cssi/SciSciGPT-SciSciNet huggingface dataset:
Spaces with Curvature Bounded Below

After the seminal work of Gromov (see [G1],[GLP]), questions of this type, with various assumptions on curvatures, and other geometric characteristics, have been receiving much attention. Cheeger, Gromov, and Fulraya developed a farreaching theory of collapse under the two-sided curvature bounds (see [CFG]). One of the simplest conclusions of this theory is that the limit space M in this case has a stratification, each stratum being a totally geodesic Riemannian manifold. (This stratification is nontrivial unless Mj admits a structure of locally trivial fibration over M.) This conclusion can be explained by the following argument (see [GLP, 8.30] for details). Suppose that Mj have sectional curvatures between —1 and 1, and let pj G Mj converge to some point p G M. Then the balls Bj of radius 7r/2 centered at pj are covered by convex balls Bj of the same radius in the tangent spaces at pj, endowed with the lifted metrics. The sequence Bj has the same curvature bounds and, in addition, a uniform lower bound on the injectivity radius; therefore its limit B is a manifold. Now each Bj is a quotient of Bj by an isometric (pseudo)group action, hence a ball B in M centered at p must be a quotient of B by the limit action; this leads to a stratification of B with totally geodesic strata.
Scientific Technology and the Human Condition

Society applauds the recent advancements of scientific technology in fields such as medicine, energy, and communication. While humankind profits in many ways from this technology, a few voices are heard cautioning society to consider the implications of these developments. This paper discusses the gulf which appears to exist between scientific technology and the human condition. Reasons for this gulf are: I ) the failure to develop a philosophy of science in which human values, and aspirations are viewed within the context of scientific technology, 2) the reductionist approach to science in which the parts are emphasized at the expense of the whole; and, 3) the failure to conceptualize behavior in such a way that the situational or contextual variables of technology are understood. The paper concludes by proposing a social ecological model of human behavior which allows for the integration of technology with the human condition.
Fuel cladding chemical interaction in metallic sodium fast reactor fuels: A historical perspective

Abstract Starting in the 1950s, significant efforts have been devoted to developing metallic nuclear fuels for use in sodium fast reactors. During irradiation, one performance limitation for this type of fuel is fuel cladding chemical interaction (FCCI), which occurs after the fuel swells and contacts the cladding. This can cause formation of interaction zones on the cladding inner surface that have low mechanical strength and that can contain relatively low-melting phases. Significant in-pile and out-of-pile research has been performed to improve understanding of how FCCI affects fuel performance and also to identify ways to mitigate and possibly eliminate this phenomenon. In celebration of the diamond anniversary for the Journal of Nuclear Materials, this paper reviews and highlights key aspects of the metallic fuel FCCI research performed over the last 60 years, and discusses some of the most current research being performed today.
Intravascular triglyceride lipolysis becomes crystal clear

The ability to store surplus calories as fat for use during fasting or periods of increased energy demands is a fundamental process required for survival of all species. Fat consumed in the diet is incorporated into triglyceride-rich lipoproteins (chylomicrons) in the intestine for delivery to peripheral tissues. The liver also secretes triglyceride-rich very low-density lipoproteins (VLDLs). Chylomicrons and VLDL triglycerides are hydrolyzed within capillaries by lipoprotein lipase (LPL) (1), releasing lipids for storage and utilization by vital tissues. The processing of lipoproteins by LPL has been studied intensively for more than a half century and has proved highly relevant to clinical medicine. A complete deficiency of LPL results in an inability to hydrolyze the triglycerides in chylomicrons and VLDLs, resulting in severe hypertriglyceridemia (chylomicronemia) and a substantial risk of acute pancreatitis (2). Partial deficiencies in LPL cause mild to moderate hypertriglyceridemia and increased risk for coronary artery disease (3, 4). The ability of LPL to hydrolyze plasma triglycerides is absolutely dependent on glycosylphosphatidylinositol (GPI)-anchored high-density lipoprotein–binding protein 1 (GPIHBP1), a GPI-anchored endothelial cell protein that binds LPL and tethers it to the luminal surface of capillaries (1). GPIHBP1 deficiency severely impairs triglyceride processing and causes severe hypertriglyceridemia (indistinguishable from that caused by LPL deficiency) (5, 6). Despite intensive research, structures for LPL and GPIHBP1 have been elusive. However, in PNAS, Birrane et al. (7) report the crystal structure of the LPL–GPIHBP1 complex. This accomplishment culminates a decade of collaborative studies by Stephen G. Young and collaborators that have focused on defining GPIHBP1 function in triglyceride metabolism. LPL activity was first reported by Hahn (8) in 1943, who described the appearance of a lipemia clearing factor in dogs after an injection of heparin. The activity of LPL is regulated by apolipoproteins on the surface of lipoproteins (most notably … [↵][1]1Email: jay.horton{at}utsouthwestern.edu. [1]: #xref-corresp-1-1
Examining attitudes, norms, and perceived control: Young African American males’ views of social media as a mode for condom use education

