cssi/SciSciGPT-SciSciNet huggingface dataset:
Clonal analysis of vertebrate myogenesis: III. Developmental changes in the muscle-colony-forming cells of the human fetal limb☆

Abstract The cell lineage of developing human limb muscle has been investigated by means of an in vitro clonal assay. Single cells capable of forming differentiated muscle colonies have been detected within the prospective leg muscle region as early as the 36th day of human development (Streeter's Horizon XVI). At this stage clonable myoblasts account for 14% of the total colony-forming cells. The relative proportion of clonable myoblasts increases rapidly during subsequent fetal development and attains a plateau level of approximately 90% by the 100th day of development. The 90% plateau level persists at least until day 172. By correlating the percent muscle colony differentiation with clonal plating efficiency and with the number of single cells derived from the total limb muscle region of fetuses of different ages, an estimate of the actual number of clonable myoblasts within the developing limb musculature is obtained. Sequential changes within the muscle cell lineage have been further dissected by the temporal analysis of age-dependent medium effects on muscle colony differentiation. The analysis indicates that clonable myoblasts derived from early fetuses are sensitive to medium conditions to which older muscle-colony-forming cells are relatively insensitive. In addition, fusing and nonfusing colonies have been classified into recognizable morphological types whose relative proportions are observed to change during limb development. The results are correlated with human limb morphogenesis and skeletal muscle histogenesis and an operational model of muscle cell lineage is proposed.
Sublattice magnetization in Tb D 2 -crystalline electric field effects

The temperature dependence of the sublattice magnetization in Tb${\mathrm{D}}_{2}$ has been measured by neutron diffraction. A sharp increase in sublattice magnetization is observed at ${T}_{N}$. Calculations that take into account the combined effects of the molecular field and crystalline electric field have been performed. These calculations show that the sharp increase in sublattice magnetization is due to a first-order phase transition at ${T}_{N}$, which accounts for \ensuremath{\sim}0.3 of the saturated sublattice magnetization.
Bioavailability of Egg Yolk Iron Measured by Hemoglobin Regeneration in Anemic Rats

Biological availability of egg yolk iron and effect of egg yolk on absorption of iron from the reference salt, ferrous sulfate, were evaluated in hemoglobin repletion assays with anemic rats. Three measures of response, hemoglobin concentration, gain in hemoglobin iron content, and gain in carcass iron content were related to total dietary iron intake by regression analyses. Relative biological value (RBV) of yolk iron, in diets without ascorbic acid, compared to that of the reference salt was 85%. RBV of egg iron was equivalent to ferrous sulfate iron in diets containing 1 g ascorbic acid per kilogram of diet. Increasing increments of egg yolk in diets containing ascorbic acid had no significant effect on utilization of iron from the reference salt as measured by gain in hemoglobin or carcass iron content during the regeneration period. Stimulation of iron utilization from egg yolk by ascorbic acid was mild in these studies and was less in diets containing 32 mg/kg of egg yolk iron than in those containing 15 mg/kg of iron from egg.
Lymphedema: patient and provider education: current status and future trends.

BACKGROUND The majority of patients schedules for breast surgery or radiation therapy for breast carcinoma do not receive basic information about the risk of lymphedema or its treatment. METHODS A review of the literature documenting patient and provider education on the risk, prevention and treatment of lymphedema was undertaken. RESULTS Formal education about lymphedema is not a part of the training of most medical and allied health professionals. Thus, patients do not receive information about the risk, prevention, or treatment of lymphedema. CONCLUSIONS Educational strategies for patients and providers need to be developed and implemented. Cancer 1998;83:2874-2876. © 1998 American Cancer Society.
Use of aspirin and statins for the primary prevention of myocardial infarction and stroke in patients with human immunodeficiency virus infection

This retrospective, cross-sectional study evaluated whether HIV-infected patients received aspirin and statins for the primary prevention of myocardial infarction and stroke. Among the 258 patients included, 50.4% (n = 130/258) of the patients had a high risk of myocardial infarction and 14% (n = 36/258) of stroke. Overall, 43.1% (n = 56/130) and 50% (n = 18/36) of the patients were prescribed aspirin for the primary prevention of myocardial infarction and stroke, respectively. Among the patients who required statin therapy, 42.5% (n = 34/80) and 37.1% (n = 13/35) of patients received it for the primary prevention of myocardial infarction and stroke, respectively. The patients who had hypertension (odds ratio 3.8, 95% confidence interval 1.5–10.9) and diabetes mellitus (odds ratio 5.6, 95% confidence interval 2.6–12.4) were more likely to receive aspirin. Interventions are needed to improve provider awareness of the use of aspirin and statins in the primary prevention of myocardial infarction and stroke i...
Professional Role Orientations and Conflict Strategies

■ This paper explores the social action effects of the role orientations of social workers. A bureaucratic orientation is found to be conservatizing; a client orientation, radicalizing; and a professional orientation—when taken alone—is neither. When coupled with agency or client orientations, however, professionalization intensifies the conservatizing effects of agency orientation and the radicalizing effects of client orientation. Some possible explanations and implications are offered. ■
Delay analysis for packet trains over computer communication networks

