bluuebunny/crossref_metadata_2025 huggingface dataset:
Relationship between extrinsic black stain and dental caries in a population of Argentina
Authors:   Universidad Nacional de Cordoba, Facultad Odontología, Gandolfo Mirta , Dario Arbelo ,   Universidad Nacional de Cordoba, Facultad Ciencias Médicas, Spadiliero-de-Lutri Mirta , Zarate Ana María
Published: July 2022

Many published studies express that the presence of extrinsic black stain on the enamel of tooth surfaces in children and adolescents is associated with less dental caries (CD) activity, this being valid for both primary and permanent dentition.The objective or this researh was to carry out a multifactorial approach to know the relationship between the presence of extrinsic black stain and the presence of caries, in a population of the city of Córdoba, Argentina.Methods. A case-control study (5: 1) was carried out in patients of both sexes from 3 to15 years of age, between the years 2016-2019, who were attended by spontaneous request to the Chair "A" of Pediatric Dentistry, of the Faculty of Dentistry, from the National University of Córdoba (n = 184). All patients underwent a Clinical History. Stimulated saliva was extracted for calcium and phosphate determination and dental biofilm was taken to measure CFU / mL of Streptococcus mutansand Lactobacillus spp.Results. The prevalence of extrinsic black spot was 1.78%. No significant association was found between sex, age and types of dentition between the groups studied. In the problem group, a lower amount of CFU / mL of S. mutans and Lactobacilluss pp was found, a higher concentration of calcium and phosphate and a lower caries index of the primary dentition. Patients with extrinsic black spot had a much lower rate.Conclusions. The extrinsic black spot could be an element of protection against caries, the recommendation for patients who present them would be to remove them from the visible areas and keep them in the rest of the dental elements
The student role for the return to attendance at the Faculty of Dentistry
Authors:   Universidad Nacional de Cordoba, Facultad de Odontología, Peralta de Elias Nicolas , De Leonardi Guillermo ,   Universidad Nacional de Cordoba, Facultad de Odontología, Mazzeo Marcelo ,   Universidad Nacional de Cordoba, Facultad de Odontología, Busleiman Federico ,   Universidad Nacional de Cordoba, Facultad de Odontología
Published: July 2022

The return to face-to-face post-quarantine in the Facultad de Odontología, Universidad Nacional de Córdoba was possible thanks to the participation of each of the members of your community pieces of a fundamental gear for the daily functioning of the institution. Student participation through volunteering alongside the program Compromiso Social Estudiantil, played a prominent role during the Sars Cov2 pandemic, for its collaboration with society in immunization campaigns, testing center and participation in logistics for the application of preventive measures in the Institution to prevent the spread of the virus
Experiences of the pandemic in dental students: application of a psycho-pedagogical questionnaire
Authors:   Universidad Nacional Cordoba, Facultad Odontología, Olmos MA
Published: July 2022

This work aims to investigate the effect of the pandemic as a psychosocial event in the lives of a group of dental students, inquiring about their opinion regarding of online teaching and learning, their study habits and lifestyle, during the lockdown for quarantine
Effect of Submergence on Transonic Flow Around a Hemisphere
Authors: Malkus Mikala J. , Frede Michael T. , Sherer Scott E. , Garmann Daniel J.
Published: July 2022

The effect of varying submergence on the transonic flow past canonical wall-mounted hemispheres is investigated at a freestream Mach number [Formula: see text] using delayed detached eddy simulations. Four submergence levels are considered, ranging from a full hemisphere (100% exposed) to a highly submerged case where the equator is well below the waterline (40% exposed). Analysis of the mean and unsteady features indicates that the shock foot and line of surface separation move downstream with submergence. However, the frequency associated with the streamwise motion of the shock remains consistent between the cases in terms of a suitably nondimensionalized Strouhal number [Formula: see text]. Proper orthogonal decomposition is used to isolate and rank the different modes; as the hemisphere is submerged, there is an evident change in prominence from the asymmetric “shifting” to the symmetric “breathing” mode. Dynamic mode decomposition was used to investigate the spectral content of these modes; the results show that the breathing mode collapses at a frequency of [Formula: see text] for all cases, while the shifting mode extends over a broad frequency range of [Formula: see text] between 0.13 and 0.21. Aero-optic analysis shows that the distortion for the more submerged hemisphere cases is associated primarily with the breathing mode, while for the fully exposed hemisphere the shifting mode is dominant.
Bullous pemphigoid in India: Review of cases registered in an autoimmune bullous disease clinic
Authors: De Dipankar , Kaushik Akanksha , Handa Sanjeev , Mahajan Rahul , Chatterjee Debajyoti , Saikia Biman , Saikia Uma Nahar , Radotra Bishan Dass , Minz Ranjana W
Published: July 2022

Background

Information on bullous pemphigoid in an Indian context is scarce.

Aim

To report clinico-demographic profile, associated comorbidities and prescription pattern of bullous pemphigoid patients in India.

Methods

This was a retrospective study, where past records of all bullous pemphigoid patients diagnosed and treated between November 2013 and October 2019 were accessed and analysed. Patients having a compatible clinical presentation with either histopathological and/or direct immunofluorescence evidence of bullous pemphigoid were included.

