On counting permutations by pairs of congruence classes of major index

For a fixed positive integer n, let S_n denote the symmetric group of n! permutations on n symbols, and let maj(sigma) denote the major index of a permutation sigma. For positive integers k<m not greater than n and non-negative integers i and j, we give enumerative formulas for the cardinality of the set of permutations sigma in S_n with maj(sigma) congruent to i mod k and maj(sigma^(-1)) congruent to j mod m. When m divides n-1 and k divides n, we show that for all i,j, this cardinality equals (n!)/(km).Comment: 8 page

Molecular Communication for Coordinated Seed and Fruit Development: What Can We Learn from Auxin and Sugars?

Seed development in flowering plants is a critical part of plant life for successful reproduction. The formation of viable seeds requires the synchronous growth and development of the fruit and the three seed structures: the embryo, the endosperm, the seed coat. Molecular communication between these tissues is crucial to coordinate these developmental processes. The phytohormone auxin is a significant player in embryo, seed and fruit development. Its regulated local biosynthesis and its cell-to-cell transport capacity make of auxin the perfect candidate as a signaling molecule to coordinate the growth and development of the embryo, endosperm, seed and fruit. Moreover, newly formed seeds need nutrients and form new carbon sink, generating high sugar flow from vegetative tissues to the seeds. This review will discuss how auxin and sugars may be considered as signaling molecules to coordinate seed and fruit development

Ultrasound-Guided Block of the Sciatic and the Femoral Nerves in Rabbits-A Descriptive Anatomical Study.

The rabbit is a popular animal model for human biomechanical research involving surgery on the hind limb. Mortality is higher in rabbits when undergoing general anesthesia compared to dogs and cats. Moreover, due to their nature as prey animals, rabbits have a tendency to hide signs of pain, making it challenging to detect discomfort at an early stage. Incorporating regional anesthesia into an anesthetic protocol can greatly reduce the requirements for systemic anesthetic and analgesic drugs, thereby minimizing associated side effects. In other species, a block of the sciatic (ScN) and the femoral nerves (FN) is usually applied in patients undergoing hind limb surgery. In phase 1 of this study, the ScN and the FN have been localized and an appropriate approach has been evaluated under sonographic guidance. In phase 2, a mixture of new methylene blue and lidocaine have been administered to the ScN and the FN in 10 cadavers (20 hind limbs). Staining of the nerves was evaluated by dissection. Ultrasonographically, the ScN appeared as a binocular structure surrounded by a hyperechoic rim. The FN appeared as a hypoechoic structure in the dorsal part of the iliopsoas muscle (IPM), becoming hyperechoic/honey-comb-like in the ventral part. Both nerves could be successfully stained in all animals over a median length of 2.3 cm which was considered effective. This technique allows feasible and accurate access to block the ScN and the FN and may lead to successful analgesia in rabbits undergoing hind limb surgery

Legal Obligations Toward the Post-Secondary Learning Disabled Student

This article will deal with the legal obligation of institutions of higher learning to provide appropriate services to their learning disabled students

Restoring Trust in Corporate Directors: The Disney Standard and the New Good Faith

The purpose of this Article is to explore the parameters and potential impact of the good faith standard articulated in Disney V and clarified in Stone. Part I begins with a brief review of the historical impact of the tension between entrepreneurial freedom and managerial accountability, and Part II explains why the Disney standard differs significantly from the traditional understanding of good faith as the absence of subjective bad faith. Part III points out that the court’s use of the language of bad faith to articulate the new good faith may undercut the effectiveness of the standard. It urges further clarification of the difference between the absence of good faith and the presence of bad faith to ensure that the Disney standard will not be reduced to a mere semantic variation on the traditional duty of loyalty applicable only in the presence of improper—i.e., subjectively “bad”—motivation. Finally, Part IV examines the Disney standard’s potential to serve as a vehicle for restoring trust in corporate directors and argues that the “new” good faith has the capacity to serve this important function, but only if the courts utilize the doctrine to require corporate directors to engage actively in oversight of the business and affairs of the entities entrusted to them. In the words of Chancellor Chandler, where corporate directors consciously disregard their duties, “the law must be strong enough to intervene against abuse of trust.

