Miracle-dz/UniFAR-FTUs huggingface dataset:
Reflections on PSI: Good news and bad.

Kierkegaard wrote, "life must be understood backwards, but it must be lived forwards. " This is clearly a handicap for us all! The request to write some comments on the personalized system of instruction (PSI) seemed like a good opportunity to see if looking back on what happened makes more sense than it did living through it! PSI was developed by a group deeply involved in the study oflearning theory. It was an application of reinforcement theory that took the three-term contingency seriously. My view has always been that instruction must provide for (a) presentation, (b) performance, and (c) consequences, each constantly adjusted to meet the needs of every individual student. Otherwise, the teaching is inadequate and defective. Most teaching focuses primarily, often exclusively, on presenting information. This neglects what the student does (if anything) and what feedback is provided (if any). No matter that the student is absent, confused, or utterly lost, instruction proceeds apace. This is the source of most of education's problems. PSI was devised as a process that would not leave any part of the contingency to chance. Chance produces the normal curve. Implementing the functional requirements of the three-term contingency produced the formal characteristics of PSI: mastery, specified objectives, selfpacing, small-step sequenced materials, repeated testing, immediate feedback, credit for success rather than penalty for errors, proctors, and lectures for motivation. Listing these features of PSI in this way yields a collection of terms that may appear arbitrary or capricious. It is neither. A combination of theory and practicality makes the list compelling.
An improved null model for assessing the net effects of multiple stressors on communities

Ecological stressors (i.e., environmental factors outside their normal range of variation) can mediate each other through their interactions, leading to unexpected combined effects on communities. Determining whether the net effect of stressors is ecologically surprising requires comparing their cumulative impact to a null model that represents the linear combination of their individual effects (i.e., an additive expectation). However, we show that standard additive and multiplicative null models that base their predictions on the effects of single stressors on community properties (e.g., species richness or biomass) do not provide this linear expectation, leading to incorrect interpretations of antagonistic and synergistic responses by communities. We present an alternative, the compositional null model, which instead bases its predictions on the effects of stressors on individual species, and then aggregates them to the community level. Simulations demonstrate the improved ability of the compositional null model to accurately provide a linear expectation of the net effect of stressors. We simulate the response of communities to paired stressors that affect species in a purely additive fashion and compare the relative abilities of the compositional null model and two standard community property null models (additive and multiplicative) to predict these linear changes in species richness and community biomass across different combinations (both positive, negative, or opposite) and intensities of stressors. The compositional model predicts the linear effects of multiple stressors under almost all scenarios, allowing for proper classification of net effects, whereas the standard null models do not. Our findings suggest that current estimates of the prevalence of ecological surprises on communities based on community property null models are unreliable, and should be improved by integrating the responses of individual species to the community level as does our compositional null model.
Relationship between WISC Verbal-Performance Discrepancies and Motor and Psychomotor Abilities of Children with Learning Disabilities

Thirty 9- to 14-yr. -old boys with learning disabilities were divided into three WISC IQ groups: High Verbal-Low Performance, Verbal equal to Performance, and High Performance-Low Verbal. All Ss were given a battery of motor and psychomotor tests. WISC IQ Verbal-Performance discrepancy was not a good predictor of motor and psychomotor learning disabilities.
Do all trauma patients benefit from tranexamic acid?

