Search

Detonation nanodiamond (DND) is the smallest class of diamond nanocrystal capable of hosting various color centers with a size akin to molecular pores. Their negatively charged nitrogen-vacancy center (NV−) is a versatile tool for sensing a wide range of physical and even chemical parameters at the nanoscale. The NV− is, therefore, attracting interest as the smallest quantum sensor in biological research. Nonetheless, recent NV− enhancement in DND has yet to yield sufficient fluorescence per particle, leading to efforts to incorporate other group-IV color centers into DND. An example is adding a silicon dopant to the explosive mixture to create negatively charged silicon-vacancy centers (SiV−). In this paper, we report on efficient observation (∼50% of randomly selected spots) of the characteristic optically detected magnetic resonance (ODMR) NV− signal in silicon-doped DND (Si-DND) subjected to boiling acid surface cleaning. The NV− concentration is estimated by continuous-wave electron spin resonance spectroscopy to be 0.35 ppm without the NV− enrichment process. A temperature sensitivity of 0.36K/Hz in an NV− ensemble inside an aggregate of Si-DND is achieved via the ODMR-based technique. Transmission electron microscopy survey reveals that the Si-DNDs core sizes are ∼11.2 nm, the smallest among the nanodiamond’s temperature sensitivity studies. Furthermore, temperature sensing using both SiV− (all-optical technique) and NV− (ODMR-based technique) in the same confocal volume is demonstrated, showing Si-DND’s multimodal temperature sensing capability. The results of the study thereby pave a path for multi-color and multimodal biosensors and for decoupling the detected electrical field and temperature effects on the NV− center.

The ongoing controversies about the neural basis of tinnitus, whether linked with central neural gain or not, may hamper efforts to develop therapies. We asked to what extent measurable audiometric characteristics of tinnitus without (T) or with co-occurrence of hyperacusis (TH) are distinguishable on the level of cortical responses. To accomplish this, electroencephalography (EEG) and concurrent functional near-infrared spectroscopy (fNIRS) were measured while patients performed an attentionally demanding auditory discrimination task using stimuli within the individual tinnitus frequency (fTin) and a reference frequency (fRef). Resting-state-fMRI-based functional connectivity (rs-fMRI-bfc) in ascending auditory nuclei (AAN), the primary auditory cortex (AC-I), and four other regions relevant for directing attention or regulating distress in temporal, parietal, and prefrontal cortex was compiled and compared to EEG and concurrent fNIRS activity in the same brain areas. We observed no group differences in pure-tone audiometry (PTA) between 10 and 16 kHz. However, the PTA threshold around the tinnitus pitch was positively correlated with the self-rated tinnitus loudness and also correlated with distress in T-groups, while TH experienced their tinnitus loudness at minimal loudness levels already with maximal suffering scores. The T-group exhibited prolonged auditory brain stem (ABR) wave I latency and reduced ABR wave V amplitudes (indicating reduced neural synchrony in the brainstem), which were associated with lower rs-fMRI-bfc between AAN and the AC-I, as observed in previous studies. In T-subjects, these features were linked with elevated spontaneous and reduced evoked gamma oscillations and with reduced deoxygenated hemoglobin (deoxy-Hb) concentrations in response to stimulation with lower frequencies in temporal cortex (Brodmann area (BA) 41, 42, 22), implying less synchronous auditory responses during active auditory discrimination of reference frequencies. In contrast, in the TH-group gamma oscillations and hemodynamic responses in temporoparietal regions were reversed during active discrimination of tinnitus frequencies. Our findings suggest that T and TH differ in auditory discrimination and memory-dependent directed attention during active discrimination at either tinnitus or reference frequencies, offering a test paradigm that may allow for more precise sub-classification of tinnitus and future improved treatment approaches.

