cssi/SciSciGPT-SciSciNet huggingface dataset:
How (Not) to Control for Population Size in Ecological Analyses

It is common for social scientists to use formal quantitative methods to compare ecological units such as towns, schools, or nations. In many cases, the size of these units in terms of the number o...
Self-help groups as platforms for development: The role of social capital.

Abstract Women-led self-help groups (SHGs) are increasingly being utilized as platforms for delivering development activities by funding agencies and governmental bodies. However, there is currently little understanding as to whether SHGs are effective or equitable platforms for delivering health or livelihoods interventions. Social capital is hypothesized as a comparative advantage when utilizing SHGs as development platforms, however the specific mechanisms have yet to be explored. This paper investigates the efficacy and equity of SHGs as platforms for development programs through analyzing 64 interviews and 6 focus group discussions collected from an agriculture and behavior change intervention delivered through SHGs in eastern India. We find that while, theoretically, SHGs are a promising platform for health messaging this is largely dependent on SHG norms of attendance, which itself is closely tied to socioeconomic conditions and social capital. Social capital is important both within SHGs as well as between SHGs and the implementing organization. Sites with more mature SHGs had greater economic security allowing more active participation in the intervention than sites with more poverty and young SHGs. The former sites also had greater norms of trust and reciprocity (social capital) with the implementing organization that led them to accept additional interventions. In the latter sites, SHG members had competing demands on their time and less trust in the implementers, making it difficult to attend both SHG meetings and health sessions. We put forth a materialist understanding of social capital formation, where SHG members must have already received substantive benefit from membership for new activities to be successfully incorporated into their agenda. Further, using SHGs as a nutrition message delivery platform should not detract from individual engagement with more vulnerable members of the community.
Application of the Database of Flavonoid Values for USDA Food Codes 2007–2010 in assessing intake differences between the Healthy Aging in Neighborhoods of Diversity across the Life Span (HANDLS) study and What We Eat in America (WWEIA), NHANES

Abstract Flavonoids are polyphenolic plant compounds whose biological activities may promote human health. It is worthwhile to examine whether flavonoid intake varies between populations with differing prevalence of diet-related diseases. This study compared flavonoid intakes in the Healthy Aging in Neighborhoods of Diversity across the Life Span (HANDLS) study with nationally representative estimates from What We Eat in America (WWEIA), NHANES stratified by sex, age (30−49, 50−64 years), and poverty status (income 125 % of the 2004 HHS Poverty Guidelines). Flavonoid intakes from both surveys were estimated using the Database of Flavonoid Values for USDA Food Codes 2007–2010. Across all subpopulations analyzed, intake of anthocyanidins was lower in HANDLS (p
Water as the part of landscape in nature based rural tourism, case Třeboň region

This article is aimed on attitudes of visitors of tourist rural area towards its ecotourism conditions, especially towards water as the part of its landscape. To compile the results of questionnaire survey analysis it can be said that the main recreational activities among Třeboň region’s visitors were biking and visiting of historical monuments. Only a few visitors were interested in nature-based activities (bird-watching, hunting). On the other hand quite high interest in recreational fishing was found. The most important part of Třeboň region’s image was water and the most important constituent of motivation was nature. There is a strong relation between the terms holiday and Třeboň region. The knowledge of Třeboň region’s nature was very poor and almost anyone had not participated in ecotourism activities. Only 15 % visitors were familiarised with the offer of ecotourism activities in the region.
Remote changes in the midbrain after hypoxic encephalopathy

An 11-month-old boy developed fever associated with influenza B infection, followed two days later by sudden cardiopulmonary arrest due to unknown etiology. Resuscitation was successfully performed and he was transferred to our hospital. After admission, intensive treatment was performed and he gradually recovered, however, he was left with severe neurological sequelae, such as spastic quadriplegia and severe mental retardation. Serial magnetic resonance imagings (MRI) during the course of illness are shown in Figs 1 and 2. Three days after admission, diffusion-weighted MRI disclosed lesions in the white matter areas of the bilateral centro-parietal and occipital lobes as well as putamen and claustrum with reduced diffusion (Fig. 1). Nine days after admission, diffusion-weighted MRI revealed lesions in the bilateral cerebral peduncles and globus pallidi with reduced diffusion (Fig. 2). These MRI findings may reflect serial changes of brain damage due to hypoxic encephalopathy. PeriRolandic and occipital regions are usually spared in children with hypoxic encephalopathy, and it remains unknown why this case showed peculiar distribution of the lesion in the initial phase. The lesion in the
Nash Equilibria for Weakest Target Security Games with Heterogeneous Agents

Motivated attackers cannot always be blocked or deterred. In the physical-world security context, examples include suicide bombers and sexual predators. In computer networks, zero-day exploits unpredictably threaten the information economy and end users. In this paper, we study the conflicting incentives of individuals to act in the light of such threats.
Protamine enhances epidermal growth factor (EGF)-stimulated mitogenesis by increasing cell surface EGF receptor number. Implications for existence of cryptic EGF receptors.

