Restoration of Fertility after Removal of Extrauterine Mirena Coil: A Case Report and Review of the Literature

We present the case of a 27-year-old lady who was seen in the infertility clinic with a history of secondary infertility of a one-year duration. She had a hysteroscopy and Mirena insertion for heavy periods. Coil strings were not found by the GP during first coil check six weeks after insertion. A pelvic ultrasound scan did not show any coil, and it was not investigated further with a possible diagnosis of coil expulsion made. One year following that, she was seen in the infertility clinic. Initial investigations revealed anovulation, and HSG located the coil to be extrauterine. Mirena was removed laparoscopically, and a month following the removal she conceived. She is currently pregnant. This case highlights the effect of extrauterine mirena coils on fertility by possibly causing higher plasma levels of levonorgesterol and resulting suppression of ovulation. Laparoscopic removal of mirena coil can help in restoration of fertility

Trade-offs between precision and fluctuations in charging finite-dimensional quantum systems

Within quantum thermodynamics, many tasks are modelled by processes that require work sources represented by out-of-equilibrium quantum systems, often dubbed quantum batteries, in which work can be deposited or from which work can be extracted. Here we consider quantum batteries modelled as finite-dimensional quantum systems initially in thermal equilibrium that are charged via cyclic Hamiltonian processes. We present optimal or near-optimal protocols for $N$ identical two-level systems and individual $d$-level systems with equally spaced energy gaps in terms of the charging precision and work fluctuations during the charging process. We analyze the trade-off between these figures of merit as well as the performance of local and global operations.Comment: 14+2 pages, 7 figure

L’efficience économique de la flat-tax

Historiquement, l'instauration d'impôt unique a été considérée comme une amélioration fiscale, par rapport à une situation où bien souvent clergé et noblesse étaient exemptés d'impôts. Sébastien Le Prestre de Vauban fut le premier à proposer un système d'impôt unique proportionnel et la suppression des privilèges fiscaux (il publie anonymement en 1707 l'ouvrage La Dîme royale qui expose ses idées). Ces privilèges furent l'une des causes de la Révolution française. Durant le XIXe siècle, des impôts à taux unique ont ainsi été finalement mis en place dans la plupart des pays européens.Après la Première Guerre mondiale, de nombreux pays la remplacèrent par un impôt progressif afin de financer les "avancées sociales" de l'époque. Depuis, certains économistes sont parvenus à la conclusion que des taux très élevés pour les plus hautes tranches d'imposition sont inutiles à cause de l'évasion fiscale.Ainsi, l'impôt à taux unique a fait un retour sur scène ces dernières années du fait de son instauration dans plusieurs pays anciennement communistes de l'Europe de l'Est, instauration qui s'est globalement révélée réussie. Les taux moyens sont autour de 12 % (par exemple 10 % en Bulgarie, 13 % en Russie).Analyser les principes de fonctionnement de la flat tax (chapitre 1) et connaître la pratique des pays ayant déjà franchi le pas (chapitre 2 ) est nécessaire pour savoir où se situent les  freins  à  la  généralisation  de  la  flat  tax  dans  l’ensemble  des  pays  de  l’Union européenne.La flat tax présente aux yeux de ses deux initiateurs, Robert Hall et Alvin Rabushka, les trois  qualités  essentielles  à  un  mode  d’imposition :  la  simplicité  ,  l’équité, l’efficience économique. Ces trois qualités combinées feraient de la  flat  tax  un  mode  d’imposition  idéal.  Ces  trois  qualités  revendiquées  feront  l’objet d’analyses successives

The crystal structure of Pneumolysin at 2.0 Å resolution reveals the molecular packing of the pre-pore complex

