The neurobiology of circadian rhythms

Purpose of review There is growing awareness of the importance of circadian rhythmicity in various research fields. Exciting developments are ongoing in the field of circadian neurobiology linked to sleep, food intake, and memory. With the current knowledge of critical ‘clock genes’ (genes found to be involved in the generation of circadian rhythms) and novel techniques for imaging cyclic events in brain and peripheral tissue, this field of research is rapidly expanding. We reviewed only some of the highlights of the past year, and placed these findings into a mutual circadian perspective. Recent findings Recent findings on the organization of the circadian clock systems are addressed, ranging from the retina to the suprachiasmatic nucleus and peripheral organs. Novel developments in sleep, food intake, and memory research linked to circadian aspects are discussed. Summary The neurobiology of circadian rhythms is pivotal to the orchestration of the temporal organization of an individual’s physiology and behavior. Endogenous circadian timing systems underlie coupling and uncoupling mechanisms of many neuronal and physiological processes, the latter possibly inducing health risks to the organism. The integration of sleep, food intake and memory in a circadian setting has clear potential as a systems neurobiology line of research.

Impact and application of electron shuttles on the redox (bio)transformation of contaminants : a review

During the last two decades, extensive research has explored the catalytic effects of different organic molecules with redox mediating properties on the anaerobic (bio)transformation of a wide variety of organic and inorganic compounds. The accumulated evidence points at a major role of electron shuttles in the redox conversion of several distinct contaminants, both by chemical and biological mechanisms. Many microorganisms are capable of reducing redox mediators linked to the anaerobic oxidation of organic and inorganic substrates. Electron shuttles can also be chemically reduced by electron donors commonly found in anaerobic environments (e.g. sulfide and ferrous iron). Reduced electron shuttles can transfer electrons to several distinct electron-withdrawing compounds, such as azo dyes, polyhalogenated compounds, nitroaromatics and oxidized metalloids, among others. Moreover, reduced molecules with redox properties can support the microbial reduction of electron acceptors, such as nitrate, arsenate and perchlorate. The aim of this review paper is to summarize the results of reductive (bio)transformation processes catalyzed by electron shuttles and to indicate which aspects should be further investigated to enhance the applicability of redox mediators on the (bio)transformation of contaminants.F.P. van der Zee thanks the Portuguese Fundaicao para a Ciencia e a Tecnologia for financial support (Grant SFRH/BPD/39086/2007). F. J. Cervantes greatly acknowledges a grant from Council of Science and Technology of Mexico (Grant SEP-CONACYT-C02-55045)

Discontinuities without discontinuity: The Weakly-enforced Slip Method

Tectonic faults are commonly modelled as Volterra or Somigliana dislocations in an elastic medium. Various solution methods exist for this problem. However, the methods used in practice are often limiting, motivated by reasons of computational efficiency rather than geophysical accuracy. A typical geophysical application involves inverse problems for which many different fault configurations need to be examined, each adding to the computational load. In practice, this precludes conventional finite-element methods, which suffer a large computational overhead on account of geometric changes. This paper presents a new non-conforming finite-element method based on weak imposition of the displacement discontinuity. The weak imposition of the discontinuity enables the application of approximation spaces that are independent of the dislocation geometry, thus enabling optimal reuse of computational components. Such reuse of computational components renders finite-element modeling a viable option for inverse problems in geophysical applications. A detailed analysis of the approximation properties of the new formulation is provided. The analysis is supported by numerical experiments in 2D and 3D.Comment: Submitted for publication in CMAM

Способ профилактики и лечения послеоперационного гипотиреоза путем аутотрансплантации ткани щитовидной железы

