162 research outputs found
A new approach to measure reduction intensity on cores and tools on cobbles: the Volumetric Reconstruction Method
Knowing to what extent lithic cores have been reduced through knapping is an important step toward understanding the technological variability of lithic assemblages and disentangling the formation processes of archaeological assemblages. In addition, it is a good complement to more developed studies of reduction intensity in retouched tools, and can provide information on raw material management or site occupation dynamics. This paper presents a new methodology for estimating the intensity of reduction in cores and tools on cobbles, the Volumetric Reconstruction Method (VRM). This method is based on a correction of the dimensions (length, width, and thickness) of each core from an assemblage. The mean values of thickness and platform thickness of the assemblage’s flakes are used as corrections for the cores’ original dimensions, after its diacritic analysis. Then, based on these new dimensions, the volume or mass of the original blank are reconstructed using the ellipsoid volume formula. The accuracy of this method was experimentally tested, reproducing a variety of possible archaeological scenarios. The experimental results demonstrate a high inferential potential of the VRM, both in estimating the original volume or mass of the original blanks, and in inferring the individual percentage of reduction for each core. The results of random resampling demonstrate the applicability of VRM to non size-biased archaeological contexts.Introduction Methods - The Volumetric Reconstruction Method - Experimental design - Statistical procedures - Resamples Results - Geometric formulas - Reduction strategy and size - Resampling (randomly biased record) - Resampling (size bias) - Measuring the effect of number of generations Discussion and conclusion
Optimal Distributed Fault-Tolerant Sensor Fusion: Fundamental Limits and Efficient Algorithms
Distributed estimation is a fundamental problem in signal processing which
finds applications in a variety of scenarios of interest including distributed
sensor networks, robotics, group decision problems, and monitoring and
surveillance applications. The problem considers a scenario where distributed
agents are given a set of measurements, and are tasked with estimating a target
variable. This work considers distributed estimation in the context of sensor
networks, where a subset of sensor measurements are faulty and the distributed
agents are agnostic to these faulty sensor measurements. The objective is to
minimize i) the mean square error in estimating the target variable at each
node (accuracy objective), and ii) the mean square distance between the
estimates at each pair of nodes (consensus objective). It is shown that there
is an inherent tradeoff between satisfying the former and latter objectives.
The tradeoff is explicitly characterized and the fundamental performance limits
are derived under specific statistical assumptions on the sensor output
statistics. Assuming a general stochastic model, the sensor fusion algorithm
optimizing this tradeoff is characterized through a computable optimization
problem. Finding the optimal sensor fusion algorithm is computationally
complex. To address this, a general class of low-complexity Brooks-Iyengar
Algorithms are introduced, and their performance, in terms of accuracy and
consensus objectives, is compared to that of optimal linear estimators through
case study simulations of various scenarios
Capacity Gains in MIMO Systems with Few-Bit ADCs Using Nonlinear Analog Operators
Analog to Digital Converters (ADCs) are a major contributor to the power
consumption of multiple-input multiple-output (MIMO) receivers with large
antenna arrays operating in the millimeter wave and terahertz carrier
frequencies. This is especially the case in large bandwidth terahertz
communication systems, due to the sudden drop in energy-efficiency of ADCs as
the sampling rate is increased above 100MHz. Two mitigating energy-efficient
approaches which have received significant recent interest are i) to reduce the
number of ADCs via analog and hybrid beamforming architectures, and ii) to
reduce the resolution of the ADCs which in turn decreases power consumption.
