Multicasting Optical Reconfigurable Switch

Artificial Intelligence (AI) demands large data flows within datacenters, heavily relying on multicasting data transfers. As AI models scale, the requirement for high-bandwidth and low-latency networking compounds. The common use of electrical packet switching faces limitations due to optical-electrical-optical conversion bottlenecks. Optical switches, while bandwidth-agnostic and low-latency, suffer from having only unicast or non-scalable multicasting capability. This paper introduces an optical switching technique addressing this challenge. Our approach enables arbitrarily programmable simultaneous unicast and multicast connectivity, eliminating the need for optical splitters that hinder scalability due to optical power loss. We use phase modulation in multiple layers, tailored to implement any multicast connectivity map. Phase modulation also enables wavelength selectivity on top of spatial selectivity, resulting in an optical switch that implements space-wavelength routing. We conducted simulations and experiments to validate our approach. Our results affirm the concept's feasibility, effectiveness, and scalability, as a multicasting switch by experimentally demonstrating 16 spatial ports using 2 wavelength channels. Numerically, 64 spatial ports with 4 wavelength channels each were simulated, with approximately constant efficiency (< 3 dB) as ports and wavelength channels scale.Comment: 17 pages, 4 figures, articl

Nonlinear Processing with Linear Optics

Deep neural networks have achieved remarkable breakthroughs by leveraging multiple layers of data processing to extract hidden representations, albeit at the cost of large electronic computing power. To enhance energy efficiency and speed, the optical implementation of neural networks aims to harness the advantages of optical bandwidth and the energy efficiency of optical interconnections. In the absence of low-power optical nonlinearities, the challenge in the implementation of multilayer optical networks lies in realizing multiple optical layers without resorting to electronic components. In this study, we present a novel framework that uses multiple scattering that is capable of synthesizing programmable linear and nonlinear transformations concurrently at low optical power by leveraging the nonlinear relationship between the scattering potential, represented by data, and the scattered field. Theoretical and experimental investigations show that repeating the data by multiple scattering enables non-linear optical computing at low power continuous wave light.Comment: 20 pages, 9 figures and 1 tabl

What influences women’s contraceptive choice? A cross-sectional study from Turkey

Objectives: In our study, we tried to investigate the determinants of women’s choices about contraception with the aim of discovering whether or not there is a difference in their preferences before and after consultation with a gynaecologist. Material and methods: A total of 1058 women were enrolled. They were given detailed information regarding contraception and contraceptive methods. Subsequently, a survey which was made of 21 questions was administered. Results: Contraceptive counselling significantly changed the contraceptive choice of women. However, influences from social media and friends, their partners and religious belief affected their contraceptive choices. Significant differences in contraceptive choice were observed when women were categorized according to their marital status, education level, household income, age, and number of children. Conclusions: Although contraceptive counselling influenced Turkish women’s choices, there were still other determinants like social media and input from outside sources such as clerics and husbands, which should be overcome

Structure and Giant Inverse Magnetocaloric Effect of Epitaxial Ni-Co-Mn-Al Films

The structural, magnetic, and magnetocaloric properties of epitaxial Ni-Co-Mn-Al thin films with different compositions have been studied. The films were deposited on MgO(001) substrates by co-sputtering on heated substrates. All films show a martensitic transformation, where the transformation temperatures are strongly dependent on the composition. The structure of the martensite phase is shown to be 14M. The metamagnetic martensitic transformation occurs from strongly ferromagnetic austenite to weakly magnetic martensite. The structural properties of the films were investigated by atomic force microscopy and temperature dependent X-ray diffraction. Magnetic and magnetocaloric properties were analyzed using temperature dependent and isothermal magnetization measurements. We find that Ni$_{41}$Co$_{10.4}$Mn$_{34.8}$Al$_{13.8}$ films show giant inverse magnetocaloric effects with magnetic entropy change of 17.5\,J\,kg$^{-1}$K$^{-1}$ for $\mu_0 \Delta H=5\,\text{T}$.Comment: 8 pages, 8 figure

The prognostic value of arterial stiffness in systolic heart failure

Background: Increased arterial stiffness is an indicator of mortality. This study consists of an 18-month follow-up of the mortality in advanced heart failure patients with increased arterial stiffness.Methods: The study followed up 98 patients with a diagnosis of heart failure in NYHA class III and IV (76 males, 22 females and mean age of 60 ± 12 years) with a left ventricular ejection fraction ≤ 35% as determined by the Simpson method. Augmentation index (Aix) and pulse wave propagation velocity (PWV) parameters were used as indicators of arterial stiffness. Aix and PWV values were measured by arteriography.Results: 36 patients died. Both Aix and PWV were powerful determinants of mortality, independent of other prognostic variables (p = 0.013, OR: 0.805; p = 0.025, OR: 0.853). A cutoff value for Aix of –14.33 gave 91.2%, 80.3% sensitivity and specificity. A cutoff value for PWVof 11.06 gave 82.4%, 65.4% sensitivity and specificity mortality was predicted. Left ventricular ejection fraction (p = 0.008, OR: 0.859) and B-type natriuretic peptide (p = 0.01, OR: 0.833) was the other independent determinant of mortality. A significant difference was found inboth Aix and PWV between the compensated measurements and decompensated heart failure measurements made in 70 patients (p = 0.035, p = 0.048).Conclusions: Measurement of arterial stiffness is a convenient, inexpensive and reliable method for predicting mortality in patients with advanced heart failure