The impact of fossil fuel utilisation in different combustion systems on climate change due to greenhouse gas accumulation in the atmosphere is rather evident. A part of these gases comes from the large engines used for propulsion in marine applications. In the continuous global effort made by engine manufacturers to mitigate this negative impact, one way is represented by the utilisation of alternative fuels such as biodiesel and methanol, based on dedicated research to fulfil the more stringent regulations concerning pollutant emissions issued by piston heat engines. In this study, a numerical investigation was conducted on a four-stroke large marine diesel engine (ALCO 16V 251C) at several engine speeds and full load conditions. Different blends of diesel–methanol and biodiesel B20–methanol with methanol mass fractions of 10% and 20% were considered for theoretical analysis in two techniques of methanol supply: direct injection mode of a blend of base fuel diesel/biodiesel B20 with methanol and injection of methanol after the intercooler, and direct injection of the base fuel. The results show that, if 10% in power loss can be acceptable, then for diesel–methanol 10%, in the direct injection technology, the NOx emission can be reduced up to 19%, but with a compromise of an 8% increase in SOOT emission, while for biodiesel B20–methanol 10%, with the same direct injection method, the NOx emissions increase by up to 58% with the benefit of reducing SOOT by up to 23% relative to the original diesel fuel operation. For a 20% methanol fraction in blend fuel, the drop in power is more than 10% regardless of the method of methanol supply and the base fuel, diesel, or B20 used.

Die Corona-Pandemie führt zu zahlreichen Herausforderungen für Lehrkräfte und Schüler*innen. Die meist digital aufbereiteten Lernmaterialien sollten vor allem während des Lockdowns nur wenig Unterstützung seitens der Lehrkräfte erfordern und die Schüler*innen größtenteils zum selbstständigen Arbeiten befähigen. Dies bedeutete daher für die Lehrkräfte, möglichst binnendifferenzierendes Material zu entwickeln und digital umzusetzen, was z.T. ganz neue Ansätze erforderte. Auch für Eltern ergab sich durch das Homeschooling eine neue Situation, da sie die Rolle der Lehrkräfte zumindest in Teilen mitübernehmen und ihre Kinder beim Lernen zu Hause unterstützen müssen. In diesem Kontext ist davon auszugehen, dass Eltern durch diese zusätzliche Aufgabe neben ihrer eigenen Berufstätigkeit sowie angesichts nicht immer passgenauer Lernmaterialien für ihre Kinder eine Mehrbelastung erfahren. Dieser Beitrag geht der Thematik des Homeschoolings und der digital zur Verfügung gestellten Materialien nach und greift auf Ergebnisse einer Onlinebefragung von 635 Eltern in Rheinland-Pfalz zurück, die während der Schulschließung durchgeführt wurde. Dabei wird zum einen untersucht, wie das Belastungsempfinden der Eltern in dieser Zeit ausgeprägt ist und welche individuellen Faktoren dieses beeinflussen. Zum anderen wird analysiert, wie das Belastungsempfinden mit der Qualität der bereitgestellten Materialien und der eingeschätzten Medienkompetenz der Lehrkräfte zusammenhängt. Es zeigt sich, dass das Belastungserleben neben persönlichen Unterschieden auch durch die Gestaltung des Lehrmaterials beeinflusst wird.

The application of biological active preparations (BAPs) and remote-sensing control in the management of agronomic intervention are an important part of successful crop cultivation. The effects of foliar application of two BAPs (containing amino acids or Abiestins®) on yield and yield-forming, as well eco-physiological traits calculated from infrared thermographs data (crop water stress index, CWSI and index of stomatal conductance, Ig) of three hybrids of sunflower were studied in field poly-factorial experiments, realised during two years (2012 and 2013). The results showed that the application of selected BAPs has contributed to an increase of the sunflower yield, in particular through an increase in the weight of thousand seeds (rp = 0.761, P < 0.001). Similarly, oil content in achenes was significantly higher in treatments with BAPs, mainly with preparation containing free amino acids. The study describes the quantitative relationship between yield and quality of sunflower production (rp = −0.41, P < 0.01). Selected hybrids of sunflower in two growth stages showed the significant differences in CWSI and Ig (both at P < 0.01), respectively. An analysis of negative linear relation between the yield of achenes and CWSI (rp = −0.654, P < 0.001) confirmed that higher value of plant stress resulted in a smaller yield and vice-versa. The opposite trend was observed between yield and Ig index (rp = 0.576, P < 0.001). The data obtained from IR thermography can be used for monitoring the physiological health of sunflower plants, as well in potential prediction and control of yield.

