Basic Limitations Research Articles

Os Professores de Ensino Superior como Objeto de Estudo e a “Sociologia Prática”

O texto tem dois objetivos gerais: apresentar alguns resultados de pesquisa sobre professores de ensino superior como categoria social no Brasil e, também, apontar alguns problemas básicos e limites desse tipo de trabalho nas condições em pauta. No que tange aos professores de ensino superior como categoria social, são apresentados alguns resultados do exame de fontes censitárias e da aplicação de questionários. Nessa aplicação foram recortadas instituições e amostras de professores representativos de condições diferenciadas relativamente à posição social e às condições e exercício profissional. Quanto aos problemas e limites desse tipo de trabalho, são apontados especialmente aqueles decorrentes das concepções “práticas” dos usos das ciências sociais.

High intensity focused ultrasound: The fundamentals, clinical applications and research trends.

Diagnostic ultrasound has been clinically used for decades. More recently, high intensity focused ultrasound (HIFU) has been developed for therapeutic use as a non-invasive technique for tissue ablation. HIFU is also being investigated for advanced applications at the cellular level. Under guidance by magnetic resonance or ultrasound imaging, HIFU can achieve precise biological effects in tissue with a high safety profile. In this article, we discuss the basic principles, advantages and limitations of HIFU. We will also address the food and drug administration (FDA) approved clinical applications in the United States and highlight active HIFU research with promising clinical outcomes.

A study on the improvement device of the prison mother school

여성수용자에 대한 교정정책은 그들의 교정에 있어서 큰 역할을 해왔다. 그런데 우리나라의 여성수용자에 대한 교정정책은 두가지 측면에서 근본적 한계를 가져온 바 하나는 철저한 관료독점적 생산방식에 의한 관료적 한계이며 또 하나는 “여성”으로서의 여성수용자에 대한 교정정책에 치우쳐 “어머니”로서의 여성수용자에 대한 교정정책은 거의 없었다. 따라서 여성수용자에 대한 교정정책에 있어서 탈관료적 교정정책과 “어머니”측면에 초점을 맞춘 교정정책의 측면을 동시에 가지는 정책이 필요했다. 이러한 추세에 부응하는 교정가족정책의 모델이 바로 교도소아버지학교에 영향을 받아 2004년에 시작된 교도소어머니학교이다. 교도소어머니학교는 어머니의 진정한 회복과 성경적 여성상의 회복, 어머니의 영향력, 아내의 사명을 통하여 어머니수용자의 가족관계의 강화와 교화를 돕는 외부주도모형에 기반한 제3섹터모형이다. 교도소어머니학교는 어머니수용자들로부터 기존의 관료지향적 교정가족정책과는 질적으로 다른 호평을 받고 있지만 교도소어머니학교이념과 프로그램에 내재된 여러 문제점이 있다. 따라서 교도소어머니학교의 성숙된 발전을 위하여 이념, 프로그램, 공급자와 수요자측면에서 그 문제점과 개선방안을 독창적이고 학제적 접근으로 기술하였다.The correction policy for female prisoners has played on important role on their rehabilitation in Korean prison. But, korean correction policy for female prisoners has basic limits. One is the bureaucratic limit of bureaucratic production way in correction, the other is almost nothing the correction policy for female prisoners as “mother prisoners” due to bias of female prisoners as “female”. Therefore, we need a de-bureaucratic policy and “mother”-centric policy that has to be carried out simultaneously in correction policy for female prisoners in Korea. A correction family policy model that fits this correction trend is prison mother school since 2004 affected by prison father school in 2003. Korean prison mother school is the third sector model based on external model in correction service production that contributes to their rehabilitation and their restoration of family relationship throughout their restoration as “mother”, restoration of biblical female image, the influence of a mother, a mission of wife. Korean prison mother school is given a favorable reception by mother prisoners involved in prison mother school program of duranno mother school unlike existing bureaucratic correction family policy. But, korean prison mother school program and its ideology has basic inherent problems. Therefore, I insisted on its problems and desirable directions through my original interdisciplinary study in its program, ideology, supply, demand for its desirable development.

