Revisiting Citrus Rootstocks Polyploidy as a Means to Improve Drought Resilience: Sometimes Less Is More.

Polyploid varieties have been suggested as an alternative approach to promote drought tolerance in citrus crops. In this study, we compared the responses of diploid and tetraploid Sunki 'Tropical' rootstocks to water deficit when grafted onto 'Valencia' sweet orange trees and subjected to water withholding in isolation or competition experiments under potted conditions. Our results revealed that, when grown in isolation, tetraploid rootstocks took longer to show drought symptoms, but this advantage disappeared when grown in competition under the same soil moisture conditions. The differences in drought responses were mainly associated with variations in endogenous leaf levels of abscisic acid (ABA), hydrogen peroxide (H2O2) and carbohydrates among treatments. Overall, tetraploids were more affected by drought in individual experiments, showing higher H2O2 production, and in competition experiments, rapidly increasing ABA production to regulate stomatal closure and reduce water loss through transpiration. Therefore, our results highlight the crucial importance of evaluating diploid and tetraploid rootstocks under the same soil moisture conditions to better simulate field conditions, providing important insights to improve selection strategies for more resilient citrus rootstocks.

Extracellular vesicles derived from bovine adipose-derived mesenchymal stromal cells enhance in vitro embryo production from lesioned ovaries.

BACKGROUND AND AIMS: Ovum pick-up (OPU) is an intrinsic step of in vitro fertilization procedures. Nevertheless, it can cause ovarian lesions and compromise female fertility in bovines. Recently, we have shown that intraovarian injection of adipose-derived mesenchymal stromal cells (AD-MSCs) effectively preserves ovarian function in bovines. Given that MSC-derived extracellular vesicles (MSC-EVs) have been shown to recapitulate several therapeutic effects attributed to AD-MSCs and that they present logistic and regulatory advantages compared to AD-MSCs, we tested whether MSC-EVs would also be useful to treat OPU-induced lesions. METHODS: MSC-EVs were isolated from the secretome of bovine AD-MSCs, using ultrafiltration (UF) and ultracentrifugation methods. The MSC-EVs were characterized according to concentration and mean particle size, morphology, protein concentration and EV markers, miRNA, mRNA, long noncoding RNA profile, total RNA yield and potential for induction of the proliferation and migration of bovine ovarian stromal cells. We then investigated whether intraovarian injection of MSC-EVs obtained by UF would reduce the negative effects of acute OPU-induced ovarian lesions in bovines. To do so, 20 animals were divided into 4 experimental groups (n = 5), submitted to 4 OPU cycles and different experimental treatments including vehicle only (G1), MSC-EVs produced by 7.5 × 106 AD-MSCs (G2), MSC-EVs produced by 2.5 × 106 AD-MSCs (G3) or 3 doses of MSC-EVs produced by 2.5 × 106 AD-MSCs, injected after OPU sessions 1, 2 and 3 (G4). RESULTS: Characterization of the MSC-EVs revealed that the size of the particles was similar in the different isolation methods; however, the UF method generated a greater MSC-EV yield. MSC-EVs processed by both methods demonstrated a similar ability to promote cell migration and proliferation in ovarian stromal cells. Considering the higher yield and lower complexity of the UF method, UF-MSC-EVs were used in the in vivo experiment. We evaluated three therapeutic regimens for cows subjected to OPU, noting that the group treated with three MSC-EV injections (G4) maintained oocyte production and increased in vitro embryo production, compared to G1, which presented compromised embryo production following the OPU-induced lesions. CONCLUSIONS: MSC-EVs have beneficial effects both on the migration and proliferation of ovarian stromal cells and on the fertility of bovines with follicular puncture injury in vivo.

GABAergic Regulation of Astroglial Gliotransmission through Cx43 Hemichannels.