BACKGROUND This study tested the hypothesis that early routine use of tranexamic acid (TXA) reduces mortality in a subset of the most critically injured trauma intensive care unit patients. METHODS Consecutive trauma patients (n = 1,217) who required emergency surgery (OR) and/or transfusions from August 2009 to January 2013 were reviewed. At surgeon discretion, TXA was administered at a median of 97 minutes (1-g bolus then 1-g over 8 hours) to 150 patients deemed high risk for hemorrhagic death. With the use of propensity scores based on age, sex, traumatic brain injury (TBI), mechanism of injury, systolic blood pressure, transfusion requirements, and Injury Severity Score (ISS), these patients were matched to 150 non-TXA patients. RESULTS The study population was 43 years old, 86% male, 54% penetrating mechanism of injury, 25% TBI, 28 ISS, with 22% mortality. OR was required in 78% at 86 minutes, transfusion was required in 97% at 36 minutes, and 75% received both. For TXA versus no TXA, more packed red blood cells and total fluid were required, and mortality was 27% versus 17% (all p < 0.05). The effects of TXA were similar in those with or without TBI, although ISS, fluid, and mortality were all higher in the TBI group. Mortality associated with TXA was influenced by the timing of administration (p < 0.05), but any benefit was eliminated in those who required more than 2,000-mL packed red blood cells, who presented with systolic blood pressure of less than 120 mm Hg or who required OR (all p < 0.05). CONCLUSION For the highest injury acuity patients, TXA was associated with increased, rather than reduced, mortality, no matter what time it was administered. This lack of benefit can probably be attributed to the rapid availability of fluids and emergency OR at this trauma center. Prospective studies are needed to further identify conditions that may override the benefits from TXA. LEVEL OF EVIDENCE Therapeutic study, level IV.
Determinants of participation in state‐of‐the‐art cancer prevention, early detection/screening, and treatment trials among African‐Americans

It has been suggested that the greatest potential for reducing cancer mortality in high-risk populations may be realized through aggressive implementation of prevention, diagnostic, and state-of-the-art treatment programs and increasing participation in cancer trials. However, the national data suggest that African-Americans are most often underrepresented in such programs and/or trials. Multiple factors are assumed to contribute to this situation, but currently few studies have been conducted to validate their influence. A study focused on identifying factors that contribute to participation of African-Americans in investigational cancer programs and/or trials was therefore conducted. Two hundred twenty African-American men and women were recruited to participate in a regional survey. There was evidence to support the impact that perceptions, attitudes, and beliefs have on willingness to participate in investigational programs and/or trials. The factor having the greatest influence on willingness to participate in investigational programs and/or trials was perceived efficacy of the investigational programs and/or trials. Among this sample there was an apparent hesitancy of many to participate in research programs and/or trials. The prevailing belief that such programs and/or trials were only for those with the disease or condition under study appeared to influence their response. However, when provided information on the opportunities for participation in prevention, diagnostic, and treatment programs and/or projects for those within the general community (especially for those at higher risk) and on the benefits of participation, a much greater willingness to participate was expressed by participants.
Profligate biotin synthesis in α‐proteobacteria – a developing or degenerating regulatory system?

Biotin (vitamin H) is a key enzyme cofactor required in all three domains of life. Although this cofactor was discovered over 70 years ago and has long been recognized as an essential nutrient for animals, our knowledge of the strategies bacteria use to sense biotin demand is very limited. The paradigm mechanism is that of Escherichia coli in which BirA protein, the prototypical bi‐functional biotin protein ligase, both covalently attaches biotin to the acceptor proteins of central metabolism and represses transcription of the biotin biosynthetic pathway in response to biotin demand. However, in other bacteria the biotin protein ligase lacks a DNA‐binding domain which raises the question of how these bacteria regulate the synthesis of biotin, an energetically expensive molecule. A bioinformatic study by Rodionov and Gelfand identified a protein termed BioR in α‐proteobacteria and predicted that BioR would have the biotin operon regulatory role that in most other bacteria is fulfilled by the BirA DNA‐binding domain. We have now tested this prediction in the plant pathogen Agrobacterium tumefaciens. As predicted the A. tumefaciens biotin protein ligase is a fully functional ligase that has no role in regulation of biotin synthesis whereas BioR represses transcription of the biotin synthesis genes. Moreover, as determined by electrophoretic mobility shift assays, BioR binds the predicted operator site, which is located downstream of the mapped transcription start site. qPCR measurements indicated that deletion of BioR resulted in a c. 15‐fold increase of bio operon transcription in the presence of high biotin levels. Effective repression of a plasmid‐borne bioB‐lacZ reporter was seen only upon the overproduction of BioR. In contrast to E. coli and Bacillus subtilis where biotin synthesis is tightly controlled, A. tumefaciens synthesizes much more biotin than needed for modification of the biotin‐requiring enzymes. Protein‐bound biotin constitutes only about 0.5% of the total biotin, most of which is found in the culture medium. To the best of our knowledge, A. tumefaciens represents the first example of profligate biotin synthesis by a wild type bacterium.
Alkaloid Sequestration by Papaver somniferum Latex