Results

There were 96 bullous pemphigoid patients, with a male: female ratio of 1.6:1. The mean age at diagnosis was 62.5 ± 2.2 years, with mean duration of illness 27.5 ± 4.5 months before presentation. Comorbidities were present in 80 (83%) patients, with type 2 diabetes mellitus (38.5%), hypertension (36.4%) and neurological illness (16.7%) being the commonest ones. Clinically, blisters were the predominant presentation in 81 (84.4%) patients. The majority (87.5%) of patients showed a predominant eosinophilic infiltrate on histopathology. Direct immunofluorescence revealed immunoglobulin G deposits with complement C3 in 77 (80.2%) cases. The majority of patients (77.1%) were treated with oral prednisolone, either alone (11.5%) or in combination (65.6%) with other topical and systemic agents. Topical steroids were used in 29.1%, azathioprine in 28%, dapsone in 16.7% and omalizumab in 6.2% of patients.

Limitations

The study is retrospective. Immunofluorescence on salt split skin, direct immunofluorescence serration pattern analysis, and immunoblotting were not performed. Hence, there is a possibility that a few included cases were suffering from other subepidermal autoimmune bullous diseases like epidermolysis bullosa acquisita or anti-p200 pemphigoid.

Conclusion

Bullous pemphigoid patients in this study had a younger age of onset and showed male preponderance. Comorbidities like type 2 diabetes, hypertension and neurological disorders were frequent. Cutaneous blisters were the most frequent clinical presentation. Systemic corticosteroids comprised the mainstay of therapy.
A case report of mesenteric involvement in neurofibromatosis type 1
Authors: Sang Nguyen Van , Ninh Tran Phan , Thanh Dang Trung , Thinh Nguyen Cuong
Published: July 2022

Mutations in the Neurofibromatosis Type 1 (NF-1) gene, which is located on chromosome 17q11.2, are the cause of NF-1, an autosomal dominant hereditary condition in which tumors of the nerve system develop. Neurological, skeletal, and cutaneous abnormalities are symptoms of the condition. Of all gastrointestinal tract lesions, mesentery lesions are the least common. There are many gastrointestinal problems that can accompany mesenteric neurofibromas, or they may not. We describe a case of a 5-year-old kid with mesenteric neurofibromatosis, which results in bowel obstruction and abdominal discomfort. On a CT scan, the mesenteric vasculature was completely encircled by homogenous soft tissue lesions without any vessel wall invasion. Diffuse mesentery lesions were discovered during surgery, although they could not be fully removed.
Impaired wound healing following cranial vault reconstruction in a patient with an atypical phenotype of Marfan syndrome: A case report
Authors: Recker Matthew J. , Kronenwetter Nathaniel , Reynolds Renée M. , Sadler Laurie S. , Markiewicz Michael R.
Published: July 2022

Background:

Marfan syndrome (MFS) is an autosomal dominant disorder of the connective tissues caused by mutations in the FBN1 gene which can result in widespread systemic involvement. Loeys-Dietz syndrome (LDS) is a related autosomal dominant disorder of connective tissue with widespread systemic involvement which has phenotypic overlap with MFS. LDS is caused by heterozygous pathogenic variants in six different genes, the most common of which involve transforming growth factor beta-receptor 1 or 2. While LDS is commonly associated with craniofacial manifestations, MFS is not typically characterized by craniosynostosis.

Case Description:

We present a 7-month-old female patient with MFS and metopic craniosynostosis with an unusual clinical presentation who underwent cranial vault reconstruction with fronto-orbital advancement and anterior cranial vault remodeling. Her course was complicated by impaired wound healing after surgery, requiring return to the operating room.

Conclusion:

Phenotypic overlap between genetic disorders can confound clinical diagnosis as illustrated in this case. Genetic testing can be highly valuable in the diagnosis of clinically variable disorders. Patients with MFS who undergo cranial surgery may be at increased risk for wound healing complications.
Calvarial angiomatous meningioma developed in the diploe
Authors: Sugiyama Hiroki , Tsutsumi Satoshi , Hashizume Akane , Kuroda Kiyotaka , Sugiyama Natsuki , Ueno Hideaki , Ishii Hisato
Published: July 2022

Background:

Angiomatous meningioma is a rare subtype of meningiomas. To the best of our knowledge, there have been no reports of intradiploic angiomatous meningioma.

Case Description:

A 53-year-old previously healthy woman was diagnosed with a calvarial lesion during a brain checkup. Cerebral magnetic resonance imaging showed an intradiploic tumor, 11 × 14 × 12 mm, in the right parietal bone. It was an enhancing, lobular tumor presenting as isointensity on T1- and hyperintensity on T2-weighted sequences, with an intense enhancement of the adjacent dura mater. Computed tomography revealed bone erosion at the tumor site, extending predominantly into the inner side, and sclerotic changes in the surrounding bone. Total resection was performed. Microscopically, the tumor tissue comprised cells with low-grade meningioma and intervening prominent vasculatures, consistent with angiomatous meningioma.