Gamma-Aminobutyric acid (GABA) is the primary inhibitory neurotransmitter in the brain. It is produced by interneurons and recycled by astrocytes. In neurons, GABA activates the influx of Cl- via the GABAA receptor or efflux or K+ via the GABAB receptor, inducing hyperpolarization and synaptic inhibition. In astrocytes, the activation of both GABAA and GABAB receptors induces an increase in intracellular Ca2+ and the release of glutamate and ATP. Connexin 43 (Cx43) hemichannels are among the main Ca2+-dependent cellular mechanisms for the astroglial release of glutamate and ATP. However, no study has evaluated the effect of GABA on astroglial Cx43 hemichannel activity and Cx43 hemichannel-mediated gliotransmission. Here we assessed the effects of GABA on Cx43 hemichannel activity in DI NCT1 rat astrocytes and hippocampal brain slices. We found that GABA induces a Ca2+-dependent increase in Cx43 hemichannel activity in astrocytes mediated by the GABAA receptor, as it was blunted by the GABAA receptor antagonist bicuculline but unaffected by GABAB receptor antagonist CGP55845. Moreover, GABA induced the Cx43 hemichannel-dependent release of glutamate and ATP, which was also prevented by bicuculline, but unaffected by CGP. Gliotransmission in response to GABA was also unaffected by pannexin 1 channel blockade. These results are discussed in terms of the possible role of astroglial Cx43 hemichannel-mediated glutamate and ATP release in regulating the excitatory/inhibitory balance in the brain and their possible contribution to psychiatric disorders.

Unprecedented multiphonon vibronic transitions of erbium ions on copper nanoparticle-containing tellurite glasses.

Erbium-doped tellurite glass containing copper nanoparticles showed multi-band emission of one particular transition (4I9/2→4I15/2, at 980 nm) due to electron-lattice coupling. The present study reports the vibronic transitions of intraconfigurational 4fn transitions of Er3+ ions in a tellurite host matrix at room temperature for the first time. The mechanisms of multiphoton transitions and the effect of laser heating are discussed here. This unprecedented behavior enables the design of a plethora of different applications spanning from tunable emission in the near infrared, such as lasers for bioimaging and biomedical fields, to energy conversion by thermophotovoltaic conversion of thermal radiation.

Mineralization of Sialoliths Investigated by Ex Vivo and In Vivo X-ray Computed Tomography.

The fraction of organic matter present affects the fragmentation behavior of sialoliths; thus, pretherapeutic information on the degree of mineralization is relevant for a correct selection of lithotripsy procedures. This work proposes a methodology for in vivo characterization of salivary calculi in the pretherapeutic context. Sialoliths were characterized in detail by X-ray computed microtomography (µCT) in combination with atomic emission spectroscopy, Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. Correlative analysis of the same specimens was performed by in vivo and ex vivo helical computed tomography (HCT) and ex vivo µCT. The mineral matter in the sialoliths consisted essentially of apatite (89 vol%) and whitlockite (11 vol%) with average density of 1.8 g/cm3. In hydrated conditions, the mineral mass prevailed with 53 ± 13 wt%, whereas the organic matter, with a density of 1.2 g/cm3, occupied 65 ± 10% of the sialoliths' volume. A quantitative relation between sialoliths mineral density and X-ray attenuation is proposed for both HCT and µCT.

Muscle Activation During Pilates Exercises in Participants With Chronic Nonspecific Low Back Pain: A Cross-Sectional Case-Control Study.

OBJECTIVE: To determine the amplitude of the electromyographic activity of trunk muscles during Pilates exercises in women with and without chronic low back pain (LBP). DESIGN: Case-control study. SETTING: University physical therapy clinic. PARTICIPANTS: Women (N=60) divided into an LBP group and a control group. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Amplitude of the electromyographic activity (root mean square values) of the gluteus maximus and external oblique muscles collected during 3 Pilates exercises: Shoulder Bridge performed on the mat, and Hip Roll and Breathing performed in equipment. Pain intensity was assessed in the LBP group. RESULTS: The amplitude of the electromyographic activity was similar between groups (P≥.05). For both groups, the amplitude of the gluteus maximus was higher in the Shoulder Bridge exercise compared with the Hip Roll with 2 springs (control group: mean difference [MD]=.18; 95% confidence interval [CI], .05-.41; LBP group: MD=.29; 95% CI, .16-.31) and the Breathing exercise (control group: MD=-.40; 95% CI, -.55 to -.26; LBP group: MD=-.36; 95% CI, -.52 to -.20). The amplitude of the external oblique muscle was higher in the Shoulder Bridge compared with the Hip Roll with 2 springs (control group: MD=.13; 95% CI, .05-.21; LBP group: MD=.18; 95% CI, .03-.33). Pain intensity increased after exercises, but this increase was lower for the mat exercises. CONCLUSIONS: Similar muscle activation between groups was found. The findings suggest that mat exercises caused less pain and a greater difference in the amplitude of muscle activation compared with the equipment-based exercises.

