Competency-Based Education and Federal Student Aid

Competency-based education is increasingly popular because of the flexibility it provides for students seeking a postsecondary credential. Current federal student aid, however, is geared toward supporting students in traditional, time-based degree programs. This paper discusses why current approaches to federal student aid are not supportive of competency-based degree programs and explores how federal statute and regulations could be changed, in ways that are not reliant on time and credit hours, to disburse aid to students while minimizing fraud

Point Set Registration via Particle Flow Filtering

This thesis project presents an innovative registration algorithm using the particle flow filter. This is the first known approach to image registration using the particle flow filter. The particle flow filter is a Bayesian filter that uses particles to represent probability densities. Others have approached image registration as a Bayesian filtering problem; however, none have used the particle flow filter. The particle flow filter is not constrained to the highly restrictive unimodal, linear, and Gaussian assumptions of many Bayesian filters such as the Kalman filter. The particle flow filter works for any probability density function. Additionally, the particle flow filter is computationally more efficient than other multimodal filters such as the better-known particle filter. Unlike the particle filter, the particle flow filter does not require particle resampling or importance weight updates. Rather, the proposal density is formed by flowing the a priori probability density to the a posteriori using the Fokker-Planck equation. Moreover, the particle flow filter is more parallelizable than the particle filter. Regarding image registration, the particle flow filter is more robust to noise and outliers than other methods. The particle flow filter algorithms were implemented in MATLAB for both 2D and 3D rigid body point-set registration. Additionally, the particle filter method proposed by and iterative closest point algorithms were implemented for comparison. All three registration techniques were tested with a high degree of initial misalignment and noise. For the same alignment accuracy, the new particle flow filter algorithms were 244% faster than the particle filter for certain challenging problems. For the same alignment time, the particle flow filter reduced misalignment by as much as 35% compared to the particle filter. The particle flow filter achieved 100% alignment with enough particles, and reduced misalignment by as much as 75% over that of iterative closest point. These results demonstrate that image registration via the particle flow filter significantly outperforms the particle filter and iterative closest point algorithms in the presence of noise and a high degree of initial misalignment. Future areas of research for particle flow filter image registration include deformable registration and GPU parallelization

Layer-Resolved Ultrafast XUV Measurement of Hole Transport in a Ni-TiO2-Si Photoanode

Metal-oxide-semiconductor junctions are central to most electronic and optoelectronic devices. Here, the element-specificity of broadband extreme ultraviolet (XUV) ultrafast pulses is used to measure the charge transport and recombination kinetics in each layer of a Ni-TiO2-Si junction. After photoexcitation of silicon, holes are inferred to transport from Si to Ni ballistically in ~100 fs, resulting in spectral shifts in the Ni M2,3 XUV edge that are characteristic of holes and the absence of holes initially in TiO2. Meanwhile, the electrons are observed to remain on Si. After picoseconds, the transient hole population on Ni is observed to back-diffuse through the TiO2, shifting the Ti spectrum to higher oxidation state, followed by electron-hole recombination at the Si-TiO2 interface and in the Si bulk. Electrical properties, such as the hole diffusion constant in TiO2 and the initial hole mobility in Si, are fit from these transient spectra and match well with values reported previously

Manifestações orais da sífilis

The past decade has shown a significant rise in the prevalence of infective syphilis in the developed world, and striking increases in its frequency have occurred in Eastern Europe, particularly the UK, and in the US. Although oral manifestations of syphilis are most likely to be observed during secondary disease, all stages of the disease can give rise to oral lesions. Significant oral lesions such as gumma-associated bony destruction and a possible predisposition to oral squamous cell carcinoma are associated with tertiary disease. Since the prevalence of infective syphilis in heterosexuals has been increasing, there has now been a gradual rise in the number of children born with congenital syphilis. Consequently, the congenital disease gives rise to dental anomalies as well as bone, skin, and neurological anomalies of the face. The aim of this report is to review syphilis-related oral lesions, as well as to summarize the relations between human immunodeficiency virus (HIV) and syphilis.A última década tem mostrado um aumento importante na prevalência de sífilis infecciosa nos países desenvolvidos e epidemias surgiram na Europa ocidental, particularmente no Reino Unido, bem como nos EUA. Embora as manifestações orais da sífilis sejam mais freqüentes na fase secundária da doença, todos os estágios podem apresentar lesões orais. A fase terciária da doença está associada a lesões orais significativas tais como destruição óssea associada à goma sifilítica e uma possível predisposição ao carcinoma espinocelular. Com o aumento da prevalência da sífilis infecciosa, há também um aumento gradual de crianças nascidas com sífilis congênita. Consequentemente esta patologia leva a anomalias faciais de ordem dentária, óssea, dermatológica e neurológica. O objetivo deste artigo é revisar as lesões orais associadas á sífilis, bem como discorrer brevemente sobre a relação entre a infecção pelo vírus da imunodeficiência humana (human immunodeficiency virus - HIV) e a sífilis

Coherent Phonons in Antimony: an Undergraduate Physical Chemistry Solid-State Ultrafast Laser Spectroscopy Experiment

