cssi/SciSciGPT-SciSciNet huggingface dataset:
Levofloxacin-Induced Acute Hyperpigmentation Changes in a Chronic Kidney Disease Patient

Medication-induced cutaneous hyperpigmentation has variable clinical presentations and is dependent on the specific drug involved. Most commonly, an attentive patient observes such changes early in the course; when missed by the patient, such changes are usually noted by an observant clinician. Clinical diagnosis can be challenging if the patient is on multiple medications because other causes must be excluded. This condition occurs via multiple mechanisms. Frequently, the pigmentary change is reversible with discontinuation of the drug. Causative medications include nonsteroidal; anti-inflammatory agents, antimalarials, antibiotics, psychotropics, amiodarone, and chemotherapeutic agents. The; antimicrobials responsible for hyperpigmentation are antimalarials, tetracyclines, tigecycline, dapsone, rifampicin, and antiretrovirals such as zidovudine. Sunlight exposure can worsen the pigmentation seen with some of the above antimicrobials (e.g., dapsone). Here, we describe an older adult white woman presenting with acute cutaneous; hyperpigmentation of the bilateral lower extremities while on levofloxacin therapy. Hyperpigmentation resolved after cessation of the agent. Our case highlights this unique acute presentation after only a few days of oral levofloxacin.
Longitudinal changes in network homogeneity in presymptomatic C9orf72 mutation carriers

The risk for carriers of repeat expansion mutations in C9orf72 to develop amyotrophic lateral sclerosis and frontotemporal dementia increases with age. Functional magnetic resonance imaging studies have shown reduced connectivity in symptomatic carriers, but it is not known whether connectivity declines throughout life as an acceleration of the normal aging pattern. In this study, we examined intra-network homogeneity (NeHo) in 5 functional networks in 15 presymptomatic C9+ carriers over an 18-month period and compared to repeated scans in 34 healthy controls and 27 symptomatic C9+ carriers. The longitudinal trajectory of NeHo in the somatomotor, dorsal attention, and default mode networks in presymptomatic carriers differed from aging controls and symptomatic carriers. In somatomotor networks, NeHo increased over time in regions adjacent to regions where symptomatic carriers had reduced NeHo. In the default network, the posterior cingulate exhibited age-dependent increases in NeHo. These findings are evidence against the proposal that the decline in functional connectivity seen in symptomatic carriers represents a lifelong acceleration of the healthy aging process.
Facial Gunshot Wound: Mandibular Fracture With Internal Fixation and a Pectoralis Myocutaneous Flap Coverage.

Facial penetrating gunshot wounds (GSWs) are seen in an assault, suicide, and accidental injury. They often carry high mortality given the important anatomical structures located within the neck. The foundations of maxillofacial GSWs are rooted in data from military combat, specifically the last world war. This type of injury is complex for reconstructive surgery due to significant soft tissue and bone loss. Management of maxillofacial GSWs is often challenging and has trended from serial debridement, immediate reconstruction, local tissue flaps, and distant free flap transfers depending on bullet trajectory and wound intricacy. We present a case of a 51-year-old male with a 22-caliber GSW to the left side of his face. Hemodynamics were stable on arrival and history included alcohol use. A left mandibular wound measured approximately 8 cm in diameter with exposed bone. A small 0.5-1 cm wound was also present inferiorly. A maxillofacial CT scan was utilized, showing a left mandibular body fracture. The patient underwent exploration and debridement on the same day of injury. Open reduction with internal fixation of the left mandible fracture and Synthes 2.5 mm locking plate was done. Additionally, a left pectoralis major myocutaneous muscle flap was performed two days later. Regional pectoralis flap reconstruction of facial firearm injury is scarcely acknowledged in the literature. Due to the location of the wound, the functionality of the jaw can be maintained in addition to ample blood supply by performing mandibular fixation and pectoralis major myocutaneous flap.
Exploring PIM Architecture for High-Performance Graph Pattern Mining

Graph mining applications, such as subgraph pattern matching and mining, are widely used in real-world domains such as bioinformatics, social network analysis, and computer vision. Such applications are considered as a new class of data-intensive applications that generate massive irregular computation workloads and memory accesses, which are different from many well-studied graph applications such as BFS and page rank. In this letter, we use the emerging process-in-memory architecture to accelerate data-intensive operations in graph mining tasks. We first identify the code blocks that are best suitable for PIM execution. Then, we observe a significant load imbalance on PIM architecture and analyze the root cause for such imbalance in graph mining applications. Lastly, we evaluate several scheduling schemes that help reduce the load imbalance and discuss potential optimizations to enhance performance further.
Moving Beyond Equal Access: Detracking a High School’s Mathematics Program

Students of color in the United States have historically been denied access to a college-preparatory mathematics education largely due to tracking policies and practices. To address this historical injustice, a partnership was developed between a highly diverse high school and higher education to initiate a collaborative process to detrack the mathematics program at the school. We report the results from empathy interviews conducted with the “Franklin High” administrative team and mathematics teachers. The four primary themes that emerged from the interviews concerned the school’s student diversity, the focus on preparing students to enter the IB course sequence, how detracking must go beyond simply providing equal access, and the importance of the Franklin High staff having an equity-oriented growth mindset. These findings accentuate how successful detracking efforts require stakeholders to have an historical understanding of the racist policies and practices that have led to segregated schools and tracked classrooms.
Risk Factors for Venous Thromboembolism after Vascular Surgery and Implications for Chemoprophylaxis Strategies.

