cssi/SciSciGPT-SciSciNet huggingface dataset:
Spanish Medical Interpreters' Management of Challenges in End of Life Discussions.

Abstract Objective Professional medical interpreters facilitate patient understanding of illness, prognosis, and treatment options. Facilitating end of life discussions can be challenging. Our objective was to better understand the challenges professional medical interpreters face and how they affect the accuracy of provider-patient communication during discussions of end of life. Methods We conducted semi-structured interviews with professional Spanish medical interpreters. We asked about their experiences interpreting end of life discussions, including questions about values, professional and emotional challenges interpreting these conversations, and how those challenges might impact accuracy. We used a grounded theory, constant comparative method to analyze the data. Participants completed a short demographic questionnaire. Results Seventeen Spanish language interpreters participated. Participants described intensive attention to communication accuracy during end of life discussions, even when discussions caused emotional or professional distress. Professional strains such as rapid discussion tempo contributed to unintentional alterations in discussion content. Perceived non-empathic behaviors of providers contributed to rare, intentional alterations in discussion flow and content. Conclusion We found that despite challenges, Spanish language interpreters focus intensively on accurate interpretation in discussions of end of life. Practice Implications Provider training on how to best work with interpreters in these important conversations could support accurate and empathetic interpretation.
Machine Learning for Demand Estimation in Long Tail Markets

Random coefficient multinomial logit models (Berry et al. 1995) are widely used to estimate customer preferences from sales data. However, these estimation models can only allow for products with positive sales; this selection leads to highly biased estimates in long tail markets--i.e., markets where many products have zero or low sales. Such markets are increasingly common in areas such as online retail and other online marketplaces. In this paper, we propose a two-stage estimator that uses machine learning to correct for this bias. Our method first uses deep learning to predict the market shares of all products, where the neural network's structure mirrors the random coefficient logit model’s data generating process. In the second stage, we use the predictions of the first stage to re-weight the observed shares in a way that corrects for the induced bias and maintains the causal interpretation of the structural model. We show that the estimated parameters are consistent in the number of markets. Our method performs well on simulated long tail data, producing accurate estimates of customer behavior. These improved estimates can subsequently be used to provide prescriptive policy recommendations on important managerial decisions like pricing, assortment, or the introduction of new products.
Better Radiographic Reduction and Lower Complication Rates With Combined Coracoclavicular and Acromioclavicular Ligament Reconstruction Than With Isolated Coracoclavicular Reconstruction

Purpose To determine whether combined acromioclavicular (AC) ligament reconstruction and coracoclavicular (CC) ligament reconstruction without bone tunnels would improve radiographic reduction maintenance and complication rates for type III to V AC dislocations. Methods This single-institution retrospective study analyzed all patients who underwent a hybrid synthetic/graft wrap CC reconstruction without tunnels with additional AC reconstruction/repair from January 2013 to August 2019. This 26-patient cohort was compared with a 1:1 sex- and age-matched control group who underwent CC reconstruction without AC reconstruction. CC distances on postoperative radiographs were compared with normal contralateral shoulders. Results Of the 93 patients who underwent AC reconstructive surgery during this time period, 26 patients (96% male) met the inclusion criteria. The AC/CC cohort had 23.5% type III injuries, 23.1% type IV injuries, and 53.8% type V injuries, similar to the control group. Final radiographs of the operative shoulder’s CC distance were (mean ± standard deviation) 0.9 ± 4.0 mm greater than that of the contralateral shoulder (9.6 ± 8.7 mm) in the AC/CC cohort. Final radiographs of the operative shoulder’s coracoclavicular distance were 4.0 ± 4.7 mm greater than that of the contralateral shoulder (13.3 ± 9.3 mm) in the CC control group, a significant difference (P = .014). The AC/CC reconstruction group had fewer patients with a loss of reduction >5 mm (11.5% versus 38.5%, P = .025). The complication rate in the CC control group was higher than in the AC/CC cohort (30.7% versus 7.7%, P = .035). The reoperation rate was also greater in the CC control group (8 versus 1, P = .010). Conclusion This cohort study shows that the addition of AC reconstruction to CC reconstruction using synthetic tapes/grafts or allograft tissues without bone tunnels significantly improves durable radiographic outcomes, diminishes complication rates, and improves reoperation rates. Level of Evidence III, retrospective comparative study.
Global Mamas: confronting the challenges of marketing fair trade apparel to female millennials

This case presents to students the challenges that Global Mamas, a fair trade non-profit organisation, is experiencing in marketing its products to female millennials. Research has indicated that female millennials have a significant interest in purchasing fair trade products; however, there are a number of concerns that have prevented fair trade products from gaining mainstream acceptance among this consumer group. First, the case defines fair trade and discusses the growing niche market surrounding it. Second, Global Mamas is introduced and its current marketing, production, and distribution strategies are examined, as well as the current challenges Global Mamas is facing in capturing the attention and gaining the loyalty of this growing niche market. Students will be able to explain the foundational principles of fair trade and develop potential marketing strategies intended for the industry's niche market, addressing concerns they have regarding fair trade products and labelling procedures.
The Historian's Responsibility for the Future: Recording Covid-19 for the Next Generation

