Studies of the hormonal control of postnatal testicular descent in the rat.

Science.gov (United States)

Spencer, J R; Vaughan, E D; Imperato-McGinley, J

1993-03-01

Dihydrotestosterone is believed to control the transinguinal phase of testicular descent based on hormonal manipulation studies performed in postnatal rats. In the present study, these hormonal manipulation experiments were repeated, and the results were compared with those obtained using the antiandrogens flutamide and cyproterone acetate. 17 beta-estradiol completely blocked testicular descent, but testosterone and dihydrotestosterone were equally effective in reversing this inhibition. Neither flutamide nor cyproterone acetate prevented testicular descent in postnatal rats despite marked peripheral antiandrogenic action. Further analysis of the data revealed a correlation between testicular size and descent. Androgen receptor blockade did not produce a marked reduction in testicular size and consequently did not prevent testicular descent, whereas estradiol alone caused marked testicular atrophy and testicular maldescent. Reduction of the estradiol dosage or concomitant administration of androgens or human chorionic gonadotropin resulted in both increased testicular size and degree of descent. These data suggest that growth of the neonatal rat testis may contribute to its passage into the scrotum.

Controlled time of arrival windows for already initiated energy-neutral continuous descent operations

OpenAIRE

Dalmau Codina, Ramon; Prats Menéndez, Xavier

2017-01-01

Continuous descent operations with controlled times of arrival at one or several metering fixes could enable environmentally friendly procedures without compromising terminal airspace capacity. This paper focuses on controlled time of arrival updates once the descent has been already initiated, assessing the feasible time window (and associated fuel consumption) of continuous descent operations requiring neither thrust nor speed-brake usage along the whole descent (i.e. only elevator control ...

Entry, Descent, and Landing With Propulsive Deceleration

Science.gov (United States)

Palaszewski, Bryan

2012-01-01

The future exploration of the Solar System will require innovations in transportation and the use of entry, descent, and landing (EDL) systems at many planetary landing sites. The cost of space missions has always been prohibitive, and using the natural planetary and planet s moons atmospheres for entry, descent, and landing can reduce the cost, mass, and complexity of these missions. This paper will describe some of the EDL ideas for planetary entry and survey the overall technologies for EDL that may be attractive for future Solar System missions.

Evolutionary analyses of non-genealogical bonds produced by introgressive descent.

Science.gov (United States)

Bapteste, Eric; Lopez, Philippe; Bouchard, Frédéric; Baquero, Fernando; McInerney, James O; Burian, Richard M

2012-11-06

All evolutionary biologists are familiar with evolutionary units that evolve by vertical descent in a tree-like fashion in single lineages. However, many other kinds of processes contribute to evolutionary diversity. In vertical descent, the genetic material of a particular evolutionary unit is propagated by replication inside its own lineage. In what we call introgressive descent, the genetic material of a particular evolutionary unit propagates into different host structures and is replicated within these host structures. Thus, introgressive descent generates a variety of evolutionary units and leaves recognizable patterns in resemblance networks. We characterize six kinds of evolutionary units, of which five involve mosaic lineages generated by introgressive descent. To facilitate detection of these units in resemblance networks, we introduce terminology based on two notions, P3s (subgraphs of three nodes: A, B, and C) and mosaic P3s, and suggest an apparatus for systematic detection of introgressive descent. Mosaic P3s correspond to a distinct type of evolutionary bond that is orthogonal to the bonds of kinship and genealogy usually examined by evolutionary biologists. We argue that recognition of these evolutionary bonds stimulates radical rethinking of key questions in evolutionary biology (e.g., the relations among evolutionary players in very early phases of evolutionary history, the origin and emergence of novelties, and the production of new lineages). This line of research will expand the study of biological complexity beyond the usual genealogical bonds, revealing additional sources of biodiversity. It provides an important step to a more realistic pluralist treatment of evolutionary complexity.

Enumerating set partitions according to the number of descents of ...

Indian Academy of Sciences (India)

) according to the number of descents of size or more, where ≥ 1 is fixed. An explicit expression in terms of Stirling numbers of the second kind may be given for the total number of such descents in all the members of (,). We also ...

Testicular descent: INSL3, testosterone, genes and the intrauterine milieu

DEFF Research Database (Denmark)

Bay, Katrine; Main, Katharina M; Toppari, Jorma

2011-01-01

Complete testicular descent is a sign of, and a prerequisite for, normal testicular function in adult life. The process of testis descent is dependent on gubernacular growth and reorganization, which is regulated by the Leydig cell hormones insulin-like peptide 3 (INSL3) and testosterone. Investi...

Steepest descent method implementation on unconstrained optimization problem using C++ program

Science.gov (United States)

Napitupulu, H.; Sukono; Mohd, I. Bin; Hidayat, Y.; Supian, S.

2018-03-01

Steepest Descent is known as the simplest gradient method. Recently, many researches are done to obtain the appropriate step size in order to reduce the objective function value progressively. In this paper, the properties of steepest descent method from literatures are reviewed together with advantages and disadvantages of each step size procedure. The development of steepest descent method due to its step size procedure is discussed. In order to test the performance of each step size, we run a steepest descent procedure in C++ program. We implemented it to unconstrained optimization test problem with two variables, then we compare the numerical results of each step size procedure. Based on the numerical experiment, we conclude the general computational features and weaknesses of each procedure in each case of problem.

Hazard avoidance via descent images for safe landing

Science.gov (United States)

Yan, Ruicheng; Cao, Zhiguo; Zhu, Lei; Fang, Zhiwen

2013-10-01

In planetary or lunar landing missions, hazard avoidance is critical for landing safety. Therefore, it is very important to correctly detect hazards and effectively find a safe landing area during the last stage of descent. In this paper, we propose a passive sensing based HDA (hazard detection and avoidance) approach via descent images to lower the landing risk. In hazard detection stage, a statistical probability model on the basis of the hazard similarity is adopted to evaluate the image and detect hazardous areas, so that a binary hazard image can be generated. Afterwards, a safety coefficient, which jointly utilized the proportion of hazards in the local region and the inside hazard distribution, is proposed to find potential regions with less hazards in the binary hazard image. By using the safety coefficient in a coarse-to-fine procedure and combining it with the local ISD (intensity standard deviation) measure, the safe landing area is determined. The algorithm is evaluated and verified with many simulated descent downward looking images rendered from lunar orbital satellite images.

THE GREAT DESCENT CONTINUES

CERN Document Server

    With precise coordination YE+1 was lowered into the cavern (9-Jan), soon joined by the ?rst barrel wheel YB+2 (19-Jan), then YB+1(4-Feb) and HB+ (13-Feb). The 1920 ton central barrel wheel YB0 rests brie?y on the pit-head cover in anticipation of a monumental descent (28-Feb) that will also trigger an intense campaign of installation of services and detectors underground.  

Propulsive Descent Technologies (PDT): Original Content Project

Data.gov (United States)

National Aeronautics and Space Administration — Future missions to Mars require landed mass that exceeds the capability of current entry, descent, and landing technology.  New technology and techniques are...

Dictionary descent in optimization

OpenAIRE

Temlyakov, Vladimir

2015-01-01

The problem of convex optimization is studied. Usually in convex optimization the minimization is over a d-dimensional domain. Very often the convergence rate of an optimization algorithm depends on the dimension d. The algorithms studied in this paper utilize dictionaries instead of a canonical basis used in the coordinate descent algorithms. We show how this approach allows us to reduce dimensionality of the problem. Also, we investigate which properties of a dictionary are beneficial for t...

Additive genetic variation in schizophrenia risk is shared by populations of African and European descent

NARCIS (Netherlands)

De Candia, T.r.; Lee, S.H.; Yang, J.; Browning, B.L.; Gejman, P. V.; Levinson, D. F.; Mowry, B. J.; Hewitt, J.K.; Goddard, M.E.; O'Donovan, M.C.; Purcell, S.M.; Posthuma, D.; Visscher, P. M.; Wray, N.R.; Keller, M. C.

2013-01-01

To investigate the extent to which the proportion of schizophrenia's additive genetic variation tagged by SNPs is shared by populations of European and African descent, we analyzed the largest combined African descent (AD [n = 2,142]) and European descent (ED [n = 4,990]) schizophrenia case-control

Analysis of foot clearance in firefighters during ascent and descent of stairs.

Science.gov (United States)

Kesler, Richard M; Horn, Gavin P; Rosengren, Karl S; Hsiao-Wecksler, Elizabeth T

2016-01-01

Slips, trips, and falls are a leading cause of injury to firefighters with many injuries occurring while traversing stairs, possibly exaggerated by acute fatigue from firefighting activities and/or asymmetric load carriage. This study examined the effects that fatigue, induced by simulated firefighting activities, and hose load carriage have on foot clearance while traversing stairs. Landing and passing foot clearances for each stair during ascent and descent of a short staircase were investigated. Clearances decreased significantly (p < 0.05) post-exercise for nine of 12 ascent parameters and increased for two of eight descent parameters. Load carriage resulted in significantly decreased (p < 0.05) clearance over three ascent parameters, and one increase during descent. Decreased clearances during ascent caused by fatigue or load carriage may result in an increased trip risk. Increased clearances during descent may suggest use of a compensation strategy to ensure stair clearance or an increased risk of over-stepping during descent. Copyright © 2015 Elsevier Ltd and The Ergonomics Society. All rights reserved.

Determination of accelerated factors in gradient descent iterations based on Taylor's series

Directory of Open Access Journals (Sweden)

Petrović Milena

2017-01-01

Full Text Available In this paper the efficiency of accelerated gradient descent methods regarding the way of determination of accelerated factor is considered. Due to the previous researches we assert that the use of Taylor's series of posed gradient descent iteration in calculation of accelerated parameter gives better final results than some other choices. We give a comparative analysis of efficiency of several methods with different approaches in obtaining accelerated parameter. According to the achieved results of numerical experiments we make a conclusion about the one of the most optimal way in defining accelerated parameter in accelerated gradient descent schemes.

Steepest descent approximations for accretive operator equations

International Nuclear Information System (INIS)

Chidume, C.E.

1993-03-01

A necessary and sufficient condition is established for the strong convergence of the steepest descent approximation to a solution of equations involving quasi-accretive operators defined on a uniformly smooth Banach space. (author). 49 refs

Ground reaction forces and frictional demands during stair descent: effects of age and illumination.

Science.gov (United States)

Christina, Kathryn A; Cavanagh, Peter R

2002-04-01

Stair descent is an inherently risky and demanding task that older adults often encounter in everyday life. It is believed that slip between the foot or shoe sole and the stair surface may play a role in stair related falls, however, there are no reports on slip resistance requirements for stair descent. The aim of this study was to determine the required coefficient of friction (RCOF) necessary for safe stair descent in 12 young and 12 older adults, under varied illuminance conditions. The RCOF during stair descent was found to be comparable in magnitude and time to that for overground walking, and thus, with adequate footwear and dry stair surfaces, friction does not appear to be a major determinant of stair safety. Illuminance level had little effect on the dependent variables quantified in this study. However, the older participants demonstrated safer strategies than the young during stair descent, as reflected by differences in the ground reaction forces and lower RCOF.

Inflammatory bowel disease in children of middle eastern descent.

Science.gov (United States)

Naidoo, Christina Mai Ying; Leach, Steven T; Day, Andrew S; Lemberg, Daniel A

2014-01-01

Increasing rates of inflammatory bowel disease (IBD) are now seen in populations where it was once uncommon. The pattern of IBD in children of Middle Eastern descent in Australia has never been reported. This study aimed to investigate the burden of IBD in children of Middle Eastern descent at the Sydney Children's Hospital, Randwick (SCHR). The SCHR IBD database was used to identify patients of self-reported Middle Eastern ethnicity diagnosed between 1987 and 2011. Demographic, diagnosis, and management data was collected for all Middle Eastern children and an age and gender matched non-Middle Eastern IBD control group. Twenty-four patients of Middle Eastern descent were identified. Middle Eastern Crohn's disease patients had higher disease activity at diagnosis, higher use of thiopurines, and less restricted colonic disease than controls. Although there were limitations with this dataset, we estimated a higher prevalence of IBD in Middle Eastern children and they had a different disease phenotype and behavior compared to the control group, with less disease restricted to the colon and likely a more active disease course.

Environmental effects on hormonal regulation of testicular descent

DEFF Research Database (Denmark)

Toppari, J; Virtanen, H E; Skakkebaek, N E

2006-01-01

cause some cases of undescended testis. Similarly, androgen insensitivity or androgen deficiency can cause cryptorchidism. Estrogens have been shown to down regulate INSL3 and thereby cause maldescent. Thus, a reduced androgen-estrogen ratio may disturb testicular descent. Environmental effects changing......Regulation of testicular descent is hormonally regulated, but the reasons for maldescent remain unknown in most cases. The main regulatory hormones are Leydig cell-derived testosterone and insulin-like factor 3 (INSL3). Luteinizing hormone (LH) stimulates the secretion of these hormones...... hypothesize that an exposure to a mixture of chemicals with anti-androgenic or estrogenic properties (either their own activity or their effect on androgen-estrogen ratio) may be involved in cryptorchidism....

Whole-body angular momentum during stair ascent and descent.

Science.gov (United States)

Silverman, Anne K; Neptune, Richard R; Sinitski, Emily H; Wilken, Jason M

2014-04-01

The generation of whole-body angular momentum is essential in many locomotor tasks and must be regulated in order to maintain dynamic balance. However, angular momentum has not been investigated during stair walking, which is an activity that presents a biomechanical challenge for balance-impaired populations. We investigated three-dimensional whole-body angular momentum during stair ascent and descent and compared it to level walking. Three-dimensional body-segment kinematic and ground reaction force (GRF) data were collected from 30 healthy subjects. Angular momentum was calculated using a 13-segment whole-body model. GRFs, external moment arms and net joint moments were used to interpret the angular momentum results. The range of frontal plane angular momentum was greater for stair ascent relative to level walking. In the transverse and sagittal planes, the range of angular momentum was smaller in stair ascent and descent relative to level walking. Significant differences were also found in the ground reaction forces, external moment arms and net joint moments. The sagittal plane angular momentum results suggest that individuals alter angular momentum to effectively counteract potential trips during stair ascent, and reduce the range of angular momentum to avoid falling forward during stair descent. Further, significant differences in joint moments suggest potential neuromuscular mechanisms that account for the differences in angular momentum between walking conditions. These results provide a baseline for comparison to impaired populations that have difficulty maintaining dynamic balance, particularly during stair ascent and descent. Copyright © 2014 Elsevier B.V. All rights reserved.

Descent construction for GSpin groups

CERN Document Server

Hundley, Joseph

2016-01-01

In this paper the authors provide an extension of the theory of descent of Ginzburg-Rallis-Soudry to the context of essentially self-dual representations, that is, representations which are isomorphic to the twist of their own contragredient by some Hecke character. The authors' theory supplements the recent work of Asgari-Shahidi on the functorial lift from (split and quasisplit forms of) GSpin_{2n} to GL_{2n}.

Convective descent simulations of drilling discharges on Georges and Sable Island banks

International Nuclear Information System (INIS)

Andrade, Y.; Loder, J.W.

1997-01-01

Factors affecting the fate of drilling mud discharges on Georges and Sable Island Banks were examined. The Koh and Chang jet discharge model was used to simulate the convective descent of a jet discharge of relatively dense materials at sites representing different hydrographic and depth regimes with a range of mud densities, and different discharge configurations, ocean currents and seasonal stratifications. The study revealed the dependence of the depth of descent and properties of the discharge plume on the discharge configuration and oceanographic conditions. The factors that affected the depth of descent were mud density, depth of release, initial downward volume flux of the discharge, current strength and ocean stratification. 22 refs., 3 tabs., 59 figs

Conjugate descent formulation of backpropagation error in ...

African Journals Online (AJOL)

The feedforward neural network architecture uses backpropagation learning to determine optimal weights between dierent interconnected layers. This learning procedure uses a gradient descent technique applied to a sum-of-squares error function for the given input-output pattern. It employs an iterative procedure to ...

Immediate effects of a distal gait modification during stair descent in individuals with patellofemoral pain.

Science.gov (United States)

Aliberti, Sandra; Mezêncio, Bruno; Amadio, Alberto Carlos; Serrão, Julio Cerca; Mochizuki, Luis

2018-05-23

Knee pain during stair managing is a common complaint among individuals with PFP and can negatively affect their activities of daily living. Gait modification programs can be used to decrease patellofemoral pain. Immediate effects of a stair descent distal gait modification session that intended to emphasize forefoot landing during stair descent are described in this study. To analyze the immediate effects of a distal gait modification session on lower extremity movements and intensity of pain in women with patellofemoral pain during stair descent. Nonrandomized controlled trial. Sixteen women with patellofemoral pain were allocated into two groups: (1) Gait Modification Group (n = 8); and 2) Control Group (n = 8). The intensity of pain (visual analog scale) and kinematics of knee, ankle, and forefoot (multi-segmental foot model) during stair descent were assessed before and after the intervention. After the gait modification session, there was an increase of forefoot eversion and ankle plantarflexion as well as a decrease of knee flexion. An immediate decrease in patellofemoral pain intensity during stair descent was also observed. The distal gait modification session changed the lower extremity kinetic chain strategy of movement, increasing foot and ankle movement contribution and decreasing knee contribution to the task. An immediate decrease in patellofemoral pain intensity during stair descent was also observed. To emphasize forefoot landing may be a useful intervention to immediately relieve pain in patients with patellofemoral pain during stair descent. Clinical studies are needed to verify the gait modification session effects in medium and long terms.

Ascent, descent, nullity, defect, and related notions for linear relations in linear spaces

NARCIS (Netherlands)

Sandovici, Adrian; de Snoo, Henk; Winkler, Henrik

2007-01-01

For a linear relation in a linear space the concepts of ascent, descent, nullity, and defect are introduced and studied. It is shown that the results of A.E. Taylor and M.A. Kaashoek concerning the relationship between ascent, descent, nullity, and defect for the case of linear operators remain

Ionospheric forecasting model using fuzzy logic-based gradient descent method

Directory of Open Access Journals (Sweden)

D. Venkata Ratnam

2017-09-01

Full Text Available Space weather phenomena cause satellite to ground or satellite to aircraft transmission outages over the VHF to L-band frequency range, particularly in the low latitude region. Global Positioning System (GPS is primarily susceptible to this form of space weather. Faulty GPS signals are attributed to ionospheric error, which is a function of Total Electron Content (TEC. Importantly, precise forecasts of space weather conditions and appropriate hazard observant cautions required for ionospheric space weather observations are limited. In this paper, a fuzzy logic-based gradient descent method has been proposed to forecast the ionospheric TEC values. In this technique, membership functions have been tuned based on the gradient descent estimated values. The proposed algorithm has been tested with the TEC data of two geomagnetic storms in the low latitude station of KL University, Guntur, India (16.44°N, 80.62°E. It has been found that the gradient descent method performs well and the predicted TEC values are close to the original TEC measurements.

Testicular descent: INSL3, testosterone, genes and the intrauterine milieu.

Science.gov (United States)

Bay, Katrine; Main, Katharina M; Toppari, Jorma; Skakkebæk, Niels E

2011-04-01

Complete testicular descent is a sign of, and a prerequisite for, normal testicular function in adult life. The process of testis descent is dependent on gubernacular growth and reorganization, which is regulated by the Leydig cell hormones insulin-like peptide 3 (INSL3) and testosterone. Investigation of the role of INSL3 and its receptor, relaxin-family peptide receptor 2 (RXFP2), has contributed substantially to our understanding of the hormonal control of testicular descent. Cryptorchidism is a common congenital malformation, which is seen in 2-9% of newborn boys, and confers an increased risk of infertility and testicular cancer in adulthood. Although some cases of isolated cryptorchidism in humans can be ascribed to known genetic defects, such as mutations in INSL3 or RXFP2, the cause of cryptorchidism remains unknown in most patients. Several animal and human studies are currently underway to test the hypothesis that in utero factors, including environmental and maternal lifestyle factors, may be involved in the etiology of cryptorchidism. Overall, the etiology of isolated cryptorchidism seems to be complex and multifactorial, involving both genetic and nongenetic components.

