The third moment of quadratic Dirichlet L-functions

We study the third moment of quadratic Dirichlet L-functions, obtaining an error term of size $O(X^{3/4 + \varepsilon})$.Comment: 27 pages. v2: modified a remark on p.

Pelvic floor disorders in gynecological malignancies. An overlooked problem?

Cervical, endometrial, ovarian, vulvar, and vaginal cancers affect women of a broad age spectrum. Many of these women are still sexually active when their cancer is diagnosed. Treatment options for gynecological malignancies, such as gynecological surgery, radiation, and chemotherapy, are proven risk factors for pelvic floor dysfunction. The prevalence of urinary incontinence, fecal incontinence, and sexual dysfunction before cancer treatment is still unclear. Hypotheses have been raised in the literature that these manifestations could represent early symptoms of pelvic cancers, but most remain overlooked even in cancer surviving patients. The primary focus of therapy is always cancer eradication, but as oncological and surgical treatment options become more successful, the number of cancer survivors increases. The quality of life of patients with gynecological cancers often remains an underrated subject. Pelvic floor disorders are not consistently reported by patients and are frequently overlooked by many clinicians. In this brief review we discuss the importance of pelvic floor dysfunction in patients with gynecological malignant tumors

Pheochromocytoma – clinical manifestations, diagnosis and current perioperative management

Pheochromocytoma is a neuroendocrine tumor characterized by the excessive production of catecholamines (epinephrine, norepinephrine, and dopamine). The diagnosis is suspected due to hypertensive paroxysms, associated with vegetative phenomena, due to the catecholaminergic hypersecretion. Diagnosis involves biochemical tests that reveal elevated levels of catecholamine metabolites (metanephrine and normetanephrine). Functional imaging, such as 123I-metaiodobenzylguanidine scintigraphy (123I-MIBG), has increased specificity in identifying the catecholamine-producing tumor and its metastases. The gold-standard treatment for patients with pheochromocytoma is represented by the surgical removal of the tumor. Before surgical resection, it is important to optimize blood pressure and intravascular volume in order to avoid negative hemodynamic events

LARS-like symptoms in the general population may suggest the significance of postoperative functional problems and emotional implications of rectal surgery

Background & Aim. Sphincter-saving rectal surgery is prone to cause changes in bowel function associated with Low Anterior Resection Syndrome (LARS). Our aim was to assess LARS-like symptoms within a population of 50-80-year old in order to understand the functional disturbances and emotional impact of LARS. Materials and methods: We used a questionnaire to evaluate LARS with the following categories of symptoms: flatulence control, anal incontinence, frequency, clustering and urgency of the stools, and the psycho-emotional impact created by the presence of these symptoms. We calculated the severity of LARS on 343 responders. Results. The average age of the responders (57.4% females) was 60 years. Overall, 48.1% of those questioned had no LARS-associated symptoms, while the rest presented either minor (39.9%) or major (12%) LARS-like symptomatology according to the assessment scale. Women have a higher relative risk (1.32) of having minor or major LARS. The frequency of stools did not correlate with the overall LARS score. The psycho-emotional impact was mostly influenced by the presence of incontinence (p=0.001) and urgency (p=0.05). Discussions. The study highlights the need to integrate the initial status of patients into the overall quantification of the effects of surgery on the quality of life. Age does not influence the prevalence of LARS, but symptoms seem more prevalent in women. The psycho-emotional impact is relevant to the general population, so explanations given during the informed consent and accurate description of potential consequences of surgical intervention increase compliance to ensure better post-operative control of the symptomatology. Conclusions. Deriving a normative LARS-like score may alter the interpretation and discussion of LARS scores for future rectal cancer patients, and it also provides a better understanding of the emotional impact of such symptoms on certain population subsets or cultural groups

The importance of early arthritis in patients with rheumatoid arthritis

Rheumatoid arthritis (RA) is a systemic inflammatory disorder that manifests predominantly in the synovial joint, where it causes a chronic inflammatory process, leading to early osteoarticular destructions. These destructions are progressive and irreversible, generating a significant functional deficiency. During the last years, the diagnostic approach of RA has focused on early arthritis. Early arthritis can develop into established RA or another established arthropathy, like systemic lupus erythematosus or psoriatic arthritis. It can have a spontaneous resolution or may remain undifferentiated for indefinite periods of time. The management of early arthritis has changed considerably in the past few years, under the influence of new concepts of diagnosis and new effective therapies. The treatment goal of early arthritis should now be the clinical remission and prevention of joint destruction. Methotrexate is the first line of therapy, used to treat early arthralgia and to reverse or limit impending exacerbation to RA. Biological treatment is used as a second line therapy in patients with severe disease who do not respond or have a contraindication to disease-modifying antirheumatic drugs (DMARDs). Patients with early arthritis should usually be identified and directed to rheumatologists to confirm the presence of arthritis, and to establish the correct diagnosis plus to initiate the proper treatment strategies

Weyl group multiple Dirichlet series constructed from quadratic characters

We construct multiple Dirichlet series in several complex variables whose coefficients involve quadratic residue symbols. The series are shown to have an analytic continuation and satisfy a certain group of functional equations. These are the first examples of an infinite collection of unstable Weyl group multiple Dirichlet series in greater than two variables.Comment: incorporated referee's comment

A nonlinear spring mechanism incorporating a bistable composite plate for vibration isolation

The High Static Low Dynamic Stiffness (HSLDS) concept is a design strategy for a nonlinear anti-vibration mount that seeks to increase isolation by lowering the natural frequency of the mount whilst maintaining the same static load bearing capacity. It has previously been proposed that an HSLDS mount could be implemented by connecting linear springs in parallel with the transverse flexure of a composite bistable plate — a plate that has two stable shapes between which it may snap. Using a bistable plate in this way will lead to lightweight and efficient designs of HSLDS mounts. This paper experimentally demonstrates the feasibility of this idea. Firstly, the quasi-static force–displacement curve of a mounted bistable plate is determined experimentally. Then the dynamic response of a nonlinear mass–spring system incorporating this plate is measured. Excellent agreement is obtained when compared to theoretical predictions based on the measured force–displacement curve, and the system shows a greater isolation region and a lower peak response to base excitation than the equivalent linear system

Approximation of the critical buckling factor for composite panels

This article is concerned with the approximation of the critical buckling factor for thin composite plates. A new method to improve the approximation of this critical factor is applied based on its behavior with respect to lamination parameters and loading conditions. This method allows accurate approximation of the critical buckling factor for non-orthotropic laminates under complex combined loadings (including shear loading). The influence of the stacking sequence and loading conditions is extensively studied as well as properties of the critical buckling factor behavior (e.g concavity over tensor D or out-of-plane lamination parameters). Moreover, the critical buckling factor is numerically shown to be piecewise linear for orthotropic laminates under combined loading whenever shear remains low and it is also shown to be piecewise continuous in the general case. Based on the numerically observed behavior, a new scheme for the approximation is applied that separates each buckling mode and builds linear, polynomial or rational regressions for each mode. Results of this approach and applications to structural optimization are presented