Gender-based data indicates that within-race STI rate disparities exist for young African Americans males, (YAAMs) ages 18 to 24. Social media may prove to be a valuable tool for delivering theory-...
(345) The Neuropeptide TLQP-62 Induces Calcium Transients in Primary Afferent Neurons

The neurosecretory protein VGF (non-acronymic) is rapidly and robustly upregulated by primary somatosensory afferent neurons following peripheral nerve damage. VGF is proteolytically processed to yield a number of bioactive peptides, including the C-terminal peptide TLQP-62. Our work demonstrates that spinal TLQP-62 increases after nerve injury and that immunoneutralization of C-terminal VGF peptides attenuates the development of mechanical allodynia. This peptide has been shown to induce BDNF-dependent neuronal plasticity in the hippocampus. We have shown that TLQP-62 induces potentiation of glutamatergic responses in a subset of dorsal horn neurons and exposure of spinal cord slices to TLQP-62 increases TrkB phosphorylation, suggesting that TLQP-62 may facilitate BDNF release. Since primary afferent neurons are a potential source of spinal BDNF, we examined the effects of TLQP-62 on these neurons. Using mice that express a genetically encoded calcium indicator restricted to primary afferent neurons (Pirt-GCamp3 mice), we observed that TLQP-62 induced calcium transients in a subset of primary afferent fibers in the dorsal horn of spinal cord slices. The responses occurred immediately after TLQP-62 exposure and were sustained during prolonged exposure. TLQP-62 also induced calcium transients in DRG cultures, both in capsaicin-responsive neurites, as well as in neurites that did not respond to capsaicin. Ongoing work is investigating the functional consequences of these TLQP-62 effects and their relationship to BDNF via patch-clamp and BDNF-pHluorin imaging, respectively. Our observations of TLQP-62-induced calcium responses in the processes of primary afferent neurons are consistent with the idea that the peptide may modulate neurotransmitter release.
Reaction of [Os(en)(2)O(2)](2+) with photolyzed [Mo(CN)(8)](4-) in water

The photolysis of aqueous [Mo(CN)8]4- with 4000−4800 A light gives [Mo(CN)7OH2]3-, which, in the presence of trans-[Os(en)2O2]2+, produces [(CN)7Mo−O−Os(en)2-O−Mo(CN)7]4-. This complex ion has an intense charge-transfer absorption band centering at 6950 A and the formation constants are Kf2≫Kf1. The X-ray structure shows large Mo−O and Os−O bond length changes compared to the parent ions.
Agent Modeling to Support Allocation Decisions in Mobile Cyber-Physical Systems

This paper addresses the conceptual design of Mobile Cyber-Physical Systems (MCPS) forming a part of a convoy of similar vehicles operating as a system of systems. MCPS are a type of cyber-physical system with intelligent control that may be realized by cyber components, human operators or a combination of the two. Traditional systems engineering modeling and design methodologies are not adequate for representing the intelligent behaviors exhibited by MCPS without early commitment to design solutions. As a result, many of the important design decisions made during conceptual design have inadequate model support. This paper presents an agent-based model framework specifically for MCPS during conceptual design. The agents are abstract logical components corresponding to elements of the MCPS vehicle. An important part of the model is representation of goals as a driver of intelligent behaviors. We describe the model using a current Army system, the Palletized Loading System (PLS).
The Effect of Large-Scale Performance-Based Funding in Higher Education.

The use of performance-based funding that ties state higher education appropriations to performance metrics has increased dramatically in recent years, but most programs place at stake a small perc...
Poisson Process and Shot Noise

While the Wiener process has continuous sample paths and continuously changes by small increments, the Poisson process is integer valued with discontinuous sample paths and changes infrequently by unit increments. So, it is well adapted to model discrete random phenomena, such as photon counts in optics, the number of tasks processed by a computer system, or random spikes in a neural pathway. Like the Wiener process, the Poisson process has independent increments and can be constructed in several equivalent ways, which are described in Sect. 7.2. The times at which the Poisson process undergoes jumps are called epochs, and the interarrival times (the time between two epochs) are exponentially distributed. In this context, as explained in Sect. 7.3, the memoryless property of exponential distributions has an interesting consequence concerning the distribution of the residual time until the occurrence of the next epoch after an arbitrary reference time. As shown in Sect. 7.5, Poisson processes have also the the interesting feature that they remain Poisson after either merging, or splitting randomly into two lower rate processes. Finally, Sect. 7.6 examines the statistical properties of shot noise, which is a form of noise occurring in electronic devices, such as vacuum tubes or optical detectors, when electrons or photons arriving at random instants (modeled typically by the epochs of a Poisson process) trigger an electronic circuit response.
Current and emerging treatments for acute promyelocytic leukemia

Introduction: The introduction of all-trans retinoic acid (ATRA) and arsenic trioxide (ATO) to clinical practice revolutionized the APL therapy and allowed development of chemotherapy-free regimen ...
Parenting and Children's Executive Function Stability Across the Transition to School