Abstract Objective Venous thromboembolism (VTE) is an important cause of postoperative morbidity and mortality, but the reported incidence after major vascular surgery ranges from as low as 1% to upwards of 10%. Further, little is known about optimal chemoprophylaxis regimens or rates of post-discharge VTE in this population. This study aimed to better characterize in-hospital and post-discharge VTE after major vascular surgery, the role of chemoprophylaxis timing, and the association of VTE with mortality. Methods A single center retrospective study of 1,449 major vascular operations (2013-2020) was performed, and included 189 EVARs (13%), 169 TEVARs (12%), 318 open aortic operations (22%), 640 lower extremity bypasses (44%), and 133 femoral endarterectomies (9%). Baseline characteristics, anticoagulant/antiplatelet medications, and outcomes were abstracted from an electronic data warehouse with medical chart auditing. Post-operative VTE (pulmonary embolism [PE] and deep vein thrombosis [DVT]) within 90-days of surgery was classified based on location, symptoms, and treatment. Cut point analysis using Youden’s index identified the most VTE discriminating timing of chemoprophylaxis (including therapeutic/prophylactic anticoagulant and antiplatelet medications) and Caprini score. Multivariable logistic regression tested the association of VTE with chemoprophylaxis timing, Caprini score, and additional risk factors. Cox proportional hazard modeling measured the association between VTE and mortality. Results Overall VTE incidence was 3.4% (65% DVTs, 25% PEs, 10% both) and 37% were post-discharge. The rate of symptomatic VTE was 2.4%, which was lowest for EVAR (0.0%) and highest for open aortic operations (4.1%, p=0.02). Individuals who developed VTE had longer length of stay, higher rates of end-stage renal disease, prior VTE, and higher Caprini scores (8 vs 5 points) (all p > 2 units of blood postoperatively, have an unplanned return to the operating room, have delayed chemoprophylaxis/anticoagulation/antiplatelet initiation >4 days postoperatively, and had increased 90-day mortality (all p > 7 (29% of patients) was associated with post-discharge VTE (2.6% vs 0.7%, p=0.01), and chemoprophylaxis/anticoagulation/antiplatelet timing >4 days was associated with increased adjusted odds of VTE (odds ratio 2.4 [1.1-4.9]). Although no fatal VTEs were identified, VTE was an independent predictor of 90-day mortality (adjusted hazard ratio 2.7 [1.3-5.9]). Conclusions These data highlight that patients undergoing major vascular surgery are particularly prone to VTE with frequent hypercoagulable comorbidities and earlier initiation of chemoprophylaxis is associated with reduced risk of development of VTE. Furthermore, post-discharge VTE rates may reach thresholds warranting post-discharge chemoprophylaxis, particularly for patients with Caprini scores > 7.
Characterization and aggressiveness of take-all root rot pathogens isolated from symptomatic bermudagrass putting greens

Take-all root rot is a disease of ultradwarf bermudagrass putting greens caused by Gaeumannomyces graminis (Gg), Gaeumannomyces sp. (Gx), Gaeumannomyces graminicola (Ggram), Candidacolonium cynodon...
XXVI. The absence of ionization by electrons with speeds comparable with that of light

(1924). XXVI. The absence of ionization by electrons with speeds comparable with that of light. The London, Edinburgh, and Dublin Philosophical Magazine and Journal of Science: Vol. 47, No. 278, pp. 306-319.
Chapter 12 The Use of Incubated Retinas in Investigating the Effects of Calcium and Other Ions on Cyclic-Nucleotide Levels in Photoreceptors

Publisher Summary This chapter discusses the use of incubated retinas in investigating the effects of calcium and other ions on cyclic-nucleotide levels in photoreceptors. Photoreceptors contain both cyclic adenosine 3´,5´-monophosphate (cAMP) and cyclic guanosine 3´,5´-monophosphate (cGMP). The chapter discusses the hypothesis that explains the effect of calcium chelation on cGMP levels, which is the disinhibition of the guanylate cyclase of the outer segment. The calcium chelation that increases cGMP is, thus, far unique to the retina among nervous tissues. In addition to the particulate Ca 2+ -inhibitable guanylate cyclase of the outer segment, the ground squirrel retina may have a soluble Ca 2+ -activated guanylate cyclase in its cone inner segments. At present, there is no evidence that photoreceptors are postsynaptic to any cell using a chemical transmitter that activates adenylate cyclase in postsynaptic membranes. However, cAMP might be associated with glycogen metabolism, microtubule assembly, the modulation of protein synthesis, or photovoltage-controlled activities.
Physics of accretion disks with magnetic flares

