3,300 research outputs found
A Moral Framework for Understanding of Fair ML through Economic Models of Equality of Opportunity
We map the recently proposed notions of algorithmic fairness to economic
models of Equality of opportunity (EOP)---an extensively studied ideal of
fairness in political philosophy. We formally show that through our conceptual
mapping, many existing definition of algorithmic fairness, such as predictive
value parity and equality of odds, can be interpreted as special cases of EOP.
In this respect, our work serves as a unifying moral framework for
understanding existing notions of algorithmic fairness. Most importantly, this
framework allows us to explicitly spell out the moral assumptions underlying
each notion of fairness, and interpret recent fairness impossibility results in
a new light. Last but not least and inspired by luck egalitarian models of EOP,
we propose a new family of measures for algorithmic fairness. We illustrate our
proposal empirically and show that employing a measure of algorithmic
(un)fairness when its underlying moral assumptions are not satisfied, can have
devastating consequences for the disadvantaged group's welfare
Improved development to blastocyst of ovine nuclear transfer embryos reconstructed during the presumptive S-phase of enucleated activated oocytes
Effective temperature of active matter
We follow the dynamics of an ensemble of interacting self-propelled motorized
particles in contact with an equilibrated thermal bath. We find that the
fluctuation-dissipation relation allows for the definition of an effective
temperature that is compatible with the results obtained using a tracer
particle as a thermometer. The effective temperature takes a value which is
higher than the temperature of the bath and it is continuously controlled by
the motor intensity
On the tectonic evolution of the Tyrrhenian basin: new data from detrital zircons sampled in the Sardinia-Corsica Block and in the Calabria-Peloritain Arc
An Adaptive Cognitive Sensor Node for ECG Monitoring in the Internet of Medical Things
The Internet of Medical Things (IoMT) paradigm is becoming mainstream in multiple clinical trials and healthcare procedures. Cardiovascular diseases monitoring, usually involving electrocardiogram (ECG) traces analysis, is one of the most promising and high-impact applications. Nevertheless, to fully exploit the potential of IoMT in this domain, some steps forward are needed. First, the edge-computing paradigm must be added to the picture. A certain level of near-sensor processing has to be enabled, to improve the scalability, portability, reliability and responsiveness of the IoMT nodes. Second, novel, increasingly accurate data analysis algorithms, such as those based on artificial intelligence and Deep Learning, must be exploited. To reach these objectives, designers, and programmers of IoMT nodes, have to face challenging optimization tasks, in order to execute fairly complex computing tasks on low-power wearable and portable processing systems, with tight power and battery lifetime budgets. In this work, we explore the implementation of a cognitive data analysis algorithm, based on a convolutional neural network trained to classify ECG waveforms, on a resource-constrained microcontroller-based computing platform. To minimize power consumption, we add an adaptivity layer that dynamically manages the hardware and software configuration of the device to adapt it at runtime to the required operating mode. Our experimental results show that adapting the node setup to the workload at runtime can save up to 50% power consumption. Our optimized and quantized neural network reaches an accuracy value higher than 97% for arrhythmia disorders detection on MIT-BIH Arrhythmia dataset
Monitoring the microtubule nucleation dynamics of sperm centriole after IFV and ICSI in sheep zygotes.
Intracytoplasmic sperm injection (ICSI) is an assisted reproductive (ART) technique that is less efficient in ruminant, comparing to other species. In mammals, the spermatozoa proximal centriole nucleates the microtubule and generates the functional cell centriole of the resulting organism. Our study aimed to investigate eventual difference in the centriole microtubular nucleation in ICSI fertilized oocytes, comparing to control In Vitro Fertilized ones (IVF). In fact, we made the hypothesis that the tail severing step achieved in our ICSI protocol through applying a few piezo pulses, might mechanically damage the proximal centriole. On this basis, Sheep oocytes were in vitro maturated (IVM) for 24 h then were injected by piezo-pulsed spermatozoa, chemically activated by 5 min of incubation with 5 mg/ml ionomycin, washed in H199 for 5 min and cultured in 50 ”l drops of Synthetic Oviductal Fluid (SOF) with estrus sheep serum and 16 ”M isoproterenol, covered by mineral oil. Fertilization has been arrested around 5h after ICSI, and the presumptive zygotes were processed for immunological detection of tubulin. Zona Pellucida (ZP) was removed with a combined treatment of acid Tyrode and trypsin and zygotes were then fixed with 4% paraformaldehyde (pH7.2) and permeabilized by 0.5% Triton X-100, for 20 min each. Microtubular nucleation was assessed with anti-α-tubulin immunofluorescence under confocal microscopy. No difference was noticed in the dynamics and timing of sperm microtubular aster nucleation, that started around 5h post ICSI (5h30). Therefore, we conclude that abnormal microtubular nucleation by the centriole is not responsible for the low development of ICSI fertilized sheep oocytes
