Multilayer analysis of anisotropic heat flux in verticalcavity-surface emitting lasers with quarter-wave semiconducting mirrors

Monolithic arrays of vertical cavity-surface emitting lasers (VCSELs) have the potential to be used in microwave systems based on opto-electronic technologies. However, the temperature has a strong influence over several characteristics of VCSELs. Self-heating may restrain the gain inside the device cavity and it is responsible for an increase in the laser threshold current as well as a decrease of its output power. In this paper, the thermal behavior of VCSELs was evaluated by means of a procedure that takes into account the multilayer aspects of the heat-flux propagation. The method has the advantage of dealing with the heat propagation inside each layer of the periodic structures of the device. Thus, the different characteristics and influence of the materials employed in the chip manufacturing can he considered and the device temperature profile can be predicted. From the method assumptions and simulations, the thermal resistances of typical devices were calculated. The results were shown to be in good agreement with experimental values reported in the literature     

Free me from this nail! Please!

Ingrowing toenails are a very frequent pathology in children and adolescents. There is an anatomic component, but also other factors, such as inadequate shoes and incorrect nail-trimming. We treated 47 patients with 69 ingrowing toenails, between one and 15 years of age. The evolution time was one month to 10 years and 11 patients had precedent surgeries. Lateral electrosurgical matricectomy was the choice technique. With a follow up of at least eight months, there is only one case of recurrence.     

ADSA Foundation Scholar Award: New frontiers in calf and heifer nutrition—From conception to puberty

Dairy calf nutrition is traditionally one of the most overlooked aspects of dairy management, despite its large effect on the efficiency and profitability of dairy operations. Unfortunately, among all animals on the dairy farm, calves suffer from the highest rates of morbidity and mortality. These challenges have catalyzed calf nutrition research over the past decade to mitigate high incidences of disease and death, and improve animal health, growth, welfare, and industry sustainability. However, major knowledge gaps remain in several crucial stages of development. The purpose of this review is to summarize the key concepts of nutritional physiology and programming from conception to puberty and their subsequent effects on development of the calf, and ultimately, future performance. During fetal development, developmental plasticity is highest. At this time, maternal energy and protein consumption can influence fetal development, likely playing a critical role in calf and heifer development and, importantly, future production. After birth, the calf's first meal of colostrum is crucial for the transfer of immunoglobulin to support calf health and survival. However, colostrum also contains numerous bioactive proteins, lipids, and carbohydrates that may play key roles in calf growth and health. Extending the delivery of these bioactive compounds to the calf through a gradual transition from colostrum to milk (i.e., extended colostrum or transition milk feeding) may confer benefits in the first days and weeks of life to prepare the calf for the preweaning period. Similarly, optimal nutrition during the preweaning period is vital. Preweaning calves are highly susceptible to health challenges, and improved calf growth and health can positively influence future milk production. Throughout the world, the majority of dairy calves rely on milk replacer to supply adequate nutrition. Recent research has started to re-evaluate traditional formulations of milk replacers, which can differ significantly in composition compared with whole milk. Transitioning from a milk-based diet to solid feed is critical in the development of mature ruminants. Delaying weaning age and providing long and gradual step-down protocols have become common to avoid production and health challenges. Yet, determining how to appropriately balance the amount of energy and protein supplied in both liquid and solid feeds based on preweaning milk allowances, and further acknowledging their interactions, shows great promise in improving growth and health during weaning. After weaning and during the onset of puberty, heifers are traditionally offered high-forage diets. However, recent work suggests that an early switch to a high-forage diet will depress intake and development during the time when solid feed efficiency is greatest. It has become increasingly clear that there are great opportunities to advance our knowledge of calf nutrition; yet, a more concentrated and rigorous approach to research that encompasses the long-term consequences of nutritional regimens at each stage of life is required to ensure the sustainability and efficiency of the global dairy industry.     

Effect of energy source in calf milk replacer on performance,digestibility, and gut permeability in rearing calves