Conclusion:

Angiomatous meningioma should be considered as a differential diagnosis when an intradiploic tumor shows a lobular structure, intense enhancement of the adjacent dura mater, and sclerotic changes in the surrounding skull. These findings can support prompt tumor resection.
Spinal cord compression from cutaneous malignant peripheral nerve sheath tumor metastasis in a patient with neurofibromatosis Type 1
Authors: Calì Alessandro , Paolini Federica , Scalia Gianluca , Riolo Carmelo , Giuffrida Massimiliano , Iacopino Domenico Gerardo , Nicoletti Giovanni Federico
Published: July 2022

Background:

Neurofibromatosis Type 1 (NF-1) and previous irradiation are two common risk factors that can result in malignant peripheral nerve sheath tumors (MPNSTs), extremely rare soft-tissue sarcomas. Here, a 63-year-old male with NF-1 presented with diffuse spinal metastases from a subcutaneous MPNST.

Case Description:

A 63-year-old male with NF-1 presented acutely with paraplegia and urinary incontinence. Both CT and MR studies of the thoracic-lumbosacral spine showed multiple metastases from a subcutaneous MPNST. In addition, the patient had a T12 vertebral body pathological fracture.

Conclusion:

Despite its aggressive behavior, some cases of MPNST can be managed with gross total resection and adjuvant radiotherapy. In addition, in the presence of multiple metastases, chemotherapy may play an additional, although questionable role.
Why Ortho- and Para-Hydroxy Metabolites Can Scavenge Free Radicals That the Parent Atorvastatin Cannot? Important Pharmacologic Insight from Quantum Chemistry
Authors: Baldea Ioan
Published: July 2022

The pharmaceutical success of atorvastatin (ATV), a widely employed drug against the ``bad'' cholesterol (LDL) and cardiovascular diseases, traces back to its ability to scavenge free radicals. Unfortunately, information on its antioxidant properties is missing or unreliable. Here, we report detailed quantum chemical results for ATV and its ortho- and para-hydroxy metabolites (o-ATV, p-ATV) in methanolic phase. They comprise global reactivity indices, bond order indices and spin densities as well as all relevant enthalpies of reaction (bond dissociation BDE, ionization IP and electron attachment EA, proton detachment PDE and proton affinity PA, and electron transfer ETE). With these properties in hand, we can provide the first theoretical explanation of the experimental finding that, due to their free radical scavenging activity, ATV hydroxy metabolites rather than the parent ATV have substantial inhibitory effect on LDL and the like. Surprisingly (because it is contrary to the most cases currently known), we unambiguously found that HAT (direct hydrogen atom transfer) rather than SPLET (sequential proton loss electron transfer) or SET-PT (stepwise electron transfer proton transfer) is the thermodynamically preferred pathway by which o-ATV and p-ATV in methanolic phase can scavenge DPPH$^\bullet$ (1,1-diphenyl-2-picrylhydrazyl) radicals.
Ferrocene as an electrochemical reporting surrogate of abasic sites in DNA
Authors: Figazzolo Chiara , Ma Yifeng , Tucker James , Hollenstein Marcel
Published: July 2022

Methods for the real-time monitoring of the substrate acceptance of modified nucleotides by DNA polymerases are in high demand. In a step towards this aim, we have incorporated ferrocene-based abasic nucleotides into DNA templates and evaluated their compatibility with enzymatic synthesis of unmodified and modified DNA. All canonical nucleotides can be incorporated opposite ferrocene sites with a strong preference for purines. DNA polymerases with lesion-bypass capacity such as Dpo4 permit to resume DNA synthesis beyond the site of incorporation. Modified purine nucleotides can readily be incorporated opposite ferrocene basic site analogs, while pyrimidine nucleotides decorated with simple side-chains are also readily tolerated. These findings open up directions for the design of electrochemical sensing devices for the monitoring of enzymatic synthesis of modified DNA.
Ensemble Simulations of 2-Hydroxypropyl-β-cyclodextrin Complexes with All-Atom Molecular Dynamics Simulations
Authors: Munk Jeppe Tværmose , Nygaard-Thomsen Simon , Stokholm Thorleif Riis Bay , Langhorn Mads Rosander , Steinmann Casper
Published: July 2022

2-Hydroxypropyl-β-cyclodextrins (HP-β-CDs) ability to form inclusion complexes with lipophilic compounds is important both to treat Niemann Pick Type C disease and as part of a more general drug-formulation as a drug carrier. Theoretical studies of inclusion complexes with classical molecular dynamics simulations of HP-β-CDs are hampered by the fact that there are more than 2 million possible isomers to consider. We construct a general GLYCAM06 (Kirschner, K. N. et. al., J. Comput. Chem. 2007, 29, 622–655) compatible force field to treat all possible isomers of HP-β-CDs and investigate the effect on free energies of binding obtained from the MM/GBSA approach when increasing the degree of substitution. We find improved binding proportional to the added side chains. To show the applicability of the HP-β-CD force field, we generate an ensemble of simulations guided by experimentally determined distributions of isomers from mass spectrometry. Our results for ibuprofen and ketoprofen shows that acceptable accuracy in free energies of binding can be obtained with ensembles generated from around 40 isomers, but this is dependent on the guest molecule. We also investigate a simple linear relation between molecular log(P ) and free energy of binding for inclusion complexes of HP-β-CD. The linear model is promising but we find that the accuracy is too dependent on a single simulation. The presented force field and computational approach should provide for more realistic simulations.
Investigating diffusion pathways, mechanochemical milling and the electrochemical stability window for the Li5NCl2/Li9N2Cl3 solid electrolyte
Authors: Landgraf Victor , Famprikis Theodosios , Ganapathy Swapna , Bannenberg Lars , de Leeuw Joris , Wagemaker Marnix
Published: July 2022