Impact of race on the professional lives of physicians of African descent.

Science.gov (United States)

Nunez-Smith, Marcella; Curry, Leslie A; Bigby, JudyAnn; Berg, David; Krumholz, Harlan M; Bradley, Elizabeth H

2007-01-02

Increasing the racial and ethnic diversity of the physician workforce is a national priority. However, insight into the professional experiences of minority physicians is limited. This knowledge is fundamental to developing effective strategies to recruit, retain, and support a diverse physician workforce. To characterize how physicians of African descent experience race in the workplace. Qualitative study based on in-person and in-depth racially concordant interviews using a standard discussion guide. The 6 New England states in the United States. 25 practicing physicians of African descent representing a diverse range of primary practice settings, specialties, and ages. Professional experiences of physicians of African descent. 1) Awareness of race permeates the experience of physicians of African descent in the health care workplace; 2) race-related experiences shape interpersonal interactions and define the institutional climate; 3) responses to perceived racism at work vary along a spectrum from minimization to confrontation; 4) the health care workplace is often silent on issues of race; and 5) collective race-related experiences can result in "racial fatigue," with personal and professional consequences for physicians. The study was restricted to New England and may not reflect the experiences of physicians in other geographic regions. The findings are meant to be hypothesis-generating and require additional follow-up studies. The issue of race remains a pervasive influence in the work lives of physicians of African descent. Without sufficient attention to the specific ways in which race shapes physicians' work experiences, health care organizations are unlikely to create environments that successfully foster and sustain a diverse physician workforce.

Counseling and Psychotherapy with Clients of Middle Eastern Descent: A Qualitative Inquiry

OpenAIRE

Boghosian, Sara

2011-01-01

It is becoming increasingly important for clinical and counseling psychologists to have multicultural competence skills for treating an increasingly diverse client population. The psychology literature related to culturally competent treatment with persons of Middle Eastern descent is currently limited. In this study, qualitative methodology was utilized to explore the mental health attitudes and psychotherapy experiences of clients of Middle Eastern descent. Participants described culturally...

Entry, Descent and Landing Systems Analysis Study: Phase 1 Report

Science.gov (United States)

DwyerCianciolo, Alicia M.; Davis, Jody L.; Komar, David R.; Munk, Michelle M.; Samareh, Jamshid A.; Powell, Richard W.; Shidner, Jeremy D.; Stanley, Douglas O.; Wilhite, Alan W.; Kinney, David J.;

Gradient descent learning algorithm overview: a general dynamical systems perspective.

Science.gov (United States)

Baldi, P

1995-01-01

Gives a unified treatment of gradient descent learning algorithms for neural networks using a general framework of dynamical systems. This general approach organizes and simplifies all the known algorithms and results which have been originally derived for different problems (fixed point/trajectory learning), for different models (discrete/continuous), for different architectures (forward/recurrent), and using different techniques (backpropagation, variational calculus, adjoint methods, etc.). The general approach can also be applied to derive new algorithms. The author then briefly examines some of the complexity issues and limitations intrinsic to gradient descent learning. Throughout the paper, the author focuses on the problem of trajectory learning.

Global Patterns of Prostate Cancer Incidence, Aggressiveness, and Mortality in Men of African Descent

Directory of Open Access Journals (Sweden)

Timothy R. Rebbeck

2013-01-01

Full Text Available Prostate cancer (CaP is the leading cancer among men of African descent in the USA, Caribbean, and Sub-Saharan Africa (SSA. The estimated number of CaP deaths in SSA during 2008 was more than five times that among African Americans and is expected to double in Africa by 2030. We summarize publicly available CaP data and collected data from the men of African descent and Carcinoma of the Prostate (MADCaP Consortium and the African Caribbean Cancer Consortium (AC3 to evaluate CaP incidence and mortality in men of African descent worldwide. CaP incidence and mortality are highest in men of African descent in the USA and the Caribbean. Tumor stage and grade were highest in SSA. We report a higher proportion of T1 stage prostate tumors in countries with greater percent gross domestic product spent on health care and physicians per 100,000 persons. We also observed that regions with a higher proportion of advanced tumors reported lower mortality rates. This finding suggests that CaP is underdiagnosed and/or underreported in SSA men. Nonetheless, CaP incidence and mortality represent a significant public health problem in men of African descent around the world.

Corrugated thimble tube for controlling control rod descent in nuclear reactor

International Nuclear Information System (INIS)

Luetzow, H.J.

1981-01-01

A thimble tube construction is described which will provide a controlled descent for a control rod while minimizing the reaction forces which must be absorbed by the thimble tube and reducing the possibility that a foreign particle could interfere with the free descent of a control rod. A thimble tube is formed with helically-corrugate internal walls which cooperate with a control rod contained in the tube in an emergency situation to provide a progressively-increasing hydraulic restraining force as each adjacent corrugation is encountered

Practical gradient-descent for memristive crossbars

OpenAIRE

Nair, Manu V; Dudek, Piotr

2015-01-01

This paper discusses implementations of gradientdescent based learning algorithms on memristive crossbar arrays. The Unregulated Step Descent (USD) is described as a practical algorithm for feed-forward on-line training of large crossbar arrays. It allows fast feed-forward fully parallel on-line hardware based learning, without requiring accurate models of the memristor behaviour and precise control of the programming pulses. The effect of device parameters, training parameters, and device va...

Minimizing convex functions by continuous descent methods

Directory of Open Access Journals (Sweden)

Sergiu Aizicovici

2010-01-01

Full Text Available We study continuous descent methods for minimizing convex functions, defined on general Banach spaces, which are associated with an appropriate complete metric space of vector fields. We show that there exists an everywhere dense open set in this space of vector fields such that each of its elements generates strongly convergent trajectories.

The grand descent has begun for CMS

CERN Multimedia

2006-01-01

Until recently, the CMS experimental cavern looked relatively empty; its detector was assembled entirely at ground level, to be lowered underground in 15 sections. On 2 November, the first hadronic forward calorimeter led the way with a grand descent. The first section of the CMS detector (centre of photo) arriving from the vertical shaft, viewed from the cavern floor. There is something unusual about the construction of the CMS detector. Instead of being built in the experimental cavern, like all the other detectors in the LHC experiments, it was constructed at ground level. This was to allow for easy access during the assembly of the detector and to minimise the size of the excavated cavern. The slightly nerve-wracking task of lowering it safely into the cavern in separate sections came after the complete detector was successfully tested with a magnetic field at ground level. In the early morning of 2 November, the first section of the CMS detector began its eagerly awaited descent into the underground ca...

Planning fuel-conservative descents in an airline environmental using a small programmable calculator: algorithm development and flight test results

Energy Technology Data Exchange (ETDEWEB)

Knox, C.E.; Vicroy, D.D.; Simmon, D.A.

1985-05-01

A simple, airborne, flight-management descent algorithm was developed and programmed into a small programmable calculator. The algorithm may be operated in either a time mode or speed mode. The time mode was designed to aid the pilot in planning and executing a fuel-conservative descent to arrive at a metering fix at a time designated by the air traffic control system. The speed model was designed for planning fuel-conservative descents when time is not a consideration. The descent path for both modes was calculated for a constant with considerations given for the descent Mach/airspeed schedule, gross weight, wind, wind gradient, and nonstandard temperature effects. Flight tests, using the algorithm on the programmable calculator, showed that the open-loop guidance could be useful to airline flight crews for planning and executing fuel-conservative descents.

Ethnic Identity and Acculturative Stress as Mediators of Depression in Students of Asian Descent

Science.gov (United States)

Lantrip, Crystal; Mazzetti, Francesco; Grasso, Joseph; Gill, Sara; Miller, Janna; Haner, Morgynn; Rude, Stephanie; Awad, Germine

2015-01-01

This study underscored the importance of addressing the well-being of college students of Asian descent, because these students had higher rates of depression and lower positive feelings about their ethnic group compared with students of European descent, as measured by the Affirmation subscale of the Ethnic Identity Scale. Affirmation mediated…

Random versus Deterministic Descent in RNA Energy Landscape Analysis

Directory of Open Access Journals (Sweden)

Luke Day

2016-01-01

Full Text Available Identifying sets of metastable conformations is a major research topic in RNA energy landscape analysis, and recently several methods have been proposed for finding local minima in landscapes spawned by RNA secondary structures. An important and time-critical component of such methods is steepest, or gradient, descent in attraction basins of local minima. We analyse the speed-up achievable by randomised descent in attraction basins in the context of large sample sets where the size has an order of magnitude in the region of ~106. While the gain for each individual sample might be marginal, the overall run-time improvement can be significant. Moreover, for the two nongradient methods we analysed for partial energy landscapes induced by ten different RNA sequences, we obtained that the number of observed local minima is on average larger by 7.3% and 3.5%, respectively. The run-time improvement is approximately 16.6% and 6.8% on average over the ten partial energy landscapes. For the large sample size we selected for descent procedures, the coverage of local minima is very high up to energy values of the region where the samples were randomly selected from the partial energy landscapes; that is, the difference to the total set of local minima is mainly due to the upper area of the energy landscapes.

Videodefaecography combined with measurement of the anorectal angle and of perineal descent

International Nuclear Information System (INIS)

Skomorowska, E.; Henrichsen, S.; Christiansen, J.; Hegedues, V.; Glostrup Sygehus, Copenhagen

1987-01-01

Cineradiographic defaecography combined with measurement of the anorectal angle and descent of the pelvic floor is proposed. The method used in 73 women gave valuable information in 48 patients who complained of anal incompetence, rectal tenesmus, and chronic constipation. In these patients, high and low rectal intussusception, rectocele, and pathologic movement of the pelvic floor were detected. Some of these phenomena could only be diagnosed by the radiologic method here described. Quantitations of the anorectal angle and descent of the pelvic floor placed the group with constipation halfway between normal individuals and those with anal incompetence. The value of this finding is discussed. Recent improvements in anorectal surgery often make videodefaecography decisive for the choice of the optimal operative method. Therefore, videodefaecography together with measurement of the anorectal angle and pelvic floor descent is recommended whenever anorectal surgery for correction of functional disturbances is contemplated. (orig.)

Conjugate descent formulation of backpropagation error in feedforward neural networks

Directory of Open Access Journals (Sweden)

NK Sharma

2009-06-01

Full Text Available The feedforward neural network architecture uses backpropagation learning to determine optimal weights between different interconnected layers. This learning procedure uses a gradient descent technique applied to a sum-of-squares error function for the given input-output pattern. It employs an iterative procedure to minimise the error function for a given set of patterns, by adjusting the weights of the network. The first derivates of the error with respect to the weights identify the local error surface in the descent direction. Hence the network exhibits a different local error surface for every different pattern presented to it, and weights are iteratively modified in order to minimise the current local error. The determination of an optimal weight vector is possible only when the total minimum error (mean of the minimum local errors for all patterns from the training set may be minimised. In this paper, we present a general mathematical formulation for the second derivative of the error function with respect to the weights (which represents a conjugate descent for arbitrary feedforward neural network topologies, and we use this derivative information to obtain the optimal weight vector. The local error is backpropagated among the units of hidden layers via the second order derivative of the error with respect to the weights of the hidden and output layers independently and also in combination. The new total minimum error point may be evaluated with the help of the current total minimum error and the current minimised local error. The weight modification processes is performed twice: once with respect to the present local error and once more with respect to the current total or mean error. We present some numerical evidence that our proposed method yields better network weights than those determined via a conventional gradient descent approach.

Three-dimensional sparse electromagnetic imaging accelerated by projected steepest descent

KAUST Repository

Desmal, Abdulla

2016-11-02

An efficient and accurate scheme for solving the nonlinear electromagnetic inverse scattering problem on three-dimensional sparse investigation domains is proposed. The minimization problem is constructed in such a way that the data misfit between measurements and scattered fields (which are expressed as a nonlinear function of the contrast) is constrained by the contrast\\'s first norm. The resulting minimization problem is solved using nonlinear Landweber iterations accelerated using a steepest descent algorithm. A projection operator is applied at every iteration to enforce the sparsity constraint by thresholding the result of that iteration. Steepest descent algorithm ensures accelerated and convergent solution by utilizing larger iteration steps selected based on a necessary B-condition.

Efficient Sensor Placement Optimization Using Gradient Descent and Probabilistic Coverage

Directory of Open Access Journals (Sweden)

Vahab Akbarzadeh

2014-08-01

Full Text Available We are proposing an adaptation of the gradient descent method to optimize the position and orientation of sensors for the sensor placement problem. The novelty of the proposed method lies in the combination of gradient descent optimization with a realistic model, which considers both the topography of the environment and a set of sensors with directional probabilistic sensing. The performance of this approach is compared with two other black box optimization methods over area coverage and processing time. Results show that our proposed method produces competitive results on smaller maps and superior results on larger maps, while requiring much less computation than the other optimization methods to which it has been compared.

Entry, Descent, and Landing for Human Mars Missions

Science.gov (United States)

Munk, Michelle M.; DwyerCianciolo, Alicia M.

2012-01-01

One of the most challenging aspects of a human mission to Mars is landing safely on the Martian surface. Mars has such low atmospheric density that decelerating large masses (tens of metric tons) requires methods that have not yet been demonstrated, and are not yet planned in future Mars missions. To identify the most promising options for Mars entry, descent, and landing, and to plan development of the needed technologies, NASA's Human Architecture Team (HAT) has refined candidate methods for emplacing needed elements of the human Mars exploration architecture (such as ascent vehicles and habitats) on the Mars surface. This paper explains the detailed, optimized simulations that have been developed to define the mass needed at Mars arrival to accomplish the entry, descent, and landing functions. Based on previous work, technology options for hypersonic deceleration include rigid, mid-L/D (lift-to-drag ratio) aeroshells, and inflatable aerodynamic decelerators (IADs). The hypersonic IADs, or HIADs, are about 20% less massive than the rigid vehicles, but both have their technology development challenges. For the supersonic regime, supersonic retropropulsion (SRP) is an attractive option, since a propulsive stage must be carried for terminal descent and can be ignited at higher speeds. The use of SRP eliminates the need for an additional deceleration system, but SRP is at a low Technology Readiness Level (TRL) in that the interacting plumes are not well-characterized, and their effect on vehicle stability has not been studied, to date. These architecture-level assessments have been used to define the key performance parameters and a technology development strategy for achieving the challenging mission of landing large payloads on Mars.

Correlation Between Echodefecography and 3-Dimensional Vaginal Ultrasonography in the Detection of Perineal Descent in Women With Constipation Symptoms.

Science.gov (United States)

Murad-Regadas, Sthela M; Pinheiro Regadas, Francisco Sergio; Rodrigues, Lusmar V; da Silva Vilarinho, Adjra; Buchen, Guilherme; Borges, Livia Olinda; Veras, Lara B; da Cruz, Mariana Murad

2016-12-01

Defecography is an established method of evaluating dynamic anorectal dysfunction, but conventional defecography does not allow for visualization of anatomic structures. The purpose of this study was to describe the use of dynamic 3-dimensional endovaginal ultrasonography for evaluating perineal descent in comparison with echodefecography (3-dimensional anorectal ultrasonography) and to study the relationship between perineal descent and symptoms and anatomic/functional abnormalities of the pelvic floor. This was a prospective study. The study was conducted at a large university tertiary care hospital. Consecutive female patients were eligible if they had pelvic floor dysfunction, obstructed defecation symptoms, and a score >6 on the Cleveland Clinic Florida Constipation Scale. Each patient underwent both echodefecography and dynamic 3-dimensional endovaginal ultrasonography to evaluate posterior pelvic floor dysfunction. Normal perineal descent was defined on echodefecography as puborectalis muscle displacement ≤2.5 cm; excessive perineal descent was defined as displacement >2.5 cm. Of 61 women, 29 (48%) had normal perineal descent; 32 (52%) had excessive perineal descent. Endovaginal ultrasonography identified 27 of the 29 patients in the normal group as having anorectal junction displacement ≤1 cm (mean = 0.6 cm; range, 0.1-1.0 cm) and a mean anorectal junction position of 0.6 cm (range, 0-2.3 cm) above the symphysis pubis during the Valsalva maneuver and correctly identified 30 of the 32 patients in the excessive perineal descent group. The κ statistic showed almost perfect agreement (κ = 0.86) between the 2 methods for categorization into the normal and excessive perineal descent groups. Perineal descent was not related to fecal or urinary incontinence or anatomic and functional factors (sphincter defects, pubovisceral muscle defects, levator hiatus area, grade II or III rectocele, intussusception, or anismus). The study did not include a

Descent in buildings (AM-190)

CERN Document Server

Mühlherr, Bernhard; Weiss, Richard M

2015-01-01

Descent in Buildings begins with the resolution of a major open question about the local structure of Bruhat-Tits buildings. The authors then put their algebraic solution into a geometric context by developing a general fixed point theory for groups acting on buildings of arbitrary type, giving necessary and sufficient conditions for the residues fixed by a group to form a kind of subbuilding or "form" of the original building. At the center of this theory is the notion of a Tits index, a combinatorial version of the notion of an index in the relative theory of algebraic groups. These results

RITD - Adapting Mars Entry, Descent and Landing System for Earth

Science.gov (United States)

Haukka, H.; Heilimo, J.; Harri, A.-M.; Aleksashkin, S.; Koryanov, V.; Arruego, I.; Schmidt, W.; Finchenko, V.; Martynov, M.; Ponomarenko, A.; Kazakovtsev, V.; Martin, S.

2015-10-01

We have developed an atmospheric re-entry and descent system concept based on inflatable hypersonic decelerator techniques that were originally developed for Mars. The ultimate goal of this EU-funded RITD-project (Re-entry: Inflatable Technology Development) was to assess the benefits of this technology when deploying small payloads from low Earth orbits to the surface of the Earth with modest costs. The principal goal was to assess and develop a preliminary EDLS design for the entire relevant range of aerodynamic regimes expected to be encountered in Earth's atmosphere during entry, descent and landing. Low Earth Orbit (LEO) and even Lunar applications envisaged include the use of the EDLS approach in returning payloads of 4-8 kg down to the surface.

Reversible cerebral vasoconstriction syndrome precipitated by airplane descent: Case report.

Science.gov (United States)

Hiraga, Akiyuki; Aotsuka, Yuya; Koide, Kyosuke; Kuwabara, Satoshi

2017-10-01

Background Reversible cerebral vasoconstriction syndrome (RCVS) is characterized by segmental vasospasm. Vasoactive agents and childbirth have been reported as precipitating factors for RCVS; however, RCVS induced by altitude change or air travel has rarely been reported. Case We present a case of a 74-year-old woman who presented with thunderclap headache during airplane descent. Magnetic resonance angiography demonstrated segmental vasoconstriction that improved 9 days after onset. Conclusion These findings indicate that airplane descent may be a trigger of RCVS. The time course of headache in the present case was similar to that of prolonged headache attributed to airplane travel, indicating that RCVS during air travel may have previously been overlooked and that some headache attributed to airplane travel cases may represent a milder form of RCVS.

Entry, Descent and Landing Systems Analysis: Exploration Class Simulation Overview and Results

Science.gov (United States)

DwyerCianciolo, Alicia M.; Davis, Jody L.; Shidner, Jeremy D.; Powell, Richard W.

2010-01-01

NASA senior management commissioned the Entry, Descent and Landing Systems Analysis (EDL-SA) Study in 2008 to identify and roadmap the Entry, Descent and Landing (EDL) technology investments that the agency needed to make in order to successfully land large payloads at Mars for both robotic and exploration or human-scale missions. The year one exploration class mission activity considered technologies capable of delivering a 40-mt payload. This paper provides an overview of the exploration class mission study, including technologies considered, models developed and initial simulation results from the EDL-SA year one effort.