Associations between dietary protein and vitamin intake and the physical functioning of older adults with sarcopenia.

To investigate associations between dietary protein and vitamin intake and physical function status in older adults with sarcopenia. Data of 707 participants with sarcopenia aged > 60years from the National Health and Nutrition Examination Survey (NHANES) 1999-2004 were analyzed. Body composition, body mass index (BMI), physical function status, demographics, dietary intake (protein and vitamins A, C, E), lifestyle factors and comorbidities were measured, stratified by gender. Dietary levels of carbohydrate, fat and vitamin E differed significantly between genders (P < 0.05). Physical function limitations (48.5 vs. 36%; P < 0.001), basic activities of daily living (ADL) limitations (37 vs. 24.4%; P < 0.001), and instrumental ADL limitations (25.6 vs. 17.8%) were higher in women than in men. Multivariate logistic regression analysis revealed that, in males, intake of optimal amounts of vitamin C (Q3: ≥ 60.71mg/day) was associated with basic ADL limitations. In females, protein intake of more than 1.11g/kg/day was associated with both basic and instrumental ADL limitations. Only dietary or supplemental intake of vitamin C and E, but not protein, was associated with physical functioning in older males with sarcopenia. In contrast, only intake of higher amounts of protein, but not vitamins, was associated with physical functioning in older females with sarcopenia.

The Limits of Space Radiation Magnetic Shielding: An Updated Analysis

A major problem of long-duration manned missions in the deep space is the flow of high energy charged particles of solar (SPE) and galactic (GCR) origin. SPE has short duration but can be extremely intense and can lead to acute, even lethal, effects. GCR flow is much less intense but is continuous, isotropic, and more energetic; it increases the risk of carcinogenesis and can affect the nervous and cardiovascular systems, restricting the endurance of missions to few months. It is commonly believed that the problem of space radiation can be solved by surrounding the spacecraft habitats with large superconducting magnets, even though a considerable technological effort would be required. However, magnetic shielding has several basic limitations, which restrict the reduction of the radiation dose: they range from the biological effect of the particles in the high region of the GCR spectrum, higher than the shield cutoff energy, to the generation of secondary particles due to the interaction of cosmic rays with magnet and spacecraft materials. The physical and technological constraints of space radiation magnetic shields are discussed in this paper. Despite such limitations, a superconducting magnet could completely eliminate the risk due to SPE. Moreover, it could reduce the GCR adsorbed dose enough to make acceptable the risk of developing long term diseases after a return trip to Mars.

A controlled sewer system should be treated as a sampled data system with events

Arguments are presented in favor of modeling sewer systems and in particular Dutch sewer systems as a sampled data system with events. Basic limitations on controlling these systems when ignoring their hybrid nature are stated. The traditional control scheme for the Dutch systems is given as an example of event driven local control. Basic limitations on systems using a sampled data approach without an event driven component are derived. To provide context a brief description of a sampled data controller for a sewer system based on set-point tracking is given. This is followed by an explanation of how the absence of event driven control limits its effectiveness.

External Validation of Kidney Donor Risk Index Does Not Mitigate Its Basic Limitations.

External Validation of Kidney Donor Risk Index Does Not Mitigate Its Basic Limitations.

Stepwise Excavation.

The most recent inspiration for stepwise carious tissue removal in 2 stages originates from the knowhow on intralesion changes in deep carious lesions. The environmental change that takes place during the first stage of carious tissue removal is aiming for the arrest of the deep lesion, by placing a temporary restoration on top of the soft carious dentine. The cavity is optimised during the second stage for a final restoration, as potential shrinkage of the retained dentine may occur during the period of carious dentine arrestment. However, basic clinical limitations on the objective evaluation of pulp inflammation creates dilemmas in treating the deep lesions. Also, a global consensus is lacking for the definition of a so-called deep lesion. Finally, an optimal evidence goal for choosing the best approach for deep lesion treatment in adults has still not been fully defined. Taken together, it may not be a surprise that treatment variation is reported amongst general dental practitioners on deep caries treatment. Here, facts are presented supporting the treatment, including some drawbacks, as well as updated guidelines for the procedure. Recent clinical high evidence data from randomised clinical trials significantly favour the stepwise approach as a predictable and reliable treatment for well-defined deep carious lesions located in the pulpal quarter of the dentine in terms of avoiding pulp exposure, keeping the tooth vital and without the development of apical pathosis.