Solid electrolytes which are thermodynamically stable against lithium metal may be key to stabilizing lithium metal/solid electrolyte interfaces which is crucial for realizing all solid state batteries that outperform conventional lithium ion batteries in terms of energy density. In this study we investigated LNCl (Li5NCl2 also often reported as Li9N2Cl3), a solid electrolyte that is thermodynamically stable against lithium metal and which features a partially occupied lithium sub-lattice. Combining experiments and simulations we investigated the lithium diffusion mechanism, the effects of mechanochemical treatment and the electrochemical stability window of LNCl. We found that a wide spread of different lithium jumps can occur in LNCl with certain jumps being much more diffusion limiting than others. Additionally, Li nuclear magnetic resonance (NMR) experiments show that fast Li motion (σRT > 0.1 mS cm-1) is present in LNCl which is however not accessible in macroscopic LNCl pellets (σRT~1·10-3 mS cm-1). Ball milling LNCl improves the macroscopic conductivity by one order of magnitude (σRT = 0.015 mS cm-1) and we show for the first time that LNCl can be synthesized mechanochemically without any heat treatment step. Previously, the anodic limit of LNCl was reported to be >2V vs Li+/Li but this study shows that the true anodic limit of LNCl is ~0.6 V (vs Li+/Li) which is in close agreement with our first-principles calculations. Based on our results we conclude that the anodic limit of LNCl confines its applicability to an artificial buffer layer between the lithium metal anode and other highly-conducting solid electrolytes and we computationally investigate the chemical compatibility of LNCl with common highly-conducting solid electrolytes.
Preschool Children Without 7-repeat DRD4 Gene More Likely to Develop Disorganized Attachment Style
Authors: Graffi Justin , Moss Ellen , Jolicoeur-Martineau Alexis , Moss Gal , Lecompte Vanessa , Pascuzzo Katherine , Babineau Vanessa , Gordon-Green Cathryn , Mileva-Seitz Viara , Minde Klaus , Sassi Roberto , Carrey Normand , Kennedy James , Gaudreau Helene , Levitan Robert , Meaney Michael , Wazana Ashley
Published: July 2022

Background: A disorganized attachment style is characterized by fearful and disoriented behaviours when a child is separated from their caregiver. Its presence is an early predictor of the later development of psychopathology, including depression. This study seeks to determine the effects of one environmental factor - the incidence of low birth weight - and one genetic factor - the presence of the long (7-repeat) polymorphism of the dopamine D4 receptor (DRD4) gene - on the development of disorganized attachment between the child and the mother.

Methods: We sampled 251 mother-child dyads from the Maternal Adversity, Vulnerability and Neurodevelopment (MAVAN) project. We measured birth weight and DRD4 genotype, and assessed attachment style using modified separation-reunion procedure.

Results: Birth weight did not have a significant effect on disorganized attachment (b=-0.001, t(230)=0.006, p=0.910). Presence of DRD4 7-repeat polymorphism had a significant negative effect on presence of disorganized attachment style (b=-1.196, t(230)=0.411, p=0.004).

Conclusion: Children without the DRD4 7-repeat allele were more likely to display a disorganized attachment style compared to children with the DRD4 7-repeat allele. This indicates that the 7-repeat allele of the DRD4 gene may serve as a protective factor against disorganized attachment.
Fluorescence Imaging of Receptor Activator of Nuclear Factor Kappa-B Ligand-Mediated Calcium Oscillations in Osteoclasts
Authors: Stavnichuk Mariya , Sadvakassova Gulzhakhan , Komarova Svetlana
Published: July 2022

Background: Numerous bone diseases are caused by abnormal activity of osteoclasts, cells responsible for physiological bone degradation. Understanding the mechanisms of osteoclast formation and activation is important for developing diagnostic tools and treatments for various bone diseases. Receptor activator of nuclear factor κB ligand (RANKL), a key osteoclastogenic cytokine, induces changes in intracellular Ca2+ con- centration ([Ca2+]i) that can be visualized and measured with a fluorescent Ca2+ binding dye. The objective of the study was to characterize the changes in [Ca2+]i induced by acute application of RANKL in osteoclast precursors.

Methods: We performed calcium imaging in osteoclast precursors generated from RAW 264.7 cells loaded with Fura-2 fluorescent dye using an inverted microscope, Nikon TE2000-U. Data was collected with Volocity software and analysed in Excel and MATLAB.

Results: In osteoclast precursors, RANKL induced oscillations in [Ca2+]i within 2 minutes of exposure. The main frequency of oscillations was approximately 37.7 mHz. However, no significant change in the mean level of intracellular Ca2+ was observed. Interestingly, when ATP was applied to RANKL-treated osteoclast precursors, it induced a long-lasting increase in [Ca2+]i compared to control cells.

