The influence of frequency, volume, and viscosity on the ultrasonic atomization threshold of sessile droplets.

In this research, we present a study on the atomization threshold (ATh) of sessile droplets, analyzing its relationship with the excitation frequency fexc (55-48 kHz), droplet volume Vdrop (1-100 µl), and droplet viscosity µ (1-6 mPa⋅s). The investigation focused on the atomization thresholds using ultrasonic excitation of distilled water droplets and water- polyethylene glycol (PEG)-8000 mixtures deposited on vibrating surfaces. The obtained results are compared with previously reported theoretical models. A modification to the model proposed by Alzuaga et al. [Alzuaga, Manceau, and Bastien, J. Sound Vib. 282(1-2), 151-162 (2005)] is suggested to determine the atomization thresholds of sessile droplets, incorporating the atomization droplet size equation proposed by Rajan and Pandit and an empirical constant α to account for the effect of droplet volume in this process. The results show that the relationship between the atomization threshold and viscosity does not fit well with the prediction of Eisenmenger [Acta Acust united Acust. 9(4), 327-340 (1959)] and Pohlman and Stamm [Untersuchung Zum Mechanismus Der Ultraschallvernebelung an Flüssigkeitsoberflächen im Hinblick Auf Technische Anwendungen (Investigation on the Mechanism of Ultrasonic Nebulization on Liquid Surfaces Considering Technical Applications) (VS Verlag für Sozialwissenschaften, Wiesbaden, Germany, 1965)] and Pohlman et al. [Pohlman, Heisler, and Cichos, Ultrasonicc 12(1), 11-15 (1974)] (ATh∝µ). However, the data tendency aligns with the model proposed by Alzuaga (ATh ∝ µ1/2). The results obtained in this study provide a deeper understanding of the atomization thresholds of sessile droplets through ultrasonic excitation.

On the dynamics of a big drop in acoustic levitation.

The acoustic levitation of a drop is a complex process that needs a high-intensity non-linear acoustic field; the sound pressure level has to be sufficient to raise the drop but not too large to avoid its atomization, limiting the maximum size of a levitated drop. In this paper, we present an experimental study of big drops levitation with a volume up to 166±2µl and with an effective diameter 6.82±0.03mm, figures one magnitude order larger than the maximum drop volume reported in the literature. Our acoustic levitator produces an acoustic field with a different shape than the field produced by a typical levitator. Our measurements and simulations of the acoustic field and drop dynamics suggest that the levitation of big drops is possible because the distribution of radiation pressure over the drop surface in our system differs from that in a typical acoustic levitator; its maximum value appears on the top surface of the drop and not in its equator. In addition, we determined the upper and lower limits of sound pressure necessary for the levitation of drops of various sizes that allow our system.

Characterization of Current Fusarium oxysporum f. sp. vasinfectum Isolates from Cotton in the San Joaquin Valley of California and Lower Valley El Paso, Texas.

Fusarium oxysporum f. sp. vasinfectum race 4 is a causal agent of Fusarium wilt of cotton (Gossypium spp.). This study aimed to characterize the existing distribution and frequency of current field populations of F. oxysporum f. sp. vasinfectum race 4 genotypes in the San Joaquin Valley (SJV) of California and Lower Valley El Paso, TX and examine representative isolates for aggressiveness during different stages of seedling development. A survey was conducted from 2017 to 2019 across 13 locations in the SJV and one location in El Paso, TX during 2018. From the SJV, isolates identified as the F. oxysporum f. sp. vasinfectum race 4 T genotype were dispersed across the SJV, whereas isolates identified as the F. oxysporum f. sp. vasinfectum race 4 N genotype were most frequently isolated from cotton fields in the northern county of Merced. The F. oxysporum f. sp. vasinfectum race 4 isolates from the Texas location were identified as the MT genotype. A selection of representative isolates was evaluated using three inoculation assays (rolled-towel, F. oxysporum f. sp. vasinfectum-infested oat seed, and root-dip inoculation) to test the isolates' abilities to produce symptoms during seedling stages of cotton development. All isolates tested were capable of producing symptoms on cotton; however, isolate aggressiveness varied within and across inoculation assays. In all assays, higher levels of disease development were observed in the moderately susceptible Pima (Gossypium barbadense L.) cultivars (DP-340 or PHY-830) when compared with the moderately tolerant Upland (G. hirsutum L.) cultivar (FM-2334). However, no correlation was found among the different response variables for the rolled-towel assay when compared with the root-dip and infested oat seed assays. These results suggest that different genes are involved in the resistance response during the early seedling development stage measured in the rolled-towel assay compared with the later seedling development stages measured during the root-dip inoculation and infested oat seed assays, revealing the complexity of the Fusarium wilt disease and host-plant resistance mechanisms.