A model for traffic arrival in a computer network is analyzed. This model is based on a train arrival process in which the traffic between each node pair consists of a certain number of trains, each having a random number of packets. With this scheme, the number of overhead bits per packet is reduced. The processing time at each node is reduced, because each node needs to make only one routing decision per train and does not need to make a separate routing decision for each packet. The scheme described can cope with the ever increasing amount of data being transferred over computer networks by decreasing processing times while maintaining maximum packet size restrictions. The model accurately describes the dependence suggested by observed correlation between successive arrivals of a train. The aggregate arrival process that results from multiplexing N sources to a multiplexer is characterized in detail. The relation of the proposed model to delay congestion and buffer sizes is described. >
Interactions between retroactive-interference and context-mediated treatments that impair Pavlovian conditioned responding

In Pavlovian fear conditioning, context-mediated decrements in conditioned responding (e.g., the US preexposure effect) can counteract competition between cues trained together (e.g., overshadowing). Two experiments were conducted using rats in a conditioned lick suppression preparation to determine whether context-mediated competition also counteracts competition between cues trained separately (retroactive interference, or RI). In Experiment 1, a combination of degraded contingency and RI treatments produced less of a decrement in conditioned responding than did either of those treatments alone. Experiment 2 showed that RI treatment attenuates the normally deleterious effect of trial massing. The results suggest that empirical similarities are shared by interference between cues trained apart and competition between cues trained together.
Rectal prolapse following posterior sagittal anorectoplasty for anorectal malformations.

Abstract Purpose Rectal prolapse is a known postoperative problem in children with anorectal malformations. The aims of this study were to determine the incidence of significant rectal prolapse (>5 mm), to objectively quantify its predisposing factors, and to offer recommendations as to its prevention and surgical treatment. Methods The authors reviewed their series of 1619 patients with anorectal malformations; 1169 underwent primary posterior sagittal anorectoplasty (PSARP) at their institution between 1980 and 2002, and complete records were available for 833. The series was analyzed for incidence of prolapse, type of anorectal malformation, status of the sacrum, muscle quality, associated vertebral and spinal anomalies, and postoperative constipation. A specific technique for prolapse repair was used. Results Of 833 patients, 45 developed significant rectal prolapse (3.8%). The mean age at the time of PSARP was 0.73 years (range, 0.19-5 years). The average time to recognition of prolapse following PSARP was 13.1 months. Of these 45 patients, 32 required surgical repair and of those, 3 required a second surgical repair. The incidence of prolapse varied by complexity of anorectal defect: cloaca (6.2%), rectobladder neck fistula (6.8%), rectourethral fistula (5.4%), rectovestibular fistula (1.2%), rectal atresia (0%), and rectoperineal fistula (0%). There was a significantly increased incidence of prolapse in patients with a low muscle quality score and in patients with vertebral anomalies (20% vs 3.2%). The presence of a tethered cord and an abnormal sacral ratio did not correlate with an increased incidence of prolapse. Twenty-two patients developed prolapse following colostomy closure, and of these, 12 (55%) suffered from constipation. Conclusions The overall incidence of significant rectal prolapse following PSARP is low. Prevention of prolapse with the PSARP technique may be because of key technical steps. Patients with higher anorectal malformations, poorer muscle quality, and vertebral anomalies had a greater risk of developing postoperative rectal prolapse. The presence of tethered cord and quality of the sacrum were not predictive of postoperative prolapse. Constipation seems to be a factor in the development of prolapse.
Thermogravimetric Analysis of the Oxidation of Multiwalled Carbon Nanotubes: Evidence for the Role of Defect Sites in Carbon Nanotube Chemistry

Thermogravimetric analysis (TGA) has demonstrated that multiwalled nanotubes (MWNTs) annealed at 2200 to 2800 °C are more air stable than as-produced MWNTs, diamond, graphite, and annealed diamond. The annealed MWNTs are similar in stability to annealed graphite. Defect sites along the walls and at the ends of the raw MWNTs facilitate the thermal oxidative destruction of the nanotubes. Thermal annealing removes these defects, thereby providing MWNTs with enhanced air stability.
Network awareness and application adaptability

In this paper, we argue that pervasive applications need to be aware of and adaptive to network conditions. We begin with an overview of three software projects in which we are currently involved, and highlight network awareness and application adaptability as a common thread among them. We argue that these features stem from the fundamental architectural principles of the Internet. We generalize our experience and elaborate on the principles for developing network awareness and adaptable applications.
The Strategies of Modeling in Biology Education

