Utilization of photon orbital angular momentum in the low-frequency radio domain

We show numerically that vector antenna arrays can generate radio beams which exhibit spin and orbital angular momentum characteristics similar to those of helical Laguerre-Gauss laser beams in paraxial optics. For low frequencies (< 1 GHz), digital techniques can be used to coherently measure the instantaneous, local field vectors and to manipulate them in software. This opens up for new types of experiments that go beyond those currently possible to perform in optics, for information-rich radio physics applications such as radio astronomy, and for novel wireless communication concepts.Comment: 4 pages, 5 figures. Changed title, identical to the paper published in PR

Solar assisted pervaporation (SAP) for preserving and utilizing fruits in developing countries

Paper presented to the 3rd Southern African Solar Energy Conference, South Africa, 11-13 May, 2015.The purpose of this work is to develop and implement a simple and robust preservation technology that can enhance food and economic security and thereby improve the lives of people in developing countries. The technique under development is termed “solar assisted pervaporation (SAP)”. It is a sustainable technology whereby fruit juices or purées are concentrated using reusable pouches made of “breathable textiles”. The active layer of the textile is permeable to water vapour but not liquid water, and the process is related to the techniques pervaporation and membrane distillation. The pouches are filled with the juice/purée, hung from a tree or placed on a roof or in a solar dryer, and then exposed to sun and air for a specified period of time. A storage stable concentrate can be produced within 10 to 45 hours (depending on the conditions) and the entire concentration process is done using only solar energy. The fruit juice concentrate can be stored in the household or sold, thereby increasing both food and economic security in local communities. To demonstrate the feasibility of this technique, three different fruits/juices were concentrated by placing prototype pouches in a convective dryer to simulate a ventilated solar collector, or by exposing the pouches to a solar lamp equipped with convective air circulation to simulate ambient drying with direct sunlight exposure. Drying curves were obtained experimentally and the concentrates were analysed in terms of moisture content, water activity and degrees Brix. Depending on the drying time and type of fruit, the resulting product can be syrup-like, pasty, or have the texture of fruit leather. Under certain drying conditions, the water removal rate is actually higher for the pouch versus an open dish of the same dimensions because the pouch has two sides for mass transfer. Horizontal drying was found to be more effective than vertical drying and dissolved solids content was found to affect drying rate. Initial tests with a solar lamp have shown that drying rate increases with increasing radiant energy flux. It was also found that composition (fiber vs. sugar content) and form (purée vs. juice) of the fruit determines its compatibility with the pouch and drying technique. The results indicate that the technique is feasible and have given insight into how the bag should be designed.dc201

CRY2 Is Associated with Depression

Abnormalities in the circadian clockwork often characterize patients with major depressive and bipolar disorders. Circadian clock genes are targets of interest in these patients. CRY2 is a circadian gene that participates in regulation of the evening oscillator. This is of interest in mood disorders where a lack of switch from evening to morning oscillators has been postulated.We observed a marked diurnal variation in human CRY2 mRNA levels from peripheral blood mononuclear cells and a significant up-regulation (P = 0.020) following one-night total sleep deprivation, a known antidepressant. In depressed bipolar patients, levels of CRY2 mRNA were decreased (P = 0.029) and a complete lack of increase was observed following sleep deprivation. To investigate a possible genetic contribution, we undertook SNP genotyping of the CRY2 gene in two independent population-based samples from Sweden (118 cases and 1011 controls) and Finland (86 cases and 1096 controls). The CRY2 gene was significantly associated with winter depression in both samples (haplotype analysis in Swedish and Finnish samples: OR = 1.8, P = 0.0059 and OR = 1.8, P = 0.00044, respectively).We propose that a CRY2 locus is associated with vulnerability for depression, and that mechanisms of action involve dysregulation of CRY2 expression

Birth weight for gestational age and later cardiovascular health: a comparison between longitudinal Finnish and indigenous Australian cohorts