When children transition to school between the ages of 4 and 6 years, they must learn to control their attention and behavior to be successful. Concurrently, executive function (EF) is an important skill undergoing significant development in childhood. To understand changes occurring during this period, we examined the role of parenting in the development of children's EF from 4 to 6 years old. Participants were mother and child dyads (N = 151). Children completed cognitive tasks to assess overall EF at age 4 and age 6. At both time points, mothers and children completed interaction tasks which were videotaped and coded to assess various parenting dimensions. Results indicated that children with high EF at age 4 were more likely to have high EF at age 6. In addition, results suggested that higher levels of positive parenting across the transition to school promote stability of individual differences in EF.
The Radio AGN Population Dichotomy: Green Valley Seyferts Versus Red Sequence Low-Excitation Active Galactic Nuclei

Radio outflows of active galactic nuclei (AGNs) are invoked in cosmological models as a key feedback mechanism in the latest phases of massive galaxy formation. Recently, it has been suggested that the two major radio AGN populations—the powerful high-excitation, and the weak low-excitation radio AGNs (HERAGN and LERAGN, respectively)—represent two earlier and later stages of massive galaxy buildup. To test this, here we make use of a local (0.04 < z < 0.1) sample of ~500 radio AGNs with available optical spectroscopy, drawn from the FIRST, NVSS, SDSS, and 3CRR surveys. A clear dichotomy is found between the properties of low-excitation (absorption line AGN and LINERs) and high-excitation (Seyferts) radio AGNs. The hosts of the first have the highest stellar masses, reddest optical colors, and highest mass black holes but accrete inefficiently (at low rates). On the other hand, the high-excitation radio AGNs have lower stellar masses, bluer optical colors (consistent with the "green valley"), and lower mass black holes that accrete efficiently (at high rates). Such properties can be explained if these two radio AGN populations represent different stages in the formation of massive galaxies, and thus are also linked to different phases of the "AGN feedback."
Privacy Preserving Policy Framework: User-Aware and User-Driven

Privacy policies outline and structure data collection and access management for online services or websites. These policies are often too long, complex, and convoluted for an average internet user to understand which is a factor in why these policies are ignored. Prior work has mostly focused on improving the accessibility of these privacy policies. Here we focus on making the policies more resemble the negotiation they are supposed to represent by proving flexibility to people. An example is a website which offers various services such as photo, video, or location sharing, where the people are required to either accept the privacy policy to access all the services provided by the website or be prevented from using any of the services. Our goal is to map privacy policy statements to the distinct services offered by a website allowing people to agree for only the services they wish to use. By not agreeing to a policy statement, the access would be denied only on the corresponding service instead of following the all or none mechanism. Additionally, this would also prevent the website from collecting data from people for a particular service which they have no current or future desire to use, in accordance with the principle of data collection minimization. We propose a privacy policy framework to promote transparency for consumers, credibility and trust building for the organization, and clarity in data storage for the developers. Our modular service-policy map for developers allow them to easily associate new features to the corresponding privacy policy section. Modularizing enables developers, organizations, customers, and other stakeholders to understand how specific services correspond with individual data compilations. With the current ongoing debate of data access strategies in social media platforms, our initial framework is based on Facebook’s privacy policy because of the diversity in services that the platform offers. However, the framework can be widely applied across various social media, business, and health care policies. Finally, through pilot interviews with existing consumers, we report on the initial validity testing of our proposed framework. Our early findings are promising in terms of meeting the goals of promoting privacy awareness and increasing trust in organizations' privacy policies.
Effects of moderate sleep restriction during 8-week calorie restriction on lipoprotein particles and glucose metabolism.

Study objectives This study examined how glucose, glucose regulatory hormones, insulin sensitivity, and lipoprotein subclass particle concentrations and sizes change with sleep restriction during weight loss elicited by calorie restriction. Methods Overweight or obese adults were randomized into an 8-week calorie restriction intervention alone (CR, n = 12; 75% female; body mass index = 31.4 ± 2.9 kg/m2) or combined with sleep restriction (CR+SR, n = 16; 75% female; body mass index = 34.5 ± 3.1 kg/m2). Participants in both groups were given the same instructions to reduce calorie intake. Those in the CR+SR group were instructed to reduce their habitual time-in-bed by 30-90 minutes 5 days each week with 2 ad libitum sleep days. Fasting venous blood samples were collected at pre- and post-intervention. Results Differential changes were found between the two groups (p = 0.028 for group × time interaction) in glucagon concentration, which decreased in the CR group (p = 0.016) but did not change in CR+SR group. Although changes in mean HDL particle (HDL-P) size and visfatin concentration were not statistically different between groups (p = 0.066 and 0.066 for group×time interaction, respectively), mean HDL-P size decreased only in the CR+SR group (Cohen's d = 0.50, p = 0.022); visfatin concentrations did not change significantly in either group but appeared to decrease in the CR group (Cohen's d = 0.67, p = 0.170) but not in the CR+SR group (Cohen's d = 0.43, p = 0.225). Conclusion These results suggest that moderate sleep restriction, despite the presence of periodic ad libitum sleep, influences lipoprotein subclass particles and glucose regulation in individuals undergoing calorie restriction.Clinical trial registration: ClinicalTrials.gov (NCT02413866, Weight Outlooks by Restriction of Diet and Sleep).
A Simple Method for Eye Protection During Prone Positioning for Craniofacial Surgery.

