bluuebunny/crossref_metadata_2025 huggingface dataset:
Endovascular Hepatic Artery Stents in the Modern Management of Postpancreatectomy Hemorrhage
Authors: Finch Louise M. , Baltatzis Minas , Byott Sam , Ganapathy Anantha-Krishnan , Kakani Nirmal , Lake Edward , Cadwallader Rosemary , Hazar Can , Seriki Dare , Butterfield Stephen , Jegatheeswaran Santhalingam , Jamdar Saurabh , de Liguori Carino Nicola , Siriwardena Ajith K.
Published: February 2021

Background:

Postoperative hemorrhage is a potentially lethal complication of pancreatoduodenectomy. This study reports on the use of endovascular hepatic artery stents in the management of postpancreatectomy hemorrhage.

Methods:

This is a retrospective analysis of a prospectively maintained, consecutive dataset of 440 patients undergoing pancreatoduodenectomy over 68 months. Data are presented on bleeding events and outcomes, and contextualized by the clinical course of the denominator population. International Study Group of Pancreatic Surgery terminology was used to define postpancreatectomy hemorrhage.

Results:

Sixty-seven (15%) had postoperative hemorrhage. Fifty (75%) were male and this gender difference was significant (P = 0.001; 2 proportions test). Postoperative pancreatic fistulas were more frequent in the postoperative hemorrhage group (P = 0.029; 2 proportions test). The median (interquartile range [IQR]) delay between surgery and postoperative hemorrhage was 5 days (2–14 days). Twenty-six (39%) required intervention comprising reoperation alone in 12, embolization alone in 5, and endovascular hepatic artery stent deployment in 5. Four further patients underwent more than 1 intervention with 2 of these having stents. Endovascular stent placement achieved initial hemostasis in 5 of 7 (72%). Follow-up was for a median (IQR) of 199 days (145–400 days) poststent placement. In 2 patients, the stent remained patent at last follow-up. The remaining 5 stents occluded with a median (IQR) period of proven patency of 10 days (8–22 days).

Conclusions:

This study shows that in the specific setting of postpancreatoduodenectomy hemorrhage with either a short remnant gastroduodenal artery bleed or a direct bleed from the hepatic artery, where embolization risks occlusion with compromise of liver arterial inflow, endovascular hepatic artery stent is an important hemostatic option but is associated with a high risk of subsequent graft occlusion.
Impact of Preoperative Malnutrition on Postoperative Long-Term Outcomes of Patients With Pancreatic Head Cancer
Authors: Lee Boram , Han Ho-Seong , Yoon Yoo-Seok
Published: February 2021

Objective:

To evaluate the association between preoperative malnutrition and long-term outcomes in patients with pancreatic head cancer who underwent curative pancreatoduodenectomy (PD).

Methods:

From 2004 to 2018, 228 consecutive patients who underwent curative PD for pancreatic ductal adenocarcinoma were included. Preoperative malnutrition was defined by the Global Leadership Initiative in Malnutrition criteria. It is based on both phenotypic criteria (weight loss, low body mass index, and reduced muscle mass) and etiologic criteria (reduced intake or assimilation and inflammation).

Results:

Seventy-five (32.9%) of 228 patients were classified as suffering from malnutrition. Preoperative malnutrition was associated with an increased risk of estimated blood loss (mL) (816.7 ± 875.2 vs 593.1 ± 489.9, P = 0.015) and longer hospital stay (days) (27.3 ± 15.7 vs 22.9 ± 17.7, P = 0.045). The median follow-up period was 24.5 months. The malnutrition group had poor overall survival compared with “without (WO)-malnutrition” group (P = 0.001) at 1 year (66.3% vs 81.3%), 3 years (18.0% vs 51.8%), and 5 years (12.0% vs 39.3%). The malnutrition group showed poor disease-free survival and cancer-specific survival compared with WO-malnutrition group (P = 0.001) at 1 year (38.9% vs 66.7%) and (69.0% vs 88.7%), 3 years (11.5% vs 45.1%) and (21.1% vs 61.6%), and 5 years (11.5% vs 37.3%) and (14.1% vs 51.2%). In multivariate analysis, the preoperative malnutrition was found to be the predictor of poor prognosis (harzard ratio = 2.29, 95% confidence interval = 1.60–3.29, P = 0.001).

Conclusions:

Preoperative malnutrition is associated with poor prognosis in patients who underwent curative PD for pancreatic head cancer.
Hemophilia Gene Therapy: Approaching the First Licensed Product
Authors: Batty Paul , Lillicrap David
Published: February 2021

The clinical potential of hemophilia gene therapy has now been pursued for the past 30 years, and there is a realistic expectation that this goal will be achieved within the next couple of years with the licensing of a gene therapy product. While recent late phase clinical trials of hemophilia gene therapy have shown promising results, there remain a number of issues that require further attention with regard to both efficacy and safety of this therapeutic approach. In this review, we present information relating to the current status of the field and focus attention on the unanswered questions for hemophilia gene therapy and the future challenges that need to be overcome to enable the widespread application of this treatment paradigm.
Experiences of involuntary job loss and health during the economic crisis in Portugal
Authors: Macassa Gloria , Rodrigues Carina , Barros Henrique , Marttila Anneli
Published: February 2021

Background:

The economic recession that started in 2008 left many unemployed across several European countries. Many studies have analyzed the relationship between job loss, health, and well-being in other contexts. This study aimed to explore experiences of involuntary unemployment during the economic recession and their relationship with health, conceptualized as a state of physical, mental, and social well-being among unemployed individuals.

