Chemical underpinning of the tea bag index: An examination of the decomposition of tea leaves

Decomposition is a key flux of terrestrial carbon to the atmosphere. Therefore, gaining a better understanding of how plant litter decomposes in soil, and what governs this process, is vital for global climate models. The Tea Bag Index (TBI) was introduced by Keuskamp et al. (2013) as a novel method for measuring litter decomposition rate and stabilisation. The TBI uses two types of tea bags representing fast (green tea) and slow (rooibos tea) decomposition substrates as standardised litter bags. To date, the TBI method has been used in over 2000 locations across the globe. However, before now, there has been no information on how the composition of the tea leaves change during incubation. These data are crucial in determining the validity of the use of the TBI method globally, to ensure the tea leaves decompose in a way that is representative of so-called “native” litters. To provide chemical underpinning of the TBI method, a laboratory incubation of the tea bags was conducted with destructive sampling at 0, 7, 14, 21, 28, 35, 42, 49, 56, 63, 70, 77, 84, and 91 d. The incubated tea was analysed for total C and N. In addition, C was characterised as alkyl, O-alkyl, aromatic, or carbonyl C using solid-state 13C nuclear magnetic resonance spectroscopy with cross-polarization and magic angle spinning (CPMAS NMR). The results suggest that changes in carbon in both tea types are comparable to other litter studies, with a net decrease in total C and relative proportion of O-alkyl C fraction, which contains carbohydrates and cellulose. We conclude that the decomposition of tea leaves in the bags used in the TBI is representative of other litters

Cardio-Protection Afforded by Β-Blockade Is Maintained During Resistance Exercise

Objectives Whether or not the cardio-protective effect of β-adrenergic blockade is retained during resistance exercise has not been systematically evaluated. Therefore the purpose of this study was to measure selected cardiorespiratory responses to isometric exercise involving hand-gripping, single-leg extension, or double-leg dead-lift, under placebo (control), β1-selective (atenolol), and non-selective (propranolol) adrenergic blockade conditions. Design Eleven young male adults were evaluated in a randomized, double-blinded, repeated measures study design and performed all three exercise modalities at 30% of maximal voluntary contraction under placebo, atenolol and propranolol conditions. Methods Heart rate, systolic and diastolic blood pressure, rate-pressure product, oxygen uptake, cardiac output, stroke volume and total peripheral resistance were directly measured or calculated at rest and during the third minute of each of the three exercise modes. Results Irrespective of drug condition, a graded pressor response was observed going from rest to exercise so that rest \u3c handgrip \u3c leg extension \u3c dead-lift for heart rate, systolic and diastolic blood pressures, rate-pressure product and oxygen uptake (p \u3c 0.05 for all). Cardiac output only increased with the dead-lift mode of exercise (p \u3c 0.01). Importantly β-adrenergic blockade with either atenolol or propranolol similarly attenuated the rise in heart rate, and systolic blood pressure; thus rate-pressure product demonstrated a mode-of-exercise by drug interaction effect (p \u3c 0.001) with the greatest reductions seen with the dead-lift procedure. Conclusions The findings indicate that cardio-protection afforded by selective or non-selective β-blockade at rest is preserved during isometric exercise and even enhanced once heart rate increases above 100 beats min−1

Imperial fascism : ideology, practice, and transmission in the Mediterranean, 1934-1943

This study seeks to explore the nature of imperial fascism, particularly those projects carried out by Italian and French fascists and authoritarians in North Africa from 1934 to 1943. In the wake of world war and a worldwide depression, these fascists were mindful of the limitations of the territorial nation-state, and believed that imperial structures would have to be created and maintained in order to protect the sovereignty of their nations. A shared set of ideas about the past and future of the Mediterranean provided French and Italian rightists an ideological opportunity to cooperate, but geopolitical differences and national egoism ensured that each would go their own way. With the failure of the so-called “Latin union”, both the French and Italian rightists sought to convince North Africans that only the far-right could bring about modernity while protecting Islam from secularism and communist atheism. While most North Africans rejected the fascist advances, some responded positively for a variety of reasons, though generally in ways that failed to correspond to the fascist visions of a new geopolitical order. In a bid to show their respect for Islam, fascists also employed several strategies to govern North African Muslims; foremost of these were the attempts to integrate the elites into youth organizations and a greater involvement in supporting Islamic practices in ways that depoliticized religion and linked it to the state. The governing techniques, despite attenuating some critiques of colonialism, did little to stem the growing desire for independence. Furthermore, the fascist rejection of liberal norms and values was unacceptable to most North Africans who hoped to either greatly reform colonial structures or to gain self-determination. Though French and Italians failed to legitimize their imperial projects, studying their attempts highlights the various ways in which fascists adjusted their ideas and practices in order to carry out transnational and imperial politics.Histor

Accurate depth measurement of small surface-breaking cracks using an ultrasonic array post-processing technique

AbstractIn this paper, the half-skip configuration of the Total Focusing Method (TFM) is used to image and size surface-breaking cracks. The TFM is an ultrasonic array post-processing technique which is used to synthetically focus at every image point in a target region. This paper considers the case of inspecting for cracks which have initiated from the far surface of a parallel-sided sample using an array on the near surface. Typically, only direct ray paths between the array and image points are included in the TFM algorithm and therefore the image obtained for this case consists only of root and tip indications; no specular reflection from the crack faces is captured. The tip indication often has such a poor signal-to-noise ratio that reliable crack depth measurement is challenging. With the Half-Skip TFM, instead of using directly-scattered signals, the image is formed using ultrasonic ray paths corresponding to the ultrasound that has reflected off the back surface and has then undergone specular reflection from the crack face back to the array. The technique is applied to experimental and simulated array data and is shown to measure the depth of small cracks (depth <1mm) with greater reliability than methods which rely on tip diffraction

Rapid Adaptive Programming using Image Data (RAPID)

In many welding applications, programming time has been the biggest obstacle for the widespread acceptance of robots, impeding the advancement of this technology and limiting it to medium or large batch applications. In particular, for repair of worn components where the damage is irregular, reprogramming by skilled personnel is required at added cost and time. This paper outlines a novel offline programming technique which allows robot programming to be automated and completed in a few seconds. This technique is applicable to a wide range of industrial wear applications