Nonlinear System Identification Using Neural Networks Trained with Natural Gradient Descent

Directory of Open Access Journals (Sweden)

Ibnkahla Mohamed

2003-01-01

Full Text Available We use natural gradient (NG learning neural networks (NNs for modeling and identifying nonlinear systems with memory. The nonlinear system is comprised of a discrete-time linear filter followed by a zero-memory nonlinearity . The NN model is composed of a linear adaptive filter followed by a two-layer memoryless nonlinear NN. A Kalman filter-based technique and a search-and-converge method have been employed for the NG algorithm. It is shown that the NG descent learning significantly outperforms the ordinary gradient descent and the Levenberg-Marquardt (LM procedure in terms of convergence speed and mean squared error (MSE performance.

Gender differences of sagittal knee and ankle biomechanics during stair-to-ground descent transition.

Science.gov (United States)

Hong, Yoon No Gregory; Shin, Choongsoo S

2015-12-01

Falls on stairs often result in severe injury and occur twice as frequently in women. However, gender differences in kinetics and kinematics during stair descent are unknown. Thus, this study aimed to determine whether gender differences of knee and ankle biomechanics exist in the sagittal plane during the stair-to-ground descending transition. It was hypothesized that 1) women would reveal higher ground-toe-trochanter angle and lower ground-toe length during stair-to-ground descent transition than men; and 2) women would reveal lower peak knee extension moment during stair-to-ground descent transition than men. Fifteen men and fifteen women were recruited and performed a stair descent activity. Kinetic and kinematic data were obtained using a force plate and motion capture system. The women performed the stair descent with a lower peak knee extension moment and a peak knee power at the early weight acceptance phase. The women also revealed a higher ground-toe-trochanter angle and a lower ground-toe length, which indicated a more forward position of the lower extremity relative to the toe contact point at both the initial contact and at the time of peak kinematic and kinetic events. This study found that knee and ankle kinematics and kinetics differed significantly between the genders due to differences in ground-toe-trochanter angle. Women have a different stair descending strategy that reduces the demand of the lower extremity muscle function, but this strategy seems to increase the risk of falls. Copyright © 2015 Elsevier Ltd. All rights reserved.

Reference-shaping adaptive control by using gradient descent optimizers.

Directory of Open Access Journals (Sweden)

Baris Baykant Alagoz

Full Text Available This study presents a model reference adaptive control scheme based on reference-shaping approach. The proposed adaptive control structure includes two optimizer processes that perform gradient descent optimization. The first process is the control optimizer that generates appropriate control signal for tracking of the controlled system output to a reference model output. The second process is the adaptation optimizer that performs for estimation of a time-varying adaptation gain, and it contributes to improvement of control signal generation. Numerical update equations derived for adaptation gain and control signal perform gradient descent optimization in order to decrease the model mismatch errors. To reduce noise sensitivity of the system, a dead zone rule is applied to the adaptation process. Simulation examples show the performance of the proposed Reference-Shaping Adaptive Control (RSAC method for several test scenarios. An experimental study demonstrates application of method for rotor control.

Real-time aircraft continuous descent trajectory optimization with ATC time constraints using direct collocation methods.

OpenAIRE

Verhoeven, Ronald; Dalmau Codina, Ramon; Prats Menéndez, Xavier; de Gelder, Nico

2014-01-01

1 Abstract In this paper an initial implementation of a real - time aircraft trajectory optimization algorithm is presented . The aircraft trajectory for descent and approach is computed for minimum use of thrust and speed brake in support of a “green” continuous descent and approach flight operation, while complying with ATC time constraints for maintaining runway throughput and co...

Machado-Joseph Disease in Pedigrees of Azorean descent is Linked to Chromosome 14

OpenAIRE

George-Hyslop, P. St; Rogaeva, E.; Huterer, J.; Tsuda, T.; Santos, J.; Haines, J. L.; Schlumpf, K.; Rogaev, E. I.; Liang, Y.; McLachlan, D. R. Crapper; Kennedy, J.; Weissenbach, J.; Billingsley, G. D.; Cox, D. W.; Lang, A. E.

1994-01-01

A locus for Machado-Joseph disease (MJD) has recently been mapped to a 30-cM region of chromosome 14q in five pedigrees of Japanese descent. MJD is a clinically pleomorphic neurodegenerative disease that was originally described in subjects of Azorean descent. In light of the nonallelic heterogeneity in other inherited spinocere-bellar ataxias, we were interested to determine if the MJD phenotype in Japanese and Azorean pedigrees arose from mutations at the same locus. We provide evidence tha...

Preconditioned stochastic gradient descent optimisation for monomodal image registration

NARCIS (Netherlands)

Klein, S.; Staring, M.; Andersson, J.P.; Pluim, J.P.W.; Fichtinger, G.; Martel, A.; Peters, T.

2011-01-01

We present a stochastic optimisation method for intensity-based monomodal image registration. The method is based on a Robbins-Monro stochastic gradient descent method with adaptive step size estimation, and adds a preconditioning matrix. The derivation of the pre-conditioner is based on the

Sparse Nonlinear Electromagnetic Imaging Accelerated With Projected Steepest Descent Algorithm

KAUST Repository

Desmal, Abdulla; Bagci, Hakan

2017-01-01

steepest descent algorithm. The algorithm uses a projection operator to enforce the sparsity constraint by thresholding the solution at every iteration. Thresholding level and iteration step are selected carefully to increase the efficiency without

Gradient descent for robust kernel-based regression

Science.gov (United States)

Guo, Zheng-Chu; Hu, Ting; Shi, Lei

2018-06-01

In this paper, we study the gradient descent algorithm generated by a robust loss function over a reproducing kernel Hilbert space (RKHS). The loss function is defined by a windowing function G and a scale parameter σ, which can include a wide range of commonly used robust losses for regression. There is still a gap between theoretical analysis and optimization process of empirical risk minimization based on loss: the estimator needs to be global optimal in the theoretical analysis while the optimization method can not ensure the global optimality of its solutions. In this paper, we aim to fill this gap by developing a novel theoretical analysis on the performance of estimators generated by the gradient descent algorithm. We demonstrate that with an appropriately chosen scale parameter σ, the gradient update with early stopping rules can approximate the regression function. Our elegant error analysis can lead to convergence in the standard L 2 norm and the strong RKHS norm, both of which are optimal in the mini-max sense. We show that the scale parameter σ plays an important role in providing robustness as well as fast convergence. The numerical experiments implemented on synthetic examples and real data set also support our theoretical results.

Is prenatal urethral descent a risk factor for urinary incontinence during pregnancy and the postpartum period?

Science.gov (United States)

Pizzoferrato, Anne-Cécile; Fauconnier, Arnaud; Bader, Georges; de Tayrac, Renaud; Fort, Julie; Fritel, Xavier

2016-07-01

Obstetric trauma during childbirth is considered a major risk factor for postpartum urinary incontinence (UI), particularly stress urinary incontinence. Our aim was to investigate the relation between postpartum UI, mode of delivery, and urethral descent, and to define a group of women who are particularly at risk of postnatal UI. A total of 186 women were included their first pregnancy. Validated questionnaires about urinary symptoms during pregnancy, 2 and 12 months after delivery, were administered. Urethral descent was assessed clinically and by ultrasound at inclusion. Multivariate logistic regression analysis was used to determine the risk factors for UI during pregnancy, at 2 months and 1 year after first delivery. The prevalence of UI was 38.6, 46.5, 35.6, and 34.4 % at inclusion, late pregnancy, 2 months postpartum, and 1 year postpartum respectively. No significant association was found between UI at late pregnancy and urethral descent assessed clinically or by ultrasound. The only risk factor for UI at 2 months postpartum was UI at inclusion (OR 6.27 [95 % CI 2.70-14.6]). The risk factors for UI at 1 year postpartum were UI at inclusion (6.14 [2.22-16.9]), body mass index (BMI), and urethral descent at inclusion, assessed clinically (7.21 [2.20-23.7]) or by ultrasound. The mode of delivery was not associated with urethral descent. Prenatal urethral descent and UI during pregnancy are risk factors for UI at 1 year postpartum. These results indicate that postnatal UI is more strongly influenced by susceptibility factors existing before first delivery than by the mode of delivery.

Local flow management/profile descent algorithm. Fuel-efficient, time-controlled profiles for the NASA TSRV airplane

Science.gov (United States)

Groce, J. L.; Izumi, K. H.; Markham, C. H.; Schwab, R. W.; Thompson, J. L.

1986-01-01

The Local Flow Management/Profile Descent (LFM/PD) algorithm designed for the NASA Transport System Research Vehicle program is described. The algorithm provides fuel-efficient altitude and airspeed profiles consistent with ATC restrictions in a time-based metering environment over a fixed ground track. The model design constraints include accommodation of both published profile descent procedures and unpublished profile descents, incorporation of fuel efficiency as a flight profile criterion, operation within the performance capabilities of the Boeing 737-100 airplane with JT8D-7 engines, and conformity to standard air traffic navigation and control procedures. Holding and path stretching capabilities are included for long delay situations.

Screening for homozygosity by descent in families with autosomal

Indian Academy of Sciences (India)

Home; Journals; Journal of Genetics; Volume 81; Issue 2 ... Perspectives Volume 81 Issue 2 August 2002 pp 59-63 ... disease locus in families with the recessive form of the disease, we used the approach of screening for homozygosity by descent in offspring of consanguineous and nonconsanguineous families with RP.

Airborne Management of Traffic Conflicts in Descent With Arrival Constraints

Science.gov (United States)

Doble, Nathan A.; Barhydt, Richard; Krishnamurthy, Karthik

2005-01-01

NASA is studying far-term air traffic management concepts that may increase operational efficiency through a redistribution of decisionmaking authority among airborne and ground-based elements of the air transportation system. One component of this research, En Route Free Maneuvering, allows trained pilots of equipped autonomous aircraft to assume responsibility for traffic separation. Ground-based air traffic controllers would continue to separate traffic unequipped for autonomous operations and would issue flow management constraints to all aircraft. To evaluate En Route Free Maneuvering operations, a human-in-the-loop experiment was jointly conducted by the NASA Ames and Langley Research Centers. In this experiment, test subject pilots used desktop flight simulators to resolve conflicts in cruise and descent, and to adhere to air traffic flow constraints issued by test subject controllers. Simulators at NASA Langley were equipped with a prototype Autonomous Operations Planner (AOP) flight deck toolset to assist pilots with conflict management and constraint compliance tasks. Results from the experiment are presented, focusing specifically on operations during the initial descent into the terminal area. Airborne conflict resolution performance in descent, conformance to traffic flow management constraints, and the effects of conflicting traffic on constraint conformance are all presented. Subjective data from subject pilots are also presented, showing perceived levels of workload, safety, and acceptability of autonomous arrival operations. Finally, potential AOP functionality enhancements are discussed along with suggestions to improve arrival procedures.

Intelligent Data Understanding for Architecture Analysis of Entry, Descent, and Landing

Data.gov (United States)

National Aeronautics and Space Administration — Because Entry, Descent and Landing (EDL) system validations are limited in Earth environments, these technologies rely heavily on models and analysis tools to...

The Role of la Familia for Women of Mexican Descent Who Are Leaders in Higher Education

Science.gov (United States)

Elizondo, Sandra Gray

2012-01-01

The purpose of this qualitative case study was to describe the role of "la familia" for women of Mexican descent as it relates to their development as leaders and their leadership in academia. Purposeful sampling was utilized to reach the goal of 18 participants who were female academic leaders of Mexican descent teaching full time in…

A Wind Tunnel Study on the Mars Pathfinder (MPF) Lander Descent Pressure Sensor

Science.gov (United States)

Soriano, J. Francisco; Coquilla, Rachael V.; Wilson, Gregory R.; Seiff, Alvin; Rivell, Tomas

2001-01-01

The primary focus of this study was to determine the accuracy of the Mars Pathfinder lander local pressure readings in accordance with the actual ambient atmospheric pressures of Mars during parachute descent. In order to obtain good measurements, the plane of the lander pressure sensor opening should ideally be situated so that it is parallel to the freestream. However, due to two unfavorable conditions, the sensor was positioned in locations where correction factors are required. One of these disadvantages is due to the fact that the parachute attachment point rotated the lander's center of gravity forcing the location of the pressure sensor opening to be off tangent to the freestream. The second and most troublesome factor was that the lander descends with slight oscillations that could vary the amplitude of the sensor readings. In order to accurately map the correction factors required at each sensor position, an experiment simulating the lander descent was conducted in the Martian Surface Wind Tunnel at NASA Ames Research Center. Using a 115 scale model at Earth ambient pressures, the test settings provided the necessary Reynolds number conditions in which the actual lander was possibly subjected to during the descent. In the analysis and results of this experiment, the readings from the lander sensor were converted to the form of pressure coefficients. With a contour map of pressure coefficients at each lander oscillatory position, this report will provide a guideline to determine the correction factors required for the Mars Pathfinder lander descent pressure sensor readings.

Non-homogeneous updates for the iterative coordinate descent algorithm

Science.gov (United States)

Yu, Zhou; Thibault, Jean-Baptiste; Bouman, Charles A.; Sauer, Ken D.; Hsieh, Jiang

2007-02-01

Statistical reconstruction methods show great promise for improving resolution, and reducing noise and artifacts in helical X-ray CT. In fact, statistical reconstruction seems to be particularly valuable in maintaining reconstructed image quality when the dosage is low and the noise is therefore high. However, high computational cost and long reconstruction times remain as a barrier to the use of statistical reconstruction in practical applications. Among the various iterative methods that have been studied for statistical reconstruction, iterative coordinate descent (ICD) has been found to have relatively low overall computational requirements due to its fast convergence. This paper presents a novel method for further speeding the convergence of the ICD algorithm, and therefore reducing the overall reconstruction time for statistical reconstruction. The method, which we call nonhomogeneous iterative coordinate descent (NH-ICD) uses spatially non-homogeneous updates to speed convergence by focusing computation where it is most needed. Experimental results with real data indicate that the method speeds reconstruction by roughly a factor of two for typical 3D multi-slice geometries.

Steepest descent moment method for three-dimensional magnetohydrodynamic equilibria

International Nuclear Information System (INIS)

Hirshman, S.P.; Whitson, J.C.

1983-11-01

An energy principle is used to obtain the solution of the magnetohydrodynamic (MHD) equilibrium equation J Vector x B Vector - del p = 0 for nested magnetic flux surfaces that are expressed in the inverse coordinate representation x Vector = x Vector(rho, theta, zeta). Here, theta and zeta are poloidal and toroidal flux coordinate angles, respectively, and p = p(rho) labels a magnetic surface. Ordinary differential equations in rho are obtained for the Fourier amplitudes (moments) in the doubly periodic spectral decomposition of x Vector. A steepest descent iteration is developed for efficiently solving these nonlinear, coupled moment equations. The existence of a positive-definite energy functional guarantees the monotonic convergence of this iteration toward an equilibrium solution (in the absence of magnetic island formation). A renormalization parameter lambda is introduced to ensure the rapid convergence of the Fourier series for x Vector, while simultaneously satisfying the MHD requirement that magnetic field lines are straight in flux coordinates. A descent iteration is also developed for determining the self-consistent value for lambda

Arachnid aloft: directed aerial descent in neotropical canopy spiders.

Science.gov (United States)

Yanoviak, Stephen P; Munk, Yonatan; Dudley, Robert

2015-09-06

The behaviour of directed aerial descent has been described for numerous taxa of wingless hexapods as they fall from the tropical rainforest canopy, but is not known in other terrestrial arthropods. Here, we describe similar controlled aerial behaviours for large arboreal spiders in the genus Selenops (Selenopidae). We dropped 59 such spiders from either canopy platforms or tree crowns in Panama and Peru; the majority (93%) directed their aerial trajectories towards and then landed upon nearby tree trunks. Following initial dorsoventral righting when necessary, falling spiders oriented themselves and then translated head-first towards targets; directional changes were correlated with bilaterally asymmetric motions of the anterolaterally extended forelegs. Aerial performance (i.e. the glide index) decreased with increasing body mass and wing loading, but not with projected surface area of the spider. Along with the occurrence of directed aerial descent in ants, jumping bristletails, and other wingless hexapods, this discovery of targeted gliding in selenopid spiders further indicates strong selective pressures against uncontrolled falls into the understory for arboreal taxa. © 2015 The Author(s).

Mars Exploration Rover Terminal Descent Mission Modeling and Simulation

Science.gov (United States)

Raiszadeh, Behzad; Queen, Eric M.

2004-01-01

Because of NASA's added reliance on simulation for successful interplanetary missions, the MER mission has developed a detailed EDL trajectory modeling and simulation. This paper summarizes how the MER EDL sequence of events are modeled, verification of the methods used, and the inputs. This simulation is built upon a multibody parachute trajectory simulation tool that has been developed in POST I1 that accurately simulates the trajectory of multiple vehicles in flight with interacting forces. In this model the parachute and the suspended bodies are treated as 6 Degree-of-Freedom (6 DOF) bodies. The terminal descent phase of the mission consists of several Entry, Descent, Landing (EDL) events, such as parachute deployment, heatshield separation, deployment of the lander from the backshell, deployment of the airbags, RAD firings, TIRS firings, etc. For an accurate, reliable simulation these events need to be modeled seamlessly and robustly so that the simulations will remain numerically stable during Monte-Carlo simulations. This paper also summarizes how the events have been modeled, the numerical issues, and modeling challenges.

Neuromuscular function during stair descent in meniscectomized patients and controls

DEFF Research Database (Denmark)

Thorlund, Jonas Bloch; Roos, Ewa M; Aagaard, Per

2011-01-01

The aim of this study was to identify differences in knee range of motion (ROM), movement speed, ground reaction forces (GRF) profile, neuromuscular activity, and muscle coactivation during the transition between stair descent and level walking in meniscectomized patients at high risk of knee...

Experimental studies of the rotor flow downwash on the Stability of multi-rotor crafts in descent

Science.gov (United States)

Veismann, Marcel; Dougherty, Christopher; Gharib, Morteza

2017-11-01

All rotorcrafts, including helicopters and multicopters, have the inherent problem of entering rotor downwash during vertical descent. As a result, the craft is subject to highly unsteady flow, called vortex ring state (VRS), which leads to a loss of lift and reduced stability. To date, experimental efforts to investigate this phenomenon have been largely limited to analysis of a single, fixed rotor mounted in a horizontal wind tunnel. Our current work aims to understand the interaction of multiple rotors in vertical descent by mounting a multi-rotor craft in a low speed, vertical wind tunnel. Experiments were performed with a fixed and rotationally free mounting; the latter allowing us to better capture the dynamics of a free flying drone. The effect of rotor separation on stability, generated thrust, and rotor wake interaction was characterized using force gauge data and PIV analysis for various descent velocities. The results obtained help us better understand fluid-craft interactions of drones in vertical descent and identify possible sources of instability. The presented material is based upon work supported by the Center for Autonomous Systems and Technologies (CAST) at the Graduate Aerospace Laboratories of the California Institute of Technology (GALCIT).

Stereotypes of women of Asian descent in midwifery: some evidence.

Science.gov (United States)

Bowler, I M

1993-03-01

The subject of this paper is part of a larger study which investigated the delivery of maternity care to women of South Asian descent in Britain (Bowler, 1990). An ethnographic approach was used and the main method of data collection was non-participant observation in antenatal clinics, labour and postnatal wards in a teaching hospital maternity unit. These observations were supported by data from interviews with midwives. It was found that the midwives commonly use stereotypes of women in order to help them to provide care. These stereotypes are particularly likely to be used in situations where the midwife has difficulty (through pressure of time or other circumstances) in getting to know an individual woman. The stereotype of women of Asian descent contained four main themes: communication problems; failure to comply with care and service abuse; making a fuss about nothing; a lack of normal maternal instinct. Reasons for stereotyping are explored. Effects on service provision in the areas of family planning and breast feeding are highlighted.

Minimum-fuel turning climbout and descent guidance of transport jets

Science.gov (United States)

Neuman, F.; Kreindler, E.