Methods:

Semistructured qualitative interviews were carried out among a convenience sample of participants who became unemployed during the economic recession. The analysis was conducted to identify patterns and themes.

Results:

Participants (n = 22; 8 men and 14 women; 23–51 years) experienced feelings of loss of identity, stress, and a sense of powerlessness due to unemployment, as well as a lack of purpose and structure in their daily lives. Six themes were identified: work as the basis for life structure and personal fulfillment; response to unemployment and the importance of its duration; unemployment leading to isolation and loss of a role in society; impact of a change in financial situation on social life and consumption patterns; the physical and psychological health consequences of unemployment; and searching for ways to cope with unemployment and to feel well.

Conclusions:

Losing a job is an adverse experience that impairs an individual's perception of overall health and well-being. From a public health perspective, the results of this study highlight the need for policymakers’ awareness to help mitigate the potential consequences of involuntary job loss in the short- and long-term.
The spatial network of skeletal proteins in a stony coral
Authors: Mummadisetti Manjula P. , Drake Jeana L. , Falkowski Paul G.
Published: February 2021

Coral skeletons are materials composed of inorganic aragonitic fibres and organic molecules including proteins, sugars and lipids that are highly organized to form a solid biomaterial upon which the animals live. The skeleton contains tens of proteins, all of which are encoded in the animal genome and secreted during the biomineralization process. While recent advances are revealing the functions and evolutionary history of some of these proteins, how they are spatially arranged in the skeleton is unknown. Using a combination of chemical cross-linking and high-resolution tandem mass spectrometry, we identify, for the first time, the spatial interactions of the proteins embedded within the skeleton of the stony coralStylophora pistillata. Our subsequent network analysis revealed that several coral acid-rich proteins are invariably associated with carbonic anhydrase(s), alpha-collagen, cadherins and other calcium-binding proteins. These spatial arrangements clearly show that protein–protein interactions in coral skeletons are highly coordinated and are key to understanding the formation and persistence of coral skeletons through time.
The effect of external flow on the feeding currents of sessile microorganisms
Authors: Pepper Rachel E. , Riley Emily E. , Baron Matthieu , Hurot Thomas , Nielsen Lasse Tor , Koehl M. A. R. , Kiørboe Thomas , Andersen Anders
Published: February 2021

Microscopic sessile suspension feeders live attached to surfaces and, by consuming bacteria-sized prey and by being consumed, they form an important part of aquatic ecosystems. Their environmental impact is mediated by their feeding rate, which depends on a self-generated feeding current. The feeding rate has been hypothesized to be limited by recirculating eddies that cause the organisms to feed from water that is depleted of food particles. However, those results considered organisms in still water, while ambient flow is often present in their natural habitats. We show, using a point-force model, that even very slow ambient flow, with speed several orders of magnitude less than that of the self-generated feeding current, is sufficient to disrupt the eddies around perpendicular suspension feeders, providing a constant supply of food-rich water. However, the feeding rate decreases in external flow at a range of non-perpendicular orientations due to the formation of recirculation structures not seen in still water. We quantify the feeding flow and observe such recirculation experimentally for the suspension feeder
Vorticella convallaria
in external flows typical of streams and rivers.
Rapid synthesis and characterization of silver-loaded graphene oxide nanomaterials and their antibacterial applications
Authors: Zhu Jiang , Ni Haitao , Hu Chunyan , Zhu Yuxiang , Cai Jinxia , Liu Song , Gao Jie , Yang Heshan , Liu Hongpan
Published: February 2021

With the promising potential application of Ag/graphene-based nanomaterials in medicine and engineering materials, the large-scale production has attracted great interest of researchers on the basis of green synthesis. In this study, water-soluble silver/graphene oxide (Ag/GO) nanomaterials were synthesized under ultrasound-assisted conditions. The structural characteristics of Ag/GO were confirmed by Fourier transform infrared spectroscopy, X-ray diffraction, transmission electron microscopy, scanning electron microscopy and energy dispersion spectroscopy, respectively. The results showed the silver particles (AgNPs) obtained by reduction were attached to the surface of GO, and there was a strong interaction between AgNPs and GO. The antibacterial activity was primarily evaluated by the plate method and hole punching method. Antibacterial tests indicated that Ag/GO could inhibit the growth of Gram-negative and Gram-positive bacteria, special for the
Staphylococcus aureus
.
Creation of a peptide database of corneous beta-proteins of marine turtles for the identification of tortoiseshell: archaeological combs as case study
Authors: Solazzo Caroline , Soulat Jean , Cleland Timothy
Published: February 2021