This is a thought piece on the roles, responsibilities, and practices of being a historian. After examples of how a life is lived in historical context, the Covid crisis is employed as the example on how to practice our craft.
Note on Warfare in Eastern Philosophy

This note on warfare summarizes treatises by Chinese (e.g., Sun Tzu, The Art of War, ca. 500 BC) and Japanese (e.g., Miyamoto Musashi, The Book of Five Rings, 1643 AD) warriors, reviews their philosophies and leadership lessons, and offers modern applications. Excerpt UVA-S-0304 Rev. Nov. 7, 2019 Note on Warfare in Eastern Philosophy Preface This note on warfare summarizes treatises by Chinese (e.g., Sun Tzu, The Art of War, ca. 500 BC) and Japanese (e.g., Miyamoto Musashi, The Book of Five Rings, 1643 AD) warriors, reviews their philosophies and leadership lessons, and offers modern applications. Background . . .
Acute Toxicity in Patients Treated With Proton vs. Photon Chemoradiotherapy for Locally Advanced Head and Neck Cancer.

PURPOSE/OBJECTIVE(S) Patients undergoing concurrent chemoradiotherapy (CRT) for head and neck cancer often experience significant toxicities. Proton therapy permits decreased dose delivery to non-target structures and the potential for superior organs-at-risk sparing. The aim of this study was to evaluate if proton therapy is associated with decreased acute grade ≥3 toxicities compared to photon therapy in the setting of concurrent CRT for head and neck cancers. MATERIALS/METHODS This study included 654 adult patients with nonmetastatic, locally advanced head and neck cancer treated with definitive concurrent CRT from January 1, 2011 to April 30, 2019 at one institution. 90-day toxicity data were prospectively collected as defined by Common Terminology Criteria for Adverse Events, version 4. Acute toxicities were grouped into five categories for analysis: mucosal (mucosal infection, mucositis), oral cavity (dry mouth, dysgeusia), swallow (aspiration, dysphagia), constitutional (fatigue, anorexia, dehydration), and skin (dermatitis, edema, superficial soft tissue necrosis, alopecia) toxicities. Modified Poisson regression models with covariate adjustment were used to model toxicity risk following multiple imputation for missing covariate values. Ten hypotheses were tested. Thus, the Bonferroni multiple testing correction was applied and statistical significance was assessed at the 0.005 level. RESULTS One hundred and six patients received proton therapy and 548 received photon therapy. Patients receiving proton therapy were older (mean age [SD] 61.2 [12.2] vs 58.9 [9.30], P = 0.029) and were more likely to be HPV-positive (67.0% vs 57.0%, P = 0.036). Proton therapy patients had lower dose to the parotid glands (right mean [SD], 21.8 Gy [12.9] vs 27.9 [11.3], P < 0.001; left 23.1 Gy [12.7] vs 27.2 [11.0], P = 0.001), oral cavity (13.7 Gy [9.88] vs 28.8 [10.8], P < 0.001) and constrictor muscle (35.6 Gy [10.37] vs 43.7 [9.24], P < 0.001) compared to photon therapy patients. Charlson-Deyo comorbidity scores were similar for both groups (mean [SD] 6.18 [1.74] vs 6.40 [2.57], P = 0.39), as were the distributions for sex (P = 0.118), race (P = 0.16), cancer stage (P = 0.163), and baseline ECOG (P = 0.57). In covariate-adjusted analyses, proton therapy was associated with a significantly lower relative risk of any 90-day grade ≥3 toxicity (0.57, 95% CI 0.40-0.83, P = 0.003). For acute grade 2 toxicity proton therapy was associated with significantly reduced relative risk of oral cavity toxicity (0.74, 95% CI 0.61-0.90, P = 0.002) but higher skin toxicity (1.35, 95% CI 1.14-1.59, P = 0.0004). CONCLUSION Concurrent chemoradiotherapy with proton therapy for head and neck cancers was associated with lower dose to nontarget structures and significantly reduced acute grade ≥3 toxicity and acute grade 2 oral cavity toxicity compared to photon therapy. Grade 2 skin toxicity favored photon therapy.
Top-down control of the phase of alpha-band oscillations as a mechanism for temporal prediction

The physiological state of the brain before an incoming stimulus has substantial consequences for subsequent behavior and neural processing. For example, the phase of ongoing posterior alpha-band oscillations (8–14 Hz) immediately before visual stimulation has been shown to predict perceptual outcomes and downstream neural activity. Although this phenomenon suggests that these oscillations may phasically route information through functional networks, many accounts treat these periodic effects as a consequence of ongoing activity that is independent of behavioral strategy. Here, we investigated whether alpha-band phase can be guided by top-down control in a temporal cueing task. When participants were provided with cues predictive of the moment of visual target onset, discrimination accuracy improved and targets were more frequently reported as consciously seen, relative to unpredictive cues. This effect was accompanied by a significant shift in the phase of alpha-band oscillations, before target onset, toward each participant’s optimal phase for stimulus discrimination. These findings provide direct evidence that forming predictions about when a stimulus will appear can bias the phase of ongoing alpha-band oscillations toward an optimal phase for visual processing, and may thus serve as a mechanism for the top-down control of visual processing guided by temporal predictions.
Abstract 3369: Association Between Bi-directional Mitral Isthmus Block and Atypical Flutter Following Left Atrial Linear Ablation in Patients with Symptomatic Atrial Fibrillation

