Laboratory activity to effectively teach introductory geomicrobiology concepts to non-geology majors

We have designed a three-week experiment that can complement any microbiology course, to teach main geomicrobiology concepts for non-geology majors. One of the most difficult concepts for non-geology majors to comprehend is how bacteria serve as a platform for different mineralization reactions. In our three-week laboratory practice, students learn the main principles and conditions required for an induced bacterial mineralization. Upon completion of the laboratory experience, students will: 1) learn how microbial-induced mineralization (such as calcium carbonate formation) is affected by differential media and growth conditions; 2) understand how bacterial physiology affects any induced in situ or in vitro mineralization; 3) comprehend how growing conditions and bacterial physiologies interrelate, resulting in differential crystal formation. The teaching-learning process was assessed using a pre-/posttest with an increase from 26% to 76% in the number of positive answers from the students. We also measured the students' proficiency while conducting specific technical tasks, revealing no major difficulties while conducting the experiments. A final questionnaire was provided with satisfactory evaluations from the students regarding the organization and content of the practices. 84-86% of the students agreed that the exercises improved their knowledge in geomicrobiology and would like to attend similar laboratories in the future. Such response is the best indicator that the laboratory practice can be implemented in any undergraduate/graduate microbiology course to effectively teach basic geomicrobiology concepts to non-geology majors

Laboratory activity to effectively teach introductory geomicrobiology concepts to non-geology majors

We have designed a three-week experiment that can complement any microbiology course, to teach main geomicrobiology concepts for non-geology majors. One of the most difficult concepts for non-geology majors to comprehend is how bacteria serve as a platform for different mineralization reactions. In our three-week laboratory practice, students learn the main principles and conditions required for an induced bacterial mineralization. Upon completion of the laboratory experience, students will: 1) learn how microbial-induced mineralization (such as calcium carbonate formation) is affected by differential media and growth conditions; 2) understand how bacterial physiology affects any induced in situ or in vitro mineralization; 3) comprehend how growing conditions and bacterial physiologies interrelate, resulting in differential crystal formation. The teaching-learning process was assessed using a pre-/posttest with an increase from 26% to 76% in the number of positive answers from the students. We also measured the students' proficiency while conducting specific technical tasks, revealing no major difficulties while conducting the experiments. A final questionnaire was provided with satisfactory evaluations from the students regarding the organization and content of the practices. 84-86% of the students agreed that the exercises improved their knowledge in geomicrobiology and would like to attend similar laboratories in the future. Such response is the best indicator that the laboratory practice can be implemented in any undergraduate/graduate microbiology course to effectively teach basic geomicrobiology concepts to non-geology majors

Effect of fast acting power controller of battery energy storage systems in the under-frequency load shedding scheme

This paper presents the assessment of the effect of fast acting power (FAP) controller in the battery energy storage system (BESS) the under-frequency load shedding (UFLS) scheme. Theoretical and practical discussions about the implementation of inertia frequency control for BESS are presented in this paper. The effect of changes in the gain of the synthetic inertial on the system frequency response is investigated using time domain simulations based on DIgSILENT PowerFactory

eDNA and specific primers for early detection of invasive species – A case study on the bivalve Rangia cuneata, currently spreading in Europe

Intense human activities facilitate the successful spread and establishment of non-indigenous aquatic organisms in marine and freshwater ecosystems. In some cases such intrusions result in noticeable and adverse changes in the recipient environments. In the Baltic Sea, the discovery and rapid initial spread of the North American wedge clam Rangia cuneata represents a new wave of invasion which may trigger unpredictable changes of the local benthic communities. In this study we present a species-specific DNA-based marker developed in silico and experimentally tested on environmental samples. Marker specificity and sensitivity were assessed in vitro from water samples containing different mixtures of the target species and other five bivalves currently present in the region: the native Cerastoderma glaucum, Macoma balthica and Mytilus trossulus, the invasive Dreissena polymorpha and the cryptogenic Mya arenaria. Cross-species amplification was not found in any case. The method allows to detecting at least 0.4 ng of Rangia cuneata DNA per μl, and 0.1 g of tissue per liter of water. Finally, the marker performance was assessed in water samples from the Baltic Sea and Vistula Lagoon. The coincidence between independent visual observations of Rangia cuneata and positive PCR amplification of the marker from the water samples confirmed the efficiency of this highly reproducible, fast, and technically easy method. Rangia cuneata traces can be detected from environmental DNA even when the population is sparse and small, enabling rapid management responses and allowing to track the invasion dynamics

Are superficial neuromasts proprioceptors underlying fast copulatory behavior?