Tortoiseshell is a proteinaceous material derived from the scutes of marine turtles, and was shaped into an abundance of objects, especially luxurious items, at its peak in the seventeenth and eighteenth century. It has continued to be used even after the advent of plastics and remains one of the main causes of illegal poaching of marine turtles, in particular the hawksbill turtleEretmochelys imbricata. Tortoiseshell is made of structural proteins, of which the most abundant are known as β-keratins, or ‘corneous beta-proteins' (CBPs), a family of short proteins containing a central structure in β-sheets. There are, however, few CBP sequences of marine turtles in protein databases. The scutes of the five main species of marine turtles (Chelonia mydas,Caretta caretta, Eretmochelys imbricata,Lepidochelys olivaceaandLepidochelys kempii) were analysed by proteomics, using nano-liquid chromatography-Orbitrap-mass spectrometry to generate peptidic markers for species identification. A total of 187 marker sequences were identified, the large majority of them obtained from automated de novo sequencing. The sequences were classified into peptides A to F: A to D at the N-terminus and central region that forms the β-pleated sheets, E1–4 for a variable region of glycine-repeats region and F at the C-terminus. The markers were tested against a set of combs discovered in various archaeological sites of modern period in France, successfully identifying hawksbill turtle and highlighting patterns of degradation in archaeological tortoiseshell.
U(VI) adsorption in water by sodium alginate modified
Bacillus megaterium
Authors: Li Dianxin , Yang Yiqing , Zhang Peng , Liu Jiangang , Li Tao , Yang Junwei
Published: February 2021

The surface of
Bacillus megaterium
was modified by coating sodium alginate. The modified
B. megaterium
before and after adsorption were characterized by SEM, FTIR and XPS. The effects of pH, reaction time, initial U(VI) concentration and adsorbent dosage on the adsorption of U(VI) by the modified
B. megaterium
were studied by batch adsorption experiments. The adsorption process was studied by pseudo-first-order kinetics and pseudo-second-order kinetic models, Langmuir and Freundlich isotherms. The results showed that the maximum adsorption capacity of U(VI) was 74.61 mg g
−1
under the conditions of pH 5.0, adsorbent 0.2 g l
−1
, 30°C and initial U(VI) concentration of 15 mg l
−1
. The adsorption process accords with pseudo-first-order kinetics and Langmuir isotherm. The adsorption capacity of U(VI) by the modified
B. megaterium
was still higher than 80% after five times of desorption and reuse experiments. In conclusion, the sodium alginate modified
B. megaterium
was an ideal material for U(VI) biosorption.
Earliest Palaeocene purgatoriids and the initial radiation of stem primates
Authors: Wilson Mantilla Gregory P. , Chester Stephen G. B. , Clemens William A. , Moore Jason R. , Sprain Courtney J. , Hovatter Brody T. , Mitchell William S. , Mans Wade W. , Mundil Roland , Renne Paul R.
Published: February 2021

Plesiadapiform mammals, as stem primates, are key to understanding the evolutionary and ecological origins of Pan-Primates and Euarchonta. The Purgatoriidae, as the geologically oldest and most primitive known plesiadapiforms and one of the oldest known placental groups, are also central to the evolutionary radiation of placentals and the Cretaceous-Palaeogene biotic recovery on land. Here, we report new dental fossils of
Purgatorius
from early Palaeocene (early Puercan) age deposits in northeastern Montana that represent the earliest dated occurrences of plesiadapiforms. We constrain the age of these earliest purgatoriids to magnetochron C29R and most likely to within 105–139 thousand years post-K/Pg boundary. Given the occurrence of at least two species,
Purgatorius janisae
and a new species, at the locality, we provide the strongest support to date that purgatoriids and, by extension, Pan-Primates, Euarchonta and Placentalia probably originated by the Late Cretaceous. Within 1 million years of their arrival in northeastern Montana, plesiadapiforms outstripped archaic ungulates in numerical abundance and dominated the arboreal omnivore–frugivore niche in mammalian local faunas.
Positive selection and gene duplications in tumour suppressor genes reveal clues about how cetaceans resist cancer
Authors: Tejada-Martinez Daniela , de Magalhães João Pedro , Opazo Juan C.
Published: February 2021

Cetaceans are the longest-living species of mammals and the largest in the history of the planet. They have developed mechanisms against diseases such cancer, although the underlying molecular bases of these remain unknown. The goal of this study was to investigate the role of natural selection in the evolution of 1077 tumour suppressor genes (TSGs) in cetaceans. We used a comparative genomic approach to analyse two sources of molecular variation in the form ofdN/dSrates and gene copy number variation. We found a signal of positive selection in the ancestor of cetaceans within theCXCR2gene, an important regulator of DNA damage, tumour dissemination and immune system. Further, in the ancestor of baleen whales, we found six genes exhibiting positive selection relating to diseases such as breast carcinoma, lung neoplasm (ADAMTS8) and leukaemia (ANXA1). The TSGs turnover rate (gene gain and loss) was almost 2.4-fold higher in cetaceans when compared with other mammals, and notably even faster in baleen whales. The molecular variants in TSGs found in baleen whales, combined with the faster gene turnover rate, could have favoured the evolution of their particular traits of anti-cancer resistance, gigantism and longevity. Additionally, we report 71 genes with duplications, of which 11 genes are linked to longevity (e.g.NOTCH3andSIK1) and are important regulators of senescence, cell proliferation and metabolism. Overall, these results provide evolutionary evidence that natural selection in TSGs could act on species with large body sizes and extended lifespan, providing novel insights into the genetic basis of disease resistance.
Developmental processes in Ediacara macrofossils
Authors: Evans Scott D. , Droser Mary L. , Erwin Douglas H.
Published: February 2021

