Application of Reconfigurable All-Optical Activation Unit based on Optical Injection into Bistable Fabry-P\'{e}rot Laser in Multilayer Perceptron Neural Networks

In this paper we theoretically investigate application of a bistable Fabry-P\'{e}rot semiconductor laser under optical-injection as all-optical activation unit for multilayer perceptron optical neural networks. The proposed device is programmed to provide reconfigurable sigmoid-like activation functions with adjustable thresholds and saturation points and benchmarked on machine learning image recognition problems. Due to the reconfigurability of the activation unit, the accuracy can be increased by up to 2% simply by adjusting the control parameter of the activation unit to suit the specific problem. For a simple two-layer perceptron neural network, we achieve inference accuracies of up to 95% and 85%, for the MNIST and Fashion-MNIST datasets, respectively

Propylene glycol energy supplementation during peripartal period in dairy cows and reproduction efficiency parameters

The aim of this work was to investigate the impact of two energy supplements based on propylene glycol in dairy cows diet on ovarian and follicular morphology, conception, insemination index and length of service period. A total number of 60 Holstein Friesian dairy cows, parity between 2-8, with an average milk production of 7000 kg/305 days of lactation were divided into three experimental groups (20 dairy cows per group). The first group of dairy cows was supplemented daily with "Energy-plus" (O1 group; 200 mL propylene-glycol supplement) and the second group was supplemented with "Ketal" (O2 group; 160 mL propylene-glycol supplement), two weeks before partus until 30 days post partum. The third experimental group were non supplemented dairy cows (O3, control group). Ultrasound examination of the reproductive system using real time echo camera Falco VET 100 (ESAOTE PieMedical, Holland, B-shaped scan with linear-array endorectal 5-8 MHz probe) was conducted on every animal starting from day 40 postpartum. The diameters of the ovaries (left and right) and of the dominant follicle(s) were recorded. Ultrasound testing was repeated on day 50 and 60 postpartum only in cows which in the meantime were not inseminated. Reproduction efficiency parameters (conception rate, number of inseminations and length of service period) were recorded individually. The statistical significance of the differences between groups was tested using ANOVA with LSD test at the level of significance p<0.05, chi-square test and Kaplan-Meier survival analysis (the length of service period). There was no significant impact of the propylene glycol supplementation on the ovarian and follicular morphology at the first ultrasound examination. At the second ultrasound examination there was a significant difference between left ovarian dominant follicle diameter in the control and supplemented dairy cows (1.67±0.53 vs 1.12±0.29 and 1.11±0.35 cm, p<0.05, O3 vs O1 and O2, respectively). The cumulative percentage of conception after the first and second insemination was 60%, 81% and 25% in groups O1, O2 and O3, respectively (p<0.05, chi-square test). The insemination index was lowest in group O2 and statistically significant differences were found between groups O2 and O3 (1.69±0.79 : 3.38±1.36, respectively, p<0,05). The length of the service period was significantly (p<0.05, LSD test) shorter in the O2 group (100±35 days) compared to groups O1 and O3 (168±59 and 157±52 days, respectively), that was confirmed by the Kaplan-Meier survival analysis of days open periods. The use of propylene glycol supplement in dairy cows diet during peripartal period induced higher percentage of pregnancy rates after the first and second insemination, significantly shortened the length of the service period and reduced the insemination index

Energetska suplementacija propilen glikolom tokom peripartalnog perioda i parametri efikasnosti reprodukcije kod mlečnih krava

