Homotopy Structure of 5d Vacua

It is shown that flat zero-energy solutions (vacua) of the 5d Kaluza-Klein theory admit a non-trivial homotopy structure generated by certain Kaluza-Klein excitations. These vacua consist of an infinite set of homotopically different spacetimes denoted by $\mathcal{M}^{(n)}_5$, among which $\mathcal{M}^{(0)}_5$ and $\mathcal{M}^{(1)}_5$ are especially identified as $M_{4} \times S^{1}$ and $M_5$, the ground states of the 5d Kaluza-Klein theory and the 5d general relativity, respectively (where $M_k$ represents the $k$-dimensional Minkowski space).Comment: 8 page

On integer partitions corresponding to numerical semigroups

Numerical semigroups are cofinite additive submonoids of the natural numbers. In 2011, Keith and Nath illustrated an injection from numerical semigroups to integer partitions. We explore this connection between partitions and numerical semigroups with a focus on classifying the partitions that appear in the image of the injection from numerical semigroups. In particular, we count the number of partitions that correspond to numerical semigroups in terms of genus, Frobenius number, and multiplicity, with some restrictions

Optimization of Long-Term Human iPSC-Derived Spinal Motor Neuron Culture Using a Dendritic Polyglycerol Amine-Based Substrate

Human induced pluripotent stem cells (hiPSCs) derived from healthy and diseased individuals can give rise to many cell types, facilitating the study of mechanisms of development, human disease modeling, and early drug target validation. In this context, experimental model systems based on hiPSC-derived motor neurons (MNs) have been used to study MN diseases such as spinal muscular atrophy and amyotrophic lateral sclerosis. Modeling MN disease using hiPSC-based approaches requires culture conditions that can recapitulate in a dish the events underlying differentiation, maturation, aging, and death of MNs. Current hiPSC-derived MN-based applications are often hampered by limitations in our ability to monitor MN morphology, survival, and other functional properties over a prolonged timeframe, underscoring the need for improved long-term culture conditions. Here we describe a cytocompatible dendritic polyglycerol amine (dPGA) substrate-based method for prolonged culture of hiPSC-derived MNs. We provide evidence that MNs cultured on dPGA-coated dishes are more amenable to long-term study of cell viability, molecular identity, and spontaneous network electrophysiological activity. The present study has the potential to improve hiPSC-based studies of human MN biology and disease. We describe the use of a new coating substrate providing improved conditions for long-term cultures of human iPSC-derived motor neurons, thus allowing evaluation of cell viability, molecular identity, spontaneous network electrophysiological activity, and single-cell RNA sequencing of mature motor neurons

Eye enucleation and exenteration in -cattle: a retrospective study of 38 cases (2013-2020).

INTRODUCTION The study aimed to describe clinical indications for eye enucleation and exenteration, the occurrence of complications and long-term outcome in cattle, and examine owners' attitude towards enucleation and exenteration and their satisfaction with the surgical outcome. Medical records from the two veterinary teaching hospitals in Switzerland were reviewed to identify cattle that underwent unilateral enucleation or exenteration between January 2013 and December 2020. Data extracted included medical history, ocular examination, clinical diagnosis, surgical procedure including anesthesia, suture material and pattern used, complications, and treatment thereof. Long-term follow-up was evaluated via national animal database inquiries to determine survival time and via owners' interviews with the use of a standardized questionnaire that included questions regarding the occurrence of complications and reason for culling, production performances and perceived quality of life after surgery, concerns, factors affecting the decision to proceed with surgery, and general satisfaction with the outcome. Descriptive statistics, Fisher's exact tests and unpaired t-test were used to summarize the data and assess association between variables. Association was considered significant if p < 0,05. Thirty-eight cases were identified, with a median age of 5 years. More than half of the cases (55,3 %) were diagnosed with non-neoplastic ocular lesions represented by severe trauma with loss of globe content, globe rupture with history of infectious keratoconjunctivitis or hypopyon, or congenital malformations. The remaining cases were diagnosed with neoplastic lesions, including ocular squamous cell carcinoma (OSCC), melanoma, or sarcoma. Complications following surgery were reported in 29 % of cases and included postoperative infection and recurrence of OSCC. There was no significant association between ocular diagnosis and the occurrence of postoperative complications or survival time. Surgery did not seem to influence the animals' postoperative production performance or the perceived quality of life. Most owners (92 %) were satisfied with the surgical outcome. The occurrence of postoperative complications leading to increased overall costs and culling was the main reason for lower owner satisfaction