Chapter 25 - Neurotransplantation therapy

Neurotransplantation may be a promising approach for therapy of cerebellar diseases characterized by a substantial loss of neurons. Neurotransplantation could rescue neurons from degeneration and maintain cerebellar reserve, facilitate cerebellar compensation, or help reconstruct damaged neural circuits by cell substitution. These mechanisms of action can be of varying importance according to the type of cerebellar disease. Neurotransplantation therapy in cerebellar ataxias is still at the stage of experimental studies. There is currently little knowledge regarding cerebellar patients. Nevertheless, data provided by experiments in animal models of cerebellar degeneration and both clinical studies and experiences in patients with other neurologic diseases enable us to suggest basic principles, expectations, limitations, and future directions of neurotransplantation therapy for cerebellar diseases.

An inerter-based active vibration isolation system

This paper presents a theoretical study on passive and active vibration isolation schemes using inerter elements in a two degree of freedom (DOF) mechanical system. The aim of the work is to discuss basic capabilities and limitations of the vibration control systems at hand using simple and physically transparent models. Broad frequency band dynamic excitation of the source DOF is assumed. The purpose of the isolator system is to prevent vibration transmission to the receiving DOF. The frequency averaged kinetic energy of the receiving mass is used as the metric for vibration isolation quality. It is shown that the use of inerter in the passive and active vibration isolation schemes considered enhances the isolation effect.

The application of the principles of the theory of shakedown to the calculation of pavement layers of granular materials in shear

In the report ways of application of the theory of shakedown of material to calculation of coverings and the bases of pavements from the granulated materials are considered. The basic limits of shakedown are given, which include the limits of resilient, elastic and plastic shakedown. The results of three-axis tests are given, on the basis of which the character of accumulation of residual deformation is divided into damped, steady and progressive. These data allow to predict the nature of deformation and provide damped deformation of the granular material, limiting the stress at the most dangerous point.

Passive and active vibration isolation systems using inerter

This paper presents a theoretical study on passive and active vibration isolation schemes using inerter elements in a two degree of freedom (DOF) mechanical system. The aim of the work is to discuss basic capabilities and limitations of the vibration control systems at hand using simple and physically transparent models. Broad frequency band dynamic excitation of the source DOF is assumed. The purpose of the isolator system is to prevent vibration transmission to the receiving DOF. The frequency averaged kinetic energy of the receiving mass is used as the metric for vibration isolation quality. It is shown that the use of inerter element in the passive vibration isolation scheme can enhance the isolation effect. In the active case, a feedback disturbance rejection scheme is considered. Here, the error signal is the receiving body absolute velocity which is directly fed to a reactive force actuator between the source and the receiving bodies. In such a scheme, the so-called subcritical vibration isolation problems exist. These problems are characterised by the uncoupled natural frequency of the receiving body larger than the uncoupled natural frequency of the source body. In subcritical vibration isolation problems, the performance of the active control is limited by poor stability margins. This is because the stable feedback gain is restricted in a narrow range between a minimum and a maximum. However, with the inclusion of an inerter in the isolator, one of the two stability margins can be opened. This enables large, theoretically unlimited negative feedback gains and large active damping of the receiving body vibration. A simple expression for the required inertance is derived.