1983-01-01

The complete flightpath optimization problem for minimum fuel consumption from takeoff to landing including the initial and final turns from and to the runway heading is solved. However, only the initial and final segments which contain the turns are treated, since the straight-line climbout, cruise, and descent problems have already been solved. The paths are derived by generating fields of extremals, using the necessary conditions of optimal control together with singular arcs and state constraints. Results show that the speed profiles for straight flight and turning flight are essentially identical except for the final horizontal accelerating or decelerating turns. The optimal turns require no abrupt maneuvers, and an approximation of the optimal turns could be easily integrated with present straight-line climb-cruise-descent fuel-optimization algorithms. Climbout at the optimal IAS rather than the 250-knot terminal-area speed limit would save 36 lb of fuel for the 727-100 aircraft.

Entry, Descent, and Landing Performance for a Mid-Lift-to-Drag Ratio Vehicle at Mars

Science.gov (United States)

Johnson, Breanna J.; Braden, Ellen M.; Sostaric, Ronald R.; Cerimele, Christopher J.; Lu, Ping

2018-01-01

In an effort to mature the design of the Mid-Lift-to-Drag ratio Rigid Vehicle (MRV) candidate of the NASA Evolvable Mars Campaign (EMC) architecture study, end-to-end six-degree-of-freedom (6DOF) simulations are needed to ensure a successful entry, descent, and landing (EDL) design. The EMC study is assessing different vehicle and mission architectures to determine which candidate would be best to deliver a 20 metric ton payload to the surface of Mars. Due to the large mass payload and the relatively low atmospheric density of Mars, all candidates of the EMC study propose to use Supersonic Retro-Propulsion (SRP) throughout the descent and landing phase, as opposed to parachutes, in order to decelerate to a subsonic touchdown. This paper presents a 6DOF entry-to-landing performance and controllability study with sensitivities to dispersions, particularly in the powered descent and landing phases.

Machado-Joseph disease in pedigrees of Azorean descent is linked to chromosome 14.

Science.gov (United States)

St George-Hyslop, P; Rogaeva, E; Huterer, J; Tsuda, T; Santos, J; Haines, J L; Schlumpf, K; Rogaev, E I; Liang, Y; McLachlan, D R

1994-07-01

A locus for Machado-Joseph disease (MJD) has recently been mapped to a 30-cM region of chromosome 14q in five pedigrees of Japanese descent. MJD is a clinically pleomorphic neurodegenerative disease that was originally described in subjects of Azorean descent. In light of the nonallelic heterogeneity in other inherited spinocerebellar ataxias, we were interested to determine if the MJD phenotype in Japanese and Azorean pedigrees arose from mutations at the same locus. We provide evidence that MJD in five pedigrees of Azorean descent is also linked to chromosome 14q in an 18-cM region between the markers D14S67 and AACT (multipoint lod score +7.00 near D14S81). We also report molecular evidence for homozygosity at the MJD locus in an MJD-affected subject with severe, early-onset symptoms. These observations confirm the initial report of linkage of MJD to chromosome 14; suggest that MJD in Japanese and Azorean subjects may represent allelic or identical mutations at the same locus; and provide one possible explanation (MJD gene dosage) for the observed phenotypic heterogeneity in this disease.

Additive preservers of the ascent, descent and related subsets

Czech Academy of Sciences Publication Activity Database

Mbekhta, M.; Müller, Vladimír; Oudghiri, M.

2014-01-01

Roč. 71, č. 1 (2014), s. 63-83 ISSN 0379-4024 R&D Projects: GA ČR GA201/09/0473; GA AV ČR IAA100190903 Institutional support: RVO:67985840 Keywords : additive preservers * ascent * descent Subject RIV: BA - General Mathematics Impact factor: 0.550, year: 2014 http://www.mathjournals.org/jot/2014-071-001/2014-071-001-004.html

Assessing the ability to derive rates of polar middle-atmospheric descent using trace gas measurements from remote sensors

Science.gov (United States)

Ryan, Niall J.; Kinnison, Douglas E.; Garcia, Rolando R.; Hoffmann, Christoph G.; Palm, Mathias; Raffalski, Uwe; Notholt, Justus

2018-02-01

We investigate the reliability of using trace gas measurements from remote sensing instruments to infer polar atmospheric descent rates during winter within 46-86 km altitude. Using output from the Specified Dynamics Whole Atmosphere Community Climate Model (SD-WACCM) between 2008 and 2014, tendencies of carbon monoxide (CO) volume mixing ratios (VMRs) are used to assess a common assumption of dominant vertical advection of tracers during polar winter. The results show that dynamical processes other than vertical advection are not negligible, meaning that the transport rates derived from trace gas measurements do not represent the mean descent of the atmosphere. The relative importance of vertical advection is lessened, and exceeded by other processes, during periods directly before and after a sudden stratospheric warming, mainly due to an increase in eddy transport. It was also found that CO chemistry cannot be ignored in the mesosphere due to the night-time layer of OH at approximately 80 km altitude. CO VMR profiles from the Kiruna Microwave Radiometer and the Microwave Limb Sounder were compared to SD-WACCM output, and show good agreement on daily and seasonal timescales. SD-WACCM CO profiles are combined with the CO tendencies to estimate errors involved in calculating the mean descent of the atmosphere from remote sensing measurements. The results indicate errors on the same scale as the calculated descent rates, and that the method is prone to a misinterpretation of the direction of air motion. The true rate of atmospheric descent is seen to be masked by processes, other than vertical advection, that affect CO. We suggest an alternative definition of the rate calculated using remote sensing measurements: not as the mean descent of the atmosphere, but as an effective rate of vertical transport for the trace gas under observation.

Planetary entry, descent, and landing technologies

Science.gov (United States)

Pichkhadze, K.; Vorontsov, V.; Polyakov, A.; Ivankov, A.; Taalas, P.; Pellinen, R.; Harri, A.-M.; Linkin, V.

2003-04-01

Martian meteorological lander (MML) is intended for landing on the Martian surface in order to monitor the atmosphere at landing point for one Martian year. MMLs shall become the basic elements of a global network of meteorological mini-landers, observing the dynamics of changes of the atmospheric parameters on the Red Planet. The MML main scientific tasks are as follows: (1) Study of vertical structure of the Martian atmosphere throughout the MML descent; (2) On-surface meteorological observations for one Martian year. One of the essential factors influencing the lander's design is its entry, descent, and landing (EDL) sequence. During Phase A of the MML development, five different options for the lander's design were carefully analyzed. All of these options ensure the accomplishment of the above-mentioned scientific tasks with high effectiveness. CONCEPT A (conventional approach): Two lander options (with a parachute system + airbag and an inflatable airbrake + airbag) were analyzed. They are similar in terms of fulfilling braking phases and completely analogous in landing by means of airbags. CONCEPT B (innovative approach): Three lander options were analyzed. The distinguishing feature is the presence of inflatable braking units (IBU) in their configurations. SELECTED OPTION (innovative approach): Incorporating a unique design approach and modern technologies, the selected option of the lander represents a combination of the options analyzed in the framework of Concept B study. Currently, the selected lander option undergoes systems testing (Phase D1). Several MMLs can be delivered to Mars in frameworks of various missions as primary or piggybacking payload: (1) USA-led "Mars Scout" (2007); (2) France-led "NetLander" (2007/2009); (3) Russia-led "Mars-Deimos-Phobos sample return" (2007); (4) Independent mission (currently under preliminary study); etc.

On the efficiency of a randomized mirror descent algorithm in online optimization problems

Science.gov (United States)

Gasnikov, A. V.; Nesterov, Yu. E.; Spokoiny, V. G.

2015-04-01

A randomized online version of the mirror descent method is proposed. It differs from the existing versions by the randomization method. Randomization is performed at the stage of the projection of a subgradient of the function being optimized onto the unit simplex rather than at the stage of the computation of a subgradient, which is common practice. As a result, a componentwise subgradient descent with a randomly chosen component is obtained, which admits an online interpretation. This observation, for example, has made it possible to uniformly interpret results on weighting expert decisions and propose the most efficient method for searching for an equilibrium in a zero-sum two-person matrix game with sparse matrix.

Implementing the Mars Science Laboratory Terminal Descent Sensor Field Test Campaign

Science.gov (United States)

Montgomery, James F.; Bodie, James H.; Brown, Joseph D.; Chen, Allen; Chen, Curtis W.; Essmiller, John C.; Fisher, Charles D.; Goldberg, Hannah R.; Lee, Steven W.; Shaffer, Scott J.

2012-01-01

The Mars Science Laboratory (MSL) will deliver a 900 kg rover to the surface of Mars in August 2012. MSL will utilize a new pulse-Doppler landing radar, the Terminal Descent Sensor (TDS). The TDS employs six narrow-beam antennas to provide unprecedented slant range and velocity performance at Mars to enable soft touchdown of the MSL rover using a unique sky crane Entry, De-scent, and Landing (EDL) technique. Prior to use on MSL, the TDS was put through a rigorous verification and validation (V&V) process. A key element of this V&V was operating the TDS over a series of field tests, using flight-like profiles expected during the descent and landing of MSL over Mars-like terrain on Earth. Limits of TDS performance were characterized with additional testing meant to stress operational modes outside of the expected EDL flight profiles. The flight envelope over which the TDS must operate on Mars encompasses such a large range of altitudes and velocities that a variety of venues were neces-sary to cover the test space. These venues included an F/A-18 high performance aircraft, a Eurocopter AS350 AStar helicopter and 100-meter tall Echo Towers at the China Lake Naval Air Warfare Center. Testing was carried out over a five year period from July 2006 to June 2011. TDS performance was shown, in gen-eral, to be excellent over all venues. This paper describes the planning, design, and implementation of the field test campaign plus results and lessons learned.

Development and test results of a flight management algorithm for fuel conservative descents in a time-based metered traffic environment

Science.gov (United States)

Knox, C. E.; Cannon, D. G.

1980-01-01

A simple flight management descent algorithm designed to improve the accuracy of delivering an airplane in a fuel-conservative manner to a metering fix at a time designated by air traffic control was developed and flight tested. This algorithm provides a three dimensional path with terminal area time constraints (four dimensional) for an airplane to make an idle thrust, clean configured (landing gear up, flaps zero, and speed brakes retracted) descent to arrive at the metering fix at a predetermined time, altitude, and airspeed. The descent path was calculated for a constant Mach/airspeed schedule from linear approximations of airplane performance with considerations given for gross weight, wind, and nonstandard pressure and temperature effects. The flight management descent algorithm is described. The results of the flight tests flown with the Terminal Configured Vehicle airplane are presented.

A Cockpit Comfort Level of the Descent Capsule-Shaped Vehicles

Directory of Open Access Journals (Sweden)

V. E. Minenko

2017-01-01

Full Text Available The article formulates the task of selecting a design-layout pattern for a transport spacecraft, in terms of reaching a proper comfort level for the crew to have appropriate functioning. Using the example of a domestic spacecraft and an American one, it has been shown that the type of launch vehicle, the launch specifics, the operational overloads, and the overall mass restrictions have a dramatic impact on the choice of the design-layout pattern of the spacecraft. The free volume of the pressure cockpit per each member of the crew is considered as the main characteristic to show a level of the spacecraft comfort. Using the average statistical data on the layout density of different equipment, the article estimates the possible increase of this characteristic for the cutting-edge descent vehicles. Using the example of the descent vehicles of Soyuz and Apollo class, the article shows a dependence of the raising weight of a descent vehicle on the free volume of its pressure cockpit. Attention is drawn to the fact that the limit of increasing free space of the spacecraft compartments to achieve maximum comfort should correspond to a set of functions that the crew performs in the compartments considered. Otherwise, the increase in the spacecraft mass will prove to be unjustified. The results stated in the article can be useful to developers of manned spacecraft, as well as to teachers and students. In the long term it is worthwhile adding the article material with the mass and volume indicators, as well as with the estimate results of the comfort level of modern manned spacecrafts being under design in Russia and USA, such as PTK NP (“Federation”, “Orion”, “Dragon V2”.

Block-Based Gradient Descent for Local Backlight Dimming and Flicker Reduction

DEFF Research Database (Denmark)

Burini, Nino; Mantel, Claire; Nadernejad, Ehsan

2014-01-01

Local backlight dimming technology is a two-fold improvement for LED backlit LCD screens that allows to reduce power consumption and increase visual quality. This paper presents a fast version of an iterative backlight dimming algorithm based on gradient descent search. The speed is increased...

The q-G method : A q-version of the Steepest Descent method for global optimization.

Science.gov (United States)

Soterroni, Aline C; Galski, Roberto L; Scarabello, Marluce C; Ramos, Fernando M

2015-01-01

In this work, the q-Gradient (q-G) method, a q-version of the Steepest Descent method, is presented. The main idea behind the q-G method is the use of the negative of the q-gradient vector of the objective function as the search direction. The q-gradient vector, or simply the q-gradient, is a generalization of the classical gradient vector based on the concept of Jackson's derivative from the q-calculus. Its use provides the algorithm an effective mechanism for escaping from local minima. The q-G method reduces to the Steepest Descent method when the parameter q tends to 1. The algorithm has three free parameters and it is implemented so that the search process gradually shifts from global exploration in the beginning to local exploitation in the end. We evaluated the q-G method on 34 test functions, and compared its performance with 34 optimization algorithms, including derivative-free algorithms and the Steepest Descent method. Our results show that the q-G method is competitive and has a great potential for solving multimodal optimization problems.

Are pregnant women of non-Northern European descent more anaemic than women of Northern European descent? A study into the prevalence of anaemia in pregnant women in Amsterdam.

NARCIS (Netherlands)

Jans, S.M.; Daemers, D.O.A.; Vos, R.; Lagro-Janssen, A.L.M.

2009-01-01

OBJECTIVES: to investigate the prevalence of anaemia in pregnancy according to the cut-off points used in the national clinical guideline 'Anaemia in Primary Care Midwifery Practice', and to investigate a possible difference in prevalence between pregnant women of Northern European descent compared

Stochastic Spectral and Conjugate Descent Methods

KAUST Repository

Kovalev, Dmitry

2018-02-11

The state-of-the-art methods for solving optimization problems in big dimensions are variants of randomized coordinate descent (RCD). In this paper we introduce a fundamentally new type of acceleration strategy for RCD based on the augmentation of the set of coordinate directions by a few spectral or conjugate directions. As we increase the number of extra directions to be sampled from, the rate of the method improves, and interpolates between the linear rate of RCD and a linear rate independent of the condition number. We develop and analyze also inexact variants of these methods where the spectral and conjugate directions are allowed to be approximate only. We motivate the above development by proving several negative results which highlight the limitations of RCD with importance sampling.

Stochastic Spectral and Conjugate Descent Methods

KAUST Repository

Kovalev, Dmitry; Gorbunov, Eduard; Gasanov, Elnur; Richtarik, Peter

2018-01-01

The state-of-the-art methods for solving optimization problems in big dimensions are variants of randomized coordinate descent (RCD). In this paper we introduce a fundamentally new type of acceleration strategy for RCD based on the augmentation of the set of coordinate directions by a few spectral or conjugate directions. As we increase the number of extra directions to be sampled from, the rate of the method improves, and interpolates between the linear rate of RCD and a linear rate independent of the condition number. We develop and analyze also inexact variants of these methods where the spectral and conjugate directions are allowed to be approximate only. We motivate the above development by proving several negative results which highlight the limitations of RCD with importance sampling.

Are pregnant women of non-Northern European descent more anaemic than women of Northern European descent? A study into the prevalence of anaemia in pregnant women in Amsterdam

NARCIS (Netherlands)

Jans, S. M. P. J.; Daemers, D. O. A.; de Vos, R.; Lagro-Jansen, A. L. M.

2009-01-01

to investigate the prevalence of anaemia in pregnancy according to the cut-off points used in the national clinical guideline 'Anaemia in Primary Care Midwifery Practice', and to investigate a possible difference in prevalence between pregnant women of Northern European descent compared with women

Are pregnant women of non-Northern European descent more anaemic than women of Northern European descent? A study into the prevalence of anaemia in pregnant women in Amsterdam

NARCIS (Netherlands)

Jans, S.M.P.J.; Daemers, D.O.A.; Vos, R. de; Lagro-Janssen, A.L.M.

2009-01-01

Objectives - to investigate the prevalence of anaemia in pregnancy according to the cut-off points used in the national clinical guideline ‘Anaemia in Primary Care Midwifery Practice’, and to investigate a possible difference in prevalence between pregnant women of Northern European descent compared

Anticipatory kinematics and muscle activity preceding transitions from level-ground walking to stair ascent and descent.

Science.gov (United States)

Peng, Joshua; Fey, Nicholas P; Kuiken, Todd A; Hargrove, Levi J

2016-02-29

The majority of fall-related accidents are during stair ambulation-occurring commonly at the top and bottom stairs of each flight, locations in which individuals are transitioning to stairs. Little is known about how individuals adjust their biomechanics in anticipation of walking-stair transitions. We identified the anticipatory stride mechanics of nine able-bodied individuals as they approached transitions from level ground walking to stair ascent and descent. Unlike prior investigations of stair ambulation, we analyzed two consecutive "anticipation" strides preceding the transitions strides to stairs, and tested a comprehensive set of kinematic and electromyographic (EMG) data from both the leading and trailing legs. Subjects completed ten trials of baseline overground walking and ten trials of walking to stair ascent and descent. Deviations relative to baseline were assessed. Significant changes in mechanics and EMG occurred in the earliest anticipation strides analyzed for both ascent and descent transitions. For stair descent, these changes were consistent with observed reductions in walking speed, which occurred in all anticipation strides tested. For stair ascent, subjects maintained their speed until the swing phase of the latest anticipation stride, and changes were found that would normally be observed for decreasing speed. Given the timing and nature of the observed changes, this study has implications for enhancing intent recognition systems and evaluating fall-prone or disabled individuals, by testing their abilities to sense upcoming transitions and decelerate during locomotion. Copyright © 2016 Elsevier Ltd. All rights reserved.

Nurses of African descent and career advancement.

Science.gov (United States)

Wesley, Yvonne; Dobal, May T

2009-01-01

The purpose of this article is to evaluate a leadership institute designed to promote career advancement and leadership in administration, education, and research among nurses of African descent. Government reports indicate that Black Americans receive lower quality health care than other racial groups even when insurance and income are equal. Moreover, the literature suggests that less than 10% of practicing professional nurses in America are Black-and of these, less than 1% are in senior executive leadership positions. However, the literature lacks detailed discussion of the effectiveness of leadership programs. This article provides an in-depth look at a leadership institute for Black nurses and outlines the impact of the program.

Atmospheric Mars Entry and Landing Investigations & Analysis (AMELIA) by ExoMars 2016 Schiaparelli Entry Descent Module

Science.gov (United States)

Ferri, F.; Karatekin, O.; Aboudan, A.; VanHove, B.; Colombatti, C.; Bettanini, C.; Debei, S.; Lewis, S.; Forget, F.

2017-09-01

On the 19th October 2016, Schiaparelli, the Entry Demonstrator Module (EDM) of the ESA ExoMars Program entered into the martian atmosphere. Although it did not complete a safe landing on Mars, it transmitted data throughout its descent to the surface, until the loss of signal at 1 minute before the expected touch-down on Mars' surface. From the flight data, we reconstruct the actual dynamics of the vehicle during its descent towards Mars's surface and retrieve the atmospheric profile, in terms of density, pressure and temperature, along its trajectory for atmospheric investigations.