Use of afoxolaner for the treatment of lice (Goniodes pavonis) in different genera (Chrysolophus spp, Lophura spp, Phasianus spp, and Syrmaticus spp) and species of pheasants and West Mexican Chachalacas (Ortalis poliocephala).

Lice are ectoparasites capable of affecting birds, and can result in direct and indirect damage to their host. Afoxolaner is an isoxazoline that has been shown to be effective against these ectoparasites without known adverse effects. The objective of this research was to evaluate the effect of afoxolaner on lice in pheasants and plain chachalacas. A total of 29 pheasants of different genera and species (Chrysolophus pictus, C. amherstiae, Lophura swinghoii, L. nycthemera, Phasianus colchicus, and Syrmaticus reevesii) and 18 West Mexican Chachalacas (Ortalis poliocephala) naturally infested with Goniodes pavonis were used. The birds were allocated to one of two groups: group 1 treated with 2.50 mg/kg of afoxolaner, and group 2 given no treatment. Ectoparasites were collected using the adhesive tape technique and identified. Afoxolaner was administered later as a single dose to group 1, and the clinical assessment to detect ectoparasites was repeated 28 days post-treatment. On day 28 post-treatment, group 1 was found to be negative for the presence of lice. The body weights were compared at the beginning and end of the clinical assessment in both groups and a significant difference in weight of treated birds was found. The mean body weight decreased by 0.017 g in control group, whereas it increased by 0.016 g in treated group. Oral administration of afoxolaner is an effective option for the treatment of Goniodes pavonis infestations in zoo birds.

Effect of oral afoxolaner on naturally occurring infestations of peacocks by the louse Goniodes pavonis.

BACKGROUND: Ectoparasitism of ornamental birds, including captive species kept in zoos, represents a serious health problem. Up to 13 different species of lice have been reported to affect peacocks worldwide and heavy infestation may cause anaemia. Because of this, alternatives to the prevailing treatments have been sought including use of isoxazolines. This class of drugs has been used successfully in poultry without adverse effects on health or production. OBJECTIVE: To evaluate the effect of afoxolaner on the peacock louse (Goniodes pavonis). ANIMALS: Twenty-three peacocks (Pavo cristatus) with naturally occurring infestation with G. pavonis. METHODS AND MATERIALS: The peacocks were divided in two groups; one was treated once orally with 2.5 mg/kg afoxolaner and the other group received no treatment. Samples were collected using the acetate tape technique, for identification of lice by microscopy. Concomitantly, blood samples were taken to evaluate the haematocrit before and after the intervention. RESULTS: Treatment with afoxolaner significantly decreased the number of peacocks positive for lice (P = 0.02) compared to the control group, in which the number of positive birds did not decrease. The haematocrit improved in the afoxolaner-treated group from a baseline of 46.4%-54.7% at 35 days post-treatment, whereas it decreased in untreated birds (44.6%-40.7%). No adverse effects attributed to afoxolaner treatment were observed. CONCLUSIONS AND CLINICAL IMPORTANCE: Oral administration of afoxolaner is an effective treatment for G. pavonis infestation of peacocks.

Construyendo el TDAH con "sus" voces / Building aDHD with "their" voices

El TDAH es el trastorno neuropsicobiológico que con más frecuencia se diagnostica en la infancia. Sus síntomas principales: hiperactividad, impulsividad y déficit de atención, pueden afectar diversas esferas de la vida del paciente y de su entorno, convirtiéndose, así, en "expertos" en su enfermedad. El diagnóstico de TDAH no siempre es fácil. La aproximación terapéutica debe ser multimodal, desde un tratamiento centrado en trabajar sobre los problemas de conducta y aprendizaje hasta el tratamiento farmacológico. Su objetivo es ayudar al paciente y su familia a manejar los síntomas, aumentar el autocontrol, mejorar la socialización y gestionar la frustración. La técnica de investigación cualitativa denominada grupo de discusión resulta especialmente conveniente para recabar datos relativos a las opiniones, creencias, percepciones, intereses y actitudes de un grupo de personas implicadas en un determinado objeto de estudio. En este artículo describimos un caso práctico en los que se aplica el grupo de discusión para obtener información valiosa sobre el TDAH

ADHD is the psychoneurobiological disorder most often diagnosed in childhood. Its main symptoms: hyperactivity, impulsiveness and inattention, can affect various areas of the patient’s life and his/her environment, becoming thus "experts" in his/her illness. The diagnosis of ADHD is not always easy. Therapeutic approach should be multimodal, from a treatment focused on working on behavior and learning problems to drug treatment. Its aim is to help patient and family to manage symptoms, increase self-control, improve socialization and manage frustration. The qualitative research technique, known as focus or discussion group, is especially adequate for gathering information on the opinions, beliefs, perceptions, interests and attitudes of a group of individuals involved in a given object of study. In this article, we describe a practical case which has successfully applied focus groups for obtaining valuable data on AHDH

Salud mental: infancia, familia y cuidados / No disponible

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