Constraints and Soliton Solutions for the KdV Hierarchy and AKNS Hierarchy

It is well-known that the finite-gap solutions of the KdV equation can be generated by its recursion operator.We generalize the result to a special form of Lax pair, from which a method to constrain the integrable system to a lower-dimensional or fewer variable integrable system is proposed. A direct result is that the $n$-soliton solutions of the KdV hierarchy can be completely depicted by a series of ordinary differential equations (ODEs), which may be gotten by a simple but unfamiliar Lax pair. Furthermore the AKNS hierarchy is constrained to a series of univariate integrable hierarchies. The key is a special form of Lax pair for the AKNS hierarchy. It is proved that under the constraints all equations of the AKNS hierarchy are linearizable.Comment: 12 pages, 0 figur

Le mouvement pour la démocratie à Hong Kong Une décennie perdue ?

En 2007, le mouvement pour la démocratie à Hong Kong n’est pas au mieux de sa forme. Le suffrage universel ne sera sans doute pas instauré, même à l’échéance de 2012. La pérennité du mouvement est toutefois assurée par deux élémentsł: d’une part, toutes les parties concernées ont conscience de la nécessité de maintenir l’État de droit et la liberté d’information, d’autre part, une majorité d’électeurs hongkongais souhaite conserver un minimum d’équilibre des pouvoirs.

Le mouvement pour la démocratie à Hong Kong Une décennie perdue ?

En 2007, le mouvement pour la démocratie à Hong Kong n’est pas au mieux de sa forme. Le suffrage universel ne sera sans doute pas instauré, même à l’échéance de 2012. La pérennité du mouvement est toutefois assurée par deux élémentsł: d’une part, toutes les parties concernées ont conscience de la nécessité de maintenir l’État de droit et la liberté d’information, d’autre part, une majorité d’électeurs hongkongais souhaite conserver un minimum d’équilibre des pouvoirs.

David Shambaugh, China’s Communist Party: Atrophy and Adaptation

L’ouvrage de David Shambaugh se concentre sur le Parti communiste chinois (PCC) en tant qu’institution. Il tente de répondre aux questions clés suivantes : (a) pourquoi le PCC at- il pu rester au pouvoir ? (b) quelles leçons le PCC a-t-il tiré de l’effondrement d’autres partis communistes dirigeants ? comment ces leçons ont-elles été appliquées en Chine depuis 1989 ? c) comment le PCC a-t-il analysé son propre environnement ? et d) se maintiendra-t-il en tant que parti dirigeant en Chine ? Le..

David Shambaugh, China’s Communist Party: Atrophy and Adaptation

David Shambaugh’s volume concentrates on the Chinese Communist Party (CCP) as an institution. It attempts to answer the following key questions: (a) Why has the CCP survived in power? (b) What lessons has the CCP learned from the collapse of other ruling communist parties? How have these lessons been applied in China since 1989? (c) How has the CCP analyzed its own conditions? and, (d) Will it endure as the ruling party in China? Shambaugh argues that the CCP as an institution has been in a p..

PPARs and Tumor Microenvironment: The Emerging Roles of the Metabolic Master Regulators in Tumor Stromal-Epithelial Crosstalk and Carcinogenesis.

Peroxisome proliferator-activated receptors (PPARs) have been extensively studied for more than three decades. Consisting of three isotypes, PPARα, γ, and β/δ, these nuclear receptors are regarded as the master metabolic regulators which govern many aspects of the body energy homeostasis and cell fate. Their roles in malignancy are also increasingly recognized. With the growing interest in crosstalk between tumor stroma and epithelium, this review aims to highlight the current knowledge on the implications of PPARs in the tumor microenvironment. PPARγ plays a crucial role in the metabolic reprogramming of cancer-associated fibroblasts and adipocytes, coercing the two stromal cells to become substrate donors for cancer growth. Fibroblast PPARβ/δ can modify the risk of tumor initiation and cancer susceptibility. In endothelial cells, PPARβ/δ and PPARα are pro- and anti-angiogenic, respectively. Although the angiogenic role of PPARγ remains ambiguous, it is a crucial regulator in autocrine and paracrine signaling of cancer-associated fibroblasts and tumor-associated macrophages/immune cells. Of note, angiopoietin-like 4 (ANGPTL4), a secretory protein encoded by a target gene of PPARs, triggers critical oncogenic processes such as inflammatory signaling, extracellular matrix derangement, anoikis resistance and metastasis, making it a potential drug target for cancer treatment. To conclude, PPARs in the tumor microenvironment exhibit oncogenic activities which are highly controversial and dependent on many factors such as stromal cell types, cancer types, and oncogenesis stages. Thus, the success of PPAR-based anticancer treatment potentially relies on innovative strategies to modulate PPAR activity in a cell type-specific manner

Circulating human leucine-rich a-2-glycoprotein 1 mRNA and protein levels to detect acute appendicitis in patients with acute abdominal pain

Background Elevated levels of circulating plasma and urine leucine-rich-2-glycoprotein-1 (LRG1) protein has been found in patients with acute appendicitis (AA) and may be useful for diagnosis. This study aimed to investigate whether combined tests including circulating LRG1 mRNA levels improve the early diagnosis of AA. Methods Between December 2011 and October 2012, a prospective study was conducted on patients aged 18 years or older presenting to the ED with acute abdominal pain (< 7 days of symptom onset). Levels of whole blood LRG1 mRNA and plasma LRG1 protein taken from these patients within 24 h of arrival (mean 12.4 h) were analyzed. The primary outcome was AA. Results Eighty-four patients (40 (47.6%) with AA and 44 (52.4%) without AA; mean age 35 years; 41.6% males) were recruited. Median whole blood LRG1 mRNA and plasma LRG1 levels were higher in AA patients than in non-AA. Of 40 AA patients, 13 (32.5%) were diagnosed as complicated AA. In ROC analysis of LRG1 mRNA (normalized to GAPDH), LRG1 protein and Alvarado score for discriminating AA and non-AA, the areas under the curve (AUC) were 0.723, 0.742 and 0.805 respectively. The AUC of combination of normalized LRG1 mRNA, LRG1 protein and Alvarado score was 0.845. Conclusion A combination of modified whole blood LRG1 mRNA levels, plasma LRG1 protein and Alvarado score at the ED may be useful to diagnose simple and complicated AA from other causes of abdominal pain

Light-Front Approach for Pentaquark Strong Decays

Assuming the two diquark structure for the pentaquark state as advocated in the Jaffe-Wilczek model, we study the strong decays of light and heavy parity-even pentaquark states using the light-front quark model in conjunction with the spectator approximation. The narrowness of the Theta width is ascribed to the p-wave configuration of the diquark pair. Taking the Theta width as a benchmark, we estimate the rates of the strong decays Xi_{3/2}-- to Xi- pi-, Sigma- K-, Sigma_{5c}0 to D_s- p, D_{s0}*- p and Xi_{5c}0 to D_s- Sigma+, D_{s0}^{*-} Sigma+ with Sigma_{5c} Xi_{5c} being antisextet charmed pentaquarks and D_{s0}* a scalar strange charmed meson. The ratio of Gamma(P_c to Baryon D_{s0}*)/Gamma(P_c to Baryon D_s) is very useful for verifying the parity of the antisextet charmed pentaquark P_c. It is expected to be of order unity for an even parity P_c and much less than one for an odd parity pentaquark.Comment: 24 pages, 2 figure