Trajectory Guidance for Mars Robotic Precursors: Aerocapture, Entry, Descent, and Landing

Science.gov (United States)

Sostaric, Ronald R.; Zumwalt, Carlie; Garcia-Llama, Eduardo; Powell, Richard; Shidner, Jeremy

2011-01-01

Future crewed missions to Mars require improvements in landed mass capability beyond that which is possible using state-of-the-art Mars Entry, Descent, and Landing (EDL) systems. Current systems are capable of an estimated maximum landed mass of 1-1.5 metric tons (MT), while human Mars studies require 20-40 MT. A set of technologies were investigated by the EDL Systems Analysis (SA) project to assess the performance of candidate EDL architectures. A single architecture was selected for the design of a robotic precursor mission, entitled Exploration Feed Forward (EFF), whose objective is to demonstrate these technologies. In particular, inflatable aerodynamic decelerators (IADs) and supersonic retro-propulsion (SRP) have been shown to have the greatest mass benefit and extensibility to future exploration missions. In order to evaluate these technologies and develop the mission, candidate guidance algorithms have been coded into the simulation for the purposes of studying system performance. These guidance algorithms include aerocapture, entry, and powered descent. The performance of the algorithms for each of these phases in the presence of dispersions has been assessed using a Monte Carlo technique.

'The full has never been told': building a theory of sexual health for heterosexual Black men of Caribbean descent.

Science.gov (United States)

Crowell, Candice N; Delgado-Romero, Edward A; Mosley, Della V; Huynh, Sophia

2016-08-01

Research on Black sexual health often fails to represent the heterogeneity of Black ethnic groups. For people of Caribbean descent in the USA, ethnicity is a salient cultural factor that influences definitions and experiences of sexual health. Most research on people of Caribbean descent focuses on the relatively high rate of STIs, but sexual health is defined more broadly than STI prevalence. Psychological and emotional indicators and the voice of participants are important to consider when exploring the sexual health of a minority culture. The purpose of this study was to qualitatively explore how heterosexual Black men of Caribbean descent define and understand sexual health for themselves. Eleven men who self-identified as Black, Caribbean and heterosexual participated in three focus groups and were asked to define sexual health, critique behaviours expertly identified as healthy and address what encourages and discourages sexual health in their lives. Findings point to six dimensions of sexual health for heterosexual Black men of Caribbean descent. These include: heterosexually privileged, protective, contextual, interpersonal, cultural and pleasurable dimensions. There were some notable departures from current expert definitions of sexual health. Recommendations for further theory development are provided.

Cardiovascular disease, diabetes and established risk factors among populations of sub-Saharan African descent in Europe: a literature review

Directory of Open Access Journals (Sweden)

de Graft Aikins Ama

2009-08-01

Full Text Available Abstract Background Most European countries are ethnically and culturally diverse. Globally, cardiovascular disease (CVD is the leading cause of death. The major risk factors for CVD have been well established. This picture holds true for all regions of the world and in different ethnic groups. However, the prevalence of CVD and related risk factors vary among ethnic groups. Methods This article provides a review of current understanding of the epidemiology of vascular disease, principally coronary heart disease (CHD, stroke and related risk factors among populations of Sub-Sahara African descent (henceforth, African descent in comparison with the European populations in Europe. Results Compared with European populations, populations of African descent have an increased risk of stroke, whereas CHD is less common. They also have higher rates of hypertension and diabetes than European populations. Obesity is highly prevalent, but smoking rate is lower among African descent women. Older people of African descent have more favourable lipid profile and dietary habits than their European counterparts. Alcohol consumption is less common among populations of African descent. The rate of physical activity differs between European countries. Dutch African-Suriname men and women are less physically active than the White-Dutch whereas British African women are more physically active than women in the general population. Literature on psychosocial stress shows inconsistent results. Conclusion Hypertension and diabetes are highly prevalent among African populations, which may explain their high rate of stroke in Europe. The relatively low rate of CHD may be explained by the low rates of other risk factors including a more favourable lipid profile and the low prevalence of smoking. The risk factors are changing, and on the whole, getting worse especially among African women. Cohort studies and clinical trials are therefore needed among these groups to

Distributed Coordinate Descent Method for Learning with Big Data

OpenAIRE

Richtárik, Peter; Takáč, Martin

2013-01-01

In this paper we develop and analyze Hydra: HYbriD cooRdinAte descent method for solving loss minimization problems with big data. We initially partition the coordinates (features) and assign each partition to a different node of a cluster. At every iteration, each node picks a random subset of the coordinates from those it owns, independently from the other computers, and in parallel computes and applies updates to the selected coordinates based on a simple closed-form formula. We give bound...

Convergence results for a class of abstract continuous descent methods

Directory of Open Access Journals (Sweden)

Sergiu Aizicovici

2004-03-01

Full Text Available We study continuous descent methods for the minimization of Lipschitzian functions defined on a general Banach space. We establish convergence theorems for those methods which are generated by approximate solutions to evolution equations governed by regular vector fields. Since the complement of the set of regular vector fields is $sigma$-porous, we conclude that our results apply to most vector fields in the sense of Baire's categories.

Accelerating deep neural network training with inconsistent stochastic gradient descent.

Science.gov (United States)

Wang, Linnan; Yang, Yi; Min, Renqiang; Chakradhar, Srimat

2017-09-01

Stochastic Gradient Descent (SGD) updates Convolutional Neural Network (CNN) with a noisy gradient computed from a random batch, and each batch evenly updates the network once in an epoch. This model applies the same training effort to each batch, but it overlooks the fact that the gradient variance, induced by Sampling Bias and Intrinsic Image Difference, renders different training dynamics on batches. In this paper, we develop a new training strategy for SGD, referred to as Inconsistent Stochastic Gradient Descent (ISGD) to address this problem. The core concept of ISGD is the inconsistent training, which dynamically adjusts the training effort w.r.t the loss. ISGD models the training as a stochastic process that gradually reduces down the mean of batch's loss, and it utilizes a dynamic upper control limit to identify a large loss batch on the fly. ISGD stays on the identified batch to accelerate the training with additional gradient updates, and it also has a constraint to penalize drastic parameter changes. ISGD is straightforward, computationally efficient and without requiring auxiliary memories. A series of empirical evaluations on real world datasets and networks demonstrate the promising performance of inconsistent training. Copyright © 2017 Elsevier Ltd. All rights reserved.

Momentum-weighted conjugate gradient descent algorithm for gradient coil optimization.

Science.gov (United States)

Lu, Hanbing; Jesmanowicz, Andrzej; Li, Shi-Jiang; Hyde, James S

2004-01-01

MRI gradient coil design is a type of nonlinear constrained optimization. A practical problem in transverse gradient coil design using the conjugate gradient descent (CGD) method is that wire elements move at different rates along orthogonal directions (r, phi, z), and tend to cross, breaking the constraints. A momentum-weighted conjugate gradient descent (MW-CGD) method is presented to overcome this problem. This method takes advantage of the efficiency of the CGD method combined with momentum weighting, which is also an intrinsic property of the Levenberg-Marquardt algorithm, to adjust step sizes along the three orthogonal directions. A water-cooled, 12.8 cm inner diameter, three axis torque-balanced gradient coil for rat imaging was developed based on this method, with an efficiency of 2.13, 2.08, and 4.12 mT.m(-1).A(-1) along X, Y, and Z, respectively. Experimental data demonstrate that this method can improve efficiency by 40% and field uniformity by 27%. This method has also been applied to the design of a gradient coil for the human brain, employing remote current return paths. The benefits of this design include improved gradient field uniformity and efficiency, with a shorter length than gradient coil designs using coaxial return paths. Copyright 2003 Wiley-Liss, Inc.

Predictive Modeling for NASA Entry, Descent and Landing Missions

Science.gov (United States)

Wright, Michael

2016-01-01

Entry, Descent and Landing (EDL) Modeling and Simulation (MS) is an enabling capability for complex NASA entry missions such as MSL and Orion. MS is used in every mission phase to define mission concepts, select appropriate architectures, design EDL systems, quantify margin and risk, ensure correct system operation, and analyze data returned from the entry. In an environment where it is impossible to fully test EDL concepts on the ground prior to use, accurate MS capability is required to extrapolate ground test results to expected flight performance.

Long-Time Asymptotics for the Korteweg-de Vries Equation via Nonlinear Steepest Descent

International Nuclear Information System (INIS)

Grunert, Katrin; Teschl, Gerald

2009-01-01

We apply the method of nonlinear steepest descent to compute the long-time asymptotics of the Korteweg-de Vries equation for decaying initial data in the soliton and similarity region. This paper can be viewed as an expository introduction to this method

Attitudes towards and perceptions about contraceptive use among married refugee women of Somali descent living in Finland.

Science.gov (United States)

Degni, F; Koivusilta, L; Ojanlatva, A

2006-09-01

To assess attitudes towards and perceptions about contraceptive use among married refugee women of Somali descent living in Finland. A sample of 100 married refugee women of Somali descent (18-50 years of age) were invited to participate in a study on contraceptive use in Finland (30 women refused). Qualitative and quantitative methods were used to collect the data. Questionnaire of the first data set was written in the Somali language. Interviews were conducted in the Somali language. The attitudes and opinions of these women towards contraceptive use (73% did not use contraceptives, 27% did use them) were connected with religious beliefs and issues involving marital relations. Religious or gender issues did not seem to influence those who used contraception. The findings indicated that the majority of the married refugee women of Somali descent living in Finland did not use contraception. The process of starting the use of contraception was possible because of an access to good reproductive health care and family planning services, changes in life situations, and adaptations to Finnish social and cultural norms.

Dictionary Learning Based on Nonnegative Matrix Factorization Using Parallel Coordinate Descent

Directory of Open Access Journals (Sweden)

Zunyi Tang

2013-01-01

Full Text Available Sparse representation of signals via an overcomplete dictionary has recently received much attention as it has produced promising results in various applications. Since the nonnegativities of the signals and the dictionary are required in some applications, for example, multispectral data analysis, the conventional dictionary learning methods imposed simply with nonnegativity may become inapplicable. In this paper, we propose a novel method for learning a nonnegative, overcomplete dictionary for such a case. This is accomplished by posing the sparse representation of nonnegative signals as a problem of nonnegative matrix factorization (NMF with a sparsity constraint. By employing the coordinate descent strategy for optimization and extending it to multivariable case for processing in parallel, we develop a so-called parallel coordinate descent dictionary learning (PCDDL algorithm, which is structured by iteratively solving the two optimal problems, the learning process of the dictionary and the estimating process of the coefficients for constructing the signals. Numerical experiments demonstrate that the proposed algorithm performs better than the conventional nonnegative K-SVD (NN-KSVD algorithm and several other algorithms for comparison. What is more, its computational consumption is remarkably lower than that of the compared algorithms.

Kinematic analyses during stair descent in young women with patellofemoral pain.

Science.gov (United States)

Grenholm, Anton; Stensdotter, Ann-Katrin; Häger-Ross, Charlotte

2009-01-01

Compensatory movement strategies may develop in response to pain to avoid stress on the affected area. Patellofemoral pain is characterised by intermittent periods of pain and the present study addresses whether long-term pain leads to compensatory movement strategies that remain even when the pain is absent. Lower extremity kinematics in three dimensions was studied in stair descent in 17 women with patellofemoral and in 17 matched controls. A two-dimensional geometric model was constructed to normalise kinematic data for subjects with varying anthropometrics when negotiating stairs of fixed proportions. There were minor differences in movement patterns between groups. Knee joint angular velocity in the stance leg at foot contact was lower and the movement trajectory tended to be jerkier in the patellofemoral group. The two-dimensional model showed greater plantar flexion in the swing leg in preparation for foot placement in the patellofemoral group. The results indicate that an altered stair descent strategy in the patellofemoral group may remain also in the absence of pain. The biomechanical interpretation presumes that the strategy is aimed to reduce knee joint loading by less knee joint moment and lower impact force.

Vertical Descent and Landing Tests of a 0.13-Scale Model of the Convair XFY-1 Vertically Rising Airplane in Still Air, TED No. NACA DE 368

Science.gov (United States)

Smith, Charlee C., Jr.; Lovell, Powell M., Jr.

1954-01-01

An investigation is being conducted to determine the dynamic stability and control characteristics of a 0.13-scale flying model of Convair XFY-1 vertically rising airplane. This paper presents the results of flight and force tests to determine the stability and control characteristics of the model in vertical descent and landings in still air. The tests indicated that landings, including vertical descent from altitudes representing up to 400 feet for the full-scale airplane and at rates of descent up to 15 or 20 feet per second (full scale), can be performed satisfactorily. Sustained vertical descent in still air probably will be more difficult to perform because of large random trim changes that become greater as the descent velocity is increased. A slight steady head wind or cross wind might be sufficient to eliminate the random trim changes.

Vehicle Staging Analysis of the Transition to Supersonic Retropropulsion During Mars Entry, Descent, and Landing

Data.gov (United States)

National Aeronautics and Space Administration — The landing of the Mars Science Laboratory represents the upper limit of current Entry, Descent, and Landing (EDL) capabilities for Mars exploration. The succession...

Seasonal variability and descent of mid-latitude sporadic E layers at Arecibo

Directory of Open Access Journals (Sweden)

N. Christakis

2009-03-01

Full Text Available Sporadic E layers (Es follow regular daily patterns in variability and altitude descent, which are determined primarily by the vertical tidal wind shears in the lower thermosphere. In the present study a large set of sporadic E layer incoherent scatter radar (ISR measurements are analyzed. These were made at Arecibo (Geog. Lat. ~18° N; Magnetic Dip ~50° over many years with ISR runs lasting from several hours to several days, covering evenly all seasons. A new methodology is applied, in which both weak and strong layers are clearly traced by using the vertical electron density gradient as a function of altitude and time. Taking a time base equal to the 24-h local day, statistics were obtained on the seasonal behavior of the diurnal and semidiurnal tidal variability and altitude descent patterns of sporadic E at Arecibo. The diurnal tide, most likely the S(1,1 tide with a vertical wavelength around 25 km, controls fully the formation and descent of the metallic Es layers at low altitudes below 110 km. At higher altitudes, there are two prevailing layers formed presumably by vertical wind shears associated mainly with semidiurnal tides. These include: 1 a daytime layer starting at ~130 km around midday and descending down to 105 km by local midnight, and 2 a less frequent and weaker nighttime layer which starts prior to midnight at ~130 km, descending downwards at somewhat faster rate to reach 110 km by sunrise. The diurnal and semidiurnal-like pattern prevails, with some differences, in all seasons. The differences in occurrence, strength and descending speeds between the daytime and nighttime upper layers are not well understood from the present data alone and require further study.

Scaling Up Coordinate Descent Algorithms for Large ℓ1 Regularization Problems

Energy Technology Data Exchange (ETDEWEB)

Scherrer, Chad; Halappanavar, Mahantesh; Tewari, Ambuj; Haglin, David J.

2012-07-03

We present a generic framework for parallel coordinate descent (CD) algorithms that has as special cases the original sequential algorithms of Cyclic CD and Stochastic CD, as well as the recent parallel Shotgun algorithm of Bradley et al. We introduce two novel parallel algorithms that are also special cases---Thread-Greedy CD and Coloring-Based CD---and give performance measurements for an OpenMP implementation of these.

Gradient descent learning in and out of equilibrium

International Nuclear Information System (INIS)

Caticha, Nestor; Araujo de Oliveira, Evaldo

2001-01-01

Relations between the off thermal equilibrium dynamical process of on-line learning and the thermally equilibrated off-line learning are studied for potential gradient descent learning. The approach of Opper to study on-line Bayesian algorithms is used for potential based or maximum likelihood learning. We look at the on-line learning algorithm that best approximates the off-line algorithm in the sense of least Kullback-Leibler information loss. The closest on-line algorithm works by updating the weights along the gradient of an effective potential, which is different from the parent off-line potential. A few examples are analyzed and the origin of the potential annealing is discussed

A unified framework of descent algorithms for nonlinear programs and variational inequalities

International Nuclear Information System (INIS)

Patriksson, M.

1993-01-01

We present a framework of algorithms for the solution of continuous optimization and variational inequality problems. In the general algorithm, a search direction finding auxiliary problems is obtained by replacing the original cost function with an approximating monotone cost function. The proposed framework encompasses algorithm classes presented earlier by Cohen, Dafermos, Migdalas, and Tseng, and includes numerous descent and successive approximation type methods, such as Newton methods, Jacobi and Gauss-Siedel type decomposition methods for problems defined over Cartesian product sets, and proximal point methods, among others. The auxiliary problem of the general algorithm also induces equivalent optimization reformulation and descent methods for asymmetric variational inequalities. We study the convergence properties of the general algorithm when applied to unconstrained optimization, nondifferentiable optimization, constrained differentiable optimization, and variational inequalities; the emphasis of the convergence analyses is placed on basic convergence results, convergence using different line search strategies and truncated subproblem solutions, and convergence rate results. This analysis offer a unification of known results; moreover, it provides strengthenings of convergence results for many existing algorithms, and indicates possible improvements of their realizations. 482 refs

Entry, Descent, and Landing Communications for the 2011 Mars Science Laboratory

Science.gov (United States)

Abilleira, Fernando; Shidner, Jeremy D.

2012-01-01

The Mars Science Laboratory (MSL), established as the most advanced rover to land on the surface of Mars to date, launched on November 26th, 2011 and arrived to the Martian Gale Crater during the night of August 5th, 2012 (PDT). MSL will investigate whether the landing region was ever suitable to support carbon-based life, and examine rocks, soil, and the atmosphere with a sophisticated suite of tools. This paper addresses the flight system requirement by which the vehicle transmitted indications of the following events using both X-band tones and UHF telemetry to allow identification of probable root causes should a mission anomaly have occurred: Heat-Rejection System (HRS) venting, completion of the cruise stage separation, turn to entry attitude, atmospheric deceleration, bank angle reversal commanded, parachute deployment, heatshield separation, radar ground acquisition, powered descent initiation, rover separation from the descent stage, and rover release. During Entry, Descent, and Landing (EDL), the flight system transmitted a UHF telemetry stream adequate to determine the state of the spacecraft (including the presence of faults) at 8 kbps initiating from cruise stage separation through at least one minute after positive indication of rover release on the surface of Mars. The flight system also transmitted X-band semaphore tones from Entry to Landing plus one minute although since MSL was occulted, as predicted, by Mars as seen from the Earth, Direct-To-Earth (DTE) communications were interrupted at approximately is approx. 5 min after Entry ( approximately 130 prior to Landing). The primary data return paths were through the Deep Space Network (DSN) for DTE and the existing Mars network of orbiting assets for UHF, which included the Mars Reconnaissance Orbiter (MRO), Mars Odyssey (ODY), and Mars Express (MEX) elements. These orbiters recorded the telemetry data stream and returned it back to Earth via the DSN. The paper also discusses the total power

Modelling the descent of nitric oxide during the elevated stratopause event of January 2013

Science.gov (United States)

Orsolini, Yvan J.; Limpasuvan, Varavut; Pérot, Kristell; Espy, Patrick; Hibbins, Robert; Lossow, Stefan; Raaholt Larsson, Katarina; Murtagh, Donal

2017-03-01

Using simulations with a whole-atmosphere chemistry-climate model nudged by meteorological analyses, global satellite observations of nitrogen oxide (NO) and water vapour by the Sub-Millimetre Radiometer instrument (SMR), of temperature by the Microwave Limb Sounder (MLS), as well as local radar observations, this study examines the recent major stratospheric sudden warming accompanied by an elevated stratopause event (ESE) that occurred in January 2013. We examine dynamical processes during the ESE, including the role of planetary wave, gravity wave and tidal forcing on the initiation of the descent in the mesosphere-lower thermosphere (MLT) and its continuation throughout the mesosphere and stratosphere, as well as the impact of model eddy diffusion. We analyse the transport of NO and find the model underestimates the large descent of NO compared to SMR observations. We demonstrate that the discrepancy arises abruptly in the MLT region at a time when the resolved wave forcing and the planetary wave activity increase, just before the elevated stratopause reforms. The discrepancy persists despite doubling the model eddy diffusion. While the simulations reproduce an enhancement of the semi-diurnal tide following the onset of the 2013 SSW, corroborating new meteor radar observations at high northern latitudes over Trondheim (63.4°N), the modelled tidal contribution to the forcing of the mean meridional circulation and to the descent is a small portion of the resolved wave forcing, and lags it by about ten days.