Markov based transition probability geostatistics in groundwater applications: assumptions and limitations

Markov based transition probability geostatistics (MTPG) for categorical variables, as implemented by the methodological framework introduced by Carle and Fogg (Math Geol 29(7):891–918, 1997) and extended thereafter, have been extensively applied for the three-dimensional (3D) statistical representation of hydrofacies in real-world aquifers, and the conditional simulation of 3D lithologies for groundwater flow and transport simulations. While conceptually simple and easy to implement, conditional simulation using the MTPG approach is not limitation free. However, to the best of our knowledge, there is no study that raises such concerns in the light of theoretical arguments and numerical findings. That said, the purpose of this study is twofold: (1) present a brief and coherent overview of the basic theory, fundamental assumptions, and limitations of the MTPG methodological framework, and (2) assess its capabilities on the basis of a simple two-dimensional test-case, using large ensembles of stochastic realizations. Contrary to real-world 3D aquifers, where the actual geology is unknown, and the quality of the simulations can be assessed solely on the basis of semi-quantitative arguments using properly selected sets of stochastic realizations, test-cases allow for direct quantitative assessments based on the application of statistical measures to large ensembles of synthetic realizations. Our analysis and obtained results show that stochastic modeling of actual geologies using the MTPG approach of Carle and Fogg (1997), is characterized by simplifying assumptions and theoretical limitations, with the simulated random fields exhibiting statistical structures that strongly depend on the problem under consideration and the modeling assumptions made, leading to increased epistemic uncertainties in the obtained results.

What can we see with IVIM MRI?

Intravoxel Incoherent Motion (IVIM) refers to translational movements which within a given voxel and during the measurement time present a distribution of speeds in orientation and/or amplitude. The IVIM concept has been used to estimate perfusion in tissues as blood flow in randomly oriented capillaries mimics a pseudo-diffusion process. IVIM-based perfusion MRI, which does not require contrast agents, has gained momentum recently, especially in the field oncology. In this introductory review the basic concepts, models, technical requirements and limitations inherent to IVIM-based perfusion MRI are outlined, as well as new, non-perfusion applications of IVIM MRI, such as virtual MR Elastography.

Molecular detection of minimal residual disease in multiple myeloma.

Despite the significantly higher complete remission rates and improved survival achieved in the last decade, multiple myeloma (MM) patients continue to relapse due to persistence of minimal residual disease (MRD). Generally, MRD refers to persistence of low levels of disease in the order of one tumour cell in ≥105 normal cells. Currently, molecular and immunophenotypic techniques are employed for MRD detection. This review focuses on MRD detection by molecular techniques, including allele-specific oligonucleotide polymerase chain reaction (ASO-PCR), next-generation sequencing (NGS) and digital PCR (dPCR), in addition to a brief description of, and comparison with, multiparameter flow cytometry. The basic principles, technical advantages and limitations, and the clinical impact of all three molecular techniques are reviewed and compared. They all have a sensitivity of at least 10-5 , among which ASO real-time quantitative PCR is the most well-standardized, and NGS carries the highest sensitivity and applicability, while dPCR is still under investigation. Furthermore, molecular MRD negativity is a favourable prognostic factor for survival of patients with MM. However, several challenges inherent to molecular detection of MRD still remain to be overcome, particularly false negativity and failure to detect extramedullary disease. Finally, detection of MRD from peripheral blood remains challenging.

