Behavior of Aedes albifasciatus (Diptera: Culicidae) larvae from eggs with different dormancy times and its relationship with parasitism by Strelkovimermis spiculatus (Nematoda: Mermithidae).

Aedine mosquitoes go through unfavorable periods as dormant eggs. However, extended dormancy times lead to a depletion of egg reserves, which might be partially compensated by changes in larval-feeding behavior. Changes in larval behavior may also be induced by parasitism by mermithids probably as a strategy to reduce the impact of the parasite on the host. The most abundant floodwater mosquito in southern South America is Aedes albifasciatus (Diptera: Culicidae), a species naturally parasitized by Strelkovimermis spiculatus (Nematoda: Mermithidae). This study aimed to evaluate the behavior of fourth-instar larvae of Ae. albifasciatus from eggs with 2, 4, and 6 months of dormancy, parasitized or not by S. spiculatus. To achieve this, eight categories of behavior were defined, and then, each individual was observed for 5 min, and its behaviors and their duration were recorded. The behaviors with the highest percentage of observation time were still (50.1%) and wriggle swimming (33.6%), while those with the lowest percentage of observation time were those involving active foraging (less than 8%). A great variability in the behaviors was observed among individuals within the same treatment. The type and duration of each behavior did not vary in relation to egg dormancy time or parasitism, but parasitism affected the level of larval activity. Parasitized larvae performed, on average, fewer behaviors than non-parasitized larvae. This result supports the hypothesis that S. spiculatus parasitism affects the behavior of Ae. albifasciatus larvae by reducing their level of activity.

Trichosporon asahii and Trichosporon inkin Biofilms Produce Antifungal-Tolerant Persister Cells.

Persister cells are metabolically inactive dormant cells that lie within microbial biofilms. They are phenotypic variants highly tolerant to antimicrobials and, therefore, associated with recalcitrant infections. In the present study, we investigated if Trichosporon asahii and T. inkin are able to produce persister cells. Trichosporon spp. are ubiquitous fungi, commonly found as commensals of the human skin and gut microbiota, and have been increasingly reported as agents of fungemia in immunocompromised patients. Biofilms derived from clinical strains of T asahii (n=5) and T. inkin (n=7) were formed in flat-bottomed microtiter plates and incubated at 35°C for 48 h, treated with 100 µg/ml amphotericin B (AMB) and incubated at 35°C for additional 24 h. Biofilms were scraped from the wells and persister cells were assayed for susceptibility to AMB. Additionally, we investigated if these persister cells were able to generate new biofilms and studied their ultrastructure and AMB susceptibility. Persister cells were detected in both T asahii and T. inkin biofilms and showed tolerance to high doses of AMB (up to 256 times higher than the minimum inhibitory concentration). Persister cells were able to generate biofilms, however they presented reduced biomass and metabolic activity, and reduced tolerance to AMB, in comparison to biofilm growth control. The present study describes the occurrence of persister cells in Trichosporon spp. and suggests their role in the reduced AMB susceptibility of T. asahii and T. inkin biofilms.

Resting egg banks can facilitate recovery of zooplankton communities after short exposure to glyphosate.

We assessed the short-term viability and recovery of zooplankton communities after exposure to glyphosate (active ingredient-a.i.). We conducted a hatching experiment in two steps: Step 1-natural lake sediments containing resting egg banks were placed into individual trays and exposed to a solution medium of glyphosate at three different treatments (LD = Values below the detection limits, LD < 0.05, 0.44, and 0.89 mg a.i./L) for 14 days; and Step 2-we replaced the exposure solution of glyphosate with distilled freshwater, keeping them all trays under freshwater conditions for another 14 day. The results from Step 1 showed significant effects of glyphosate on the emergence patterns of resting eggs, with a reduction in hatching of rotifers, mainly at concentrations of 0.44 and 0.89 mg a.i./L. On the other hand, the results from Step 2 showed an increase in the emergence of viable eggs for rotifers after restoration of freshwater conditions in all treatments; there was no effect for total zooplankton and microcrustaceans. These findings suggest that (i) glyphosate may, effectively, impair zooplankton hatching from resting egg banks; (ii) the magnitude of the negative effects depends on the the zooplanktonic group considered; and (iii) the restoration of freshwater conditions may, in some way, allow the recovery of the zooplankton community from viable egg banks. Our results can be useful in predicting the influence of glyphosate on the distribution patterns of freshwater zooplankton, which can represent vital information for environmental managers.