Abstract The 1000 x g organelles of Papaver somniferum latex have been shown to accumulate rapidly, large quantities of alkaloids (0.05- 1 mg/mg organelle protein), particularly morphine, thebaine, codeine and papaverine and have been found to exhibit a surprising degree of specificity for the accumulation of these alkaloids. The uptake of alkaloid is independent of temperature and does not show a requirement for ATP 10-3 ᴍ, Mg2+ 10-3 ᴍ, or KCl 10-3 ᴍ. It is unaffected by known ATPase inhibitors (chlormadinone acetate 2.5 × 10-5 ᴍ, N,N-dicyclohexylcarbo- diimide 5 × 10-4 ᴍ and sodium vanadate 10-4 ᴍ) but showed considerable increase in morphine accumulation in the presence of 4-chloromercumbenzoate 5 x 10-4 ᴍ, while N-methylmaleimide 5 × 10-4 ᴍ had no effect, and carbonylcyanide 4-(trifluoromethoxy)phenylhydrazone 5 × 10-4 ᴍ caused a reduction (ca. 30%) of morphine uptake. An acid medium, pH 4.5-5.5, also results in decreased morphine uptake.
Clinicopathologic Spectrum of the So-Called Calcifying Odontogenic Cysts: A Study of 21 Intraosseous Cases With Reconsideration of the Terminology and Classification

The so-called calcifying odontogenic cyst (COC) represents a heterogeneous group of lesions that exhibit a variety of clinicopathologic and behavioral features. Because of this diversity, there has been confusion and disagreement on the terminology and classification of these lesions. We reviewed the clinicopathologic features of 21 intraosseous cases that were previously diagnosed as COC or under related diagnostic terms. Based on the biologic behavior, the lesions of the present series were divided into three subgroups: cyst, benign tumor, and malignant tumor. Sixteen cases (nine men and seven women) proved to be unicystic lesions with (five cases) or without associated odontoma. The lining epithelium of the cystic lesions fulfilled the histologic criteria for COC proposed by the World Health Organization, and their overall clinicopathologic features were consistent with that of developmental odontogenic cysts. The age of patients from the cyst group peaked at the second decade. The maxilla was affected more often (69%) than the mandible, with a predilection for the canine-premolar region (62.5%). Thirteen patients with follow-up information revealed no recurrence following enucleation. The four cases in the benign tumor group had variable clinicopathologic features. Two cases were solid tumors consisting of ameloblastoma-like sheets of odontogenic epithelium that contained ghost cells/calcification foci and juxtaepithelial dentinoid. Both patients experienced multiple recurrences following conservative surgeries. The other two lesions contained typical areas of COC and other types of odontogenic tumors (one ameloblastoma and one odontogenic myxofibroma). All four lesions occurred in the mandible and were relatively large. In the present series one case identified as malignant tumor arose from a previously benign COC. The tumor shared some features of COC (ghost cell foci and dystrophic calcification) but also had prominent mitotic activity, nuclear and cytoplasmic pleomorphism, areas of tumor necrosis, and infiltrative/destructive growth. Recognizing the extreme diversity in clinicopathologic features and biologic behavior among the so-called COCs, we suggest that the term COC should be used to specifically designate the unicystic lesions with or without an associated odontoma, i.e., lesions of the cyst group, and other related lesions identified as benign tumor and malignant tumor should be termed and classified separately. A tentative scheme with respect to the terminology and classification for this group of disparately behaving lesions was herein proposed to reflect the likely difference of their nature.
Attitudes toward Use of Hearing Protection Devices and Effects of an Intervention on Fit-Testing Results