Background: Incomplete or unidirectional mitral isthmus block (MIB) during left atrial linear ablation (LALA) for atrial fibrillation (AF) may be proarrhythmic, and is the most common target for repeat ablation in patients with atypical atrial flutter (AAFL) after LALA. Objective: To determine if achieving bidirectional MIB during LALA will reduce occurrence post-ablation AAFL and/or recurrence of AF. Methods and Results: Fifty-six consecutive patients (pts), 49 males and 7 females, mean age 59±8 years, who underwent LALA for symptomatic, persistent (61%) or paroxysmal (39%) AF were evaluated. Thirty-four pts had been previously ablated, none had MIB from the first ablation. All pts underwent LALA including two encircling lesions around the right and left pulmonary veins, a line at the roof of the left atrium between the two circles, and a line from the lateral mitral valve annulus (MVA) to the left circle with adjunctive coronary sinus ablation as needed to achieve MIB. Thirty pts had an additional line from the septal MVA to the right circle. Bi-directional MIB was documented by pacing from the left atrial appendage and proximal coronary sinus. Bi-directional MIB was achieved in 38 pts (68%), with ablation in the coronary sinus required in 87.5% of pts. Thirty-seven pts underwent LALA with a standard 8 mm tip (Blazer™ or Navistar™) catheter and 19 pts with saline-irrigated catheters (ThermoCool™, Chili™). Patients were followed for 6±2 months. AAFL occurred in 15 pts (27%), and 17 pts (30%) had recurrence of AF. In pts with AAFL, 8 had documented bi-directional MIB during ablation and 7 did not. The odds of AAFL was 7.6 times higher in pts without MIB compared those with MIB (p=0.02); adjusting for age, gender, diagnosis, type of catheter, coronary sinus ablation and history of previous ablation. This study did not show similar association between recurrence of AF and MIB (p=0.5). Conclusions: Achieving bi-directional MIB will reduce incidence of post-ablation AAFL significantly. Recurrence of AF is not reduced by achieving bi-directional MIB.
Inhibitory Effect of Meclofenamate Sodium on Proteasome Activity in the Cardiac Cells and Reversal of its Effect by Antioxidants

Objective: Prolonged use of nonsteroidal anti-inflammatory drugs (NSAIDs) is reported to increase the occurrences of cardiovascular diseases (CVD). Significant proteasome inhibition is also associated with increased incidences of CVD. Hence, the effect of the NSAIDs meclofenamate sodium (MS) and naproxen sodium (NAP) on the proteasome system was investigated in H9c2 rat cardiac cells. Methods: 26S proteasome activity assays, cell viability assays, reactive oxygen species (ROS) assays, and MV151 fluorescent labelling of proteasome active sites were utilized. Results: Decreased 26S β5 chymotrypsin-like proteasome activity (30%) and β1 caspase-like activity (20%) was seen in H9c2 cells treated with 100µM MS for 24h compared to the cells treated with 500 µM NAP or vehicle. Rat heart lysates showed significant decreases in β5 activity in the presence of 50-500 µM MS. Purified proteasomes also showed decreased β5 activity in the presence of 100 µM MS. MV-151 labeling showed that this decrease in activity was no...
A Staging Process with Applications in Biology and Medicine

The staging process is not a new concept. The process existed even before the creation of man. Formation of the heavenly body, evolution of living things, advancement of civilization and of sciences, as well as the development of social structure, religious faith, political systems, etc. are all by stages. At the micro level, metamorphosis in biology and development of a fetus are good examples, each of which follows a definite staging process. This concept became eminent in recent years in survival analysis when it was recognized that development of many chronic conditions is by stages and. patients in different stages are subject to different chances of dying. It was in the study of survival analysis of such patients that a stochastic model of the staging process was formulated. We shall briefly review the staging process in terms of survival and death of chronic patients, and present its applications in carcinogenesis, fertility and epidemics.
Effect of cell physiological state on infection by rat virus.

Abstract Infection by rat virus has been studied in cultures of rat embryo cells to evaluate the Margolis-Kilham hypothesis that the virus preferentially infects tissues with actively dividing cells. An enhancement of infection was seen in cultures infected 10 hr after fresh medium was added as compared to infection of stationary cultures (infected before addition of fresh medium). Since addition of fresh medium stimulates deoxyribonucleic acid (DNA) synthesis, the number of cells per culture synthesizing DNA at the time of infection was compared with the proportion of cells which synthesized viral protein. Cells were infected before the medium change and 10 or 24 hr after the medium change and were pulse-labeled with 3H-thymidine at the time virus was added. The cells were allowed to initiate viral protein synthesis before they were fixed and stained with fluorescein-conjugated anti-rat virus serum. Fluorescence microscopy permitted both labels to be counted simultaneouly and showed that the greatest proportion of cells synthesizing viral protein were those which had incorporated 3H-thymidine at the time of infection.
Effect of alcohol on threatened premature labor.