Ultrafast laser pump-probe spectroscopy is an important and growing field of physical chemistry that allows the measurement of chemical dynamics on their natural timescales, but undergraduate laboratory courses lack examples of such spectroscopy and the interpretation of the dynamics that occur. Here we develop and implement an ultrafast pump-probe spectroscopy experiment for the undergraduate physical chemistry laboratory course at the University of California Berkeley. The goal of the experiment is to expose students to concepts in solid-state chemistry and ultrafast spectroscopy via classic coherent phonon dynamics principles developed by researchers over multiple decades. The experiment utilizes a modern high-repetition rate 800 nm femtosecond Ti:Sapphire laser, split pulses with a variable time delay, and sensitive detection of transient reflectivity signals. The experiment involves minimal intervention from students and is therefore easy and safe to implement in the laboratory. Students first perform an intensity autocorrelation measurement on the femtosecond laser pulses to obtain their temporal duration. Then, students measure the pump-probe reflectivity of a single-crystal antimony sample to determine the period of coherent phonon oscillations initiated by an ultrafast pulse excitation, which is analyzed by fitting to a sine wave. Due to the disruption of in-person instruction caused by the COVID-19 pandemic, during those semesters students were provided the data they would have obtained during the experiment to analyze at home. Evaluation of student written reports reveals that the learning goals were met, and that students gained an appreciation for the field of ultrafast laser-induced chemistry

Xerostomia: an Update

Kserostomija može znatno utjecati na oralno zdravlje i kvalitetu života. Mnogobrojne nove terapije stalno se razvijaju i vrjednuju, ali općenito i dalje se teško liječe bolesti žlijezda slinovnica smještenih u podlozi. Važno je kod svih bolesnika s dugotrajnom kserostomijom obaviti pretrage koje će otkriti uzrok i bolesnicima omogućiti odgovarajuću profesionalnu oralnu njegu.Xerostomia can have a significant adverse effect upon oral health and quality of life. A variety of new therapies are continuously being developed and assessed, but in general the treatment of the underlying salivary gland disease remains difficult. It is important, however, that all patients with long-standing xerostomia are appropriately investigated to establish the underlying aetiology, and to receive professional oral health care

Concentrations of Polychlorinated Biphenyls (PCB’s), Chlorinated Pesticides, and Heavy Metals and Other Elements in Tissues of Belugas, Delphinapterus leucas, from Cook Inlet

Tissues from Cook Inlet beluga whales, Delphinapterus leucas, that were collected as part of the Alaska Marine Mammal Tissue Archival Project were analyzed for polychlorinated biphenyls (PCB’s), chlorinated pesticides, and heavy metals and other elements. Concentrations of total PCB’s (ΣPCB’s), total DDT (ΣDDT), chlordane compounds, hexachlorobenzene (HCB), dieldrin, mirex, toxaphene, and hexachlorocyclohexane (HCH) measured in Cook Inlet beluga blubber were compared with those reported for belugas from two Arctic Alaska locations (Point Hope and Point Lay), Greenland, Arctic Canada, and the highly contaminated stock from the St. Lawrence estuary in eastern Canada. The Arctic and Cook Inlet belugas had much lower concentrations (ΣPCB’s and ΣDDT were an order of magnitude lower) than those found in animals from the St. Lawrence estuary. The Cook Inlet belugas had the lowest concentrations of all (ΣPCB’s aver-aged 1.49 ± 0.70 and 0.79 ± 0.56 mg/kg wet mass, and ΣDDT averaged 1.35 ± 0.73 and 0.59 ± 0.45 mg/kg in males and females, respectively). Concentrations in the blubber of the Cook Inlet males were significantly lower than those found in the males of the Arctic Alaska belugas (ΣPCB’s and ΣDDT were about half). The lower levels in the Cook Inlet animals might be due to differences in contaminant sources, food web differences, or different age distributions among the animals sampled. Cook Inlet males had higher mean and median concentrations than did females, a result attributable to the transfer of these compounds from mother to calf during pregnancy and during lactation. Liver concentrations of cadmium and mercury were lower in the Cook Inlet belugas (most cadmium values were <1 mg/kg and mercury values were 0.704–11.42 mg/kg wet mass), but copper levels were significantly higher in the Cook Inlet animals (3.97–123.8 mg/kg wet mass) than in Arctic Alaska animals and similar to those reported for belugas from Hudson Bay. Although total mercury levels were the lowest in the Cook Inlet population, methylmercury concentrations were similar among all three groups of the Alaska animals examined (0.34–2.11 mg/kg wet mass). As has been reported for the Point Hope and Point Lay belugas, hepatic concentrations of silver were r

Building a Model of Collaboration Between Historically Black and Historically White Universities

Despite increases over the last two decades in the number of degrees awarded to students from underrepresented groups in science, technology, engineering, and mathematics (STEM) disciplines, enhancing diversity in these disciplines remains a challenge. This article describes a strategic approach to this challenge—the development of a collaborative partnership between two universities: the historically Black Elizabeth City State University and the historically White University of New Hampshire. The partnership, a type of learning organization built on three mutually agreed upon principles, strives to enhance opportunities for underrepresented students to pursue careers in the STEM disciplines. This article further describes six promising practices that framed the partnership, which resulted in the submission of nine proposals to federal agencies and the funding of four grants that led to the implementation, research, learning, and evaluation that followed

Ariel - Volume 2 Number 6

Editors Richard J. Bonanno Robin A. Edwards Associate Editors Steven Ager Stephen Flynn Shep Dickman Tom Williams Lay-out Editor Eugenia Miller Contributing Editors Michael J. Blecker W. Cherry Light James J. Nocon Lynne Porter Editors Emeritus Delvyn C. Case, Jr. Paul M. Fernhof