Current calf milk replacer (CMR) compositions significantly differ from whole milk in their levels of energy, protein, and minerals. Energy source is one of the major differences, as CMR contains high levels of lactose, whereas whole milk contains higher levels of fat. The aim of this study was to determine the effect of partially exchanging lactose for fat on performance, digestibility, and gut permeability in calves fed twice daily on a high feeding plane. Lactose and fat were exchanged in the CMR formulation on a weight–weight basis. The CMR were isonitrogenous but not isoenergetic. A total of 60 male Holstein-Friesian calves were assigned to 1 of 30 blocks based on serum IgG, body weight, and date of collection after birth. Within each block, calves were randomly assigned to 1 of 2 treatments: high fat and high lactose. The CMR was provided twice daily until 49 d of age, followed by a gradual weaning period of 14 d. Starter, straw, and water were available ad libitum throughout the complete study. Exchanging lactose for fat did not affect growth; intakes of starter, straw, water, crude protein, or total energy; or apparent total-tract digestibility of nutrients. Gastrointestinal permeability was assessed by measuring the recovery of lactulose and Cr in 24-h urine and the Cr concentration and lactulose:d-mannitol ratio in serum following an oral pulse dose. Urinary recoveries of Cr and lactulose were generally low in both treatments but were higher in calves fed the high-fat CMR. Accordingly, the serum lactulose:d-mannitol ratio and serum Cr concentrations were higher in calves fed the high-fat CMR. In wk 1 and during the weaning transition, calves fed the high-fat CMR had significantly fewer abnormal fecal scores. In conclusion, exchanging lactose for fat in the CMR did not affect growth performance, total feed intake, or nutrient digestibility. The high-fat CMR was associated with an increase in permeability markers but positively influenced fecal scores in calves.     

Energy sustainability indicators for local energy planning: Review of current practices and derivation of a new framework

Tackling climate change is a growing concern of our society. Although action is needed at all levels of governance, local authorities play a key role in climate action. The creation of sustainable energy and climate action plans at the local level are recent trends that show increasing local commitment. During the last decade, several municipalities have started to develop plans, but surprisingly little systematic technical guidance has been provided to them. As part of an effort to develop tools to assist energy planning at the local level, this study addresses the role of indicators in energy planning. This paper aims to propose a framework of local energy sustainability indicators to be used both as an assessment and as an action-planning tool. A literature review of existing sets of sustainability indicators and the testing of the selected indicators with pilot municipalities has led to a framework composed by 18 indicators. The indicators proposed were developed by having into consideration, besides relevance, their potential use as decision criteria for identifying the most effective actions for local energy planning. The paper also investigates the presence of the proposed indicators in existing local sustainability assessment initiatives and energy and climate action plans as well as the purpose for which they were being used in the plans. The analysis of 10 local energy and climate action plans has revealed that local authorities are using indicators mostly for diagnosis purposes, paying less attention to monitoring. Using indicators as decision criteria to choose the actions to be included in the action plan is not yet a common practice. It was also found that only a small number of the indicators proposed in this paper were already considered in the action plans analysed.     

GODDESS: A Goal-Directed Decision Structuring System

This paper describes an operational version of a computerized, domain-independent, decision support system which is based on a novel, goal-directed structure for representing decision problems. The structure allows the user to state relations among aspects, effects, conditions, and goals, in addition to actions and states which are the basic components of the traditional decision tree approach. The program interacts with the user in a stylized English-like dialogue, starting with the stated objectives and proceeding to unravel the more detailed means by which these objectives can be realized. At any point in time, the program focuses the user's attention on the issues which are most crucial to the problem at hand. The structure used is more compatible with the way people encode knowledge about problems and actions, and therefore promises to offer the following advantages: 1) judgments and beliefs issued by the user constitute a more valid representation of the user's experience; and 2) the user may be guided toward the discovery of action alternatives he otherwise would not have identified.     

Textile industry and environment: can the use of bacterial cellulose in the manufacture of biotextiles contribute to the sector?

Clean Technologies and Environmental Policy - The textile industry is one of the most complex sectors in relation to environmental degradation, both with regard to the materials used from petroleum...     

Design optimization of multilayer perceptron neural network by ant colony optimization applied to engine emissions data

Science China Technological Sciences - A multilayer perceptron (MLP) artificial neural network (ANN) model has been optimized by the multi-objective ant colony optimization (MOACO) algorithm, which...     

Connective Tissue Reaction of Rats to a New Zinc‐Oxide‐Eugenol Endodontic Sealer

The aim of this study was to evaluate the biocompatibility in rat subcutaneous connective tissue of a new zinc oxide endodontic sealer (Endomethasone N) compared to those provided by Endofill and Sealer 26. Polyethylene tubes containing the test materials were implanted into dorsal subcutaneous connective tissue of Wistar albino rats. After 7 and 42 days, the implants with the surrounding tissue were collected, fixed, and processed for histologic evaluation. Sections were evaluated for the presence of inflammatory cells (poly or monomorfonuclear), blood vessels, necrosis area, and thickness of fibrous capsule. Comparisons between groups and time‐periods were performed with Kruskal–Wallis and Mann–Whitney U non‐parametric tests for 5% significance level. No differences in the biocompatibility patterns among the materials for the 2 experimental periods were observed. Independently of the sealer, the tissue behavior showed a tendency to decrease the irritation effect over time. It can be concluded that all sealers are irritant, but its toxicity decreased with time. Endomethásone N showed biocompatible characteristics comparable with those provided by Endofill and Sealer 26. Microsc. Res. Tech. 76:1292–1296, 2013. © 2013 Wiley Periodicals, Inc.