Rapid progress in multi-wavelength observations of Seyfert Galaxies in recent years is providing evidence that X-ray emission in these objects may be produced by magnetic flares occurring above a cold accretion disk. Here we attempt to develop a physically consistent model of accretion disks producing radiation via magnetic flares as well as the optically thick intrinsic disk emission. We place a special emphasis on comparison of the theory and the observations of Active Galactic Nuclei (AGN) and Galactic Black Hole Candidates (GBHCs). In particular, theoretical issues considered in this work provide tentative explanations for: (1) the origin of the Big Blue Bump of Seyfert 1 Galaxies. (2) the recently discovered X-ray Baldwin effect and the controversy over the existence of BBBs in quasars more luminous than typical Seyferts. (3) The differences and similarities in X-ray spectra of Galactic Black Hole Candidates and Seyfert 1s. (4) The hard/soft state transitions of GBHCs and AGN. Our conclusion is that the agreement between the theory and observations is very encouraging and we thus suggest that the physics of magnetic flares is the physics that should be added to the standard accretion disk theory in order to produce a more realistic description of radiation from accretion flows with a large angular momentum.
Effect of HIV/AIDS and Malaria on the Context for Introduction of Zinc Treatment and Low-osmolarity ORS for Childhood Diarrhoea

Diarrhoea was estimated to account for 18% of the estimated 10.6 million deaths of children aged less than five years annually in 2003. Two—Africa and South-East Asia—of the six regions of the World Health Organization accounted for approximately 40% and 31% of these deaths respectively, or almost three-quarters of the global annual deaths of children aged less than five years attributable to diarrhoea. Much of the effort to roll out low-osmolarity oral rehydration solution (ORS) and supplementation of zinc for the management of diarrhoea accordingly is being devoted to sub-Saharan Africa and to South and South-East Asia. A number of significant differences exist in diarrhoea-treatment behaviours and challenges of the public-health systems between Africa and Asia. The differences in rates of ORS use are the most common indicator of treatment of diarrhoea and vary dramatically by and within region and may significantly influence the roll-out strategy for zinc and low-osmolarity ORS. The prevalence of HIV/AIDS and the endemi-city of malaria also differ greatly between regions; both the diseases consume the attention and financial commitment of public-health programmes in regions where rates are high. This paper examined how these differences could affect the context for the introduction of zinc and low-osmolarity ORS at various levels, including the process of policy dialogue with local decision-makers, questions to be addressed in formative research, implementation approaches, and strategies for behaviour-change communication and training of health workers.
Emigración y compromiso político en México

Este articulo constituye un esfuerzo por comprender si hay una relacion entre la migracion y el compromiso politico entre aquellos que se quedaron en Mexico. Utilizamos los datos de la encuesta cide-cses 2006 que complementamos con datos de otra encuesta nacional para analizar la relacion entre las diversas manifestaciones de la migracion y varios indicadores de compromiso politico en Mexico. En particular, identificamos los siguientes canales a traves de los cuales la migracion puede influir en el compromiso politico en Mexico: si el entrevistado tiene parientes cercanos en Estados Unidos, si recibe remesas, si tiene planeado mudarse a Estados Unidos o si alguna vez ha trabajado en ese pais. Posteriormente modelamos varios indicadores de involucramiento politico en Mexico (por ejemplo, niveles de informacion politica, frecuencia de conversaciones sobre politica dentro y fuera de los hogares y participacion electoral) como funcion de dichas manifestaciones de la migracion y variables de control pertinentes. Nuestros hallazgos muestran que, en contra del conocimiento convencional (que sugiere que la migracion y en particular las remesas, debido a su magnitud, ayudaran a resolver los retos de desarrollo a los que se enfrenta Mexico), la migracion puede, de hecho, deprimir el compromiso politico en Mexico.
Differentiating Bullish From Bearish Factors In The Arbitrage Pricing Theory

This is a teaching note on a proposed approach that will correct a common flaw in the way the return-generating process within the APT framework is illustrated in textbooks. The problem can be resolved by dichotomizing the risk factors into two kinds. Based on this approach, the author eliminated the main source of confusion and developed an alternative way to teaching this important financial theory in a comprehensive and intuitive manner.
High strain rate effects on the structure of a simulated silica glass

Abstract The structure of an SiO2 glass was simulated using am odified Born-Meyer-Huggins pair potential. Molecular dynamics calculations of the response of the low temperature glass to an applied rate of deformation exhibited brittle fracture. At strain rates slow enough to allow atomic thermal vibrations to occur, the strength of the glass is decreased by 60%. The strain rate dependence of fracture and the effect of internal cracks are examined.
Fluconazole in the treatment of systemic candidiasis: an open-label, noncomparative, multinational study

The incidence of opportunistic fungal infections has been increasing in recent years. Fluconazole has demonstrated significant clinical potential and is an attractive alternative to amphotericin B for the treatment of these infections. The present study investigated the efficacy and safety of fluconazole (100 to 400 mg/d) in severely ill patients with microbiologically documented systemic candidiasis. Of the 51 patients enrolled, 39 were assessable for efficacy. The predominant pathogen isolated was Candida albicans. At the end of treatment, clinical and mycologic response was 100%. At follow-up, one patient experienced a relapse caused by C albicans. The most common drug-related adverse events involved the gastrointestinal system (eg, diarrhea and vomiting); no patients withdrew from the study because of adverse events. Thus fluconazole appeared to be effective and safe in the treatment of systemic candidiasis.
Force-Deflection Spectroscopy: A New Method to Determine the Young's Modulus of Nanofilaments