Мета роботи - розробка ефективного способу хірургічного лікування й профілактики післяопераційного гіпотиреозу. Запропоновано спосіб профілактики та лікування післяопераційного гіпотиреозу методом аутотрансплантації щитоподібної залози. Наведені результати демонструють простоту, доступність і безпеку цього методу. Результати та обговорення. Ступінь гормональної компенсації після тиреоїдєктомії з аутотрансплантацією тиреоїдної тканини залежить від загальної маси аутографа, ваги пацієнта. Лікування післяопераційного гіпотиреозу методом аутотрансплантації оксігенованої тиреоїдної тканини щитоподібної залози є ефективним, простим, легким у виконанні, економічно доступним та доцільним.The aim - is to develop an affective method of surgical treatment of a postoperation hypothyroidism. Material and methods. The method of prophylaxis and treatment of a hypothyroidism by autotransplantation of a thyroid tissue worked out. For correction of postsurgical hypothyroidism the autotransplantation of oxygenated thyroid gland was performed with the following clinical-laboratory dynamics. Good results after autotransplantation of a thyroid tissue demonstrate the the simplicity,availability,safety and cheapness of this method of prophylaxis and treatment of a postoperation hypothyroidism. Completeness of hormonal compensation after thyroidectomy with autotransplantation of a thyroid tissue depends on weight of autografts, body weight of patient. Treatment of postoperation hypothyroidism by autotransplantation of a thyroid tissue is effective, simple, easy implemented and cost effective

Whole body hyperthermia : the development of and experience with a clinical method

Whole body hyperthermia is one of the methods available for the treatment of malignant turrours with heat. At the Rotterdam Radio-Therapeutic Institute this method was investigated in 27 patients in a period of 3 1/2 years. This thesis describes the results of this investigation. The final conclusions from this study are: the technique used for induction of WBHT is clinically useful and its efficiency is comparable to the efficiencies mentioned by other authors Who use a technique of transcutaneous energy input; - WBHT at 41.8°C for 2 hours is effective, but has to be canbined with either radiotherapy or cherrotherapy to obtain a valuable effect for the patient; In sane cases the treatment may unexpectedly induce severe toxicity. Therefore research should continue with regard to better alternatives such as local hyperthennia and/or a safer method of WBHI'-induction

The Discrete-Dual Minimal-Residual Method (DDMRes) for Weak Advection-Reaction Problems in Banach Spaces

© 2019 Walter de Gruyter GmbH, Berlin/Boston 2019. We propose and analyze a minimal-residual method in discrete dual norms for approximating the solution of the advection-reaction equation in a weak Banach-space setting. The weak formulation allows for the direct approximation of solutions in the Lebesgue Lp, 1 < p < ∞. The greater generality of this weak setting is natural when dealing with rough data and highly irregular solutions, and when enhanced qualitative features of the approximations are needed. We first present a rigorous analysis of the well-posedness of the underlying continuous weak formulation, under natural assumptions on the advection-reaction coefficients. The main contribution is the study of several discrete subspace pairs guaranteeing the discrete stability of the method and quasi-optimality in L p {L^{p}}, and providing numerical illustrations of these findings, including the elimination of Gibbs phenomena, computation of optimal test spaces, and application to 2-D advection

Wnt/Β-Catenin and Sex Hormone Signaling In Endometrial Homeostasis and Cancer

A delicate balance between estrogen and progestagen signaling underlies proper functioning of the female reproductive tract and, in particular, the monthly re- and degenerative phases characteristic of the menstrual cycle. Here, we propose that the canonical Wnt/β-catenin signaling pathway may underlie this finely tuned hormonal equilibrium in endometrial homeostasis and, upon its constitutive activation, lead to neoplastic transformation of the endometrium. During the menstrual cycle, estradiol will enhance Wnt/β-catenin signaling in the proliferative phase, while progesterone inhibits Wnt/β-catenin signaling, thus restraining estrogens' proliferative actions, during the secretory phase. In case of enhanced or unopposed estrogen signaling, constitutive activation of Wnt/β-catenin signaling will trigger endometrial hyperplasia, which may develop further into endometrial cancer