Comparison of two different antibiotic regimens for the prophylaxisis of cases with preterm premature rupture of membranes: a randomized clinical trial

Objectives: The aim of the study was to assess the effect of 1 g ampicillin prophylactic dosage whether it is as effective as the dosage of 2 g to prevent maternal and neonatal morbidity in a randomized manner. Materials and methods: One hundred and fourty eight singleton pregnant women with preterm premature rupture of membranes between 21 and 33 weeks of gestation were followed-up during the study period in our institution. We com­pared the efficacy of two different different dosages of ampicillin. The study population was randomized into 2 groups. In the group 1, 1 g of intravenous ampicillin was given every 6 hours. In the group 2, 2 g of intravenous ampicillin was given every 6 hours. Results: There was no significant difference between groups interms of fetal complications (RDS, icterus, mortality, sepsis, transient tachypnea of newborn and the pneumonia), rate of intensive care unit admission, fetal gender, fever, rate of clinical chorioamnionitis, high white blood cell count and the CRP, rate of cases &lt; 30 weeks (p &gt; 0.05). There was a significant differ­ence between the groups for the rate of previous preterm premature rupture of membranes history, steroid administration and the need for tocolysis (p &lt; 0.05). Conclusions: Although antibiotics seems to be innocent, several side effects have been introduced. It is reasonable to use the lowest dosages in shortest period in order to minimize these unwanted effects

Forward-Forward Training of an Optical Neural Network

Neural networks (NN) have demonstrated remarkable capabilities in various tasks, but their computation-intensive nature demands faster and more energy-efficient hardware implementations. Optics-based platforms, using technologies such as silicon photonics and spatial light modulators, offer promising avenues for achieving this goal. However, training multiple trainable layers in tandem with these physical systems poses challenges, as they are difficult to fully characterize and describe with differentiable functions, hindering the use of error backpropagation algorithm. The recently introduced Forward-Forward Algorithm (FFA) eliminates the need for perfect characterization of the learning system and shows promise for efficient training with large numbers of programmable parameters. The FFA does not require backpropagating an error signal to update the weights, rather the weights are updated by only sending information in one direction. The local loss function for each set of trainable weights enables low-power analog hardware implementations without resorting to metaheuristic algorithms or reinforcement learning. In this paper, we present an experiment utilizing multimode nonlinear wave propagation in an optical fiber demonstrating the feasibility of the FFA approach using an optical system. The results show that incorporating optical transforms in multilayer NN architectures trained with the FFA, can lead to performance improvements, even with a relatively small number of trainable weights. The proposed method offers a new path to the challenge of training optical NNs and provides insights into leveraging physical transformations for enhancing NN performance

An in-vivo pilot study into the effects of FDG-mNP in cancer in mice

Purpose Previously, fluorodeoxy glucose conjugated magnetite nanoparticles (FDG-mNPs) injected into cancer cells in conjunction with the application of magnetic hyperthermia have shown promise in new FDG-mNPs applications. The aim of this study was to determine potential toxic or unwanted effects involving both tumour cells and normal tissue in other organs when FDG-mNPs are administered intravenously or intratumourally in mice. Materials and methods FDG-mNPs were synthesized. A group of six prostate-tumour bearing mice were injected with 23.42 mg/ml FDG-mNPs (intravenous injection, n = 3; intratumoural injection into the prostate tumour, n = 3). Mice were euthanized and histological sampling of tissue was conducted for the prostate tumour, as well as for lungs, lymph nodes, liver, kidneys, spleen, and brain, at 1 hour (n = 2) and 7 days (n = 4) post-injection. A second group of two normal (non-cancerous) mice received the same injection intravenously into the tail vein and were euthanised at 3 and 6 months post-injection, respectively, to investigate if FDG-mNPs remained in organs at those time points. Results In prostate-tumour bearing mice, FDG-mNPs concentrated in the prostate tumour, while relatively small amounts were found in the organs of other tissues, particularly the spleen and the liver; FDG-mNP concentrations decreased over time in all tissues. In normal mice, no detrimental effects were found in either mouse at 3 or 6 months. Conclusion Intravenous or intratumoural FDG-mNPs can be safely administered for effective cancer cell destruction. Further research on the clinical utility of FDG-mNPs will be conducted by applying hyperthermia in conjunction with FDG-mNPs in mice