Picturing women,class, and community in Arab Detroit: The strange case of Eva Habib

This essay explores the on‐going struggle to reveal and conceal the image of Eva Habib, an Arab American woman who worked in a Detroit factory and was photographed in her coveralls circa 1925. Eva's image has been a source of controversy in Detroit's Arab community since it first became public in the 1980s. I chart the evolution of this controversy, examine the interests of the parties involved, and draw conclusions about how this controversial image simultaneously undermines and reinforces popular notions of women, work, and class among Arab Americans.     

Cytokinins and shoot development

Cytokinins promote the unfolding of a complex gene expression program in tissue culture that results in the formation of shoots. Much has been learned about cytokinin signaling in the past few years; the challenge now is to understand how known steps in cytokinin signaling interface with the process of shoot development in culture and in planta. Several ways have been found to block or bypass the requirement for cytokinins, and these findings have revealed key control steps in the shoot development process. Plant control is exercised not only in the promotion of shoot development, but also in its restraint under conditions where shoots are not ordinarily formed.     

Nuf2 and Hec1 are required for retention of the checkpoint proteins Mad1 and Mad2 to kinetochores

Members of the Ndc80/Nuf2 complex have been shown in several systems to be important in formation of stable kinetochore-microtubule attachments and chromosome alignment in mitosis. In HeLa cells, we have shown that depletion of Nuf2 by RNA interference (RNAi) results in a strong prometaphase block with an active spindle checkpoint, which correlates with low but detectable Mad2 at kinetochores that have no or few stable kinetochore microtubules. Another RNAi study in HeLa cells reported that Hec1 (the human Ndc80 homolog) is required for Mad1 and Mad2 binding to kinetochores and that kinetochore bound Mad2 does not play a role in generating and maintaining the spindle assembly checkpoint. Here, we show that depletion of either Nuf2 or Hec1 by RNAi in HeLa cells results in reduction of both proteins at kinetochores and in the cytoplasm. Mad1 and Mad2 concentrate at kinetochores in late prophase/early prometaphase but become depleted by 5-fold or more over the course of the prometaphase block, which is Mad2 dependent. The reduction of Mad1 and Mad2 is reversible upon spindle depolymerization. Our observations support a model in which Nuf2 and Hec1 function to prevent microtubule-dependent stripping of Mad1 and Mad2 from kinetochores that have not yet formed stable kinetochore-microtubule attachments.     

Molecular Evidence for Gender Differences in the Migratory Behaviour of a Small Seabird

Molecular sexing revealed an unexpectedly strong female bias in the sex ratio of pre-breeding European Storm Petrels (Hydrobates pelagicus), attracted to playback of conspecific calls during their northwards migration past SW Europe. This bias was consistent across seven years, ranging from 80.8% to 89.7% female (mean annual sex ratio ± SD = 85.5% female ±4.1%). The sex ratio did not differ significantly from unity (i.e., 50% female) among (i) Storm Petrel chicks at a breeding colony in NW France, (ii) adults found dead on beaches in Southern Portugal, (iii) breeding birds attending nest burrows in the UK, captured by hand, and (iv) adults captured near a breeding colony in the UK using copies of the same sound recordings as used in Southern Europe, indicating that females are not inherently more strongly attracted to playback calls than males. A morphological discriminant function analysis failed to provide a good separation of the sexes, showing the importance of molecular sexing for this species. We found no sex difference in the seasonal or nocturnal timing of migration past Southern Europe, but there was a significant tendency for birds to be caught in sex-specific aggregations. The preponderance of females captured in Southern Europe suggests that the sexes may differ in migration route or in their colony-prospecting behaviour during migration, at sites far away from their natal colonies. Such differences in migration behaviour between males and females are poorly understood but have implications for the vulnerability of seabirds to pollution and environmental change at sea during the non-breeding season.     