Abstract Evidence has been accumulating that oxytocin plays a role in the initiation and maintenance of labor in the human and other species. It has been demonstrated that ethyl alcohol inhibits the release of oxytocin during parturition and lactation in the rabbit and during lactation in the human. If oxytocin is essential for human parturition, alcohol should have an effect on uterine activity in labor. Alcohol was given to 68 patients in threatened premature labor, including 52 with intact and 16 with ruptured membranes. The alcohol was given intravenously as a 9.5 per cent solution in dextrose/water. A loading dose was given during the first one or 2 hours, followed by a maintenance dose of one tenth of the loading dose per hour. Of the 52 patients with intact membranes, in 35 delivery was postponed for 3 days or more, 30 of them carrying their pregnancy to 37 weeks or more. In 10 patients, labor was arrested initially but recurred and was allowed to progress, and in 7 patients labor could not be arrested. In all 16 patients with ruptured membranes, the treatment with alcohol failed to postpone delivery significantly. However, an inhibitory effect on the uterine contractions was observed in all 68 cases, as well as in 10 cases of labor at term and in 3 cases of threatened premature labor in connection with a Shirodkar procedure. It is concluded that alcohol can inhibit the uterine activity during labor and that this presumably is due to an inhibition of the release of oxytocin from the neurohypophysis.
A Role for Shc, Grb2, and Raf-1 in FcγRI Signal Relay

The activation of the serine/threonine kinase, Raf-1, serves to connect upstream protein tyrosine kinases to downstream signaling events. We previously reported that FcgammaRI stimulation of interferon gamma-differentiated U937 cells (termed U937IF cells) induces a mobility shift in Erk2. Herein, we report that cross-linking of FcgammaRI receptor in U937IF cells induces a marked tyrosine phosphorylation of Raf-1 (10-fold increase). Tyrosine phosphorylation of Raf-1 is induced by FcgammaRI activation and not by PMA (1 microg/ml), N-formyl-Met-Leu-Phe (1 microM), calcium ionophore (1 microM), thrombin (0.05 unit/ml), FcgammaRII, or FcgammaRIII stimulation. The kinetics of Raf-1 tyrosine phosphorylation is rapid, reaching peak levels 1-2 min after FcgammaRI activation, and the tyrosine phosphorylation of Raf-1 precedes the activation of the respiratory burst. FcgammaRI cross-linking induces the tyrosine phosphorylation of Shc; tyrosine-phosphorylated Shc binds to Grb2 forming a Shc-Grb2 complex. The data provide evidence that the FcgammaRI receptor signals via the upstream activation of nonreceptor protein tyrosine kinases, which leads to the subsequent activation of Ras family GTPases and serine/threonine kinases, Raf-1 and mitogen-activated protein kinase.
A framework for dynamic constraint reasoning using procedural constraints

Many complex real-world decision problems, such as planning, contain an underlying constraint reasoning problem. The feasibility of a solution candidate then depends on the consistency of the associated constraint problem instance. The underlying constraint problems are invariably dynamic, as higher level decisions result in variables, values, and constraints being added and removed. In real-world reasoning applications, constraints may be arbitrarily complex, variables may have continuous domains, and neither variables nor values may be effectively enumerable beforehand. Such applications, therefore, present a number of significant challenges for a dynamic constraint reasoning mechanism. In this paper, we introduce a general framework for representing and reasoning about dynamic constraint networks arising from complex real-world applications. It is based on the use of procedures to represent and effectively reason about general constraints. The framework can handle arbitrary changes to the network, including the addition and deletion of variables and values. It can reason with real-valued variables, and utilize special-purpose reasoning methods, such as arithmetic problem solving, in the form of procedures. The resulting framework is based on a sound theoretical foundation, which guarantees termination and correctness.
Effects of Natural Human Antibodies against a Nonhuman Sialic Acid That Metabolically Incorporates into Activated and Malignant Immune Cells

Humans are genetically incapable of producing the mammalian sialic acid N-glycolylneuraminic acid (Neu5Gc), due to an inactivating mutation in the enzyme synthesizing it. Despite this, human cells and tissues appear capable of metabolically incorporating Neu5Gc from exogenous sources, including dietary red meat and dairy products. All normal humans studied are now shown to have circulating Abs against Neu5Gc, with marked differences in isotype levels. The question arises whether such Abs can adversely affect Neu5Gc-expressing human cells or tissues. In this study, we show that although normal human PBMC do not incorporate Neu5Gc during in vitro incubation, activated T cells do. Primary human leukemia cells and human leukemic cell lines are even more efficient at incorporation. Human sera containing naturally high levels of anti-Neu5Gc IgG Abs (hereafter abbreviated GcIg) deposited complement on Neu5Gc-expressing leukemic cells and activated T cells, but not on normal cells. The binding of GcIg resulted in complement-mediated cytotoxicity, which was inhibited by heat inactivation. Low anti-Neu5Gc IgG-containing human sera did not mediate any of these effects. Mixed killing assays confirmed the 15-fold selective killing of leukemic cells over PBMC by GcIg following Neu5Gc feeding. This approach could potentially serve as novel way to target malignant cells for death in vivo using either natural Abs or anti-Neu5Gc Abs prepared for this purpose. Further studies are needed to determine whether deposition of natural GcIg and complement can also target healthy proliferating immune cells for death in vivo following incorporation of dietary Neu5Gc.
Physiological survey of medullary raphe and magnocellular reticular neurons in the anesthetized rat.