Local Response of Sialoliths to Lithotripsy: Cues on Fragmentation Outcome.

Lithotripsy methods show relatively low efficiency in the fragmentation of sialoliths compared with the success rates achieved in the destruction of renal calculi. However, the information available on the mechanical behavior of sialoliths is limited and their apparently tougher response is not fully understood. This work evaluates the hardness and Young's modulus of sialoliths at different scales and analyzes specific damage patterns induced in these calcified structures by ultrasonic vibrations, pneumoballistic impacts, shock waves, and laser ablation. A clear correlation between local mechanical properties and ultrastructure/chemistry has been established: sialoliths are composite materials consisting of hard and soft components of mineralized and organic nature, respectively. Ultrasonic and pneumoballistic reverberations damage preferentially highly mineralized regions, leaving relatively unaffected the surrounding organic matter. In contrast, shock waves leach the organic component and lead to erosion of the overall structure. Laser ablation destroys homogeneously the irradiated zones regardless of the mineralized/organic nature of the underlying ultrastructure; however, damage is less extensive than with mechanical methods. Overall, the present results show that composition and internal structure are key features behind sialoliths' comminution behavior and that the organic matter contributes to reduce the therapeutic efficiency of lithotripsy methods.

Impact of mass-screening on tuberculosis incidence in a prospective cohort of Brazilian prisoners.

BACKGROUND: Globally, prison inmates are a high-risk population for tuberculosis (TB), but the specific drivers of disease and impact of mass screening interventions are poorly understood. METHODS: We performed a prospective cohort study to characterize the incidence and risk factors for tuberculosis infection and disease in 12 Brazilian prisons, and to investigate the effect of mass screening on subsequent disease risk. After recruiting a stratified random sample of inmates, we administered a questionnaire to ascertain symptoms and potential risk factors for tuberculosis; performed tuberculin skin testing (TST); collected sera for HIV testing; and obtained two sputum samples for smear microscopy and culture, from participants reporting a cough of any duration. We repeated the questionnaire and all tests for inmates who remained incarcerated after 1 year. TST conversion was defined as TST ≥10 mm and an induration increase of at least 6 mm in an individual with a baseline TST <10 mm. Cox proportional hazard models were performed to identify risk factors associated with active TB. To evaluate the impact of screening on subsequent risk of disease, we compared TB notifications over one year among individuals randomized to screening for active TB with those not randomized to screening. RESULTS: Among 3,771 inmates recruited, 3,380 (89.6 %) were enrolled in the study, and 1,422 remained incarcerated after one year. Among 1,350 inmates (94.9 %) with paired TSTs at baseline and one-year follow-up, 25.7 % (272/1060) converted to positive. Among those incarcerated for the year, 10 (0.7 %) had TB at baseline and 25 (1.8 %) were diagnosed with TB over the subsequent year. Cases identified through active screening were less likely to be smear-positive than passively detected cases (10.0 % vs 50.9 %; p < 0.01), suggesting early case detection. However, there was no reduction in subsequent disease among individuals actively screened versus those not screened (1.3 % vs 1.7 %; p = 0.88). Drug use during the year (AHR 3.22; 95 % CI 1.05-9.89) and knows somebody with TB were (AHR 2.86; 95 % CI 1.01-8.10) associated with active TB during one year of follow up CONCLUSIONS: Mass screening in twelve Brazilian prisons did not reduce risk of subsequent disease in twelve Brazilian prisons, likely due to an extremely high force of infection. New approaches are needed to control TB in this high-transmission setting.