The Ediacara Biota preserves the oldest fossil evidence of abundant, complex metazoans. Despite their significance, assigning individual taxa to specific phylogenetic groups has proved problematic. To better understand these forms, we identify developmentally controlled characters in representative taxa from the Ediacaran White Sea assemblage and compare them with the regulatory tools underlying similar traits in modern organisms. This analysis demonstrates that the genetic pathways for multicellularity, axial polarity, musculature, and a nervous system were likely present in some of these early animals. Equally meaningful is the absence of evidence for major differentiation of macroscopic body units, including distinct organs, localized sensory machinery or appendages. Together these traits help to better constrain the phylogenetic position of several key Ediacara taxa and inform our views of early metazoan evolution. An apparent lack of heads with concentrated sensory machinery or ventral nerve cords in such taxa supports the hypothesis that these evolved independently in disparate bilaterian clades.
An early dog from southeast Alaska supports a coastal route for the first dog migration into the Americas
Authors: da Silva Coelho Flavio Augusto , Gill Stephanie , Tomlin Crystal M. , Heaton Timothy H. , Lindqvist Charlotte
Published: February 2021

The oldest confirmed remains of domestic dogs in North America are from mid-continent archaeological sites dated approximately 9900 calibrated years before present (cal BP). Although this date suggests that dogs may not have arrived alongside the first Native Americans, the timing and routes for the entrance of New World dogs remain uncertain. Here, we present a complete mitochondrial genome of a dog from southeast Alaska, dated to 10 150 ± 260 cal BP. We compared this high-coverage genome with data from modern dog breeds, historical Arctic dogs and American precontact dogs (PCDs) from before European arrival. Our analyses demonstrate that the ancient dog belongs to the PCD lineage, which diverged from Siberian dogs around 16 700 years ago. This timing roughly coincides with the minimum suggested date for the opening of the North Pacific coastal (NPC) route along the Cordilleran Ice Sheet and genetic evidence for the initial peopling of the Americas. This ancient southeast Alaskan dog occupies an early branching position within the PCD clade, indicating it represents a close relative of the earliest PCDs that were brought alongside people migrating from eastern Beringia southward along the NPC to the rest of the Americas. The stable isotopeδ13C value of this early dog indicates a marine diet, different from the younger mid-continent PCDs' terrestrial diet. Although PCDs were largely replaced by modern European dog breeds, our results indicate that their population decline started approximately 2000 years BP, coinciding with the expansion of Inuit peoples, who are associated with traditional sled-dog culture. Our findings suggest that dogs formed part of the initial human habitation of the New World, and provide insights into their replacement by both Arctic and European lineages.
Maximum CO2diffusion inside leaves is limited by the scaling of cell size and genome size
Authors: Théroux-Rancourt Guillaume , Roddy Adam B. , Earles J. Mason , Gilbert Matthew E. , Zwieniecki Maciej A. , Boyce C. Kevin , Tholen Danny , McElrone Andrew J. , Simonin Kevin A. , Brodersen Craig R.
Published: February 2021

Maintaining high rates of photosynthesis in leaves requires efficient movement of CO2from the atmosphere to the mesophyll cells inside the leaf where CO2is converted into sugar. CO2diffusion inside the leaf depends directly on the structure of the mesophyll cells and their surrounding airspace, which have been difficult to characterize because of their inherently three-dimensional organization. Yet faster CO2diffusion inside the leaf was probably critical in elevating rates of photosynthesis that occurred among angiosperm lineages. Here we characterize the three-dimensional surface area of the leaf mesophyll across vascular plants. We show that genome size determines the sizes and packing densities of cells in all leaf tissues and that smaller cells enable more mesophyll surface area to be packed into the leaf volume, facilitating higher CO2diffusion. Measurements and modelling revealed that the spongy mesophyll layer better facilitates gaseous phase diffusion while the palisade mesophyll layer better facilitates liquid-phase diffusion. Our results demonstrate that genome downsizing among the angiosperms was critical to restructuring the entire pathway of CO2diffusion into and through the leaf, maintaining high rates of CO2supply to the leaf mesophyll despite declining atmospheric CO2levels during the Cretaceous.
Transcriptome of Cydia pomonella granulovirus in susceptible and type I resistant codling moth larvae
Authors: Wennmann Jörg T. , Pietruska Diana , Jehle Johannes A.
Published: February 2021

The baculovirus Cydia pomonella granulovirus (CpGV) is a biocontrol agent used worldwide against the codling moth (CM), Cydia pomonella L., a severe pest in organic and integrated pome fruit production. Its successful application is increasingly challenged by the occurrence of CM populations resistant to commercial CpGV products. Whereas three types (I–III) of CpGV resistance have been identified, type I resistance compromising the efficacy of CpGV-M, the so-called Mexican isolate of CpGV, is assumed to be the most widely distributed resistance type in Central Europe. Despite the wide use of CpGV products as biocontrol agents, little information is available on gene-expression levels in CM larvae. In this study, the in vivo transcriptome of CpGV-M infecting susceptible (CpS) and resistant (CpRR1) CM larvae was analysed at 24, 48, 72, 96 and 120 hours post infection in the midgut and fat body tissue by using a newly developed microarray covering all ORFs of the CpGV genome. According to their transcript abundance, the CpGV genes were grouped into four temporal clusters to which groups of known and unknown function could be assigned. In addition, sets of genes differentially expressed in the midgut and fat body were found in infected susceptible CpS larvae. For the resistant CpRR1 larvae treated with CpGV-M, viral entry in midgut cells could be confirmed from onset but a significantly reduced gene expression, indicating that type I resistance is associated with a block of viral gene transcription and replication.
The simple direct slide method is comparable to indirect Lowenstein Jensen proportion culture for detecting rifampicin resistant tuberculosis
Authors: Achan Beatrice , Asiimwe Benon B. , Joloba Moses L. , Gumusboga Mourad , Ssengooba Willy , Bwanga Freddie
Published: February 2021

Introduction. Drug resistant tuberculosis remains a worldwide problem that requires prompt diagnosis.