We demonstrate the determination of Young's modulus of nanowires or nanotubes via a new approach, that is, force-deflection spectroscopy (FDS). An atomic force microscope is used to measure force versus deflection (F-D) curves of nanofilaments that bridge a trench patterned in a Si substrate. The FD data are then fit to the Euler-Bernoulli equation to determine Young's modulus. Our approach provides a generic platform from which to study the mechanical and piezoelectric properties of a variety of materials at the nanoscale level. Young's modulus measurements on ZnS (wurtzite) nanowires are presented to demonstrate this technique. We find that the Young's modulus for rectangular cross section ZnS nanobelts is 52 +/- 7.0 GPa, about 30% smaller than that reported for the bulk.
Directed network reliability: Domination and computing coefficients of the success-marginal expansion

The reliability for communication in a directed network can be expressed as a summation of terms, each of which involves a success-marginal probability, that is, the probability of an event of the form {the arcs in set S are working}. Satyanarayana and Prabhakar introduced the concept of domination in order to characterize the coefficients of one such expression. This paper observes that domination can be interpreted as a partial derivative of the reliability multinomial and extends results derived for domination to the general class of expressions involving success-marginal probabilities.
Maternal and fetal β-endorphin release in response to the stress of labor and delivery

In order to clarify the stress effect of labor on maternal and neonatal plasma levels of β-endorphin, we measured this peptide in samples taken from 40 pregnant patients and their neonates at the time of normal vaginal delivery (n = 15), and at cesarean section performed either in early labor (n = 13) or prior to labor (n = 12). The mean (± SE) maternal plasma concentration of β-endorphin in the vaginal delivery group was 40.3 ± 5.6 fmol/ml, which was significantly higher than that in their neonates (21.3 ± 2.9 fmol/ml). In contrast, maternal levels of β-endorphin in the cesarean section groups (8.2 ± 1.2 and 8.5 ± fmol/ml) were significantly lower than those in their neonates (23.3 ± 5.6 and 15.6 ± 2.8 fmol/ml). Concentrations of β-endorphin in mothers delivered vaginally were also significantly higher than those in mothers delivered by cesarean section. However, there was no difference in mean cord levels of β-endorphin among the three groups. These findings indicate that (1) neither the presence or absence of labor affects fetal plasma β-endorphin secretion and (2) the stress of labor and delivery produces a marked increase in maternal release of β-endorphin.
The Effect of Methods of Cutting and Grinding on Sensitization in Surface Layers on AISI 304 Stainless Steel

Abstract Various water cooled cutting and grinding operations were found to promote sensitization to intergranular attack of AISI 304 stainless steel in two ways. There may be precipitation of chromium carbides, one to two grains deep, at grain boundaries near the surface, even during water cooled cutting with an abrasive wheel. Of greater importance is the sensitization observed when cut material is heated at relatively low temperatures, 300 or 500 C for 24 h to 19 days. The resulting sensitized surface layer is up to seven grains (0.5 mm) deep in a steel containing 0.069% C, without any effect at these temperatures on the bulk material below this layer. In both types of sensitization, stress appears to be a powerful promoter of carbide precipitation. During cutting with a water cooled abrasive wheel, the stress applied by the wheel accelerates carbide precipitation in a thin layer during very brief exposures at the relatively high temperatures generated by the cutting action. During prolonged isothermal...
Evaluation of photodynamic therapy efficiency using an in vitro three-dimensional microfluidic breast cancer tissue model

In recognition of the limitations of monolayer cell cultures and resource-intensive animal studies, a microfluidic culture system was developed for creation of physiologically relevant three-dimensional (3D) tissues. In this study, an in vitro 3D breast cancer tissue model was established in a microfluidic system with human breast cancer cells (MCF-7) and primary adipose-derived stromal cells (ASCs). It was evaluated for utility in determining the efficiency of photodynamic therapy (PDT) with therapeutic agents (i.e. photosensitizer and gold nanoparticles) under various irradiation conditions. We demonstrated, for the first time, the potential use of a microfluidic-based in vitro 3D breast cancer model for effective evaluation of PDT, with the capability of controlling 3D microenvironments for breast cancer tissue formation, real-time monitoring of tissue progression, implementing a circulation-like dynamic medium flow and drug supplements, and investigating the relation between light penetration and tissue depth in PDT.
Probing Interfaces and Surface Reactions of Zirconium Phosphate/Phosphonate Multilayers Using 31P NMR Spectrometry

We report our 31P magic angle spinning (MAS) NMR characterization of zirconium phosphate/phosphonate (ZP) multilayer assemblies grown on SiOx. The reaction of silica with excess POCl3 and treatment with collidine results in both physisorbed and chemisorbed HxPO4(x-3) being present at the SiOx surface. The 31P NMR spectrum of zirconium phosphate grown from silica shows no residual Cl-containing species, indicating essentially complete hydrolysis. The phosphate 31P resonances are broadened substantially upon complexation with Zr4+, and T1 data demonstrate the broadening to be inhomogeneous in nature. Data on maleimide−vinyl ether copolymer layers we reported recently [Langmuir 1999, 15, 1418] confirm that hydrolysis/deprotection by bromotrimethylsilane is efficient in converting phosphoesters to the corresponding phosphorus oxyacid in the synthesis of multilayers. Comparison of polymer multilayers with the relatively more ordered bisphosphonic acid-based multilayers indicates that essentially the same inter...
Caution in the use of Niskin bottles for hydrocarbon samples