This study assessed attitudes toward the use of hearing protection devices (HPDs) and the effect of an educational intervention on fit-testing results by comparing personal attenuation ratings (PAR50) before and after the intervention. Employees (n = 327) from a large metal container manufacturer at four geographic locations were tested with a field attenuation estimation system (FAES) to identify workers (n = 91) requiring intervention. PAR50 values significantly increased from baseline to post-intervention (p < .001, 15.1 to 26.9) and at the 6-month follow-up (p < .001, 95% confidence interval = −11.2, −6.3). Perceived self-efficacy scores for using HPDs significantly declined from baseline to post-intervention (p = .006, 95% confidence interval = 0.3, 1.9), but were not significantly related to PAR50. Therefore, a FAES can assist the occupational health nurse to identify workers at high risk (low PAR50), teach proper fit and use of HPDs, and improve hearing protector selection.
Interrelationship between peripheral arterial occlusive disease, carotid atherosclerosis and flow mediated dilation of the brachial artery.

AIM Atherosclerosis is considered a systemic disease. Therefore, in patients with atherosclerotic disease effects on various sections of the arterial system are expected. The aim of our study was to determine whether patients with evident peripheral arterial occlusive disease (PAOD) of the lower limbs have any subclinical functional or structural arterial wall changes in other sections of the arterial system. METHODS The study included 54 patients with PAOD, Fontaine stage II and a claudication distance from 50 to 500 m (average 250+/-170 m). Their mean age was 64. None of them had any symptoms or signs of coronary or cerebrovascular atherosclerosis (CVD). The control group consisted of 50 healthy volunteers with a mean age of 64 years without any risk factors of atherosclerosis. In all subjects the carotid intima-media thickness (IMT), was measured, the presence of atherosclerotic plaques in the carotid artery (CA) was registered and the endothelium-dependent dilation capability of the brachial artery (BA) during reactive hyperemia was measured using the B-mode ultrasound technique. RESULTS The average IMT was significantly greater in PAOD patients than in controls (0.8+/-0.2 mm vs 0.6+/-0.1 mm, p<0.001). In patients atherosclerotic plaques in the CA were also more numerous than in controls (38 vs 4, p<0.001). The IMT of patients was related to body mass index (BMI), ankle-brachial pressure index (ABI), LDL cholesterol and to the number of atherosclerotic plaques. In PAOD patients flow-mediated dilation of the BA was significantly lower than in controls (7.2+/-4.9% vs 12.3+/-2.1%, p<0.001). The dilation capability of the BA was linearly related to the BMI, ABI and IMT. CONCLUSION The results of our study show that PAOD patients without clinical evidence of CVD have morphological changes of the CA, increased IMT and numerous atherosclerotic plaques. Furthermore, in PAOD patients flow-mediated endothelium-dependent dilation of the peripheral arteries is decreased. These results support the hypothesis that atherosclerosis is a generalized disease, leading to functional and structural changes in several segments of the arterial system.
Alveolar bone loss in obese subjects.

BACKGROUND Obesity was found to be significantly associated with periodontal disease prevalence as measured by probing depth and clinical attachment loss. The aim of this study was to examine if obesity correlates with chronic periodontitis as diagnosed by radiographic alveolar bone loss. METHOD Four hundred subjects > or =18 years old were included; 200 with body mass index (BMI) > or =30 kg/m2 (obese) and 200 with BMI < 25 kg/m2 (non-obese). Alveolar bone loss was determined from full mouth radiographs for each subject. Logistic regression models were used to estimate the association of obesity and periodontitis. RESULTS Obesity was found to be significantly associated with periodontitis in the uni-variate regression analysis (OR = 2.37, 95% CI, 1.55-3.63). After adjusting for age, gender, smoking, employment, diabetes, marital status, and number of teeth present, obese subjects were found to be 1.86 times more likely to have periodontitis (95% CI, 0.99-3.51) than non-obese ones. When the sample was stratified based on age, the multivariate association was statistically significant among individuals < 40 years of age (OR = 2.67, 95% CI, 1.09-6.58) while among individuals > or = 40 years of age the association was statistically insignificant (OR = 1.06, 95% CI, 0.57-1.95). Stratifying the sample based on gender and smoking status revealed a stronger association among females than males (OR = 3.14 vs. 1.95) and among non-smokers than smokers (OR = 3.36 vs. 2.22). CONCLUSIONS Obesity is associated with increased prevalence of periodontitis as measured by radiographic alveolar bone loss, especially among younger individuals. Prevention and management of obesity may be considered to promote better systemic and periodontal health.
Clonogenicity of Human Endometrial Epithelial and Stromal Cells1