Modeling, like inquiry more generally, is not a single method, but rather a complex suite of strategies. Philosophers of biology, citing the diverse aims, interests, and disciplinary cultures of biologists, argue that modeling is best understood in the context of its epistemic aims and cognitive payoffs. In the science education literature, modeling has been discussed in a variety of ways, but often without explicit reference to the diversity of roles models play in scientific practice. We aim to expand and bring clarity to the myriad uses of models in science by presenting a framework from philosopher of biology Jay Odenbaugh that describes five pragmatic strategies of model use in the biological sciences. We then present illustrative examples of each of these roles from an empirical study of an undergraduate biological modeling curriculum, which highlight how students used models to help them frame their research question, explore ideas, and refine their conceptual understanding in an educational setting. Our aim is to begin to explicate the definition of modeling in science in a way that will allow educators and curriculum developers to make informed choices about how and for what purpose modeling enters science classrooms.
Friction of Aromatic Thiols in Contacts of Different Adhesive Strength

We have used friction force microscopy to study the boundary friction of thiophenol and 2-napthalenethiol monolayers on gold. The strength of the adhesion was altered by working in dry N2 gas or in ethanol. A contact mechanics model developed by Sridhar, Johnson and Fleck1,2 (SJF) for a thin, compliant elastic film confined between stiffer substrates was used to evaluate the data in systems with higher adhesion.Copyright © 2007 by ASME
Working with emotion in educational intergroup dialogue

Abstract As a form of multicultural education, intergroup dialogue is one method to improve intergroup relations. Furthermore, this form of experiential education inevitably elicits emotional responses to diversity and social justice issues. The theory and research, however, supporting its pedagogy lack a comprehensive framework for working with emotion. Recent empirical and theoretical work on emotion in intergroup interaction gives us some guidance in conceptualizing the centrality and complexity of emotional content and processes in intergroup contact. Additionally, ample evidence exists for the primacy of affect in the regulation of social relationships from the parent–child dyad to intergroup interactions. Most empirical work on affect in intergroup relations primarily focuses on assessing reactions to imagined or actual, one-time laboratory encounters and examines the reactions of only dominant group members. In contrast to experimental work, intergroup dialogue involves complex dynamics within the context of structured, sustained, face-to-face conversation among real people of dominant and subordinate social identity groups. Recommendations to improve intergroup contact include intervention at the level of emotion. Although it does not focus systematically on the affective layer, intergroup dialogues’ philosophy and structure prime the ground to do so. This paper proposes a set of principles to work with emotion in intergroup dialogue that would provide ways (1) to foster overall positive intergroup contact, (2) to work effectively with negative affect and resistance as integral and not subversive to positive intergroup interactions, (3) to attend to the force that ambivalence exerts on intergroup interaction, and (4) to work with facilitators’ affective processes. Implications for research are also discussed.
Multicolor neural network using cascaded color LCTVs

One of the important aspects of a neural network is the exploration of the spatial content of the object under observation in this connection. We shall present a color optical neural network using inexpensive package-size liquid crystal televisions (LCTVs). By introducing a color encoding technique in conjunction with a conventional white light source, a multicolor neural net is synthesized. We have shown that by exploiting the spectral component of the LCTVs storage capacity of the neural net can be improved. Simulations as well as experimental results obtained from the proposed LCTV color neural net are provided, in which the effects due to noise and due to color crosstalk are addressed.
Nitric Oxide Transport in Lymphatic Vessels

The lymphatic system plays a vital role in maintaining proper physiological function in the body. Its removal of proteins and other particulate matter from the tissue spaces is particularly important for the body’s prevention of extracellular edema [1]. After fluid is absorbed by the initial lymphatics, it is transported to lymph nodes where filtration occurs. In addition, the lymphatic system serves as a common pathway of initial metastases to regional lymph nodes for certain types of cancers [2]. Thus, the characterization of mass transport in the lymphatic system could lead to unprecedented insight into the treatment of such pathologies.© 2011 ASME
Amino-Terminal Blocking Group and Sequence of the Animal Fatty Acid Synthase

We have cloned and sequenced the cDNA encoding the chicken fatty acid synthase. Based on the nucleotide-derived amino acid sequence of the chicken synthase, the N-terminal sequences are highly conserved among animal species, suggesting that translation of the animal synthases initiates with the same ATG codon. Like other fatty acid synthases, the NH2-terminal sequence of the chicken enzyme is blocked. We have isolated and purified the blocked NH2-terminal peptide from a tryptic digest of chicken synthase and have established that the blocking group is an acetyl group. The sequence of the native tryptic peptide confirmed the cDNA-derived amino acid sequence and suggested that all animal synthases begin with this homologous sequence. We developed simple procedures that can be used to isolate and characterize any blocked NH2-terminal peptide.
Modeling the longitudinal variation in the post‐sunset far‐ultraviolet OI airglow using the SAMI2 model

