A procedure for the determination of proteolytic activity

The difficulties introduced by the desire to maintain a constant pH during an enzyme-catalyzed hydrolysis of peptide-like substrates and at the same time to determine the extent of hydrolysis by an acid-base titration have been pointed out (1), but to date no completely satisfactory solution of the problem has been given. With those enzymes whose pH optima lie in the region between pH 7.5 to 8.5, e.g. trypsin and chymotrypsin, the poor buffering capacity of phosphate in this region prompted us, as it has others (2-5), to consider the use of organic amines whose pK’alpha values were near to or identical with the pH optimum of the enzyme being used. In the course of such studies it soon became evident that coincidental use of a suitable primary or secondary amine buffer system and a formol titration (1) would insure adequate buffering capacity with low buffer concentration during the hydrolysis and at the same time permit the final acid-base titration to be conducted under nearly ideal conditions. In this communication we shall limit the discussion to results obtained with chymotrypsin and specific acylated-a-amino acid amide substrates, since the application of the general method to other proteolytic enzymes and other types of substrates will be obvious

MAD Version 9

The program MAD is widely used for accelerator design and beam dynamics studies. For many years, its input language has been the nearest thing to a world-wide standard for describing accelerator structures. The new Version 9 is a complete rewrite using a systematic object-oriented methodology based on the CLASSIC classes [2] for accelerator physics. It provides many improvements over the previous MAD Version 8. These include: (i) support for multiple beam-lines simultaneously, facilitating, for example, matching constraints that couple the two rings of a two-ring collider, (ii) much improved Lie-algebraic map calculations, (iii) a uniform method and format for exchanging many kinds of structured data with other programs, (iv) an improved and more consistent input language. In addition, we report on a parallel 3D Poisson field solver for space charge calculations in high intensity particle beams. Applied to the PSI injector cyclotron, this shows the general nature of MAD Version 9 as a state-of- the-art problem-solving environment. We describe the current status of the program and how to get it, outline future plans and illustrate some of the new features

Beam Dynamics in High Intensity Cyclotrons Including Neighboring Bunch Effects: Model, Implementation and Application

Space charge effects, being one of the most significant collective effects, play an important role in high intensity cyclotrons. However, for cyclotrons with small turn separation, other existing effects are of equal importance. Interactions of radially neighboring bunches are also present, but their combined effects has not yet been investigated in any great detail. In this paper, a new particle in cell based self-consistent numerical simulation model is presented for the first time. The model covers neighboring bunch effects and is implemented in the three-dimensional object-oriented parallel code OPAL-cycl, a flavor of the OPAL framework. We discuss this model together with its implementation and validation. Simulation results are presented from the PSI 590 MeV Ring Cyclotron in the context of the ongoing high intensity upgrade program, which aims to provide a beam power of 1.8 MW (CW) at the target destination

A Comparison of Two Shallow Water Models with Non-Conforming Adaptive Grids: classical tests

In an effort to study the applicability of adaptive mesh refinement (AMR) techniques to atmospheric models an interpolation-based spectral element shallow water model on a cubed-sphere grid is compared to a block-structured finite volume method in latitude-longitude geometry. Both models utilize a non-conforming adaptation approach which doubles the resolution at fine-coarse mesh interfaces. The underlying AMR libraries are quad-tree based and ensure that neighboring regions can only differ by one refinement level. The models are compared via selected test cases from a standard test suite for the shallow water equations. They include the advection of a cosine bell, a steady-state geostrophic flow, a flow over an idealized mountain and a Rossby-Haurwitz wave. Both static and dynamics adaptations are evaluated which reveal the strengths and weaknesses of the AMR techniques. Overall, the AMR simulations show that both models successfully place static and dynamic adaptations in local regions without requiring a fine grid in the global domain. The adaptive grids reliably track features of interests without visible distortions or noise at mesh interfaces. Simple threshold adaptation criteria for the geopotential height and the relative vorticity are assessed.Comment: 25 pages, 11 figures, preprin

Post-traumatic stress disorder in parturients delivering by caesarean section and the implication of anaesthesia: a prospective cohort study.