Abstract Treatment of Swiss mouse 3T3 cells and human epidermoid carcinoma A431 cells with protamine at 37 degrees C increased the 125I-epidermal growth factor (EGF) binding activity at 4 degrees C. The effect of protamine on the increase of 125I-EGF binding activity appeared to be time, temperature, and dose dependent. This up-modulation of 125I-EGF binding by protamine correlated with protamine enhancement of EGF-stimulated mitogenesis, with respect to the magnitude of the effect and the dose response curves. Scatchard plot analyses indicated that protamine induced an increase in numbers of both high and low affinity EGF receptors without affecting their affinities. Protamine also increased functionally active EGF receptors in plasma membranes and solubilized membranes. This was evidenced by Scatchard plot analyses and by a protamine-induced increase of 125I-EGF-EGF receptor complex and an increase in EGF-stimulated phosphorylation of the EGF receptor. Combined with column chromatography of the solubilized EGF receptor on protamine-agarose gel, these results suggest that protamine may increase the EGF receptor number by directly activating cryptic EGF receptors in the plasma membrane.
Main Effect Designs

In this article we consider experimental situations where a screening experiment is to be run and primary interest is in the identification of variables which have an influential effect on the process being studied. In such cases, main effects designs are often used. Main effects designs typically allow for the efficient estimation of main effects parameters and are particularly useful when the initial number of experimental variables being studied is large compared to the number of runs in the screening experiment. Here we describe a number of the orthogonal and nonorthogonal main effects designs available to practitioners along with some of their individual advantages and disadvantages. Keywords: orthogonal effects; factorial design; orthogonal array; nearly orthogonal array
Constructing numerical software libraries for HPCC environments

Summary form only given, as follows. Numerical software libraries have long been used in engineering and scientific computations on workstations and mainframes, but are just now becoming widely available on HPCC platforms. We describe recent developments in the SCALAPACK numerical linear algebra library, which have recently become available for currently existing massively parallel machines and networks of workstations. We outline SCALAPACK's functionality and current performance. We also describe efforts to ease technology transfers by providing 24-hour electronic access and online books of "templates" to help users find the best program to use. >
Posttraumatic growth in individuals with amputations.

Abstract Background Studying positive outcomes post-amputation is an important area of research in order to help individuals recover with the optimal quality of life possible. Objective To examine posttraumatic growth (PTG) in the understudied population of individuals with amputations. Our main aim was to assess the effect of gender, veteran status, age, and time since amputation on PTG. Our secondary aim was to examine the role support group participation on PTG. Methods Sixty-six adults with amputations completed an online survey consisting of the Posttraumatic Growth Inventory (PTGI) and free response questions about experiences with support groups. T-tests and correlations were the main statistical analyses. Results There were no gender differences in PTGI scores. Veterans had significantly lower PTGI scores than civilians, t(64) = 2.63, p Conclusions Veterans may be a specific population to target for PTG. Support groups appear to be a venue associated with higher levels of growth.
Patterns of search: analyzing and modeling Web query refinement

We discuss the construction of probabilistic models centering on temporal patterns of query refinement. Our analyses are derived from a large corpus of Web search queries extracted from server logs recorded by a popular Internet search service. We frame the modeling task in terms of pursuing an understanding of probabilistic relationships among temporal patterns of activity, informational goals, and classes of query refinement. We construct Bayesian networks that predict search behavior, with a focus on the progression of queries over time. We review a methodology for abstracting and tagging user queries. After presenting key statistics on query length, query frequency, and informational goals, we describe user models that capture the dynamics of query refinement.
Why are there so many small plants? Implications for species coexistence

Summary 1The prominently right-skewed distribution of species sizes has been the subject of a large literature in animal ecology, but has received comparatively little attention from plant ecologists. It is evident that not all explanations that have been offered for animals are directly applicable to plants. 2We suggest three hypotheses that require further study in the interpretation of size-dependent species richness in plants. 3These hypotheses are all based on mechanisms that have generated, for smaller plants, a greater historical opportunity for speciation: (i) large adult plant size confers significant adaptation primarily in habitat types that have been relatively uncommon in space, across evolutionary time; (ii) relatively small species are more widely differentiated from each other in the environmental qualities defining their niches, many of which are made possible by the mere presence of larger species residing in the same habitat; and (iii) compared with large species, smaller species generally have higher fecundity allocation, i.e. they can produce a greater number of offspring per unit plant size per unit time, which generally confers a higher premium under most circumstances of natural selection, thus generating a potentially greater number of descendant individuals, and derived species. 4We discuss the implications of these hypotheses in addressing an underlying paradox in plant competition/coexistence theory, i.e. that large adult size is assumed to be the principal trait that confers competitive ability yet, even in those habitat types where competition is assumed to reach the highest levels of intensity within vegetation, the vast majority of the resident species are, nevertheless, relatively small.
On rotations as special cases of unitary transformations with some applications to the theory of spin