Leung, Cynthia G. and Peggy Mason. Physiological survey of medullary raphe and magnocellular reticular neurons in the anesthetized rat. J. Neurophysiol. 80: 1630–1646, 1998. The present study was d...
Diversificação e conservação das Lecythidaceae neotropicais

As Lecythidaceae (familia da castanha-do-Para) sao arvores tropicais de planicie que atingiram sua maior diversidade em especies nos neotropicos. No Novo Mundo, a familia esta mais diversificada em habitats de terra firme na Amazonia e nas Guianas. Pouco mais de 50% de todas as especies neotropicais de Lecythidaceae sao encontradas na Amazonia, sendo a Amazonia central especialmente rica em especies. Uma unica area de 1,00 hectares, 90 Km ao norte de Manaus apresenta 38 especies diferentes de Lecythidaceae. Alem disso, um grande numero de especies de Lecythidaceae tem o centro de distribuicao na provincia floristica das Guianas. As especies de Lecythidaceae com flores actinomorficas sao mais numerosas no noroeste da America do Sul, enquanto que as especies com flores zigomorfas predominam da Amazonia central ate as Guianas. As matas costeiras do Equador e da Colombia ate o Panama abrigam sete especies de Lecythidaceae ameacadas de extincao e nove das 15 especies de Lecythidaceae que ocorrem nas matas do leste do Brasil extra-amazonico sao endemicas. Estas matas costeiras do Pacifico e do leste brasileiro devem receber alta prioridade quanto a conservacao das Lecythidaceae, porque sao nestas matas que o alto grau de endemismo coincide com extremo destamatamento.
Comparison of quasi-/pseudo-floating gate techniques

Recently, the quasi- or pseudo-floating gate (QFG) technique has been suggested by several authors to implement many of the functions of the widely used floating-gate MOS transistors technique by using ultra-high resistances to isolate a floating node. Several different ways have been suggested to implement these quasi-infinite resistors (QIRs). In this paper, several basic QIR structure are analyzed and compared, and three sources of error, dc offset, signal distortion, and signal-dependent offset, are defined. Then, through simulations and experiments, the suitability of several QIR implementations for use in various applications is compared. One implementation is shown to minimize dc offset, but voltage swing is limited to less than 0.7 V/sub pp/. Configurations using parallel connections of QIRs improve signal distortion and signal-dependent offset, but still suffer from dc offset and limited voltage swing. Series-connected QIR structures allow increased voltage swings, but typically lead to hard-to-predict offsets of up to few hundred mV because of well-substrate leakage currents. Other circuits are also analyzed.
The structure of the protein universe and genome evolution

Despite the practically unlimited number of possible protein sequences, the number of basic shapes in which proteins fold seems not only to be finite, but also to be relatively small, with probably no more than 10,000 folds in existence. Moreover, the distribution of proteins among these folds is highly non-homogeneous -- some folds and superfamilies are extremely abundant, but most are rare. Protein folds and families encoded in diverse genomes show similar size distributions with notable mathematical properties, which also extend to the number of connections between domains in multidomain proteins. All these distributions follow asymptotic power laws, such as have been identified in a wide variety of biological and physical systems, and which are typically associated with scale-free networks. These findings suggest that genome evolution is driven by extremely general mechanisms based on the preferential attachment principle.
SEASONAL CHANGES IN SPORADIC METEOR RATES

Abstract R. Lunsford and G. Zay observed 15,114 sporadic meteors between 1992 and 1996 and their data are analyzed in this report. The data reveal a distinct seasonal trend with rates from July through December being 1.31 ± 0.10 times those from January through June. After the effect of the changing direction of the apex of Earth's way is removed, it is found that the July through December rates are 3 ± 10% higher than those from January through June. The average corrected hourly rate for sporadic meteors between 1992 and 1996 is 10.7 ± 1.3 at 2:00 am local standard time under a limiting magnitude of 6.5, which is consistent with observations made between 1981 and 1991.
Patience Pays: The Quest for Restoration Projects To Compensate for Lost Use of Natural Resources for Public Recreation from the 1993 Tampa Bay Oil Spill1

ABSTRACT The public's use of natural resources for recreation can be substantially disrupted by an oil spill. Following a 1999 settlement with parties responsible for the spill, the National Oceanic and Atmospheric Administration (NOAA) and Florida Department of Environmental Protection (FDEP) (“the Trustees”), acting through a Trustee Council, finalized a restoration to offset recreational losses from the 1993 Tampa Bay oil spill. This paper describes the development of the restoration plan in cooperation with affected communities and the basis upon which specific restoration projects were chosen for inclusion in that plan, including the nexus between injured resources or lost resource services and the selected projects. The recreational restoration plan focused only on projects designed to acquire or enhance public access to natural resources for recreation. Projects selected for implementation include construction of fishing piers, public trails and walkways, enhancement of boating opportunities, and e...
Age-related decline in central cholinergic function demonstrated with scopolamine

Scopolamine hydrobromide was administered intravenously to 23 normal subjects (40–89 years) in doses of 0.1 mg, 0.25 mg, and 0.5 mg, in a doubleblind, placebo-controlled, random-order fashion. The effects of scopolamine, as compared to placebo, were assessed using a comprehensive cognitive test battery, as well as behavioral and physiological measures. Scopolamine produced the expected dose-dependent impairments in most of the cognitive functions assessed. Behavioral and physiological measures were also affected, but only minimally. More importantly, there was a significant overall correlation between age and scopolamine-impaired performances on psychomotor speed, short-term recall, visual tracking speed, visuo-motor coordination, and sequencing ability. There was, however, some inter-individual variability in this phenomenon. The results provide further evidence that cholinergically mediated cognitive functions show an increased sensitivity to scopolamine with age, albeit with heterogeneity that bears further investigation.
Role of available carbon and nitrogen in determining the rate of wheat straw decomposition