Post-traumatic stress disorder (PTSD) occurs in 1-7% of women following childbirth. While having a caesarean section (C-section) is known to be a significant risk factor for postpartum PTSD, it is currently unknown whether coexisting anaesthesia-related factors are also associated to the disorder. The aim of this study was to assess anaesthesia-linked factors in the development of acute postpartum PTSD. We performed a prospective cohort study on women having a C-section in a tertiary hospital in Switzerland. Patients were followed up six weeks postpartum. Patient and procedure characteristics, past morbidity or traumatic events, psychosocial status and stressful perinatal events were measured. Outcome was divided into two categories: full PTSD disease and PTSD profile. This was based on the number of DSM-IV criteria of the Diagnostic and Statistical Manual of Mental Disorders 4th edition (DSM-IV) present. The PTSD Checklist Scale and the Clinician Administered PTSD Scale were used for measurement. Of the 280 patients included, 217 (77.5%) answered the questionnaires and 175 (62.5%) answered to an additional phone interview. Twenty (9.2%) had a PTSD profile and six (2.7%) a PTSD. When a full predictive model of risk factors for PTSD profile was built using logistic regression, maternal prepartum and intrapartum complications, anaesthetic complications and dissociative experiences during C-section were found to be the significant predictors for PTSD profile. This is the first study to show in parturients having a C-section that an anaesthesia complication is an independent risk factor for postpartum PTSD and PTSD profile development, in addition to known perinatal and maternal risk factors

Enhancement of tissue lesion depth by dual wavelength irradiation with the Nd-YAG/KTP laser: Perspectives for laser prostatectomy

The Nd-YAG/KTP laser coagulates and vaporizes prostate tissue. The objective of this study was to investigate the combined effects of both wavelengths and to determine the irradiation parameters allowing the largest lesion volume. Chicken breast tissue was irradiated ex vivo. Consecutive 1064 and 532 nm Nd-YAG/KTP laser irradiations were performed for different combinations (30 W/10 W, 20 W/20 W, 10 W/30 W) with variable total fluence (1200 J, 2400 J, 3600 J) and compared to isofluent single wavelengths at 40 W irradiation. The depths, diameters and volumes of the total lesion as well as the vaporization effects of the 532 nm wavelength on normal and on priorly coagulated tissue were analysed. Maximum total lesion depths (p< 0.001) were found under combined Nd-YAG/KTP (20 W/20 W) irradiation conditions. Ablation efficacy of the 532 nm wavelength was reduced after prior 1064 nm irradiation, but crater depths were increased. Dual wavelength irradiation with the Nd-YAG/KTP laser induces a specific denaturation process. This may represent a new approach to increase the depth of coagulation necrosis, and thus the treated volume, thereby improving long-term result

Pleasure as Pedagogy: Rethinking Risk-Based Narratives in Contemporary Sex Education

Contemporary sex education in the United States overwhelmingly emphasizes risk prevention, focusing on sexually transmitted infections (STIs), pregnancy, and sexual assault, largely omitting discussions of sexual pleasure. Recognizing this gap, this thesis explores how pleasure can function as a central pedagogical tool in sex education. Grounded in framing theory, social constructionism, theories of biopower, and a sociological theory of pleasure, this thesis examines how dominant risk-based narratives impact the efficacy of sex education. Using qualitative methodology, I conducted semi-structured interviews with students from the Claremont Colleges to investigate how their early sex education experiences shaped their later understandings of sex and sexuality. Findings reveal that participants overwhelmingly recalled their sex education as negative, fear-based, and lacking instruction on pleasure, negatively impacting their relationships to their own sexualities. The results suggest that reframing sex education to center pleasure, rather than risk, holds transformative potential. I argue a paradigm shift in sex education policy and practice away from risk, towards pleasure. I suggest that reframing sex education around pleasure will challenge entrenched cultural narratives about sex and offer a pathway toward a more sexually literate and healthy society

Does implicit memory during anaesthesia persist in children?

Background Recent studies suggest that implicit memory (especially perceptual implicit memory) persists during adequate general anaesthesia in adults. Studies in children, however, have failed to demonstrate implicit memory during general anaesthesia, possibly because of differences in methodological design. We therefore designed a prospective study with the aim of evaluating implicit memory in children undergoing general anaesthesia, using a perceptual memory test based on the mere exposure effect, previously tested in a control group. Methods Twelve infrequent neutral words were played 12 times in a random sequence via headphones to 36 children aged 8-12 yr during elective or emergency surgery. The children were not premedicated, and general anaesthesia was maintained with isoflurane. The word presentation started immediately after the surgical incision. Within 36 h after the stimulus presentation, the memory was assessed by using a forced-choice preference judgement task. Time constraint and word deterioration with a low-pass filter were used to prevent the subjects from utilizing intentional retrieval. The implicit memory score was obtained by calculating the proportion of target words preferred, which was compared with the chance level (0.5). Results The percentage of correct responses given by the children was comparable with the chance level. The memory score was mean (sd) 0.48 (0.16) (95% CI 0.43-0.53). Conclusions The use of a perceptual implicit memory test based on the mere exposure procedure in children failed to reveal any evidence of implicit memory under general anaesthesi