1,548 research outputs found
The legend of Achaneh: Socio-ecological knowledge in the oral tradition of fisherwomen in Veracruz, Mexico
Based on ethnographic fieldwork conducted in an indigenous community of Veracruz, Mexico, traditional socio-ecological knowledge was identified embedded in the oral tradition of fisherwomen of the local community. The reflections presented show the educational potential of indigenous knowledge that, from their own epistemology, has allowed the inhabitants of this community to regulate the way in which they relate to each other and to their environment in a sustainable way over the centuries. The findings presented in this article bear testimony to the socio-environmental relevance of these local indigenous narratives as situated philosophies which are important to document so as to move towards a scenario of sustainability arising from a dialogue between the local and the global
Design, expression, and characterization of an asymmetric bispecific antibody fused to a scFv shuttle for brain uptake
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Differential regulation of somatostatin receptors 1 and 2 mRNA and protein expression by tamoxifen and estradiol in breast cancer cells
Somatostatin (SST) inhibition of hormone hypersecretion from tumors is mediated by somatostatin receptors (SSTRs). SSTRs also play an important role in controlling tumor growth through specific antiproliferative actions. These receptors are well expressed in numerous normal and tumor tissues and are susceptible to regulation by a variety of factors. Estradiol, a potent trophic and mitogenic hormone in its target tissues, is known to modulate the expression of SST and its receptors. Accordingly, in the present study, we determined the effects of tamoxifen, a selective estrogen receptor (ER) modulator (SERM), and estradiol on SSTR1 and SSTR2 expression at the mRNA and protein levels in ER-positive and -negative breast cancer cells. We found that SSTR1 was upregulated by tamoxifen in a dose-dependent manner but no effect was seen with estradiol. In contrast, SSTR2 was upregulated by both tamoxifen and estradiol. Combined treatment caused suppression of SSTR1 below control levels but had no significant effect on SSTR2. Treatment with SSTR1-specific agonist was significantly more effective in suppressing cell proliferation of cells pre-treated with tamoxifen. Taking these data into consideration, we suggest that tamoxifen and estradiol exert variable effects on SSTR1 and SSTR2 mRNA and protein expression and distributional pattern of the receptors. These changes are cell subtype-specific and affect the ability of SSTR agonists to inhibit cell proliferation
Fruit cell culture as a model system to study cell wall changes during strawberry fruit ripening
Strawberry (Fragaria x ananassa, Duch.) fruit is characterized by its fast ripening and soft texture at the ripen stage, resulting in a short postharvest shelf life and high economic losses. It is generally believed that the disassembly of cell walls, the dissolution of the middle lamella and the reduction of cell turgor are the main factors determining the softening of fleshy fruits. In strawberry, several studies indicate that the solubilisation and depolymerisation of pectins, as well as the depolymerisation of xyloglucans, are the main processes occurring during ripening. Functional analyses of genes encoding pectinases such as polygalacturonase and pectate lyase also point out to the pectin fraction as a key factor involved in textural changes. All these studies have been performed with whole fruits, a complex organ containing different tissues that differ in their cell wall composition and undergo ripening at different rates. Cell cultures derived from fruits have been proposed as model systems for the study of several processes occurring during fruit ripening, such as the production of anthocyanin and its regulation by plant hormones. The main objective of this research was to obtain and characterize strawberry cell cultures to evaluate their potential use as a model for the study of the cell wall disassembly process associate with fruit ripening. Cell cultures were obtained from cortical tissue of strawberry fruits, cv. Chandler, at the stages of unripe-green, white and mature-red. Additionally, a cell culture line derived from strawberry leaves was obtained. All cultures were maintained in solid medium supplemented with 2.5 mg.l-1 2,4-D and incubated in the dark. Cell walls from the different callus lines were extracted and fractionated to obtain CDTA and sodium carbonate soluble pectin fractions, which represent polyuronides located in the middle lamella or the primary cell wall, respectively. The amounts of homogalacturonan in both fractions were estimated by ELISA using LM19 and LM20 antibodies, specific against demethylated and methyl-esterified homogalacturonan, respectively. In the CDTA fraction, the cell line from ripe fruit showed a significant lower amount of demethylated pectins than the rest of lines. By contrast, the content of methylated pectins was similar in green- and red-fruit lines, and lower than in white-fruit and leaf lines. In the sodium carbonate pectin fraction, the line from red fruit also showed the lowest amount of pectins. These preliminary results indicate that cell cultures obtained from fruits at different developmental stages differ in their cell wall composition and these differences resemble to some extent the changes that occur during strawberry softening. Experiments are in progress to further characterize cell wall extracts with monoclonal antibodies against other cell wall epitopes.Universidad de Málaga. Campus de Excelencia Internacional AndalucĂa Tech
On the heterochromatic number of hypergraphs associated to geometric graphs and to matroids
The heterochromatic number hc(H) of a non-empty hypergraph H is the smallest
integer k such that for every colouring of the vertices of H with exactly k
colours, there is a hyperedge of H all of whose vertices have different
colours. We denote by nu(H) the number of vertices of H and by tau(H) the size
of the smallest set containing at least two vertices of each hyperedge of H.
For a complete geometric graph G with n > 2 vertices let H = H(G) be the
hypergraph whose vertices are the edges of G and whose hyperedges are the edge
sets of plane spanning trees of G. We prove that if G has at most one interior
vertex, then hc(H) = nu(H) - tau(H) + 2. We also show that hc(H) = nu(H) -
tau(H) + 2 whenever H is a hypergraph with vertex set and hyperedge set given
by the ground set and the bases of a matroid, respectively
Las sociedades cientĂficas de estudiantes de odontologĂa: una fuerza motriz para la investigaciĂłn.