Active and latent tuberculosis in Brazilian correctional facilities: a cross-sectional study.

BACKGROUND: Tuberculosis (TB) rates among prisoners are more than 20 times that of the general population in Brazil, yet there are limited data available to facilitate the development of effective interventions in this high-transmission setting. We aimed to assess risk factors for TB infection and evaluate the yield of mass screening for active disease among inmates. METHODS: We administered a questionnaire and tuberculin skin test (TST) to a population-based sample of inmates from 12 prisons in Central-West Brazil and collected sera for HIV testing and two sputum samples for smear microscopy and culture from participants reporting a cough of any duration. Hierarchical Poisson regression models were used to evaluate factors associated with latent tuberculosis infection (LTBI). RESULTS: We recruited 3,380 inmates, of which 2,861 (84.6%) were males from 8 prisons, and 519 (15.4%) were females from 4 prisons. Among the 1,020 (30%) subjects who reported a cough, we obtained sputum from 691 (68%) and identified 31 cases of active TB for a point prevalence of 917 (95% CI, 623-1302) per 100,000 prisoners. Evaluation of the two sputum smear samples failed to identify 74% of the TB cases, and 29% of the cases reported less than 2 weeks of symptoms. Obtaining a second culture identified an additional 7 (24%) cases. The prevalences of LTBI were 22.5% and 11.7% for male and female prisoners, respectively and duration of incarceration (in years) was associated with LTBI in male and female in the multivariable model (1.04, 95% CI, 1.01-1.07 and 1.34, 95% CI, 1.06-1.70, respectively). The prevalence of LTBI is 8.6% among newly incarcerated inmates, among whom LTBI prevalence significantly increased by 5% with each year of incarceration. CONCLUSIONS: Although the overall LTBI prevalence among inmates in Central-West Brazil is low, tuberculosis incidence is high (>1,800/100,00), likely due to the high force of infection among a largely susceptible inmate population. Efforts to reduce transmission in prisons may require mass screening for active TB, utilizing sputum culture in case-detection protocols.

Determining Cut-Off Points for the Dental Fear Survey.

OBJECTIVE: To determine a high fear cut-off point score for the Dental Fear Survey (DFS) using a single-item self-report questionnaire. METHODS: The DFS, a 20-item questionnaire assessing fear of dental treatment, was completed by 1,256 participants with a mean age of 22.3 years (SD = 5.1). Another self-report questionnaire was used to collect data on previous dental experiences. A high fear cut-off point score was determined by calculating the receiver operating characteristic (ROC) curve for the DFS. Descriptive statistics and multinomial logistic regression were calculated; a significance level of p < 0.05 was used for all tests. RESULTS: The ROC curve indicated that a DFS score ≥ 53 corresponds to a sensitivity of 88.9% and a specificity of 92.5%. Most participants (n = 895; 71.5%) reported no fear of going to the dentist. There was significant association between DFS score and fear assessed with the question "Are you fearful of going to the dentist?" (p < 0.001). CONCLUSION: A cut-off point of 53 on the DFS total score represents the best compromise between sensitivity and specificity and can be used to predict high dental fear.

Dental Fear Survey: a cross-sectional study evaluating the psychometric properties of the Brazilian Portuguese version.

OBJECTIVE: The aim of this study was to evaluate the psychometric properties of the Brazilian version of the Dental Fear Survey (DFS), previously translated to the Brazilian Portuguese language and validated. METHODS: A cross-sectional study with 1,256 undergraduates from the city of Belo Horizonte, Brazil, was carried out. The DFS and a questionnaire about previous dental experiences were self-administered. Data analysis involved descriptive statistics, principal components analysis (PCA), confirmatory factor analysis (CFA), internal consistency and test-retest reliability, and construct, discriminant, and convergent validity. RESULTS: PCA identified a three-factor structure. CFA confirmed the multidimensionality of the Brazilian version of the DFS. A modified model of the Brazilian version of the DFS fits better than the hypothesized model. The Cronbach's alpha coefficient for the total DFS scale was 0.95. CONCLUSION: The DFS demonstrated acceptable construct validity, convergent validity, and discriminant validity. These results supported the reliability and validity of the DFS among Brazilian undergraduates.