[1] Recent global-scale observations of the low-latitude airglow bands associated with the equatorial ionospheric anomaly (EIA) have revealed a longitudinal variation in the brightness and latitude of the peak airglow emission. For vernal equinox conditions, both of these display a wave number-four pattern when plotted in a constant-local-time frame. It has been proposed that variations in the neutral-wind driven dynamo electric fields from the E-region are responsible for this pattern. Additionally, measurements of the electric fields in the E-region have shown a wave number-four pattern similar to that of the EIA. Here we use the SAMI2 model, that includes a detailed description of ion photochemistry and transport, to demonstrate that the recently observed zonal variations in the E-region dynamo electric fields are sufficient to explain the observed variation in brightness and latitude of the airglow bands for these conditions. The vertical drifts associated with E-region dynamo fields in the SAMI2 model are modified to produce simulations that represent the locations of a maximum and minimum in the wave number-four pattern. The simulated airglow changes such that the brightness of the maximum case is ∼40% higher than the peak in the minimum case and the latitude of the peak brightness in the maximum case is located 3° poleward of the peak in the minimum case. Both of these results compare favorably with, and even exceed, the observed variations. This result adds quantitative support to the above stated mechanism. The effect of changes in the drifts at different local time periods on the nighttime airglow is also assessed. It is seen that changes at all local time periods make a significant contribution to the total change in the airglow, with the most significant being close to local noon and during the late afternoon.
Dual functions of the signal peptide in protein transfer across the membrane

Most secretory proteins in both prokaryotic and eukaryotic cells are synthesized from a precursor with an amino-terminal extension of 20 to 25 amino acid residues called a signal peptide. These signal peptides are removed during translocation of the secretory proteins across the membrane. When two precursor structures are fused, the internalized second signal peptide was found to exert two different roles, depending upon either the distance between the two signal peptides, or whether the first signal peptide functions cotranslationally or posttranslationally. One role is to function as the usual signal peptide to translocate the protein downstream of the internal signal peptide. The other role is to function as a stop-transfer signal to create a transmembrane protein with the second signal peptide anchoring the protein in the membrane.
Efficient Geo-distributed Data Processing with Rout

Big data processing undoubtedly represents a major challenge of this era. While several programming models and supporting systems have been proposed to deal with such data in so-called “cloud” infrastructures, they all exhibit the same limitation: all data is assumed to be located in one datacenter. This limitation results from cloud vendors promoting the abstraction of omnipresent computing and storage resources. When dealing with data distributed across datacenters, programmers currently have two options: (1) copying all data to a single datacenter easily becomes tedious if done manually as the original dataset is updated, leads to repetitive copying if performed as part of a program, and is sometimes impossible; (2) writing multiple variants of the same program, with consolidation occurring at different points varying by characteristics of the task (e.g., input sub-dataset sizes) is laborious and does not help determining the most appropriate one for a given run. This paper introduces geo-distributed data structures and operations for expressing data processing tasks taking place across datacenters. We describe the design and implementation of such data structures and operations for the PigLatin language. We illustrate the performance benefits of our geodistributed data structures and operations through several benchmarks, showing up to 2× faster response times.
Angular Momentum and Polarization in Hadron Collisions up to LHC Energies

Longstanding puzzles in spin physics can be confronted at the high energies of the LHC. Heavy quarks will be produced with significant polarization, both as single spin asymmetries and through polarization correlations. Lower energy proton accelerator and leptoproduction data suggest various mechanisms within QCD for polarization phenomena that can be tested at higher energies. Observation of strange and charm hadron polarization reveals important aspects of QCD spin physics. Top quark polarization is predicted to be significant, and polarization correlations will reveal important aspects of the gluon distributions of the hadrons.
Sensitivity and Specificity for Detecting Basal Cell Carcinomas in Mohs Excisions with Confocal Fluorescence Mosaicing Microscopy

Recent studies have demonstrated the ability of confocal fluorescence mosaicing microscopy to rapidly detect basal cell carcinomas (BCCs) directly in thick and fresh Mohs surgical excisions. Mosaics of confocal images display large areas of tissue with high resolution and magnification equivalent to 2x, which is the standard magnification when examining pathology. Comparison of mosaics to Mohs frozen histopathology was shown to be excellent for all types of BCCs. However, comparisons in the previous studies were visual and qualitative. In this work, we report the results of a semiquantitative preclinical study in which 45 confocal mosaics are blindly evaluated for the presence (or absence) of BCC tumor. The evaluations are made by two clinicians: a senior Mohs surgeon with prior expertise in interpreting confocal images, and a novice Mohs fellow with limited experience. The blinded evaluation is compared to the gold standard of frozen histopathology. BCCs are detected with an overall sensitivity of 96.6%, specificity of 89.2%, positive predictive value of 93.0%, and negative predictive value of 94.7%. The results demonstrate the potential clinical utility of confocal mosaicing microscopy toward rapid surgical pathology at the bedside to expedite and guide surgery.
Mental Health Outcomes of Family Members of Oregonians Who Request Physician Aid in Dying

Oregon legalized physician aid in dying over 10 years ago but little is known about the effects of this choice on family members' mental health. We surveyed 95 family members of decedent Oregonians who had explicitly requested aid in dying, including 59 whose loved one received a lethal prescription and 36 whose loved one died by lethal ingestion. For comparison purposes, family members of Oregonians who died of cancer or amyotrophic lateral sclerosis also were surveyed. A mean of 14 months after death, 11% of family members whose loved one requested aid in dying had major depressive disorder, 2% had prolonged grief, and 38% had received mental health care. Among those whose family member requested aid in dying, whether or not the patient accessed a lethal prescription had no influence on subsequent depression, grief, or mental health services use; however, family members of Oregonians who received a lethal prescription were more likely to believe that their loved one's choices were honored and less likely to have regrets about how the loved one died. Comparing family members of those who requested aid in dying to those who did not revealed no differences in primary mental health outcomes of depression, grief, or mental health services use. Family members of Oregonians who requested aid in dying felt more prepared and accepting of the death than comparison family members. In summary, pursuit of aid in dying does not have negative effects on surviving family members and may be associated with greater preparation and acceptance of death.
Impaired Penicillin Production in Lysine Regulatory Mutants of Penicillium chrysogenum