The aim of this work was to investigate the impact of two energy supplements based on propylene glycol in dairy cows diet on ovarian and follicular morphology, conception, insemination index and length of service period. A total number of 60 Holstein Friesian dairy cows, parity between 2-8, with an average milk production of 7000 kg/305 days of lactation were divided into three experimental groups (20 dairy cows per group). The first group of dairy cows was supplemented daily with 'Energy-plus' (O1 group; 200 mL propylene-glycol supplement) and the second group was supplemented with 'Ketal' (O2 group; 160 mL propylene-glycol supplement), two weeks before partus until 30 days post partum. The third experimental group were non supplemented dairy cows (O3, control group). Ultrasound examination of the reproductive system using real time echo camera Falco VET 100 (ESAOTE PieMedical, Holland, B-shaped scan with linear-array endorectal 5-8 MHz probe) was conducted on every animal starting from day 40 postpartum. The diameters of the ovaries (left and right) and of the dominant follicle(s) were recorded. Ultrasound testing was repeated on day 50 and 60 postpartum only in cows which in the meantime were not inseminated. Reproduction efficiency parameters (conception rate, number of inseminations and length of service period) were recorded individually. The statistical significance of the differences between groups was tested using ANOVA with LSD test at the level of significance p lt 0.05, chi-square test and Kaplan-Meier survival analysis (the length of service period). There was no significant impact of the propylene glycol supplementation on the ovarian and follicular morphology at the first ultrasound examination. At the second ultrasound examination there was a significant difference between left ovarian dominant follicle diameter in the control and supplemented dairy cows (1.67±0.53 vs 1.12±0.29 and 1.11±0.35 cm, p lt 0.05, O3 vs O1 and O2, respectively). The cumulative percentage of conception after the first and second insemination was 60%, 81% and 25% in groups O1, O2 and O3, respectively (p lt 0.05, chi-square test). The insemination index was lowest in group O2 and statistically significant differences were found between groups O2 and O3 (1.69±0.79 : 3.38±1.36, respectively, p lt 0,05). The length of the service period was significantly (p lt 0.05, LSD test) shorter in the O2 group (100±35 days) compared to groups O1 and O3 (168±59 and 157±52 days, respectively), that was confirmed by the Kaplan-Meier survival analysis of days open periods. The use of propylene glycol supplement in dairy cows diet during peripartal period induced higher percentage of pregnancy rates after the first and second insemination, significantly shortened the length of the service period and reduced the insemination index.Cilj ovog rada je bio da se ispita uticaj primene dva tipa energetskih dodataka u ishrani mlečnih krava na bazi propilen glikola na morfologiju jajnika i folikula, koncepciju, indeks osemenjavanja i dužinu servis perioda. U ogled je bilo uključeno ukupno 60 krava Holštajn Frizijske rase, u toku 2-8 laktacije, sa prosečnom proizvodnjom mleka od 7000 kg/305 dana laktacije, koje su bile podeljene u tri ogledne grupe (20 krava po grupi). Prva grupa mlečnih krava (O1) je svakodnevno suplementirana peroralnom aplikacijom 200 mL 'Energy-plus', druga grupa krava (O2) suplementirana je sa 160 mL 'Ketal-a', počevši od dve nedelje pre partusa do 30 dana nakon partusa. Treću grupu mlečnih krava (O3, kontrola) su predstavljale netretirane životinje. Ultrazvučni pregled reproduktivnog sistema vršen je sa uređajem Falco VET 100 (ESAOTE PieMedical, Holland), linearnom endorektalnom sondom od 5-8 MHz kod svake životinje najmanje dva puta počevši od 40 dana posle partusa. Ultrazvučni pregled je ponovljen sa 50 i/ili 60 dana posle partusa kod krava koje nisu u međuvremenu osemenjene. U toku svakog pregleda su registrovani prečnik oba jajnika i dominantnog folikula. Kod svake ogledne životinje su određeni parametri efikasnosti reprodukcije: stepen koncepcije, indeks osemenjavanja i servis period. Statistička značajnost razlika srednjih vrednosti dobijenih parametara određivana je ANOVA metodom i LSD testom na nivou značajnosti od p lt 0.05, hi-kvadrat testom i Kaplan-Majerovom analizom (dužina servis perioda). Rezultati prvog ultrazvučnog pregleda su ukazali da nema statistički značajnih razlika u morfologiji jajnika i dominantnog folikula između suplementiranih grupa u odnosu na kontrolnu grupu krava. Rezultati drugog ultrazvučnog pregleda su ukazali da postoji statistički značajna razlika između srednjih vrednosti prečnika dominantnog folikula na levom jajniku kod kontrolne grupe krava u odnosu na suplementirane životinje (1,67±0,53:1,12±0,29 i 1,11±0,35 cm, p lt 0.05, O3:O1 i O2). Zbirne vrednosti procenta koncepcije nakon prvog i drugog osemenjavanja bile su statistički značajno više kod suplementiranih krava u odnosu na kontrolnu grupu životinja (60% : 81% : 25%; O1:O2:O3, p lt 0,05, hi-kvadrat test). Najniža vrednost indeksa osemenjavanja je utvrđena kod ogledne grupe krava suplentirane Ketal-om (1.69±0.79), koja je bila značajno viša u odnosu na kontrolnu grupu krava (3.38±1.36, p lt 0,05). Dužina servis perioda je bila najmanja kod grupe krava suplementiranih Ketal-om (100±35 days) i značajno se razlikovala u odnosu na ostale ogledne grupe (168±59 i 157±52 dana, O1 i O2), što je potvrđeno Kaplan Majerovom analizom. Energetska suplementacija mlečnih krava propilen glikolom tokom peripartalnog perioda može dovesti do povećanja procenta gravidnih krava nakon prvog i drugog osemenjavanja, smanjenja vrednosti indeksa osemenjavanja i skraćenja dužine servis perioda