Some problems in elementary geometry are approached from the point of view of linear algebra and generalized to the theory of linear spaces of finite or infinite dimensions having a positive definite binary product. The angle ω between two elements of the linear space is defined from the concept of length by means of the cosine-theorem. A rotation is then defined as a special case of a unitary transformation moving all elements the same angle ω, except that under certain circumstances, some elements may stay invariant. In the former case, one speaks of a rotation around an “external axis,” and in the latter case, of a rotation around an “internal axis” defined by the invariant elements. It is shown that the finite rotations U of both types may be expressed in the simple exponential form U = exp(iωm), where the “generator” m in the former case is an operator satisfying the relation m2 = 1, and in the latter case, m3 = m. The structure of the group of finite rotations in the former case is clarified in some detail. As an illustration of the theory, some applications to the three- and two-dimensional spaces as well as to the theory of spin are given. The coupling between the ordinary three-dimensional rotations and the spinor transformations is considered in somewhat greater detail.
The Concept of Loop Inductance

This chapter contains sections titled: Self Inductance of a Current Loop from Faraday's Law of Induction The Concept of Flux Linkages for Multiturn Loops Loop Inductance Using the Vector Magnetic Potential Neumann Integral for Self and Mutual Inductances between Current Loops Internal Inductance vs. External Inductance Use of Filamentary Currents and Current Redistribution Due to the Proximity Effect Energy Storage Method for Computing Loop Inductance Loop Inductance Matrix for Coupled Current Loops Loop Inductances of Printed Circuit Board Lands Summary of Methods for Computing Loop Inductance
Mind maps as active learning tools

Active learning has been described by Bonwell and Eison [2] as an instructional technique that engages students in meaningful learning activities such as dialog, debate, writing, and problem solving, as well as higher-order thinking, e.g., analysis, synthesis, evaluation. Utilization of active learning is one of Chickering and Gamson's "Seven Principles for Good Practice" [5] for undergraduate teaching. Prince [23] describes several forms of active learning---collaborative learning, cooperative learning, and problem-based learning---in his review of active learning techniques. His research found support for all forms of active learning examined. The authors are investigating other forms of active learning aimed at improving critical thinking, problem-solving, and collaboration skills but which also use visual learning/thinking methods.
Self‐Repairing Polymeric Materials

This article outlines the recent advances in the field of self-healing polymers. The first part focuses on the role of stimuli-responsive components that are capable of responding to external stimuli, followed by reversible covalent bond formation facilitating self-repair processes. Dynamic exchange reactions between reversible covalent bonds offer another opportunity for the development of self-healing polymers. These along with stable free radical-mediated reshuffle reactions and heterocyclic compounds offer the unique opportunity for the development of heterogeneous polymeric systems capable of self-healing. Integrity of supramolecular networks is achieved by the formation of noncovalent interactions typically accomplished by the presence of associative groups covalently attached to side chains or chain ends of the polymers. These interactions are discussed in the context of hydrogen bonds, metal coordination, ionic interactions, π–π stacking, and host–guest interactions. Several features make supramolecular chemistry particularly attractive when it comes to self-healing, which are reversibility and speed, directionality, and sensitivity. Driven by a potential opportunity to close a mechanical crack, the last part of this article outlines self-healing achieved using encapsulation methods, remote self-healing, and the role of shape-memory polymers in facilitating self-repairs. While there are many exciting challenges facing this field, there are a number of opportunities in design, synthesis, and engineering of stimuli-responsive polymeric systems and Mother Nature serves as a supplier of endless inspirations. Keywords: self-repairing polymers; stimuli-responsive materials
Abstract 3025: HER2/Stat3 signaling mediated radioresistance in U87 glioma cancer cells through suppressed apoptosis and enhanced glycolysis

Proceedings: AACR Annual Meeting 2014; April 5-9, 2014; San Diego, CA GBM is the most common and aggressive malignant primary brain tumor, and the prognosis for GBM patients remains poor. Radiotherapy continues to play a central role in the management of brain tumors. Even though the advances of radiotherapy strategies and techniques, frequent failure of radiotherapy made GBM a disease difficult to be treated. GBM cancer stem cells (CSCs) are reported to be responsible for resistance to chemo- and radiotherapy, and chemotherapy and radiotherapy resistant GBM CSCs have been isolated from GBM. However, the mechanisms of radioresistance of glioma cells are still elucidative. In this study, we investigated the role of HER2-Stat3 signaling pathway in radioresistance using human glioma cell line U87. We found that long-term therapeutic dose of fragmented irradiation induces repopulation of human glioma U87 cells with increased number of CD133+/HER2+ stem-like cells. FIR-surviving CD133+/HER2+ U87 cells have coactivation of HER2 and Stat3 and increased cell proliferation and invasion abilities. More importantly, we found that U87-FIR cells have lower level of mitochondria metabolism and ROS level, and higher mitochondrial membrane potential, while 5Gy single dose radiation induces increased mitochondria function. Furthermore, U87 cell injection derived xenograph tumor also has increased mitochondrial membrane potential and decreased mitochondria function after radiation. These results suggest that the radioresistance of GBM CSCs possibly due to the suppressed apoptosis and enhanced glycolysis mediated by HER2/STAT3 pathway. Citation Format: Lili Qin, Ming Fan, Jian Jian Li. HER2/Stat3 signaling mediated radioresistance in U87 glioma cancer cells through suppressed apoptosis and enhanced glycolysis. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 3025. doi:10.1158/1538-7445.AM2014-3025
Predicting the success of limited exploration for primary hyperparathyroidism using ultrasound, sestamibi, and intraoperative parathyroid hormone: analysis of 1158 cases.

