Effect of pH on rheotaxis of bull sperm using microfluidics

The aim of the present research is to study the effect of pH values on the sperm rheotaxis properties. Semen collected from bulls was diluted with SOF medium (1:10). pH of the medium was adjusted using a digital pH meter to the following pH values: 6.0, 6.2, 6.4, 6.4, 6.8, 7.0. All kinetic parameters of sperm (n = 3,385) were determined through a computer‐assisted sperm analysis (CASA) system using microfluidic devices with controlled flow velocity. The following parameters were determined: total motility (TM%), positive rheotaxis (PR%), straightline velocity (VSL, μm/s), average path velocity (VAP, μm/s), linearity (LIN, as VSL/VCL, %), beat cross‐frequency (BCF, Hz) and curvilinear velocity (VCL, μm/s). Nitric oxide, calcium and potassium were estimated in semen at different pH values. To confirm the effect of nitric oxide and K⁺, we used sodium nitroprusside (an NO donor) and KCL as (a K⁺ donor) to see their effect on sperm PR%. The results showed no difference in TM% at pH (6–7). The PR% was the lowest at pH 6 and 7. The best parameters for the PR% were at pH 6.4–6.6. The concentration of Ca⁺² did not change at different pH values. The mean NO values decreased with the increase of pH; however, the mean values of K⁺ increased with the increase of pH. Addition of high concentration of NO and K⁺ to the semen media at fixed pH level had a negative effect on TM% and PR%. In conclusion, the bull sperm had the best rheotaxis properties at pH 6.4–6.6 and sensitive to the change of seminal NO and K⁺.     

Changes in Hydrocarbon Composition and Autochthonous Microorganism Growth of Contaminated Mining Soil During Bioremediation

The goal of this study was to evaluate the effect of high Tween 80 concentrations on hydrocarbon contaminants and hydrocarbonoclastic microorganisms present in contaminated mining soil during a bioremediation process. The independent variables included Tween 80 concentration and process time. The elected response variables included concentration of total petroleum hydrocarbons (TPH), the chemical composition of contaminants, viable microbial count, and CO₂ production. These were measured at various time points during the bioremediation process, which was conducted at room temperature. Higher removal of pollutants occurred at low Tween 80 concentrations. An analysis of the normalized variables shows that the rate of TPH degradation depended on microbial growth rate, which depended on Tween 80 concentration. The addition of Tween 80 changed the concentration and type of the residual hydrocarbon contaminants present, as well as the count and genus of the hydrocarbonoclastic microorganisms that grew during the bioremediation process. Higher concentrations of Tween 80 increased the levels of the chemical compounds present in the bioremediated soil while reducing the viable count and microbial diversity during the bioremediation process. Conversely, low Tween 80 concentrations produced only monoethylhexyl phthalate, which is not a petroleum hydrocarbon derivative. Overall, these results prove that the removal of TPH is dependent on the count and genus of active indigenous hydrocarbonoclastic microorganisms in soil, and these conditions may be controlled by modulating the concentration of Tween 80 that is applied.     

Effects of dietary microencapsulated <Emphasis Type="Italic">Cymbopogon flexuosus</Emphasis> essential oil on reproductive-related parameters in male <Emphasis Type="Italic">Rhamdia quelen</Emphasis>

In aquaculture, nutrition and supplemented diets have been shown to affect broodstock reproductive performance. In this study, we investigated the effects of dietary supplementation with Cymbopogon flexuosus essential oil (CFEO) microcapsules on reproductive-related parameters in silver catfish (Rhamdia quelen) male broodfish. Adult male broodstocks were separated into three groups according to the concentrations of supplemented CFEO (0.0?=?control; 1.0 or 3.0 mL per kg of diet). After 20 days under experimental conditions, the animals were euthanized and the gonads were harvested for gonadosomatic index, sperm analysis, oxidative stress, and histopathology; testosterone levels were measured in the plasma; gene expression of prl, smtl, pomca, and pomcb was assessed in the pituitary gland by real-time PCR. The results showed no alterations on reproductive parameters in R. quelen males treated with Cymbopogon flexuosus essential oil compared to the control-diet animals. In conclusion, CFEO microcapsules supplied for 20 days in the concentrations of 1.00 or 3.00 mL per kilogram of diet did not affect the reproduction criteria evaluated in this study in male silver catfish.     

<Emphasis Type="Italic">Aloysia triphylla</Emphasis> in the zebrafish food: effects on physiology,behavior, and growth performance

Dietary supplements are commonly used by animals and humans and play key roles in diverse systems, such as the immune and reproductive systems, and in metabolism. Essential oils (EOs), which are natural substances, have potential for use in food supplementation; however, their effects on organisms remain to be elucidated. Here, we examine the effects of dietary Aloysia triphylla EO supplementation on zebrafish behavior, metabolism, stress response, and growth performance. We show that fish fed diets containing A. triphylla EO presented an anxiolytic response, with reduced exploratory activity and oxygen consumption; no changes were observed in neuroendocrine stress axis functioning and growth was not impaired. Taken together, these results suggest that the A. triphylla EO supplementation is a strong candidate for use in feed, since it ensures fish welfare (anxiolytic behavior) with decreased oxygen consumption. This makes it suitable for use in high-density production systems without causing damage to the neuroendocrine stress axis and without growth performance being impaired.     