Abstract Niskin bottles may release into a water sample hydrocarbons that have a distribution very similar to a petroleum product.
Predator Recognition and Learned Irrelevance in the Crayfish Orconectes virilis

When individuals of the crayfish Orconectes virilis detect an unlearned danger cue (alarm odor) and a novel cue (goldfish odor) at the same time, they form a learned association and behave as if the novel cue is associated with increased predation risk (Hazlett et al. 2002). This study examined the potential for learned irrelevance in O. virilis and the circumstances under which blockage of the formation of a learned association could occur. If individuals experience a random pattern of alarm odor and goldfish odor over the days prior to the simultaneous detection of those two cues, no learned association is formed (= learned irrelevance). That is, there is no inhibition of responses to a food cue when goldfish odor is added if the crayfish has experienced a random pattern of the two cues. Learning was eliminated if the random pattern of cues was experienced before or after the simultaneous detection. To present the two cues (alarm and goldfish odors) to crayfish independently on separate days, the water containing goldfish odor had to be removed from the aquaria as the odor persisted at least 24 h. The importance of the learned irrelevance phenomenon on predator-prey interactions is discussed.
Low-power side-channel attack-resistant asynchronous S-box design for AES cryptosystems

In this work, a novel asynchronous combinational S-Box (substitution box) design for AES (Advanced Encryption Standard) cryptosystems is proposed and validated. The S-Box is considered as the most critical component in AES crypto-circuits since it consumes the most power and leaks the most information against side-channel attacks. The proposed design is based on a delay-insensitive logic paradigm known as Null Convention Logic (NCL). The proposed NCL S-Box provides considerable benefits over existing designs since it consumes less power therefore suitable for energy-constrained mobile crypto-applications. It also emits less noise and has flatter power peaks therefore leaks less information against side-channel attacks such as differential power/noise analysis. Functional verification, analog simulation and power measurement of NCL S-Box have been done using Mentor Graphics EDA (Electronic Design Automation) tools to assure low-power side-channel attack-resistant operation of the proposed clock-free AES S-Box design.
Postretention evaluation of stability and relapse—Mandibular arches with generalized spacing

Assessment of cases that had been out of retention a minimum of 10 years and had displayed generalized spacing of anterior teeth before treatment showed consistent reduction of arch length and intercanine width into adult years. Intercanine width constriction typically occurred while arch length decreased in every case, both width and length reduction being progressive with time. Crowding was minimal for the majority of cases; few demonstrated the severe crowding more typical of cases with pretreatment crowding.
Accurate Detection Of Left Atrial Thrombus Prior To Atrial Fibrillation Ablation In Patients With Therapeutic Anticoagulation: Does Transesophageal Echocardiography Beat Conventional Wisdom?

risk of left atrial (LA) thrombus and systemic thromboembolism.1-4 Screening transesophageal echo (TEE) to rule out left atrial thrombus has become standard of care over the years.5 Conventional thinking of therapeutic anticoagulation for 4-6 weeks prior to cardioversion may not reduce the risk of left atrial thrombus completely. Left atrial thrombi can be seen on 2-9% of screening TEEs in AF patients with various levels of anticoagulation.5 Radiofrequency ablation of atria with pulmonary vein isolation (PVI) with or without various additional ablative techniques has evolved into very important strategy in the treatment of patients with AF.6-10 Even though the relative risk of systemic thromboembolism after non TEE guided cardioversion after 3 weeks of anticoagulation remains lower (approximately 0.8%) despite 7% prevalence of LA thrombi, the same may not be applicable to invasive treatment modalities like AF ablation.6, 11-13 The presence of LA thrombi may increase the risk of clot dislodgment and subsequent thromboembolism with catheter manipulation during AF ablation and is considered to be an absolute contraindication. In this issue of JAFIB, de Bono et al try to assess the risk of LA thrombi prior to AF ablation.14 It was a retrospective study that looked at 244 preprocedural TEEs in 148 consecutive patients who underwent AF ablation at their institution. After therapeutic INRs for 4weeks and warfarin holding 3 days prior the ablation, 4 out of the 244 screening TEEs showed LAA thrombus at 1.6%.
A tidal theory for the origin of the solar nebula

A model for the origin of the solar nebula is developed with attention to the significance of angular momentum considerations. Evidence that stars are born in groups rather than singly is examined. It is shown that protostars which are members of typical galactic clusters have some probability of undergoing a gravitational encounter with another star while they are collapsing. According to the model, these encounters impart disproportionate amounts of angular momentum to the later material to fall in toward already centrally condensed fragments. The amount of central condensation of a fragment is the overriding factor in determining its stability against destruction by tidal forces. The encounter also imparts angular momentum to matter that is still accreting onto the protosun.
Photoacoustic Spectroscopy and the In-Situ Characterization of the Electrochemical Interface