In vitro activation of ovarian cortex and autologous transplantation: A novel approach to primary ovarian insufficiency and diminished ovarian reserve.

BACKGROUND: Primary ovarian insufficiency (POI) and diminished ovarian reserve are two conditions that affect women's fertility. Oocyte donation remains an option for these patients; however, the development of certain novel technologies, such as in vitro activation of ovarian cortex (IVA), enables the possibility of activating the pool of resting primordial follicles, increasing the chance of pregnancy. OBJECTIVE AND RATIONALE: Here, we review the main pathways (PI3K and Hippo signaling) that govern the activation of primordial follicles and its application through the development of culture systems that support ovarian cortex for autologous transplantation. We also review the available data from case reports regarding outcomes of pregnancy and live birth rates with IVA. SEARCH METHODS: A PubMed search was conducted using the PubMed-NCBI database to identify literature pertinent to the pathways involved in the activation of primordial follicles and the outcomes of IVA techniques from 2013 to the present. OUTCOMES: Women with POI have around a 5% chance of spontaneous pregnancy. Recently, novel techniques involving the activation of primordial follicles through molecular pathways have been developed, thus increasing the odds of these patients. More recently, the introduction of a drug-free IVA technique has shown to increase the number of antral follicles with successful oocyte maturation after gonadotropin treatment, reaching pregnancy rates over 30%, either through spontaneous conception or by the implementation of assisted reproductive technology. LIMITATIONS: The evidence of this review is based on a few small series, so data should be interpreted with caution, and only randomized controlled trials could estimate the real magnitude and success of the procedure. REASONS FOR CAUTION: IVA technique remains an experimental strategy, with limited available data and the requirement of invasive procedures. Moreover, possible carcinogenic effects not yet determined after transplantation require special caution. WIDER IMPLICATIONS: In view of the results achieved, IVA could provide a promising option for the preservation of fertility in some cancer patients and prepuberal girls where the only alternative is tissue cryopreservation. STUDY FUNDING/COMPETING INTERESTS: The authors received no specific funding for this work and declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Susceptibility of the floodwater mosquito Aedes albifasciatus from eggs of different dormancy times to the nematode parasite Strelkovimermis spiculatus.

This study aimed to evaluate the effects of egg dormancy times on susceptibility of larvae of the floodwater mosquito Aedes albifasciatus (Diptera: Culicidae) to parasitism by their natural enemy Strelkovimermis spiculatus (Nematoda: Mermithidae) and on their life history traits. Aedes albifasciatus eggs stored for 2, 4, 6, 8 and 10 months were hatched, and the larvae either exposed to S. spiculatus (treatment group) or not exposed (control group). Egg dormancy time had a negative effect on the retention of parasites, but no effect on the prevalence and intensity of parasitism or the melanization of nematodes. The survival to adulthood of control individuals decreased as dormancy time increased, whereas that of exposed individuals that remained uninfected was constant and low. A trend towards increasing development times with longer dormancy times was detected in the control group, but not in the exposed noninfected group. The results suggest nonconsumptive effects of parasites in exposed but not infected larvae from eggs with short dormancy times. In contrast, the relatively low fitness of larvae from eggs with long dormancy times regardless of their contact with the nematodes may be the result of the nutritional deprivation during the egg stage.

Mixture of commercial herbicides based on 2,4-D and glyphosate mixture can suppress the emergence of zooplankton from sediments.