Surface-Enhanced Nitrate Photolysis on Ice

Heterogeneous nitrates photolysis is the trigger for many chemical processes occurring in the polar boundary layer and is widely believed to occur in a quasi-liquid layer (QLL) at the surface of ice. The dipole forbidden character of the electronic transition relevant to boundary layer atmospheric chemistry and the small photolysis/photoproducts quantum yields in ice (and in water) may confer a significant enhancement and interfacial specificity to this important photochemical reaction at the surface of ice. Using amorphous solid water films at cryogenic temperatures as models for the disordered interstitial air/ice interface within the snowpack suppresses the diffusive uptake kinetics thereby prolonging the residence time of nitrate anions at the surface of ice. This approach allows their slow heterogeneous photolysis kinetics to be studied providing the first direct evidence that nitrates adsorbed onto the first molecular layer at the surface of ice are photolyzed more effectively than those dissolved within the bulk. Vibrational spectroscopy allows the ~3-fold enhancement in photolysis rates to be correlated with the nitrates’ distorted intramolecular geometry thereby hinting at the role played by the greater chemical heterogeneity in their solvation environment at the surface of ice than in the bulk. A simple 1D kinetic model suggests 1-that a 3(6)-fold enhancement in photolysis rate for nitrates adsorbed onto the ice surface could increase the photochemical NO[subscript 2] emissions from a 5(8) nm thick photochemically active interfacial layer by 30%(60)%, and 2-that 25%(40%) of the NO[subscript 2] photochemical emissions to the snowpack interstitial air are released from the top-most molecularly thin surface layer on ice. These findings may provide a new paradigm for heterogeneous (photo)chemistry at temperatures below those required for a QLL to form at the ice surface

Self-consistent treatment of v-groove quantum wire band structure in no parabolic approximation

The self-consistent no parabolic calculation of a V-groove-quantum-wire (VQWR) band structure is presented. A comparison with the parabolic flat-band model of VQWR shows that both, the self-consistency and the nonparabolicity shift sub band edges, in some cases even in the opposite directions. These shifts indicate that for an accurate description of inter sub band absorption, both effects have to be taken into the account

Application of a reconfigurable all-optical activation unit based on optical injection into a bistable Fabry–Perot laser in multilayer perceptron neural networks

In this Letter, we theoretically investigate the application of a bistable Fabry–Perot semiconductor laser under optical injection as an all-optical activation unit for multilayer perceptron optical neural networks. The proposed device is programmed to provide reconfigurable sigmoid-like activation functions with adjustable thresholds and saturation points and benchmarked on machine learning image recognition problems. Due to the reconfigurability of the activation unit, the accuracy can be increased by up to 2% simply by adjusting the control parameter of the activation unit to suit the specific problem. For a simple two-layer perceptron neural network, we achieve inference accuracies of up to 95% and 85%, for the MNIST and Fashion-MNIST datasets, respectively.</p

