹H/¹³C-GHSQC-TOCSY spectra. Translational diffusion studies indicate the monomer structure in water/acetonitrile (65/35 vol.%). CSI analysis confirms existence of secondary structure motifs present in human insulin standard (HIS). Both techniques allow to establish that in this solvent recombinant insulin GKR exists as a monomer. Starting from structures calculated by the program CYANA, two different refinement protocols used molecular dynamics simulated annealing with the program AMBER; in vacuum (AMBER_VC), and including a generalized Born solvent model (AMBER_GB). From these calculations an ensemble of 20 structures of lowest energy was chosen which represents the tertiary structure of studied insulin. Here we present novel insulin with added A22^G amino acid which interacts with β-turn environment resulting in high flexibility of B chain C-terminus.     

The loop-less tmCdc34 E2 mutant defective in polyubiquitination in vitro and in vivo supports yeast growth in a manner dependent on Ubp14 and Cka2

Background

The S73/S97/loop motif is a hallmark of the Cdc34 family of E2 ubiquitin-conjugating enzymes that together with the SCF E3 ubiquitin ligases promote degradation of proteins involved in cell cycle and growth regulation. The inability of the loop-less ^Δ12Cdc34 mutant to support growth was linked to its inability to catalyze polyubiquitination. However, the loop-less triple mutant (tm) Cdc34, which not only lacks the loop but also contains the S73K and S97D substitutions typical of the K73/D97/no loop motif present in other E2s, supports growth. Whether ^tmCdc34 supports growth despite defective polyubiquitination, or the S73K and S97D substitutions, directly or indirectly, correct the defect caused by the loop absence, are unknown.

Results

^tmCdc34 supports yeast viability with normal cell size and cell cycle profile despite producing fewer polyubiquitin conjugates in vivo and in vitro. The in vitro defect in Sic1 substrate polyubiquitination is similar to the defect observed in reactions with ^Δ12Cdc34 that cannot support growth. The synthesis of free polyubiquitin by ^tmCdc34 is activated only modestly and in a manner dependent on substrate recruitment to SCF^Cdc4. Phosphorylation of C-terminal serines in ^tmCdc34 by Cka2 kinase prevents the synthesis of free polyubiquitin chains, likely by promoting their attachment to substrate. Nevertheless, ^tm CDC34 yeast are sensitive to loss of the Ubp14 C-terminal ubiquitin hydrolase and DUBs other than Ubp14 inefficiently disassemble polyubiquitin chains produced in ^tm CDC34 yeast extracts, suggesting that the free chains, either synthesized de novo or recycled from substrates, have an altered structure.

Conclusions

The catalytic motif replacement compromises polyubiquitination activity of Cdc34 and alters its regulation in vitro and in vivo, but either motif can support Cdc34 function in yeast viability. Robust polyubiquitination mediated by the S73/S97/loop motif is thus not necessary for Cdc34 role in yeast viability, at least under typical laboratory conditions.     

Expression of CYP19 and CYP17 Is Associated With Leg Length,Weight, and BMI

This study investigates associations between gene expressions of aromatase (CYP19), 17α hydroxylase (CYP17), and estrogen receptors α and β and anthropometric measurements in offspring of the Michigan fish eater cohort. Leg and trunk length, height, weight, and BMI and gene expression in peripheral blood cells were measured in offspring of the Michigan fish eater cohort. The parental generation was followed between 1973 and 1991, and maternal age, height, and weight data were collected. Female offspring were contacted in 2001/2002 and followed up in 2006/2007; offspring information included age, education, reproductive history, smoking, and exercise. Gene expression was standardized against 18S ribosomal ribonucleic acid (18SrRNA) and RNA polymerase II (RNA PolII) expressions. Mixed models assessed the statistical effect of gene expression on anthropometric outcomes, accounting for multiple offspring from one mother. Anthropometric measurements and gene expression were measured in 139 female offspring. The two length and the height measurements were correlated, as were BMI and weight. CYP19 expression was correlated with the other gene expressions and both estrogen receptor expressions were associated. For every 1 unit of ΔC_t (18SrRNA ‐ CYP19) or ΔC_t (RNA PolII ‐ CYP19), BMI was increased by 0.9 (P = 0.03) and 0.87 kg/m² (P = 0.04), respectively, and weight by 2.35 kg (P = 0.03) and 2.1 kg (P = 0.03), respectively. For every 1 unit of ΔC_t (18SrRNA ‐ CYP17), leg length was increased by 0.84 cm (P = 0.04). The results suggest that CYP17 gene expression may influence growth during childhood and adolescence while CYP19 may be associated with the concurrent measures of weight and BMI.