Sexually dimorphic behaviour is pervasive across animals, with males and females exhibiting different mate selection, parental care, foraging, dispersal, and territorial strategies. However, the genetic underpinnings of sexually dimorphic behaviours are poorly understood. Here we investigate gene networks and expression patterns associated with sexually dimorphic imprinting-like learning in the butterfly Bicyclus anynana. In this species, both males and females learn visual preferences, but learn preferences for different traits and use different signals as salient, unconditioned cues. To identify genes and gene networks associated with this behaviour, we examined gene expression profiles of the brains and eyes of male and female butterflies immediately post training and compared them to the same tissues of naïve individuals. We found more differentially expressed genes and a greater number of associated gene networks in the eyes, indicating a role of the peripheral nervous system in visual imprinting-like learning. Females had higher chemoreceptor expression levels than males, supporting the hypothesized sexual dimorphic use of chemical cues during the learning process. In addition, genes that influence B. anynana wing patterns (sexual ornaments), such as invected, spalt, and apterous, were also differentially expressed in the brain and eye, suggesting that these genes may influence both sexual ornaments and the preferences for these ornaments. Our results indicate dynamic and sex-specific responses to social scenario in both the peripheral and central nervous systems and highlight the potential role of wing patterning genes in mate preference and learning across the Lepidoptera., (© 2023 John Wiley & Sons Ltd.)

Background: Animal behavior is largely driven by the information that animals are able to extract and process from their environment. However, the function and organization of sensory systems often change throughout ontogeny, particularly in animals that undergo indirect development. As an initial step toward investigating these ontogenetic changes at the molecular level, we characterized the sensory gene repertoire and examined the expression profiles of genes linked to vision and chemosensation in two life stages of an insect that goes through metamorphosis, the butterfly Bicyclus anynana., Results: Using RNA-seq, we compared gene expression in the heads of late fifth instar larvae and newly eclosed adults that were reared under identical conditions. Over 50 % of all expressed genes were differentially expressed between the two developmental stages, with 4,036 genes upregulated in larval heads and 4,348 genes upregulated in adult heads. In larvae, upregulated vision-related genes were biased toward those involved with eye development, while phototransduction genes dominated the vision genes that were upregulated in adults. Moreover, the majority of the chemosensory genes we identified in the B. anynana genome were differentially expressed between larvae and adults, several of which share homology with genes linked to pheromone detection, host plant recognition, and foraging in other species of Lepidoptera., Conclusions: These results revealed promising candidates for furthering our understanding of sensory processing and behavior in the disparate developmental stages of butterflies and other animals that undergo metamorphosis., (© 2021. The Author(s).)

Work-related musculoskeletal disorders occur frequently among the endoscopy staff, and patient-handling duties involved with colonoscopy-applying manual pressure and repositioning patients-are particularly physically demanding. This study explored whether the use of a lower abdominal compression device (ColoWrap), previously shown to reduce the need for manual pressure and patient repositioning, would diminish the frequency of staff-reported musculoskeletal pain. A randomized, blinded, sham-controlled clinical trial was performed at the University of North Carolina Hospitals. Three hundred fifty patients had either ColoWrap or a sham device applied before colonoscopy. The primary outcome was the frequency of staff-reported musculoskeletal pain after assisting with colonoscopy. In the intention-to-treat analysis, which included procedures in which ColoWrap was removed, there was no statistical difference in the frequency of staff-reported pain in the control versus ColoWrap arm (4.6% vs. 3.4% of procedures, p = .59). However, when ColoWrap was used as directed (e.g., remained in place for the duration of the procedure), the frequency of staff-reported musculoskeletal pain was significantly reduced (4.6% vs. 0.7% of procedures, p = 0.04). Use of ColoWrap as directed was also found to be independently associated with reduced odds of staff-reported pain relative to the sham arm (OR = 0.12; 95% CI [0.02, 0.95]). When used as directed, ColoWrap reduced the frequency of musculoskeletal pain experienced related to assisting with colonoscopy and may reduce the risk of musculoskeletal disorders and injuries among the endoscopy staff., Competing Interests: Conflicts of interest: Biggers—Employee of ColoWrap; Crockett—Research funding from ColoWrap (this study only), Boston Scientific, and Exact Sciences; and Dellon—Research funding from Meritage Pharma, and Miraca Life Sciences. Dr Ernst reports no conflicts of interest., (Copyright © 2021 The Authors. Published by Wolters Kluwer Health, Inc. on behalf of the Society of Gastroenterology Nurses and Associates.)

