Witten's conjecture and Property P

Let K be a non-trivial knot in the 3-sphere and let Y be the 3-manifold obtained by surgery on K with surgery-coefficient 1. Using tools from gauge theory and symplectic topology, it is shown that the fundamental group of Y admits a non-trivial homomorphism to the group SO(3). In particular, Y cannot be a homotopy-sphere.Comment: Published by Geometry and Topology at http://www.maths.warwick.ac.uk/gt/GTVol8/paper7.abs.html Version 5: links correcte

The Routine Use of Antibiotics to Promote Animal Growth Does Little to Benefit Protein Undernutrition in the Developing World

Some persons argue that the routine addition of antibiotics to animal feed will help alleviate protein undernutrition in developing countries by increasing meat production. In contrast, we estimate that, if all routine antibiotic use in animal feed were ceased, there would be negligible effects in these countries. Poultry and pork production are unlikely to decrease by more than 2%. Average daily protein supply would decrease by no more than 0.1 g per person (or 0.2% of total protein intake). Eliminating the routine use of in-feed antibiotics will improve human and animal health, by reducing the development and spread of antibiotic-resistant bacteri

Cardiorenal syndrome type 3: pathophysiologic and epidemiologic considerations

Cardiorenal syndrome (CRS) type 3 is a subclassification of the CRS whereby an episode of acute kidney injury (AKI) precipitates and contributes to the development of acute cardiac injury. There is limited understanding of the pathophysiologic mechanisms of how AKI contributes to acute cardiac injury and/or dysfunction. An episode of AKI may have effects that depend on the severity and duration of AKI and that both directly and indirectly predispose to an acute cardiac event. Moreover, baseline susceptibility will modify the subsequent risk for cardiac events associated with AKI. Experimental data suggest cardiac injury may be directly induced by inflammatory mediators, oxidative stress, apoptosis and activation of neuroendocrine systems early after AKI. Likewise, AKI may be associated with physiologic derangements (i.e. volume overload; metabolic acidosis, retention of uremic toxins, hyperkalemia; hypocalcemia), alterations to coronary vasoreactivity, and ventricular remodeling and fibrosis that indirectly exert negative effects on cardiac function. AKI may also adversely impact cardiac function by contributing to alternations in drug pharmacokinetics and pharmacodynamics. Additional experimental and translational investigations coupled with epidemiologic surveys are needed to better explore that pathophysiologic mechanisms underpinning acute cardiac events associated with AKI and their impact on outcomes

The Acacia controversy resulting from minority rule at the Vienna Nomenclature Section : much more than arcane arguments and complex technicalities

The arguments towards resolving the Acacia nomenclatural controversy put forth by Thiele & al. (2011) are reviewed and rebutted. We argue that a truly pragmatic and, moreover, defensible and equitable alternative to accepting the retypification of Acacia Mill. with a conserved type would be to have the 2006 International Code of Botanical Nomenclature, excluding this retypification, serve as the basis for discussions at the Nomenclature Section of the Melbourne International Botanical Congress in 2011. We, and a large component of the international taxonomic community, and beyond, remain convinced that the minority rule voting procedure used at Vienna on Acacia was inappropriate, resulting in animosity that will without any doubt linger until this situation is rectified. Such a minority rule procedure has never in the history of Nomenclature Sections been implemented before. Exclusion of the Acacia retypification can be achieved through a democratic process by objecting to its inclusion when the printed (2006) Code comes up for adoption at the start of the Nomenclature Section. This is perfectly within the established process that has been used in past Section meetings. The integrity of the Code will suffer permanent damage if the retypification of Acacia Mill. with a conserved type is not removed from the ICBN, especially as it ended up there through a minority decision.http://www.botanik.univie.ac.at/iapt/s_taxon.ph

Enhancement of Polymeric Immunoglobulin Receptor Transcytosis by Biparatopic VHH

The polymeric immunoglobulin receptor (pIgR) ensures the transport of dimeric immunoglobulin A (dIgA) and pentameric immunoglobulin M (pIgM) across epithelia to the mucosal layer of for example the intestines and the lungs via transcytosis. Per day the human pIgR mediates the excretion of 2 to 5 grams of dIgA into the mucosa of luminal organs. This system could prove useful for therapies aiming at excretion of compounds into the mucosa. Here we investigated the use of the variable domain of camelid derived heavy chain only antibodies, also known as VHHs or Nanobodies®, targeting the human pIgR, as a transport system across epithelial cells. We show that VHHs directed against the human pIgR are able to bind the receptor with high affinity (∼1 nM) and that they compete with the natural ligand, dIgA. In a transcytosis assay both native and phage-bound VHH were only able to get across polarized MDCK cells that express the human pIgR gene in a basolateral to apical fashion. Indicating that the VHHs are able to translocate across epithelia and to take along large particles of cargo. Furthermore, by making multivalent VHHs we were able to enhance the transport of the compounds both in a MDCK-hpIgR and Caco-2 cell system, probably by inducing receptor clustering. These results show that VHHs can be used as a carrier system to exploit the human pIgR transcytotic system and that multivalent compounds are able to significantly enhance the transport across epithelial monolayers

Unlocking the grid: Language-in-education policy realisation in post-apartheid South Africa

This paper reflects on the state of educational language policy two decades into a postApartheid South Africa caught between official multilingualism and English. The focus is on the national language-in-education policy (LiEP) that advocates additive bi/multilingualism, and a provincial counterpart, the language transformation plan (LTP). Using Ricento and Hornberger’s onion metaphor, the paper seeks to uncover the meanings of policy realisation in education at legislative, institutional, and interpersonal levels. The LiEP’s non-realisation at institutional level is indexed by a ‘gridlock of collusion’ (Alexander, personal communication) between political elites and the majority of African-language speakers, who emulatively seek the goods that an English-medium education promises. To illustrate how teachers can become policy advocates, data are presented from a bilingual education in-service programme that supported the LTP. The paper argues that sociolinguistic insights into speakers’ heteroglossic practices should be used to counter prevailing monoglossic policy discourses and school language practices, and that all languages should be used as learning resources. Strategic essentialism would recognise the schooling system’s need to separately classify language subjects and to identify the languages most productively used for teaching across the curriculum. The paper concludes with a call for the revision of the LiEP