Introduction: Small or large birth weight for gestational age has been linked with later cardiovascular disease risk. However, cardiovascular risk markers from childhood to adulthood according to birth weight in diverse longitudinal settings globally have not been extensively studied.Objectives: To examine the relationship between birth weight and cardiovascular risk profile from childhood until young adulthood in two geographically and socioeconomically distinct cohorts.Methods: Data were derived from two longitudinal birth cohort studies; one from southern Finland (Special Turku Coronary Risk Factor Intervention Project, STRIP) and one from northern Australia comprising Indigenous Australians (Aboriginal Birth Cohort, ABC). The sample included 747 Finnish participants and 541 Indigenous Australians with data on birth weight, gestational age and cardiovascular risk factors (body mass index [BMI]), waist-to-height ratio [WHtR], lipid profile, blood pressure) collected at ages 11, 18 and 25 or 26 years. Carotid intima-media thickness (cIMT) was assessed at age 18 or 19 years. Participants were categorised according to birth weight for gestational age (small [SGA], appropriate [AGA] or large [LGA]). Associations between birth weight category and cardiovascular risk markers were studied using a repeated measures ANOVA.Results: Higher birth weight category was associated with higher BMI later in life in both cohorts (p=.003 for STRIP and pp=.004). In the ABC, SGA participants had lower systolic and diastolic blood pressure than AGA participants (p=.028 for systolic, p=.027 for diastolic) and lower systolic blood pressure than LGA participants (p=.046) at age 25. In the STRIP cohort, SGA participants had lower cIMT than LGA participants (p=.024).Conclusions: Birth weight can predict future cardiovascular risk profile in diverse populations. Thus, it needs to be included in targeted public health interventions for tackling the obesity pandemic and improving cardiovascular health worldwide.Key messagesThe strongest association between birth weight and later cardiovascular risk profile was manifested as differences in body mass index in two culturally and geographically distinct cohorts.Foetal growth is a determinant for later cardiovascular health in diverse populations, indicating a need to focus on maternal and foetal health to improve cardiovascular health worldwide.</p

Proteomic analysis at the sites of clinical infection with invasive Streptococcus pyogenes

Invasive Streptococcus pyogenes infections are rare, with often-unexplained severity. Prompt diagnosis is desirable, as deaths can occur rapidly following onset and there is an increased, but preventable, risk to contacts. Here, proteomic analyses of clinical samples from invasive human S. pyogenes infections were undertaken to determine if novel diagnostic targets could be detected, and to augment our understanding of disease pathogenesis. Fluid samples from 17 patients with confirmed invasive S. pyogenes infection (empyema, septic arthritis, necrotising fasciitis) were analysed by proteomics for streptococcal and human proteins; 16/17 samples had detectable S. pyogenes DNA. Nineteen unique S. pyogenes proteins were identified in just 6/17 samples, and 15 of these were found in a single pleural fluid sample including streptococcal inhibitor of complement, trigger factor, and phosphoglycerate kinase. In contrast, 469 human proteins were detected in patient fluids, 177 (38%) of which could be identified as neutrophil proteins, including alpha enolase and lactotransferrin which, together, were found in all 17 samples. Our data suggest that streptococcal proteins are difficult to detect in infected fluid samples. A vast array of human proteins associated with leukocyte activity are, however, present in samples that deserve further evaluation as potential biomarkers of infection

Higher productivity in importing German manufacturing firms: self-selection, learning from importing, or both?

This paper uses a newly available comprehensive panel data set for manufacturing enterprises from 2001 to 2005 to document the first empirical results on the relationship between imports and productivity for Germany, a leading actor on the world market for goods. Furthermore, for the first time the direction of causality in this relationship is investigated systematically by testing for self-selection of more productive firms into importing, and for productivity-enhancing effects of imports ('learning-by-importing'). We find a positive link between importing and productivity. From an empirical model with fixed enterprise effects that controls for firm size, industry, and unobservable firm heterogeneity we see that the premia for trading internationally are about the same in West and East Germany. Compared to firms that do not trade at all two-way traders do have the highest premia, followed by firms that only export, while firms that only import have the smallest estimated premia. We find evidence for a positive impact of productivity on importing, pointing to self-selection of more productive enterprises into imports, but no clear evidence for the effect of importing on productivity due to learning-by-importing