Objective:The aim of this study was to determine the success of limited neck exploration (LE) for primary hyperparathyroidism (1° HPT).Methods:Between 1999 and 2007, 1407 patients with hyperparathyroidism underwent bilateral neck exploration (BE). Of these, 1158 patients with first-time sporadic 1°
Percutaneous coronary intervention in stable patients after acute myocardial infarction.

Reperfusion after acute ST-segment elevation myocardial infarction (AMI) remains the cornerstone of the initial therapy. Although reperfusion can be accomplished with either primary angioplasty or fibrinolytic therapy, clinical trial data reveal improved outcome with primary angioplasty. Furthermore, primary angioplasty with coronary stenting results in less repeat revascularization than balloon angioplasty. Despite the advantages of mechanical revascularization, primarily with stenting, the majority of patients presenting with AMI will receive pharmacological reperfusion. See p 1324 How then should patients with AMI who are initially treated medically subsequently be managed? Medical therapy with platelet inhibition, β-blockade, ACE inhibition, and lipid lowering can all be accomplished according to guidelines. However, what is the role of revascularization after the most acute period? In patients with recurrent ischemia or severe multivessel disease with left ventricular dysfunction, the role of revascularization is relatively clear. However, is there a place for routine percutaneous revascularization (percutaneous coronary intervention [PCI]) in stable, post-AMI patients with 1-vessel disease? To address this question, Zeymer et al1 randomized 300 patients with 1-vessel disease 1 to 6 weeks after AMI to angioplasty or medical therapy between 1994 and 1997. Fibrinolytic therapy was used in 180 patients (60%). All patients had significant stenosis or total occlusion (29%) of the infarct-related artery (IRA) and no or mild angina. All but 11 (7.4%) patients in the invasive arm underwent angioplasty, but only 17% received stents. One-year mortality was 0.7% with angioplasty versus 3.3% with medical therapy ( P =0.21), and freedom from death, MI, revascularization, or readmission for severe angina was 90% for angioplasty versus 82% for medical therapy ( P =0.066). At 56 months, mortality was 4.0% with angioplasty versus 11.2% with medical therapy ( P =0.058), and survival free of reinfarction or revascularization was 80% in the interventional group and 66% in the conservative group ( P =0.05). …
The baboon as a nonhuman primate model for the study of the genetics of obesity

Objective: At present, rodents represent the most common animal model for research in obesity and its comorbidities (e.g., type 2 diabetes and coronary heart disease), however, there are several physiological and developmental differences between rodents and humans reflective of their relatively ancient evolutionary divergence (approximately 65 to 75 million years ago). Therefore, we are currently developing the baboon as a nonhuman primate model for the study of the genetics of obesity. Research Methods and Procedures: At present, we are collecting extensive phenotypic data in a large pedigreed colony (N > 2000) of baboons housed at the Southwest Foundation for Biomedical Research in San Antonio, Texas. The long-term goal of this project is to identify genes influencing adiposity-related phenotypes and to test hypotheses regarding their pleiotropic effects on other phenotypes related to increased risk for a variety of common diseases (e.g., coronary heart disease and type 2 diabetes). Results: To date we have obtained various adipose-specific endocrine measures, adipose tissue biopsies, and estimates of body composition on a substantial portion of our pedigreed colony. The pattern of adipose tissue accumulation follows closely that seen in humans, and we have detected significant additive genetic heritabilities for these obesity-related phenotypes. Discussion: Given the physiological and developmental similarities between humans and baboons, along with the ability to collect data under well-controlled situations and the extensive pedigree data available in our colony, the baboon offers an extremely valuable nonhuman primate model for the study of obesity and its comorbidities.
Optimized imaging spectrometers for geostationary environmental satellite systems

The future of remote sensing includes a significant role for imaging spectrometers in operational environmental satellite systems. Optimizing an imaging spectrometer design for geostationary orbit requires detailed study and evaluation of available technology and design architectures versus performance requirements and possible resource limitations that are unique to geostationary orbit operation. This paper summarizes a trade study of two candidate geostationary imaging spectrometer architectures that is constrained by performance requirements, cost and technical risk factors.
Micro/meso scale fatigue damage accumulation monitoring using nonlinear acoustic vibro-modulation measurements

