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Comprehensive Raman fingerprinting and machine learning-based classification of 14 pesticides using a 785 nm custom Raman instrument
No full textRaman spectroscopy enables fast, label-free, qualitative, and quantitative observation of the physical and chemical properties of various substances. Here, we present a 785 nm custom-built Raman spectroscopy instrument designed for sensing applications in the 400–1700 cm−1 spectral range. We demonstrate the performance of the instrument by fingerprinting 14 pesticide reference samples with over twenty technical repeats per sample. We present molecular Raman fingerprints of the pesticides comprehensively and distinguish similarities and differences among them using multivariate analysis and machine learning techniques. The same pesticides were additionally investigated using a commercial 532 nm Raman instrument to see the potential variations in peak shifts and intensities. We developed a unique Raman fingerprint library for 14 reference pesticides, which is comprehensively documented in this study for the first time. The comparison shows the importance of selecting an appropriate excitation wavelength based on the target analyte. While 532 nm may be advantageous for certain compounds due to resonance enhancement, 785 nm is generally more effective for reducing fluorescence and achieving clearer Raman spectra. By employing machine learning techniques like the Random Forest Classifier, the study automates the classification of 14 different pesticides, streamlining data interpretation for non-experts. Applying such combined techniques to a wider range of agricultural chemicals, clinical biomarkers, or pollutants could provide an impetus to develop monitoring technologies in food safety, diagnostics, and cross-industry quality control applications
Completely regular codes and equitable partitions
No full textThis chapter contains some background material on equitable partitions (perfect colorings) and completely regular codes, including a survey of known results and some original results. Section 1.1 contains the main definitions related to the theory of completely regular codes and important correspondences between defined objects. Section 1.2 describes known properties of equitable partitions. In Section 1.3, we consider some very general ways to construct equitable partitions. In Section 1.4, we consider classes of combinatorial objects (mostly, classes of objects that are optimal in terms of a certain bound on their parameters) that are equivalent to equitable partitions, i.e., can be alternatively defined as a cell of an equitable partition with special parameters. Section 1.5 contains a small survey of results on completely regular codes in distance-regular graphs different from Hamming, Johnson, Grassmann, and Doob graphs. The following results of this section are new, up to our knowledge: Theorem 1.1 (generalization of Delsarte's definition of completely regular codes to non-distance-regular graphs), Lemma 1.4 (generalized correlation-immunity bound for T-designs), Theorems 1.2 and 1.3 (a new necessary condition on the existence of equitable partitions: a triangle inequality for eigenvectors of the quotient matrix), Lemma 1.7 (a sufficient condition for the strict monotonicity of an intersection array), Theorem 1.4 (strong distance invariance of some combinatorial designs), Theorem 1.6 (generalized Bierbrauer–Friedman bound), the complete list of parameters of completely-regular codes in cubic distance-regular graphs in Section 1.5 (it was known earlier only for some of these graphs). Some other results, e.g., Propositions 1.33 and 1.58, are more-or-less straightforward consequences of the general theory and might be known in the folklore. The content of this chapter is limited by the knowledge and expertize of its authors, and some deep results on completely regular codes related to the theory of association schemes (for example, most of the results of [62]) are not mentioned here
Quantum models of consciousness from a quantum information science perspective
No full textThis perspective explores various quantum models of consciousness from the viewpoint of quantum information science, offering potential ideas and insights. The models under consideration can be categorized into three distinct groups based on the level at which quantum mechanics might operate within the brain: those suggesting that consciousness arises from electron delocalization within microtubules inside neurons, those proposing it emerges from the electromagnetic field surrounding the entire neural network, and those positing it originates from the interactions between individual neurons governed by neurotransmitter molecules. Our focus is particularly on the Posner model of cognition, for which we provide preliminary calculations on the preservation of entanglement of phosphate molecules within the geometric structure of Posner clusters. These findings provide valuable insights into how quantum information theory can enhance our understanding of brain functions
Artificially weaved textile-like surface micromachined graphene-polymer flexible bioelectrodes
No full textDry, flexible, and self-adhesive sensors are critical enablers for wearable, long-term biosignal recording devices. Here, an ultra-thin, flexible textile-like microstructured electrode with self-adhesive abilities is presented for conformal attachment and long-term electrocardiography (ECG) recording. The reported electrode is manufactured using a spin-coatable and electron-beam sensitive formulation of poly (methyl methacrylate) (PMMA) resist, also commonly known as acrylic, which is at the same time a widely-employed material in the textile industry. The textile-like structure of the bioelectrodes with a linewidth of 100 µm and gap size of 100 µm is achieved by patterning PMMA through oxygen plasma and a hard mask layer without requiring complex and expensive e-beam lithography (EBL) processes. Graphene oxide (GO) is introduced to the electrodes as active material followed by a reduction step using eco-friendly pure vitamin C (L-ascorbic acid). The functionality of the reported electrodes is benchmarked against pre-gelled wet Ag/AgCl electrodes, comparing their signal quality and skin-electrode impedance, and achieving a correlation score of 98.84%. Furthermore, it is demonstrated that the electrodes are flexible, water resistant, and can be used multiple times; rendering them suitable for wearable electronics purposes even during intense physical activities both in dry and wet environments
Bandwidth expansion in n-fold frequency multiplier: is it N or √N?