Lysine-regulatory mutants of Penicillium chrysogenum which excrete lysine were found to be deficient in production of penicillin. A revertant recovered the ability to produce penicillin.
The Criteria for Open Access

AbstractEach proposal for Open Access (OA) has its unique combination of features; each argument for or against OA focuses on particular features or criteria. This article is intended to discuss these criteria, both individually and also as each of them contributes to the different proposals for OA. Evaluation of the proposals themselves is not attempted. This discussion is intended to be of value to the supporters of OA, in choosing which plan to adopt, and to those opposed to OA, in showing where the weaknesses do and do not lie. In other words, this article intends to improve the level of factual understanding in the ongoing discussions.
Tunable two-mirror laser interference lithography system for large-area nano-patterning

A novel laser interference lithography system with enhanced tunablility in pattern periodicity and coverage has been designed and tested for large-area nano-patterning in a wide range of a pattern frequency. The tunable feature has been achieved by using two rotational mirrors on expanded beam paths at specific angles for a designed period. With a 325 nm laser wavelength, uniform resist nano-patterns of 250, 500, and 750 nm have been experimentally demonstrated on a 4-inch silicon substrate. This new interferometer configuration offers a convenient and robust way to prepare large-area nanostructures with superior tunability in pattern periods.
Cultured Aedes albopictus mosquito cells accumulate elongation factor-1α (EF-1α) during serum starvation

We examined survival, growth and protein synthesis in mosquito cells that had been maintained for up to 21 days in serum-free medium. On polyacrylamide gels, protein bands from "starved" cells remained discrete, and despite low levels of incorporation, radiolabeled bands were detectable, suggesting that low levels of protein synthesis were sustained. A prominent band that accumulated in serum-starved cells was digested with trypsin and analyzed by tandem mass spectrometry, which identified the protein as eukaryotic elongation factor (EF)-1 alpha EF-1 alpha is well-conserved among species, and differential accumulation of EF-1 alpha in serum-starved cells was verified by western blotting using a primary antibody to the homologous protein from Trypanosoma brucei. Aside from its importance in the elongation step of protein synthesis, EF-1 alpha has been shown to have a number of non-canonical functions, including interaction with viral RNA and a potential role in apoptosis. We anticipate that the prolonged viability of mosquito cells in serum-free medium may provide a system to explore whether EF-1 alpha accumulation is an adaptive response compatible with resumption of growth in the event that nutrients are replenished, or whether the excess EF-1 alpha represents an irreversible commitment to an apoptotic pathway.
Differential effects of nitrogen mustard in vivo on the cancer and host cells in MCa‐11 tumours

We analysed the effects of nitrogen mustard (HN2) on the growth, cell cycle distributions, and ratios of tumour cells to host cells for MCa-11 tumours grown in vivo. Treatment of tumour-bearing BALB/c mice with 3 mg/kg of HN2 produced a significant slowing of MCa-11 tumour growth. Seventy-two hours after treatment in vivo with either 3 or 4 mg/kg of HN2, the host cells in the treated tumours showed a significantly decreased G0/G1 peak and an increased G2/M peak (P < 0.01), whereas the cancer cells in the treated tumours showed significant increases in the G0/G1 peak coupled with relatively decreased proportions of S and G2/M tumour cells (P < 0.001). The ratio of the total number of cancer cells to the total number of host cells in the tumours was significantly increased 72 h after HN2 administration (P < 0.01). Thirty-two days after treatment with HN2, the cell cycle distributions of the host and tumour cells in the treatment and control tumours had returned to being identical, but the ratio of the total number of cancer cells to the total number of host cells remained increased in the treated tumours (P < 0.01). These results show that the administration in vivo of HN2 can lead to entirely different cell cycle effects for the host and cancer cells in the same tumour, and that the partial growth arrest of MCa-11 tumours from HN2 treatment may be due in part to the preferential destruction of host cells rather than solely to a direct cytotoxic effect on the cancer cells.
Asymmetric synthesis of tetrabenazine and dihydrotetrabenazine.

