Spectroscopic methods and chemometrics/machine learning offer a fast, easy, and simple approach to detect adulteration in milk. The aim of this study was to evaluate the performance of several commonly used classification and regression algorithms for detecting milk adulteration, using added water as the adulterant, based on near-infrared (NIR) spectroscopy. Different water/milk mixtures containing 1% to 40% added water were prepared and analyzed. Supervised classification algorithms such as linear discriminant analysis (LDA), partial least squares discriminant analysis (PLS-DA), and support vector machines discriminant analysis (SVM-DA) were applied. Subsequently, supervised regression algorithms for quantitative detection, such as partial least squares regression (PLSR) and support vector regression (SVR), were evaluated. The PLS-DA models using autoscaling (AS) and standard normal variate (SNV) showed the best performance for validation in terms of sensitivity (SEN), specificity (SPE), accuracy (ACC), and error with values of 0.953, 0.850, 0.920, 0.098, and 0.930, 0.950, 0.937, 0.060, respectively. For quantitative determination, the best performance was achieved using partial least squares regression (PLSR) combined with standard normal variate (SNV) preprocessing of the spectral data. This model exhibited a validation root mean square error (RMSECV) of 3.912, a prediction Root Mean Square Error (RMSEP) of 2.117, a residual predictive deviation (RPD) of 6.15, and a coefficient of determination for prediction (R²P) of 0.972. These results demonstrate that the combination of NIR spectroscopy with chemometric and machine learning techniques, such as PLSR, is suitable for the quantification of added water in raw milk samples.
Triaenodes corazonus sp. nov. urn:lsid:zoobank.org:act: 8F8A77CF-5C0C-4773-81D2-825ED26FDEB4 Fig. 2A–E Diagnosis. This species shares all the characteristics that define members of the Neotropical clade of Triaenodes as discussed in detail by Yang & Morse (1993) and Holzenthal & Andersen (2004). These include the simplified inferior appendage which lacks the mesal baso-dorsal process and the lateral baso-dorsal process. The absence of these structures, together with the well-developed apicomesal lobe of the inferior appendage, are unique features of this clade within the genus. In addition, the well-developed recurved process of the inferior appendage, the structure of abdominal segments IX and X, the triangular phallobase, narrow phallicata, and long parameres, comprise a typical diagnostic morphotype for all described species of this clade (Holzenthal & Andersen 2004, figs. 5–29). However, while sharing all these common features with other Neotropical species, Triaenodes corazonus sp. nov. stands apart by the distinctive pair of prominent spine-like processes arising apicomesally from the body of the inferior appendage. Description. Forewing length 4.5–4.7 mm (n=6). Color unknown, entire specimen cleared. Tibial spur formula 1, 2, 2. Male genitalia. Segment IX anterior margin straight; pleural region along posterior margin semi-membranous, setose; tergum IX, in dorsal view, straight anteriorly, with dorsomesal papillae (Fig. 2A, B). Preanal appendage short, rounded, setose. Dorsomesal process of tergum X thumb-shaped, short, setose; tergum X, in dorsal view, widest basally, narrower apically, apex slightly excavate medially; in lateral view, triangular, apex narrow. Inferior appendage quadrate basally, short, with pair of prominent spine-like processes arising apicomesally; apicomesal lobe elongate, digitate, setose, curved mesally; recurved process strongly curved, downturned at apex, widest basally, narrowing gradually to acute, forked apex, trough-like, with long seta at mid-length and short setae apically (Fig. 2A, C). Phallobase triangular, short; endothecal membranes prominent, highly convoluted, with 3 parameres, 2 long, subequal in length, 3rd shorter; phallicata narrow, widest at base, apex very, narrow, attenuate, apex rounded in dorsal/caudal views; phallotremal sclerite not evident (Fig. 2D, E). Female, larva, pupa. Unknown. Holotype male. PANAMA, Coclé Province, Cuenca 105, La Pintada District, El Harino, Parque Nacional Omar Torrijos Herrera; Quebrada Corazones; 8.6676°N, 80.60007°W; 728 m a.s.l.; March 24, 2017; UV light trap; leg A. Cornejo, T. Ríos, E. Álvarez, E. Pérez (MUPADI). Paratypes, ibid., 3 males (UMSP); ibid., 8.67801°N, 80.60036°W; 792 m a.s.l.; 2 males (MUPADI). Distribution. Panama. Etymology. This species is named for Quebrada Corazones, a tributary of the Río Blanco and at the center of Parque Nacional Omar Torrijos Herrera where the species was collected; “corazon” in Spanish means heart or center.
In virtual education, student autonomy manifests as operational self-regulation, and critical thinking depends on isolated pedagogical practices, which highlights the need to analyze the pedagogical, technological, and institutional mediations that shape critical autonomy. The objective was to analyze how the formation of critical subjects and autonomy in higher-education virtual environments is configured, based on students’ experiences at three universities in Peru, Panama, and the Dominican Republic. A qualitative approach was adopted, using a multiple and comparative case study design. The purposive and voluntary sample consisted of 18 university students aged 18 to 25, evenly distributed between semi-structured interviews and focus groups, and content analysis of the institutional virtual platform was conducted in each context. The findings show that, across the three cases, operational autonomy predominates, centered on time management and task completion. Critical thinking emerges through debates and real-world cases, although with varying depth, with a technical emphasis in the Peru case, an argumentative emphasis in the Panama case, and a systematic emphasis in the Dominican Republic case. The platforms prioritize administrative functions, which limits reflection. Connectivity and economic inequalities affect all cases, with less impact in the Dominican Republic due to its support policies. It is concluded that the formation of critical subjects in virtual environments is not an automatic result of digitization, but rather depends on pedagogical mediations, institutional decisions, and specific social contexts.
The polarization state of light plays a central role in strong-field light–matter interactions and is widely used to probe electronic structure in solids via high-order harmonic generation (HHG). In particular, helicity-resolved HHG has been interpreted as a fingerprint of crystal symmetry and topology. Here, we demonstrate deterministic and continuous control of harmonic helicity in solids using polarization-crafted beams, formed by two orthogonally polarized pulses with a controlled time delay. By tuning this delay, the polarization state of individual harmonics can be driven from linear to circular, independent of the material under investigation. We show that this behavior is robust across systems with distinct symmetry and topology, and originates from the sub-cycle modulation of the light–matter interaction mediated by the dipole coupling. Furthermore, the orthogonal configuration allows to break the dynamical symmetry of the light-matter interaction which is manifested in the generation of otherwise forbidden harmonics under standard selection rules.. These results establish harmonic helicity as a field-controlled observable rather than a direct material fingerprint.
Symmetry governs nonlinear interactions in condensed matter systems, particularly in high-harmonic generation (HHG), the interplay between the driving field and crystal symmetries dictate the properties of the emitted harmonics. A central open question is how quantum fluctuations of light modify these symmetry-imposed selection rules in solid state systems. Here, we address this by studying the nonlinear response of graphene and Molybdenum disulfide (MoS_2) to circular polarized quantum light, where both materials with distinct rotational symmetries and corresponding classical selection rules. We show that the quantum fluctuations break the dynamical symmetry of the driving field while preserving the crystal symmetry, which enables the generation of classically forbidden harmonics by breaking the corresponding selection rules. These results establish quantum states of light as a new degree of control over harmonic generation in solids, opening routes toward all-optical symmetry engineering of the quantum optical harmonic properties towards attosecond pulse generation.
