Etude préliminaire de l’ichtyotoxicité des feuilles et tourteau de Balanites aegyptiaca et de tourteau de thé (Camellia sp) en vue de leurs utilisations comme piscicide d’aménagement des étangs piscicoles

Les feuilles et le tourteau de Balanites aegyptiaca et le tourteau de thé ont été étudiés pour leur toxicité au tilapia (Oreochromis niloticus). Les résultats ont notamment montré qu’avec le tourteau de B. aegyptiaca, à la concentration de 25 mg/l, 50% des poissons meurent en 2 heures 47 minutes et 100% meurent en 3 heures 10 minutes. Ces résultats sont de même ordre de grandeur que ceux obtenus avec le tourteau de thé pour lequel 50% des poissons meurent en 2 heures 37 minutes et 100% en 3 heures 23 minutes avec la concentration de 25 mg/l. Avec les macérés des feuilles de B. aegyptiaca, il faut jusqu’à 900 mg/l pour obtenir 50% de morts en 3 heures 37 minutes et 100% de morts en 4 heures 85 minutes. La réalisation des réactions de caractérisation a révélé la présence de 12 groupes chimiques dont des saponisides dans les feuilles de B. aegyptiaca qui pourraient expliquer cette performance d’ichtyotoxicité. Ces résultats suggèrent que le tourteau de B. aegyptiaca pourrait remplacer le tourteau de thé (ou saponine) comme piscicide dans les aménagements piscicoles.Mots clés: Balanites aegyptiaca, ichtyotoxique, feuilles, tourteaux, thé, tilapia d’élevag

The Quantum Reduced Action In Higher Dimensions

The solution with respect to the reduced action of the one-dimensional stationary quantum Hamilton-Jacobi equation is well known in the literature. The extension to higher dimensions in the separated variable case was proposed in contradictory formulations. In this paper we provide new insights into the construction of the reduced action. In particular, contrary to the classical mechanics case, we analytically show that the reduced action constructed as a sum of one variable functions does not contain a complete information about the quantum motion. In the same context, we also make some observations about recent results concerning quantum trajectories. Finally, we will examine the conditions in which microstates appear even in the case where the wave function is complex.Comment: 12 pages, no figur

Etude de la toxicité des feuilles du pommier de Sodome du Sénégal et du tourteau de graines de thé chez le tilapia du Nil en aménagement piscicole

Les toxicités des feuilles du pommier de Sodome du Sénégal (Calotropis procera) et du tourteau de graines de thé (Camellia sp) chez le tilapia du Nil (Oreochromis niloticus) en pisciculture ont été étudiées. La réalisation des réactions de caractérisation chimique a révélé la forte présence des coumarines et d’anthocyanes mais seulement des traces de saponosides dans les feuilles de C. procera. Cependant elle n’a pas révélé la présence d’autres groupes particulièrement ichtyotoxiques. Les résultats ont notamment montré qu’avec les macérés aqueux de feuilles fraîches du pommier de Sodome du Sénégal, il faut une concentration de 10000 mg/l pour que 50% des poissons meurent en 4 heures 10 mn et 100% meurent en 5 heures 59 mn. Avec le tourteau de graines de thé, 50% de morts des poissons sont obtenus en 2 heures 37 mn et 100% de morts en 3 heures 23 mn avec la concentration de 25 mg/l. Ceci pourrait expliquer la relative faible ichtyotoxicité des macérés aqueux de feuilles du pommier de Sodome du Sénégal comparée à celle du tourteau de thé.Mots clés : Feuilles de Calotropis procera, ichtyotoxicité, tourteau, graines Camellia sp, tilapia du Nile d’élevage

Optimality of private quantum channels

We addressed the question of optimality of private quantum channels. We have shown that the Shannon entropy of the classical key necessary to securely transfer the quantum information is lower bounded by the entropy exchange of the private quantum channel $\cal E$ and von Neumann entropy of the ciphertext state $\varrho^{(0)}$. Based on these bounds we have shown that decomposition of private quantum channels into orthogonal unitaries (if exists) is optimizing the entropy. For non-ancillary single qubit PQC we have derived the optimal entropy for arbitrary set of plaintexts. In particular, we have shown that except when the (closure of the) set of plaintexts contains all states, one bit key is sufficient. We characterized and analyzed all the possible single qubit private quantum channels for arbitrary set of plaintexts. For the set of plaintexts consisting of all qubit states we have characterized all possible approximate private quantum channels and we have derived the relation between the security parameter and the corresponding minimal entropy.Comment: no commen