The enantioselective synthesis of (+)-tetrabenazine (TBZ) and (+)-dihydrotetrabenazine (DTBZ), agents of significant interest for therapeutic and molecular imaging applications, has been completed in 21% (TBZ) and 16% (DTBZ) overall yield and in >97% ee from the starting dihydroisoquinoline. The synthesis utilizes Sodeoka’s palladium-catalyzed asymmetric malonate addition to set the initial stereocenter followed by a number of diastereoselective transformations to incorporate the remaining asymmetric centers.
Should risk from medical imaging be assessed in the absence of benefit and vice versa

Diagnostic radiology has an image problem. In its effort to develop a better understanding of benefit–risk in medical radiology, data on potential risks associated with medical imaging have been welcomed into the medical community. As such, risk perspectives and mantras from the occupational health profession have been adopted and applied to patients. These perspectives often focus on risk with only casual, incidental, or no reference to the benefits experienced by patients. These occupational health viewpoints have accumulated over decades, have overshadowed a very limited perspective about the benefits of medical X-rays, and have become an integrated part of our profession. This review argues that the medical profession should abandon perspectives on risk that are adopted from occupational health professions and focus on perspectives that realistically focus on the medical benefit–risk for patients.
Transcription of the Human Folylpoly-γ-glutamate Synthetase Gene

Abstract In mammals, folylpoly-γ-glutamate synthetase (FPGS) activity is found in any cell undergoing sustained proliferative phases, but this enzyme also displays a tissue-specific pattern of expression in differentiated tissues. It is now reported that the steady state levels of FPGS mRNA in normal and neoplastic cells reflect these patterns, supporting the concept that the control mechanisms underlying this distribution are transcriptional. To initiate an understanding of these interacting levels of control, we have determined the position and properties of the minimal FPGS promoter controlling transcription of the FPGS gene in human CEM leukemia cells, a line which expresses high levels of this enzyme and its mRNA. The TATA-less region immediately upstream of the major transcriptional start site previously mapped in human tumor cells, which includes several GC- and Y-boxes, functioned as a remarkably efficient promoter when used to drive expression of a luciferase reporter in transient expression studies in CEM cells. The minimal region of the FPGS promoter required for maximal transcriptional activation in CEM cells included the 80 base pairs over which the multiple transcriptional start sites were located, and the 43 base pairs immediately upstream. DNase I footprint analysis detected the binding of Sp1 at all seven of the consensus sites within the probe used, two of which are contained within the minimal promoter region. The several Sp1 sites immediately upstream of the first major transcriptional start activated transcription in Drosophilacells when cotransfected with an Sp1 construct, including those in the region which functioned as a minimal promoter in CEM cells. An additional region of the minimal promoter, situated between the two translational start codons of the FPGS gene, was bound by protein(s) from HeLa cell nuclear extracts. We conclude that transcription of the FPGS gene in CEM cells involves transactivation events over a limited upstream DNA sequence and that the FPGS promoter used in proliferating human leukemic cells has strong similarity to other TATA-less promoters that utilize tandem, closely spaced Sp1 sites to initiate transcription.
Throughput Analysis for Shallow Water Communication Utilizing Directional Antennas

Underwater communication relies on acoustic links due to its long propagation and low attenuation properties. Despite the advantages of using acoustic links over radio frequency (RF), the major drawback is the limited bandwidth of the acoustic spectrum. To circumvent this, we advocate the use of directional antennas rather than the traditional omni-directional antennas to boost the network throughput by taking advantage of the spatial spectrum. In this paper, we analyze the network throughput for shallow water communication with directional antennas. Unlike traditional line-of-sight (LOS) directional communication, our analysis will aim to factor in non-line-of-sight (NLOS) links in the throughput analysis. We will be focusing on two NLOS links; namely refracted-surface-reflected (RSR) and refracted-bottom-reflected (RBR) to study the multipath effects on the network throughput. Simulation experiments are also provided to validate the analytical results.
Using Cooperative Water Quality Data for a Holistic Understanding of Rivers and Streams: A Study of the Neponset River, Massachusetts

Water quality studies seeking to identify modes or processes of river systems often use targeted, research-designed, high-frequency data, whereas most water quality data today are collected for monitoring and reporting requirements are of low frequency and are collected through cooperative and volunteer programs. There exists in this situation an information gap between the science of understanding river system dynamics and the collection of data in most of these systems. Using data collected by volunteers in the Neponset Watershed (Massachusetts, U.S.), we demonstrate that multivariate analysis is a viable option for enhancing the use and information of spatially distributed, long-term monitoring data sets common in the United States. Additionally, the geographic, environmental, and time line information inherent in these community-maintained data leads to a more complete picture of river and stream dynamics. Principal component analyses of three distinct reaches with different channel characteristics an...
Ultrastructure of the larval salivary glands of Megaselia scalaris Loew (Diptera, Phoridae)