Entry, Descent and Landing Systems Analysis: Exploration Feed Forward Internal Peer Review Slide Package

Science.gov (United States)

Dwyer Cianciolo, Alicia M. (Editor)

2011-01-01

NASA senior management commissioned the Entry, Descent and Landing Systems Analysis (EDL-SA) Study in 2008 to identify and roadmap the Entry, Descent and Landing (EDL) technology investments that the agency needed to successfully land large payloads at Mars for both robotic and human-scale missions. Year 1 of the study focused on technologies required for Exploration-class missions to land payloads of 10 to 50 mt. Inflatable decelerators, rigid aeroshell and supersonic retro-propulsion emerged as the top candidate technologies. In Year 2 of the study, low TRL technologies identified in Year 1, inflatables aeroshells and supersonic retropropulsion, were combined to create a demonstration precursor robotic mission. This part of the EDL-SA Year 2 effort, called Exploration Feed Forward (EFF), took much of the systems analysis simulation and component model development from Year 1 to the next level of detail.

Error analysis of stochastic gradient descent ranking.

Science.gov (United States)

Chen, Hong; Tang, Yi; Li, Luoqing; Yuan, Yuan; Li, Xuelong; Tang, Yuanyan

2013-06-01

Ranking is always an important task in machine learning and information retrieval, e.g., collaborative filtering, recommender systems, drug discovery, etc. A kernel-based stochastic gradient descent algorithm with the least squares loss is proposed for ranking in this paper. The implementation of this algorithm is simple, and an expression of the solution is derived via a sampling operator and an integral operator. An explicit convergence rate for leaning a ranking function is given in terms of the suitable choices of the step size and the regularization parameter. The analysis technique used here is capacity independent and is novel in error analysis of ranking learning. Experimental results on real-world data have shown the effectiveness of the proposed algorithm in ranking tasks, which verifies the theoretical analysis in ranking error.

Optimization algorithm based on densification and dynamic canonical descent

Science.gov (United States)

Bousson, K.; Correia, S. D.

2006-07-01

Stochastic methods have gained some popularity in global optimization in that most of them do not assume the cost functions to be differentiable. They have capabilities to avoid being trapped by local optima, and may converge even faster than gradient-based optimization methods on some problems. The present paper proposes an optimization method, which reduces the search space by means of densification curves, coupled with the dynamic canonical descent algorithm. The performances of the new method are shown on several known problems classically used for testing optimization algorithms, and proved to outperform competitive algorithms such as simulated annealing and genetic algorithms.

Sufficient Descent Conjugate Gradient Methods for Solving Convex Constrained Nonlinear Monotone Equations

Directory of Open Access Journals (Sweden)

San-Yang Liu

2014-01-01

Full Text Available Two unified frameworks of some sufficient descent conjugate gradient methods are considered. Combined with the hyperplane projection method of Solodov and Svaiter, they are extended to solve convex constrained nonlinear monotone equations. Their global convergence is proven under some mild conditions. Numerical results illustrate that these methods are efficient and can be applied to solve large-scale nonsmooth equations.

Interaction between ADH1B*3 and alcohol-facilitating social environments in alcohol behaviors among college students of african descent.

Science.gov (United States)

Desalu, Jessica M; Zaso, Michelle J; Kim, Jueun; Belote, John M; Park, Aesoon

2017-06-01

Although alcohol-facilitating social environmental factors, such as alcohol offers and high perceived peer drinking norms, have been extensively studied as determinants of college drinking, their role among college students of African descent remains understudied. Furthermore, gene-environment interaction research suggests that the effects of alcohol-facilitating environments may differ as a function of genetic factors. Specifically, the alcohol dehydrogenase gene's ADH1B*3 allele, found almost exclusively in persons of African descent, may modulate the association of risky social environments with alcohol behaviors. The current study examined whether the ADH1B*3 allele attenuated the relationship between alcohol-facilitating environments (ie, alcohol offers and perceived peer drinking norms) and alcohol behaviors. Participants were 241 undergraduate students who self-identified as being of African descent (mean age = 20 years [SD = 4.11]; 66% female). Significant interaction effects of ADH1B*3 with alcohol offers were found on alcohol use frequency (incidence rate ratio [IRR] = 1.14) and on drinking consequences (IRR = 1.21). ADH1B*3 also interacted with perceived peer norms on drinking consequences (IRR = 1.41). Carriers of the ADH1B*3 allele drank less frequently and experienced fewer negative consequences than non-carriers when exposed to lower levels of alcohol offers and perceived peer drinking. In contrast, in high alcohol-facilitating environments, no protective genetic effect was observed. This study demonstrates that ADH1B*3 may protect college students of African descent against alcohol outcomes, although only in low alcohol-facilitating environments. Findings add to the growing body of knowledge regarding genetic and social determinants of alcohol behaviors among college students of African descent. (Am J Addict 2017;26:349-356). © 2017 American Academy of Addiction Psychiatry.

Dynamic gradient descent learning algorithms for enhanced empirical modeling of power plants

International Nuclear Information System (INIS)

Parlos, A.G.; Atiya, Amir; Chong, K.T.

1991-01-01

A newly developed dynamic gradient descent-based learning algorithm is used to train a recurrent multilayer perceptron network for use in empirical modeling of power plants. The two main advantages of the proposed learning algorithm are its ability to consider past error gradient information for future use and the two forward passes associated with its implementation, instead of one forward and one backward pass of the backpropagation algorithm. The latter advantage results in computational time saving because both passes can be performed simultaneously. The dynamic learning algorithm is used to train a hybrid feedforward/feedback neural network, a recurrent multilayer perceptron, which was previously found to exhibit good interpolation and extrapolation capabilities in modeling nonlinear dynamic systems. One of the drawbacks, however, of the previously reported work has been the long training times associated with accurate empirical models. The enhanced learning capabilities provided by the dynamic gradient descent-based learning algorithm are demonstrated by a case study of a steam power plant. The number of iterations required for accurate empirical modeling has been reduced from tens of thousands to hundreds, thus significantly expediting the learning process

Evaluation of vertical profiles to design continuous descent approach procedure

Science.gov (United States)

Pradeep, Priyank

The current research focuses on predictability, variability and operational feasibility aspect of Continuous Descent Approach (CDA), which is among the key concepts of the Next Generation Air Transportation System (NextGen). The idle-thrust CDA is a fuel economical, noise and emission abatement procedure, but requires increased separation to accommodate for variability and uncertainties in vertical and speed profiles of arriving aircraft. Although a considerable amount of researches have been devoted to the estimation of potential benefits of the CDA, only few have attempted to explain the predictability, variability and operational feasibility aspect of CDA. The analytical equations derived using flight dynamics and Base of Aircraft and Data (BADA) Total Energy Model (TEM) in this research gives insight into dependency of vertical profile of CDA on various factors like wind speed and gradient, weight, aircraft type and configuration, thrust settings, atmospheric factors (deviation from ISA (DISA), pressure and density of the air) and descent speed profile. Application of the derived equations to idle-thrust CDA gives an insight into sensitivity of its vertical profile to multiple factors. This suggests fixed geometric flight path angle (FPA) CDA has higher degree of predictability and lesser variability at the cost of non-idle and low thrust engine settings. However, with optimized design this impact can be overall minimized. The CDA simulations were performed using Future ATM Concept Evaluation Tool (FACET) based on radar-track and aircraft type data (BADA) of the real air-traffic to some of the busiest airports in the USA (ATL, SFO and New York Metroplex (JFK, EWR and LGA)). The statistical analysis of the vertical profiles of CDA shows 1) mean geometric FPAs derived from various simulated vertical profiles are consistently shallower than 3° glideslope angle and 2) high level of variability in vertical profiles of idle-thrust CDA even in absence of

Entry, Descent and Landing Systems Analysis Study: Phase 2 Report on Exploration Feed-Forward Systems

Science.gov (United States)

Dwyer Ciancolo, Alicia M.; Davis, Jody L.; Engelund, Walter C.; Komar, D. R.; Queen, Eric M.; Samareh, Jamshid A.; Way, David W.; Zang, Thomas A.; Murch, Jeff G.; Krizan, Shawn A.;

Parents and Siblings As Early Resources for Young Children's Learning in Mexican-Descent Families.

Science.gov (United States)

Perez-Granados, Deanne R.; Callanan, Maureen A.

1997-01-01

Interviews with parents from 50 Mexican-descent families revealed that parents encouraged their preschool children to ask questions about science and causal relationships; older and younger siblings learned different skills from one another; and children learned through observation and imitation. Discusses issues of "match" between home…

Kinetic comparison of older men and women during walk-to-stair descent transition.

Science.gov (United States)

Singhal, Kunal; Kim, Jemin; Casebolt, Jeffrey; Lee, Sangwoo; Han, Ki Hoon; Kwon, Young-Hoo

2014-09-01

Stair walking is one of the most challenging tasks for older adults, with women reporting higher incidence of falls. The purpose of this study was to investigate the gender differences in kinetics during stair descent transition. Twenty-eight participants (12 male and 16 female; 68.5 and 69.0 years of mean age, respectively) performed stair descent from level walking in a step-over-step manner at a self-selected speed over a custom-made three-step staircase with embedded force plates. Kinematic and force data were combined using inverse dynamics to generate kinetic data for gender comparison. The top and the first step on the staircase were chosen for analysis. Women showed a higher trail leg peak hip abductor moment (-1.0 Nm/kg), lower trail leg peak knee extensor moment and eccentric power (0.74 Nm/kg and 3.15 W/kg), and lower peak concentric power at trail leg ankle joint (1.29 W/kg) as compared to men (ppredispose women to a higher risk of fall. Copyright © 2014 Elsevier B.V. All rights reserved.

Influence of working memory and executive function on stair ascent and descent in young and older adults.

Science.gov (United States)

Gaillardin, Florence; Baudry, Stéphane

2018-06-01

This study assessed the influence of attention division, working memory and executive function on stair ascent and descent in young and older adults. Twenty young (25.5 ± 2.1 yrs) and 20 older adults (68.4 ± 5.4 yrs) ascended and descended a 3-step staircase with no simultaneous cognitive task (single-motor task) or while performing a cognitive task (dual-task condition). The cognitive task involved either 1) recalling a word list of the subject's word-span minus 2 words (SPAN-2) to assess the attention division effect, 2) a word list of subject's word-span (SPAN-O) to assess the working memory effect, or 3) recalling in alphabetical order, a word list of the subject's word-span (SPAN-A) to assess the executive function effect. Word-span corresponds to the longest string of words that can be recalled correctly. The duration of ascent and descent of stairs was used to assess the cognitive-motor interaction. Stair ascent and descent duration did not differ between age groups for the single-motor task, and was similar between single-motor task and SPAN-2 in both groups (p > 0.05). In contrast, stair ascent and descent duration increased with SPAN-O compared with SPAN-2 for both groups (p SPAN-A than SPAN-O only in older adults. Healthy aging was not associated with a decrease in the capacity to perform motor-cognitive dual tasks that involved ascending and descending of stairs when the cognitive task only required working memory. However, the decrease in dual-task performance involving executive functioning may reflect a subclinical cognitive decline in healthy older adults. Copyright © 2018 Elsevier Inc. All rights reserved.

Ti and N adatom descent pathways to the terrace from atop two-dimensional TiN/TiN(001) islands

Energy Technology Data Exchange (ETDEWEB)

Edström, D., E-mail: daned@ifm.liu.se [Department of Physics, Chemistry and Biology (IFM), Linköping University, SE-58183 Linköping (Sweden); Sangiovanni, D.G.; Hultman, L.; Chirita, V. [Department of Physics, Chemistry and Biology (IFM), Linköping University, SE-58183 Linköping (Sweden); Petrov, I.; Greene, J.E. [Department of Physics, Chemistry and Biology (IFM), Linköping University, SE-58183 Linköping (Sweden); Frederick Seitz Materials Research Laboratory and the Materials Science Department, University of Illinois at Urbana-Champaign, Urbana, IL 61801 (United States)

2014-05-02

We use classical molecular dynamics and the modified embedded atom method to determine residence times and descent pathways of Ti and N adatoms on square, single-atom-high, TiN islands on TiN(001). Simulations are carried out at 1000 K, which is within the optimal range for TiN(001) epitaxial growth. Results show that the frequency of descent events, and overall adatom residence times, depend strongly on both the TiN(001) diffusion barrier for each species as well as the adatom island-edge location immediately prior to descent. Ti adatoms, with a low diffusion barrier, rapidly move toward the island periphery, via funneling, where they diffuse along upper island edges. The primary descent mechanism for Ti adatoms is via push-out/exchange with Ti island-edge atoms, a process in which the adatom replaces an island edge atom by moving down while pushing the edge atom out onto the terrace to occupy an epitaxial position along the island edge. Double push-out events are also observed for Ti adatoms descending at N corner positions. N adatoms, with a considerably higher diffusion barrier on TiN(001), require much longer times to reach island edges and, consequently, have significantly longer residence times. N adatoms are found to descend onto the terrace by direct hopping over island edges and corner atoms, as well as by concerted push-out/exchange with N atoms adjacent to Ti corners. For both adspecies, we also observe several complex adatom/island interactions, before and after descent onto the terrace, including two instances of Ti island-atom ascent onto the island surface. - Highlights: • We use classical molecular dynamics to model Ti and N adatom migration on TiN(001) islands. • N adatoms remain on islands significantly longer than Ti adatoms. • Ti adatoms descend via push-out/exchange, N adatoms primarily by direct hops. • N adatoms act as precursors for multilayer formation and surface roughening.

Ti and N adatom descent pathways to the terrace from atop two-dimensional TiN/TiN(001) islands

International Nuclear Information System (INIS)

Edström, D.; Sangiovanni, D.G.; Hultman, L.; Chirita, V.; Petrov, I.; Greene, J.E.

2014-01-01

We use classical molecular dynamics and the modified embedded atom method to determine residence times and descent pathways of Ti and N adatoms on square, single-atom-high, TiN islands on TiN(001). Simulations are carried out at 1000 K, which is within the optimal range for TiN(001) epitaxial growth. Results show that the frequency of descent events, and overall adatom residence times, depend strongly on both the TiN(001) diffusion barrier for each species as well as the adatom island-edge location immediately prior to descent. Ti adatoms, with a low diffusion barrier, rapidly move toward the island periphery, via funneling, where they diffuse along upper island edges. The primary descent mechanism for Ti adatoms is via push-out/exchange with Ti island-edge atoms, a process in which the adatom replaces an island edge atom by moving down while pushing the edge atom out onto the terrace to occupy an epitaxial position along the island edge. Double push-out events are also observed for Ti adatoms descending at N corner positions. N adatoms, with a considerably higher diffusion barrier on TiN(001), require much longer times to reach island edges and, consequently, have significantly longer residence times. N adatoms are found to descend onto the terrace by direct hopping over island edges and corner atoms, as well as by concerted push-out/exchange with N atoms adjacent to Ti corners. For both adspecies, we also observe several complex adatom/island interactions, before and after descent onto the terrace, including two instances of Ti island-atom ascent onto the island surface. - Highlights: • We use classical molecular dynamics to model Ti and N adatom migration on TiN(001) islands. • N adatoms remain on islands significantly longer than Ti adatoms. • Ti adatoms descend via push-out/exchange, N adatoms primarily by direct hops. • N adatoms act as precursors for multilayer formation and surface roughening

Failure Bounding And Sensitivity Analysis Applied To Monte Carlo Entry, Descent, And Landing Simulations

Science.gov (United States)

Gaebler, John A.; Tolson, Robert H.

2010-01-01

In the study of entry, descent, and landing, Monte Carlo sampling methods are often employed to study the uncertainty in the designed trajectory. The large number of uncertain inputs and outputs, coupled with complicated non-linear models, can make interpretation of the results difficult. Three methods that provide statistical insights are applied to an entry, descent, and landing simulation. The advantages and disadvantages of each method are discussed in terms of the insights gained versus the computational cost. The first method investigated was failure domain bounding which aims to reduce the computational cost of assessing the failure probability. Next a variance-based sensitivity analysis was studied for the ability to identify which input variable uncertainty has the greatest impact on the uncertainty of an output. Finally, probabilistic sensitivity analysis is used to calculate certain sensitivities at a reduced computational cost. These methods produce valuable information that identifies critical mission parameters and needs for new technology, but generally at a significant computational cost.

NON–DESCENT VAGINAL HYSTERECTOMY FOR BENIGN GYNAECOLOGICAL DISEASE – A PROSPECTIVE STUDY

Directory of Open Access Journals (Sweden)

Thulasi

2016-04-01

Full Text Available OBJECTIVE To assess safety and feasibility of non-descent vaginal hysterectomy for benign gynaecological disease. METHODS A prospective study was conducted at the Department of Obstetrics and Gynaecology of P K Das Institute of Medical Sciences from January 2013 to December 2013. An effort was made to perform hysterectomies vaginally in women with benign or premalignant conditions in the absence of prolapse. A suspected adnexal pathology, endometriosis, immobility of uterus, uterus size more than 16 weeks was excluded from the study. Vaginal hysterectomy was done in usual manner. In bigger size uterus, morcellation techniques like bisection, debulking, coring, myomectomy, or combination of these were used to remove the uterus. Data regarding age, parity, uterine size, estimated blood loss, length of operation, intraoperative and postoperative complications and hospital stay were recorded. RESULTS A total of 100 cases were selected for non-descent vaginal hysterectomy. Among them, 97 cases successfully underwent nondescent vaginal hysterectomy. Majority of the patients (55% were in age group 40-45 yrs. Four patients were nulligravida and eight patients had previous LSCS. Uterine size was ≤ 12 weeks in 84 cases and > 12-16 weeks in 16 cases. Commonest indication was leiomyoma of uterus (43%. Mean duration of surgery was 70±20.5 minutes. Mean blood loss was 150±65 mL. Reasons for failure to perform NDVH was difficulty in opening pouch of Douglas in two cases because of adhesions and in one case there was difficulty in reaching the fundal myoma which prevented the uterine descent. Intra–operatively, one case had bladder injury (1% that had previous 2 LSCS. Postoperatively, complications were minimal which included postoperative fever (11%, UTI (8% and vaginal cuff infection was (4%. Mean hospital stay was 3.5 days. CONCLUSION Vaginal hysterectomy is safe, feasible in most of the women requiring hysterectomy for benign conditions with less

Fast alternating projected gradient descent algorithms for recovering spectrally sparse signals

KAUST Repository

Cho, Myung

2016-06-24

We propose fast algorithms that speed up or improve the performance of recovering spectrally sparse signals from un-derdetermined measurements. Our algorithms are based on a non-convex approach of using alternating projected gradient descent for structured matrix recovery. We apply this approach to two formulations of structured matrix recovery: Hankel and Toeplitz mosaic structured matrix, and Hankel structured matrix. Our methods provide better recovery performance, and faster signal recovery than existing algorithms, including atomic norm minimization.

Fast alternating projected gradient descent algorithms for recovering spectrally sparse signals

KAUST Repository

Cho, Myung; Cai, Jian-Feng; Liu, Suhui; Eldar, Yonina C.; Xu, Weiyu

2016-01-01

We propose fast algorithms that speed up or improve the performance of recovering spectrally sparse signals from un-derdetermined measurements. Our algorithms are based on a non-convex approach of using alternating projected gradient descent for structured matrix recovery. We apply this approach to two formulations of structured matrix recovery: Hankel and Toeplitz mosaic structured matrix, and Hankel structured matrix. Our methods provide better recovery performance, and faster signal recovery than existing algorithms, including atomic norm minimization.

Terrain reconstruction based on descent images for the Chang’e III landing area

Directory of Open Access Journals (Sweden)

Xu Xinchao

2015-10-01

Full Text Available A new method that combined image matching and shape from shading for terrain reconstruction was proposed to solve the lack of terrain in the landing area of Chang'e III. First, the reflection equation was established based on the Lommel– Seeliger reflection model. After edge extraction, the gradients of points on the edge were solved. The normal vectors of adjacent points were obtained using the smoothness constraint. Furthermore, the gradients of residual points in the image were determined through evolution. The inadequacy of the reflection equation was eliminated by considering the gradient as the constraint of the reflection equation. The normal vector of each point could be obtained by solving the reflection equation. The terrain without coordinate information was reconstructed by iterating the vector field. After using scaleinvariant feature transform to extract matching points in the descent images, the terrain was converted to a lander centroid coordinate system. Experiments were carried out with MATLAB-simulated images, laboratory images, and descent images of Chang'e III. Results show that the proposed method performs better than the classical SFS algorithm. The new method can provide reference for other deep space exploration activities.