Hypothesis/Gap statement. The WHO recommended direct, rapid Xpert MTB/RIF is prohibitively costly, therefore, there is a need to validate a rapid, affordable DST for use in low- and middle-income settings.

Aim. The technical performance and time to results of a simple, direct microscopy-based slide DST (SDST) assay for diagnosis of rifampicin-resistant TB was evaluated in Uganda.

Methodology. Sputum samples from 122 smear-positive re-treatment TB patients presenting to the TB treatment centre at Uganda’s National Referral Hospital, Mulago, Kampala, Uganda were examined. The sputum samples were tested by the direct SDST which was compared to the indirect Lowenstein Jensen Proportion Method (LJDST) method as the gold standard. The time to results was defined as the time from DST setting to results interpretation. The results were further analysed for sensitivity and specificity as well as agreement between LJDST and SDST for rifampicin resistance determination.

Results. A total of 117 smear positive sputum samples with valid results for both tests were compared. The median time to results for SDST was 14 days with an interquartile range (IQR) of 10–14 days compared to 60 days with IQR of 60–75 days for LJDST. The number for rifampicin resistance by the gold standard LJDST was 26. The SDST had a sensitivity of 96 % (95 %; CI 81–99 %) and a specificity of 97.8 % (95 %; CI 93–100 %). The Positive Predictive and Negative Predictive values for SDST were 92.3 % (95 %; CI 76.8–99 %) and 98.9 % (95 %; CI 94–100 %), respectively. The kappa agreement between SDST and LJDST was 92.3 %.

Conclusion. The SDST was found to be a rapid and accurate direct test for the detection of rifampicin resistance among retreatment TB cases in low-income settings.
Do epigenetic clocks provide explanations for sex differences in lifespan? A cross-sectional twin study
Authors: Kankaanpää Anna , Tolvanen Asko , Saikkonen Pirkko , Heikkinen Aino , Laakkonen Eija K. , Kaprio Jaakko , Ollikainen Miina , Sillanpää Elina
Published: February 2021

Background

The sex gap in life expectancy has been narrowing in Finland over the past four to five decades; however, on average, women still live longer than men. Epigenetic clocks are markers for biological aging that predict lifespan. In this study, we examined the mediating role of lifestyle factors on the association between sex and biological aging in younger and older adults.

Methods

Our sample included same-sex younger and older twins (21-42-y, n = 1110; 50-76-y, n = 763) and younger opposite-sex twins (21-30-y, n = 302). Blood-based DNA methylation (DNAm) was used to compute epigenetic age acceleration by four epigenetic clocks as a measure of biological aging. Path modelling was used to study whether the association between sex and biological aging is mediated through lifestyle-related factors, i.e. education, body mass index, smoking, alcohol use, and physical activity.

Findings

In comparison to women, men were biologically older and, in general, they had unhealthier life habits. The effect of sex on biological aging was partly mediated by smoking, but only in older twins. Sex was directly associated with biological aging and the association was stronger in older twins.

Interpretation

Previously reported sex differences in lifespan are also evident in biological aging. Declining smoking prevalence among men is a plausible explanation for the narrowing of the difference in life expectancy between the sexes. Data generated by the epigenetic clocks may help in estimating the effects of lifestyle and environmental factors on aging and in predicting aging in future generations.
Characterization of the different behaviours exhibited by juvenile grey mullet (Mugil cephalus) under rearing conditions
Authors: Jimenez-Rivera Jessica A. , Boglino Anaïs , Linares-Cordova Joel F. , Duncan Neil J. , de Lourdes Ruiz-Gómez María , Planellas Sonia Rey , Ibarra-Zatarain Zohar
Published: February 2021

This research described the common behaviour of grey mullet (Mugil cephalus) under rearing conditions. The different behaviours exhibited by mullets were videorecorded with submersible cameras installed inside of three tanks. A total of 690 minutes per day (07:30 - 18:30 hours) were recorded per tank during a week. Afterwards, an ethogram was elaborated to organize the different behaviours exhibited by juvenileM. cephalus, with two general categories: a) locomotion, including three different observed behaviours (resting, swimming and fast swimming) b) feeding, including three behaviours (surface feeding, bottom feeding and rubbing). The video recordings showed thatM. cephalusis a species with a constant locomotion associated to feeding, since they showed constantly movement during most of day light period the opposite to dark periods. Mullets were observed to be a non-aggressive fish species, due to the absence of dominance and aggression towards conspecifics, resulting in a high predisposition for adaptation to captivity. Finally, behavioural frequencies of grey mullet’s juveniles were not significantly different among the three tanks for most of the behavioural variables analysed (p>0.05) except for the variable bottom feeding (p=0.02). Results from this study could be of interest to the aquaculture industry to implement protocols and to optimize rearing techniques for the production of grey mullet.
The nanoscale organization of the Wnt signaling integrator Dishevelled in the development-essential vegetal cortex domain of an egg and early embryo
Authors: Henson John H. , Samasa Bakary , Shuster Charles B. , Wikramanayake Athula H.
Published: February 2021