Photoacoustics is a new spectroscopic method which has been used for in situ characterization of the electrochemical interface during the past ten years. The basic principles of the photoacoustic effect and the principal results of the Rosencwaig-Gersho theory are discussed in light of the usefulness of the method in electrochemical studies. Different experimental arrangements suitable for in situ electrode studies are presented. A review of the use to date of photoacoustics in electrochemistry includes studies of electrochromic systems, semiconductor electrodes, passivation layers, and of electrocatalytic mixed oxides. These works demonstrated that, with relatively simple apparatus, it was possible to detect and to characterize very thin layers formed on electrodes. It is still not clear whether in most cases photoacoustic spectroscopy has an overwhelming advantage over well-established optical methods for absorption measurements; however, all the potentialities of the method have yet to be explored.
The use of symbolic convergence theory in corporate strategic planning: A case study

Abstract This case study reports on the employment of Symbolic Convergence Theory (SCT) to intervene in a corporate environment in a strategic planning situation. The study concerns the use of SCT to guide corporate positioning, market segmentation, and advertising and sales message testing. The report sets out SCT's assumptions and technical terms, summarizes the relevant research undergirding the SCT theory‐method‐message complex, describes the strategic planning intervention, illustrates the research findings, and draws out both the applied and theoretical implications of the case.
Variations in the distributions and isotopic composition of alkenones in Black Sea particles and sediments

Abstract Concentrations, unsaturation index (U37k) and isotopic compositions of individual alkenones were measured for samples of suspended particulate organic matter (POM), sediment trap and sedimentary organic matter from the Black Sea. In general, temperatures estimated from U37k are lower than actual sea surface temperatures, indicating existing calibrations may not be appropriate for alkenones in the Black Sea. Specifically, there is a lack of agreement among U37k values calculated with and without the concentration of the C37:4 alkenone which lead to significant differences in temperatures estimated using the available calibrations. The more unsaturated alkenones in suspended POM with high water column residence times may be degraded preferentially, resulting in the observed increase with depth of U37k values. The σ13C of individual alkenones in suspended particles decrease with increased unsaturation. However, there is no correlation between temperature inferred from U37k and the isotopic composition of individual alkenones. Isotopic compositions of the C37:4 alkenone are apparently independent of more saturated isomers. Although the overall pattern of the σ13C of higher molecular weight alkenones (C38, C39) with depth in the water column is similar to that of that of the di- and tri-unsaturated C37 alkenones, isotopic compositions of individual isomers range several permil. Variation in the isotopic compositions of alkenones may be due to differences either in the biological sources for or mechanisms for removal of alkenones in organic matter suspended in the waters of the Black Sea.
Ten-year experience with preimplantation genetic diagnosis (PGD) at the New York University School of Medicine Fertility Center

We describe our experience of over 300 cycles of preimplantation genetic diagnosis (PGD) and report clinical pregnancy rates (35%–67%) that support using this technology to screen for genetic disorders and chromosomal abnormalities. In clinical practice for over ten years, PGD offers couples the earliest form of genetic screening and may help improve ongoing pregnancy rates in poor-prognosis patients.
Do Students Use and Understand Free-Body Diagrams?

Physics education literature recommends using multiple representations to help students understand concepts and solve problems. However, there is little research concerning why students use the representations and whether those who use them are more successful. This study addresses these questions using free-body diagrams (diagrammatic representations used in problems involving forces) as a type of representation. We conducted a two-year quantitative and qualitative study of students' use of free-body diagrams while solving physics problems. We found that when students are in a course that consistently emphasizes the use of free-body diagrams, the majority of them do use diagrams on their own to help solve exam problems even when they receive no credit for drawing the diagrams. We also found that students who draw diagrams correctly are significantly more successful in obtaining the right answer for the problem. Lastly, we interviewed students to uncover their reasons for using free-body diagrams. We found that high achieving students used the diagrams to help solve the problems and as a tool to evaluate their work while low achieving students only used representations as aids in the problem-solving process.
Fine structure and composition of coronal cementum in guinea-pig molars.

Guinea-pig molars consist, in part, of a cartilage-like form of coronal cementum located within the buccal and lingual developmental grooves, and a more conventional coronal cementum occurring as small “pearls” on the peripheral surface of the enamel. The ultrastructure of demineralized cementum “pearls” was characterized by a relatively dense network of typically banded collagen fibrils within a finely granular organic matrix. The cartilage-like cementum matrix consisted primarily of finely granular, spherical aggregates, approximately 1–3 μm dia, closely packed together, which contained occasional, poorly defined collagen fibrils. Mineralization of this matrix was closely associated with matrix vesicles in a pattern similar to that reported for other mineralized tissues. Numerous lacunae within the calcified matrix contained the cellular remains of trapped cementoblasts. Chemical analysis indicated that cartilage-like cementum is approximately 62 per cent mineralized and is, therefore, more mineralized than cartilage. The collagen content of this form of cementum was approximately 5.5 per cent of total dry weight or 14 per cent by weight of demineralized matrix, a value considerably below that for dentine, conventional cementum, bone or cartilage. The hexosamine content was considerably below that reported in cartilage, but in the same range as that reported for bone. The organic matrix appeared to include elevated levels of acidic proteins which normally account for a small fraction only of the matrix of other calcified tissues. The CaPi and Ca + MgPi ratios were similar to those reported for apatite in other mineralized tissues.
A Bayesian approach to finding groups in a food web