Abstract The human endometrium regenerates from the lower basalis layer, a germinal compartment that persists after menstruation to give rise to the new upper functionalis layer. Because adult stem cells are present in tissues that undergo regeneration, we hypothesized that human endometrium contains small populations of epithelial and stromal stem cells responsible for cyclical regeneration of endometrial glands and stroma and that these cells would exhibit clonogenicity, a stem-cell property. The aims of this study were to determine 1) the clonogenic activity of human endometrial epithelial and stromal cells, 2) which growth factors support this clonogenic activity, and 3) determine the cellular phenotypes of the clones. Endometrial tissue was obtained from women undergoing hysterectomy. Purified single- cell suspensions of epithelial and stromal cells were cultured at cloning density (300–500/cm2) in serum medium or in serum- free medium supplemented with one of eight growth factors. Small numbers of epithelial (0.22%) and stromal cells (1.25%) initiated colonies in serum-containing medium. The majority of colonies were small, containing large, loosely arranged cells, and 37% of epithelial and 1 in 60 of stromal colonies were classified as large, comprising small, densely packed cells. In serum-free medium, transforming growth factor-α (TGFα), epidermal growth factor (EGF), platelet-derived growth factor-BB (PDGF-BB) strongly supported clonogenicity of epithelial cells, while leukemia-inhibitory factor (LIF), hepatocyte growth factor (HGF), stem-cell factor (SCF), insulin-like growth factor-I (IGF- I) were weakly supportive, and basic fibroblast growth factor (bFGF) was without effect. TGFα, EGF, PDGF-BB, and bFGF supported stromal cell clonogenicity, while HGF, SCF, LIF, and IGF- I were without effect. Small epithelial colonies expressed three epithelial markers but not stromal markers; however, large epithelial colonies showed little reactivity for all markers except α6-integrin. All stromal colonies contained fibroblasts, expressing stromal markers, and in some colonies, myofibroblasts were also identified. This analysis of human endometrium has demonstrated the presence of rare clonogenic epithelial and stromal cells with high proliferative potential, providing the first evidence for the existence of putative endometrial epithelial and stromal stem cells.
Molecular diversity of the genetic loci responsible for lipopolysaccharide core oligosaccharide assembly within the genus Salmonella

The waa locus on the chromosome of Salmonella enterica encodes enzymes involved in the assembly of the core oligosaccharide region of the lipopolysaccharide (LPS) molecule. To date, there are two known core structures in Salmonella, represented by serovars Typhimurium (subspecies I) and Arizonae (subspecies IIIA). The waa locus for serovar Typhimurium has been characterized. Here, the corresponding locus from serovar Arizonae is described, and the molecular basis for the distinctive structures is established. Eleven of the 13 open reading frames (ORFs) are shared by the two loci and encode conserved proteins of known function. Two polymorphic regions distinguish the waa loci. One involves the waaK gene, the product of which adds a terminal α‐1,2‐linked N‐acetylglucosamine residue that characterizes the serovar Typhimurium core oligosaccharide. There is an extensive internal deletion within waaK of serovar Arizonae. The serovar Arizonae locus contains a novel ORF (waaH) between the waaB and waaP genes. Structural analyses and in vitro glycosyltransferase assays identified WaaH as the UDP‐glucose:(glucosyl) LPS α‐1,2‐glucosyltransferase responsible for the addition of the characteristic terminal glucose residue found in serovar Arizonae. Isolates comprising the Salmonella Reference Collections, SARC (representing the eight subspecies of S. enterica) and SARB (representing subspecies I), were examined to assess the distribution of the waa locus polymorphic regions in natural populations. These comparative studies identified additional waa locus polymorphisms, shedding light on the genetic basis for diversity in the LPS core oligosaccharides of Salmonella isolates and identifying potential sources of further novel LPS structures.