Neural Correlates of Social Behavior in Mushroom Body Extrinsic Neurons of the Honeybee Apis mellifera

The social behavior of honeybees (Apis mellifera) has been extensively investigated, but little is known about its neuronal correlates. We developed a method that allowed us to record extracellularly from mushroom body extrinsic neurons (MB ENs) in a freely moving bee within a small but functioning mini colony of approximately 1,000 bees. This study aimed to correlate the neuronal activity of multimodal high-order MB ENs with social behavior in a close to natural setting. The behavior of all bees in the colony was video recorded. The behavior of the recorded animal was compared with other hive mates and no significant differences were found. Changes in the spike rate appeared before, during or after social interactions. The time window of the strongest effect on spike rate changes ranged from 1 s to 2 s before and after the interaction, depending on the individual animal and recorded neuron. The highest spike rates occurred when the experimental animal was situated close to a hive mate. The variance of the spike rates was analyzed as a proxy for high order multi-unit processing. Comparing randomly selected time windows with those in which the recorded animal performed social interactions showed a significantly increased spike rate variance during social interactions. The experimental set-up employed for this study offers a powerful opportunity to correlate neuronal activity with intrinsically motivated behavior of socially interacting animals. We conclude that the recorded MB ENs are potentially involved in initiating and controlling social interactions in honeybees

Age Polyethism in Atta sexdens (Linnaeus) (Hymenoptera: Formicidae)

This study aimed to verify age polyethism occurrence in medium-sized (cephalic capsule = 2.3 ± 0.21 mm) and small-sized (cc = 1.4 ± 0.10 mm) workers from Atta sexdens (Linnaeus) colonies. Four laboratory colonies were used, and they were maintained at 25 ± 2 °C, with 75 ± 3% relative humidity and a 12-hour photoperiod. Workers from these colonies were marked after their emergence and observed throughout their lifetime to determine which tasks they performed. The number of ants performing each activity was analyzed using linear mixed-effect models (LME), considering the temporal effect and the block design (colonies). We found that fungal garden maintenance tasks were frequent for both sizes, but their occurrence decreased significantly from the ninth week. The foraging activity occurred gradually in both sizes, with stabilization in the number of workers from the fourth week onwards and declined in the last three weeks of lifespan. Waste management tasks occurred throughout life but were more frequent during the first two weeks of life, in both medium and small workers. Therefore, age polyethism may be related to all activities; however, foraging tasks presented a distinct pattern compared to tasks in the fungus garden and refuse dump, where younger ants were more frequently observed

Do microplastics affect the zoanthid Zoanthus sociatus?

Microplastics (1 μm-5 mm), a ubiquitous and persistent marine pollutant, pose a severe threat to coral reefs when recently associated with physiological distress and increased diseases on corals. Studies conducted so far have only reported effects on scleractinian species. Knowledge about its effects on other corals (e.g. Order Zoantharia) remains uncovered, and responses at biochemical levels remain poorly documented. This study aimed to assess the potential effects induced by the presence of microplastics (1 and 10 mg L-1 low-density polyethylene, LDPE MP, or polyvinyl chloride, PVC MP) in the tropical and subtropical cosmopolitan species Zoanthus sociatus (order Zoantharia. Anthozoa: Hexacorallia), at organism level (survival and behaviour), endosymbionts (photosynthetic efficiency) and the cellular level (oxidative stress, detoxification capacity and energy metabolism). In a short-term exposure (96 h), this species was more sensitive to PVC MP. The presence of this polymer at a concentration of 10 mg L-1 caused a ten-fold higher adhesion to the coral epidermis, increased photosynthetic efficiency, lipid peroxidation, and antioxidant defences; without, however, inducing energetic costs. Although the observed physiological and biochemical effects did not compromise Z. sociatus survival in the short term, it does not rule out potential long-term (cumulative) effects that could endanger this and other physiologically similar species that underlie coral reefs.publishe

STERILISASI MIKROBA BUBUK TALC MENGGUNAKAN SINAR GAMMA (Co-60)