Surgery in the prone position risks vision loss due to a number of factors. Craniofacial surgery poses an even greater risk due to the anatomical and physiological makeup of these patients. Here, w...
Anal adenocarcinoma: case report, literature review and comparative survival analysis

Introduction Anal adenocarcinoma is a rare malignancy with a poor prognosis. Methods We present a case of rare anal adenocarcinoma in a patient with normal screening colonoscopy. Using the Surveillance, Epidemiology and End Result database between 2000 and 2016, we performed survival analysis among individuals>20 years old comparing anal and rectal cancers. Results Survival analysis showed that anal adenocarcinoma is associated with worse outcomes compared with rectal adenocarcinoma and anal squamous cell carcinoma. Discussion This case and survival data illustrate the importance of prompt investigation of symptoms irrespective of colorectal cancer screening status with careful attention to examination of the anal area.
Three-Dimensional Printing of Patient-Specific Heart Valves: Separating Facts From Fiction and Myth From Reality

The development of prosthetic heart valves by Dr. Charles Hufnagel in 1952 was a major clinical innovation; however, it was not an ideal solution. Mechanical prosthetic heart valves are rigid, immunogenic, require anticoagulation, do not grow with the patient, and have a finite life. 1 An ideal prosthetic valve should overcome all these limitations. Considering the prevalence of valvular heart disorders, there is considerable interest in the creation of patient-specific heart valves. Following the introduction of three-dimensional (3D) printing in 1986 by Chuck Hill, rapid advances in multimodality 3D imaging and modeling have led to a generation of tangible replicas of patient-specific anatomy. The science of organogenesis has gained importance for a multitude of valid reasons: as an alternate source of organs, for realistic drug testing, as an alternative to animal testing, and for transplants that grow with the patient. What scientists imagined to be seemingly impossible in the past now seems just a step away from becoming a reality. However, due to the disruptive nature of this technology, often there are commercially-motivated claims of originality and overstatement of the scope and applicability of 3D printing. It often is difficult to separate fact from fiction and myth from reality. In this manuscript, the authors have reviewed the historic perspective, status of the basic techniques of organogenesis with specific reference to heart valves, and their potential.
Technique Corner: Posterolateral Corner Reconstruction

Posterolateral corner injuries can be challenging to diagnose and require a thorough evaluation of relevant history, physical exam, and imaging. If left untreated, these injuries can result in chronic knee pain, instability, and inability to return to work or sports. This chapter will review basic posterolateral corner anatomy and biomechanics, operative indications, surgical techniques, postoperative rehabilitation, outcomes, and potential complications to provide surgeons a framework for managing patients with these complex injuries. The authors’ preferred technique is a fibula-based posterolateral corner reconstruction utilizing a single Achilles tendon allograft to reconstruct the lateral collateral ligament, popliteus tendon and popliteofibular ligament, which is performed in conjunction with a posterolateral capsular shift. The technique is based on anatomic sockets and graft placement. Furthermore, since posterolateral corner injuries are often part of a multiligamentous injury pattern, it is important to address concurrent anterior cruciate and posterior cruciate ligament injuries at the time of surgery, because anteroposterior instability has been shown to increase forces on the posterolateral corner reconstruction and may result in graft failure. Postoperative rehabilitation follows a staged approach progressing from restoring knee range of motion to building muscular endurance, strength, and power. Short- to mid-term follow-up studies show excellent clinical and functional outcomes, and low risk for subsequent revision surgery.
Bmp2 conditional knockout in osteoblasts and endothelial cells does not impair bone formation after injury or mechanical loading in adult mice

Post-natal osteogenesis after mechanical trauma or stimulus occurs through either endochondral healing, intramembranous healing or lamellar bone formation. Bone morphogenetic protein 2 (BMP2) is up-regulated in each of these osteogenic processes and is expressed by a variety of cells including osteoblasts and vascular cells. It is known that genetic knockout of Bmp2 in all cells or in osteo-chondroprogenitor cells completely abrogates endochondral healing after full fracture. However, the importance of BMP2 from differentiated osteoblasts and endothelial cells is not known. Moreover, the importance of BMP2 in non-endochondral bone formation such as intramembranous healing or lamellar bone formation is not known. Using inducible and tissue-specific Cre-lox mediated targeting of Bmp2 in adult (10-24 week old) mice, we assessed the role of BMP2 expression globally, by osteoblasts, and by vascular endothelial cells in endochondral healing, intramembranous healing and lamellar bone formation. These three osteogenic processes were modeled using full femur fracture, ulnar stress fracture, and ulnar non-damaging cyclic loading, respectively. Our results confirmed the requirement of BMP2 for endochondral fracture healing, as mice in which Bmp2 was knocked out in all cells prior to fracture failed to form a callus. Targeted deletion of Bmp2 in osteoblasts (osterix-expressing) or vascular endothelial cells (vascular endothelial cadherin-expressing) did not impact fracture healing in any way. Regarding non-endochondral bone formation, we found that BMP2 is largely dispensable for intramembranous bone formation after stress fracture and also not required for lamellar bone formation induced by mechanical loading. Taken together our results indicate that osteoblasts and endothelial cells are not a critical source of BMP2 in endochondral fracture healing, and that non-endochondral bone formation in the adult mouse is not as critically dependent on BMP2.
Technology as a Medium for Elementary Preteachers' Problem-Posing Experience in Mathematics