Computational Experience with Globally Convergent Descent Methods for Large Sparse Systems of Nonlinear Equations

Czech Academy of Sciences Publication Activity Database

Lukšan, Ladislav; Vlček, Jan

1998-01-01

Roč. 8, č. 3-4 (1998), s. 201-223 ISSN 1055-6788 R&D Projects: GA ČR GA201/96/0918 Keywords : nonlinear equations * Armijo-type descent methods * Newton-like methods * truncated methods * global convergence * nonsymmetric linear systems * conjugate gradient -type methods * residual smoothing * computational experiments Subject RIV: BB - Applied Statistics, Operational Research

Joint loading decreased by inexpensive and minimalist footwear in elderly women with knee osteoarthritis during stair descent.

Science.gov (United States)

Sacco, I C N; Trombini-Souza, F; Butugan, M K; Pássaro, A C; Arnone, A C; Fuller, R

2012-03-01

Previous studies indicate that flexible footwear, which mimics the biomechanics of walking barefoot, results in decreased knee loads in patients with knee osteoarthritis (OA) during walking. However, the effect of flexible footwear on other activities of daily living, such as descending stairs, remains unclear. Our objective was to evaluate the influence of inexpensive and minimalist footwear (Moleca) on knee adduction moment (KAM) during stair descent of elderly women with and without knee OA. Thirty-four elderly women were equally divided into an OA group and a control group (CG). Stair descent was evaluated in barefoot condition, while wearing the Moleca, and while wearing heeled shoes. Kinematics and ground reaction forces were measured to calculate KAM by using inverse dynamics. The OA group experienced a higher KAM during midstance under the barefoot condition (233.3%; P = 0.028), the Moleca (379.2%; P = 0.004), and heeled shoes (217.6%; P = 0.007). The OA group had a similar knee load during early, mid, and late stance with the Moleca compared with the barefoot condition. Heeled shoes increased the knee loads during the early-stance (versus barefoot [16.7%; P stair descent. The loads are similar to the barefoot condition and effectively decreased when compared with heeled shoes. Copyright © 2012 by the American College of Rheumatology.

Stochastic Spectral Descent for Discrete Graphical Models

International Nuclear Information System (INIS)

Carlson, David; Hsieh, Ya-Ping; Collins, Edo; Carin, Lawrence; Cevher, Volkan

2015-01-01

Interest in deep probabilistic graphical models has in-creased in recent years, due to their state-of-the-art performance on many machine learning applications. Such models are typically trained with the stochastic gradient method, which can take a significant number of iterations to converge. Since the computational cost of gradient estimation is prohibitive even for modestly sized models, training becomes slow and practically usable models are kept small. In this paper we propose a new, largely tuning-free algorithm to address this problem. Our approach derives novel majorization bounds based on the Schatten- norm. Intriguingly, the minimizers of these bounds can be interpreted as gradient methods in a non-Euclidean space. We thus propose using a stochastic gradient method in non-Euclidean space. We both provide simple conditions under which our algorithm is guaranteed to converge, and demonstrate empirically that our algorithm leads to dramatically faster training and improved predictive ability compared to stochastic gradient descent for both directed and undirected graphical models.

Clinical and laboratory features of patients of Vietnamese descent with systemic lupus erythematosus.

Science.gov (United States)

Phan, J C; Bush, T M; Donald, F; Ward, M

1999-01-01

The prevalence rate and disease manifestations of systemic lupus erythematosus (SLE) have been noted to vary among different ethnic groups. There has been no description in the English literature of SLE in the Vietnamese population. This is the first report, which details the clinical and laboratory features as well as an estimation of the prevalence of SLE in patients with a Vietnamese ancestry living in the United States. We performed a retrospective chart review of clinical and laboratory features of patients of Vietnamese descent with SLE. The case finding was performed by a review of the rheumatology clinic records at two large teaching hospitals in Santa Clara County searching for patients with SLE with a Vietnamese surname. In addition, we recruited patients by contacting all of the rheumatologists practicing in the county. Twenty-three patients of Vietnamese descent were identified with SLE in Santa Clara County. The estimated prevalence of SLE in the patients of Vietnamese descent was 42 cases per 100 000 persons. Eighty-seven per cent of the cases were born in Vietnam. The clinical and laboratory features of SLE were similar to prior published reviews except for a relatively high prevalence of anti-RNP antibody (54%). The patients with anti-RNP antibody exhibited features of overlap syndrome. There was a high rate of exposure to tuberculosis (TB). Fifty-eight per cent of patients had a positive purified protein derivative (PPD) skin test and 27% of patients had a history of clinical TB. Forty-four per cent of patients had evidence of hepatitis B exposure. The prevalence of SLE in the Vietnamese population in Santa Clara County is similar to that of other Asian populations. There was a relatively high prevalence of anti-RNP antibody in our patient group which was associated with overlap features. As expected in an immigrant population from Southeast Asia, there was a high rate of prior exposure to tuberculosis and hepatitis B. Clinicians should diligently

Language Practices and Attitudes of Australian Children of Indian Descent in a Primary Education Setting

Science.gov (United States)

Bissoonauth, Anu

2018-01-01

This paper investigated linguistic practices and choices of Australian children of Indian descent, an under-researched group, who are studying Hindi in primary education. Data was collected using a questionnaire and semi-structured interviews with sixty participants across 3 primary schools in the Sydney area. The findings revealed, as expected,…

Sexual Health Discussions between African-American Mothers and Mothers of Latino Descent and Their Children

Science.gov (United States)

Murray, Ashley; Ellis, Monica U.; Castellanos, Ted; Gaul, Zaneta; Sutton, Madeline Y.; Sneed, Carl D.

2014-01-01

We examined approaches used by African-American mothers and mothers of Latino descent for informal sex-related discussions with their children to inform sexually transmitted infection (STI)/HIV intervention development efforts. We recruited mothers (of children aged 12-15) from youth service agencies and a university in southern California.…

Programmed gradient descent biosorption of strontium ions by Saccaromyces cerevisiae and ashing analysis: A decrement solution for nuclide and heavy metal disposal

Energy Technology Data Exchange (ETDEWEB)

Liu, Mingxue [Life Science and Engineering College, Southwest University of Science and Technology, Mianyang, 621010 (China); Key Laboratory of Solid Waste Treatment and Resource Recycle, Ministry of Education of China, Mianyang, 621010 (China); Dong, Faqin, E-mail: fqdong@swust.edu.cn [Key Laboratory of Solid Waste Treatment and Resource Recycle, Ministry of Education of China, Mianyang, 621010 (China); Zhang, Wei [Key Laboratory of Solid Waste Treatment and Resource Recycle, Ministry of Education of China, Mianyang, 621010 (China); Nie, Xiaoqin [Fundamental Science on Nuclear Wastes and Environmental Safety Laboratory, Mianyang, 621010 (China); Sun, Shiyong [Key Laboratory of Solid Waste Treatment and Resource Recycle, Ministry of Education of China, Mianyang, 621010 (China); Wei, Hongfu; Luo, Lang; Xiang, Sha; Zhang, Gege [Life Science and Engineering College, Southwest University of Science and Technology, Mianyang, 621010 (China)

2016-08-15

Highlights: • A programmed gradient descent biosorption process was designed. • The adsorption and bioaccumulation quantity of strontium ions by yeast cell were measured. • The decrement of biosorbents after biosorption by ashing was analyzed. • A technological flow process of decrement solution for waste disposal was proposed. - Abstract: One of the waste disposal principles is decrement. The programmed gradient descent biosorption of strontium ions by Saccaromyces cerevisiae regarding bioremoval and ashing process for decrement were studied in present research. The results indicated that S. cerevisiae cells showed valid biosorption for strontium ions with greater than 90% bioremoval efficiency for high concentration strontium ions under batch culture conditions. The S. cerevisiae cells bioaccumulated approximately 10% of strontium ions in the cytoplasm besides adsorbing 90% strontium ions on cell wall. The programmed gradient descent biosorption presented good performance with a nearly 100% bioremoval ratio for low concentration strontium ions after 3 cycles. The ashing process resulted in a huge volume and weight reduction ratio as well as enrichment for strontium in the ash. XRD results showed that SrSO{sub 4} existed in ash. Simulated experiments proved that sulfate could adjust the precipitation of strontium ions. Finally, we proposed a technological flow process that combined the programmed gradient descent biosorption and ashing, which could yield great decrement and allow the supernatant to meet discharge standard. This technological flow process may be beneficial for nuclides and heavy metal disposal treatment in many fields.

Superspace descent equations and zero curvature formalism of the four dimensional N=1 supersymmetric Yang-Mills theories

International Nuclear Information System (INIS)

Vilar, L.C.Q.; Sasaki, C.A.G.; Sorella, S.P.

1996-09-01

The supersymmetric descent equations in superspace are discussed by means of the introduction of two operators ζ α , ζ -α which allow to decompose the supersymmetric covariant derivatives D α , D -α as BRS commutators. (author). 27 refs., 4 tabs

Human Mars Entry, Descent, and Landing Architecture Study Overview

Science.gov (United States)

Cianciolo, Alicia D.; Polsgrove, Tara T.

2016-01-01

The Entry, Descent, and Landing (EDL) Architecture Study is a multi-NASA center activity to analyze candidate EDL systems as they apply to human Mars landing in the context of the Evolvable Mars Campaign. The study, led by the Space Technology Mission Directorate (STMD), is performed in conjunction with the NASA's Science Mission Directorate and the Human Architecture Team, sponsored by NASA's Human Exploration and Operations Mission Directorate. The primary objective is to prioritize future STMD EDL technology investments by (1) generating Phase A-level designs for selected concepts to deliver 20 t human class payloads, (2) developing a parameterized mass model for each concept capable of examining payloads between 5 and 40 t, and (3) evaluating integrated system performance using trajectory simulations. This paper summarizes the initial study results.

Accelerated convergence of the steepest-descent method for magnetohydrodynamic equilibria

International Nuclear Information System (INIS)

Handy, C.R.; Hirshman, S.P.

1984-06-01

Iterative schemes based on the method of steepest descent have recently been used to obtain magnetohydrodynamic (MHD) equilibria. Such schemes generate asymptotic geometric vector sequences whose convergence rate can be improved through the use of the epsilon-algorithm. The application of this nonlinear recursive technique to stiff systems is discussed. In principle, the epsilon-algorithm is capable of yielding quadratic convergence and therefore represents an attractive alternative to other quadratic convergence schemes requiring Jacobian matrix inversion. Because the damped MHD equations have eigenvalues with negative real parts (in the neighborhood of a stable equilibrium), the epsilon-algorithm will generally be stable. Concern for residual monotonic sequences leads to consideration of alternative methods for implementing the algorithm

Effects of the Phoenix Lander descent thruster plume on the Martian surface

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Plemmons, D. H.; Mehta, M.; Clark, B. C.; Kounaves, S. P.; Peach, L. L.; Renno, N. O.; Tamppari, L.; Young, S. M. M.

2008-08-01

The exhaust plume of Phoenix's hydrazine monopropellant pulsed descent thrusters will impact the surface of Mars during its descent and landing phase in the northern polar region. Experimental and computational studies have been performed to characterize the chemical compounds in the thruster exhausts. No undecomposed hydrazine is observed above the instrument detection limit of 0.2%. Forty-five percent ammonia is measured in the exhaust at steady state. Water vapor is observed at a level of 0.25%, consistent with fuel purity analysis results. Moreover, the dynamic interactions of the thruster plumes with the ground have been studied. Large pressure overshoots are produced at the ground during the ramp-up and ramp-down phases of the duty cycle of Phoenix's pulsed engines. These pressure overshoots are superimposed on the 10 Hz quasi-steady ground pressure perturbations with amplitude of about 5 kPa (at touchdown altitude) and have a maximum amplitude of about 20-40 kPa. A theoretical explanation for the physics that causes these pressure perturbations is briefly described in this article. The potential for soil erosion and uplifting at the landing site is also discussed. The objectives of the research described in this article are to provide empirical and theoretical data for the Phoenix Science Team to mitigate any potential problem. The data will also be used to ensure proper interpretation of the results from on-board scientific instrumentation when Martian soil samples are analyzed.

Superspace descent equations and zero curvature formalism of the four dimensional N=1 supersymmetric Yang-Mills theories

Energy Technology Data Exchange (ETDEWEB)

Vilar, L.C.Q.; Sasaki, C.A.G. [Centro Brasileiro de Pesquisas Fisicas (CBPF), Rio de Janeiro, RJ (Brazil); Sorella, S.P. [Universidade do Estado, Rio de Janeiro, RJ (Brazil). Inst. de Fisica

1996-09-01

The supersymmetric descent equations in superspace are discussed by means of the introduction of two operators {zeta}{sup {alpha}}, {zeta}{sup -{alpha}} which allow to decompose the supersymmetric covariant derivatives D{sup {alpha}}, D{sup -{alpha}} as BRS commutators. (author). 27 refs., 4 tabs.

Testing the Structural Invariance of the Africultural Coping Systems Inventory Across Three Samples of African Descent Populations

Science.gov (United States)

Utsey, Shawn O.; Brown, Christa; Bolden, Mark A.

2004-01-01

Confirmatory factor analysis was used to test the factorial invariance of the Africultural Coping Systems Inventory's (ACSI) measurement model and underlying factor structure across three independent and ethnically distinct samples of African descent populations. Results indicated that factor pattern coefficients of the ACSI's underlying…

The influence of acculturation and breast cancer-specific distress on perceived barriers to genetic testing for breast cancer among women of African descent.

Science.gov (United States)

Sussner, Katarina M; Thompson, Hayley S; Jandorf, Lina; Edwards, Tiffany A; Forman, Andrea; Brown, Karen; Kapil-Pair, Nidhi; Bovbjerg, Dana H; Schwartz, Marc D; Valdimarsdottir, Heiddis B

2009-09-01

Rising health disparities are increasingly evident in relation to use of genetic services (including genetic counseling and testing) for breast cancer risk, with women of African descent less likely to use genetic services compared with Whites. Meanwhile, little is known regarding potential within-group acculturation and psychological differences underlying perceived barriers to genetic testing among women of African descent. Hypothesized contributions of acculturation factors and breast cancer-specific distress to perceived barriers to genetic testing were examined with a statistical analysis of baseline data from 146 women of African descent (56% US born and 44% foreign born) meeting genetic breast cancer risk criteria and participating in a larger longitudinal study that included the opportunity for free genetic counseling and testing. Perceived barriers assessed included: (1) anticipation of negative emotional reactions, (2) stigma, (3) confidentiality concerns, (4) family-related worry, and (5) family-related guilt associated with genetic testing. In multivariate analyses, being foreign born was a significant predictor of anticipated negative emotional reactions about genetic testing (beta=0.26; SE=0.11; p=0.01). Breast cancer-specific distress scores (avoidance symptoms) were positively related to anticipated negative emotional reactions (beta=0.02; SE=0.005; p=barriers to genetic testing among women of African descent. The potential utility of culturally tailored genetic counseling services taking into account such influences and addressing emotional and psychological concerns of women considering genetic testing for breast cancer should be investigated.

Gender difference in older adult's utilization of gravitational and ground reaction force in regulation of angular momentum during stair descent.

Science.gov (United States)

Singhal, Kunal; Kim, Jemin; Casebolt, Jeffrey; Lee, Sangwoo; Han, Ki-Hoon; Kwon, Young-Hoo

2015-06-01

Angular momentum of the body is a highly controlled quantity signifying stability, therefore, it is essential to understand its regulation during stair descent. The purpose of this study was to investigate how older adults use gravity and ground reaction force to regulate the angular momentum of the body during stair descent. A total of 28 participants (12 male and 16 female; 68.5 years and 69.0 years of mean age respectively) performed stair descent from a level walk in a step-over-step manner at a self-selected speed over a custom made three-step staircase with embedded force plates. Kinematic and force data were used to calculate angular momentum, gravitational moment, and ground reaction force moment about the stance foot center of pressure. Women show a significantly greater change in normalized angular momentum (0.92Nms/Kgm; p=.004) as compared to men (0.45Nms/Kgm). Women produce higher normalized GRF (p=.031) during the double support phase. The angular momentum changes show largest backward regulation for Step 0 and forward regulation for Step 2. This greater difference in overall change in the angular momentum in women may explain their increased risk of fall over the stairs. Copyright © 2015 Elsevier B.V. All rights reserved.

Effects of environmental changes in a stair climbing intervention: generalization to stair descent.

Science.gov (United States)

Webb, Oliver J; Eves, Frank F

2007-01-01

Visual improvements have been shown to encourage stair use in worksites independently of written prompts. This study examined whether visual modifications alone can influence behavior in a shopping mall. Climbing one flight of stairs, however, will not confer health benefits. Therefore, this study also assessed whether exposure to the intervention encouraged subsequent stair use. Interrupted time-series design. Escalators flanked by a staircase on either side. Ascending and descending pedestrians (N = 81,948). Following baseline monitoring, a colorful design was introduced on the stair risers of one staircase (the target staircase). A health promotion message was superimposed later on top. The intervention was visible only to ascending pedestrians. Thus, any rise in descending stair use would indicate increased intention to use stairs, which endured after initial exposure to the intervention. Observers inconspicuously coded pedestrians' means of ascent/descent and demographic characteristics. The design alone had no meaningful impact. Addition of the message, however, increased stair climbing at the target and nontarget staircases by 190% and 52%, respectively. The message also produced a modest increase in stair descent at the target (25%) and nontarget (9%) staircases. In public venues, a message component is critical to the success of interventions. In addition, it appears that exposure to an intervention can encourage pedestrians to use stairs on a subsequent occasion.

Mothers' and Fathers' Questions to Their Child in Mexican-Descent Families: Moderators of Cognitive Demand during Play.

Science.gov (United States)

Tenenbaum, Harriet R.; Leaper, Campbell

1997-01-01

The cognitive demand in questions directed to Mexican-descent children by their mothers and fathers were analyzed for videotaped play situations involving gender-neutral, masculine-, or feminine-stereotyped toys. Mothers asked proportionately more conceptual questions than did fathers. Mothers' question asking was influenced by child gender,…

Implementasi Jaringan Syaraf Tiruan Recurrent Menggunakan Gradient Descent Adaptive Learning Rate and Momentum Untuk Pendugaan Curah Hujan

Directory of Open Access Journals (Sweden)

Afan Galih Salman

2011-06-01

Full Text Available The artificial neural network (ANN technology in rainfall prediction can be done using the learning approach. The ANN prediction accuracy is measured by the determination coefficient (R2 and root mean square error (RMSE. This research implements Elman’s Recurrent ANN which is heuristically optimized based on el-nino southern oscilation (ENSO variables: wind, southern oscillation index (SOI, sea surface temperatur (SST dan outgoing long wave radiation (OLR to forecast regional monthly rainfall in Bongan Bali. The heuristic learning optimization done is basically a performance development of standard gradient descent learning algorithm into training algorithms: gradient descent momentum and adaptive learning rate. The patterns of input data affect the performance of Recurrent Elman neural network in estimation process. The first data group that is 75% training data and 25% testing data produce the maximum R2 leap 74,6% while the second data group that is 50% training data and 50% testing data produce the maximum R2 leap 49,8%.