Towards Regional,Error-Bounded Landscape Carbon Storage Estimates for Data-Deficient Areas of the World

Monitoring landscape carbon storage is critical for supporting and validating climate change mitigation policies. These may be aimed at reducing deforestation and degradation, or increasing terrestrial carbon storage at local, regional and global levels. However, due to data-deficiencies, default global carbon storage values for given land cover types such as ‘lowland tropical forest’ are often used, termed ‘Tier 1 type’ analyses by the Intergovernmental Panel on Climate Change (IPCC). Such estimates may be erroneous when used at regional scales. Furthermore uncertainty assessments are rarely provided leading to estimates of land cover change carbon fluxes of unknown precision which may undermine efforts to properly evaluate land cover policies aimed at altering land cover dynamics. Here, we present a repeatable method to estimate carbon storage values and associated 95% confidence intervals (CI) for all five IPCC carbon pools (aboveground live carbon, litter, coarse woody debris, belowground live carbon and soil carbon) for data-deficient regions, using a combination of existing inventory data and systematic literature searches, weighted to ensure the final values are regionally specific. The method meets the IPCC ‘Tier 2’ reporting standard. We use this method to estimate carbon storage over an area of33.9 million hectares of eastern Tanzania, reporting values for 30 land cover types. We estimate that this area stored 6.33 (5.92–6.74) Pg C in the year 2000. Carbon storage estimates for the same study area extracted from five published Africa-wide or global studies show a mean carbon storage value of ∼50% of that reported using our regional values, with four of the five studies reporting lower carbon storage values. This suggests that carbon storage may have been underestimated for this region of Africa. Our study demonstrates the importance of obtaining regionally appropriate carbon storage estimates, and shows how such values can be produced for a relatively low investment.     

Rapid identification of bio-molecules applied for detection of biosecurity agents using rolling circle amplification

Detection and identification of pathogens in environmental samples for biosecurity applications are challenging due to the strict requirements on specificity, sensitivity and time. We have developed a concept for quick, specific and sensitive pathogen identification in environmental samples. Target identification is realized by padlock- and proximity probing, and reacted probes are amplified by RCA (rolling-circle amplification). The individual RCA products are labeled by fluorescence and enumerated by an instrument, developed for sensitive and rapid digital analysis. The concept is demonstrated by identification of simili biowarfare agents for bacteria (Escherichia coli and Pantoea agglomerans) and spores (Bacillus atrophaeus) released in field.     

A Highlights from MBoC Selection: Cdc42p regulation of the yeast formin Bni1p mediated by the effector Gic2p

Actin filaments are dynamically reorganized to accommodate ever-changing cellular needs for intracellular transport, morphogenesis, and migration. Formins, a major family of actin nucleators, are believed to function as direct effectors of Rho GTPases, such as the polarity regulator Cdc42p. However, the presence of extensive redundancy has made it difficult to assess the in vivo significance of the low-affinity Rho GTPase–formin interaction and specifically whether Cdc42p polarizes the actin cytoskeleton via direct formin binding. Here we exploit a synthetically rewired budding yeast strain to eliminate the redundancy, making regulation of the formin Bni1p by Cdc42p essential for viability. Surprisingly, we find that direct Cdc42p–Bni1p interaction is dispensable for Bni1p regulation. Alternative paths linking Cdc42p and Bni1p via “polarisome” components Spa2p and Bud6p are also collectively dispensable. We identify a novel regulatory input to Bni1p acting through the Cdc42p effector, Gic2p. This pathway is sufficient to localize Bni1p to the sites of Cdc42p action and promotes a polarized actin organization in both rewired and wild-type contexts. We suggest that an indirect mechanism linking Rho GTPases and formins via Rho effectors may provide finer spatiotemporal control for the formin-nucleated actin cytoskeleton.     

The presence of serum creatine kinase 2 (MB) in hypokalemic familial periodic paralysis.

We recently found 17 U/l of isoenzyme creatine kinase (CK) 2 (MB), or 3.2% of total 533 U/l CK activity, in a patient with hypokalemic familial periodic paralysis who did not show clinical or EKG evidence of acute myocardial necrosis. The myopathy associated with hypokalemic familial periodic paralysis is thus another cause for the presence of CK 2 (MB). CK 2 (MB) is not a specific isoenzyme for myocardial damage since it may be identified in the serum of patients with skeletal muscle conditions.