SERGEI ABRAMOVICH AND EUN KYEONG CHOState University of New York, College at PotsdamUSAabramovs @potsdam.educhock@potsdam.eduThis article attempts to extend current research and develop-ment activities related to the use of technology in problemposing, to early grades mathematics. It is motivated by theauthors' work with elementary preservice teachers towardthis goal, both at the graduate and undergraduate levels. NewYork State Learning Standards for K-4 mathematics serve asa background for technology-enabled learning. Spreadsheet-based environments designed by the authors (using MicrosoftExcel 2004) are introduced from a tool kit perspective, en-abling a meaningful combination of manipulative and com-puting activities by elementary preteachers and their studentsalike.One of the central tenets of the current reform movement in mathemat-ics education holds that appropriate use of tools of technology is integral tothe teaching and learning of mathematics at all grade levels. In the contextof preparing teachers for the 21st century classrooms, the word "appropri-ate" may include the notion of teacher as a technologically minded curric-ulum developer, capable of exploring-and helping his/her students to ex-plore-new avenues in mathematical content; in particular, being skillful inthe use of technology for posing and solving problems. This puts mathemat-ics educators involved in the preparation of teachers for elementary schoolsin a unique position because such technology-enabled changes in pedagogymust be feasible from the very outset in the chain of children's educationalexperiences.
AC coupled quadrature doppler radar displacement estimation

While cardiopulmonary rates can be estimated by various radar architectures and demodulation methods, a higher precision instrumentation is needed for accurate physiological waveform tracking and displacement estimation. It has been demonstrated that high accuracy can be achieved with DC coupled quadrature Doppler radar signal using arctangent demodulation. However, DC coupling typically increases system complexity. This paper presents a calibration of AC coupled baseband signals, to eliminate DC offset and achieve high accuracy displacement measurements without adding to radar architecture complexity.
Nucleic acid binding agents exert local toxic effects on neurites via a non‐nuclear mechanism

The mechanism by which drugs that target nucleic acids cause neurotoxicity is not well described. We characterized the neurotoxicity of Hoechst 33342 (bis-benzimide), a common cell permeable nuclear dye, in primary neuronal cultures. The mechanism of cell death was not apoptotic, as death is rapid, not accompanied by typical nuclear morphological changes, and is insensitive to inhibitors of transcription, translation and caspase activity. In addition, free-radical scavenging agents failed to attenuate cell death, and damage was not accompanied by mitochondrial dysfunction. Neuronal processes of cells exposed to Hoechst 33342 display dramatic fragmentation prior to cell death. When this compound was applied selectively to the distal axons of sympathetic neurons grown in compartmented cultures, the distal axons were destroyed. However, the proximal processes present in the cell body compartment were spared, demonstrating direct axonal toxicity rather than a remote effect of nuclear dysfunction. Other cell-permeable nucleic acid binding dyes similarly caused rapid dendritic and axonal toxicity. The hypothesis that these nucleic acid binding dyes target RNA localized to dendrites and axons is supported by observations that RNaseV1 induced similar, rapid neurite fragmentation. We conclude that the neurotoxic effects of nucleic acid binding compounds are mediated, at least in part, by direct neurite injury, which does not require involvement of the cell body and nucleus.
Fine Particles and Thin Films

This chapter contains sections titled: Introduction Single-Domain vs Multi-Domain Behavior Coercivity of Fine Particles Magnetization Reversal by Spin Rotation Magnetization Reversal by Wall Motion Superparamagnetism in Fine Particles Superparamagnetism in Alloys Exchange Anisotropy Preparation and Structure of Thin Films Induced Anisotropy in Films Domain Walls in Films Domains in Films Problems
The Hot Phase in the Galactic Disk

Spectra of about 150 early-type stars in the disk of the Milky Way recorded by the Far Ultraviolet Spectroscopic Explorer (FUSE) reveal absorption features from interstellar O VI, a tracer of collisionally ionized gases at temperatures near 300,000 K. (Hotter material is better sensed by its diffuse x-ray emission.) The FUSE survey indicates that hot gas in the plane of the Galaxy yields an average density n(O VI) = 1.7 X 10^{-8} cm^{-3}, a value consistent with earlier results from the Copernicus satellite, but at great distances there is a large dispersion in the measurements from one line of sight to another. This dispersion indicates that O VI absorbing regions probably have a broad distribution of sizes, perhaps giving a power-law behavior for column densities. Comparisons of O VI with other Li-like ions should give some guidance on the nature and origin of the O VI-absorbing regions, but poor correspondences in the velocity profile shapes will complicate the interpretations.
Estabilidad y variabilidad en la adquisición de seis hitos motores durante la infancia temprana