Limitations: The limitations of our study included the small number of replicates and the short duration of fluorescence recording under each condition.

Conclusions: Short exposure of osteoclast precursors to RANKL not only induced oscillations in calcium con- centration, but also modulated cellular response to the subsequent application of ATP.
Loss-of-Function Analysis Elucidates Essential Roles of eIF4E Isoforms in Drosophila Spermatogenesis
Authors: Chen Liang
Published: July 2022

Background: Through transcriptional and post-transcriptional regulation, eukaryotic cells can control gene expression to moderate vital cell processes and induce morphological changes. In developmental biology, translation initiation is emerging as a key player in gene expression regulation. Translation initiation begins when eukaryotic initiation factor 4E (eIF4E) binds the 5’ mRNA cap to recruit other initiation factors. Eight eIF4E isoforms are present in Drosophila melanogaster. The canonical eIF4E-1 is involved in the translation of all genes and is a common target for translational regulation mechanisms. The activity of testis-specific eIF4Es in Drosophila are largely unclear, but recent evidence on eIF4E-3 suggests that the other isoforms may also possess distinct, essential functions in spermatogenesis.

Methods: Here we provide protein localization data and loss-of-function analysis to characterize eIF4E-4, eIF4E-5, and eIF4E-7.

Results: Single KD showed few phenotypes, while eIF4E-4/eIF4E-5 double knockdown males had severe de- fects in spermatogenesis. In eIF4E-5/eIF4E-7 double knockdowns, mutations manifested in multiple stages of severity.

Conclusions: The unique expression patterns and differential mutant phenotypes observed suggest that the testis-specific isoforms contain varying levels of functional redundancy. eIF4E-4 and eIF4E-5, which share close homology, appear to have overlapping roles in regulating germ cell division during early spermato- genesis. However, during spermatid individualization they seem to assume different functions. eIF4E-7 also appears to be involved in germ cell differentiation, but most likely in a separate mechanism due to the inability of other isoforms to compensate for its knockdown.
Role of Ubiquitin in the Survival of Legionella pneumophila in Eukaryotic Host Cells
Authors: Wang Si Jia
Published: July 2022

Background: Eukaryotic cells use essential ubiquitin-mediated pathways in their defense against pathogenic bacteria, such as Legionella pneumophila, the intracellular pathogen of Legionnaire’s disease. Despite the protective role of these pathways, L. pneumophila virulence has evolved to secrete numerous effector proteins involved in co-opting host ubiquitin-mediated processes to facilitate their survival. Many of these effector proteins are of great research interest in the quest to demystify the molecular mechanisms underlying L. pneumophila pathogenesis as the bacterium has a vast repertoire of effector proteins.
Methods: Articles were obtained from scientific literature databases such as PubMed and the McGill library. Selected articles provided an overview of the ubiquitination pathway, eukaryotic autophagy, L. pneumophila pathogenesis, and structural and functional analysis of L. pneumophila and other bacterial effectors involved in subverting host ubiquitin systems.
Summary: This review discusses the current structural and functional characterization of L. pneumophila protein effectors involved in exploiting host ubiquitin machinery to facilitate intracellular bacterial survival. These protein effectors include those with E3 ubiquitin ligase activity, LubX, AnkB, and SidC, which respectively mediate bacterial nutrient acquisition, temporal regulation of other effectors, and remodelling of the L. pneumophila replicative niche; the SidE family of effectors, which mediates the first novel, single-enzyme ubiquitination pathway and deubiquitination; and ravZ, a protease promoting evasion of host autophagy. However, the exact molecular functions and biological consequences of these effectors as well as the full repertoire of L. pneumophila effectors facilitating ubiquitin-mediated survival still require further investigation.
Antarctic Sea Ice Trends: Insights from a Suite of Climate Models
Authors: Sauvé Jade , Dufour Carolina , Griffes Stephen M. , Winton Michael
Published: July 2022

Background: Antarctic sea ice concentration has been observed to increase from 1978 to 2015, in contrast with the decrease that most climate models show. Here, we aim to examine the respective roles of natural variability and anthropogenic forcing in shaping Antarctic sea ice trend.
Method: To do so, we use the GFDL-CM2 coupled climate model with varying horizontal resolutions in the ocean (1°, 0.25° and 0.10°) that displays a range of behaviours in natural variability with the representation of Weddell Sea polynyas, and different intensities in the decrease of sea ice under climate change.
Results: In the 0.10° model, a sea ice trend of similar sign and magnitude to that observed over the satellite record is found between two occurrences of the Weddell Sea polynya. In the 1° and 0.25° models, which do not simulate any polynya, no equivalent trend of what the satellite record shows is found. Under increasing CO2 forcing, all models show a surface cooling on a short time scale (years) south of 50°S, followed by a warming on a longer time scale (decades), consistent with the delayed warming mechanism of Ferreira et al. (2015). Of all models, the higher resolution model shows the strongest surface warming and decrease in sea ice, suggesting an important role for mesoscale eddies in the response of Antarctic sea ice to climate change.
Conclusion: We conclude that the Weddell Sea polynya is key to the representation of the sea ice trend and that the disagreement between models and observations might partly arise from a desynchronization of the polynya cycles or a too weak natural variability of sea ice in models compared to observations.
Bionic Human: A Review of Interface Modalities for Externally Powered Prosthetic Limbs
Authors: Mundkur Nipun
Published: July 2022