However, decreasing the number and resolution of ADCs leads to performance loss
-- in terms of achievable rates -- due to increased quantization error. In this
work, we study the application of practically implementable nonlinear analog
operators such as envelop detectors and polynomial operators, prior to sampling
and quantization at the ADCs, as a way to mitigate the aforementioned
rate-loss. A receiver architecture consisting of linear analog combiners,
nonlinear analog operators, and few-bit ADCs is designed. The fundamental
information theoretic performance limits of the resulting communication system,
in terms of achievable rates, are investigated under various assumptions on the
set of implementable analog operators. Various numerical evaluations and
simulations of the communication system are provided to compare the set of
achievable rates under different architecture designs and parameters. Circuit
simulations {in a 65 nm CMOS technology} exhibiting the generation of envelope
detectors and polynomial operators are provided, and their power consumption is
compared.Comment: arXiv admin note: substantial text overlap with arXiv:2208.0445
PAMAM dendrimers as a carbamazepine delivery system for neurodegenerative diseases: A biophysical and nanotoxicological characterization
Carbamazepine (CBZ) is an antiepileptic drug, which also could be used in the treatment of neurodegenerative diseases, such as the Alzheimer's disease. However, its use has been limited due to its low solubility, inefficient pharmacokinetic profiles, and multiple side effects. PAMAM dendrimers, ethylenediamine core, generation 4.0 (amine terminal groups) and 4.5 (carboxylate terminal groups) (DG4.0 and DG4.5 respectively) are polymers that can increase drug solubility through complexation. Thus, the aim of this work was to obtain and characterize complexes between CBZ and dendrimers. Both DG4.0 and DG4.5 allowed the incorporation of ∼20 molecules of CBZ per dendrimer, into their hydrophobic pockets. DG4.0-CBZ and DG4.5-CBZ complexes were found to be stable for 90 days at 37 °C and resistant to a lyophilization process, presenting controlled drug release. Also, the complexes nanotoxicity was tested ex vivo (human red blood cells), in vitro (N2a cell line), and in vivo (zebrafish). No hemolytic effect was observed in the ex vivo model. As regards in vitro toxicity, the DG4.5-CBZ complexes significantly reduced the toxicity caused by the free drug. Moreover, the DG4.5-CBZ did not cause neurotoxicity or cardiotoxicity in zebrafish larvae. In conclusion, a stable and biocompatible drug delivery system based on the DG4.5 capable of complex the CBZ has been developed. This achievement highlights the advantages of using negatively charged dendrimers for nanomedicine.Fil: Igartúa, Daniela. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Biomembranas; ArgentinaFil: Martinez, Carolina Soledad. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Biomembranas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Multidisciplinario de Biología Celular. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Multidisciplinario de Biología Celular. Universidad Nacional de La Plata. Instituto Multidisciplinario de Biología Celular; ArgentinaFil: Temprana, Carlos Facundo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Virologia; ArgentinaFil: Alonso, Silvia del Valle. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Biomembranas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Prieto, Maria Jimena. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Biomembranas; Argentin
PAMAM dendrimers as a carbamazepine delivery system for neurodegenerative diseases : A biophysical and nanotoxicological characterization
Carbamazepine (CBZ) is an antiepileptic drug, which also could be used in the treatment of neurodegenerative diseases, such as the Alzheimer's disease. However, its use has been limited due to its low solubility, inefficient pharmacokinetic profiles, and multiple side effects. PAMAM dendrimers, ethylenediamine core, generation 4.0 (amine terminal groups) and 4.5 (carboxylate terminal groups) (DG4.0 and DG4.5 respectively) are polymers that can increase drug solubility through complexation. Thus, the aim of this work was to obtain and characterize complexes between CBZ and dendrimers. Both DG4.0 and DG4.5 allowed the incorporation of ∼20 molecules of CBZ per dendrimer, into their hydrophobic pockets. DG4.0-CBZ and DG4.5-CBZ complexes were found to be stable for 90 days at 37 °C and resistant to a lyophilization process, presenting controlled drug release. Also, the complexes nanotoxicity was tested ex vivo (human red blood cells), in vitro (N2a cell line), and in vivo (zebrafish). No hemolytic effect was observed in the ex vivo model. As regards in vitro toxicity, the DG4.5-CBZ complexes significantly reduced the toxicity caused by the free drug. Moreover, the DG4.5-CBZ did not cause neurotoxicity or cardiotoxicity in zebrafish larvae. In conclusion, a stable and biocompatible drug delivery system based on the DG4.5 capable of complex the CBZ has been developed. This achievement highlights the advantages of using negatively charged dendrimers for nanomedicine.Instituto Multidisciplinario de Biología Celula
Oldowan Technology Amid Shifting Environments ∼2.03–1.83 Million Years Ago