Wnt/β-catenin (cWnt) signaling is a crucial regulator of development and Dishevelled (Dsh/Dvl) functions as an integral part of this pathway by linking Wnt binding to the frizzled:LRP5/6 receptor complex with β-catenin-stimulated gene expression. In many cell types Dsh has been localized to ill-defined cytoplasmic puncta, however in sea urchin eggs and embryos confocal fluorescence microscopy has shown that Dsh is localized to puncta present in a novel and development-essential vegetal cortex domain (VCD). In the present study, we used super-resolution light microscopy and platinum replica TEM to provide the first views of the ultrastructural organization of Dsh within the sea urchin VCD. 3D-SIM imaging of isolated egg cortices demonstrated the concentration gradient-like distribution of Dsh in the VCD, whereas higher resolution STED imaging revealed that some individual Dsh puncta consisted of more than one fluorescent source. Platinum replica immuno-TEM localization showed that Dsh puncta on the cytoplasmic face of the plasma membrane consisted of aggregates of pedestal-like structures each individually labeled with the C-terminus specific Dsh antibody. These aggregates were resistant to detergent extraction and treatment with drugs that disrupt actin filaments or inhibit myosin II contraction, and coexisted with the first division actomyosin contractile ring. These results confirm and extend previous studies and reveal, for the first time in any cell type, the nanoscale organization of plasma membrane tethered Dsh. Our current working hypothesis is that these Dsh pedestals represent a prepositioned scaffold organization that is important for canonical Wnt pathway activation at the sea urchin vegetal organization and may also be relevant to the submembranous Dsh puncta present in other eggs and embryos.
Increased biting rate and decreasedWolbachiadensity in irradiatedAedesmosquitoes
Authors: Moretti Riccardo , Lampazzi Elena , Damiani Claudia , Fabbri Giulia , Lombardi Giulia , Pioli Claudio , Desiderio Angiola , Serrao Aurelio , Calvitti Maurizio
Published: February 2021

Background

Releasing considerable numbers of radiation-sterilized males is a promising strategy to suppress mosquito vectors. However, releases may also include small percentages of biting females which translate to large numbers when releases are large. Currently, the effects of irradiation on the host-seeking and host-biting behaviors have not been exhaustively investigated. Information is also lacking regarding the effects of sterilizing treatment on the endosymbiotic bacteriumWolbachia, which is known to affect the vector competence of infected mosquitos.

Methods

To ascertain the effects of irradiation on females, the pupae of twoAedes albopictusstrains, differing in their natural or artificialWolbachiainfection type, andAe. aegypti—which is not infected byWolbachia—were treated with various doses of X-rays and monitored for key fitness parameters and biting behavior over a period of two weeks. The effect of radiation onWolbachiawas investigated by qPCR and FISH analysis.

Results

PartialAe. albopictusfemale sterility was achieved at 28 Gy but the number of weekly bites more than doubled compared to that of the controls. Radiation doses of 35 and 45 Gy completely inhibited progeny production but did not significantly affect the survival or flight ability ofAe. albopictusfemales and caused a tripling of the number of bites per female per week (compared to untreated controls). These results were also confirmed inAe. aegyptiafter treatment at 50 Gy.Wolbachiadensity decreased significantly in 45-Gray-irradiated females, with the greatest decreases in the early irradiation group (26±2-hour-old pupae).Wolbachiadensity also decreased as adults aged. This trend was confirmed in ovaries but not in extra-ovarian tissues. FISH analysis showed a strongly reducedWolbachia-specific fluorescence in the ovaries of 13±1-day-old females.

Conclusions

These results suggest that, under SIT programs, the vector capacity of a target population could increase with the frequency of the irradiated females co-released with the sterile males due to an increased biting rate. In the context of a successful suppression, the related safety issues could be generally negligible, but they should be conservatively evaluated when large scale programs relying on imperfect sexing and high overflooding release ratios are run for long time in areas endemic for arboviral diseases. Also, the effects of irradiation on the vector competence deserve further investigation.
Epitranscriptomic addition of m6A regulates HIV-1 RNA stability and alternative splicing
Authors: Tsai Kevin , Bogerd Hal P. , Kennedy Edward M. , Emery Ann , Swanstrom Ronald , Cullen Bryan R.
Published: February 2021

Previous work in several laboratories has demonstrated that the epitranscriptomic addition of m6A to viral transcripts promotes the replication and pathogenicity of a wide range of DNA and RNA viruses, yet the underlying mechanisms responsible for this positive effect have remained unclear. It is known that m6A function is largely mediated by cellular m6A binding proteins or readers, yet how m6A readers regulate viral gene expression in general, and HIV-1 gene expression in particular, has been controversial. Here, we confirm that m6A addition indeed regulates HIV-1 RNA expression and demonstrate that this effect is in large part mediated by the the nuclear m6A reader YTHDC1 and the cytoplasmic m6A reader YTHDF2. Both YTHDC1 and YTHDF2 bind to multiple distinct and overlapping sites on the HIV-1 RNA genome, with YTHDC1 recruitment serving to regulate the alternative splicing of HIV-1 RNAs while YTHDF2 binding correlates with increased HIV-1 transcript stability.

