Nanosecond-level time synchronization of autonomous radio detector stations for extensive air showers

To exploit the full potential of radio measurements of cosmic-ray air showers at MHz frequencies, a detector timing synchronization within 1 ns is needed. Large distributed radio detector arrays such as the Auger Engineering Radio Array (AERA) rely on timing via the Global Positioning System (GPS) for the synchronization of individual detector station clocks. Unfortunately, GPS timing is expected to have an accuracy no better than about 5 ns. In practice, in particular in AERA, the GPS clocks exhibit drifts on the order of tens of ns. We developed a technique to correct for the GPS drifts, and an independent method is used to cross-check that indeed we reach a nanosecond-scale timing accuracy by this correction. First, we operate a "beacon transmitter" which emits defined sine waves detected by AERA antennas recorded within the physics data. The relative phasing of these sine waves can be used to correct for GPS clock drifts. In addition to this, we observe radio pulses emitted by commercial airplanes, the position of which we determine in real time from Automatic Dependent Surveillance Broadcasts intercepted with a software-defined radio. From the known source location and the measured arrival times of the pulses we determine relative timing offsets between radio detector stations. We demonstrate with a combined analysis that the two methods give a consistent timing calibration with an accuracy of 2 ns or better. Consequently, the beacon method alone can be used in the future to continuously determine and correct for GPS clock drifts in each individual event measured by AERA.

Symbolic dynamics generated by a hybrid chaotic systems

We consider piecewise defined differential dynamical systems which can be analysed through symbolic dynamics and transition matrices. We have a continuous regime, where the time flow is characterized by an ordinary differential equation (ODE) which has explicit solutions, and the singular regime, where the time flow is characterized by an appropriate transformation. The symbolic codification is given through the association of a symbol for each distinct regular system and singular system. The transition matrices are then determined as linear approximations to the symbolic dynamics. We analyse the dependence on initial conditions, parameter variation and the occurrence of global strange attractors.

Flowering synchronization in hybrid rice parental lines.

The cultivation of hybrid rice is a technology that allows for an increase in grain yield of 30% relative to the grain yield of conventional cultivars. However, the main challenge for this technology is related to seed production, which has high production costs and low seed yields. Therefore, agronomic techniques that could enhance flowering synchrony of parental lines in the field are essential for an efficient production system of hybrid rice seeds. The objective of this work was to study the effects of sowing depth, plant density and fertilization with nitrogen or phosphorus as potential techniques to increase the pollen availability in the field and, consequently, the flowering synchrony between parental lines in the production of hybrid rice seeds. The experiments were conducted during two growing seasons in the Central Region of Brazil. All of the experiments were conducted as a randomized complete block in a split plot scheme; however, the experiment with P fertilization had a factorial design. Our research allow inferring that nitrogen fertilization technique applied to the soil or foliar at the time of panicle differentiation does not affect the time of onset of flowering of rice varieties INTA Puitá CL and L106R, which are potential R lines for the production of hybrid rice. Agronomic techniques of variation in sowing depth, seeding rate and the phosphate fertilization affect the time of onset of flowering from 10 to 19 degree-days, which could represent two days in the crop cycle, for the line L106R. Such techniques constitute potential alternatives for use in hybrid rice seed production systems and could be applied in alternated blocks of R lines in the field to obtain longer periods of pollen availability in the field.

Follicular wave synchronization on in vivo embryo production in Santa Ines sheep.

This study aimed to evaluate two hormonal protocols for synchronization of follicular wave emergence on in vivo embryo production in Santa Ines sheep under tropical conditions. The greater PRCL rate in GT probably contributed to the smaller number of viable embryos. Thus, it is suggested the appliance indicated the GEm protocol for in vivo embryo production in Santa Ines sheep under tropical conditions.

Chronic Telogen Effluvium And Female Pattern Hair Loss Are Separate And Distinct Forms Of Alopecia: A Histomorphometric And Immunohistochemical Analysis.

Chronic telogen effluvium (CTE), a poorly understood condition, can be confused with or may be a prodrome to female pattern hair loss (FPHL). The pathogenesis of both is related to follicle cycle shortening and possibly to blood supply changes. To analyze a number of histomorphometric and immunohistochemical findings through vascular endothelial growth factor (VEGF), Ki-67, and CD31 immunostaining in scalp biopsies of 20 patients with CTE, 17 patients with mild FPHL and 9 controls. Ki-67 index and VEGF optical density were analyzed at the follicular outer sheath using ImageJ software. CD31 microvessel density was assessed by a Chalkley grid. Significant follicle miniaturization and higher density of nonanagen follicles were found in FPHL, compared with patients with CTE and controls. Ki-67+ index correlated positively with FPHL histological features. The FPHL group showed the highest VEGF optical density, followed by the CTE and control groups. No differences were found in CD31 microvessel density between the three groups. Histomorphometric results establish CTE as a distinct disorder, separate from FPHL from its outset. Its pathogenic mechanisms are also distinct. These findings support the proposed mechanism of 'immediate telogen release' for CTE, leading to cycle synchronization. For FPHL, accelerated anagen follicular mitotic rates and, thus, higher Ki-67 and VEGF values, would leave less time for differentiation, resulting in hair miniaturization.