A food web describes the feeding links between species in a community. The species in many food webs are organized into groups of highly linked species that are weakly linked to species in other groups. A Bayesian approach to identifying such groups in an observed food web is described. This approach extends a previous non-Bayesian one that does not exploit information about the relatively high density of links within groups and relatively low density between groups. Under the new approach, this information is encoded through prior distributions for within- and between-group link densities. The approach is shown to work well on simulated food webs. Results are presented of the application of the method to the Coachella Valley desert food web.
Regulation of bidirectional melanosome transport by organelle bound MAP kinase.

Abstract Regulation of intracellular transport plays a role in a number of processes, including mitosis, determination of cell polarity, and neuronal growth. In Xenopus melanophores, transport of melanosomes toward the cell center is triggered by melatonin, whereas their dispersion throughout the cytoplasm is triggered by melanocyte-stimulating hormone (MSH), with both of these processes mediated by cAMP-dependent protein kinase A (PKA) activity [1, 2]. Recently, the ERK (extracellular signal-regulated kinase) pathway has been implicated in regulating organelle transport and signaling downstream of melatonin receptor [3, 4]. Here, we directly demonstrate that melanosome transport is regulated by ERK signaling. Inhibition of ERK signaling by the MEK (MAPK/ERK kinase) inhibitor U0126 blocks bidirectional melanosome transport along microtubules, and stimulation of ERK by constitutively active MEK1/2 stimulates transport. These effects are specific because perturbation of ERK signaling has no effect on the movement of lysosomes, organelles related to melanosomes [5]. Biochemical analysis demonstrates that MEK and ERK are present on melanosomes and transiently activated by melatonin. Furthermore, this activation correlates with an increase in melanosome transport. Finally, direct inhibition of PKA transiently activates ERK, demonstrating that ERK acts downstream of PKA. We propose that signaling of organelle bound ERK is a key pathway that regulates bidirectional, microtubule-based melanosome transport.
Ernährungsforschung an intakten Kühen mit Hilfe von Isotopen als Tracern

Zusammenfassung 1 Die biodiemische Forschung am intakten Tier ist von der Einfuhrung von Isotopen als Merksubstanzen ganz besonders gefordert worden. Die Verwendung von radio-aktiven Isotopen auf diesem Gebiet wird illustriert durch Beispiele aus der Tatigkeit einer Forschungsgemeinschafl an der Landwirtschaftlichen Abteilung und der Hoch-schule fur Veterinarwissenschaft an der Universitat von California in Davis. 2 Die Anwendung von Radiophosphor zur Messung des endogenen Phosphors im Kot der Kuhe und die Messung der Mobilitat der Phosphor- und Kalziumspeicher, letztere im Zusammenhang mit Milchfieber, werden erortert. 3 Intravenose Injektion von Karbonat mit Radiokohlenstoff in Milchkuhe, ver-bunden mit der Messung des Radiokohlenstoffs in der Atmungskohlensaure und in den Bestandteilen der Milch, hat gezeigt, das 2 % des injizierten Karbonatkohlen-stoffs in organischen Bestandteilen der Milch erschien und das 10% des Kohlenstoffs im Milchzucker aus dem Blutkohlensaurepool stammen. 4 Intravenose Injektion von mit Radiokohlenstoff markierten Fettsauren, von Formiat bis Kaproat, verbunden mit Messung des Radiokohlenstoffs in Atmungskohlensaure und Milchbestandteilen, gaben Auskunft daruber, wie rasch der Kohlen-stoff des Karboxyls und der α-Gruppe dieser Sauren in Atmungskohlensaure ausge-schieden wird und wieviel davon in Milchzucker, Milchfett und im Kasein erscheint. 5 Wir haben berechnet, wieviel der Kohlenstoffubertragung von Fettsauren an Milchbestandteile durch den Kohlensaurepool geht. 6 Unter den Fettsauren ubertrug nur Azetat mehr Kohlenstoff an Milchfett als an Milchzucker; insbesondere Butyrat verhielt sich glukogen. Die intramolekulare Verteilung des Radiokohlenstoffs in den Aminosauren des Kaseins spricht dafur, das Buttersaure als Azetyl in den Krebszyklus eingeht, aber nicht via Azetatpool. 7 Der Anteil des Euters gegenuber dem anderer Organe an der Kohlenstoffubertragung - und auch der Phosphorubertragung an Kasein - konnte an der intakten Kuh durch Injektion des Tracers in ein Euterviertel untersucht werden. 8 Vermutlich wird Buttersaure zur Hauptsache auserhalb des Euters, z. B. in der Leber, Essigsaure aber vornehmlich im Euter umgewandelt. 9 Die Rolle der Glukose als Kohlenstofflieferant fur Atmungskohlensaure und Milchzuckerbildung wird erortert im Zusammenhang mit Ketosis hochproduzierender Milchkuhe. 10 Wenn Norleuzin, eine fremde Aminosaure, ins Blut einer Kuh injiziert wurde, erschien ein erheblicher Teil ihres Kohlenstoffs in der Atmungskohlensaure und ein anderer, 27 %, in den organischen Bestandteilen der Milch. Ein Teil des Norleuzins wurde scheinbar als Norleuzin in das Kasein eingebaut.
BEM solution to transient free convective heat transfer in a viscous, electrically conducting, and heat generating fluid

