Latin American Economic Integration: An Overview of Trade and Investment Developments in ANCOM, CACM, and LAFTA

This article examines different approaches towards greater economic cooperation among Latin American countries that have been taken

Sea urchin embryo cell aggregation with UDP and UDP-sugars

Cell surface characteristics and properties are important due to their involvement in embryogenesis, oncogenesis and metastasis. Sugar chains reaching away from the cell surface are the first line of contact between two approaching cells. Glycosyltransferases are enzymes that will act on sugar substrates adding a specific sugar to the sugar chain on the cell membrane. This study was done to further explore the glycosyltransferase model of cell adhesion developed by Roseman which proposes that cell-cell adhesion is mediated by glycosyltransferases on one cell binding to sugar-containing receptors on the other. UDP, UDP-sugars or free sugars were added to 23 hour sea urchin embryo cells, and rotated at 15� C for one hour. After this period, numbers of single cells, doubles, triplets and clusters of cells were determined for each sample. The study was performed using two species of sea urchin: Strongylocentrotus purpuratus and Lytechinus pictus. Results were similar for both species. UDP and UDP-sugars showed markedly effected cell reaggregation. UDP promoted reaggregation most strongly, followed by UDP-glucose, UDP-N-acetylglucosamine, and UDP-galactose. Free galactose was also tested, and it had little effect on cell reaggregation. Alpha lactalbumin, a glycosyltransferase inhibitor, inhibited reaggregation in all samples, except in the galactose sample. The results suggest that UDP and UDP-sugars may enhance cell reaggregation by charge effects or by enhancing surface glycosyltransferases, or through metabolic utilization. Inhibition of the observed effects by a-lactalbumin suggests that glycosyltransferases may be involved in sea urchin embryo cell adhesion.Includes bibliographical references (leaves 29-32)California State University, Northridge. Department of Biology

Simplified mathematical model of proton exchange membrane fuel cell based on horizon fuel cell stack

This paper presents a simplified zero-dimensional mathematical model for a self-humidifying proton exchange membrane (PEM) fuel cell stack of 1 kW. The model incorporates major electric and thermodynamic variables and parameters involved in the operation of the PEM fuel cell under different operational conditions. Influence of each of these parameters and variables upon the operation and the performance of the PEM fuel cell are investigated. The mathematical equations are modeled by using Matlab–Simulink tools in order to simulate the operation of the developed model with a commercial available 1 kW horizon PEM fuel cell stack (H-1000), which is used for the purposes of model validation and tuning of the developed model. The model can be extrapolated to higher wattage fuel cells of similar arrangements. New equation is presented to determine the impact of using air to supply the PEM fuel cell instead of pure oxygen upon the concentration losses and the output voltage when useful current is drawn from it

Improved functionalization of oleic acid-coated iron oxide nanoparticles for biomedical applications

Superparamagnetic iron oxide nanoparticles can providemultiple benefits for biomedical applications in aqueous environments such asmagnetic separation or magnetic resonance imaging. To increase the colloidal stability and allow subsequent reactions, the introduction of hydrophilic functional groups onto the particles’ surface is essential. During this process, the original coating is exchanged by preferably covalently bonded ligands such as trialkoxysilanes. The duration of the silane exchange reaction, which commonly takes more than 24 h, is an important drawback for this approach. In this paper, we present a novel method, which introduces ultrasonication as an energy source to dramatically accelerate this process, resulting in high-quality waterdispersible nanoparticles around 10 nmin size. To prove the generic character, different functional groups were introduced on the surface including polyethylene glycol chains, carboxylic acid, amine, and thiol groups. Their colloidal stability in various aqueous buffer solutions as well as human plasma and serum was investigated to allow implementation in biomedical and sensing applications.status: publishe

Pleural inflammatory myofibroblastoma: a locally aggressive intra-thoracic tumour

A 41-year old non-smoking woman presented with persistent pleural effusion. Pleural fluid was hemorrhagic and fluid cytology was negative for malignant cells. A working diagnosis of chronic haemothorax was made and standard right thoracotomy was performed to identify the source of bleeding. A 10 × 10 cms poorly circumscribed mass containing blood clots, altered blood, fibrous tissue, and gelatinous debris was found and demonstrated features of inflammatory myofibroblastoma on immunohistochemistry. Thirteen months later, the patient developed a local recurrence, which was treated surgically. Semi-solid physical appearance of this tumour has not been reported previously. This case report further adds to the diagnostic dilemma related with this tumour

Laminin database: a tool to retrieve high-throughput and curated data for studies on laminins

The Laminin(LM)-database, hosted at http://www.lm.lncc.br, is the first database focusing a non-collagenous extracellular matrix protein family, the LMs. Part of the knowledge available in this website is automatically retrieved, whereas a significant amount of information is curated and annotated, thus placing LM-database beyond a simple repository of data. In its home page, an overview of the rationale for the database is seen and readers can access a tutorial to facilitate navigation in the website, which in turn is presented with tabs subdivided into LMs, receptors, extracellular binding and other related proteins. Each tab opens into a given LM or LM-related molecule, where the reader finds a series of further tabs for ‘protein’, ‘gene structure’, ‘gene expression’ and ‘tissue distribution’ and ‘therapy’. Data are separated as a function of species, comprising Homo sapiens, Mus musculus and Rattus novergicus. Furthermore, there is specific tab displaying the LM nomenclatures. In another tab, a direct link to PubMed, which can be then consulted in a specific way, in terms of the biological functions of each molecule, knockout animals and genetic diseases, immune response and lymphomas/leukemias. LM-database will hopefully be a relevant tool for retrieving information concerning LMs in health and disease, particularly regarding the hemopoietic system