Monitoring the incipient damage at the earliest possible stage is essential for predicting structural performance and remaining life of structural components. Existing prognostic methodologies incorporate conventional SHM and NDE techniques responsive to cracks and delaminations resulted from the irreversible material fracture and disintegration at the macro-scale. There is an increasing need for technologies that could allow for monitoring material degradation at the micro/meso scale before the onset of the macro-scale fracture. In this contribution, we report results of the real-time monitoring of the material micro/meso scale degradation using the nonlinear acoustic vibro-modulation technique. The technique explores nonlinear acoustic interaction of high frequency ultrasound and low frequency structural vibration at the site of the incipient damage. The indicator of the damage severity, nonlinear acoustic damage index (DI), was measured in real time during the strain-controlled three-point bending fatigue test of aluminum and steel specimens. Nondestructively, degradation of the specimen was revealed through the increase in the DI, which correlated well with the respective decrease in the specimen's stiffness. Destructive SEM examination confirmed sensitivity of the DI to the incipient micro/meso scale damage and advocated for utilizing the vibro-modulation approach for assessment of material degradation before fracture.
GIST: a gestural interface for remote nonvisual spatial perception

Spatial perception is a challenging task for people who are blind due to the limited functionality and sensing range of hands. We present GIST, a wearable gestural interface that offers spatial perception functionality through the novel appropriation of the user's hands into versatile sensing rods. Using a wearable depth-sensing camera, GIST analyzes the visible physical space and allows blind users to access spatial information about this space using different hand gestures. By allowing blind users to directly explore the physical space using gestures, GIST allows for the closest mapping between augmented and physical reality, which facilitates spatial interaction. A user study with eight blind users evaluates GIST in its ability to help perform everyday tasks that rely on spatial perception, such as grabbing an object or interacting with a person. Results of our study may help develop new gesture based assistive applications.
Time–temperature dependent brittle fracture of viscoelastic solids

The Griffith formulation is used to study fracture behavior of poly(methyl methacrylate) (PMMA) as a function of strain rate and temperature over the range 4.4 × 10−5 ≤ e ≤ 4.4 × 10−2 in./in./sec and 25°C ≤ T ≤ Tg, Tg being the glass transition temperature. It is found that the transition from brittle to ductile failure occurs abruptly at a temperature Tf which is dependent on strain rate and is approximately the same as the glass transition temperature of the material. The Griffith brittle fracture criterion is found to apply below Tf for all strain rates. The brittle fracture behavior is shown to obey the time–temperature equivalence principle in the same way as the material's other viscoelastic properties, having the same shift function.
Flavour biogenesis. Partial purification and properties of a fatty acid hydroperoxide cleaving enzyme from fruits of cucumber

Abstract A membrane-bound enzyme, which catalyses the cleavage of fatty acid hydroperoxides to carbonyl fragments, has been partially purified from cucumber fruit. The isomeric 9- and 13-hydroperoxydienes (but not the hydroxydienes) derived from both linoleic and linolenic acids are cleaved by the enzyme but a mixture of 9- and 10-hydroperoxymonoenoic derivatives of oleic acid was not attacked. No evidence was obtained for free intermediates between fatty acid hydroperoxides and the cleavage products. Major volatile products were: cis-3-nonenal and hexanal (from 9- and 13-hydroperoxides of linoleic acid respectively) or cis-3,cis-6-nonadienal and cis-3-hexenal (from 9- and 13-hydroperoxides of linolenic acid). The increase in the ratio of cis-3- to trans-2-enal products with enzyme purification indicated that cis-3-enals are the immediate cleavage products and that the trans-2- forms are produced by subsequent isomerization.
The velocity of conduction in nerve fiber and its electric characteristics

The theory developed in this paper shows that the propagation of spike potential along a nerve fiber and the conduction of an electric wave along an inert inorganic conductor follow a common quantitative relationship. This result gives further support to the belief that propagation of excitation is an electrical process. The basic idea of the theory is derived from the consideration that velocity has, by its mathematical definition, a local meaning; conduction in a nerve is completely determined by the local characteristics of the latter, as well as those of the wave. The final formula derived does not make use of any other field of science beyond the fundamental principles of electricity. It gives the conduction velocity in terms of the electric characteristics of the fiber and of the duration of the spike potential. The formula is in agreement with the known dependence of the conduction velocity on various parameters characterizing the axon. The computed velocity agrees with the measured ones on the squid giant axon, crab nerve axon, frog muscle fiber and Nitella cell. The membrane inductance appears as a velocity controling agent which prevents also a possible distortion of the spike potential during conduction. The structural meaning of the electric characteristics of the axon membrane is discussed from the viewpoint of the diffusion theory. A formula for the velocity of spread of the electrotonus is also derived.
The “Shiva Hypothesis”: Impacts, Mass Extinctions, and the Galaxy