In male Poeciliid fishes, the modified anal fin (i.e., gonopodium) and its axial and appendicular support are repositioned within the axial skeleton, creating a novel sexually dimorphic ano-urogenital region. During copulation, the relative location of the gonopodium is crucial for successful insemination. Therefore, the repositioning of these structures and organ relied on the reorganization of the efferent circuitry that controls spinal motor neurons innervating appendicular muscles critical for the movement of the gonopodium, including the fast and synchronous torque-trust motion during insemination attempts. Copulation occurs when a male positions himself largely outside a female’s field of view, circumducts his gonopodium, and performs a rapid, complex maneuver to properly contact the female urogenital sinus with the distal tip of the gonopodium and transfers sperm. Although understanding of the efferent circuitry has significantly increased in the last 24 years, nothing is known about the cutaneous receptors involved in gonopodium movement, or how the afferent signals are processed to determine the location of this organ during copulation. Using Western mosquitofish, Gambusia affinis, as our model, we attempt to fill this gap in knowledge. Preliminary data showed cutaneous nerves and sensory neurons innervating superficial neuromasts surrounding the base of adult male gonopodium; those cutaneous nerves projected ventrally from the spinal cord through the 14th dorsal root ganglion and its corresponding ventral root towards the base and fin rays of the gonopodium. We asked what role the cutaneous superficial neuromasts play in controlling the positioning and timing of the gonopodium’s fast and synchronous movements for effective sperm transfer. First, we found a greater number of superficial neuromasts surrounding the base of the male’s gonopodium compared to the base of the female’s anal fin. Second, we systemically removed superficial neuromasts surrounding the gonopodium base and observed significant impairment of the positioning and timing of gonopodial movements. Our findings provide a first step to supporting the following hypothesis: during radical reorganization of the Poeciliid body plan, superficial neuromasts have been partially co-opted as proprioceptors that allow the gonopodium to control precise positioning and timing during copulatory attempts

Comunicación corta. Diferenciación de cepas vacunales del virus del síndrome reproductor y respiratorio porcino de tipo I y cepas de campo por análisis de polimorfismos en la longitud de fragmentos de restricción

The use of modified live virus (MLV) vaccines is a common procedure to control porcine reproductive and respiratory syndrome virus (PRRSV) infection in the great majority of countries from America, Asia and Europe, including Spain. Current discriminatory techniques allow the detection of different MLV type-II vaccine strains. Herein we report a rapid and accurate technique aimed to discriminate between MLV type-I vaccine strains and Spanish field strains. This technique comprises a reverse transcription (RT) and nested polymerase chain reaction (nPCR) amplification of PRRSV ORF5 followed by a digestion of RT-nPCR products with two specific endonucleases, ItaI and AccI. Combined utilization of ItaI and AccI generates restriction fragments length polymorphisms (RFLP) patterns adequate for the differentiation of 30 Spanish field isolates, of which 12 were isolated between 1991 and 1995 and 18 between 2000 and 2003. These different RFLP patterns can be used to distinguish unequivocally between Spanish field strains of PRRSV and the three MLV type-I vaccines used in Spain: AmervacPRRS®, Pyrsvac-183® and PorcilisPRRS®.Para controlar la infección por el virus del síndrome reproductor y respiratorio porcino (PRRSV), en la gran mayoría de países de América, Asia y Europa, incluyendo España, se usan frecuentemente vacunas basadas en virus vivos modificados (MLV). En la actualidad existen técnicas discriminatorias que permiten detectar cepas vacunales del PRRSV de tipo II. El presente trabajo describe una técnica precisa y rápida para la diferenciación de cepas vacunales de tipo I del PRRSV y cepas de campo españolas. Esta técnica se basa en la transcripción reversa y posterior amplificación de la ORF5 del genoma del PRRSV utilizando la reacción en cadena de la polimerasa anidada, seguida de la digestión de los amplicones generados con dos endonucleasas específicas: ItaI y AccI. La utilización combinada de ambas enzimas genera patrones de polimorfismos en la longitud de fragmentos de restricción (RFLP), adecuados para la distinción de las 30 cepas de campo usadas, de las cuales 12 fueron aisladas entre 1991 y 1995 y 18 entre 2000 y 2003. Estos diferentes patrones pueden ser utilizados para distinguir entre cepas de campo españolas del PRRSV y las tres cepas vacunales de tipo I usadas en España: AmervacPRRS®, Pyrsvac-183® y PorcilisPRRS®

Loose ends: almost one in five human genes still have unresolved coding status

Seventeen years after the sequencing of the human genome, the human proteome is still under revision. One in eight of the 22 210 coding genes listed by the Ensembl/GENCODE, RefSeq and UniProtKB reference databases are annotated differently across the three sets. We have carried out an in-depth investigation on the 2764 genes classified as coding by one or more sets of manual curators and not coding by others. Data from large-scale genetic variation analyses suggests that most are not under protein-like purifying selection and so are unlikely to code for functional proteins. A further 1470 genes annotated as coding in all three reference sets have characteristics that are typical of non-coding genes or pseudogenes. These potential non-coding genes also appear to be undergoing neutral evolution and have considerably less supporting transcript and protein evidence than other coding genes. We believe that the three reference databases currently overestimate the number of human coding genes by at least 2000, complicating and adding noise to large-scale biomedical experiments. Determining which potential non-coding genes do not code for proteins is a difficult but vitally important task since the human reference proteome is a fundamental pillar of most basic research and supports almost all large-scale biomedical projects.National Institutes of Health [2 U41 HG007234 to I.J., L.M., J.M.R. and M.L.T., R01 HG004037 to I.J.]. Funding for open access charge: NIH [2 U41 HG007234].S