On the dynamics of bubbles in boiling water

We investigate the dynamics of many interacting bubbles in boiling water by using a laser scattering experiment. Specifically, we analyze the temporal variations of a laser intensity signal which passed through a sample of boiling water. Our empirical results indicate that the return interval distribution of the laser signal does not follow an exponential distribution; contrariwise, a heavy-tailed distribution has been found. Additionally, we compare the experimental results with those obtained from a minimalist phenomenological model, finding a good agreement.Comment: Accepted for publication in Chaos, Solitons & Fractal

Milk acidity, curd firming time, curd firmness and protein and fat losses in the Parmigiano- Reggiano cheesemaking

The cheese yield depends on the milk casein content and on the fat to casein ratio. The efficiency of the milk transformation depends on curd particles ("curd fines") that remain in the cooked whey and on the losses of fat and casein as it is

Information Diversity in Coherent MIMO Radars

In this paper, the concept of information diversity in both the space and frequency domains is investigated for multiple-input multiple-output (MIMO) radars with widely separated antennas. Compared to phased-antenna arrays and multistatic radars, they can exploit more degrees of freedom, allowing them to maximize the information content upon centralized data fusion, thus granting unprecedented target detection and localization capabilities.This analysis proceeds in parallel with the running progresses of microwave photonics (MWP), which could represent, in the near future, a new paradigm for the development of centralized MIMO radar architectures.Thus, understanding the implications of information diversity becomes essential to foretell the system effectiveness in detecting and resolving closely spaced targets, as well as in suppressing sidelobes which may lead to false alarms. Performance metrics are proposed and evaluated to characterize the effects that information diversity has on centralized MIMO radars with widely separated antennas. On the other hand, the proposed methodology could reveal precious for designing the optimum system configuration

Effects of milk storage temperature at the farm on the characteristics of Parmigiano Reggiano cheese: chemical composition and proteolysis.

Parmigiano Reggiano is a Protected Designation of Origin (PDO) cheese whose official production protocol provides that milk cannot be stored at less than 18 °C at the farm. The possibility of refrigerating milk at the farm is highly debated, since it should allow for the limiting of bacterial growth, thus improving the quality of the cheese. The present research aimed to study the influence of storing the milk at 9 °C on the chemical composition and proteolysis during the ripening of Parmigiano Reggiano cheese. The experimentation considered six cheese-making trials, in which both evening and morning milks were subdivided into two parts that were maintained at 9 and 20 °C. After Parmigiano Reggiano cheese-making, one of the twin wheels obtained was analyzed after 21 months of ripening. From each cheese, two different samples were taken, one from the inner zone, and the other from the outer zone. The results of the chemical analyses evidenced that milk storage at 9 °C significantly (p ≤ 0.05) influenced fat, crude protein, soluble nitrogen and peptone nitrogen contents. Nevertheless, the differences observed with respect to the cheese obtained with milk stored under standard condition were very small and should be considered within the “normal variations” of Parmigiano Reggiano chemical characteristics

The Contribution of the Smectic-Nematic Interface to the Surface Energy

The contribution of the smectic-nematic interface to the surface energy of a nematic liquid crystal sample is analyzed. By means of a simple model it is shown that the surface energy depends on the thickness of the region over which the transition smectic-nematic takes place. For perfectly flat substrates this thickness is of the order of the correlation length entering in the transition. An estimate of this contribution shows that it is greater than the one arising from the nematic-substrate interaction. Moreover, it is also shown that the surface energy determined in this way presents a non-monotonic behavior with the temperature.Comment: 10 pages, revte

Caracterização Bioquímica e Farmacológica da Sp-ctx -toxina Multifuncional da Peçonha do Peixe Escorpião scorpaena Plumieri

Citolisinas são produzidas por diversos organismos e apresentam atividade tóxica a células individuais, causando dissolução através de lise. Citolisinas de peçonhas de peixes são proteínas multifuncionais que apresentam efeitos neurotóxicos, cardiotóxicos e inflamatórios, sendo descritas como fatores proteicos letais. Uma citolisina hemolítica lábil, formadora de poro, denominada Sp-CTx Scorpaena plumieri - Cytolytic Toxin (glicoproteína, 2 subunidades de 65 kDa), foi recentemente purificada da peçonha do peixe escorpião Scorpaena plumieri. O objetivo deste trabalho foi estabelecer condições ótimas de manutenção da atividade hemolítica de Sp-CTx e dar continuidade à sua caracterização bioquímica e farmacológica. A estabilidade da Sp-CTx em diferentes condições (pH, temperatura e presença de cosolutos) e o efeito de diferentes cátions e lipídios de membrana sobre a atividade hemolítica foram avaliadas em eritrócitos de coelho. Foi demonstrado que a atividade hemolítica da Sp-CTx é mantida quando armazenada em 500 mM de NaCl, 1 M de sulfato de amônio, 60 mM de trealose e 10% de glicerol em pH 7,4 a 4 ºC e em glicerol 10% a -80 e -196 ºC. Também foi visto que a atividade hemolítica da Sp-CTx é dependente de cálcio e é completamente inibida por EDTA. O colesterol e o fosfatidilglicerol reduziram a hemólise induzida pela toxina, o que sugere que a toxina forma poro do tipo barril e é dependente da interação eletrostática com lipídios de membrana. Os motivos de carboidratos da Sp-CTx foram avaliados por western blot usando o kit DIG Glycan Differentiation sugerindo a presença dos motivos: galactose (1-4) N-acetilglucosamina e ácido siálico (2-3) galactose em complexos de N- e/ou O-glicanos. A resposta inflamatória induzida pela Sp-CTx foi avaliada usando como modelo o teste da pata de camundongo. Sp-CTx induziu nocicepção e resposta edematogênica local dose-dependente. O edema induzido foi significativamente reduzido pela administração prévia de HOE-140 e de aprotinina. Estes dados evidenciam o envolvimento do sistema calicreína cinina na resposta inflamatória induzida por Sp-CTx

Does the use of playback affect the estimated numbers of red–legged partridge Alectoris rufa?