El proposito del trabajo es mostrar, mediante evidencia proveniente de estudios cientificos con infantes sanos y bien nutridos y con poblaciones infantiles con altas tasas de desnutricion e infecciones, que el orden en que se presenta la emergencia de los hitos motores gruesos es estable en estos dos grupos. Por otro lado, la variabilidad en la edad de adquisicion de los mismos entre los infantes en riesgo es mayor que en los ninos sanos y bien nutridos. Los resultados sugieren que factores geneticos pueden contribuir a la estabilidad en el orden de emergencia y que factores socioculturales y de salud pueden haber contribuido al origen de las diferencias en la edad de adquisicion. La informacion tiene importancia teorica y aplicada para la evaluacion del desarrollo motor con el proposito objetivo de identificar los determinantes de dicha area del desarrollo
A home visit programme to teach medical students about children with special needs.

Objectives During an 8-week clinical rotation in paediatrics and child health, fifth-year medical students at the University of Cape Town are required to visit children with special needs in their homes. The home visit allows students to learn, first-hand, from children with special needs and their families about living with chronic disease and disability. Design During 1998 students anonymously completed home visit evaluation questionnaires (90% response rate, 160/177). Through verbal presentations, students are assessed on their ability to make a comprehensive evaluation of the impact of chronic disease and disability on a child and family. Setting University of Cape Town Medical School. Subjects Fifth-year medical students. Results A content analysis of verbal presentations found students were more likely to identify medical, psychosocial and economic than spiritual and ethical issues. As a learning experience, 37% (n=57) of students rated the home visit as ‘extremely worthwhile’, 62% (n=100) found it ‘worthwhile’ and only 2% (n=3) felt it was ‘a waste of time’. Most (97%, n=155) students felt the programme should continue in the future. Conclusions As an educational tool, home visiting grounds learning in families’ experience and encourages reflection beyond the medical aspects of care for children with special needs.
Chibby forms a homodimer through a heptad repeat of leucine residues in its C-terminal coiled-coil motif

Background The Wnt/β-catenin signaling pathway plays crucial roles in embryonic development and in maintenance of organs and tissues in adults. Chibby (Cby) is an evolutionarily conserved molecule that physically interacts with the key downstream coactivator β-catenin and represses its transcriptional activation potential. Although Cby harbors a predicted coiled-coil motif in the C-terminal region, its molecular nature and functional importance remain largely unexplored.
Female football players, the sport ethic and the masculinity-sport nexus

Sport has traditionally been considered a male arena; however, women's participation continues to grow. One aspect of sport that remains relatively unaffected by women's inclusion is the sport ethic – the masculine sporting ideals of sacrificing one's body for sport, and ‘playing through pain’. Using a gendered lens, this study explores the extent to which female professional tackle football players on two Northern California teams have adopted the masculine sport ethic. Through interviews with 35 female professional football players, we find that for the most part female football players accept the masculine-defined culture of football complete with pain management techniques and athletic ideals that motivate them to continue playing despite pain and/or injury. Although women comply with the sport ethic in responding to pain and injury in football, results suggest that there are a few ways that women do resist the status quo.
Mass flow through a horizontal vent in an enclosure due to pressure and density differences

A detailed experimental study is undertaken to understand the basic nature of the mass flow through a horizontal vent in an enclosure due to differences in pressure and density across the vent. This flow is of particular interest in enclosed regions with a heat source such as fire, whose growth and development depend on the flow of oxygen through the vent. In this study, fresh and saline water are employed to simulate the density differences that arise due to temperature rise in the enclosure. An externally imposed pressure difference is also exerted and the flow rates resulting from the combined effect of pressure and buoyancy are measured. In the absence of a pressure difference, but with heavier fluid overlying lighter fluid, a bidirectional flow arises across the vent, between the two regions, due to buoyancy effects. As the pressure in the lower region increases, the flow gradually shifts to a unidirectional flow. The critical pressure, at which transition from bidirectional to unidirectional flow arises, is determined for a range of density differences. The flow rates at relatively large pressure differences can be obtained from existing vent flow models that are based on Bernoulli's equation. However, typical fire conditions lie in the region where both buoyancy and pressure effects are important. Results on the measured flow rates in this region and also some correlations that consolidate the observed trends are presented.
Technologies in Contexts: Implications for Teacher Education

This paper discusses the interaction among school and university contexts, instruction, and individual practice that occurs as telecommunications technology is integrated into teacher education programs. Data from a series of studies of such integration within one university are presented and discussed. A model to guide future research is proposed. ( 2000 Published by Elsevier Science Ltd.
Localized magnetic moments in transition metals and alloys

Abstract The Anderson model generalized to the case of many impurities is studied within an approximation used by Roth in the single impurity case. The treatment attempts to take into account the correlation in the occupancy of the impurity orbital in the limit of infinite Coulomb repulsion. The effect of the interactions between impurities is studied in detail for the two impurity problem. Here one finds the occurrence of localized magnetic moments and their dependence on the character and strength of the interaction quite similar to that obtained in the Hartree-Fock theory with an appropriately chosen value for the Coulomb repulsion. For a given number of electrons in the impurity state, we find a parallel or antiparallel alignment of the moments energetically favorable depending on whether the interaction between the impurities is primarily direct or indirect. The formalism is extended to consider a dilute random alloy, and also transition metals and ordered alloys of transition metals with simple metals.
Suction Blister Epidermal Grafts Combined with CO2 Laser Superficial Ablation as a Good Method for Treating Small‐Sized Vitiligo