25th ANNIVERSARY OF CLONING BY SOMATIC-CELL NUCLEAR TRANSFER: Scientific and technological approaches to improve SCNT efficiency in farm animals and pets
The birth of Dolly through somatic cell nuclear transfer (SCNT) was a major scientific breakthrough of the last century. Yet, while significant progress has been achieved across the technics required to reconstruct and in vitro culture nuclear transfer embryos, SCNT outcomes in terms of offspring production rates are still limited. Here, we provide a snapshot of the practical application of SCNT in farm animals and pets. Moreover, we suggest a path to improve SCNT through alternative strategies inspired by the physiological reprogramming in male and female gametes in preparation for the totipotency required after fertilization. Almost all papers on SCNT focused on nuclear reprogramming in the somatic cells after nuclear transfer. We believe that this is misleading, and even if it works sometimes, it does so in an uncontrolled way. Physiologically, the oocyte cytoplasm deploys nuclear reprogramming machinery specifically designed to address the male chromosome, the maternal alleles are prepared for totipotency earlier, during oocyte nuclear maturation. Significant advances have been made in remodeling somatic nuclei in vitro through the expression of protamines, thanks to a plethora of data available on spermatozoa epigenetic modifications. Missing are the data on large-scale nuclear reprogramming of the oocyte chromosomes. The main message our article conveys is that the next generation nuclear reprogramming strategies should be guided by insights from in-depth studies on epigenetic modifications in the gametes in preparation for fertilization
The impaired development of sheep ICSI derived embryos is not related to centriole dysfunction
While intracytoplasmic sperm injection (ICSI) is an asset in human Assisted Reproduction Technologies (ART), its outcomes, in terms of blastocyst, is still unacceptably low in ruminants. The picture typically found in ICSI derived bovine and ovine embryos is an asymmetry between a high activation rate, marked by a pronuclear development, and a low first cleavage rate. Abnormal centriole function has been indicated as a possible factor which undermines embryonic development following ICSI, especially when Freeze Dried spermatozoa (FD) are used. In order to verify the hypothesis that centriole dysfunction might be responsible for low ICSI outcomes in sheep, we have investigated micro-tubular dynamics, markedly aster nucleation, in fertilized sheep zygotes by ICSI with frozen/thawed (FT) and FD spermatozoa; In Vitro Fertilized (IVF) sheep oocytes were used as control. The spermatozoa aster nucleation was assessed at different time points following ICSI and IVF by immune-detection of α-tubulin. Pronuclear stage, syngamy and embryo development were assessed. No difference was noticed in the timing of aster nucleation and microtubule elongation in ICSI-FT derived embryos with control IVF ones, while a delay was recorded in ICSI-FD ones. The proportion of 2-pronuclear stage zygotes was similar in ICSI-FT and ICSI-FD (47% and 53%, respectively), both much lower comparing the IVF ones (73%). Likewise, syngamy was observed in a minority of both ICSI groups (28.5% vs 12.5% in ICSI-FT/FD respectively) comparing to IVF controls (50%), with a high number of zygotes blocked at the 2-pronuclear stage (71.5% vs 87.5% respectively). While no significant differences were noticed in the cleavage rate between ICSI-FD, ICSI-FT and IVF groups (31%, 34% and 44%) respectively, development to blastocyst stage was markedly compromised in both ICSI groups, especially with FD spermatozoa (10% in ICIS-FD and 19% in ICSI-FT vs 33% in IVF (P < 0.005, ICSI-FD vs IVF and P < 0.05, IVF vs ICSI-FT, respectively). Hence, here we have demonstrated that the reduced cleavage, and the ensuing impaired development to blastocysts stage of ICSI derived sheep embryos is not related to centriole dysfunction, as suggested by other authors. The major recorded problem is the lack of syngamy in ICSI derived zygotes, an issue that should be addressed in further studies to improve ICSI procedure in sheep embryos
Legume-Rhizobia Relationship in the Nitrogen Fixation of a New Mediterranean Pasture Legume (Biserrula Pelecinus L.)
Biserrula pelecinus (biserrula) is a pasture legume of Mediterranean climates. Because of its ability to survive on acidic and infertile soils, it has been introduced to southern Australia as a potential alternative or companion plant to serradella and subterranean clover. The successful introduction of this species will be reliant upon the selection of an appropriate inoculant strain of its root-nodule bacteria and understanding of its ecology. A selection of five rhizobial strains isolated from biserrula nodules collected in Sardinia and Greece were examined for their ability to nodulate and fix nitrogen with 3 genotypes of biserrula. Although all rhizobial strains nodulated all host genotypes of biserrula, great variability in capacity to fix nitrogen was evident. Distinct PCR amplification profiles were generated for individual rhizobial strains which confirmed the phenotypic variability of the strains. Attention needs to be given to the large host-strain variability for nitrogen fixation in this symbiosis before proceeding with agronomic evaluation
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