Diverse animals use Earth's magnetic field to guide their movements, but the neural and molecular mechanisms underlying the magnetic sense remain enigmatic. One hypothesis is that particles of the mineral magnetite (Fe 3 O 4 ) provide the basis of magnetoreception. Here we examined gene expression in the central nervous system of a magnetically sensitive invertebrate, the Caribbean spiny lobster (Panulirus argus), after applying a magnetic pulse known to alter magnetic orientation behavior. Numerous genes were differentially expressed in response to the pulse, including 647 in the brain, 1256 in the subesophageal ganglion, and 712 in the thoracic ganglia. Many such genes encode proteins linked to iron regulation, oxidative stress, and immune response, consistent with possible impacts of a magnetic pulse on magnetite-based magnetoreceptors. Additionally, however, altered expression also occurred for numerous genes with no apparent link to magnetoreception, including genes encoding proteins linked to photoreception, carbohydrate and hormone metabolism, and other physiological processes. Overall, the results are consistent with the magnetite hypothesis of magnetoreception, yet also reveal that in spiny lobsters, a strong pulse altered expression of > 10% of all expressed genes, including many seemingly unrelated to sensory processes. Thus, caution is required when interpreting the effects of magnetic pulses on animal behavior.

The ability to perceive the Earth's magnetic field, or magnetoreception, exists in numerous animals. Although the mechanism underlying magnetoreception has not been clearly established in any species, in salmonid fish, it is hypothesized to occur by means of crystals of magnetite associated with nervous tissue such as the brain, olfactory organ or retina. In this study, rainbow trout ( Oncorhynchus mykiss ) were exposed to a brief magnetic pulse known to disrupt magnetic orientation behaviour in several animals. Changes in gene expression induced by the pulse were then examined in the retina. Analyses indicated that the pulse elicited differential expression of only a single gene, gamma-crystallin M3-like ( crygm3 ). The near absence of an effect of the magnetic pulse on gene expression in the retina stands in sharp contrast to a recent study in which 181 genes were differentially expressed in brain tissue of O. mykiss after exposure to the same pulse. Overall, our results suggest either that magnetite-based magnetoreceptors in trout are not located in the retina, or else that they are unaffected by magnetic pulses that can disrupt magnetic orientation behaviour in animals., (© 2018 The Author(s).)

On a global scale, the geomagnetic field varies predictably across the Earth's surface, providing animals that migrate long distances with a reliable source of directional and positional information that can be used to guide their movements. In some locations, however, magnetic minerals in the Earth's crust generate an additional field that enhances or diminishes the overall field, resulting in unusually steep gradients of field intensity within a limited area. How animals respond to such magnetic anomalies is unclear. The Caribbean spiny lobster, Panulirus argus , is a benthic marine invertebrate that possesses a magnetic sense and is likely to encounter magnetic anomalies during migratory movements and homing. As a first step toward investigating whether such anomalies affect the behavior of lobsters, a two-choice preference experiment was conducted in which lobsters were allowed to select one of two artificial dens, one beneath a neodymium magnet and the other beneath a non-magnetic weight of similar size and mass (control). Significantly more lobsters selected the control den, demonstrating avoidance of the magnetic anomaly. In addition, lobster size was found to be a significant predictor of den choice: lobsters that selected the anomaly den were significantly smaller as a group than those that chose the control den. Taken together, these findings provide additional evidence for magnetoreception in spiny lobsters, raise the possibility of an ontogenetic shift in how lobsters respond to magnetic fields, and suggest that magnetic anomalies might influence lobster movement in the natural environment., Competing Interests: Competing interestsThe authors declare no competing or financial interests., (© 2018. Published by The Company of Biologists Ltd.)