BACKGROUND Despite the availability of various new methods to treat vitiligo, surgical methods offer rapid, simple, and safe ways for treating small-sized vitiligo. OBJECTIVE To evaluate the feasibility and efficacy in treating vitiligo using suction blister epidermal grafting (SBEG) combined with CO2 laser epidermal ablation. METHODS Forty patients with small, stable vitiligo were treated using SBEG combined with CO2 laser epidermal ablation and followed up for at least 6 months and up to 10 years. RESULTS Treatment outcomes were excellent for 32 patients (80%), good for four patients (10%), fair for three patients (7.5%), and poor for one patient (2.5%). No scar formation was observed in any patients. Location of the lesions was probably the most important factor in determining the outcomes of transplantation. CONCLUSION This study suggests that SBEG combined with CO2 laser ablation is a rapid, simple, and safe method to treat vitiligo, especially for patients with small and stable vitiliginous lesions.
Theory of Scattering with Large Momentum Transfer

Measurements of elastic p-p scattering for high momentum transfers are noted to follow a simple power law, and it is shown that this law can be understood in terms of an optical model in which the medium is taken to be purely absorptive and to be spatially distributed according to a Yukawa function. (auth)
The 58‐kDa microspherule protein (MSP58), a nucleolar protein, interacts with nucleolar protein p120

Protein p120 is a proliferation-related nucleolar protein which is detectable early in the G1 phase of the cell cycle and peaks early in the S phase. Most human malignant tumors contain much higher levels of protein p120 than normal resting cells. To identify p120-associated protein(s), a yeast two-hybrid screen was carried out using protein p120 as the bait. Two positive clones encoded portions of a novel protein, designated microspherule protein 58 kDa (MSP58). MSP58 mRNA is 1.9 kb and encodes an approximately 58-kDa polypeptide of 462 amino acids as shown by Western blotting of HeLa nucleolar proteins. The mouse MSP58 homolog has 97% amino acid similarity to human MSP58, but no MSP58 homolog was found in the yeast genome. The MSP58 N-terminal region contains serine-rich clusters and its C-terminal region has a coiled-coil domain. In insect Sf9 cells, recombinant p120 and MSP58 proteins associated with each other, confirming the results of the yeast two-hybrid assay. Deletion mutations revealed that the binding of MSP58 to p120 required a previously unrecognized coiled-coil domain within the N-terminal region of p120 and the C-terminal region of MSP58 protein. Immunofluorescence indicated that the MSP58 protein is localized in microspherules in the nucleolus. Anti-MSP58 Ig labeled nucleolar 'caps' when HeLa cells were treated with actinomycin D. When the MSP58 protein was overexpressed in COS-7 cells, the nucleolus became irregularly enlarged, which suggests that MSP58 may affect the size and shape of the nucleolus.
Semiconductor CdS:Mn/ZnS quantum dots for sensing applications

Since past several years, quantum dot (Qdot) nanotechnology has advanced our capabilities towards sensitive and reliable imaging of biological specimens such as cells, tissues etc. It is well understood that surface passivation is extremely important in obtaining bright and photostable Qdots. Traditionally, an inorganic wide band-gap epitaxially-matched shell material (such as ZnS, ZnSe etc.) is used over the Qdot core (such as CdS, CdSe etc.). Surface passivation minimizes surface related defects and improves quantum efficiency as well as photostability. This is also applicable to dopant based Qdots such as CdS:Mn/ZnS Qdots. In this work we present our research data on CdS:Mn/ZnS Qdots that are further surface modified with appropriate organic ligands for selective sensing applications. These ligands are capable of quenching Qdot luminescence via electron transfer process. Qdot luminescence is restored when electron transfer process is blocked. Using this quenching mechanism, we have demonstrated selective sensing of cadmium ions, alkali metal ions and glutathione in a highly sensitive manner.
Building Usage and Learning Styles at the Middle Level.

This article describes how one learning style measurement tool can be used to im prove the instruc tion of middle level learners.
Rural Adaptation in Russia: Who Responds and How Do We Measure It?

Utilizing survey data from 800 households in five regions of Russia, this article attempts to measure adaptation to reform stimuli according to socio-economic strata. While the orthodox literature has emphasized rural resistance to reform, in fact one of the main analytical obstacles is differentiating between adaptive and survival strategies. Time horizon is used as the primary criterion to distinguish between adaptive and survival behaviour. The article analyses adaptive responses by examining the use of rural credit, the operation of a household business, the enlargement of household land plots and a set of attitudes that taken together comprise an ‘entrepreneurial spirit’.
Concluding remarks: symposium on Genetic Susceptibility to Environmental Toxicants.

