Development of the preterm infant gut microbiome: a research priority.

The very low birth weight (VLBW) infant is at great risk for marked dysbiosis of the gut microbiome due to multiple factors, including physiological immaturity and prenatal/postnatal influences that disrupt the development of a normal gut flora. However, little is known about the developmental succession of the microbiota in preterm infants as they grow and mature. This review provides a synthesis of our understanding of the normal development of the infant gut microbiome and contrasts this with dysbiotic development in the VLBW infant. The role of human milk in normal gut microbial development is emphasized, along with the role of the gut microbiome in immune development and gastroenteric health. Current research provides evidence that the gut microbiome interacts extensively with many physiological systems and metabolic processes in the developing infant. However, to the best of our knowledge, there are currently no studies prospectively mapping the gut microbiome of VLBW infants through early childhood. This knowledge gap must be filled to inform a healthcare system that can provide for the growth, health, and development of VLBW infants. The paper concludes with speculation about how the VLBW infants' gut microbiome might function through host-microbe interactions to contribute to the sequelae of preterm birth, including its influence on growth, development, and general health of the infant host

Eigenvalue initialisation and regularisation for Koopman autoencoders

Regularising the parameter matrices of neural networks is ubiquitous in training deep models. Typical regularisation approaches suggest initialising weights using small random values, and to penalise weights to promote sparsity. However, these widely used techniques may be less effective in certain scenarios. Here, we study the Koopman autoencoder model which includes an encoder, a Koopman operator layer, and a decoder. These models have been designed and dedicated to tackle physics-related problems with interpretable dynamics and an ability to incorporate physics-related constraints. However, the majority of existing work employs standard regularisation practices. In our work, we take a step toward augmenting Koopman autoencoders with initialisation and penalty schemes tailored for physics-related settings. Specifically, we propose the "eigeninit" initialisation scheme that samples initial Koopman operators from specific eigenvalue distributions. In addition, we suggest the "eigenloss" penalty scheme that penalises the eigenvalues of the Koopman operator during training. We demonstrate the utility of these schemes on two synthetic data sets: a driven pendulum and flow past a cylinder; and two real-world problems: ocean surface temperatures and cyclone wind fields. We find on these datasets that eigenloss and eigeninit improves the convergence rate by up to a factor of 5, and that they reduce the cumulative long-term prediction error by up to a factor of 3. Such a finding points to the utility of incorporating similar schemes as an inductive bias in other physics-related deep learning approaches.Comment: 18 page

The Difficulty of Making Reparations Affects the Intensity of Collective Guilt

We examined how the difficulty of making reparations for the harm done to another group affects the intensity of collective guilt. Men were confronted with information documenting male privilege and were told that they would have a chance to help women and reduce patriarchy by collecting signatures on a petition. We manipulated the difficulty of making reparations by asking participants to collect 5, 50, or 100 signatures. As predicted by Brehm's (1999) theory of emotional intensity, collective guilt was a non-monotonic function of the difficulty of making reparations. Men in the moderate difficulty (50 signatures) condition expressed greater collective guilt than participants in the low (5) or high (100) difficulty conditions. Results are discussed in terms of the implications for the theory of emotional intensity, collective guilt, and collective emotions more generally

Relationship between urinary calcium and calcium intake during calcitriol administration

Relationship between urinary calcium and calcium intake during calcitriol administration. The hypercalciuria that occurs when 1,25(OH)2D3 (calcitriol) is given to humans with normal renal function depends on dietary Ca absorption and may also relate, in part, to enhanced bone resorption. To evaluate the relationship between urinary and dietary Ca during treatment with calcitriol, 12 metabolic balance studies were performed in normal volunteers ingesting a diet containing 350 mg/day of Ca, to which Ca gluconate was added. After 10 days on either 350 mg/day or 1550 mg/day of Ca, calcitriol, 0.5 µg every 12hr, was given. Then diet Ca was changed in successive 5-day treatment periods from 350 to 650, 950 and 1550 mg/day (group A) or from 1550 to 950, 650 and 350 mg/day (group B). On the lowest diet Ca, urinary Ca was less than Ca intake during calcitriol treatment (group A, 220 ± 50 mg/day; group B, 247 ± 40). As diet Ca was changed during calcitriol treatment, urinary Ca correlated with diet Ca (r = 0.60) until diet Ca reached 950 mg/day. With calcitriol, serum iPTH fell by 18 to 25% (P < 0.01) and urinary hydroxyproline fell by 11 to 19% (P < 0.05 to 0.01). Baseline serum levels of 1,25(OH)2D were 47 ± 8 and 34 ± 5 pg/ml in group A and B, respectively, and the values increased to 51 ± 12 and 45 ±7.4 pg/ml during treatment with calcitriol. Serum Ca from fasted subjects was not affected by calcitriol, but the mean postabsorptive serum Ca (noon) was increased by 0.35 mg/dl. Although urine Ca/creatinine from fasted subjects increased with calcitriol treatment, the values varied directly with the 24-hr urine Ca and inversely with serum iPTH levels. Thus, dietary Ca is the major determinant of urinary Ca during treatment with calcitriol, and the latter may decrease dietary Ca requirements. There was no evidence for an increased bone resorption. The reduction of hydroxyproline excretion suggests that bone resorption was initially depressed, perhaps due to iPTH suppression. The data also suggest that urine Ca/creatinine after fasting for 12 hr is influenced by previous dietary Ca intake or intestinal Ca absorption, perhaps related to changing iPTH levels

Prospective evaluation of prognostic factors in operable breast cancer.

In 215 patients with operable breast cancer (T1-T3, N0-1, M0) and no other or previous cancer, presenting to a single breast unit, sufficient tumour was available for the prospective determination of four putative biochemical markers of prognosis: oestrogen receptor (ER) activity, cathepsin D (cath D), epidermal growth factor receptor (EGFR) activity and cyclic AMP-binding proteins (c-AMP-b). There were significant inter-relationships between ER and EGFR (r = -0.26), c-AMP-b and cath D (r = +0.32) and ER and c-AMP-b (r = +0.14). After follow-up (median 36.2 months), a total of 55 recurrences (18 locoregional only) and 35 deaths were recorded. By univariate analysis, up to 10 of 18 biochemical, clinical and histopathological variables of potential prognostic value were significantly related to disease-free interval or death, but by multivariate analysis only oestrogen receptor concentration and node status contributed significantly to risk of both distant recurrence/death; in addition, tumour size made a small contribution to the risk for a distant recurrence only. Only two parameters, tumour grade and ER concentration, were significantly related to risk of locoregional recurrence by univariate analysis, but by multivariate analysis, only tumour grade was important. It is concluded that tumour ER concentration, axillary nodal status and tumour grade remain as the most important prognostic factors in the early years after presentation of operable breast cancer, with a minor influence of tumour size. At this time, the prognostic significance of quantitative measurements of ER concentration, carefully controlled for the quality of both assay and tumour specimen, is probably greater than is generally appreciated. We have yet to identify other factors, which add significantly to the short-term prognostic value of these key features

Review of Nuclear Physics Experiments for Space Radiation

Human space flight requires protecting astronauts from the harmful effects of space radiation. The availability of measured nuclear cross section data needed for these studies is reviewed in the present paper. The energy range of interest for radiation protection is approximately 100 MeV/n to 10 GeV/n. The majority of data are for projectile fragmentation partial and total cross sections, including both charge changing and isotopic cross sections. The cross section data are organized into categories which include charge changing, elemental, isotopic for total, single and double differential with respect to momentum, energy and angle. Gaps in the data relevant to space radiation protection are discussed and recommendations for future experiments are made