Volatile compounds in citrus in adaptation to water deficit and to herbivory by Diaphorina citri: How the secondary metabolism of the plant is modulated under concurrent stresses. A review.

Citrus plants are grown in diverse regions of the world, from subtropical to semi-arid and humid tropical areas. Through mechanisms essential for their survival, they adapt to the environmental conditions to which they are subjected. Although there is vast literature on adaptation of citrus plants to individual stresses, plant responses to interaction among different types of stresses have not been clearly examined. Abiotic or biotic stresses, or a combination of these stresses, result in reorganization of plant energy resources for defense, whether it be for resistance, tolerance, or prevention of stress. Plants generally respond to these stress factors through production of secondary metabolites, such as volatile compounds, derived from different biosynthesis and degradation pathways, which are released through distinct routes. Volatile compounds vary among plant species, meeting the specific needs of the plant. Simultaneous exposure to the stress factors of water deficit and herbivory leads to responses such as qualitative and quantitative changes in the emission of secondary metabolites, and compounds may accumulate within the leaves or predispose the plant to more quickly respond to the stress brought about by the herbivore. The genetic makeup of citrus plants can contribute to a better response to stress factors; however, studies on the emission of volatile compounds in different citrus genotypes under simultaneous stresses are limited. This review examines the effects of abiotic stress due to water deficit and biotic stress due to herbivory by Diaphorina citri in citrus plants and examines their connection with volatile compounds. A summary is made of advances in knowledge regarding the performance of volatile compounds in plant defense against both stress factors, as well as the interaction between them and possible findings in citrus plants. In addition, throughout this review, we focus on how genetic variation of the citrus species is correlated with production of volatile compounds to improve stress tolerance.

Exploiting DNA methylation in cassava under water deficit for crop improvement.

DNA methylation plays a key role in the development and plant responses to biotic and abiotic stresses. This work aimed to evaluate the DNA methylation in contrasting cassava genotypes for water deficit tolerance. The varieties BRS Formosa (bitter) and BRS Dourada (sweet) were grown under greenhouse conditions for 50 days, and afterwards, irrigation was suspended. The stressed (water deficit) and non-stressed plants (negative control) consisted the treatments with five plants per variety. The DNA samples of each variety and treatment provided 12 MethylRAD-Seq libraries (two cassava varieties, two treatments, and three replicates). The sequenced data revealed methylated sites covering 18 to 21% of the Manihot esculenta Crantz genome, depending on the variety and the treatment. The CCGG methylated sites mapped mostly in intergenic regions, exons, and introns, while the CCNGG sites mapped mostly intergenic, upstream, introns, and exons regions. In both cases, methylated sites in UTRs were less detected. The differentially methylated sites analysis indicated distinct methylation profiles since only 12% of the sites (CCGG and CCNGG) were methylated in both varieties. Enriched gene ontology terms highlighted the immediate response of the bitter variety to stress, while the sweet variety appears to suffer more potential stress-damages. The predicted protein-protein interaction networks reinforced such profiles. Additionally, the genomes of the BRS varieties uncovered SNPs/INDELs events covering genes stood out by the interactomes. Our data can be useful in deciphering the roles of DNA methylation in cassava drought-tolerance responses and adaptation to abiotic stresses.

Effectiveness of mat Pilates or equipment-based Pilates in patients with chronic non-specific low back pain: a protocol of a randomised controlled trial.