Background: The loss of a limb is a debilitating incident and can leave patients significantly disabled and often unable to perform activities of daily living. Prosthetic limbs can provide some modicum of normalcy back to their lives, and there has been much research over the past few decades into restoration of biomedical and physiological function with the use of externally powered and robotic prostheses. This review aims to explore the various approaches to machine-body interfacing that can be employed to achieve intuitive and meaningful control of these complex devices, and to discuss the individual benefits and drawbacks of each method.
Methods: Studies looked at include both primary and secondary sources of research. Identification was via a PubMed search for the terms “prosthetic limb”, “powered prostheses”, “myoelectric prostheses”, “neural interface”, “prosthetic somatosensory feedback”, and “brain-machine interface”, which resulted in a total of 3892 papers retrieved. Of these, 28 were retained as sources for this review. Selection was based on relevance to control of powered prostheses.
Summary: Significant strides have been made in expanding the choice of interface sites for bionic prosthesis control. Muscles, nerves, and the brain are all options, each with varying degrees of invasiveness and corresponding resolution of information obtained, and non-muscle interfacing prostheses may soon be commercially available. These advances have allowed for increasingly precise control of prosthetic limbs. However, this is limited by the challenge of returning sensory information from the prosthesis back to the user.
Coastal Sea-Ice Break-Up Events in Beringia
Authors: Aucoin Samuel , Tremblay Bruno , Newton Robert
Published: July 2022

We quantify changes in break‐up events of landfast ice in the transition from a perennial to a seasonal sea ice cover in the Arctic. A break‐up event is defined as a time when coastal sea ice concentration drops below 95% after a minimum period of 10 days of stable ice conditions. To this end we analyze output diagnostics from the Community Earth System Model (Version 1) – Large Ensemble from 1920 to 2080, focusing on six coastal communities of Alaska, Chukotka, and the Kamtchatka Peninsula: Utqiaġvik, Point Hope, Gambell, Novoye Chaplino, Sireniki, and Pakhachi. Model results generally agree with the satellite record with open water formation along the coastline associated with sustained offshore winds, although the sensitivity of CESM1‐LE is higher than that of observations due to the absence of a landfast ice parameterization in CESM1‐ LE. Specifically, we see a linear relationship between the magnitude of the opening and offshore surface wind stresses integrated over the 10 days prior to the opening event, (p‐value < 0.01). While the break‐up event frequency increases (5.53 × 10−5 events/day/year for Utqiagvik) in the 21st century due to the thin- ning, or weakening, of the landfast ice cover, the total number of winter break‐up events decreases due to a shortening of the winter season (mean of ‐5.3 days/decade).
Quantifying the Albedo of the Montreal Island and its Potential for Increase
Authors: Frie Elena , Gilmer Saskia , Buraga Bryan , Franceschini Kevin
Published: July 2022

Urbanization has changed the Earth’s surface, resulting in the urban heat island effect. There has been a recent focus on increasing urban albedo as a strategy to mitigate this phenomenon. Studies on Montreal’s albedo have primarily looked at the impact of albedo manipulations upon the urban heat island effect. However, the current albedo of the island, broken down by land use type, has yet to be quantified. Therefore, previous studies often rely on generalized urban albedo and land use estimates that have not been proven to be generalizable to Montreal. This study attempted to quantify the current albedo of the Island of Montreal through urban land use categorization. The findings were then used to estimate albedo increase under different roof replacement scenarios. Data sets for building footprints, vegetation, and roadways were incomplete in Montreal, requiring the combination of several sources to obtain representative data for analysis. This study found the albedo of Montreal island to be 0.19 ± 0.057. Further, the hypothetical roof change scenarios then aligned with a 0.1 albedo increase, which is the albedo change used in current urban heat island effect mitigation literature. Using the albedo increase potential that resulted from the three scenarios tested here, future research should explore further estimation of the associated surface and air temperature decrease.
Potential for use of Spent Substrate of Pleurotus Mushrooms Grown on Urban Waste as Feed for Dairy Cattle
Authors: Van Wyk Liesl
Published: July 2022

Mushroom wastes are available in high volumes, with 5 million tons of spent mushroom substrate (SMS) being disposed of globally every year. Due to this high availability, various forms of SMS have been researched for their use as alternative animal feeds. Additionally, experimental techniques can be used to grow certain mushroom species, such as oyster mushrooms (Pleurotus sp.) on various lignocellulosic waste materials. Therefore, the SMS from Pleurotus sp. grown on these waste materials may offer a promising conversion from a waste material to a low-cost, nutritionally sufficient feed. However, little research has been done to determine if feeds from Pleurotus SMS specifically grown on urban waste substrates offer the same benefits. Given rising awareness on circularity and urban self-sufficiency, growing mushrooms on urban waste is a promising solution which should be investigated. This paper assesses the feasibility of using SMS from golden oyster mushrooms (Pleurotus citrinopileatus) grown on urban waste as dairy cattle feed, comparing substrate ratios to determine which would result in the most desirable protein and fiber contents. SMS from three experimental substrates of cardboard and spent coffee grounds (SCG) were compared to traditional dairy cattle feeds. Treatments 2 and 3 were found to be suitable for use as additives to traditional feeds in small replacement amounts. However, both treatments also had high fiber content, which may affect practicality of use as feeds.
The Role of Compensatory Beliefs and Self-efficacy on Treatment Adherence in Adolescents with Type 1 Diabetes
Authors: Nguyen Thien-Kim , Knäuper Bärbel , Rabiau Marjorie
Published: July 2022

