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Additional file 1.

Supplementary file 1: Area under the receiver operating characteristic (AUROC) curve

On July 30, 2021, the administration of a third (booster) dose of the COVID-19 vaccine was introduced to enhance immunity among vaccinated people. Many developed countries have introduced vaccine booster doses as additional protection for their population to mitigate the severity of the ongoing COVID-19 pandemic. However, this idea is currently being replicated by low- and lower-middle-income countries (LMICs), where full vaccination coverage is, as of now, still below 45%, which is considerably lower than that of high-income countries (73%). This commentary focuses on the critiques of introducing booster dose strategy in low-income countries. We highlight different decolonizing global health perspectives, including vaccine equity, effective resource utilization, and priority setup, in this commentary.

Understanding the linkage between the nutrient composition of foods and individuals’ recommended nutrient intake is important to address malnutrition. Despite it being a traditional and popular food item in Bangladesh, the nutrient composition of dry fish has not been reviewed yet. This study used a narrative review to assess the nutrient composition of dry fish and estimated its potential contribution to addressing some common nutritional deficiencies among children and pregnant and lactating women in Bangladesh. Records were collected from different databases, including the Web of Science, Google Scholar, PubMed, ScienceDirect, Banglajol, and ResearchGate. Data were extracted from 48 articles containing 1128 entries regarding nutrient composition. Most of the nutrient analyses estimated the proximate composition, whereas vitamin, mineral, amino acid, and fatty acid compositions were scarce in the literature. We found that dry fish has high protein and mineral content and could contribute highly to meeting the recommended nutrient intake of protein, iron, zinc, and calcium for children and pregnant and lactating women. The summarized nutrient composition data could be useful for further research to observe how dry fish could be best utilized to address malnutrition in Bangladesh. This narrative review recommends that further nutrient analysis, with emphasis on vitamin, mineral, and fatty acid compositions.

This chapter will provide background information in the development of BDFs and their applications in optical communication systems. Herein, the main focus is briefly described previous studies on BDFs that have attracted much interest over the last two decades. This necessary information and concepts are very much relevant to understanding this book, mainly due to the doping of Bi in the studied bismuth and erbium-doped silicate fibers (BEDFs). The remaining chapter is consisting of the following sections: Sec.2: General introduction about optical fibers. Sec. 3 discusses the general spectral characteristics of BDFs. Sec.4: Including the active centers (namely the bismuth (Bi) active centers (BACs)) responsible for the spectral properties in Bi-doped fibers. Sec.4 Discusses the Bismuth Doped Fiber Amplifier (BDFA).

This chapter will provide background information in the development of BDFs and their applications in optical communication systems. Herein, the main focus is briefly described previous studies on BDFs that have attracted much interest over the last two decades. This necessary information and concepts are very much relevant to understanding this book, mainly due to the doping of Bi in the studied bismuth and erbium-doped silicate fibers (BEDFs). The remaining chapter is consisting of the following sections: Sec.2: General introduction about optical fibers. Sec. 3 discusses the general spectral characteristics of BDFs. Sec.4: Including the active centers (namely the bismuth (Bi) active centers (BACs)) responsible for the spectral properties in Bi-doped fibers. Sec.4 Discusses the Bismuth Doped Fiber Amplifier (BDFA).

One of our previous papers was devoted to threshold voltage in MOSFETs and MODFETs viewed as a problem of nonlinear dynamics. The behavior of surface carriers' concentration under D.C. (direct current) applied voltage has been investigated in details. In this paper we went a step further and investigated the behavior of the same quantity under combined D.C. and A.C. (alternating current). As a main result emerged that it was impossible to cause small harmonic oscillations of surface carriers' concentration around some equilibrium value regardless of applied D.C. voltage and thus imposed operating regime.

The focus of this paper was the investigation and modeling of transport characteristics in a strained SiGe based MOSFET structure, which might be of fundamental importance for the understanding of its operating characteristics. In the investigation, carrier mobility dependence on the lateral and vertical electric field is especially considered. Carrier mobility models for long channel as well as short channel SiGe MOSFETs are also presented. Average effective electric field model is proposed taking into account impact of high electric field effects on the effective channel length. In the final effective carrier mobility model, for the short channel SiGe MOSFETs, serial drain to source resistance is included. At the same time, proposed models are relatively simple. By using the presented model, simulations were performed.

A widely known (and also very well examined) problem of threshold voltage in MOSFETs and MODFETs has been described with the tools of nonlinear dynamics. Some interesting features of such devices have been derived, together with the outstanding differences between them.

In this paper the new analytical model of current - voltage characteristics of a Heterostructure Field Effect Transistor (HFET), is proposed. The model is relatively simple, and at the same time, it describes complex HFET physics. In the new model, most of the parameters have a clear, physical meaning. Presented model includes HFET carrier mobility model, as well as HFET electric field model. Temperature influence is included in the model too. This model is suitable for the design and simulation of different types of HFETs. The results derived from simulations based on the proposed model are in very good agreement with the already known experimental data and theoretically obtained results, available in literature.

In this paper modern approach to the investigation of carriers' concentration applicable to various semiconductor structures has been developed. The model has exploited transport equation with the quantum correction term included; this transport equation is a consequence of density matrix formalism and moment expansion of corresponding expressions. The achievements of this approach have been tested in the investigation of widely used semiconductor structures. The preliminary theoretical results have been compared with results available in the literature and previously formed knowledge related to this topic.

A new analytical model of electric field in heterojunction region of heterostructure field effect transistor (HFET), is presented. Electric field dependences on surface density of two-dimensional electron gas and surface density of ionized acceptors in buffer layer are included in developed model, The expression of the electric field intensity is given by using the new correction coefficient. The new coefficient emphasizes more precisely extremely asymmetric spreading of the electric field in the vicinity of a heterojunction. Proposed model is simple and it can be straightforwardly implemented. It can be applied to quite different types of HFETs. The results derived from simulations based on the exposed model are in very good agreement with the already known ones, available in literature.

In this paper a new analytical carrier mobility model of a heterostructure unipolar transistor, High Electron Mobility Transistor (HEMT), is presented. The influence of the two dimensional electron gas confined in a HEMT channel on the device carrier mobility, is considered. The mobility dependence on temperature is also included in the model. Advantages of this model are its simplicity and straightforward implementation. Besides, it promises to be applied to quite different types of HEMTs. The model was tested. The results derived from simulations based on the proposed model are in very good agreement with the already known experimental data and theoretically obtained ones, available in literature.