Global Journalist: Reporters on the Iraq War

This Global Journalist show from April 3, 2003 features several journalists discussing how they view the recent progress of the American and British forces in the Iraq war. Jennifer Hamarneh, at the time the editor-in-chief of The Jordan Times, talks about hearing from Matthew McAllester, a reporter who was held captive in Iraq for over a week. Host: Stuart Loory. Guests: Jennifer Hamarneh (Jordan), Reinhard Meier (Switzerland), Edward Lucas (London), Dan Sneider (California). Producers: Sara Andrea Fajardo, Augustine Pang. Director: Pat Akers

Snake prices and crocodile appetites: Aquatic wildlife supply and demand on Tonle Sap Lake, Cambodia

Commercial trade is a major driver of over-exploitation of wild species, but the pattern of demand and how it responds to changes in supply is poorly understood. Here we explore the markets for snakes from Tonle Sap Lake in Cambodia to evaluate future exploitation scenarios, identify entry points for conservation and, more generally, to illustrate the value of multi-scale analysis of markets to traded wildlife conservation. In Cambodia, the largest driver of snake exploitation is the domestic trade in snakes as crocodile food. We estimate that farmed crocodiles consume between 2.7 and 12.2 million snakes per year. The market price for crocodiles has been in decline since 2003, which, combined with rising prices for their food, has led to a reduced frequency of feeding and closure of small farms. The large farms that generate a disproportionate amount of the demand for snakes continue to operate in anticipation of future market opportunities, and preferences for snakes could help maintain demand if market prices for crocodiles rise to pre 2003 levels. In the absence of a sustained demand from crocodile farms, it is also possible that alternative markets will develop, such as one for human snack food. The demand for snakes, however, also depends on the availability of substitute resources, principally fish. The substitutability and low price elasticity of demand offers a relatively sustainable form of consumerism. Given the nature of these market drivers, addressing consumer preferences and limiting the protection of snakes to their breeding season are likely to be the most effective tools for conservation. This study highlights the importance of understanding the structure of markets and the behaviour of consumer demand prior to implementing regulations on wildlife hunting and trade

Molecular basis of fatty acid selectivity in the zDHHC family of S-acyltransferases revealed by click chemistry

S-Acylation is a major post-translational modification, catalysed by the zDHHC enzyme family. S-acylated proteins can be modified by different fatty acids; however, very little is known about how zDHHC enzymes contribute to acyl chain heterogeneity. Here, we employed fatty acid azide/alkyne labelling of mammalian cells, showing their transformation into acyl-CoAs and subsequent click chemistry-based detection, to demonstrate that zDHHC enzymes have marked differences in their fatty acid selectivity. This was apparent even for highly related enzymes such as zDHHC3 and zDHHC7, which displayed a marked difference in ability to use C18:0 acyl CoA as a substrate. Furthermore, we identified Isoleucine-182 in the third transmembrane domain of zDHHC3 as a key determinant limiting the use of longer chain acyl-CoAs by this enzyme. This is the first study to uncover differences in the fatty acid selectivity profiles of cellular zDHHC enzymes and to map molecular determinants governing this selectivit

Accelerating the monitoring of global biodiversity : Revisiting the sampled approach to generating Red List Indices

Abstract Given the current biodiversity crisis, pragmatic approaches to detect global conservation trends across a broad range of taxa are critical. A sampled approach to the Red List Index (RLI) was proposed, as many groups are highly speciose. However, a decade after its conception, the recommended 900 species sample has only been implemented in six groups and trend data are available for none, potentially because this sample is unfeasibly high. Using a broader set of all available data we show that when re-assessments are conducted every 10 years, 200 species (400 in some cases) should be sufficient to detect a RLI trend. Correctly detecting changes in slope still requires samples of 900 species (11,000 in some cases). Sampled assessments can accelerate biodiversity monitoring and complement current metrics, but the time-period between assessments and the approaches? purpose should be carefully considered, as there is a trade-off between sample size and the resulting indices.Peer reviewe

Bcl11a Deficiency Leads to Hematopoietic Stem Cell Defects with an Aging-like Phenotype