Abstract The effect of available C and N on the rate of wheat ( Triticum aestivum L.) straw decomposition by microorganisms was determined using electrolytic respirometers under laboratory conditions. Three lots of spring wheat straw containing 1.13, 0.79 and 0.18% N were used. Cold-water soluble C and N were leached from the wheat straw and the respiration from the leached and non-leached straws (1.5 g of each), with and without added N, were compared in a sand system for 881 h. The fraction of soluble C declined as straw N content declined (total soluble C was 14.0, 11.4 and 8.9%, respectively, for the three straws). The fraction of soluble N declined as straw N content declined, but the proportion of total N that was soluble varied with initial straw N content. We postulated from decomposition data for the various treatments that the amount of microbial biomass produced and the overall rate of wheat straw decomposition in the early stages is largely dependent on the size of the soluble C pool and an intermediately-available C pool that is not cold-water soluble but decomposes within the first few days of decay. Our results from this study imply that the amount of N immobilized during wheat straw decomposition is dependent on the amount of available C from both the primary and secondary pools present in the straw. The data also suggest that the soluble C pool and the intermediately-available C pool were metabolized simultaneously.
Predicting thermodynamic properties with a novel semiempirical topological descriptor and path numbers.

Group electronegativities, which take into account the influence of chemical environment, are calculated. Equilibrium electronegativity is defined on the basis of group electronegativity. Using rel...
Early weaning of southern flounder, Paralichthys lethostigma, larvae and ontogeny of selected digestive enzymes

Abstract There is considerable interest in rearing Southern flounder, Paralichthys lethostigma , for commercial production and for stock enhancement. Both goals depend upon excellent larval nutrition for the production of robust juveniles. The current use of live prey for larviculture is an expensive and time consuming process that can be alleviated by weaning larvae onto dry feed. A study was conducted to assess the potential for early weaning of southern flounder larvae onto a microdiet (MD). In addition, the activity of selected digestive enzymes was measured during ontogeny to evaluate the digestive capabilities of the larvae over time. Pancreatic enzyme activities (U larva − 1 ) were very low or undetectable at hatching and a marked increase in activity was not observed until the larvae reached 4 mm (~ 11 dph) in standard length for chymotrypsin (24–44,000) and 6 mm (~ 25 dph) for amylase ( 10.0) was not observed until after complete metamorphosis (> 11.0 mm; 40–45 dph). Feeding regimes employed for the weaning study consisted of a live feed control (C) and a combination of live feed and MD in which the addition of the MD was initiated on 11 dph and live feed terminated on 17 (T17), 23 (T23) or 29 (T29) dph. At the end of the study (35 dph), mean standard length and the percent of settled fish were significantly greater for fish in the control treatment (8.3 mm; 21.1%) than for fish fed any combination of live prey and MD (6.4 mm; 2.0%). Average survival was 27.7% and no significant differences were noted among treatments. However, the number of fish exhibiting spinal deformities, lordosis, was significantly lower in the control and T29 treatments (1.7%) than the T17 and T23 treatments (25%). The results of this study indicate that southern flounder larvae readily wean onto dry feed prior to the onset of metamorphosis. However, decreased growth and a high incidence of lordosis emphasize the need for the development of a more appropriate MD for this species when digestive enzyme activities are relatively low and gastric digestion is absent.
51 CHANGING ROOSTER SPERM MEMBRANES TO FACILITATE CRYOPRESERVATION

Cryopreservation damages rooster sperm membranes. Part of this damage is due to membrane transitioning from the fluid to the gel state as temperature is reduced. Some of this damage may be prevented by increasing membrane fluidity at low temperatures by incorporating cholesterol or unsaturated lipids into the membrane. Different concentrations of cholesterol-loaded cyclodextrins (CLC) and lipid-loaded cyclodextrins (LLC) containing 1,2-dilinoleoyl-sn-glycero-3-phosphocholine; 1,2-dilinoleoyl-rac-glycerol; and 1,2-dilinolenoyl-sn-glycero-3-phosphocholine were added to rooster sperm to determine if they improved cryopreservation. Osmotic stresses when cryoprotectants (CPA) are added to the cells before freezing and when the CPA are removed from cells after thawing also cause membrane damage. To minimize this damage, low molecular weight CPA with high membrane permeability were tested to determine their effectiveness for cryopreserving sperm. Rooster semen was collected from several birds, pooled and diluted to 800 million sperm mL–1 at 5°C in Lake's Low Temperature diluent (LLT). Sperm were treated with either LLC (0.25, 0.5, 1, 1.5, 2, 4 and 6 mg mL–1) or CLC (0.5, 1 and 2 mg mL–1) for 30 min. The sperm were diluted 1:1 with LLT containing 18% CPA, resulting in final CPA concentrations of 9%. The CPA tested were glycerol (G), methylacetamide (MA), dimethylformamide (DMF), methylformamide (MF) and ethylene glycol (EG). The sperm were frozen in liquid nitrogen vapor and stored in liquid nitrogen. Straws were thawed in 5°C water and sperm motility and membrane integrity analysed immediately. Sperm motility was measured using computer-assisted sperm analysis (CASA) and membrane integrity was analysed by flow cytometry using propidium iodide to detect cells with damaged membranes. Data were analysed by ANOVA and means separated using Student–Newman–Keuls multiple comparison test. Addition of LLC and CLC did improve sperm cryosurvival rates (P > 0.05). Using G as the CPA resulted in higher percentages of motile (54%) and viable (58%) sperm than MA (47 and 52%; P < 0.05), whereas DMF, EG and MF resulted in less than 45% motile cells (P < 0.05). In conclusion, altering sperm membrane composition using CLC and LLC did not improve post-thaw motility or viability in rooster sperm. Although MA did not protect the rooster sperm from cryodamage as effectively as G, future assays will need to determine the fertilizing capacity of sperm frozen using these CPA. We thank CSU-CVBMS for funding support.
Changes in the phase structure of the polyethylenes after long-time storage at room temperatures