Phase Space of Tristability in Dual Injection-Locked Fabry-Perot Laser Diodes

We investigate theoretically the case of dual injection-locking, in which the two light signals are simultaneously externally injected into the cavity of a slave Fabry-Perot laser diode. We show that dual injection-locking leads to formation of new stationary points, and potentially to optical tristability of the slave laser. We show that a region in which the slave laser exhibits three stable steady-states occurs only for sufficiently different frequency detunings of the two injection signals. Moreover, the slave laser tunability depends on the choice of injection modes, and strongly depends on the slave laser bias current, with an optimal value around 2 times threshold current

Voltammetric determination of neotame by using chitosan/nickelnanoparticles/multi walled carbon nanotubes biocomposite as a modifier

A selective and simple biosensor was preparedby immobilizing chitosan/nickelnanoparticles/multi-walledcarbon nanotubes biocomposite on the glassy carbonelectrode surface for voltammetric quantification of neo-tame. The properties and morphology of the modifiedelectrode surfaces were characterized by scanning elec-tron microscope (SEM), energy dispersive X-ray analysis(EDX). Electro oxidation of neotame on this modifiedsurface was examined through cyclic voltammetry (CV)and square wave voltammetry (SWV) techniques. Thebiocomposite modified surface (Chi/NiNPs/MWCNTs/GCE) proposed in this study showed good electrocatalyticactivity for neotame with an improved voltammetric peakcurrent at 1.004 V, unlike the bare glassy carbon electrode(GCE) surface and several other modified surfaces.Under optimum conditions, Chi/NiNPs/MWCNTs/GCEgave linear SWV responses at the range of 2 M ~ 50 Mfor neotame with 0.84 M determination limit. Thisvoltammetric sensor was successfully employed for thequantification of neotame on food samples and showedlong-term stability, advanced voltammetric behavior, andgood repeatability. Selective, accurate, and precise deter-mination of neotame highlight the importance of thiselectrode in monitoring the control of food additives andensures attract a great deal of attention

Slobodne aminokiseline u krvnom serumu kod novorođene teladi oralno tretirane zeolitom u periodu kolostralne ishrane