Transcriptional control of Arabidopsis seed development

Seed development is a complex process that proceeds through sequences of events regulated by the interplay of various genes, prominent among them being the transcription factors (TFs). The members of WOX, HD-ZIP III, ARF, and CUC families have a preferential role in embryonic patterning. While WOX TFs are required for initiating body axis, HD-ZIP III TFs and CUCs establish bilateral symmetry and SAM. And ARF5 performs a major role during embryonic root, ground tissue, and vasculature development. TFs such as LEC1, ABI3, FUS3, and LEC2 (LAFL) are considered the master regulators of seed maturation. Furthermore, several new TFs involved in seed storage reserves and dormancy have been identified in the last few years. Their association with those master regulators has been established in the model plant Arabidopsis. Also, using chromatin immunoprecipitation (ChIP) assay coupled with transcriptomics, genome-wide target genes of these master regulators have recently been proposed. Many seed-specific genes, including those encoding oleosins and albumins, have appeared as the direct target of LAFL. Also, several other TFs act downstream of LAFL TFs and perform their function during maturation. In this review, the function of different TFs in different phases of early embryogenesis and maturation is discussed in detail, including information about their genetic and molecular interactors and target genes. Such knowledge can further be leveraged to understand and manipulate the regulatory mechanisms involved in seed development. In addition, the genomics approaches and their utilization to identify TFs aiming to study embryo development are discussed.Seed development is a complex process that proceeds through sequences of events regulated by the interplay of various genes, prominent among them being the transcription factors (TFs). The members of WOX, HD-ZIP III, ARF, and CUC families have a preferential role in embryonic patterning. While WOX TFs are required for initiating body axis, HD-ZIP III TFs and CUCs establish bilateral symmetry and SAM. And ARF5 performs a major role during embryonic root, ground tissue, and vasculature development. TFs such as LEC1, ABI3, FUS3, and LEC2 (LAFL) are considered the master regulators of seed maturation. Furthermore, several new TFs involved in seed storage reserves and dormancy have been identified in the last few years. Their association with those master regulators has been established in the model plant Arabidopsis. Also, using chromatin immunoprecipitation (ChIP) assay coupled with transcriptomics, genome-wide target genes of these master regulators have recently been proposed. Many seed-specific genes, including those encoding oleosins and albumins, have appeared as the direct target of LAFL. Also, several other TFs act downstream of LAFL TFs and perform their function during maturation. In this review, the function of different TFs in different phases of early embryogenesis and maturation is discussed in detail, including information about their genetic and molecular interactors and target genes. Such knowledge can further be leveraged to understand and manipulate the regulatory mechanisms involved in seed development. In addition, the genomics approaches and their utilization to identify TFs aiming to study embryo development are discussed

Vécu et contraintes lors de l'application d'une nouvelle approche pédagogique: Une étude de cas québécoise en comptabilité.

This paper presents the experience of faculty members of the accounting department at Université Laval in designing and implementing a new curriculum. These changes have resulted from the new requirements of the profession as well as the growing gap between employers' expectations and skills and professional attitudes of graduating accounting students. In addition to presenting the context of these changes, the paper discusses some of the difficulties faced during the implementation of the new curriculum and, more importantly, those faced when introducing a new teaching approach. The new curriculum is focused on a collaborative approach whereby student participation is solicited. However, several difficulties have been met during the implementation. For instance, faculty members face a higher level of uncertainty in the classroom and must devote more time in developing teaching material. Students' perceptions, obtained through focus groups, were that the new program did not prepare them properly and that some courses were not useful. Throughout the paper, we offer some strategies that can be used to minimize the impact of the difficulties faced when implementing a new teaching approach that can overturn previously firmly held beliefs about appropriate pedagogical methods.Cet article présente l'expérience vécue au Département des sciences comptables de l'Université Laval lors de la réforme des cours du baccalauréat. Cette réforme s'explique par les changements importants qui bouleversent la profession comptable et par l'écart grandissant entre les besoins des employeurs et les compétences et les attitudes professionnelles des finissants en comptabilité. En plus de présenter le contexte dans lequel s'est effectué la réforme, l'article fait état des obstacles rencontrés tout au long des modifications apportées au contenu des cours et, surtout, de l'implantation d'une nouvelle approche pédagogique. Le nouveau programme est centré sur une approche collaborative par problèmes où la participation de l'étudiant est fortement sollicitée. Un tel changement ne s'est pas fait sans rencontrer de nombreux obstacles. Par exemple, l'approche choisie a créé un niveau d'incertitude élevé chez les professeurs et a exigé, de leur part, d'allouer une partie importante de leur allouée au développement de matériel didactique. La perception des étudiants, obtenue à l'aide d'entrevues de groupe, était que les cours ne les préparaient pas adéquatement et que parfois, ils étaient inutiles. Nous proposons certains éléments de solution qui peuvent réduire l'impact des problèmes rencontrés lors de l'implantation d'une nouvelle approche pédagogique qui bouleverse certaines conceptions fortement ancrées

Association of Cumulative Lead Exposure with Parkinson's Disease

BACKGROUND. Research using reconstructed exposure histories has suggested an association between heavy metal exposures, including lead, and Parkinson's disease (PD), but the only study that used bone lead, a biomarker of cumulative lead exposure, found a nonsignificant increase in risk of PD with increasing bone lead. OBJECTIVES. We sought to assess the association between bone lead and PD. METHODS. Bone lead concentrations were measured using 109Cd excited K-shell X-ray fluorescence from 330 PD patients (216 men, 114 women) and 308 controls (172 men, 136 women) recruited from four clinics for movement disorders and general-community cohorts. Adjusted odds ratios (ORs) for PD were calculated using logistic regression. RESULTS. The average age of cases and controls at bone lead measurement was 67 (SD = 10) and 69 (SD = 9) years of age, respectively. In primary analyses of cases and controls recruited from the same groups, compared with the lowest quartile of tibia lead, the OR for PD in the highest quartile was 3.21 [95% confidence interval (CI), 1.17-8.83]. Results were similar but slightly weaker in analyses restricted to cases and controls recruited from the movement disorders clinics only (fourth-quartile OR = 2.57; 95% CI, 1.11-5.93) or when we included controls recruited from sites that did not also contribute cases (fourth-quartile OR = 1.91; 95% CI, 1.01-3.60). We found no association with patella bone lead. CONCLUSIONS. These findings, using an objective biological marker of cumulative lead exposure among typical PD patients seen in our movement disorders clinics, strengthen the evidence that cumulative exposure to lead increases the risk of PD.National Institutes of Health (R01-ES010798, K01-ES01265