Author Summary

This manuscript reports that the expression of mRNAs encoded by the pathogenic human retrovirus HIV-1 is regulated by the methylation of a small number of specific adenosine residues. These in turn recruit a nuclear RNA binding protein, called YTHDC1, which modulates the alternative splicing of HIV-1 transcripts, as well as a cytoplasmic RNA binding protein, called YTHDF2, which stabilizes viral mRNAs. The regulation of HIV-1 gene expression by adenosine methylation is therefore critical for the effective and ordered expression of HIV-1 mRNAs and could represent a novel target for antiviral development.
INSULIN-LIKE GROWTH FACTOR I SENSITIZATION REJUVENATES SLEEP PATTERNS IN OLD MICE
Authors: Zegarra-Valdivia J.A. , Fernandes J. , Trueba-Saiz A. , de Sevilla M.E. Fernandez , Pignatelli J. , Suda K. , Martinez-Rachadell L. , Fernandez A.M. , Esparza J. , Vega M. , Nuñez A. , Aleman I. Torres
Published: February 2021

Sleep disturbances are common during aging. Compared to young animals, old mice show altered sleep structure, with changes in both slow and fast electrocorticographic (ECoG) activity and fewer transitions between sleep and wake stages. Insulin-like growth factor I (IGF-I), which is involved in adaptive changes during aging, was previously shown to increase ECoG activity in young mice and monkeys. Furthermore, IGF-I shapes sleep architecture by modulating the activity of mouse orexin neurons in the lateral hypothalamus (LH). We now report that both ECoG stimulation and activation of orexin neurons by systemic IGF-I is abrogated in old mice. Moreover, stimulation of orthodromically activated LH neurons by either systemic or local IGF-I in young mice is absent in old mice. As orexin neurons of old mice show markedly increased IGF-I receptor (IGF-IR) levels, suggesting loss of sensitivity to IGF-I, we treated old mice with AIK3a305, a novel IGF-IR sensitizer, and observed restored responses to IGF-I and rejuvenation of sleep patterns. Thus, disturbed sleep structure in aging mice may be related to impaired IGF-I signaling onto orexin neurons, reflecting a broader loss of IGF-I activity in the aged mouse brain.
Control of testes mass by androgen receptor paralogs in a cichlid
Authors: Hoadley Andrew P. , Fernald Russell D. , Alward Beau A.
Published: February 2021

Steroid hormones play numerous important and diverse roles in the differentiation and development of vertebrate primary and secondary reproductive characteristics. However, the exact role of androgen receptors (ARs)—which bind circulating androgens—in this regulatory pathway is unclear. Teleost fishes further complicate this question by having two paralogs of AR (ARα and ARβ) resulting from a duplication of their ancestral genome. We investigated the functional role of these two ARs on testes growth and development by experimentally eliminating receptor function of one or both paralogs using CRISPR/Cas9 genome editedAstatotilapia burtoni, an African cichlid fish. Fish with two or more functional receptor alleles were more likely to be male compared to fish with one or fewer, suggesting that the two paralogs of the receptor may be redundant in regulating early sex determination. In contrast, we found that adult testes size was significantly affected by distinct combinations of mutant and wild-type AR alleles. We present a working model whereby ARβ facilitates testes growth and ARα causes testes regression. This mechanism may contribute to the robust social and physiological plasticity displayed byA. burtoniand other social teleost fish.
Breeding responses to environmental variation are age- and trait-dependent in female Nazca boobies
Authors: Tompkins Emily M. , Anderson David J.
Published: February 2021

Age and environment are important determinants of reproductive parameters in long-lived organisms. These factors may interact to determine breeding responses to environmental change, yet few studies have examined the environmental-dependence of aging patterns across the entire lifespan. We do so, using a 20-year longitudinal dataset of reproductive phenotypes in long-lived female Nazca boobies (Sula granti), a monogamous seabird breeding in the eastern tropical Pacific. Young and old females may suffer from inexperience and senescence, respectively, and/or practice reproductive restraint. Breeding performance (for breeding participation, breeding date, clutch size, egg volume, and offspring production) was expected to be lower in these age classes, particularly under environmental challenge, in comparison with middle-aged breeders. Sea surface temperature anomalies (SSTA) represented interannual variation in the El Niño-Southern Oscillation (ENSO) and were one proxy for environmental quality (a population count of clutch initiations was a second). Although only females lay eggs, both sexes care for eggs and nestlings, and the male partner’s age, alone or in interaction with female age, was evaluated as a predictor of breeding performance. Middle-aged females performed better than young and old birds for all reproductive traits. Pairing with a young male delayed breeding (particularly for old females) and reduced clutch size, and pairing with an old male reduced offspring production. Challenging environments increased age effects on breeding probability and breeding date across young to middle ages and for offspring production across middle to old ages. However, important exceptions to the predicted patterns for clutch size and fledging success across young to middle ages suggested trade-offs between fitness components may complicate patterns of trait expression across the lifespan. Relationships between breeding participation, environment, and individual quality and/or experience in young females may also contribute to unexpected patterns for clutch size and fledging success, traits expressed only in breeders. Finally, independent of age, breeding responses of female Nazca boobies to the ENSO did not follow expectations derived from oceanic forcing of primary productivity. During El Niño-like conditions, egg-laying traits (clutch size, breeding date) improved but offspring production declined, while La Niña-like conditions were “poor” environments throughout the breeding cycle.
VALgenes regulate vegetative phase change via miR156-dependent and independent mechanisms
Authors: Fouracre Jim P. , He Jia , Chen Victoria J. , Sidoli Simone , Poethig R. Scott
Published: February 2021