Oral zeolite treatement effects on the blood serum free amino acid pattern in newborn calves was investigated. The total number of 30 newborn Holstein calves of both sexes, weighting 35±3 kg (mean±SD), were immediately after parturition separated from their dams and placed in individual pens. Calves were divided in two experimental groups, 15 calves each. All calves were bottle-fed twice/ day (1.5 L/meal) during the first 48 hours after delivery, in 12 hour intervals, with their mother's first (during 24 hours postpartum) or second colostrum (at 24-48 hours postpartum), starting two hours after delivery. Zeolite suspension (20 mL, 25% suspension in distilled water) was added to every meal for treated calves. Colostrum samples were collected from six cows at 0-12h and 24h after delivery. Total and colostral whey protein concentrations were determined using the colorimetric method. Blood samples were taken from the jugular vein of calves at 6, 16, 30 and 40 hours after birth. After spontaneous coagulation at room temperature blood serum was separated and stored at -20°C until analyzed. Total protein concentration was determined by the colorimetric method. Blood serum immunoglobulin G (IgG) concentrations were determined using single radial immunodiffusion (sRID) plates. Pooled blood serum free amino acids (aspartic acid - Asp, glutamic acid - Glu, serine - Ser, histidine - His, glycine - Gly, threonine - Thr, alanine - Ala, proline - Pro, tyrosine - Tyr, arginine - Arg, valine - Val, methionine - Met, Leucine - Leu, Isoleucine - Ile, phenylalanine - Phe) were identified and quantified using high-performance liquid chromatography (HPLC, GBC Australia). Total and colostral whey protein concentrations were significantly higher in the first colostrum and decreased between 50-75% at 24-48 hours later on. Mean blood serum IgG concentration was significantly increased at 6 and 16 hours in the treated calves (26±7:20±5 and 55±15:42±13 g/L, p lt 0.05). Blood serum free amino acids (AA) first were separated at nonessential and essential AA (NEAA and EAA, respectively), both being increased at all time intervals after birth in treated calves. However, when the pooled blood serum free AA were clustered according to polarity and electrical charge and presented as relative values (% of the control group values) at the 6h there was a massive increase of polar positive (Arg, His), polar neutral (Ser, Thr, Tyr) and nonpolar neutral free AA (except Met). The minimal effect of oral zeolite treatment was on the negative polar blood serum free AA concentration (Asp and Glu).U ovom radu su izneti rezultati ispitivanja uticaja oralnog tretmana zeolitom na koncentraciju slobodnih aminokiselina u krvnom serumu kod novorođene teladi. Ispitivanje je izvršeno na ukupno 30 novorođenih teladi, oba pola, prosečne telesne mase 35±3 kg (srednja vrednost±SD), koja su neposredno nakon partusa odvojena od majke i smeštena u individualne bokseve. Telad su podeljena u dve ogledne grupe sa po 15 životinja u svakoj grupi. Sva telad su hranjena dva puta dnevno (1.5 L/obroku) u toku prvih 48 sati nakon partusa kolostrumom njihovih majki, u intervalu od 12 sati, počevši od 2 sata nakon partusa. U toku prva 24 sata telad su hranjena prvim kolostrumom (skupljen u toku prvih 24 sata) dok su u sledeća 24 sata hranjena drugim kolostrumom (skupljen u periodu od 24-48 sati nakon partusa). Tretirana grupa teladi dobijala je sa svakim obrokom suspenziju zeolita (20 mL, 25% suspenzije zeolita u destilovanoj vodi). Uzorci kolostruma uzimani su od 6 krava u periodu od 0 - 12 sati i 24 sata nakon partusa i kolorimetrijskom metodom je određivana koncentracija proteina u kolostrumu i kolostralnom mlečnom serumu. Uzorci krvi od teladi uzimani su iz v. jugularis 6, 16, 30. i 40. sata nakon partusa, nakon spontane koagulacije na sobnoj temperaturi je odvajan krvni serum i čuvan na -20°C do momenta analize. Koncentracija ukupnih proteina u uzorcima krvnog seruma teladi je određivana kolorimetrijskom metodom, a koncentracija imunoglobulina G (IgG) radioimunodifuzionim testom (sRID). Koncentracija slobodnih aminokiselina je određivana u zbirnim uzorcima krvnog seruma (aspartat - Asp, glutamat - Glu, serin - Ser, histidin - His, glicin - Gly, treonin - Thr, alanin - Ala, prolin - Pro, tirozin - Tyr, arginin - Arg, valin - Val, metionin - Met, leucin - Leu, izoleucin - Ile, fenilalanin - Phe) metodom visoko precizne tečne hromatografije (HPLC, GBC Australia). Koncentracija ukupnih proteina u kolostrumu i kolostralnom mlečnom serumu je bila statistički značajno viša u prvom kolostrumu i snižena je između 50-75% u periodu 24-48 sati nakon partusa. Srednje vrednosti koncentracije IgG u krvnom serumu 6. i 16. sata nakon partusa bile su statistički značajno više kod tretirane grupe teladi u odnosu na kontrolnu grupu životinja (26±7:20±5 i 55±15: 42±13 g/L, p lt 0.05). Koncentracija ispitivanih slobodnih neesencijalnih i esencijalnih aminokiselina u zbirnim uzorcima krvnog seruma je povišena u svim vremenskim intervalima kod tretirane grupe teladi. Najveći stepen porasta koncentracije zabeležen je kod polarnih pozitivnih (Arg, His), polarnih neutralnih (Ser, Thr, Tyr) i nepolarnih neutralnih slobodnih aminokiselina (izuzev Met). Minimalni efekat oralnog tretmana zeolitom zabeležen je u slučaju koncentracije polarnih negativnih slobodnih aminokiselina (Asp i Glu) u zbirnim uzorcima krvnog seruma tretirane grupe teladi