The impact of eating behavior on psychological symptoms typical of reactive hypoglycemia. A pilot study comparing women with polycystic ovary syndrome to controls

The idea that diet can affect mood and behavior in women with polycystic ovary syndrome (PCOS) by altering blood glucose levels has become popular in recent years. This paper describes an online survey (N=462) of 24 women with PCOS, 299 healthy control women, 47 women who possibly had undiagnosed PCOS, and 92 men. The groups were compared for symptoms of mood and behavioral symptoms typical of reactive (postprandial) hypoglycemia. The outcome measures were two questionnaires that measure states associated with hypoglycemia: the Hypoglycemia Symptom Checklist-7 (HSC-7), which measures behavioral symptoms and the Mood Adjective Checklist (MACL), which measures emotional states. Controlling for age and body mass index (BMI) using between-groups analysis of covariance (ANCOVA), the women with PCOS scored significantly higher than the other three groups (p<0.001) on the outcome measures. These differences remained statistically significant in a subset of twelve women with PCOS compared to twelve healthy control women closely matched for age, BMI, and eating behavior. The findings are suggestive of hypoglycemia-related mood and behavioral problems in PCOS. Future research should test whether blood glucose levels correlate with these symptoms in PCOS, and whether a low glycemic index ('low-GI') diet improves the symptoms

Design of a Distributed Ground Support System for Small Satellites

On February 23, 1999 South Africa\u27s first satellite SUNSAT was launched. The satellite was designed and built entirely at the University of Stellenbosch, a project spanning 8 years. Up to 1999 the bulk of the development work was done on the satellite itself, with time constraints limiting the work done on the ground support system. This led to a situation where the ground station was developed in the two months prior to the launch and shortly afterwards. The system was developed with the specific purpose of supporting only SUNSAT. The final product was a ground support system consisting of a single OSCAR class ground station located at the University of Stellenbosch. The system was very effective in supporting SUNSAT, but the implementation made expansion and reuse of the system very difficult. The station requires a high degree of human operation and automating the system would require big changes in the software used. This article looks at the design of a new generation of ground support system, for use at the University of Stellenbosch\u27s satellite program on future missions. Distributed architectures are used to enable components of the system to be physically located where resources are best utilised. The design also allows for increasing levels of automation to be introduced

100 years of metal coordination chemistry: from Alfred Werner to anticancer metallodrugs

YesAlfred Werner was awarded the Nobel Prize in Chemistry just over 100 years ago. We recall briefly the era in which he was working, his co-workers, and the equipment he used in his laboratories. His ideas were ground breaking: not only does a metal ion have a primary valency (“hauptvalenz”, now the oxidation state), but also a secondary valency, the coordination number (“nebenvalenz”). At that time some refused to accept this idea, but he realised that his new thinking would open up new areas of research. Indeed it did. We illustrate this for the emerging field of medicinal metal coordination chemistry, the design of metal-based therapeutic and diagnostic agents. The biological activity of metal complexes depends intimately not only on the metal and its oxidation state, but also on the type and number of coordinated ligands, and the coordination geometry. This provides a rich platform in pharmacological space for structural and electronic diversity. It is necessary to control both the thermodynamics (strengths of metal-ligand bonds) and kinetics of ligand substitution reactions to provide complexes with defined mechanisms of action. Outer-sphere interactions can also play a major role in target recognition. Our current interest is focussed especially on relatively inert metal complexes which were very familiar to Werner (RuII, OsII, RhIII, IrIII, PtII, PtIV).We thank the Leverhulme Trust (Early Career Fellowship No. ECF-2013-414 to NPEB), the University of Warwick (Grant No. RDF 2013-14 to NPEB) the ERC (Grant No. 247450 to PJS), EPSRC (Grant No. EP/F034210/1) and EC COST Action CM1105 for support

Simulation of a high-speed demultiplexer based on two-photon absorption in semiconductor devices

In this paper, we present a theoretical model of an all-optical demultiplexer based on two-photon absorption in a specially designed semiconductor micro-cavity for use in an optical time division multiplexed system. We show that it is possible to achieve error-free demultiplexing of a 250 Gbit/s OTDM signal (25 × 10 Gbit/s channels) using a control-to-signal peak pulse power ratios of around 30:1 with a device bandwidth of approximately 30 GHz

Dispersion monitoring for high-speed WDM networks via two-photon absorption in a semiconductor microcavity