Sistema de sincronismo entre a colhedora de cana-de-açúcar e o veículo de transbordo

One of the problems found in mechanical harvest of sugar cane is the lack of synchronism between the harvest machine and the infield wagon, causing crop losses as well as operational capacity. The objective of the present research was to design a system capable of helping to synchronize the sugar cane harvest machine with the wagon. The communication between tractor and harvest machine is wireless. Two ultrasound sensors coupled to the elevator and a microprocessor manage such information, generating a correct synchronization among the machines. The system was tested in laboratory and on field performing its function adequately, maintaining the two machines in synchronization, indicating and alerting the operators their relative positions. The developed system reduced the sugar cane lost in 60 kg ha-1 comparing to the harvest with the system turned off.

Comparação entre protocolos de marcadores anatomicos e tecnicos para analise cinematica na marcha e na corrida

Universidade Estadual de Campinas . Faculdade de Educação Física

Metodologia para descrição tridimensional do movimento humano a partir de cameras de video não sincronizadas

Universidade Estadual de Campinas. Faculdade de Educação Física

Efeitos de dietas com níveis crescentes de milho no metabolismo ruminal de energia e proteína em bubalinos

Avaliaram-se os efeitos de dietas com níveis crescentes de milho em grão moído (0, 22, 37 e 49% na MS) em substituição ao feno de coast-cross mantendo-se diferentes relações proteína:carboidratos não-fibrosos (PB:CNF = 1,01; 0,39; 0,33 e 0,27) sobre o metabolismo ruminal de búfalos. Utilizaram-se quatro búfalos fistulados no rúmen, mantidos em delineamento quadrado latino 4 × 4, para a coleta de amostras do líquido ruminal, colhidas em cada período experimental (de 28 dias) nos tempos 0, 2, 4 e 8 horas após a alimentação. Em geral, os bubalinos apresentaram boa capacidade tamponante no rúmen, com pH médio alto (6,70) e aumento da ingestão de milho em grão moído. O acréscimo nos níveis de milho na dieta promoveu aumento da produção de ácido butírico. Somente a dieta com 49% de milho promoveu melhor fermentação ruminal, com menor propoção de ácidos acético:propiônico. A relação PB:CNF de 1,01 indica deficiência de energia da dieta disponível para microrganismos no rúmen ao longo do dia, enquanto dietas com PB:CNF entre 0,39 e 0,27 promovem fermentações ruminais semelhantes, o que indica sincronismo na utilização de nitrogênio e energia pelos microrganismos no rúmen nessas condições.

Influence of light and temperature on seed germination of Cereus pernambucensis Lemaire (Cactaceae)

The objective of the present study was to evaluate the effects of light and temperature on germination of Cereus pernambucensis seeds, a species of columnar cactus native to Brazil and naturally incident in the restinga. Cereus pernambucensis seeds were incubated under different temperatures, from 5 to 45 °C, with 5 °C intervals, and under alternating temperatures of 15-20 °C, 15-30 °C, 20-25 °C, 20-30 °C, 20-35 °C, 25-30 °C, 25-35 °C, and 30-35 °C, both under continuous white light and dark. The seeds were also incubated in a gradient of phytochrome photoequilibrium at 25 °C. The highest percentage germination in this species was between 25 and 30 °C. The minimum temperature was between 15 and 20 °C and the maximum between 35 and 40 °C. Alternating temperatures did not affect the percentage of seed germination, but it did alter the rate and synchronization indexes. Seeds incubated in the dark did not germinate under any of the conditions tested, indicating that this species when cultivated present light sensitive seeds controlled by phytochrome. The seeds can tolerate a lot of shade conditions, germinating under very low fluence response of phytochrome.

Morphological features and vascularization study of caprine cyclic corpus luteum

Corpus luteum is a temporary endocrine gland that regulates either the estrous cycle and pregnancy. It presents extreme dependency on the adequate blood supply. This work aims to evaluate goat corpus luteum (CL) vascular density (VD) over the estrous cycle. For that purpose, 20 females were submitted to estrus synchronization/ovulation treatment using a medroxyprogesterone intra-vaginal sponge as well as intramuscular (IM) application of cloprostenol and equine chorionic gonadotrophine (eCG). After sponge removal, estrus was identified at about 72hs. Once treatment was over, female goats were then subdivided into 4 groups (n=5 each) and slaughtered on days 2, 12, 16 and 22 after ovulation (p.o). Ovaries were collected, withdrawn and weighted. CL and ovaries had size and area recorded. Blood samples were collected and the plasma progesterone (P4) was measured through RIA commercial kits. The VD was 24.42±6.66, 36.26±5.61, 8.59±2.2 and 3.97±1.12 vessels/mm² for days 2, 12, 16 and 22 p.o, respectively. Progesterone plasma concentrations were 0.49±0.08, 2.63±0.66, 0.61±0.14 and 0.22±0.04ng/ml for days 2, 12, 16 e 22 p.o, respectively. Studied parameters were affected by the estrous cycle phase. Values greater than 12 p.o were observed. In the present work we observed that ovulation occurred predominantly in the right ovary (70% of the animals), which in turn presented bigger measures than the contra lateral one. There is a meaningful relationship between the weight and size of the ovary and these of CL (r=0.87, r=0.70, respectively, p<0.05). It is possible to conclude that morphology of goat's ovaries and plasma progesterone concentration changed according to estrous cycle stages. We propose these parameters can be used as indicators of CL functional activity.