BACKGROUND: Chronic low back pain is an expensive and difficult condition to treat. One of the interventions widely used by physiotherapists in the treatment of chronic non-specific low back pain is exercise therapy based upon the Pilates principles. Pilates exercises can be performed with or without specific equipment. These two types of Pilates exercises have never been compared on a high-quality randomised controlled trial. METHODS/DESIGN: This randomised controlled trial with a blinded assessor will evaluate eighty six patients of both genders with chronic low back pain, aged between 18 and 60 years, from one Brazilian private physiotherapy clinic. The patients will be randomly allocated into two groups: Mat Group will perform the exercises on the ground while the Equipment-based Group will perform the Pilates method exercises on the following equipment: Cadillac, Reformer, Ladder Barrel, and Step Chair. The general and specific disability of the patient, kinesiophobia, pain intensity and global perceived effect will be evaluated by a blinded assessor before randomisation and at six weeks and six months after randomisation. In addition, the expectation of the participants and their confidence with the treatment will be evaluated before randomisation and after the first treatment session, respectively. DISCUSSION: This will be the first study aiming to compare the effectiveness of Mat and Equipment-based Pilates exercises in patients with chronic non-specific low back pain. The results may help health-care professionals in clinical decision-making and could potentially reduce the treatment costs of this condition. TRIAL REGISTRATION: Brazilian Registry of Clinical Trials RBR-7tyg5j.

Susceptibility of limestone petrographic features to salt weathering: a scanning electron microscopy study.

Salt weathering is a major erosive process affecting porous materials in buildings. There have been attempts to relate erosive mass loss to physical characteristics of materials, but in the case of natural stone it is necessary to consider the effect of petrographic features that are a source of heterogeneity. In this paper, we use scanning electron microscopy before and after salt weathering tests in cubic specimens of three limestone types (two grainstones and a travertine) in an attempt to built conceptual models that relate petrographic features and salt weathering susceptibility (represented by mass loss). In the grainstones, the most relevant feature in controlling salt weathering processes is the interface between micrite aggregates and sparry cement that constitute weakness surfaces and barriers to fluid migration. Given the small size of the heterogeneities in relation to the test sample dimension and their spatial distribution, the macroscopic erosive patterns are globally homogeneously distributed, affecting edges and corners. In the travertine specimens, there are macroheterogeneities related to the presence of detritic-rich portions that cause heterogeneous erosive patterns in the specimens. Petrological modeling helps to understand results of salt weathering tests, supporting field studies for natural stone selection.

Structure and growth of sialoliths: computed microtomography and electron microscopy investigation of 30 specimens.

Theories have been put forward on the etiology of sialoliths; however, a comprehensive understanding of their growth mechanisms is lacking. In an attempt to fill this gap, the current study has evaluated the internal architecture and growth patterns of a set of 30 independent specimens of sialoliths characterized at different scales by computed microtomography and electron microscopy. Tomography reconstructions showed cores in most of the sialoliths. The cores were surrounded by concentric or irregular patterns with variable degrees of mineralization. Regardless of the patterns, at finer scales the sialoliths consisted of banded and globular structures. The distribution of precipitates in the banded structures is compatible with a Liesegang-Ostwald phenomenon. On the other hand, the globular structures appear to arise from surface tension effects and to develop self-similar features as a result of a viscous fingering process. Electron diffraction patterns demonstrated that Ca- and P-based electrolytes crystallize in a structure close to that of hydroxyapatite. The organic matter contained sulfur with apparent origin from sulfated components of secretory material. These results cast new light on the mechanisms involved in the formation of sialoliths.

X-ray microtomography applied to mortars: Review of microstructural visualization and parameterization.

The objective of the present work is to review the main applications of X-ray microtomography in the microstructural study of mortars, based on a literature search related to the subject, and to enable the development of more innovative and sustainable mortar formulations. This three-dimensional non-destructive microscopy allows qualitative visualization down to micrometric scales, visualization of the spatial distribution of the interior of samples of objects relatively opaque to visible light and the measurement of quantitative microstructural parameters. Furthermore, the combination of X-ray microtomography with other microstructural and compositional techniques can result in data at different scales of observation. Particularly, in the study of mortars, there are benefits in using this technique to better characterize materials in terms of the spatial structure of pores and other voids, aiding in the formulation of new mortars and in the characterization of mortar behavior, for example, after leaching and carbonation processes. This paper intends to contribute to the discussion of the potentials and drawbacks of this advanced technique, allowing a better characterization of mortars and enabling the development of more innovative and sustainable formulations.