Low-Adhesion Coatings Provide Novel Gas-Hydrate-Mitigation Strategy

This article, written by Special Publications Editor Adam Wilson, contains highlights of paper OTC 27874, “Low-Adhesion Coatings as a Novel Gas-Hydrate-Mitigation Strategy,” by Erika Brown, SPE, Sijia Hu, Shenglong Wang, and Jon Wells, Colorado School of Mines; Matthew Nakatsuka and Vinod Veedu, SPE, Oceanit Laboratories; and Carolyn Koh, SPE, Colorado School of Mines, prepared for the 2017 Offshore Technology Conference, Houston, 1–4 May. The paper has not been peer reviewed. Copyright 2017 Offshore Technology Conference. Reproduced by permission. When certain thermodynamic conditions exist in oil- and gas-production flowlines, gas-hydrate plugs can form and greatly restrict flow. One potential strategy for hydrate management involves allowing hydrates to form but mitigating their ability to deposit on the flowline walls by deploying a low-adhesion, protective surface coating on the inside wall of the flowline. In this study, two coatings were produced and evaluated to determine their effect on hydrate adhesion onto carbon-steel surfaces. Introduction In order to test the adhesion of hydrates to the two low-surface-energy coatings, micromechanical-force (MMF) apparatuses were used at low and high pressures. MMF apparatuses have been used historically to investigate both hydrate/hydrate interparticle forces and hydrate/surface interactions. The primary mechanism of hydrate cohesion and adhesion has been determined to be capillary bridging. Many of the parameters in capillary bridge theory can be altered through the modification of the system (e.g., the addition of surfactants or other chemicals or modification of the hydrate or solid sur-face). Hydrate/surface interactions have been studied previously; however, the surfaces used in these previous adhesion studies were always either stainless-steel or mineral surfaces, such that surface degradation by corrosion was not taken into account. In addition to MMF studies measuring adhesion forces, experiments were performed in a rocking cell to observe more-macroscopic effects of the coatings on deposition. Rocking-cell tests give a simulated flow environment and may provide insight into how the coatings respond in the bulk, rather than single-particle measurements performed with an MMF apparatus. Materials An omniphobic-coating system was developed to protect metallic surfaces against corrosion and accumulation of oil and gas precipitates such as carbonate and sulfide scales. The coating consists of a composite polymer coating that provides a low-interfacial-energy exterior with a fixed base that is impermeable to both water and olefin phases. By acting as a barrier to wetting and chemical contact with the protected surface, this coating provides protection against extreme acidic and basic chemicals and limits pitting corrosion in oxygenated and anaerobic carbonic acid environments. Additionally, the low-surface-energy exterior minimizes wetting, reduces drag/turbulence in mixed flows, and limits any surface features that could act as nucleation sites for precipitate formation and adhesion.

A study on countermeasures of juvenile delinguency through assault at Busan girls middle school

최근 부산여중생 폭행사건의 잔인함이 언론에 의해 집중 보도되면서 소년범죄와 소년법의 문제점이 사회적 이슈로 크게 대두되었다. 그런데 선행연구들은 소년범죄의 대책으로 양적 관점, 법적 관점, 행정적 관점 그리고 실현이 불가능한 시민공동체의 회복과 사회의 관심 등을 주장하여 학제적, 실효적 측면에서 근본적 한계를 보이고 있다. 따라서 본 논문에서는 전문가들의 주장과 다른 독창적 관점에서 이번 사건과 관련된 소년사법정책의 개선방향을 제시하였다. 개선방안 으로는 이념적 측면에서는 교정복지와 사법복지의 필요성을 제시했다. 법적 측면에서는 소년법의 개정과 학교폭력예방 및 대책에 관한 법률의 폐지등을 제시했고 조직적 측면에서는 관료독점적 소년사법레짐의 완화방안을 제시했다. 또한 학교전담경찰제도의 폐지와 교육청 소속의 보안교사제도 도입을 제시하였다. 또한 소년사법관료조직의 권위적 문화의 해체와 외부통제의 제도화 및 민영 보호관찰소, 민영 소년원 민영레짐 등을 제시하였다. 그리고 채용방식의 일대 혁신을 제안하였다. 또한 소년을 둘러싼 생태적 측면의 개선방안을 제시하였다.Social issues of juvenile laws and juvenile delinguency have became a big prblem through concentrated reports about cruelty of assault at Busan girls middle school by press. But many existing studies of it showed basic limits in effective perspective and interdisciplinary views because their studies of it insisted on guantative views. legal views, administration views and unrealizable rehabilitation of society inclusive of social concern. Therefore, I asserted my original desirable device of korean juvenile justice related to the assault at busan girls middle school against existing studies. I assered the necessity of correctional welfare, judicial welfare in korean juvenile justice policy in idealogic aspect and abolition of korean school violence prevention and countermeasures law and revision of korean juvenile law in legal aspect and mitigation measures of bureaucracy monopolistic juvenile justice regime in systematic aspect and safety teacher system under the jurisdiciton of the education office through abolition of SPO(school Police Officer). I asserted the dissolution of authority culture in juvenile justice bureaacracy and the systematic institulization of external controls against juvenile law enforcement agency and the necessity of private regime inclusive of private detetion center, private protection office and so on. I asserted a drastic innovation of government reecruitment way in juvenile justice and desirable device of ecological aspect around boys(girls).