SummaryB cell CLL/lymphoma 11A (BCL11A) is a transcription factor and regulator of hemoglobin switching that has emerged as a promising therapeutic target for sickle cell disease and thalassemia. In the hematopoietic system, BCL11A is required for B lymphopoiesis, yet its role in other hematopoietic cells, especially hematopoietic stem cells (HSCs) remains elusive. The extensive expression of BCL11A in hematopoiesis implicates context-dependent roles, highlighting the importance of fully characterizing its function as part of ongoing efforts for stem cell therapy and regenerative medicine. Here, we demonstrate that BCL11A is indispensable for normal HSC function. Bcl11a deficiency results in HSC defects, typically observed in the aging hematopoietic system. We find that downregulation of cyclin-dependent kinase 6 (Cdk6), and the ensuing cell-cycle delay, correlate with HSC dysfunction. Our studies define a mechanism for BCL11A in regulation of HSC function and have important implications for the design of therapeutic approaches to targeting BCL11A

A high cholecystectomy rate in a cohort of Mexican American women who are postpartum at the time of oral contraceptive pill initiation

Opinions differ regarding the association between gallbladder disease and oral contraceptive (OCs). The objective of this paper is to quantify cholecystectomy rate among women initiating OCs

The PCP genes Celsr1 and Vangl2 are required for normal lung branching morphogenesis

The lungs are generated by branching morphogenesis as a result of reciprocal signalling interactions between the epithelium and mesenchyme during development. Mutations that disrupt formation of either the correct number or shape of epithelial branches affect lung function. This, in turn, can lead to congenital abnormalities such as cystadenomatoid malformations, pulmonary hypertension or lung hypoplasia. Defects in lung architecture are also associated with adult lung disease, particularly in cases of idiopathic lung fibrosis. Identifying the signalling pathways which drive epithelial tube formation will likely shed light on both congenital and adult lung disease. Here we show that mutations in the planar cell polarity (PCP) genes Celsr1 and Vangl2 lead to disrupted lung development and defects in lung architecture. Lungs from Celsr1Crsh and Vangl2Lp mouse mutants are small and misshapen with fewer branches, and by late gestation exhibit thickened interstitial mesenchyme and defective saccular formation. We observe a recapitulation of these branching defects following inhibition of Rho kinase, an important downstream effector of the PCP signalling pathway. Moreover, epithelial integrity is disrupted, cytoskeletal remodelling perturbed and mutant endoderm does not branch normally in response to the chemoattractant FGF10. We further show that Celsr1 and Vangl2 proteins are present in restricted spatial domains within lung epithelium. Our data show that the PCP genes Celsr1 and Vangl2 are required for foetal lung development thereby revealing a novel signalling pathway critical for this process that will enhance our understanding of congenital and adult lung diseases and may in future lead to novel therapeutic strategies

Factors affecting ammonium uptake in streams - an inter-biome perspective

The Lotic Intersite Nitrogen experiment (LINX) was a coordinated study of the relationships between North American biomes and factors governing ammonium uptake in streams. Our objective was to relate inter-biome variability of ammonium uptake to physical, chemical and biological processes. 2. Data were collected from 11 streams ranging from arctic to tropical and from desert to rainforest. Measurements at each site included physical, hydraulic and chemical characteristics, biological parameters, whole-stream metabolism and ammonium uptake. Ammonium uptake was measured by injection of \u275~-ammonium and downstream measurements of 15N-ammonium concentration. 3. We found no general, statistically significant relationships that explained the variability in ammonium uptake among sites. However, this approach does not account for the multiple mechanisms of ammonium uptake in streams. When we estimated biological demand for inorganic nitrogen based on our measurements of in-stream metabolism, we found good correspondence between calculated nitrogen demand and measured assimilative nitrogen uptake. 4. Nitrogen uptake varied little among sites, reflecting metabolic compensation in streams in a variety of distinctly different biomes (autotrophic production is high where allochthonous inputs are relatively low and vice versa). 5. Both autotrophic and heterotrophic metabolism require nitrogen and these biotic processes dominate inorganic nitrogen retention in streams. Factors that affect the relative balance of autotrophic and heterotrophic metabolism indirectly control inorganic nitrogen uptake