The long-time crystallization of a set of polyethylenes, that have a variety of different molecular structures, has been studied under storage conditions well removed from those where partial melting or relatively rapid crystallization takes place. For high molecular weight linear polyethylenes, branched polyethylenes and ethylene copolymers a density increase of about 5% is observed. However, analysis of the Raman internal modes indicates that the core crystallinity remains constant. It is found that the density change reflects an increase in the partially ordered interfacial region at the expense of the disordered liquid-like region.
Map of retinal position onto the cross section of the optic pathway of goldfish

The position of a retinal cell is defined by the two polar coordinates: r, the distance from the optic disc, and 8, the angular (or clock-face) position. Axons of similar 8 value were labeled by the punctate application of horseradish peroxidase (HRP) to optic axons in the retina, and axons of similar rvalue were labeled by the application of this same marker to a tectal fascicle. Labeled axons were traced in serial transverse sections of the optic pathway from the retina to the tectum to learn the map of the retinal surface onto the cross section of the pathway. Retinas were flat-mounted and treated for HRP to show the retinal origins of the labeled axons. Axons of similar r were clustered together, and the fraction of the pathway's cross-sectional area occupied by the cluster was about the same as the fraction of the retinal area occupied by the group of labeled somata. Axons of similar 8 were also clustered, but the fraction of the cross-sectional area they occupied was larger than the fraction of retinal area occupied by their somata. The geometry of the clusters of labeled axons depended on the proximodistal location in the pathway. Near the retina both were stripshaped, but the location and orientation of the strip varied. Both an r-strip and a @-strip were labeled in some pathways by dual applications of HRP; the two strips were mutually orthogonal at all levels. Each of r and 8 mapped onto a separate axis. The axons from most peripheral retina (largest r) were everywhere adjacent to the pia, and axons of progressively more central retina (smaller r) were progressively more separated from the pia (except in the nerve, where the secondary fasciculation complicates the geometry by wrapping old axons in new pia). The map of the circular variable, 8, onto a line, required a discontinuity, the location of which differed, depending on the proximodistal level. From the retina to the chiasm, the discontinuity was at the ventral retinal radius (i.e., the right retinal clock-face positions were ordered 6-9-12-3-6 o'clock across the line); just central to the chiasm, the fibers reordered to put the discontinuity at the nasal radius (clock-face positions ordered 3-6-9-12-3); at the brachial bifurcation, the 3-6-9 half turned dorsally, the 9-12-3 half, ventrally. The results are discussed in the context of the growth of the pathway and compared with similar organizational plans in the optic pathways of other vertebrates.
Aluminum, copper, tin and lead as shielding materials in the treatment of cancer with high-energy electrons

Abstract During irradiation of lesions in cancer treatment with electrons, irregular field sizes are shaped by blocking off the areas to be protected usually with lead or Lepowitz metal of adequate thickness. Sometimes these blocks are placed directly on the skin. In such cases, the block should not only be of minimum weight (thickness), but also the residual dose received by the protected organs should be as small as possible. However, due to the production of bremsstrahlung, it is difficult to achieve a higher degree of attenuation unless a sufficient thickness of shielding material is used. Hence, a minimum or optimum thickness is needed to be measured. Transmission measurements are performed to determine suitable minimum thicknesses and to measure the transmission at this minimum thickness, for aluminum, copper, tin and lead for electron broad-beam field sizes 6×6, 10×10 and 20×20 cm 2 of energies 6, 12 and 20 MeV produced by a medical linear accelerator. The ratio of the measured ionization with and without the shielding material in percent is expressed as a measure of transmission. The minimum thickness is `knee' position of the transmission curves, where the dose received by the organs (residual dose) is mostly dominated by the bremsstrahlung component and any addition of shielding material is not of much advantage in achieving further appreciable shielding effect. It is noticed that at this minimum thickness the percentage dose received by the vital organs behind the shield varies from 1 to 14% of the original unshielded dose as the atomic number of the shielding material increases from 13 (aluminum) to 82 (lead) and as the electron energy of the beam increases from 6 to 20 MeV. In other words, the effectiveness of shielding decreases from 99 to 86% as the atomic number increases from 13 to 82. Depending on the treatment volume, its position and the clearance between the electron cone and the skin, the dose received by the vital organs surrounding the tumor can be minimized by choosing the optimum thickness of these elements.
Periodontal disease in the prehistoric Ipiutak and Tigara skeletal remains from Point Hope, Alaska