Advances in Electronics Prompt a Fresh Look at Continuous Wave (CW) Nuclear Magnetic Resonance (NMR)

Continuous Wave Nuclear Magnetic Resonance (CW-NMR) was a popular method for sample interrogation at the birth of magnetic resonance but has since been overlooked by most in favor of the now more popular pulsed techniques. CW-NMR requires relatively simple electronics although, for most designs, the execution is critical to the successful implementation and sensitivity of the system. For decades there have been reports in the literature from academic groups showing the potential of magnetic resonance relaxation time measurements in industrial applications such as the production of food and drink. However, the cost, complexity and power consumption of pulsed techniques have largely consigned these to the literature. Advances in electronics and developments in permanent magnet technology now require a fresh look at CW-NMR to see if it is capable of providing cost effective industrial solutions. In this article, we review the electronics that are needed to undertake a continuous wave NMR experiment starting with early designs and journeying through the literature to understand the basic designs and limitations. We then review the more recent developments in this area and present an outlook for future work in the hope that more of the scientific community will take a fresh look at CW-NMR as a viable and powerful low-cost measurement technique.

Sources of Inherent Powers in International Adjudication

This chapter contributes to the debate about the sources of inherent powers in international adjudication. First, it contemplates the broader issue of whether the use of these powers amounts to exercising, or exceeding, an adjudicative body’s proper function. We argue the distinguishing feature of inherent powers is that they are “necessary” or “essential” judicial powers. There are also potentially basic limitations found in international law that restrict the disputing parties’ ability to take way certain inherent powers from an adjudicative body. Second, this chapter emphasizes the key role that constitutive instruments play in shaping the inherent powers of international courts and tribunals, which should alleviate the concerns about the legitimacy of these powers. Commentators typically favour one of the approaches to the sources of inherent powers in international adjudication, relying either on general principles, on the status or function of international courts, or on implied powers. We contend that these approaches do not conflict. Inherent powers can be derived from multiple sources: they can be express, they can be discretionary, they can be implied from the judicial function, or they can be rule-based with a grounding in general principles. Inherent powers are thus partly overlapping and all four sources can and do co-exist.

Ultra-broadband and planar sound diffuser with high uniformity of reflected intensity

Schroeder diffusers, as a classical design of acoustic diffusers proposed over 40 years ago, play key roles in many practical scenarios ranging from architectural acoustics to noise control to particle manipulation. Despite the great success of conventional acoustic diffusers, it is still worth pursuing ideal acoustic diffusers that are essentially expected to produce perfect sound diffuse reflection within the unlimited bandwidth. Here, we propose a different mechanism for designing acoustic diffusers to overcome the basic limits in intensity uniformity and working bandwidth in the previous designs and demonstrate a practical implementation by acoustic metamaterials with dispersionless phase-steering capability. In stark contrast to the existing production of diffuse fields relying on random scattering of sound energy by using a specific mathematical number sequence of periodically distributed unit cells, we directly mold the reflected wavefront into the desired shape by precisely manipulating the local phases of individual subwavelength metastructures. We also benchmark our design via numerical simulation with a commercially available Schroeder diffuser, and the results verify that our proposed diffuser scatters incident acoustic energy into all directions more uniformly within an ultra-broad band regardless of the incident angle. Furthermore, our design enables further improvement of the working bandwidth just by simply downscaling each individual element. With ultra-broadband functionality and high uniformity of reflected intensity, our metamaterial-based production of the diffusive field opens a route to the design and application of acoustic diffusers and may have a significant impact on various fields such as architectural acoustics and medical ultrasound imaging/treatment.