Each of the paired salivary glands of third instar larvae of the humpbacked fly Megaselia scalaris is a bag-like structure with a short neck region from which a single duct emerges. The two ducts form a common duct that empties into the ventral region of the pharynx near the mouthparts. The wall of the glands and ducts consists of a simple squamous epithelium that rests upon a connective tissue layer. Cells in the neck are less flattened than those found elsewhere. The basal surfaces of the cells are infolded most deeply in the neck and the least in the duct. The apical surfaces of the cells possess microvilli except in the duct where the apices of the cells are covered by a complex extracellular layer. This layer displays circularly arranged folds that accommodate a thread-like supportive structure resembling taenidial threads of tracheae. Elaborate junctional complexes are associated with the lateral surfaces of the cells. Elements of these complexes include a zonula adherens, a series of pleated septate desmosomes, and conventional desmosomes. The cytoplasm of the glandular cells is filled with RER and other organelles normally seen in cells that export proteins and mucosubstances. Secretory material found in the lumens of the glands reacts only moderately with the PAS procedure but more strongly with alcian blue and methods that demonstrate proteins. The nuclei of the glandular cells contain single large nucleoli and polytene chromosomes whose banding is rather indistinct. Treatment with EDTA produces detrimental effects on all of the foregoing ultrastructural features of the glands and ducts.
Macintosh statistical packages

Fifteen statistical packages for the Apple Macintosh computer are reviewed, and their features are listed and compared. Many do not follow the Macintosh user interface and are likely to be confusing to novices. Accuracy tests are reported for several programs.
MR imaging assessment of the lateral head of the gastrocnemius muscle: prevalence of segmental anomalous origins in children and young adults

Background Variations in the lower extremity musculature have been identified, including an anomalous origin of the medial head of the gastrocnemius muscle. Anomalies of the lateral head of the gastrocnemius muscle (LGN) have been less frequently described, especially in children.
Structure and Dynamics of Surfactant and Hydrocarbon Aggregates on Graphite: A Molecular Dynamics Simulation Study

We have examined the structure and dynamics of sodium dodecyl sulfate (SDS) and dodecane (C12) molecular aggregates at varying surface coverages on the basal plane of graphite via classical molecular dynamics simulations. Our results suggest that graphite-hydrocarbon chain interactions favor specific molecular orientations at the single-molecule level via alignment of the tail along the crystallographic directions. This orientational bias is reduced greatly upon increasing the surface coverage for both molecules due to intermolecular interactions, leading to very weak bias at intermediate surface coverages. Interestingly, for complete monolayers, we find a re-emergent orientational bias. Furthermore, by comparing the SDS behavior with C12, we demonstrate that the charged head group plays a key role in the aggregate structures: SDS molecules display a tendency to form linear file-like aggregates while C12 forms tightly bound planar ones. The observed orientational bias for SDS molecules is in agreement with experimental observations of hemimicelle orientation and provides support for the belief that an initial oriented layer governs the orientation of hemimicellar aggregates.
Insulin growth factor signaling mediates neuron-like differentiation of adipose-tissue-derived stem cells.

Our previous study showed that adipose tissue-derived stem cells (ADSC) could be induced by isobutylmethylxanthine (IBMX) to differentiate into neuron-like cells. In the present study, ADSC were treated with IBMX in the presence or in the absence of each of eight specific inhibitors of different signaling pathways (JAK/STAT, PKA, PI3K, MEK, Wnt/Frizzled, ERK/MAPK, TGF-β, and insulin growth factor [IGF]-I). PPP, a specific inhibitor of IGF-I signaling, was the only inhibitor that showed significant inhibition of IBMX-induced ADSC neuronal differentiation, as determined by changes in cell morphology in the initial screening. Further examination by immunofluorescence staining showed that the neuronal marker, β-III-tubulin, was highly induced in IBMX-treated ADSC, and the induction was significantly suppressed by PPP. Western blotting, followed by densitometry showed that PPP suppressed IBMX-induced β-III-tubulin expression by 43%, 88%, and 84% when used to treat the cells for 1, 3, and 24 hr, respectively. Treatment of ADSC with IBMX also led to the phosphorylation of IGF-I receptor at tyrosine 1136 (Y1136), as determined by immunofluorescence staining with an antibody that reacts specifically with Y1136. This effect was also abrogated by PPP. Thus, the IBMX-induced neuron-like differentiation of ADSC is mediated by IGF signaling through the phosphorylation of IGF-IR at Y1136.
The Thread of Life: Toraja Reflections on the Life Cycle

The Thread of Life: Toraja Reflections on the Life Cycle. Douglas W. Hollan and Jane C. Wellenkamp. Honolulu: University of Hawaii Press, 1996. xii. 239 pp., appendixes, notes, glossary, references, index.
Effect of intracarotid nitric oxide on primate cerebral vasospasm after subarachnoid hemorrhage

✓ The continuous release of nitric oxide (NO) is required to maintain basal cerebrovascular tone. Oxyhemoglobin, a putative spasmogen, rapidly binds NO, implicating loss of NO in the pathogenesis of cerebral vasospasm after subarachnoid hemorrhage (SAH). If vasospasm is mediated by depletion of NO in the vessel wall, it should be reversible by replacement with NO. To investigate this hypothesis, the authors placed blood clots around the right middle cerebral artery (RMCA) of four cynomolgus monkeys; four unoperated animals served as controls. Arteriography was performed before and 7 days after surgery to assess the presence and degree of vasospasm, which was quantified in the anteroposterior (AP) projection by computerized image analysis. On Day 7, cortical cerebral blood flow (CBF) in the distribution of the right MCA was measured during four to six runs in the right internal carotid artery (ICA) of brief infusions of saline followed by NO solution. Arteriography was performed immediately after completin...
Gardner's syndrome with duodenal adenomas, gastric adenomyoma and thyroid papillary—Follicular adenocarcinoma