How organisms control when to transition between different stages of development is a key question in biology. In plants, epigenetic silencing by Polycomb repressive complex 1 (PRC1) and PRC2 plays a crucial role in promoting developmental transitions, including from juvenile-to-adult phases of vegetative growth. PRC1/2 are known to repress the master regulator of vegetative phase change, miR156, leading to the transition to adult growth, but how this process is regulated temporally is unknown. Here we investigate whether transcription factors in theVIVIPAROUS/ABI3-LIKE(VAL) gene family provide the temporal signal for the epigenetic repression of miR156. Exploiting a novelval1allele, we found thatVAL1andVAL2redundantly regulate vegetative phase change by controlling the overall level, rather than temporal dynamics, of miR156 expression. Furthermore, we discovered thatVAL1andVAL2also act independently of miR156 to control this important developmental transition.
Topography and motion of the acid-sensing ion channel intracellular domains
Authors: Couch Tyler , Berger Kyle , Kneisley Dana L. , McCullock Tyler W. , J. Kammermeier Paul , MacLean David M.
Published: February 2021

Acid-sensing ion channels (ASICs) are trimeric cation-selective channels activated by decreases in extracellular pH. The intracellular N and C terminal tails of ASIC1 influence channel gating, trafficking, and signaling in ischemic cell death. Despite several x-ray and cryo-EM structures of the extracellular and transmembrane segments of ASIC1, these important intracellular tails remain unresolved. Here we describe the coarse topography of the cASIC1 intracellular domains determined by FRET, measured using either fluorescent lifetime imaging or patch clamp fluorometry. We find the C terminal tail projects into the cytosol by approximately 35 Å and that the N and proximal segment of the C tail from the same subunits are closer than adjacent subunits. Using pH-insensitive fluorescent proteins, we fail to detect any relative movement between the N and C tails upon extracellular acidification but do observe axial motions of the membrane proximal segments towards the plasma membrane. Taken together, our study furnishes a coarse topographic map of the ASIC intracellular domains while providing directionality and context to intracellular conformational changes induced by extracellular acidification.
Cardiac pathologies in mouse loss of imprinting models are due to misexpression of H19 long noncoding RNA
Authors: Park Ki-Sun , Rahat Beenish , Yu Zu-Xi , Noeker Jacob , Mitra Apratim , Knutsen Russell , Springer Danielle , Kozel Beth , Pfeifer Karl
Published: February 2021

Maternal loss of imprinting (LOI) at theH19/IGF2locus results in biallelicIGF2and reducedH19expression and is associated with Beckwith Wiedemann syndrome (BWS). We use mouse models for LOI to understand the relative importance ofIgf2andH19mis-expression in BWS phenotypes. Here we focus on cardiovascular phenotypes and show that neonatal cardiomegaly is exclusively dependent on increasedIgf2. Circulating IGF2 binds cardiomyocyte receptors to hyperactivate mTOR signaling, resulting in cellular hyperplasia and hypertrophy. TheseIgf2-dependent phenotypes are transient: cardiac size returns to normal onceIgf2expression is suppressed postnatally. However, reducedH19expression is sufficient to cause progressive heart pathologies including fibrosis and reduced ventricular function. In the heart,H19expression is concentrated predominantly in endothelial cells (ECs) and regulates EC differentiation both,in vivoandin vitro. Finally, we establish novel mouse models to show that cardiac phenotypes depend onH19lncRNA interactions withlet7microRNA.
Chronic Stress Alters Astrocyte Morphology in Mouse Prefrontal Cortex
Authors: Codeluppi Sierra A. , Chatterjee Dipashree , Prevot Thomas D. , Bansal Yashika , Misquitta Keith A. , Sibille Etienne , Banasr Mounira
Published: February 2021

Background

Neuromorphological changes are consistently reported in the prefrontal cortex (PFC) of patients with stress-related disorders and in rodent stress models, but the effects of stress on astrocyte morphology and potential link to behavioral deficits are relatively unknown.

Methods

To answer these questions, transgenic mice expressing green fluorescent protein (GFP) under the glial fibrillary acid protein (GFAP) promotor were subjected to 7, 21 or 35 days of chronic restraint stress (CRS). CRS induced behavioral effects on anhedonia- and anxiety-like behaviors were measured using the sucrose intake and the PhenoTyper tests, respectively. PFC GFP+ or GFAP+ cells morphology was assessed using Sholl analysis and associations with behavior were determined using correlation analysis.

Results

CRS-exposed male and female mice displayed anxiety-like behavior at 7, 21 and 35 days and anhedonia-like behavior at 35 days. Analysis of GFAP+ cell morphology revealed significant atrophy of distal processes following 21 and 35 days of CRS. CRS induced similar decreases in intersections at distal radii for GFP+ cells, accompanied by increased proximal processes. In males, the number of intersections at the most distal radius step significantly correlated with anhedonia-like behavior (r=0.622, p<0.05) for GFP+ cells and with behavioral emotionality calculated by z-scoring all behavioral measured deficits (r=-0.667, p<0.05). Similar but not significant correlations were observed in females. No correlation between GFP+ cell atrophy with anxiety-like behavior was found.

Conclusion

Chronic stress exposure induces a progressive atrophy of cortical astroglial cells, potentially contributing to maladaptive neuroplastic and behavioral changes associated with stress-related disorders.