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Flow-Path: An AllPath flow-based protocol
The work at: The 37th IEEE Conference on Local Computer Networks (LCN). Clearwater, Florida, USA. Date: 22-25 October 2012This paper describes Flow-Path, an AllPath flowbased switching protocol that features improved load adaptive properties. Upon arrival of a new flow to the network, it explores every possible path reaching from source to destination host and selects the lowest latency path at the moment. It is based on the same basic principle than ARPPath, that is, snooping the ARP protocol dialog (request and reply messages) to explore all available paths at the same time that address resolution takes place, but it is flow-based instead of source address-based. While preserving the main advantages of ARP-Path: shortest path bridging exploiting the full network topology, Flow-Path has the advantages of full independence of flows at the time of path creation and guarantees path symmetry (congruency) and increased path diversity. Flow-Path thus improves load distribution, at the expense of increased address table size in each bridge.This work was supported in part by grants from
Comunidad de Madrid and Comunidad de Castilla-La
Mancha through Projects MEDIANET-CM (S-2009/TIC-
1468) and EMARECE (PII1I09-0204-4319).Publicad
Landscape, memory and learning to change in changing worlds:Contemplating intergenerational learning and traditional knowledge practices within social-ecological landscapes of change
The core paper and collection of short papers from Mexico, Africa, India and Sweden that make up this study on social-ecological landscapes developed as a South–South collaboration that was extended to include a case in the North. Our concern was to explore how situated, intergenerational knowledge commonly takes a back seat to the conceptual propositions that the environmental sciences have developed around matters of concern like biodiversity loss. In this way, scientific propositions have become the conceptual capital for informing future sustainability through Education for Sustainable Development (ESD). In response to this, a more situated turn has developed to engage both intergenerational practices and the institutional sciences, but the playing fields are seldom level and deliberations are often rife with misunderstandings.Current trajectories of social-ecological change were already evident at the turn of the 20th century where one found the colonial oppression of indigenous peoples and early manifestations of accelerating environmental degradation. The latter escalated into biodiversity loss as a global concern that both underpins and resonates with the current complex of global risks. This concern has shaped education imperatives towards learning-led change so as to contribute to avoiding catastrophic problems such as climate change and ocean acidification, for example. These and other critical sustainability concerns have developed as planetary limits are being exceeded on a widening scale. The associated patterns of change and escalating risk in the modern era have played out in each of the regions where our teams of authors have researched their short papers on social-ecological change and intergenerational learning. The papers are intended as contributions that might better situate indigenous peoples on their intergenerational lands in reflexive learning within a rich mix of ancient and modern scientific ideas and ideals
Culture-Negative Endocarditis Complicated with Mycotic Aneurysm and Intracranial Bleed - A Case Report
Background: Blood culture-negative infective endocarditis (IE) requires at least three independent blood samples with negative cultures after seven days of incubation. Ischemic events are the most frequent neurologic complication of IE with intracranial mycotic aneurysms being the consequence of displacement of septic emboli from valvular vegetations. In this case report, we describe a young gentleman who initially presented with neurologic deficit and was later found to have mycotic aneurysms and culture negative infective endocarditis.
Case Presentation: A 34-year-old man with a past medical history of Tourette Syndrome presented to the Emergency department (ED) due to acute change in mental status. In the ED, the patient was found to have a Glasgow Coma Scale of 4 and was immediately intubated. Initial computed tomography (CT) of the head without contrast showed a large intraparenchymal hematoma within the left frontal lobe with internal hypoechoic densities suggesting active bleeding and a left-to-right midline shift. A subarachnoid hemorrhage was also noted on the left. The patient was taken to the operating room for emergent right ventriculostomy placement. Subsequent CT angiography of the head revealed a focal lobulated area of contrast density suspicious for a ruptured aneurysm. An additional peripheral aneurysm was found within the peripheral aspect of the right parietal lobe. Due to peripheral location of the aneurysms, they were deemed to be mycotic and patient underwent embolization of the left frontal and right parietal aneurysms. Patient was initially treated with vancomycin and piperacillin-tazobactam for the first 24 hours and was later switched to vancomycin, ceftriaxone, and tobramycin by the infectious disease specialist. Due to patient having recurrent fevers despite antibiotic therapy, a transesophageal echocardiogram (TEE) was performed showing a small mobile echodensity on the anterior leaflet of the mitral valve, highly suspicious of vegetation and endocarditis. The anaerobic bottle of the initial blood culture grew anaerobic gram-positive cocci, identified as Finegoldia magna suspected to be a contaminant. Subsequent cultures were negative.
Conclusion: Currently, there are no randomized trials to guide the management of infected aneurysms. Management strategies are based upon clinical experience usually with antibiotic therapy combined with surgical debridement and revascularization
ARP-Path: ARP-based Shortest Path Bridges
This letter is a summary proposal for an evolution of the Ethernet transparent bridge paradigm that provides simple, shortest path bridging in campus networks. ARP-Path Ethernet Switches set up an on-demand path between two hosts just reusing and flooding the standard ARP request frame through all links and confirming the path reaching to the destination host with the ARP reply frame. ARP-Path uses the standard Ethernet frame format, is fully transparent to hosts and does not require spanning tree or link state protocol. Simulation results show superior performance to spanning tree and similar to shortest path routing, with lower complexity. Our implementations confirm backward compatibility, robustness and performance.This work was supported in part by grants from Comunidad de Madrid
and Comunidad de Castilla la Mancha through Projects MEDIANET-CM (S-
2009/TIC-1468) and EMARECE (PII1I09-0204-4319).Publicad
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