The “Shiva Hypothesis”, in which recurrent, cyclical mass extinctions of life on Earth result from impacts of comets or asteroids, provides a possible unification of important processes in astrophysics, planetary geology, and the history of life. Collisions with Earth-crossing asteroids and comets ≥ a few km in diameter are calculated to produce widespread environmental disasters (dust clouds, wildfires), and occur with the proper frequency to account for the record of five major mass extinctions (from ≥ 108 Mt TNT impacts) and ~ 20 minor mass extinctions (from 107-108 Mt impacts) recorded in the past 540 million years. Recent studies of a number of extinctions show evidence of severe environmental disturbances and mass mortality consistent with the expected after-effects (dust clouds, wildfires) of catastrophic impacts. At least six cases of features generally considered diagnostic of large impacts (e.g., large impact craters, layers with liigh platinum-group elements, shock-related minerals, and/or microtektites) are known at or close to extinction-event boundaries. Six additional cases of elevated iridium levels at or near extinction boundaries are of the amplitude that might be expected from collision of relatively low-Ir objects such as comets. The records of cratering and mass extinction show a correlation, and might be explained by a combination of periodic and stochastic impactors. The mass extinction record shows evidence for a periodic component of about 26 to 30 Myr, and an ~ 30 Myr periodic component has been detected in impact craters by some workers, with recent pulses of impacts in the last 2-3 million years, and at ~ 35, 65, and 95 million years ago. A cyclical astronomical pacemaker for such pulses of impacts may involve the motions of the Earth through the Milky Way Galaxy. As the Solar System revolves around the galactic center, it also oscillates up and down through the plane of the disk-shaped galaxy with a halfcycle ~ 30±3 Myr. This cycle should lead to quasi-periodic encounters with interstellar clouds, and periodic variations in the galactic tidal force with maxima at times of plane crossing. This “galactic carrousel” effect may provide a viable perturber of the Oort Cloud comets, producing periodic showers of comets in the inner Solar System. These impact pulses, along with stochastic impactors, may represent the major punctuations in earth history.
Virus-specific mechanisms of carcinogenesis in hepatitis C virus associated liver cancer

The development of hepatocellular carcinoma (HCC) in persons who are persistently infected with hepatitis C virus (HCV) is a growing problem worldwide. Current antiviral therapies are not effective in many patients with chronic hepatitis C, and a greater understanding of the factors leading to progression of HCC will be necessary to design novel approaches to prevention of HCV-associated HCC. The lack of a small animal model of chronic HCV infection has hampered understanding of these factors. As HCV is an RNA virus with little potential for integration of its genetic material into the host genome, the mechanisms underlying HCV promotion of cancer are likely to differ from other models of viral carcinogenesis. In patients persistently infected with HCV, chronic inflammation resulting from immune responses against infected hepatocytes is associated with progressive fibrosis and cirrhosis. Cirrhosis is an important risk factor for HCC independent of HCV infection, and a majority of HCV-associated HCC arises in the setting of cirrhosis. However, a significant minority arises in the absence of cirrhosis, indicating that cirrhosis is not a prerequisite for cancer. Other lines of evidence suggest that direct, virus-specific mechanisms may be involved. Transgenic mice expressing HCV proteins develop cancer in the absence of inflammation or immune recognition of the transgene. In vitro studies have revealed multiple interactions of HCV-encoded proteins with cell cycle regulators and tumor suppressor proteins, raising the possibility that HCV can disrupt control of cellular proliferation, or impair the cell's response to DNA damage. A combination of virus-specific, host genetic, environmental and immune-related factors are likely to determine the progression to HCC in patients who are chronically infected with HCV. Here, we summarize current knowledge of the virus-specific mechanisms that may contribute to HCV-associated HCC.
Cdt1 throws kinetochore-microtubule attachments for a loop

The Ndc80 complex links spindle microtubules to the kinetochore to ensure the proper segregation of chromosomes during mitosis. Analysis of the replication licensing factor Cdt1 during mitosis now reveals a cooperative role with the Ndc80 complex in establishing stable microtubule attachments to the spindle.
Induction of single-strand breaks plus alkali-labile bonds by N-nitrosoureas in rat tissues in vivo: ethylnitrosourea versus benzylnitrosourea.

Abstract Alkaline sucrose sedimentation procedures were used to quantitate the amount of single-strand breaks plus alkali-labile bonds (SSB + ALB) induced and repaired following a single intraperitoneal injection of the neurocarcinogen N-ethyl-N-nitrosourea (ENU) and its non-neurocarcinogenic analog N-benzyl-N-nitrosourea (BNU) in the brain, liver and kidney of female Sprague-Dawley rats. SSB + ALB were measured and used as an indicator of apurinic/apyrimidinic sites, phosphotriesters and in situ breaks. ENU induced a dose-dependent increase in the number of SSB + ALB at the dose studied (0, 0.39, 0.77, 1.54 mmoles/kg) in all 3 tissues. At 1 h postinjection with 0.77 mmoles/kg of these compounds there were 50–70% fewer breaks induced by BNU than ENU. The SSB + ALB induced by ENU persisted over a 7-day period, while those induced by BNU did not. Thus, these studies showed that 2 homologues of nitrosoureas, ENU and BNU, exhibited different potentials to induce and to persist SSB + ALB in vivo.
Complex Yukawa potentials

Abstract An investigation is made of a variant of the Yukawa potential for which the scattering amplitude may have no more analyticity in momentum transfer than the Lehmann ellipse. A representation, the generalization of the Mandelstam representation to this case, is written down, and unitarity used to determine the spectral function.
A Pilot Study of Blood Epinephrine Levels and CREB Phosphorylation in Men Undergoing Prostate Biopsies

Purpose In mouse models of prostate cancer, increased epinephrine levels accelerated tumor growth via the beta2-adrenoreceptor/PKA signaling pathway. It is unknown, however, whether men experience increased epinephrine levels sufficient to activate the beta2-adrenoreceptor/PKA pathway in the prostate gland. We measured epinephrine levels in blood samples collected immediately prior to prostate biopsies and measured phosphorylation of S133CREB (PKA site), S112BAD, T202/Y204ERK, and S473 Akt in prostate biopsy tissue samples.
Self-limited hemolysis due to anti-D passenger lymphocyte syndrome in allogeneic hematopoietic stem cell transplantation.