Fair and optimistic quantum contract signing

We present a fair and optimistic quantum contract signing protocol between two clients that requires no communication with the third trusted party during the exchange phase. We discuss its fairness and show that it is possible to design such a protocol for which the probability of a dishonest client to cheat becomes negligible, and scales as N^{-1/2}, where N is the number of messages exchanged between the clients. Our protocol is not based on the exchange of signed messages: its fairness is based on the laws of quantum mechanics. Thus, it is abuse-free, and the clients do not have to generate new keys for each message during the Exchange phase. We discuss a real-life scenario when the measurement errors and qubit state corruption due to noisy channels occur and argue that for real, good enough measurement apparatus and transmission channels, our protocol would still be fair. Our protocol could be implemented by today's technology, as it requires in essence the same type of apparatus as the one needed for BB84 cryptographic protocol. Finally, we briefly discuss two alternative versions of the protocol, one that uses only two states (based on B92 protocol) and the other that uses entangled pairs, and show that it is possible to generalize our protocol to an arbitrary number of clients.Comment: 11 pages, 2 figure

Study of 12C(α,γ)16O reaction via the transfer reaction 12C(7Li,t)16O

International audienceThe 12C(a,g )16O reaction plays an important role in helium burning in massive stars and their evolution. However, despite many experimental studies, the low-energy cross section of 12C(a,g )16O remains highly uncertain. The extrapolation of the measured cross sections to stellar energies (E=300 keV) is made difficult by the presence of the two sub-threshold states at 6.92 (2+) and 7.12 (1−) MeV of 16O. In order to further investigate the contribution of these twosubthreshold resonances to the 12C(a,g )16O cross section, we performed a new determination of the a-reduced widths of the 6.92 and 7.12 MeV of 16O via a measurement of the transfer reaction 12C(7Li,t)16O at two incident energies, 34 and 28 MeV. The measured and calculated differential cross sections are presented as well as the obtained spectroscopic factors and the a-reduced widths for the 2+ and 1− sub-threshold states and their effect on the R-matrix calculations of 12C(a,g )16O

A possible Reinterpretation of Einstein's Equations

In this paper, we first review Huei's formulation in which it is shown that the linearized Einstein equations can be written in the same form as the Maxwell equations. We eliminate some imperfections like the scalar potential which is ill linked to the electric-type field, the Lorentz-type force which is obtained with a time independence restriction and the undesired factor 4 which appears in the magnetic-type part. Second, from these results and in the light of a recent work by C.C. Barros, we propose an extension of the equivalence principle and we suggest a new interpretation for Einstein's equations by showing that the electromagnetic Maxwell equations can be derived from a new version of Einstein's ones.Comment: 11 pages, no figure

⁸⁹Zr-Trastuzumab PET/CT Imaging of HER2-Positive Breast Cancer for Predicting Pathological Complete Response after Neoadjuvant Systemic Therapy:A Feasibility Study

Background: Approximately 20% of invasive ductal breast malignancies are human epidermal growth factor receptor 2 (HER2)-positive. These patients receive neoadjuvant systemic therapy (NAT) including HER2-targeting therapies. Up to 65% of patients achieve a pathological complete response (pCR). These patients might not have needed surgery. However, accurate preoperative identification of a pCR remains challenging. A radiologic complete response (rCR) on MRI corresponds to a pCR in only 73% of patients. The current feasibility study investigates if HER2-targeted PET/CT-imaging using Zirconium-89 (89Zr)-radiolabeled trastuzumab can be used for more accurate NAT response evaluation. Methods: HER2-positive breast cancer patients scheduled to undergo NAT and subsequent surgery received a 89Zr-trastuzumab PET/CT both before (PET/CT-1) and after (PET/CT-2) NAT. Qualitative and quantitative response evaluation was performed. Results: Six patients were enrolled. All primary tumors could be identified on PET/CT-1. Four patients had a pCR and two a pathological partial response (pPR) in the primary tumor. Qualitative assessment of PET/CT resulted in an accuracy of 66.7%, compared to 83.3% of the standard-of-care MRI. Quantitative assessment showed a difference between the SUVR on PET/CT-1 and PET/CT-2 (ΔSUVR) in patients with a pPR and pCR of −48% and −90% (p = 0.133), respectively. The difference in tumor-to-blood ratio on PET/CT-1 and PET/CT-2 (ΔTBR) in patients with pPR and pCR was −79% and −94% (p = 0.133), respectively. Three patients had metastatic lymph nodes at diagnosis that were all identified on PET/CT-1. All three patients achieved a nodal pCR. Qualitative assessment of the lymph nodes with PET/CT resulted in an accuracy of 66.7%, compared to 50% of the MRI. Conclusions: NAT response evaluation using 89Zr-trastuzumab PET/CT is feasible. In the current study, qualitative assessment of the PET/CT images is not superior to standard-of-care MRI. Our results suggest that quantitative assessment of 89Zr-trastuzumab PET/CT has potential for a more accurate response evaluation of the primary tumor after NAT in HER2-positive breast cancer.</p