Kerusakan produk bedak talek umumnya disebabkan oleh pertumbuhan mikroba. Beberapa industri mengatasi masalah ini dengan menggunakan teknik pengawetan iradiasi sinar gamma (Cobalt-60). Penelitian ini mengidentifikasi jumlah mikroba yang tersisa dalam bedak talek dan struktur sel bakteri yang diiradiasi. Pada studi pendahuluan, proses iradiasi dilakukan dengan memberikan dosis iradiasi bedak talek yang terdiri dari 4 taraf yaitu 0kGy, 5kGy, 7kGy, dan 9kGy yang dilakukan di PT. Rel-ion Bekasi menggunakan sinar gamma irradiator (Co-60), dan dilanjutkan dengan uji mikrobiologi terhadap sisa mikroba dalam bedak talk yang diradiasi yang dilakukan di Laboratorium Biokimia Fakultas Sains Universitas Brawijaya. Pengujian terdiri dari penghitungan jumlah bakteri dengan metode plate count dan identifikasi struktur sel bakteri dominan menggunakan metode pewarnaan gram dan pengamatan mikroskopis. Hasil penelitian menunjukkan bahwa jumlah bakteri pada bedak talek menurun seiring dengan meningkatnya dosis iradiasi. Identifikasi struktur sel bakteri yang dominan pada bedak talk yang diiradiasi menunjukkan ciri-ciri bakteri Pseudomonas aeruginosa dengan koloni bulat, licin, putih, memberikan pigmen kehijauan pada medium, dan menunjukkan sel bakteri gram negatif, dengan struktur batang, kadang-kadang bergandengan dan bercabang tidak beraturan dan berwarna merah.Kerusakan produk bedak talek umumnya disebabkan oleh pertumbuhan mikroba. Beberapa industri mengatasi masalah ini dengan menggunakan teknik pengawetan iradiasi sinar gamma (Cobalt-60). Penelitian ini mengidentifikasi jumlah mikroba yang tersisa dalam bedak talek dan struktur sel bakteri yang diiradiasi. Pada studi pendahuluan, proses iradiasi dilakukan dengan memberikan dosis iradiasi bedak talek yang terdiri dari 4 taraf yaitu 0kGy, 5kGy, 7kGy, dan 9kGy yang dilakukan di PT. Rel-ion Bekasi menggunakan sinar gamma irradiator (Co-60), dan dilanjutkan dengan uji mikrobiologi terhadap sisa mikroba dalam bedak talk yang diradiasi yang dilakukan di Laboratorium Biokimia Fakultas Sains Universitas Brawijaya. Pengujian terdiri dari penghitungan jumlah bakteri dengan metode plate count dan identifikasi struktur sel bakteri dominan menggunakan metode pewarnaan gram dan pengamatan mikroskopis. Hasil penelitian menunjukkan bahwa jumlah bakteri pada bedak talek menurun seiring dengan meningkatnya dosis iradiasi. Identifikasi struktur sel bakteri yang dominan pada bedak talk yang diiradiasi menunjukkan ciri-ciri bakteri Pseudomonas aeruginosa dengan koloni bulat, licin, putih, memberikan pigmen kehijauan pada medium, dan menunjukkan sel bakteri gram negatif, dengan struktur batang, kadang-kadang bergandengan dan bercabang tidak beraturan dan berwarna merah

In-depth characterization of denitrifier communities across different soil ecosystems in the tundra

Background In contrast to earlier assumptions, there is now mounting evidence for the role of tundra soils as important sources of the greenhouse gas nitrous oxide (N2O). However, the microorganisms involved in the cycling of N2O in this system remain largely uncharacterized. Since tundra soils are variable sources and sinks of N2O, we aimed at investigating differences in community structure across different soil ecosystems in the tundra. Results We analysed 1.4 Tb of metagenomic data from soils in northern Finland covering a range of ecosystems from dry upland soils to water-logged fens and obtained 796 manually binned and curated metagenome-assembled genomes (MAGs). We then searched for MAGs harbouring genes involved in denitrification, an important process driving N2O emissions. Communities of potential denitrifiers were dominated by microorganisms with truncated denitrification pathways (i.e., lacking one or more denitrification genes) and differed across soil ecosystems. Upland soils showed a strong N2O sink potential and were dominated by members of the Alphaproteobacteria such as Bradyrhizobium and Reyranella. Fens, which had in general net-zero N2O fluxes, had a high abundance of poorly characterized taxa affiliated with the Chloroflexota lineage Ellin6529 and the Acidobacteriota subdivision Gp23. Conclusions By coupling an in-depth characterization of microbial communities with in situ measurements of N2O fluxes, our results suggest that the observed spatial patterns of N2O fluxes in the tundra are related to differences in the composition of denitrifier communities.Peer reviewe

Germinados de trigo kamut (Triticum turgidum), quinua (Chenopodium quinoa) y frijol mungo (Vigna radiata): Una alternativa para la alimentación de colonias de hormigas Atta cephalotes en condiciones de laboratorio.