No full textFrequency up-conversion is an essential step in wireless communication systems. Meanwhile, frequency multipliers are increasingly becoming an integral part of communication chains operating at millimeter-wave (mmWave) and sub-terahertz (sub-THz) frequencies. They offer a viable alternative to traditional mixers, which are highly constrained by their instability and high phase noise at such high frequencies. Despite the frequency multipliers’ advantages and the fact that they are commonly recommended by hardware designers, there is a lack of comprehensive theoretical guidelines detailing their impact on digital communications. One key aspect is their tendency to induce bandwidth expansion, a phenomenon not observed with mixers. When an N-fold frequency multiplier is used, a common practice among hardware designers is to allocate a bandwidth scaled by a multiple of N, which is deemed large enough to keep signals integrity. We provide an analytical framework to quantify the exact scaling factor of the bandwidth expansion. Contrary to common belief, we show that the bandwidth expansion scales as √N, using three counterexamples, namely Gaussian, Sinc, and raised cosine pulses. These findings can help conserve radio resources and further decrease the noise effect
Dynamics and stability of high axial depth milling of thin-walled parts
No full textIn finish milling of thin-wall parts, chatter stability is governed by the dynamic response of both the milling tool and workpiece. In the literature, most of the stability models consider single-point contact with shallow axial cutting depths, i.e., point milling, where the mode shape dependent dynamic response is ignorable. On the other hand, as far as high depth milling processes, i.e., flank milling, are concerned there is a line of contact along the axial direction of the milling tool, rather than a single-point of contact. Consequently, mode shape dependent dynamic response turns out to be significant for accurate prediction of stability limits. In this study, the axial variation in the frequency response function (FRF) of the milling system is considered in prediction of stability diagrams. The novel contribution of this study is the experimental verification of the proposed stability model by using a practical workpiece dynamics model. In this respect, the validity of the proposed model was examined under various cases to provide an understanding to develop chatter-free machining strategies, and to demonstrate significant advantage of considering the mode shape dependent FRF variation along the axial direction
Checks and balances and institutional gridlock: implications for authoritarianism
No full textRecently, the world saw a wave of elected leaders attack democracy. Why do people support leaders who remove checks and balances? I argue that aspiring autocrats gain more popular support when they present these institutions as obstacles to getting things done. In doing so, they exploit a critical tension between the possibility of gridlock and the abuse of power, which is inherent in democratic institutions. Using cross-national data and leveraging an original survey experiment from Turkey, I show that effective checks and balances decrease democracy satisfaction and that aspiring autocrats gain more popular support when they present these institutions as obstacles. More interestingly, respondents perceive the aspiring autocrats' gridlock justification to dismantle checks and balances as a pro-democratic attempt to remove the obstacles to a policy-responsive regime. These results show that aspiring autocrats exploit the tension in democracies, making it harder for citizens to perceive the threat they face
Mineral profiling of Turkish wheat genetic resources unveiled their conserved potential for biofortification in combating hidden hunger
No full textMicronutrient deficiencies, also known as hidden hunger, pose a threat to the global population alongside food scarcity. Wheat is a staple food for a huge population and available commercial cultivars generally lack sufficient mineral contents. Crop wild relatives harbor novel variation crucial for crop improvement programs including biofortification. The southeastern region of Türkiye is blessed with diverse wheat germplasm. This study aimed to explore the mineral content diversity in different wheat species germplasm; i.e., Triticum boeoticum, T. dicoccoides, T. durum, and T. aestivum. Various mineral elements; i.e., Zn, Fe, K, P, S, Mg, Ca, and Mn were investigated in the grains of 192 genotypes. The analysis of variance (ANOVA) results showed highly significant genotypic effects of all traits in