Surgery for recurrent inflammatory pseudotumor of the lung

<p>Abstract</p> <p>Background</p> <p>Cases of recurrent inflammatory pseudotumor have only rarely been reported. The treatment for recurrent pseudotumor is surgery. Patients not eligible for surgery require different treatment, and the optimal type of the treatment is controversial.</p> <p>Case Presentation</p> <p>A 54-year-old woman was noted to have an abnormal shadow in the right middle lung field on chest X-ray. Computed tomography of the chest revealed an infiltrative lesion in the right segment 4 and a nodule in the right segment 8. She underwent right middle lobectomy and partial resection of the right segment 8. Histopathology revealed non-atypical lymphocytes and plasma cells infiltrates, leading to the diagnosis of the lymphoplasmacytic type of inflammatory pseudotumor. During postoperative follow-up, chest computed tomography revealed a nodular lesion in the left segment 3 and an infiltrative lesion in the right segment 2. Left segment 3 segmentectomy and right segment 2 wedge resection were performed. The histopathological findings were similar to those of the first surgical specimen, leading to the diagnosis of recurrent lymphoplasmacytic type of inflammatory pseudotumor.</p> <p>Conclusion</p> <p>Surgical cases of recurrent inflammatory pseudotumor of the lung have been reported only very rarely. We believe that surgery is the best treatment for recurrent inflammatory pseudotumor of the lung when patients are eligible.</p

What Do Poor Women Want? Public Employment or Cash Transfers? Lessons from Argentina

The literature on public employment policies such as the job guarantee (JG) and the employer of last resort (ELR) often emphasizes their macroeconomic stabilization effects. But carefully designed and implemented policies like these can also have profound social transformative effects. In particular, they can help address enduring economic problems such as poverty and gender disparity. To examine how, this paper will look at the reform of Argentina’s Plan Jefes into Plan Familias. Plan Jefes was the hallmark stabilization policy of the Argentine government after the 2001 crisis. It guaranteed a public sector job in a community project to unemployed male and female heads of households. The vast majority of beneficiaries, however, turned out to be poor women. For a number of reasons that are explored below, the program was later reformed into a cash transfer policy, known as Plan Familias, that still exists today. The paper examines this reform in order to evaluate the relative impact of such policies on some of the most vulnerable members of society; namely, poor women. An examination of the Argentine experience based on survey evidence and fieldwork reveals that poor women overwhelmingly want paid work opportunities, and that a policy such as the JG or the ELR cannot only guarantees full employment and macroeconomic stabilization, but it can also serve as an institutional vehicle that begins to transform some of the structures and norms that produce and reproduce gender disparities. These transformative features of public employment policies are elucidated by turning to the capabilities approach developed by Amartya Sen and elaborated by Martha Nussbaum - an approach commonly invoked in the feminist literature. This paper examines how the access to paid employment can enhance what Sen defines as an individual’s 'substantive freedom'. Any policy that fosters genuine freedom begins with an understanding of what the targeted population (in this case, poor women) wants. It then devises a strategy that guarantees that such opportunities exist and removes the obstacles to accessing these opportunities

Evidence of Müller Glia Conversion Into Retina Ganglion Cells Using Neurogenin2

Degenerative retinopathies are the leading causes of irreversible visual impairment in the elderly, affecting hundreds of millions of patients. Müller glia cells (MGC), the main type of glia found in the vertebrate retina, can resume proliferation in the rodent adult injured retina but contribute weakly to tissue repair when compared to zebrafish retina. However, postnatal and adult mouse MGC can be genetically reprogrammed through the expression of the transcription factor (TF) Achaete-scute homolog 1 (ASCL1) into induced neurons (iNs), displaying key hallmarks of photoreceptors, bipolar and amacrine cells, which may contribute to regenerate the damaged retina. Here, we show that the TF neurogenin 2 (NEUROG2) is also sufficient to lineage-reprogram postnatal mouse MGC into iNs. The efficiency of MGC lineage conversion by NEUROG2 is similar to that observed after expression of ASCL1 and both TFs induce the generation of functionally active iNs. Treatment of MGC cultures with EGF and FGF2 prior to Neurog2 or Ascl1 expression enhances reprogramming efficiencies, what can be at least partially explained by an increase in the frequency of MGCs expressing sex determining region Y (SRY)-box 2 (SOX2). Transduction of either Neurog2 or Ascl1 led to the upregulation of key retina neuronal genes in MGC-derived iNs, but only NEUROG2 induced a consistent increase in the expression of putative retinal ganglion cell (RGC) genes. Moreover, in vivo electroporation of Neurog2 in late progenitors from the neonatal rat retina, which are transcriptionally similar to MGCs, also induced a shift in the generation of retinal cell subtypes, favoring neuronal differentiation at the expense of MGCs and resuming the generation of RGCs. Altogether, our data indicate that NEUROG2 induces lineage conversion of postnatal rodent MGCs into RGC-like iNs in vitro and resumes the generation of this neuronal type from late progenitors of the retina in vivo