The establishment of colonies of Atta cephalotes cutter ants under laboratory conditions has been proposed for the study and development of plague control products. However, few laboratories in Colombia have colonies of Atta cephalotes cutter ants, with food being a limiting factor given their sensitivity, selectivity and voracity. In this study, the use of wheat germinated kamut (Triticum turgidum), quinoa (Chenopodium quinoa) and mung bean (Vigna radiata) as an alternative for the feeding of colonies under laboratory conditions y mango leaves like control, using mini-colonies was evaluated. In the study, mung bean sprouts and kamut wheat were preferred (100% load, 24 hours), compared to quinoa (89 ± 10% load, 24 hours). The determination of the effect of the sprouts on the growth rate of the mini-colonies was evaluated during 8 weeks, showing that the germinated kamut wheat and control treatment generated the best growth rates of fungus in the exponential phase (3.19 and 3.73 g / week respectively) compared with mung beans and quinoa (1 g / wk), supporting the potential of kamut wheat for the maintenance of colonies under laboratory conditions.En este artículo, se muestra la metodología para evaluar los efectos lineales y no lineales presentes en un sistema de radio sobre fibra óptica (Radio over Fibre, RoF) empleando la técnica multiplexacion por división de onda densa (Dense Wavelenght Division Multiplexing, DWDM) con esparcimientos de 50GHz, según las normas de la Unión Internacional de Telecomunicaciones (International Telecommunication Union, ITU) con una velocidad de canal de 10 Gbps, a una potencia de entrada en el canal óptico de 30mW, para tramos de fibra óptica de 40km, 60km y 80km. Se presenta el modelado del sistema de RoF representado en forma gráfica a través de diagrama de bloques por medio de la herramienta computacional Matlab, donde se implementan cada una de las etapas del sistema de RoF usando las librerías ofrecidas por el Toolbox de simulink de Matlab. Como resultado se obtiene que la metodología propuesta para la evaluación del sistema RoF empleando la técnica DWDM permite analizar los efectos lineales y no lineales; donde se observa que los efectos que degradan la señal son proporcionales a las distancias de la fibra óptica establecidas y que la potencia óptica de entrada empleada es óptima para que la fibra óptica se comporte como medio no lineal.  &nbsp

Isolation and characterization of Acidobacterium ailaaui sp. Nov., a novel member of Acidobacteria subdivision 1, from a geothermally heated Hawaiian microbial mat

© 2016 IUMS. A novel member of Acidobacteria was isolated from a microbial mat growing on a geothermally heated dead tree trunk in Hawai\u27i Volcanoes National Park (HI, USA). The rod-shaped, Gramnegative capsulated cells of strain PMMR2T were non-motile and catalase and oxidase negative. Growth occurred aerobically from 15 to 55 °C (optimum, 40 °C) and at pH values from 4.5 to 7.0 (optimum, 6.5). A limited range of sugars and organic acids supported growth. However, results of a genomic analysis suggested that various polysaccharides might be hydrolysed as carbon sources, and evidence for pectin degradation was observed in liquid cultures. A genomic analysis also revealed genes for a Group 1f uptake hydrogenase; assays with liquid cultures confirmed hydrogen consumption, including uptake at sub-atmospheric concentrations. Nitrate was not dissimilated to nitrite. Major membrane fatty acids included iso- C15: 0 and iso-C17: 0. The G+C content was 57.2mol%. A comparative genome analysis revealed an average nucleotide identity of 72.2% between PMMR2T and its nearest cultured phylogenetic neighbour, Acidobacterium capsulatum ATCC 51196T (=JCM 7670T); analysis of the 16S rRNA gene revealed a 96.8% sequence identity with Acidobacterium capsulatum ATCC 51196T. These results and other phenotypic differences indicated that strain PMMR2T represents a novel species in the genus Acidobacterium, for which the name Acidobacterium ailaaui sp. nov. is proposed. The type strain, PMMR2T (=DSM 27394T=LMG 28340T), is the second formal addition to the genus Acidobacterium

Biomarker- and similarity coefficient-based approaches to bacterial mixture characterization using matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS)

abstract: MALDI-TOF MS profiling has been shown to be a rapid and reliable method to characterize pure cultures of bacteria. Currently, there is keen interest in using this technique to identify bacteria in mixtures. Promising results have been reported with two- or three-isolate model systems using biomarker-based approaches. In this work, we applied MALDI-TOF MS-based methods to a more complex model mixture containing six bacteria. We employed: 1) a biomarker-based approach that has previously been shown to be useful in identification of individual bacteria in pure cultures and simple mixtures and 2) a similarity coefficient-based approach that is routinely and nearly exclusively applied to identification of individual bacteria in pure cultures. Both strategies were developed and evaluated using blind-coded mixtures. With regard to the biomarker-based approach, results showed that most peaks in mixture spectra could be assigned to those found in spectra of each component bacterium; however, peaks shared by two isolates as well as peaks that could not be assigned to any individual component isolate were observed. For two-isolate blind-coded samples, bacteria were correctly identified using both similarity coefficient- and biomarker-based strategies, while for blind-coded samples containing more than two isolates, bacteria were more effectively identified using a biomarker-based strategy.The final version of this article, as published in Scientific Reports, can be viewed online at: https://www.nature.com/articles/srep1583