T. boeoticum, T. dicoccoides, and T. durum. The highest seed Zn concentration (77.8 mg kg−1) was found in T. boeoticum genotype-36 and the lowest (24.9 mg kg−1) was recorded in genotype T. aestivum genotype-4. A total of 16 genotypes belonging to T. dicoccoides had > 50 mg kg−1 grain Zn content and can be a potential source for developing Zn-enriched durum wheat cultivars. Maximum Fe content (109 mg kg−1) was found in T. dicoccoides genotype-11, while minimum (29 mg kg−1) was recorded in T. durum genotype-55. Zinc and Fe contents in T. boeoticum and T. dicoccoides genotypes were found more than twice as reported previously with T. durum and bread wheat germplasm. Grain Zn contents showed a highly significant and positive correlation with the various studied traits. Principal components analysis (PCA) and biplot confirmed that first two principal components accounted for a total of 79.14% variation. The present investigation confirmed that available bread wheat's genetic resources have low genetic diversity and its wild relatives conserve unexplored variation that can be helpful for wheat biofortification
Dyadic daily examination of repetitive thought and well-being in bereaved parents
No full textWe aimed to investigate the bidirectional associations of repetitive thought (i.e., rumination, yearning) with individual (grief levels, depressive symptoms) and relational well-being in bereaved parents who lost their child during pregnancy, labor, or afterward. The Response Styles Theory posits a reciprocal link between repetitive thought and well-being. However, past studies provided mixed evidence for this claim for individual well-being, and no study has yet examined this claim for relational well-being. Moreover, reciprocal associations have not been investigated within dyads. In total, 483 Turkish bereaved parents (228 couples, 27 individuals) participated in a 7-day dyadic diary. We conducted Random Intercept Cross- Lagged Panel Model analyses. The study yielded limited evidence for the lagged daily effects in the whole sample: bereaved parents’ higher-than-usual rumination predicted lower relational well-being in the partner the next day, but no lagged link appeared for individual well-being. Yet, sensitivity analyses revealed that higher-than-usual rumination predicted increased grief and reduced relational well-being in the partners of people who are recently bereaved or have experienced pregnancy loss. At the between-person level, bereaved parents’ average repetitive thought was related to their own and their partner’s individual but not relational well-being. Findings indicate that bereaved parents’ interdependence in repetitive thought and well-being is more evident at the between-person level for individual well-being. Still, daily rumination is a risk factor for the partners’ relational well-being. Both the persistent repetitive thought and daily fluctuations in rumination and well-being should be considered in supporting bereaved parents during their joint experience
Quantum sensing to monitor changes in free radical generation by intracellular vesicles of polarized macrophages
No full textMacrophages are immune cells crucial in clearing our tissues from bacteria, viruses, dying cells, cell debris and other waste products. They also regulate inflammation by differentiating from non-activated (M0) cells into macrophages that initiate inflammation (pro-inflammatory macrophages, M1), or resolve inflammation (anti-inflammatory macrophages, M2). One of their key functions is to ingest pathogens within vesicles where they are degraded. The production of free radical (FR) plays an important role in this degradation process but also in macrophage differentiation and signaling. Here we used diamond-based quantum sensing to track free radical changes in vesicles with nanoscale resolution. We further followed the oxidative stress status, through free radical measurement during the macrophage activation process. We found that the three macrophage subtypes differed significantly in free radical generation in their vesicles. Additionally, we showed that the FR generation evolves over time in the different subtypes. We observed a 50 % increase in radical production in M0 after 24 h compared to the T1 values measured after 4 h of cell culture, a decrease in M1 and constant radical levels in M2 macrophages. Statement of significance: Here we use quantum sensing for the first time to investigate the role that free radicals play in immune cells when they differentiate to fulfill their functions in the immune system. We were able to measure free radical generation specifically in vesicles while the macrophages differentiated