Due to the continued demand for bandwidth, network operators have to increase the data rates at which individual wavelengths operate at. As these data rates will exceed 100 Gbit/s in the next 5-10 years, it will be crucial to be able to monitor and compensate for the amount of chromatic dispersion encountered by individual wavelength channels. This paper will focus on the use of the novel nonlinear optical-to-electrical conversion process of two-photon absorption (TPA) for dispersion monitoring. By incorporating a specially designed semiconductor microcavity, the TPA response becomes wavelength dependent, thus allowing simultaneous channel selection and monitoring without the need for external wavelength filterin

A sharp growth condition for a fast escaping spider's web

We show that the fast escaping set $A(f)$ of a transcendental entire function $f$ has a structure known as a spider's web whenever the maximum modulus of $f$ grows below a certain rate. We give examples of entire functions for which the fast escaping set is not a spider's web which show that this growth rate is best possible. By our earlier results, these are the first examples for which the escaping set has a spider's web structure but the fast escaping set does not. These results give new insight into a conjecture of Baker and a conjecture of Eremenko

Halide Control of N,N-Coordination versus N,C-Cyclometalation and Stereospecific Phenyl Ring Deuteration of Osmium(II) p-Cymene Phenylazobenzothiazole Complexes

YesWe report the synthesis of halido Os(II) p-cymene complexes bearing bidentate chelating phenylazobenzothiazole (AZBTZ) ligands. Unlike the analogous phenylazopyridine (AZPY) complexes, AZBTZ-NMe2 is capable of both N,N-coordination to Os(II) and cyclometalation to form N,C-coordinated species. N,C-Coordination occurs via an azo nitrogen and an ortho carbon on the aniline ring, as identified by 1H NMR and X-ray crystallography of [Os(p-cym)(N,N-AZBTZ-NMe2)Cl]PF6 (1a), [Os(p-cym)(N,N-AZBTZ-NMe2)Br]PF6 (2a), [Os(p-cym)(N,C-AZBTZ-NMe2)Br] (2b), and [Os(p-cym)(N,C-AZBTZ-NMe2)I] (3b). The N,C-coordinated species is more stable and is not readily converted to the N,N-coordinated complex. Analysis of the crystal structures suggests that their formation is influenced by steric interactions between the p-cym and AZBTZ-NMe2 ligands: in particular, larger monodentate halide ligands favor N,C-coordination. The complexes [Os(p-cym)(N,N-Me2-AZBTZ-NH2)Cl]PF6 (4) and [Os(p-cym)(N,N-Me2-AZBTZ-NH2)I]PF6 (5) were synthesized with methyl groups blocking the ortho positions on the aniline ring, forcing an N,N-coordination geometry. 1H NMR NOE experiments confirmed hindered rotation of the arene ligand and steric crowding around the metal center. Complex 2b exhibited unexpected behavior under acidic conditions, involving regiospecific deuteration of the aniline ring at the meta position, as observed by 1H NMR and high-resolution ESI-MS. Deuterium exchange occurs only under acidic conditions, suggesting an associative mechanism. The calculated partial charges on 2b show that the meta carbon is significantly more negatively charged, which may account for the regiospecificity of deuterium exchange.ERC, EPSRC, The Royal Societ

Profiles of the forms and functions of self-reported aggression in three adolescent samples

In the current study, we addressed several issues related to the forms (physical and relational) and functions (reactive and proactive) of aggression in community (n = 307), voluntary residential (n = 1,917) and involuntarily detained (n = 659) adolescents (ages 11 to 19 years). Across samples, boys self-reported more physical aggression and girls reported more relational aggression, with the exception of higher levels of both forms of aggression in detained girls. Further, few boys showed high rates of relational aggression without also showing high rates of physical aggression. In contrast, it was not uncommon for girls to show high rates of relational aggression alone and these girls tended to also have high levels of problem behavior (e.g., delinquency) and mental health problems (e.g., emotional dysregulation, callous-unemotional traits). Finally, for physical aggression in both boys and girls, and for relational aggression in girls, there was a clear pattern of aggressive behavior that emerged from cluster analyses across samples. Two aggression clusters emerged with one group showing moderately high reactive aggression and a second group showing both high reactive and high proactive aggression (combined group). On measures of severity (e.g., self-reported delinquency and arrests) and etiologically important variables (e.g., emotional regulation and callous-unemotional traits), the reactive aggression group was more severe than a non-aggressive cluster but less severe than the combined aggressive cluster

All-optical sampling utilising two-photon absorption in semiconductor microcavity

A highly-efficient optical sampling system based on Two-Photon Absorption in a semiconductor micro-cavity is presented. The sensitivity of the sampling system is calculated to be 0.1mW² with a temporal resolution of 2ps