Evaluation of the effects of the recommended oral dose of diflubenzuron on bovine sperm and oocyte quality using CASA and OPU-IVEP.

Introduction: The aim of this study was to evaluate potential effects of diflubenzuron on the production and quality of gametes, and on in vitro embryo production (IVEP) outcomes, in cattle. Methods: Two experiments were performed, the first to evaluate effects on semen, and the second on cumulus-oocyte complexes (COC) and on IVEP. Nelore (Bos taurus indicus) bulls (n = 14) or heifers (n = 16) were allocated into control (CG) or treatment (DIF) groups. All groups received a mineral mix supplement added (DIF) or not (CG) with diflubenzuron (30 mg/head/day), during 8 weeks. Animals were weighed and blood samples were collected throughout the experimental period. Every other week, bulls were subjected to semen collection and heifers to transvaginal ultrasound-guided follicle aspiration sessions. Semen underwent physical and morphological evaluation, and samples were stored for further computer-assisted sperm analysis. The COC recovered were evaluated according to morphology and those classified as viable were sent to an IVEP laboratory. Results: Diflubenzuron had no effect (P > 0.05) on average body weight or in any blood hematological or biochemical endpoints, regardless of gender. In experiment 1, there was no difference (P > 0.05) between DIF and CG groups for sperm concentration, morphology, or kinetics. In experiment 2, there was also no effect of diflubenzuron on the number of total, viable, or grade I oocytes, as well as on cleavage or blastocyst rates (P > 0.05). Discussion: In summary, the oral administration of diflubenzuron, within the recommended dose, has no short-term negative effects on sperm production and quality or on oocyte yield and developmental potential in vitro, in cattle.

Microstructural analysis of Iberian expanded clay aggregates.

This article presents a detailed study of the microstructure of Iberian expanded clay lightweight aggregates (LWA). Other than more commonly used mercury porosimetry (MP) and water absorption methods, the experimental study involves optical microscopy, scanning electron microscopy (SEM), and microtomography (µ-CT). Pore connectivity and how it is deployed are shown to some degree, and the pore size spectrum is estimated. LWA are in general characterized by a dense outer shell up to 200 µm thick, encasing an inner cellular structure of 10-100 times bigger pore size. Aggregate pore sizes may span from some hundreds of nanometers up to over 1 mm, though the range of 1-25 µm is more typical. A noteworthy fraction of these pores is closed, and they are mainly up to 1 µm. It is also shown that macropore spatial arrangement is affected by the manufacturing process. A step forward is given to understanding how the outer shell and the inner pore network influence the mechanical and physical LWA properties, particularly the density and water absorption. The joint consideration of µ-CT and SEM seems to be the most appropriate methodology to study LWA microstructure. MP analysis is likely to distort LWA pore spectrum assessment.

Drought tolerance memory transmission by citrus buds.

Plants face recurrent drought events, and previous stresses can influence their responses to subsequent stress episodes. Studies on drought stress memory are recent in citriculture, although they show promise as a tool for crop improvement. Here, we investigated whether stress memory mechanisms can be detected in citrus plants grafted with buds from plants subjected to recurrent water deficit. Three rootstock varieties, namely 'Rangpur Santa Cruz' lime, 'Sunki Maravilha' mandarin and 'Sunki Tropical' mandarin, in combination with 'Valencia' orange, were either maintained under full irrigation or subjected to one, two, or three water deficit cycles. Buds from 'Valencia' orange were grafted onto 'Swingle' citrumelo rootstocks and were evaluated. This combination displayed improved physiological and biochemical performance under water limitation, especially 'Valencia' buds grafted onto 'Sunki Maravilha', with better photosynthetic performance under water deficit. These findings indicate that genotype-dependent epigenetic memory is a key factor in restoring citrus plants' capacity to rely on previous stress experiences to restore better photosynthetic and physiological responses when undergoing new water deficit events. Therefore, epigenetic marks can be stored and transmitted to new citrus plants and are a promising alternative to enable increased water deficit tolerance when plants are then challenged by drought-prone environments.