Pneumolysin is a cholesterol-dependent cytolysin (CDC) and virulence factor of Streptococcus pneumoniae. It kills cells by forming pores assembled from oligomeric rings in cholesterol-containing membranes. Cryo-EM has revealed the structures of the membrane-surface bound pre-pore and inserted-pore oligomers, however the molecular contacts that mediate these oligomers are unknown because high-resolution information is not available. Here we have determined the crystal structure of full-length pneumolysin at 1.98 Å resolution. In the structure, crystal contacts demonstrate the likely interactions that enable polymerisation on the cell membrane and the molecular packing of the pre-pore complex. The hemolytic activity is abrogated in mutants that disrupt these intermolecular contacts, highlighting their importance during pore formation. An additional crystal structure of the membrane-binding domain alone suggests that changes in the conformation of a tryptophan rich-loop at the base of the toxin promote monomer-monomer interactions upon membrane binding by creating new contacts. Notably, residues at the interface are conserved in other members of the CDC family, suggesting a common mechanism for pore and pre-pore assembly

Triple domestic heat recovery system: thermal modeling and parametric study

International audienc

Domestic thermoelectric cogeneration drying system: Thermal modeling and case study

The demand for reducing fuel consumption and mitigating exhaust fumes accountable for the greenhouse effect push toward developing efficient energy recovery systems. Optimizing the heat recovery process can be achieved by adding multi-recovery stages. In this frame, the present work suggests a new multi-stage recovery system for heating water and air and generating electricity. The concept of the system is applied to the exhaust gases of a chimney. A complete thermal modeling of the system is drawn. Then a case study is carried out for three different fed fuels (diesel, coal, wood). The results show that when diesel is used water temperature achieved 351 K and 240 W electric power is generated. Moreover, a 0.16 m2 heat recovery heat exchanger area is required to heat air to 363 K at an air flow rate of 0.0076 kg/s. Such system can recover up to 84% of the energy lost to the environment when wood is utilized as a fed fuel

Connexin Expression and Gap Junctional Coupling in Human Cumulus Cells: Contribution to Embryo Quality

Gap junctional coupling among cumulus cells is important for oogenesis since its deficiency in mice leads to impaired folliculogenesis. Multiple connexins (Cx), the subunits of gap junction channels, have been found within ovarian follicles in several species but little is known about the connexins in human follicles. The aim of this study was to determine which connexins contribute to gap junctions in human cumulus cells and to explore the possible relationship between connexin expression and pregnancy outcome from in vitro fertilization (IVF). Cumulus cells were obtained from IVF patients undergoing intracytoplasmic sperm injection (ICSI). Connexin expression was examined by RT-PCR and confocal microscopy. Cx43 was quantified by immunoblotting and gap junctional coupling was measured by patch-clamp electrophysiology. All but five of 20 connexin mRNAs were detected. Of the connexin proteins detected, Cx43 forms numerous gap junction-like plaques but Cx26, Cx30, Cx30.3, Cx32, and Cx40 appeared to be restricted to the cytoplasm. The strength of gap junctional conductance varied between patients and was significantly and positively correlated with Cx43 level, but neither was correlated with patient age. Interestingly, Cx43 level and intercellular conductance were positively correlated with embryo quality as judged by cleavage rate and morphology, and were significantly higher in patients who became pregnant than in those who did not. Thus, despite the presence of multiple connexins, Cx43 is a major contributor to gap junctions in human cumulus cells and its expression level may influence pregnancy outcome after ICSI

DESIGN AND IMPLEMENTATION OF A TRANSPARENT SECURE LAN

Many attacks may be carried out against communications in Local Area Networks (LANs). However, these attacks can be prevented, or detected, by providing confidentiality, authentication, and data integrity security services to the exchanged data. This paper introduces a security system that protects a LAN from security attacks. On each host in the protected LAN, the security system transparently intercepts each outbound IP (Internet Protocol) packet, and inserts a crypto header between the packet IP header and payload. This header is used to detect any modification to the content of the packet in transit, and to detect replayed packets. Then, the system encrypts the IP packet payload and some fields of the inserted crypto header. On the other hand, the system transparently intercepts each inbound IP packet, decrypts its encrypted portions, and then uses its crypto header to authenticate the packet. If the packet is properly authenticated, thesystem indicates it to upper protocols. To be transparent to applications, the security system part that processes inbound and outbound IP packets was implemented as a NDIS (Network Driver Interface Specification) intermediate driver that resides between the LLC (Logical Link Control) and MAC (Medium Access Control) data link sublayers