⁸⁹Zr-Trastuzumab PET/CT Imaging of HER2-Positive Breast Cancer for Predicting Pathological Complete Response after Neoadjuvant Systemic Therapy:A Feasibility Study

Background: Approximately 20% of invasive ductal breast malignancies are human epidermal growth factor receptor 2 (HER2)-positive. These patients receive neoadjuvant systemic therapy (NAT) including HER2-targeting therapies. Up to 65% of patients achieve a pathological complete response (pCR). These patients might not have needed surgery. However, accurate preoperative identification of a pCR remains challenging. A radiologic complete response (rCR) on MRI corresponds to a pCR in only 73% of patients. The current feasibility study investigates if HER2-targeted PET/CT-imaging using Zirconium-89 (89Zr)-radiolabeled trastuzumab can be used for more accurate NAT response evaluation. Methods: HER2-positive breast cancer patients scheduled to undergo NAT and subsequent surgery received a 89Zr-trastuzumab PET/CT both before (PET/CT-1) and after (PET/CT-2) NAT. Qualitative and quantitative response evaluation was performed. Results: Six patients were enrolled. All primary tumors could be identified on PET/CT-1. Four patients had a pCR and two a pathological partial response (pPR) in the primary tumor. Qualitative assessment of PET/CT resulted in an accuracy of 66.7%, compared to 83.3% of the standard-of-care MRI. Quantitative assessment showed a difference between the SUVR on PET/CT-1 and PET/CT-2 (ΔSUVR) in patients with a pPR and pCR of −48% and −90% (p = 0.133), respectively. The difference in tumor-to-blood ratio on PET/CT-1 and PET/CT-2 (ΔTBR) in patients with pPR and pCR was −79% and −94% (p = 0.133), respectively. Three patients had metastatic lymph nodes at diagnosis that were all identified on PET/CT-1. All three patients achieved a nodal pCR. Qualitative assessment of the lymph nodes with PET/CT resulted in an accuracy of 66.7%, compared to 50% of the MRI. Conclusions: NAT response evaluation using 89Zr-trastuzumab PET/CT is feasible. In the current study, qualitative assessment of the PET/CT images is not superior to standard-of-care MRI. Our results suggest that quantitative assessment of 89Zr-trastuzumab PET/CT has potential for a more accurate response evaluation of the primary tumor after NAT in HER2-positive breast cancer.</p

A Threshold Value for the Time Delay to TB Diagnosis

The original publication is available at http:/www.plosone.orgIncludes bibliographyBackgound. In many communities where TB occurs at high incidence, the major force driving the epidemic is transmission. It is plausible that the typical long delay from the onset of infectious disease to diagnosis and commencement of treatment is almost certainly the major factor contributing to the high rate of transmission. Methodology/Principal Findings. This study is confined to communities which are epidemiologically relatively isolated and which have low HIV incidence. The consequences of delays to diagnosis are analyzed and the existence of a threshold delay value is demonstrated. It is shown that unless a sufficient number of cases are detected before this threshold, the epidemic will escalate. The method used for the analysis avoids the standard computer integration of systems of differential equations since the intention is to present a line of reasoning that reveals the essential dynamics of an epidemic in an intuitively clear way that is nevertheless quantitatively realistic. Conclusions/Significance. The analysis presented here shows that typical delays to diagnosis present a major obstacle to the control of a TB epidemic. Control can be achieved by optimizing the rapid identification of TB cases together with measures to increase the threshold value. A calculated and aggressive program is therefore necessary in order to bring about a reduction in the prevalence of TB in a community by decreasing the time to diagnosis in all its ramifications. Intervention strategies to increase the threshold value relative to the time to diagnosis and which thereby decrease disease incidence are discussed. © 2007 Uys et al.Publishers' Versio