It is generally assumed that zooplankton can recolonize lakes that have been exposed to pesticides, via their dormant egg banks. Hitherto, few studies have evaluated the relative importance of dormant egg bank recruitment in the re-establishment of zooplankton communities in the presence of pesticide. This study investigated the effects of commercial products Bratt® (a.i. 2,4-D), Roundup® (a.i. glyphosate) and their mixture on the emergence (abundance and taxon richness) of dormant zooplankton egg banks from natural lake sediment. Sediment samples were collected from the surface sediment (<10 cm depth) in four lakes in Southeast São Paulo, Brazil. We performed a hatching experiment, in which natural lake sediments containing dormant eggs were exposed separately to Bratt® (applied concentrations ranging from 0.30 to 20 mg L-1), Roundup® (0.28-8.5 mg L-1), and combined mixtures of all concentrations, plus one control (non-exposure to formulated herbicides) for a period of 28 days. All tested concentrations of Bratt®, Roundup® and their mixture reduced the abundance and taxon richness of emerging zooplankton (except 2 mg L-1 of Bratt®). This effect was more pronounced in rotifers. In comparison, there were no negative effects on the emergence of microcrustaceans. These findings suggest that commercial products Bratt®, Roundup® and their mixture can suppress the emergence of rotifers, thereby influencing zooplankton recruitment potential in lakes impacted by the presence of these commercial herbicides. Our results stress the importance of the need for additional studies to assess the effects of pesticides on dormant egg banks.

Morphology, ecophysiology and germination of seeds of the Neotropical tree Alibertia patinoi (Rubiaceae) / Morfología, ecofisiología y germinación de semillas del árbol neotropical

Alibertia patinoi (Rubiaceae). Alibertia patinoi (Rubiaceae) is of economic and cultural importance for communities in the Colombian Pacific and Amazon regions, where it is cultivated and mature fruits are highly appreciated and consumed. Since there is a lack of knowledge of the seed physiology of this species, we describe here the germination behavior and morphometry of seeds of Alibertia patinoi, and relate them to its habitat. Fruits were collected from a mixed food crop and a commercial plantation in Guaimía village, Buenaventura, Colombia, a tropical rain forest area. We measured length, width, thickness, mass (n=1 400), and moisture content of seeds (n=252). Primary dormancy tests were conducted (n=200), followed by imbibition (n=252) and germination dynamics, under different conditions of light and temperature specific to understory and forest clearings (n=300 seeds). Finally, seed storage behavior was established (n=100 seeds). We observed that size and mass of seeds had a narrow range of values that did not differ within or among fruits and that the species did not exhibit primary dormancy. The seeds are recalcitrant, and recently harvested seeds exhibited higher seed moisture content (ca. 44%) and continuous metabolism. The seed germination percentage was observed to be higher under the specific dense canopy forest light and temperature conditions; furthermore, neither enriched far-red light nor darkness conditions inhibited germination. We concluded that rapid germination could be the establishment strategy of this species. Also, the physiological traits (i.e., rapid germination rate, low germination requirements, absence of primary dormancy, and recalcitrant behavior) and seed size and mass, suggest that A. patinoi is adapted to conditions of mature tropical rain forests.

La germinación y morfometría de las semillas de Alibertia patinoi se describen y se relacionan con el hábitat de la especie, el Bosque Pluvial Tropical Americano. Se midió la longitud, ancho, grosor, peso y contenido de humedad de las semillas. Se realizaron pruebas de latencia, imbibición y dinámica de la germinación con diferentes condiciones de luz y temperatura específicas de claros y de sotobosque cubierto por un dosel denso. Además, se estableció el comportamiento de almacenamiento de las semillas. El tamaño y peso de las semillas no difieren dentro ni entre frutos. Las semillas recién cosechadas no tienen latencia primaria, presentan alto contenido de humedad (ca. 44%), metabolismo continuo y son recalcitrantes. La germinación tuvo porcentajes altos y en condiciones de luz y temperatura específicas de bosque con follaje denso, y ni la luz enriquecida con rojo lejano ni la oscuridad inhibieron la germinación. Se concluye que la germinación rápida podría ser la estrategia de establecimiento de esta especie. Además, los rasgos fisiológicos, el tamaño y peso de las semillas, sugieren que A. patinoi está adaptada a las condiciones del bosque lluvioso tropical maduro y se comporta como una especie que no es pionera.