Many adolescents suffering from type 1 diabetes have difficulty following the strict demands of their treatment, which can lead to serious health complications. Previous research has shown that self-efficacy, or the conviction that one can achieve a certain goal, has a positive effect on adherence to treatment. We propose that compensatory beliefs (CBs) also have a significant impact on the adherence to treatment which explains why diabetic teenagers fail to fully adhere to their proposed treatment. In a sample of 115 diabetic adolescents, inaccurate compensatory beliefs significantly correlated with poor glycemic control, self-reported blood-sugar monitoring and diet. However, self-efficacy did not significantly correlate with CB levels and accurate compensatory beliefs were not significantly linked of many of the measures of treatment adherence.
Investigation on stereoconfiguration of azoxybenzene formed via Grignard reaction and further Consequences on Z & E isomerism of diazeniumdiolates
Authors: Rivalti Daniel , Bohle D. Scott , Moore Raecca , Dodd Erin
Published: July 2022

Nitric oxide’s importance in biochemistry was recognized in the mid 1980’s. Nitric oxide (NO) is critical for the function of neuronal cells, for blood flow and to defend against tumour cells and microorganisms. Diazeniumdiolates, ions of structure [RN(O)NO]-, are being used as probes to study the biological and pharmacological implications of NO because compounds bearing this functional group have been found to release NO. The conformation about the N=N double bond of diazeniumdiolates has been shown through crystallographic studies to be predominantly Z. To study the stereospecificity of diazeniumdiolates, azoxybenzene was synthesized via a “forgotten” synthetic pathway pioneered by Stevens in 1963 which involved a reaction between an organonitrosohydroxylamine tosylate, RN(O)NOTs, and a Grignard reagent. The product from this preparation was directly compared to azoxybenzene made from a coupling reaction.
Shifts in species traits among North American freshwater fish assemblages: ecological homogenization?
Authors: Elvidge Chris , Ricciardi Anthony
Published: July 2022

This study examines whether the processes of species invasion and extirpation have produced distinct shifts in mean species traits of North American freshwater fish assemblages. An analysis of 54 species (29 invaders, 25 extirpated taxa) in 7 drainages revealed significant differences in maximum length, native latitudinal range size, habitat specificity, and migratory behaviour. Results suggest a pattern in which extirpated species are being replaced by larger, more environmentally tolerant species capable of occupying a broader range of habitats. Freshwater fish assemblages containing introduced generalist species may have a selective advantage over pristine communities as human-dominated landscapes continue to replace natural systems.
effect of density stratification and a cape in a baroclinic western boundary current separation experiment
Authors: Fan Xue , Cornillon Peter , Eichmann Andrew , Sheremet Vitalii
Published: July 2022

Western boundary current separation has long been a mystery. For the Gulf Stream, different factors such as the coastal shape, inflow and outflow location, wind stresses, continental shelf slope, shallow underwater plateaus, and interaction with the deep circulation potentially play unique and important roles in separating the Gulf Stream from the coast. To study these effects, a model consisting of a circular tank of water rotating on a spinning table was set up. Sloping planes form the upper and lower boundaries of the enclosed tank, approximating the Coriolis force. Then, water was pumped through gaps in the tank, producing a western boundary current and an artificial cape having the geometry of Cape Hatteras at the Gulf Stream’s point of separation was introduced into the system. Finally, to study the effects of stratification on the point of separation, a 2-layer system was used. The results of varying different parameters, such as flow rate or density difference between layers, were compared with observations of the Gulf Stream and output from a numerical model. Ultimately, the experimental results showed that density differences alone do not affect the separation point to a meaningful degree, but rather that it is the position of inflow and outflow gaps that are much more significant. Density differences alone do not significantly affect the separation point. The relationship between high flow rates tending to create more modes of oscillation and a moving separation point was also observed. More so than any other setup, a cape at high density difference and low flow rate deflects the western boundary current flow. The results suggest that the interplay between the 1-layer and 2-layer modes is relevant to the oceanic case.
Roles of Dopamine D1 and D2 Receptors in Working Memory Function
Authors: Liggins John
Published: July 2022

Dopamine has been implicated in the modulation of working memory via its interactions with circuits located in the prefrontal cortex of rodents and non-human primates. However, the role that pathways triggered by dopamine receptor subtypes play in affecting processes of working memory remains unclear. In humans, the evidence for dopaminergic modulation of working memory is controversial and the neurological substrates for dopamine’s modulatory effects are not fully understood. This paper will review the major animal and human studies that implicate synaptic dopaminergic transmission in working memory function and will outline a new framework to clarify the specific contribution of dopamine D2 receptors to the performance of this cognitive function. Specifically, it is proposed that activation of hippocampal dopamine D2 receptors by chemical agonists could result in the enhancement of spatial working memory.
Genomic and Phenotypic Variability of Mycobaterium avium Subspecies
Authors: Dadvar Ehsan
Published: July 2022