Abstract The symposium on “Genetic Susceptibility to Environmental Toxicants” provided a state-of-the-art forum on the role of genetic susceptibility involving exposures to occupational, dietary, and other environmental toxicants. While much of the work focused on single gene–environmental interactions, there was a clear understanding that multiple gene polymorphisms in a metabolic pathway would prove to be essential knowledge in better assessing health risks. A clear need to couple these advances with better measures of exposure was also appreciated, along with improved methods to conduct individual risk assessment procedures. The ethics of these new paradigms was also discussed.
A biologically-inspired nanoantenna array

The concept of biomimetic antenna arrays which mimic the hearing mechanisms of insects with hyperacute directional hearing capabilities is extended to nanoantennas operating at optical wavelengths. A silicon-based biomimetic dielectric resonator antenna array operating at a wavelength of 1µm is demonstrated. Using full-wave electromagnetic simulations, the array is shown to exhibit enhanced sensitivity to the direction of arrival of light, compared with regular arrays with similar aperture sizes. This concept presents a novel means of conducting phase coherent measurements at THz, infrared, and optical wavelengths without using phase coherent detectors.
Spatial distributions of the ion to electron temperature ratio in the magnetosheath and plasma sheet

[1] We have used THEMIS measurements to determine how the ion and electron temperatures and their ratio (Ti/Te) change spatially in the magnetosheath and plasma sheet and to identify the processes responsible for the variations. Magnetosheath Ti/Te varies from ∼4–12 with higher ratios observed during larger solar wind speed and at locations closer to the magnetopause. Ti/Te remains almost unchanged as particles flow downstream and cool adiabatically. Across the flank magnetopause from the magnetosheath to a plasma sheet that is cool with abundant cold plasma, temperature and specific entropy for ions and electrons increase significantly while Ti/Teremains similar, indicating that the magnetosheath ions and electrons are non-adiabatically energized with similar proportion while entering the magnetosphere. Within the tail plasma sheet, Ti/Te varies from ∼6 to 10 when plasma is relatively cool to ∼2 to 5 when relatively warm. With this correlation, Ti/Te is higher closer to the flanks and during northward interplanetary magnetic field (IMF), while lower Ti/Te is more often seen during higher AE around midnight. The distinguishably lower Ti/Tefor warmer plasma in the near-Earth plasma sheet is likely due to additional non-adiabatic heating of electrons more than ions as particles move earthward and are adiabatically energized. As particles move into the near-Earth magnetosphere, strengthening magnetic drift brings more hotter ions toward dusk and more hotter electrons toward dawn, resulting in a strong Ti/Tedawn-dusk asymmetry with very high Ti/Te (∼15 to 100) near dusk and very low Ti/Te (∼1) near dawn.
Using occupancy grids for mobile robot perception and navigation

An approach to robot perception and world modeling that uses a probabilistic tesselated representation of spatial information called the occupancy grid is reviewed. The occupancy grid is a multidimensional random field that maintains stochastic estimates of the occupancy state of the cells in a spatial lattice. To construct a sensor-derived map of the robot's world, the cell state estimates are obtained by interpreting the incoming range readings using probabilistic sensor models. Bayesian estimation procedures allow the incremental updating of the occupancy grid, using readings taken from several sensors over multiple points of view. The use of occupancy grids from mapping and for navigation is examined. Operations on occupancy grids and extensions of the occupancy grid framework are briefly considered. >
Tau inhibits anterograde axonal transport and perturbs stability in growing axonal neurites in part by displacing kinesin cargo: neurofilaments attenuate tau-mediated neurite instability.

Overexpression of tau compromises axonal transport and induces retraction of growing neurites. We tested the hypothesis that increased stability provided by neurofilaments (NFs) may prevent axonal retraction. NB2a/d1 cells were differentiated for 3 days, at which time phosphorylated NFs appear and for 14 days, which induces continued neurite elongation and further phospho-NF accumulation. Cultures were transfected with a construct that expresses full-length, 4-repeat tau. Consistent with prior studies, overexpression of tau induced retraction of day three axonal neurites even following treatment with the microtubule-stabilizing drug taxol. Axonal neurites of day 14 cells were more resistant to tau-mediated retraction. To test whether or not this resistance was derived from their additional NF content, day 3 cultures were co-transfected with constructs expressing tau and NF-M (which increases overall axonal NFs). Overexpression of NF-M attenuated tau-mediated retraction of day 3 axonal neurites. By contrast, co-transfection with constructs expressing tau and vimentin (which increases axonal neurites length) did not attenuate tau-mediated neurite retraction. Co-precipitation experiments indicate that tau is a cargo of kinesin, and that tau overexpression may displace other kinesin-based cargo, including both critical cytoskeletal proteins and organelles. However, cultures simultaneously transfected with constructs expressing NF-M and tau, the level of examined vesicles was maintained. These collectively indicate that NFs stabilize developing axonal neurites and can counteract the destabilizing force resulting from overexpression of tau, and underscore that the development and stabilization of axonal neurites is dependent upon a balance of cytoskeletal elements. Cell Motil. Cytoskeleton 2007. © 2007 Wiley-Liss, Inc.