Expression of a rice chitinase gene in transgenic banana (''Gros Michel'', AAA genome group) confers resistance to black leaf streak disease

Transgenic banana (Musa acuminata 'Gros Michel') integrating either of two rice chitinase genes was generated and its resistance to Black Leaf Streak disease caused by the fungus Mycosphaerella fijiensis was tested using a leaf disk bioassay. PCR screening indicated the presence of the hpt selectable marker gene in more than 90 % of the lines tested, whereas more than three quarters of the lines contained the linked rice chitinase gene resulting in a co-transformation frequency of at least 71.4 %. Further, a unique stable integration of the transgenes in each line revealed some false negative PCR results and the expected co-transformation frequency of 100 %

Aetiology of canine infectious respiratory disease complex and prevalence of its pathogens in Europe

The canine infectious respiratory disease complex (CIRDC) is an endemic worldwide syndrome involving multiple viral and bacterial pathogens. Traditionally, Bordetella bronchiseptica (Bb), canine adenovirus type 2 (CAV-2), canine distemper virus (CDV), canine herpesvirus (CHV) and canine parainfluenza virus (CPiV) were considered the major causative agents. Lately, new pathogens have been implicated in the development of CIRDC, namely canine influenza virus (CIV), canine respiratory coronavirus (CRCoV), canine pneumovirus (CnPnV), Mycoplasma cynos and Streptococcus equi subspecies zooepidemicus. To better understand the role of the different pathogens in the development of CIRDC and their epidemiological relevance in Europe, prevalence data were collected from peer-reviewed publications and summarized. Evidence of exposure to Bb is frequently found in healthy and diseased dogs and client-owned dogs are as likely to be infected as kennelled dogs. Co-infections with viral pathogens are common. The findings confirm that Bb is an important cause of CIRDC in Europe. CAV-2 and CDV recovery rates from healthy and diseased dogs are low and the most likely explanation for this is control through vaccination. Seroconversion to CHV can be demonstrated following CIRDC outbreaks and CHV has been detected in the lower respiratory tract of diseased dogs. There is some evidence that CHV is not a primary cause of CIRDC, but opportunistically re-activates at the time of infection and exacerbates the disease. The currently available data suggest that CIV is, at present, neither a prevalent nor a significant pathogen in Europe. CPiV remains an important pathogen in CIRDC and facilitates co-infection with other viral and bacterial pathogens. CnPnV and CRCoV are important new elements in the aetiology of CIRDC and spread particularly well in multi-dog establishments. M. cynos is common in Europe and is more likely to occur in younger and kennelled dogs. This organism is frequently found together with other CIRDC pathogens and is significantly associated with more severe respiratory signs. S. zooepidemicus infection is not common and appears to be a particular problem in kennels. Protective immunity against respiratory diseases is rarely complete, and generally only a reduction in clinical signs and excretion of pathogen can be achieved through vaccination. However, even vaccines that only reduce and do not prevent infection carry epidemiological advantages. They reduce spread, increase herd immunity and decrease usage of antimicrobials. Recommending vaccination of dogs against pathogens of CIRDC will directly provide epidemiological advantages to the population and the individual dog

O adsorption and incipient oxidation of the Mg(0001) surface

First principles density functional calculations are used to study the early oxidation stages of the Mg(0001) surface for oxygen coverages 1/16 <= Theta <= 3 monolayers. It is found that at very low coverages O is incorporated below the topmost Mg layer in tetrahedral sites. At higher oxygen-load the binding in on-surface sites is increased but at one monolayer coverage the on-surface binding is still about 60 meV weaker than for subsurface sites. The subsurface octahedral sites are found to be unfavorable compared to subsurface tetrahedral sites and to on-surface sites. At higher coverages oxygen adsorbs both under the surface and up. Our calculations predict island formation and clustering of incorporated and adsorbed oxygen in agreement with previous calculations. The calculated configurations are compared with the angle-scanned x-ray photoelectron diffraction experiment to determine the geometrical structure of the oxidized Mg(0001) surface.Comment: 10 pages, 5 figure