Introduction: Mycobacterium avium complex consists of M. intracellulare and the subspecies of M. avium subsp. avium, M. avium subsp. paratuberculosis and M. avium subsp. hominissuis. Despite their taxonomic relationship, these subspecies are organisms with distinct phenotypes, ranging from environmental bacteria that cause infections in immunocompromised hosts to pathogens targeting birds and ruminants. The reasons for the variable pathogenicity and host range of M. avium subspecies are not known. We hypothesize that genotypic differences between M. avium subsp. avium and M. avium subsp. paraturberculosis can explain different pathogenic outcomes. Methods: We used tri-genomic comparisons to look for DNA fragments unique to each subspecies. We also used an acute model of mouse infection to determine different phenotypic outcomes in response to infection with different Mycobacterium subspecies. results: Through tri-genomic comparisons we identified genetic regions of interest that may contain genes to explain phenotypic or pathogenic differences among subspecies. In an 8 week course infection, mice infected with M. avium subspecies avium had the highest bacterial burden in their spleens and livers. at the same time, mice infected with M. avium subspecies paraturberculosis had the lowest bacterial burden. discussion: Differences in the genomic sequences of the M. avium subspecies suggests that these sequences encode pathogenic factors. Consequently, this study shows that the sequencing of M. avium subspecies genomes can be useful for predicting and explaining variation in pathogenesis.
Role of Dscam mediated self-avoidance and tiling in neural branching
Authors: Ghiasi Marzieh
Published: July 2022

Dscams (down syndrome cell adhesion molecules) play an important role in the formation of neural circuits. Various studies have highlighted the role of dscams in two major wiring strate- gies, self-avoidance and tiling, leading to broad and uniform branching. The Drosophila dscam1 protein, which has thousands of isoforms formed by alternative splicing, has been shown to confer unique identities to cells and mediate homotypic recognition, homophilic repulsion and consequently self-avoidance behavior between neurites of a single neuron. The Drosophila dscam2 protein mediates homophilic repulsion between projections from the same class of cells, in a process called tiling. The vertebrate dscam has been shown to mediate both tilingand self-avoidance. however, the mechanisms by which this is accomplished in the absence of homotypic recognition are unclear. This review provides an overview of functional similarities and differences between dscam homologues in invertebrate and vertebrate species, and describes some mechanisms proposed to account for these differences.
Protection of the differentiated Chondrocyte Phenotype during Monolayer expansion Cultures Using heat inactivated Fetal Calf Serum
Authors: Ng Tat Fong , Matmati Mourad , Quinn Thomas M.
Published: July 2022

Introduction: autologous chondrocyte implantation (aci) is one successful treatment for osteoarthritic defects (1-4). However, chondrocytes undergo a conversion to a fibroblastic phenotype during their expansion in vitro. This process can lead to degradation and failure of the repaired tissue, and is termed “dedifferentiation” (5-9). we hypothesized that culturing chondrocytes in Heat inactivated Fetal calf serum (HiFcs) would lead to a slowing of the process of dedifferentiation. This study specifically examines how HiFcs affects gene expression and proliferation of bovine chondrocytes in short-term monolayer culture. Methods: we cultured primary chondrocytes extracted from bovine joints in Fcs or HiFcs for four passages (p0-p4). we then analysed the relative gene expression of aggrecan (agg), type ii-alpha1 collagen (col2a1), cartilage oligomeric matrix protein (comp), sry (sex determining region y)-box 9 (sox9), type i-alpha2 collagen (col1a2) and bcl-2-associated X protein (bax) using quantitative real-time polymerase chain reaction (qpcr). results: our results show significant down-regulation of col1a2 and up-regulations of agg, col2a1, comp and sox9 in HiFcs cultures when compared to those in Fcs cultures. discussion: Agg, col2a1 and comp are associated with the synthesis of cartilage matrix molecules while sox9 is associated with chondrogenesis (5-11). Col1a2 is associated with the presence of fibrous tissue which lacks the desired mechanical properties (5-9). Therefore, our results suggest that HiFcs can partially protect the chondrocytic phenotype from dedifferentiating to fibroblastic after one passage. To improve upon our results, more experiments are required to reveal the mechanism underlying the protection of chondrocytes offered by the heat inactivation of Fcs.
Rattling the core of a well-established paradigm: is retinoic acid really necessary for meiosis entry?
Authors: Chang Brian (Po-yen)
Published: July 2022

Independent studies from recent years have yielded a wealth of evidence supporting the model that retinoic acid (RA) triggers the expression of stimulated by retinoic acid 8 (Stra8) gene in germ cells thereby inducing their entry into meiosis (1, 2). Kumar et al.’s recent work published in 2011, however, boldly challenges this model, proposing that entry into meiosis, in fact, takes place independently of endogenous RA (3). This controversial claim has attracted intense interest in the field of developmental biology and has prompted several follow-up studies. one of these studies has proposed two homeobox genes, Msx1 and Msx2, to also be necessary for female meiosis initiation, and that their actions are likely mediated by the expression of Stra8 (4).