Self-limited hemolysis due to anti-D passenger lymphocyte syndrome in allogeneic hematopoietic stem cell transplantation
The Biotinyl Domain of Escherichia coli Acetyl-CoA Carboxylase EVIDENCE THAT THE “THUMB” STRUCTURE IS ESSENTIAL AND THAT THE DOMAIN FUNCTIONS AS A DIMER

Biotin carboxyl carrier protein (BCCP) is the small biotinylated subunit of Escherichia coli acetyl-CoA carboxylase (ACC), the enzyme that catalyzes the first committed step of fatty acid synthesis. Similar proteins are found in other bacteria and in chloroplasts. E. coli BCCP is a member of a large family of protein domains modified by covalent attachment of biotin to a specific lysine residue. However, the BCCP biotinyl domain differs from many of these proteins in that an eight-amino acid residue insertion is present upstream of the biotinylated lysine. X-ray crystallographic and multidimensional NMR studies show that these residues constitute a structure that has the appearance of an extended thumb that protrudes from the otherwise highly symmetrical domain structure. I report that expression of two mutant BCCPs lacking the thumb residues fails to restore growth and fatty acid synthesis to a temperature-sensitive E. coli strain that lacks BCCP when grown at nonpermissive temperature. Alignment of BCCPs from various organisms shows that only two of the eight thumb residues are strictly conserved, and amino acid substitution of either residue results in proteins giving only weak growth of the temperature-sensitive E. coli strain. Therefore, the thumb structure is essential for the function of BCCP in the ACC reaction and provides a useful motif for distinguishing the biotinylated proteins of multisubunit ACCs from those of enzymes catalyzing other biotin-dependent reactions. An unexpected result was that expression of a mutant BCCP in which the biotinylated lysine residue was substituted with cysteine was able to partially restore growth and fatty acid synthesis to the temperature-sensitive E. coli strain. This complementation was shown to be specific to BCCPs having native structure (excepting the biotinylated lysine) and is interpreted in terms of dimerization of the BCCP biotinyl domain during the ACC reaction.
Glycosaminoglycan Sulfation in Human Osteoarthritis DISEASE-RELATED ALTERATIONS AT THE NON-REDUCING TERMINI OF CHONDROITIN AND DERMATAN SULFATE

Chondroitin lyase products of aggrecan and small proteoglycans from normal and osteoarthritic cartilages were analyzed for chain internal Δdisaccharides and terminal mono- or disaccharides. Chondroitin and dermatan sulfate chains from arthritic cartilages were of essentially normal size and internal sulfation but had significantly altered sulfation of the terminal residues. Whereas in normal cartilage, ∼60% of terminal GalNAc4S was 4,6-disulfated, it was reduced to ∼30% in osteoarthritic cartilage. This is most likely due to a lower terminal GalNAc4,6S-disulfotransferase activity and reveals that metabolic changes in osteoarthritis can affect this distinct sulfation step during chondroitin and dermatan sulfate synthesis. GlcAβ1,3GalNAc6S-, the mimotope for antibody 3B3(−), was present on ∼8 and ∼10% of chains from normal and osteoarthritic cartilages, respectively. 3B3(−) assayed by immunodot blot was within the normal range for most osteoarthritic samples, with only 5 of 24 displaying elevated reactivity. This resulted not from a higher content of mimotope, but possibly from other structural changes in the proteoglycan that increase mimotope reactivity. In summary, chemical determination of sulfation isomers at the non-reducing termini of chondroitin and dermatan sulfate provides a reliable assay for monitoring proteoglycan metabolism not only during normal growth of cartilage but also during remodeling of cartilage in osteoarthritis.
Spectral Reference Detector For The Visible To 12-microM Region; Convenient, Spectrally Flat.