Diverse animals use Earth's magnetic field in orientation and navigation, but little is known about the molecular mechanisms that underlie magnetoreception. Recent studies have focused on two possibilities: (i) magnetite-based receptors; and (ii) biochemical reactions involving radical pairs. We used RNA sequencing to examine gene expression in the brain of rainbow trout ( Oncorhynchus mykiss ) after exposure to a magnetic pulse known to disrupt magnetic orientation behaviour. We identified 181 differentially expressed genes, including increased expression of six copies of the frim gene, which encodes a subunit of the universal iron-binding and trafficking protein ferritin. Functions linked to the oxidative effects of free iron (e.g. oxidoreductase activity, transition metal ion binding, mitochondrial oxidative phosphorylation) were also affected. These results are consistent with the hypothesis that a magnetic pulse alters or damages magnetite-based receptors and/or other iron-containing structures, which are subsequently repaired or replaced through processes involving ferritin. Additionally, some genes that function in the development and repair of photoreceptive structures (e.g. crggm3 , purp , prl , gcip , crabp1 and pax6 ) were also differentially expressed, raising the possibility that a magnetic pulse might affect structures and processes unrelated to magnetite-based magnetoreceptors., (© 2017 The Author(s).)

The Caribbean spiny lobster, Panulirus argus, is a migratory crustacean that uses Earth's magnetic field as a navigational cue, but how these lobsters detect magnetic fields is not known. Magnetic material thought to be magnetite has previously been detected in spiny lobsters, but its role in magnetoreception, if any, remains unclear. As a first step toward investigating whether lobsters might have magnetite-based magnetoreceptors, we subjected lobsters to strong, pulsed magnetic fields capable of reversing the magnetic dipole moment of biogenic magnetite crystals. Lobsters were subjected to a single pulse directed from posterior to anterior and either: (1) parallel to the horizontal component of the geomagnetic field (i.e. toward magnetic north); or (2) antiparallel to the horizontal field (i.e. toward magnetic south). An additional control group was handled but not subjected to a magnetic pulse. After treatment, each lobster was tethered in a water-filled arena located within 200 m of the capture location and allowed to walk in any direction. Control lobsters walked in seemingly random directions and were not significantly oriented as a group. In contrast, the two groups exposed to pulsed fields were significantly oriented in approximately opposite directions. Lobsters subjected to a magnetic pulse applied parallel to the geomagnetic horizontal component walked westward; those subjected to a pulse directed antiparallel to the geomagnetic horizontal component oriented approximately northeast. The finding that a magnetic pulse alters subsequent orientation behavior is consistent with the hypothesis that magnetoreception in spiny lobsters is based at least partly on magnetite-based magnetoreceptors., (© 2016. Published by The Company of Biologists Ltd.)

Sea turtles are capable of navigating across large expanses of ocean to arrive at remote islands for nesting, but how they do so has remained enigmatic. An interesting example involves green turtles (Chelonia mydas) that nest on Ascension Island, a tiny land mass located approximately 2000 km from the turtles' foraging grounds along the coast of Brazil. Sensory cues that turtles are known to detect, and which might hypothetically be used to help locate Ascension Island, include the geomagnetic field, airborne odorants, and waterborne odorants. One possibility is that turtles use magnetic cues to arrive in the vicinity of the island, then use chemical cues to pinpoint its location. As a first step toward investigating this hypothesis, we used oceanic, atmospheric, and geomagnetic models to assess whether magnetic and chemical cues might plausibly be used by turtles to locate Ascension Island. Results suggest that waterborne and airborne odorants alone are insufficient to guide turtles from Brazil to Ascension, but might permit localization of the island once turtles arrive in its vicinity. By contrast, magnetic cues might lead turtles into the vicinity of the island, but would not typically permit its localization because the field shifts gradually over time. Simulations reveal, however, that the sequential use of magnetic and chemical cues can potentially provide a robust navigational strategy for locating Ascension Island. Specifically, one strategy that appears viable is following a magnetic isoline into the vicinity of Ascension Island until an odor plume emanating from the island is encountered, after which turtles might either: (1) initiate a search strategy; or (2) follow the plume to its island source. These findings are consistent with the hypothesis that sea turtles, and perhaps other marine animals, use a multi-modal navigational strategy for locating remote islands.