The Oldowan represents the earliest recurrent evidence of human material culture and one of the longest-lasting forms of technology. Its appearance across the African continent amid the Plio-Pleistocene profound ecological transformations, and posterior dispersal throughout the Old World is at the foundation of hominin technological dependence. However, uncertainties exist concerning the degree to which the Oldowan constitutes an environment-driven behavioral adaptation. Moreover, it is necessary to understand how Oldowan technology varied through time in response to hominin ecological demands. In this study, we present the stone tool assemblage from Ewass Oldupa, a recently discovered archeological site that signals the earliest hominin occupation of Oldupai Gorge (formerly Olduvai) ∼2.03 Ma. At Ewass Oldupa, hominins underwent marked environmental shifts over the course of a ∼200 kyr period. In this article, we deployed an analysis that combines technological and typological descriptions with an innovative quantitative approach, the Volumetric Reconstruction Method. Our results indicate that hominins overcame major ecological challenges while relying on technological strategies that remained essentially unchanged. This highlights the Oldowan efficiency, as its basic set of technological traits was able to sustain hominins throughout multiple environments.Introduction Ewass Oldupa Materials and methods - Stone Tool Techno-Typological Analysis - The Volumetric Reconstruction Method Results - Assemblage Overview - Techno-Typological Variation Over Time and Across Environments - The Volumetric Reconstruction Method Discussio
PAMAM dendrimers as a carbamazepine delivery system for neurodegenerative diseases : A biophysical and nanotoxicological characterization
Carbamazepine (CBZ) is an antiepileptic drug, which also could be used in the treatment of neurodegenerative diseases, such as the Alzheimer's disease. However, its use has been limited due to its low solubility, inefficient pharmacokinetic profiles, and multiple side effects. PAMAM dendrimers, ethylenediamine core, generation 4.0 (amine terminal groups) and 4.5 (carboxylate terminal groups) (DG4.0 and DG4.5 respectively) are polymers that can increase drug solubility through complexation. Thus, the aim of this work was to obtain and characterize complexes between CBZ and dendrimers. Both DG4.0 and DG4.5 allowed the incorporation of ∼20 molecules of CBZ per dendrimer, into their hydrophobic pockets. DG4.0-CBZ and DG4.5-CBZ complexes were found to be stable for 90 days at 37 °C and resistant to a lyophilization process, presenting controlled drug release. Also, the complexes nanotoxicity was tested ex vivo (human red blood cells), in vitro (N2a cell line), and in vivo (zebrafish). No hemolytic effect was observed in the ex vivo model. As regards in vitro toxicity, the DG4.5-CBZ complexes significantly reduced the toxicity caused by the free drug. Moreover, the DG4.5-CBZ did not cause neurotoxicity or cardiotoxicity in zebrafish larvae. In conclusion, a stable and biocompatible drug delivery system based on the DG4.5 capable of complex the CBZ has been developed. This achievement highlights the advantages of using negatively charged dendrimers for nanomedicine.Instituto Multidisciplinario de Biología Celula
Enhanced gold nanoparticle-tumor cell recognition by albumin multilayer coating
Background: In a biological environment, nanoparticles are rapidly coated with serum proteins, which affects the NPs transport through biological medium, cellular uptake and response, all of which can impair therapeutic efficiency. Reduction of non-specific adsorption of proteins is mandatory to overcome this drawback.
Aim: We propose to use albumin to prepare a multilayer coating of NPs to reduce the non-specific protein interactions in biological media.
Materials & methods: Biohybrid NPs (bioHNPs) prepared by coating gold NPs with a multilayer of albumin and finally decorated with Bombesin-related peptides (BD-bioHNPs).
Results: BioHNPs/biological media interaction was characterized by physicochemical and biological techniques under near-physiological conditions. A significant reduction of the Corona effect and enhanced in vitro uptake to PC-3 cells was demonstrated for BD-bioHNPs.
Conclusion: This methodology to prepare decorated bioHNPs allows the preparation of ‘stealth’ NPs with improved cell targeting and the ability to avoid non-specific interactions with the biological media.Fil: Achilli, Estefanía Edith. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Multidisciplinario de Biología Celular. Grupo Vinculado al IMBICE - Grupo de Biología Estructural y Biotecnología - Universidad Nacional de Quilmes - GBEyB | Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Multidisciplinario de Biología Celular. Grupo Vinculado al IMBICE - Grupo de Biología Estructural y Biotecnología - Universidad Nacional de Quilmes - GBEyB | Universidad Nacional de La Plata. Instituto Multidisciplinario de Biología Celular. Grupo Vinculado al IMBICE - Grupo de Biología Estructural y Biotecnología - Universidad Nacional de Quilmes - GBEyB; Argentina. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología; ArgentinaFil: Flores, Constanza Yanel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Multidisciplinario de Biología Celular. Grupo Vinculado al IMBICE - Grupo de Biología Estructural y Biotecnología - Universidad Nacional de Quilmes - GBEyB | Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Multidisciplinario de Biología Celular. Grupo Vinculado al IMBICE - Grupo de Biología Estructural y Biotecnología - Universidad Nacional de Quilmes - GBEyB | Universidad Nacional de La Plata. Instituto Multidisciplinario de Biología Celular. Grupo Vinculado al IMBICE - Grupo de Biología Estructural y Biotecnología - Universidad Nacional de Quilmes - GBEyB; Argentina. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología; Argentina. Universidad Nacional Arturo Jauretche; ArgentinaFil: Temprana, Carlos Facundo. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Virología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario; ArgentinaFil: Alonso, Silvia del Valle. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Multidisciplinario de Biología Celular. Grupo Vinculado al IMBICE - Grupo de Biología Estructural y Biotecnología - Universidad Nacional de Quilmes - GBEyB | Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Multidisciplinario de Biología Celular. Grupo Vinculado al IMBICE - Grupo de Biología Estructural y Biotecnología - Universidad Nacional de Quilmes - GBEyB | Universidad Nacional de La Plata. Instituto Multidisciplinario de Biología Celular. Grupo Vinculado al IMBICE - Grupo de Biología Estructural y Biotecnología - Universidad Nacional de Quilmes - GBEyB; ArgentinaFil: Radrizzani Helguera, Martin. Universidad Nacional de San Martín. Escuela de Ciencia y Tecnología. Laboratorio de Neuroingeniería; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario; ArgentinaFil: Grasselli, Mariano. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Multidisciplinario de Biología Celular. Grupo Vinculado al IMBICE - Grupo de Biología Estructural y Biotecnología - Universidad Nacional de Quilmes - GBEyB | Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Multidisciplinario de Biología Celular. Grupo Vinculado al IMBICE - Grupo de Biología Estructural y Biotecnología - Universidad Nacional de Quilmes - GBEyB | Universidad Nacional de La Plata. Instituto Multidisciplinario de Biología Celular. Grupo Vinculado al IMBICE - Grupo de Biología Estructural y Biotecnología - Universidad Nacional de Quilmes - GBEyB; Argentina. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología; Argentin
Diacetylenic lipids in the design of stable lipopolymers able to complex and protect plasmid DNA
Different viral and non-viral vectors have been designed to allow the delivery of nucleic acids in gene therapy. In general, non-viral vectors have been associated with increased safety for in vivo use; however, issues regarding their efficacy, toxicity and stability continue to drive further research. Thus, the aim of this study was to evaluate the potential use of the polymerizable diacetylenic lipid 1,2-bis(10,12-tricosadiynoyl)-sn-glycero-3-phosphocholine (DC8,9PC) as a strategy to formulate stable cationic lipopolymers in the delivery and protection of plasmid DNA. Cationic lipopolymers were prepared following two different methodologies by using DC8,9PC, 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC), and the cationic lipids (CL) 1,2-dioleoyl-3-trimethylammonium-propane (DOTAP), stearylamine (SA), and myristoylcholine chloride (MCL), in a molar ratio of 1:1:0.2 (DMPC:DC8,9PC:CL). The copolymerization methodology allowed obtaining cationic lipopolymers which were smaller in size than those obtained by the cationic addition methodology although both techniques presented high size stability over a 166-day incubation period at 4C. Cationic lipopolymers containing DOTAP or MCL were more efficient in complexing DNA than those containing SA. Moreover, lipopolymers containing DOTAP were found to form highly stable complexes with DNA, able to resist serum DNAses degradation. Furthermore, neither of the cationic lipopolymers (with or without DNA) induced red blood cell hemolysis, although metabolic activity determined on the L-929 and Vero cell lines was found to be dependent on the cell line, the formulation and the presence of DNA. The high stability and DNA protection capacity as well as the reduced toxicity determined for the cationic lipopolymer containing DOTAP highlight the potential advantage of using lipopolymers when designing novel nonviral carrier systems for use in in vivo gene therapy. Thus, this work represents the first steps toward developing a cationic lipopolymer-based gene delivery system using polymerizable and cationic lipids.Instituto Multidisciplinario de Biología Celula
Diacetylenic lipids in the design of stable lipopolymers able to complex and protect plasmid DNA
Different viral and non-viral vectors have been designed to allow the delivery of nucleic acids in gene therapy. In general, non-viral vectors have been associated with increased safety for in vivo use; however, issues regarding their efficacy, toxicity and stability continue to drive further research. Thus, the aim of this study was to evaluate the potential use of the polymerizable diacetylenic lipid 1,2-bis(10,12-tricosadiynoyl)-sn-glycero-3-phosphocholine (DC8,9PC) as a strategy to formulate stable cationic lipopolymers in the delivery and protection of plasmid DNA. Cationic lipopolymers were prepared following two different methodologies by using DC8,9PC, 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC), and the cationic lipids (CL) 1,2-dioleoyl-3-trimethylammonium-propane (DOTAP), stearylamine (SA), and myristoylcholine chloride (MCL), in a molar ratio of 1:1:0.2 (DMPC:DC8,9PC:CL). The copolymerization methodology allowed obtaining cationic lipopolymers which were smaller in size than those obtained by the cationic addition methodology although both techniques presented high size stability over a 166-day incubation period at 4C. Cationic lipopolymers containing DOTAP or MCL were more efficient in complexing DNA than those containing SA. Moreover, lipopolymers containing DOTAP were found to form highly stable complexes with DNA, able to resist serum DNAses degradation. Furthermore, neither of the cationic lipopolymers (with or without DNA) induced red blood cell hemolysis, although metabolic activity determined on the L-929 and Vero cell lines was found to be dependent on the cell line, the formulation and the presence of DNA. The high stability and DNA protection capacity as well as the reduced toxicity determined for the cationic lipopolymer containing DOTAP highlight the potential advantage of using lipopolymers when designing novel nonviral carrier systems for use in in vivo gene therapy. Thus, this work represents the first steps toward developing a cationic lipopolymer-based gene delivery system using polymerizable and cationic lipids.Instituto Multidisciplinario de Biología Celula
- …