Effect of Pseudomonas putida and inorganic fertilizer on growth and productivity of habanero pepper (Capsicum Chinense Jacq.) in greenhouse

The habanero pepper is widely used in a variety of commercial food products. The increase in the cultivation area of the habanero pepper has increased the use of agricultural inputs, mainly inorganic fertilizers, which have high economic costs and cause negative effects to the soil and water. In recent years, the use of beneficial soil microorganisms has been studied as an alternative to inorganic fertilizers. In the present study, the effect of three strains of Pseudomonas putida on the growth and productivity of King Pakal hybrid habanero pepper with limited inorganic fertilizer in a greenhouse. It was found that a reduction of inorganic fertilizer application of 25% with P. putida rhizobacteria strains increased or maintained growth and productivity of King Pakal hybrid habanero pepper. Before these rhizobacteria can be used in the field, results will first need to be confirmed under more natural conditions.     

Rapid fluctuations in sea level recorded at huon peninsula during the penultimate deglaciation

About 140,000 years ago, the breakup of large continental ice sheets initiated the Last Interglacial period. Sea level rose and peaked around 135,000 years ago about 14 meters below present levels. A record of Last Interglacial sea levels between 116,000 years to 136, 000 years ago is preserved at reef VII of the uplifted coral terraces of Huon Peninsula in Papua New Guinea. However, corals from a cave situated about 90 meters below the crest of reef VII are 130, 000 +/- 2000 years old and appear to have grown in conditions that were 6 degreesC cooler than those at present. These observations imply a drop in sea level of 60 to 80 meters. After 130,000 years, sea level began rising again in response to the major insolation maximum at 126,000 to 128,000 years ago. The early (about 140,000 years ago) start of the penultimate deglaciation, well before the peak in insolation, is consistent with the Devils Hole chronology.     

Coral record of equatorial sea-surface temperatures during the penultimate deglaciation at huon peninsula

Uplifted coral terraces at Huon Peninsula, Papua New Guinea, preserve a record of sea level, sea-surface temperature, and salinity from the penultimate deglaciation. Remnants have been found of a shallow-water reef that formed during a pause, similar to the Younger Dryas, in the penultimate deglaciation at 130,000 +/- 2000 years ago, when sea level was 60 to 80 meters lower than it is today. Porites coral, which grew during this period, has oxygen isotopic values and strontium/calcium ratios that indicate that sea-surface temperatures were much cooler (22 degrees +/- 2 degreesC) than either Last Interglacial or present-day tropical temperatures (29 degrees +/- 1 degreesC). These observations provide further evidence for a major cooling of the equatorial western Pacific followed by an extremely rapid rise in sea level during the latter stages of Termination II.     

Effects of Water pH and Hardness on Infection of Silver Catfish,Rhamdia quelen,Fingerlings by Ichthyophthirius multifiliis

The aim of this study is to determine the effect of (1) different pH levels (5, 6, 7, 8, and 9) with water hardness 20 mg/L CaCO₃ and (2) pH 5 and 7 with varying water hardnesses (20, 60, and 120 mg/L CaCO₃) on the intensity of infection by Ichthyophthirius multifiliis in fingerlings of the silver catfish, Rhamdia quelen. In Experiment 1, the lowest and highest mortality rates were observed in fingerlings exposed to pH 5 and 9, respectively; in Experiment 2, fish kept at pH 5 and 7 with hardness 20 mg/L CaCO₃ showed significantly lowest and highest cumulative mortality, respectively, than those maintained in other conditions. The lowest intensity of trophonts/fingerling was observed at pH 5 and hardness 20 mg/L CaCO₃ in both experiments. We conclude that infection by I. multifiliis is less severe in silver catfish maintained at pH 5 and hardness 20 mg/L CaCO₃. High water hardness led to an increased intensity of trophonts and decreased survival in silver catfish kept at pH 5, but decreased intensity of trophonts and improved survival when the fish were kept at pH 7.     

Trajectory and cluster resilience elements: The case of the Brazilian wine cluster of the Serra Gaúcha

The recent economic, technological, and social shocks have led to a period of high economic uncertainty. The term “economic resilience” has been used to describe how regional clusters deal with and adapt to various shocks. This paper aims to analyze the elements that influence the resilience trajectory of a cluster. We conduct qualitative and exploratory research on the centennial Wine Cluster in Serra Gaúcha, Brazil, using data sources, interviews, and documents. To this end, we first identify seven elements that influence cluster resilience from the literature review. Subsequently, through an empirical case study, we verify whether these elements could represent the resilience of clusters. The results show that these seven elements are integrable and represent dimensions that explain the resilience of the cluster analyzed. Moreover, the findings highlight that resilience and resistance to crises are the historical results of improvements and the development of new routines for clustered companies. This study contributes to the cluster resilience literature and presents elements explaining how regions can adapt to and deal with shocks.