The nonlinear partial differential equations for the transient free convective heat transfer in a viscous, electrically conducting, and heat-generating fluid past a vertical porous plate in the presence of free stream oscillations are solved by the boundary element method (BEM). Time-dependent fundamental solutions are employed in a time marching scheme to resolve the field variables. Numerical results are compared with previously reported analytical solutions in order to validate the developed BEM algorithm. These previous studies reported results for simpler versions of our problem, in which the convective effects in the momentum and energy equations were neglected in order to obtain analytical numerical solutions. Our BEM results are shown to be in close agreement with the reported data. The effects of convection currents, the temperature-dependent heat sources (or sinks), the magnetic currents, and the viscous dissipation on the flow and heat transfer characteristics are assessed in a parametric study...
Two classes give lessons about CCA.

In a world where nature has designed elegant template-dependent mechanisms for the reproduction of nucleic acid sequences, template-independent RNA polymerases have long been mysterious. Now, two papers provide structural insight into one of these template-independent systems—the addition of the sequence CCA onto the 3′ ends of transfer RNAs.
OrbitView: Eye movement visualization software

Measurement of eye movements often helps to diagnose ocular motor disorders in the clinic, and is also used as a research tool in ocular motor, vision and vestibular research. Eye movements, however, are usually recorded without simultaneous video recordings, making offline interpretation difficult. We developed a tool that converts the measured eye movement data into a three-dimensional (3D) movie of eye movements. Having useful functions such as slow-play, pause and exaggeration of the movements, this new software provides a research and teaching tool to aid interpretation of the recorded eye movements.
Crystal structure and conformation of methionyl dipeptides: Structure of L -methionyl- L -asparagine: Preferred conformations of peptides containing methionyl and asparaginyl residues

Crystals of L-methionyl-L-asparagines (C9N3H17O4S) are orthorhombic, space group P212121, with cell parameters at 294 K of a = 5.248(1), b = 13.251(2), c = 18.028(2) A, V = 1251.6(4) A3, Z = 4, Dm = 1.40 Mg/m3, and Dx = 1.397 Mg/m3. The crystal structure was solved by direct methods and refinded by full-matrix least-squares method to a final R value of 0.059 for 1804 reflections. The peptide is slightly nonpalnar [ω = 172.0(5)∘]; the other torsion angles ψ1, ϕ2, ψ21, and ψ22 are 155.6(5), −95.8(5), 152.5(5), and −29.4(6)∘ respectively. The methionyl side chain is disordered with two possible position for its Cγ, Sδ, and Ce atoms. The methionly side chain is twisted with χ1 = −86.4(7), χ2 = 177.5(9), and χ3 = 116.6(2)∘ for the major conformer A. The asparaginyl side chain is also twisted with χ1 = −76.3(5) and χ2 = 102.3(6)∘. The crystal structure is stabilized by an intermolecular network of hydrogen bonds involving the N-terminal amino group and the e-terminal amino group of asn residue as donors and the carboxyl oxygens of the C-terminal and the peptide carbonyl oxygens as acceptor atoms.
Brief communication: Better ways to question patients about adverse medical events: a randomized, controlled trial.

Background: There is no standard method of identifying adverse events in clinical trials. Objective: To determine whether 3 different methods of questioning patients about adverse events in a clinical trial affect the frequency of reported events. Design: Randomized, single-blind, controlled trial. Setting: A Veterans Administration medical center, San Francisco, California. Participants: Men 50 years of age or older who had benign prostatic hyperplasia. Measurement: Frequency of self-reported medical problems. Intervention: The authors randomly assigned 214 men who were undergoing a 1-month, single-blind, placebo run-in period during an existing clinical trial to 3 groups to test different self-administered methods of assessing medical problems at the end of the run-in period. The first group was asked an open-ended question; the second group was asked an open-ended, defined question; and the third group was given a checklist of 53 common side effects. Results: All 214 patients completed the study. Patients assigned to the checklist group reported a total of 238 adverse events; in comparison, patients who were asked an open-ended question or an open-ended, defined question reported 11 and 14 adverse events, respectively (P < 0.001). The percentage of patients reporting any adverse event was also much higher in the group assigned to the checklist (77%) than in the first group (14%) or second group (13%) (P< 0.001). Limitations: The study included only relatively healthy, well-educated, middle-aged men and assessed only self-reported medical problems after the participants had taken placebo for 1 month. All personnel overseeing the study were aware of the group assignments. Conclusions: Different methods of collecting patient data regarding adverse events lead to large differences in the reported rates of adverse events in clinical trials, potentially reducing the validity of comparisons between the side effect profiles of drugs and other interventions.