Urea levels in multiple supplement for lambs grazing on buffelgrass / Teores de uréia no suplemento múltiplo de cordeiros mantidos em pastos de capim-búffel

The objective of present trial was to evaluate the intake of supplement dry matter, productive performance, carcass traits, and weight and yields of commercial meat cuts of lambs grazing on dormant buffelgrass pastures and receiving multiple supplementation containing different urea levels. Urea levels used were: 5, 8, 11 and 14% on dry matter. Thirty-six male lambs were used, nine animals per treatment, with 18.0 ± 2.0 kg initial body weight, distributed into four groups. The experimental design was completely randomized with nine replications. Urea levels in supplement did not influence productive performance, cold and hot carcass weight and yield and commercial meat cuts weight and yield (leg, shoulder, rib and brisket). Use of multiple supplements containing 11 and 14% of urea levels for lambs in dormant grazing pastures during the dry season may increase bioeconomic performance of this activity, as they promoted lower supplement intake and similar productive performance.

O objetivo do presente estudo foi avaliar o consumo de matéria seca de suplemento, o desempenho produtivo, os parâmetros de carcaça e os rendimentos de cortes cárneos comerciais de cordeiros mantidos em pastos diferidos de capim-búffel recebendo suplementos múltiplos com diferentes teores de uréia. Foram utilizados quatro teores de uréia, sendo 5, 8, 11 e 14% na matéria seca. Foram utilizados 36 cordeiros machos, nove animais por tratamento, com peso corporal inicial médio de 18,0 ± 2,0 kg, distribuídos em quatro grupos. O delineamento experimental adotado foi o inteiramente casualizado com nove repetições. Os teores de uréia no concentrado não influenciaram os ganhos médios diários, os ganhos de peso totais, os pesos corporais finais, os pesos e os rendimentos de carcaça quente e fria e os pesos e rendimentos de cortes cárneos comerciais (pernil, paleta, costela e carré). O fornecimento de suplementos múltiplos contendo 11 e 14% de uréia para ovinos criados em pastagens diferidas na estação seca resultaram em melhores desempenhos bioeconômicos para a atividade, já que, com menores consumos de suplemento os animais atingiram desempenhos semelhantes.

Urea levels in multiple supplement for lambs grazing on buffelgrass / Teores de uréia no suplemento múltiplo de cordeiros mantidos em pastos de capim-búffel

The objective of present trial was to evaluate the intake of supplement dry matter, productive performance, carcass traits, and weight and yields of commercial meat cuts of lambs grazing on dormant buffelgrass pastures and receiving multiple supplementation containing different urea levels. Urea levels used were: 5, 8, 11 and 14% on dry matter. Thirty-six male lambs were used, nine animals per treatment, with 18.0 ± 2.0 kg initial body weight, distributed into four groups. The experimental design was completely randomized with nine replications. Urea levels in supplement did not influence productive performance, cold and hot carcass weight and yield and commercial meat cuts weight and yield (leg, shoulder, rib and brisket). Use of multiple supplements containing 11 and 14% of urea levels for lambs in dormant grazing pastures during the dry season may increase bioeconomic performance of this activity, as they promoted lower supplement intake and similar productive performance.(AU)

O objetivo do presente estudo foi avaliar o consumo de matéria seca de suplemento, o desempenho produtivo, os parâmetros de carcaça e os rendimentos de cortes cárneos comerciais de cordeiros mantidos em pastos diferidos de capim-búffel recebendo suplementos múltiplos com diferentes teores de uréia. Foram utilizados quatro teores de uréia, sendo 5, 8, 11 e 14% na matéria seca. Foram utilizados 36 cordeiros machos, nove animais por tratamento, com peso corporal inicial médio de 18,0 ± 2,0 kg, distribuídos em quatro grupos. O delineamento experimental adotado foi o inteiramente casualizado com nove repetições. Os teores de uréia no concentrado não influenciaram os ganhos médios diários, os ganhos de peso totais, os pesos corporais finais, os pesos e os rendimentos de carcaça quente e fria e os pesos e rendimentos de cortes cárneos comerciais (pernil, paleta, costela e carré). O fornecimento de suplementos múltiplos contendo 11 e 14% de uréia para ovinos criados em pastagens diferidas na estação seca resultaram em melhores desempenhos bioeconômicos para a atividade, já que, com menores consumos de suplemento os animais atingiram desempenhos semelhantes.(AU)