A convenient spectral reference detector for the visible to 12-μm region has been developed. The device consists of a large area PVF2 pyroelectric detector enclosed in a hemispherical light trap. Based on theoretical and experimental evaluations, the detector response is independent of wavelength to ±1% over this spectral range.
Food Marketing and Childhood Obesity — A Matter of Policy

Everyone knows that American children are becoming fatter, but not everyone agrees on the cause. Dr. Marion Nestle asks, is food marketing responsible? The author discusses childhood obesity and the marketing of food to children.
The eight most frequent blood-borne infectious agents affecting the placenta and fetus

Among the large number of infectious agents which can be found in the blood of pregnant women, there are eight (other than HIV) which cause placental and fetal ill effects with regularity. These are the agents of: syphilis and listeria; rubella, cytomegalovirus and parvovirus; toxoplasmosis, Chagas' disease, and malaria. Together, they cause significant clinical problems in many parts of the world, including abortions and stillbirths, intrauterine growth retardation, premature delivery, congenital malformations, and acute disease in the neonate or chronic sequelae involving many different organs in the infected progeny. Important aspects related to the eight most frequent organisms are presented. They include the microbiology, epidemiology, and clinical aspects in the pregnant women and possible untoward effects on the fetus and newborn, as well as prenatal preventive and therapeutic approaches (if available) and placental pathological features. Also noted in this synoptic review are the particular lessons learned from each of these eight agents and the important questions raised. It can be surmised right away that several factors will affect the incidence encountered with each of these agents. These include relevant socio-cultural-economical features and local public health control measures, as well as the relative epidemicity or endemicity of the infectious agent in a particular geographical site. SYPHILIS (Treponema pallidum)
Development Of A Non-Contact Diffuse Optical Spectroscopy Probe For Extraction Of Tissue Optical Properties

We developed a non-contact diffuse optical spectroscopy probe for extraction of tissue optical properties to mitigate the effects of probe contact pressure. Auto-focusing and cross polarization mechanisms improve depth of focus and reduce specular reflection.
The More Things Change. . . : Metamorphoses and Conceptual Structure*

Given that mythmakers must construct stories that are comprehensible to their audience, it is reasonable to expect stories to be conceptually natural even when their topics deal with the supernatural. Thus, as stories are adapted to human conceptual structure, they should reflect characteristics of that structure. An examination of the types of magical transformations in Ovid's Metamorphoses and Grimms' Fairy Tales suggests that this is the case. It was possible to predict the patterns of transformations on the basis of structural properties of ontological knowledge, which is knowledge of the basic categories of existence (e.g., conscious beings, animals, plants, events). Other characteristics of the transformations seem to reflect the conceptual distinction between animates and inanimates as well as the relative prototypicality of various taxonomic classes of animals. It appears that aspects of conceptual structure can constrain patterns of thinking even during “the willing suspension of disbelief.”
Customization of milled zirconia copings for all-ceramic crowns: a clinical report.

Generically milled zirconia copings for all-ceramic crowns may not provide optimal thickness and form for the coping or the porcelain veneer. This article describes the customization of milled zirconia copings to provide even and controlled porcelain thickness with the aim of decreasing cohesive porcelain fracture and other failures. A full-contour waxing and cut back in conjunction with a dual-scan technique was used to ensure adequate coping thickness, adequate, even porcelain thickness, and butt joints at the porcelain-to-coping junctions. (J Prosthet Dent 2008;99:169-173)
Malignant gastric carcinoid tumor and morbid obesity

Recently, Kassir et al. reported the incidental finding of carcinoid tumor in 2 patients undergoing gastric bypass [1]. A few previously reported case studies have suggested an association between obesity and a higher incidence of carcinoid tumor [2–4]. Carcinoid tumor is rare but is the most common gastrointestinal endocrine neoplasm. Gastric carcinoids account for less than 1% of all carcinoid tumors and less than 2% of all gastric neoplasms, with an incidence of 2 per million in the general population [1–4]. We recently performed an analysis of the incidence of carcinoid tumors in patients undergoing bariatric surgery. To better examine the incidence of carcinoid tumor in this population, cases of laparoscopic sleeve gastrectomy for morbid obesity (CPT code: 43775) between January 2010 and December 2012 were extracted from the American College of Surgeons–National Surgical Quality Improvement Program (ACS-NSQIP) database [5]. Among them, patients with a diagnosis of malignant carcinoid tumor of the stomach (ICD-9 code: 209.23) were examined. Of the 11,320 extracted laparoscopic sleeve gastrectomy cases, 5 patients (0.04%) had a malignant gastric carcinoid tumor. The incidence of carcinoid tumor in this series (442 per million) was higher than the general population (2 per million). Carcinoid patients had a male/female ratio of 1:4, a mean age of 56.0 19.0 years, a mean body mass index of 35.8 6.1 kg/m, and a median American Society of Anesthesiologists score of 2. There were no major 30-day postoperative complications, reoperations, or readmissions. Although rare, a higher incidence of malignant gastric carcinoid tumor in morbidly obese patients than in general population was observed. This finding raises suspicion about the influence of obesity on the pathogenesis of
The accommodation of strain and particle size broadening in rietveld refinement; its application to de-deuterided LaNi5 alloy

Abstract It has been demonstrated that the neutron diffraction pattern of dedeuterided LaNi5 exhibits severe anisotropic line broadening. The halfwidths can be modelled by a modified Rietveld refinement in a simple and physically plausible manner by making use of a peak shape function accounting for particle size and strain broadening. The particle size of the dehydrided metal is approximately 700 A, at least an order of magnitude smaller than the virgin annealed metal. There is a slight shift in the cell constants and a general increase in the temperature factors of the de-deuterided alloy.