Associação da medroxiprogesterona ao protocolo Ovsynch para inseminação artificial em tempo fixo de búfalas cíclicas (Bubalus bubalis) criadas na Amazônia Oriental

O presente estudo visou avaliar os efeitos da associação da medroxiprogesterona (análogo sintético da progesterona) ao protocolo Ovsynch sobre o crescimento folicular, a ovulação e a taxa de concepção de búfalas criadas na Amazônia Oriental (Tracuateua-PA). Vinte e sete fêmeas adultas (G1 n=14 e G2 n=13), cíclicas, sem bezerro ao pé e com ECC 3,5 foram submetidas a Ovsynch. Os animais do G2 receberam 60 mg de medroxiprogesterona entre D0 e D7 (D0=início do tratamento). A ultra-sonografia ovariana foi realizada nos D 0, 7, 9 e 10. O contingente de folículos pequenos diferiu no D7 (G1: 4,57±0,60 versus G2: 6,54±0,67; P=0,05). Tempo e tratamento influenciaram o diâmetro folicular no D7. O crescimento do folículo dominante entre D7 e D9 foi maior nos animais tratados (G1: 2,05±0,49 mm/dia versus 3,48±0,41 mm/dia; P<0,05). Mais animais do G1 ovularam precocemente (35,71% versus 30,77%), porém isso não afetou as taxas de concepção (G1: 50,00% e G2: 30,77%; P>0,05). Os achados sugerem que a medroxiprogesterona (1) aumenta recrutamento folicular e retarda o crescimento dos folículos com diâmetro maior que 5,0 mm entre D0 e D7; (2) sua retirada incrementa em 1,7 vezes o crescimento folicular do D7 ao D9; (3) pode contribuir para a ovulação de folículos maiores e, em tese, para maior formação de tecido luteínico; (4) não promove ovulação precoce após o Ovsynch; (5) não eleva as taxas de concepção após sincronização de fêmeas cíclicas e com bom escore corporal, devendo ser avaliada para uso em fêmeas acíclicas ou com ECC mais baixo.

An Extension of the Invariance Principle for a Class of Differential Equations with Finite Delay

An extension of the uniform invariance principle for ordinary differential equations with finite delay is developed. The uniform invariance principle allows the derivative of the auxiliary scalar function V to be positive in some bounded sets of the state space while the classical invariance principle assumes that. V <= 0. As a consequence, the uniform invariance principle can deal with a larger class of problems. The main difficulty to prove an invariance principle for functional differential equations is the fact that flows are defined on an infinite dimensional space and, in such spaces, bounded solutions may not be precompact. This difficulty is overcome by imposing the vector field taking bounded sets into bounded sets.

Anticipation of pain enhances the nociceptive transmission and functional connectivity within pain network in rats

Background: Expectation is a very potent pain modulator in both humans and animals. There is evidence that pain transmission neurons are modulated by expectation preceding painful stimuli. Nonetheless, few studies have examined the influence of pain expectation on the pain-related neuronal activity and the functional connectivity within the central nociceptive network. Results: This study used a tone-laser conditioning paradigm to establish the pain expectation in rats, and simultaneously recorded the anterior cingulate cortex (ACC), the medial dorsal thalamus (MD), and the primary somatosensory cortex (SI) to investigate the effect of pain expectation on laser-induced neuronal responses. Cross-correlation and partial directed coherence analysis were used to determine the functional interactions within and between the recorded areas during nociceptive transmission. The results showed that under anticipation condition, the neuronal activity to the auditory cue was significantly increased in the ACC area, whereas those to actual noxious stimuli were enhanced in all the recorded areas. Furthermore, neuronal correlations within and between these areas were significantly increased under conditions of expectation compared to those under non-expectation conditions, indicating an enhanced synchronization of neural activity within the pain network. In addition, information flow from the medial (ACC and MD) to the lateral (SI cortex) pain pathway increased, suggesting that the emotion-related neural circuits may modulate the neuronal activity in the somatosensory pathway during nociceptive transmission. Conclusion: These results demonstrate that the nociceptive processing in both medial and lateral pain systems is modulated by the expectation of pain.

Border figure detection using a phase oscillator network with dynamical coupling

Oscillator networks have been developed in order to perform specific tasks related to image processing. Here we analytically investigate the existence of synchronism in a pair of phase oscillators that are short-range dynamically coupled. Then, we use these analytical results to design a network able of detecting border of black-and-white figures. Each unit composing this network is a pair of such phase oscillators and is assigned to a pixel in the image. The couplings among the units forming the network are also dynamical. Border detection emerges from the network activity.