¿Afecta el uso de playback a las cifras estimadas de perdiz roja, Alectoris rufa? La perdiz roja, Alectoris rufa, vive en una situación de riesgo potencial en cuanto a su conservación a largo plazo en Italia, dado que su hábitat se ve cada vez más amenazado por la desaparición de los ambientes tradicionalmente relacionados con la agricultura. En tal situación, es importante aplicar métodos de control efectivos para estudiar los cambios poblacionales a través del tiempo, y la identificación de amenazas potenciales a la conservación. El objetivo de este estudio era evaluar la efectividad del método de playback para estimar la densidad de machos que vocalizaban. Comparamos el método del playback con las llamadas espontáneas de los machos al amanecer, y las observaciones directas a lo largo de transectos. El resultado de los datos sin procesar de los recuentos mediante playback revelaron una gran tasa de subestimación, comparados con el método que rindió los mejores resultados: el recuento de vocalizaciones espontáneas al amanecer. Nuestro estudio proporciona una evaluación crítica de un método que está ampliamente extendido, aunque los datos sobre su eficacia son escasos. Nuestros datos no evalúan la probabilidad de detección de los tres métodos. Nuestra intención era únicamente evaluar qué métodos arrojan los mejores resultados en términos de la estimación del tamaño de la población en las mismas condiciones de campo (misma densidad de población, mismo periodo, misma área de monitorización). Los resultados arrojan algunas dudas sobre la capacidad del método del playback para monitorizar las poblaciones de perdiz roja. Se discuten las implicaciones de nuestros resultados para su aplicación en la gestión de poblaciones de perdiz roja.¿Afecta el uso de playback a las cifras estimadas de perdiz roja, Alectoris rufa? La perdiz roja, Alectoris rufa, vive en una situación de riesgo potencial en cuanto a su conservación a largo plazo en Italia, dado que su hábitat se ve cada vez más amenazado por la desaparición de los ambientes tradicionalmente relacionados con la agricultura. En tal situación, es importante aplicar métodos de control efectivos para estudiar los cambios poblacionales a través del tiempo, y la identificación de amenazas potenciales a la conservación. El objetivo de este estudio era evaluar la efectividad del método de playback para estimar la densidad de machos que vocalizaban. Comparamos el método del playback con las llamadas espontáneas de los machos al amanecer, y las observaciones directas a lo largo de transectos. El resultado de los datos sin procesar de los recuentos mediante playback revelaron una gran tasa de subestimación, comparados con el método que rindió los mejores resultados: el recuento de vocalizaciones espontáneas al amanecer. Nuestro estudio proporciona una evaluación crítica de un método que está ampliamente extendido, aunque los datos sobre su eficacia son escasos. Nuestros datos no evalúan la probabilidad de detección de los tres métodos. Nuestra intención era únicamente evaluar qué métodos arrojan los mejores resultados en términos de la estimación del tamaño de la población en las mismas condiciones de campo (misma densidad de población, mismo periodo, misma área de monitorización). Los resultados arrojan algunas dudas sobre la capacidad del método del playback para monitorizar las poblaciones de perdiz roja. Se discuten las implicaciones de nuestros resultados para su aplicación en la gestión de poblaciones de perdiz roja.The red–legged partridge Alectoris rufa lives in a situation of potential conservation risk for its long–term preservation in Italy as its habitat is increasingly threatened by the disappearance of traditional agriculture–related environments. In such a situation, it is important to use effective and appropriate monitoring methods to assess population changes over time and to identify potential conservation threats. The objective of this study was to evaluate the effectiveness of the playback method to estimate the density of calling males. We compared playback method with spontaneous calling of males at dawn and direct observations along transects. The results on raw count data of playback counts revealed a strong underestimation rate compared to the method that gave the best results: count of spontaneous calls at dawn. Our study provides a critical evaluation of a method that is widely used even though data about its effectiveness are scarce. Our data do not evaluate detection probability of the three methods. Our aim was only to evaluate which methods give the best results in term of population size estimation under the same field condition (same population density, same period, same monitoring area). The results raise some doubts about the ability of the playback method to monitor red–legged partridge populations. The implications of our results for red–legged population management are discussed

Influence of feeding flavouring-appetizing substances on activity of cows in an automatic milking system

Aim of this research was to study the effect of somatic cell count on mineral content and salt equilibria at the level of quarter milk samples. Ten Italian Friesian cows, in which two homologous quarters (front quarters in 1 cow, rear quarters in 6 cows and both rear and front quarters in 3 cows) were characterised by a milk SCC400,000 cells/mL (HC-milk), respectively, were selected. Cows were milked at quarter level during the morning milking and a single sample was collected from each selected quarter, thus, 26 quarter milk samples were collected. Compared to LC-milk, HC-milk was characterised by a lower content of phosphorus and potassium and by a higher content of both sodium and chloride. The equilibrium of calcium, phosphorus and magnesium between the colloidal and soluble phase of milk and the mineralisation degree of the casein micelles, were not different between HC and LC milk