Two large groups of prehistoric Eskimo skeletons from Point Hope, Alaska, were evaluated for dental wear and several measures of periodontal disease. Occlusal attrition was found to increase steadily with increasing age. Crown height decreased proportionately. Assessing periodontal disease by inspecting apparent alveolar recession was judged ineffective due to possible supereruption. Infrabony pockets, the result of severe localized periodontal disease indicated that in Ipiutak people between the ages of 25 and 30, and Tigara people between 35 and 40, more dental sites were affected by periodontal disease than were not. This suggests a cultural, genetic, or dietary difference between the two groups. Male/female differences were slight in all parameters studied.
Nonnegative spectraloid matrices

Abstract Several characterizations are given for certain nonnegative matrices having equal spectral and numerical radii. Some of these results are applied to stochastic matrices.
Finite difference method for calculating magnetic field components off-median plane using median plane field data

Abstract Given a magnet with midplane symmetry, the field is totally determined if one knows the field in the midplane. A new finite difference method for calculating the field from discrete data in the midplane is described. Because data to be processed are obtained from measurements with noise, the method for evaluating derivatives is required to suppress the high frequency signals effectively, while maintaining reasonable accuracy for low frequencies. First-order and second-order differentiators for a uniform mesh are designed. As a test, they are applied to the magnetic field produced by two magnetized iron bars where the exact analytical expression for the magnetic field is known and also they are applied to the same field data when a small amount of noise is superimposed. And, finally, they are applied to the measured magnetic field of the K1200 super conducting cyclotron.
On the tribology of the MAX phases and their composites during dry sliding: A review

Abstract By now, it is fairly well established that the layered hexagonal MAX phases are thermodynamically stable nanolaminates displaying unusual and sometimes unique properties. These phases are so-called because they possess a Mn + 1AXn chemistry, where n is 1, 2, or 3, M is an early transition metal element, A is an A-group element and X is C or N. They are highly damage tolerant, thermal shock resistant, readily machinable, and with Vickers hardness values of 2–8 GPa, are anomalously soft for transition metal carbides and nitrides. Some of them display a ductile–brittle transition at temperatures > 1000 °C, while retaining decent mechanical properties at these elevated temperatures. Moreover, their layered nature suggests they may have excellent promise as solid lubricant materials. Recently, first generation MAX Phase based composites shafts were successfully tested against Ni-based superalloy at 50,000 rpm from RT till 550 °C during thermal cycling in a foil bearing rig. This study further demonstrates the potential of MAX Phases and their composites in different tribological applications. The main objective of this review is to present recent progress, and consequently develop a comprehensive understanding about the tribological behavior of MAX Phases and their composites. We are also proposing a way of classifying the different tribofilms to understand the complex tribological behavior of these solids over a wide range of different experimental conditions.
Anomalous Origin of Left Coronary From Right Pulmonary Artery in Hypoplastic Left Heart Syndrome

An infant with hypoplastic left heart syndrome presented for surgical repair at 9 months of age, the ductus having remained open in the presence of a restrictive atrial septal defect. In addition, an anomalous left coronary artery originating from the right pulmonary artery was found. After preliminary blade/balloon atrial septostomy, a successful modified Norwood procedure with concomitant reimplantation of the anomalous coronary artery was performed.
Model-based simulation of the consolidation processing of metal coated fibers

Abstract The consolidation of metalized ceramic fibers by hot isostatic pressing (HIP) offers an attractive route for the manufacture of continuous fiber reinforced titanium matrix composites (TMCs). The performance of this class of composites is controlled by the fiber/matrix properties and by the composite's relative density, the grain size of the matrix alloy and the interfacial reaction layer thickness at the fiber–matrix interface after processing. Recently developed process models that predict the evolution of these microstructural attributes during consolidation processing are summarized and combined with consolidation equipment dynamics to simulate the microstructural evolution of PVD Ti–6Al–4V coated Sigma 1240 (SiC) monofilaments during HIP. For this system, diffusion accommodated grain sliding is the dominant densification mechanism for process cycles that preserve the refined grain size of the PVD metal coating.
Hydrogeochemical Evaluation of the Quaternary Aquifer in El Sadat City, Egypt

Land reclamation projects and construction of new cities represent one of the Egypt’s strategic polices to meet the over increasing population. The Quaternary aquifer represents the main water bearing formation in the study area, which extends from the Rosetta branch in the east to Wadi El-Natrun in the west and from south El-Khattab road at south to El-Nubaria and El-Nasser canals in the north. The present hydrogeological conditions of this area are studied to understand the stresses imposed by these reclamation projects and extensive use of groundwater on heads and quality. The hydraulic head map shows that the aquifer is recharged from the Nile Delta in the east. The present work throws light on the hydrochemistry of the Quaternary aquifer facies in El Sadat City and determines geochemical type, origin, evolution of groundwater and their relation to the prevailing hydrogeological and environmental conditions, and finally evaluates the suitability of ground water for different uses.