A case of a woman with Gardner's syndrome, originally manifested by multiple adenomatous polyps of the colon, is presented. She underwent subtotal colectomy at 14 years of age. Over the next 15 years she had a composite odontoma, an impacted super-numerary tooth, two epidermal inclusion cysts, multicentric papillary—follicular adenocarcinoma of the thyroid, two tubulovillous adenomas of the duodenum in which argyrophilic cells were a prominent feature, and an adenomyoma of the gastric antrum. The presence of all of these lesions in one patient expands the spectrum of lesions seen with Gardner's syndrome and supports the concept of a generalized abnormality of growth regulation as the cause of the syndrome.
Prophage recombination in transformation -negative mutants of Haemophilus influenzae.

Summary Homoimmune superinfection of rapidly growing HPl-lysogenic Haemophilus influenzae leads to the formation of a few tandem double lysogens while that of competent cells gives rise to the formation of single and double lysogens with genetically altered prophages (prophage recombination; Stuy and Hoffmann, 1971 , Stuy and Hoffmann, 1970 ). Insertion of the superinfected phage genome appeared to occur normally in all but one of a number of mutant cultures. Prophage recombination was much reduced in three transformation-negative mutants.
Screening mammography and late-stage breast cancer: a population-based study.

Background: Among 50- to 69-year-old women, randomized clinical trials show breast cancer mortality reductions from screening mammography. However, few studies examine the long-term health effects and outcomes from screening mammography in community practice. The purpose of this study was to evaluate one approach for determining the effectiveness of screening mammography, as it is practiced in community settings, and to measure the prevalence of prior screening mammography among women with incident breast cancer. Methods: This study was a population-based survey of the general community. Participants were 406 women with breast cancer diagnosed in 1993. The main outcome measure was breast cancer, late stage at diagnosis or fatal within 2 to 3 years of diagnosis. Results: Sixty-four (57.7%) of 111 women with late-stage and 123 (42.1%) of 292 women with early-stage breast cancer did not have a screening mammogram in the 4 calendar years (1989–1992) before diagnosis. Relative to women with early-stage breast cancer, mammography nonuse in 1989–1992 was significantly more frequent among women with late-stage breast cancer (age-adjusted odds ratio 2.3, 95% confidence interval 1.3–4.3). Prior mammography was particularly infrequent among 42 women with breast cancer incident in 1993 and fatal before January 1996. Conclusions: Prior mammography among women with late-stage or fatal breast cancer was relatively infrequent. Late-stage or fatal breast cancer lacking prior mammography constitutes a missed public health opportunity. Also, this population-based study showed the expected association between prior mammography and late-stage or fatal breast cancer. These results are consistent with the effective practice of mammography in a community setting. The results illustrate and validate a public health approach that uses prior mammography histories among women with incident breast cancer to evaluate mammography penetration and quality in defined communities.
Functional Role and Affinity of Inorganic Cations in Stabilizing the Tetrameric Structure of the KcsA K+ Channel

Crystal structures of the tetrameric KcsA K+ channel reveal seven distinct binding sites for K+ ions within the central pore formed at the fourfold rotational symmetry axis. Coordination of an individual K+ ion by eight protein oxygen atoms within the selectivity filter suggests that ion-subunit bridging by cation–oxygen interactions contributes to structural stability of the tetramer. To test this hypothesis, we examined the effect of inorganic cations on the temperature dependence of the KcsA tetramer as monitored by SDS-PAGE. Inorganic cations known to permeate or strongly block K+ channels (K+, Rb+, Cs+, Tl+, NH4+, Ba2+, and Sr2+) confer tetramer stability at higher temperatures (T0.5 range = 87°C to >99°C) than impermeant cations and weak blockers (Li+, Na+, Tris+, choline+; T0.5 range = 59°C to 77°C). Titration of K+, Ba2+, and other stabilizing cations protects against rapid loss of KcsA tetramer observed in 100 mM choline Cl at 90°C. Tetramer protection titrations of K+, Rb+, Cs+, Tl+, and NH4+ at 85°C or 90°C exhibit apparent Hill coefficients (N) ranging from 1.7 to 3.3 and affinity constants (K0.5) ranging from 1.1 to 9.6 mM. Ba2+ and Sr2+ titrations exhibit apparent one-site behavior (N ≅ 1) with K0.5 values of 210 nM and 11 μM, respectively. At 95°C in the presence of 5 mM K+, titration of Li+ or Na+ destabilizes the tetramer with K0.5 values of 57 mM and 109 mM, respectively. We conclude that specific binding interactions of inorganic cations with the selectivity filter are an important determinant of tetramer stability of KscA.
Effects of Contextual Sight-Singing and Aural Skills Training on Error-Detection Abilities:

Effects of contextual sight-singing and ear training on pitch and rhythm error detection abilities among undergraduate instrumental music education majors were examined. Experimental (n1 = 15) and ...