Modifications of Steepest Descent Method and Conjugate Gradient Method Against Noise for Ill-posed Linear Systems

Directory of Open Access Journals (Sweden)

Chein-Shan Liu

2012-04-01

Full Text Available It is well known that the numerical algorithms of the steepest descent method (SDM, and the conjugate gradient method (CGM are effective for solving well-posed linear systems. However, they are vulnerable to noisy disturbance for solving ill-posed linear systems. We propose the modifications of SDM and CGM, namely the modified steepest descent method (MSDM, and the modified conjugate gradient method (MCGM. The starting point is an invariant manifold defined in terms of a minimum functional and a fictitious time-like variable; however, in the final stage we can derive a purely iterative algorithm including an acceleration parameter. Through the Hopf bifurcation, this parameter indeed plays a major role to switch the situation of slow convergence to a new situation that the functional is stepwisely decreased very fast. Several numerical examples are examined and compared with exact solutions, revealing that the new algorithms of MSDM and MCGM have good computational efficiency and accuracy, even for the highly ill-conditioned linear equations system with a large noise being imposed on the given data.

Empirical analysis of the effect of descent flight path angle on primary gaseous emissions of commercial aircraft.

Science.gov (United States)

Turgut, Enis T; Usanmaz, Oznur; Rosen, Marc A

2018-05-01

In this study, the effects of descent flight path angle (between 1.25° and 4.25°) on aircraft gaseous emissions (carbon monoxide, total hydrocarbons and nitrogen oxides) are explored using actual flight data from aircraft flight data recording system and emissions indices from the International Civil Aviation Organization. All emissions parameters are corrected to flight conditions using Boeing Fuel Flow Method2, where the ambient air pressure, temperature and humidity data are obtained from long-term radiosonde data measured close to the arrival airport. The main findings highlight that the higher the flight path angle, the higher the emission indices of CO and HC, whereas the lower the emissions index of NO x and fuel consumption. Furthermore, during a descent, a heavier aircraft tends to emit less CO and HC, and more NO x . For a five-tonne aircraft mass increase, the average change in emissions indices are found to be -4.1% and -5.7% (CO), -5.4% and -8.2% (HC), and +1.1% and +1.6% (NO x ) for high and low flight path angle groups, respectively. The average emissions indices for CO, HC and NO x during descent are calculated to be 24.5, 1.7 and 5.6 g/kg of fuel, whereas the average emissions for descending from 32,000 ft (9.7 km) and 24,000 ft (7.3 km) are calculated to be 7-8 kg (CO), ∼0.5 kg (HC) and ∼3 kg (NO x ). Copyright © 2018 Elsevier Ltd. All rights reserved.

Assumption-free estimation of heritability from genome-wide identity-by-descent sharing between full siblings.

Directory of Open Access Journals (Sweden)

2006-03-01

Full Text Available The study of continuously varying, quantitative traits is important in evolutionary biology, agriculture, and medicine. Variation in such traits is attributable to many, possibly interacting, genes whose expression may be sensitive to the environment, which makes their dissection into underlying causative factors difficult. An important population parameter for quantitative traits is heritability, the proportion of total variance that is due to genetic factors. Response to artificial and natural selection and the degree of resemblance between relatives are all a function of this parameter. Following the classic paper by R. A. Fisher in 1918, the estimation of additive and dominance genetic variance and heritability in populations is based upon the expected proportion of genes shared between different types of relatives, and explicit, often controversial and untestable models of genetic and non-genetic causes of family resemblance. With genome-wide coverage of genetic markers it is now possible to estimate such parameters solely within families using the actual degree of identity-by-descent sharing between relatives. Using genome scans on 4,401 quasi-independent sib pairs of which 3,375 pairs had phenotypes, we estimated the heritability of height from empirical genome-wide identity-by-descent sharing, which varied from 0.374 to 0.617 (mean 0.498, standard deviation 0.036. The variance in identity-by-descent sharing per chromosome and per genome was consistent with theory. The maximum likelihood estimate of the heritability for height was 0.80 with no evidence for non-genetic causes of sib resemblance, consistent with results from independent twin and family studies but using an entirely separate source of information. Our application shows that it is feasible to estimate genetic variance solely from within-family segregation and provides an independent validation of previously untestable assumptions. Given sufficient data, our new paradigm will

A combinatorial and probabilistic study of initial and end heights of descents in samples of geometrically distributed random variables and in permutations

Directory of Open Access Journals (Sweden)

Helmut Prodinger

2007-01-01

Full Text Available In words, generated by independent geometrically distributed random variables, we study the l th descent, which is, roughly speaking, the l th occurrence of a neighbouring pair ab with a>b. The value a is called the initial height, and b the end height. We study these two random variables (and some similar ones by combinatorial and probabilistic tools. We find in all instances a generating function Ψ(v,u, where the coefficient of v j u i refers to the j th descent (ascent, and i to the initial (end height. From this, various conclusions can be drawn, in particular expected values. In the probabilistic part, a Markov chain model is used, which allows to get explicit expressions for the heights of the second descent. In principle, one could go further, but the complexity of the results forbids it. This is extended to permutations of a large number of elements. Methods from q-analysis are used to simplify the expressions. This is the reason that we confine ourselves to the geometric distribution only. For general discrete distributions, no such tools are available.

Frequency-domain full-waveform inversion with non-linear descent directions

Science.gov (United States)

Geng, Yu; Pan, Wenyong; Innanen, Kristopher A.

2018-05-01

Full-waveform inversion (FWI) is a highly non-linear inverse problem, normally solved iteratively, with each iteration involving an update constructed through linear operations on the residuals. Incorporating a flexible degree of non-linearity within each update may have important consequences for convergence rates, determination of low model wavenumbers and discrimination of parameters. We examine one approach for doing so, wherein higher order scattering terms are included within the sensitivity kernel during the construction of the descent direction, adjusting it away from that of the standard Gauss-Newton approach. These scattering terms are naturally admitted when we construct the sensitivity kernel by varying not the current but the to-be-updated model at each iteration. Linear and/or non-linear inverse scattering methodologies allow these additional sensitivity contributions to be computed from the current data residuals within any given update. We show that in the presence of pre-critical reflection data, the error in a second-order non-linear update to a background of s0 is, in our scheme, proportional to at most (Δs/s0)3 in the actual parameter jump Δs causing the reflection. In contrast, the error in a standard Gauss-Newton FWI update is proportional to (Δs/s0)2. For numerical implementation of more complex cases, we introduce a non-linear frequency-domain scheme, with an inner and an outer loop. A perturbation is determined from the data residuals within the inner loop, and a descent direction based on the resulting non-linear sensitivity kernel is computed in the outer loop. We examine the response of this non-linear FWI using acoustic single-parameter synthetics derived from the Marmousi model. The inverted results vary depending on data frequency ranges and initial models, but we conclude that the non-linear FWI has the capability to generate high-resolution model estimates in both shallow and deep regions, and to converge rapidly, relative to a

Hybrid Steepest-Descent Methods for Triple Hierarchical Variational Inequalities

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L. C. Ceng

2015-01-01

Full Text Available We introduce and analyze a relaxed iterative algorithm by combining Korpelevich’s extragradient method, hybrid steepest-descent method, and Mann’s iteration method. We prove that, under appropriate assumptions, the proposed algorithm converges strongly to a common element of the fixed point set of infinitely many nonexpansive mappings, the solution set of finitely many generalized mixed equilibrium problems (GMEPs, the solution set of finitely many variational inclusions, and the solution set of general system of variational inequalities (GSVI, which is just a unique solution of a triple hierarchical variational inequality (THVI in a real Hilbert space. In addition, we also consider the application of the proposed algorithm for solving a hierarchical variational inequality problem with constraints of finitely many GMEPs, finitely many variational inclusions, and the GSVI. The results obtained in this paper improve and extend the corresponding results announced by many others.

Adapting Mars Entry, Descent and Landing System for Earth

Science.gov (United States)

Heilimo, J.; Harri, A.-M.; Aleksashkin, S.; Koryanov, V.; Guerrero, H.; Schmidt, W.; Haukka, H.; Finchenko, V.; Martynov, M.; Ostresko, B.; Ponomarenko, A.; Kazakovtsev, V.; Arruego, I.; Martin, S.; Siili, T.

2013-09-01

In 2001 - 2011 an inflatable Entry, Descent and Landing System (EDLS) for Martian atmosphere was developed by FMI and the MetNet team. This MetNet Mars Lander EDLS is used in both the initial deceleration during atmospheric entry and in the final deceleration before the semi-hard impact of the penetrator to Martian surface. The EDLS design is ingenious and its applicability to Earth's atmosphere is studied in the on-going project. In particular, the behavior of the system in the critical transonic aerodynamic (from hypersonic to subsonic) regime will be investigated. This project targets to analyze and test the transonic behavior of this compact and light weight payload entry system to Earth's atmosphere [1]. Scaling and adaptation for terrestrial atmospheric conditions, instead of a completely new design, is a favorable approach for providing a new re-entry vehicle for terrestrial space applications.

Testosterone secretion during gubernacular development and testicular descent in the dog.

Science.gov (United States)

Baumans, V; Dieleman, S J; Wouterse, H S; van Tol, L; Dijkstra, G; Wensing, C J

1985-01-01

Serum testosterone concentrations ranged from 0.24 to 1.45 nmol/l between Day 53 post coitum (p.c.) until Day 40 post partum (p.p.) and did not show variations that could be correlated with the process of testicular descent. The intratesticular androgen appeared to be mainly testosterone, its concentration being about 5000-fold higher than that in serum whereas 5 alpha-dihydrotestosterone could not be demonstrated. The intratesticular testosterone concentration at the initiation of gubernacular regression (Day 0) was apparently, but not significantly, higher than at Day 49 p.c. and at Day 40 p.p. The ability of the neonatal canine testis to synthesize testosterone was indicated by increased serum testosterone concentrations after hCG stimulation.

Sufficient Descent Polak-Ribière-Polyak Conjugate Gradient Algorithm for Large-Scale Box-Constrained Optimization

Directory of Open Access Journals (Sweden)

Qiuyu Wang

2014-01-01

descent method at first finite number of steps and then by conjugate gradient method subsequently. Under some appropriate conditions, we show that the algorithm converges globally. Numerical experiments and comparisons by using some box-constrained problems from CUTEr library are reported. Numerical comparisons illustrate that the proposed method is promising and competitive with the well-known method—L-BFGS-B.

Sparse Nonlinear Electromagnetic Imaging Accelerated With Projected Steepest Descent Algorithm

KAUST Repository

Desmal, Abdulla

2017-04-03

An efficient electromagnetic inversion scheme for imaging sparse 3-D domains is proposed. The scheme achieves its efficiency and accuracy by integrating two concepts. First, the nonlinear optimization problem is constrained using L₀ or L₁-norm of the solution as the penalty term to alleviate the ill-posedness of the inverse problem. The resulting Tikhonov minimization problem is solved using nonlinear Landweber iterations (NLW). Second, the efficiency of the NLW is significantly increased using a steepest descent algorithm. The algorithm uses a projection operator to enforce the sparsity constraint by thresholding the solution at every iteration. Thresholding level and iteration step are selected carefully to increase the efficiency without sacrificing the convergence of the algorithm. Numerical results demonstrate the efficiency and accuracy of the proposed imaging scheme in reconstructing sparse 3-D dielectric profiles.

Momentum and Stochastic Momentum for Stochastic Gradient, Newton, Proximal Point and Subspace Descent Methods

KAUST Repository

Loizou, Nicolas

2017-12-27

In this paper we study several classes of stochastic optimization algorithms enriched with heavy ball momentum. Among the methods studied are: stochastic gradient descent, stochastic Newton, stochastic proximal point and stochastic dual subspace ascent. This is the first time momentum variants of several of these methods are studied. We choose to perform our analysis in a setting in which all of the above methods are equivalent. We prove global nonassymptotic linear convergence rates for all methods and various measures of success, including primal function values, primal iterates (in L2 sense), and dual function values. We also show that the primal iterates converge at an accelerated linear rate in the L1 sense. This is the first time a linear rate is shown for the stochastic heavy ball method (i.e., stochastic gradient descent method with momentum). Under somewhat weaker conditions, we establish a sublinear convergence rate for Cesaro averages of primal iterates. Moreover, we propose a novel concept, which we call stochastic momentum, aimed at decreasing the cost of performing the momentum step. We prove linear convergence of several stochastic methods with stochastic momentum, and show that in some sparse data regimes and for sufficiently small momentum parameters, these methods enjoy better overall complexity than methods with deterministic momentum. Finally, we perform extensive numerical testing on artificial and real datasets, including data coming from average consensus problems.

Momentum and Stochastic Momentum for Stochastic Gradient, Newton, Proximal Point and Subspace Descent Methods

KAUST Repository

Loizou, Nicolas; Richtarik, Peter

2017-01-01

In this paper we study several classes of stochastic optimization algorithms enriched with heavy ball momentum. Among the methods studied are: stochastic gradient descent, stochastic Newton, stochastic proximal point and stochastic dual subspace ascent. This is the first time momentum variants of several of these methods are studied. We choose to perform our analysis in a setting in which all of the above methods are equivalent. We prove global nonassymptotic linear convergence rates for all methods and various measures of success, including primal function values, primal iterates (in L2 sense), and dual function values. We also show that the primal iterates converge at an accelerated linear rate in the L1 sense. This is the first time a linear rate is shown for the stochastic heavy ball method (i.e., stochastic gradient descent method with momentum). Under somewhat weaker conditions, we establish a sublinear convergence rate for Cesaro averages of primal iterates. Moreover, we propose a novel concept, which we call stochastic momentum, aimed at decreasing the cost of performing the momentum step. We prove linear convergence of several stochastic methods with stochastic momentum, and show that in some sparse data regimes and for sufficiently small momentum parameters, these methods enjoy better overall complexity than methods with deterministic momentum. Finally, we perform extensive numerical testing on artificial and real datasets, including data coming from average consensus problems.

The technology applying of inflatable devices to access adaptation, movement and landing descent vehicle from Martian environment to the Earth conditions

Science.gov (United States)

Koryanov, Vsevolod V.; Kazakovtsev, Victor P.

2017-07-01

At present, the idea has emerged to use special inflatable braking device (IBD) which permits to implement the landing vehicle (LV) "soft" landing on the planet's surface without a parachute system. Braking device (BD) unfolds still at the extra-atmospheric flight stage to provide the LV passive stabilisation, and the entire apparatus together with the braking device is twisted around its longitudinal axis. The advantage of an inflatable BD over traditional non-rigid brakes - parachutes is that it can be used at the atmospheric stage of the descent, starting from hypersonic speeds, and ending subsonic ones. These main theses are implemented in the project MetNet and its sequel project RITD, using Entry, Descent and Landing System (EDLS) system [1].

A coordinate descent MM algorithm for fast computation of sparse logistic PCA

KAUST Repository

Lee, Seokho

2013-06-01

Sparse logistic principal component analysis was proposed in Lee et al. (2010) for exploratory analysis of binary data. Relying on the joint estimation of multiple principal components, the algorithm therein is computationally too demanding to be useful when the data dimension is high. We develop a computationally fast algorithm using a combination of coordinate descent and majorization-minimization (MM) auxiliary optimization. Our new algorithm decouples the joint estimation of multiple components into separate estimations and consists of closed-form elementwise updating formulas for each sparse principal component. The performance of the proposed algorithm is tested using simulation and high-dimensional real-world datasets. © 2013 Elsevier B.V. All rights reserved.

Quantification of Plume-Soil Interaction and Excavation Due to the Sky Crane Descent Stage

Science.gov (United States)

Vizcaino, Jeffrey; Mehta, Manish

2015-01-01

The quantification of the particulate erosion that occurs as a result of a rocket exhaust plume impinging on soil during extraterrestrial landings is critical for future robotic and human lander mission design. The aerodynamic environment that results from the reflected plumes results in dust lifting, site alteration and saltation, all of which create a potentially erosive and contaminant heavy environment for the lander vehicle and any surrounding structures. The Mars Science Lab (MSL), weighing nearly one metric ton, required higher levels of thrust from its retro propulsive systems and an entirely new descent system to minimize these effects. In this work we seek to quantify plume soil interaction and its resultant soil erosion caused by the MSL's Sky Crane descent stage engines by performing three dimensional digital terrain and elevation mapping of the Curiosity rover's landing site. Analysis of plume soil interaction altitude and time was performed by detailed examination of the Mars Descent Imager (MARDI) still frames and reconstructed inertial measurement unit (IMU) sensor data. Results show initial plume soil interaction from the Sky Crane's eight engines began at ground elevations greater than 60 meters and more than 25 seconds before the rovers' touchdown event. During this time, viscous shear erosion (VSE) was dominant typically resulting in dusting of the surface with flow propagating nearly parallel to the surface. As the vehicle descended and decreased to four powered engines plume-plume and plume soil interaction increased the overall erosion rate at the surface. Visibility was greatly reduced at a height of roughly 20 meters above the surface and fell to zero ground visibility shortly after. The deployment phase of the Sky Crane descent stage hovering at nearly six meters above the surface showed the greatest amount of erosion with several large particles of soil being kicked up, recirculated, and impacting the bottom of the rover chassis. Image

Spacecraft Trajectory Generation by Successive Approximation for Powered Descent and Cyclers

Science.gov (United States)

Casoliva, Jordi

Methods for spacecraft trajectory generation must be reliable. Complex nonlinear dynamics and constraints impede straightforward approaches. The approach pursued in this dissertation is to use successive approximation, which entails solving a sequence of problems, each one of which can be solved reliably, leading to the solution of the problem of interest. First, contractive sequential convex programming (CSCP) is developed and then applied to the problem of optimal powered descent landing in the presence of complex constraints, aerodynamic force and nonlinear engine performance. Second, numerical continuation is applied to the generation of cycler (periodic) spacecraft trajectories in the Earth-Moon system, the challenge here being the multiple scales of the three-body dynamics. The first-order necessary conditions for minimum-fuel powered descent are derived and interpreted. Both a point-mass model with throttle and thrust angle control and a rigid-body model with throttle and angular velocity control are considered, with a more complete analysis of the rigid-body case than previously available in the literature. The effects of boundary conditions on the thrust direction and finite bounds on the angular velocities are analyzed for the rigid-body case. Minimum-fuel solutions, obtained numerically, illustrate the optimal strategies. The optimal powered descent landing problem considered in the development of CSCP has a convex cost function, nonlinear dynamics, convex state constraints and nonlinear non-convex control constraints. The non-convexity in the control constraints is handled with the lossless convexification technique which consists of a convex relaxation on the control constraints. The novelty of CSCP is the ability to account for nonlinear dynamics and nonlinear control bounds in the optimal control problem and the use of interior-point methods for second-order cone programs which are guaranteed to find the optimal solution. CSCP solves a convergent

Applying Gradient Descent in Convolutional Neural Networks

Science.gov (United States)

Cui, Nan

2018-04-01

With the development of the integrated circuit and computer science, people become caring more about solving practical issues via information technologies. Along with that, a new subject called Artificial Intelligent (AI) comes up. One popular research interest of AI is about recognition algorithm. In this paper, one of the most common algorithms, Convolutional Neural Networks (CNNs) will be introduced, for image recognition. Understanding its theory and structure is of great significance for every scholar who is interested in this field. Convolution Neural Network is an artificial neural network which combines the mathematical method of convolution and neural network. The hieratical structure of CNN provides it reliable computer speed and reasonable error rate. The most significant characteristics of CNNs are feature extraction, weight sharing and dimension reduction. Meanwhile, combining with the Back Propagation (BP) mechanism and the Gradient Descent (GD) method, CNNs has the ability to self-study and in-depth learning. Basically, BP provides an opportunity for backwardfeedback for enhancing reliability and GD is used for self-training process. This paper mainly discusses the CNN and the related BP and GD algorithms, including the basic structure and function of CNN, details of each layer, the principles and features of BP and GD, and some examples in practice with a summary in the end.

Severe G6PD Deficiency Due to a New Missense Mutation in an Infant of Northern European Descent

DEFF Research Database (Denmark)

Warny, Marie; Lausen, Birgitte; Birgens, Henrik

2015-01-01

We report a term male infant born to parents of Danish descent, who on the second day of life developed jaundice peaking at 67 hours and decreasing on applied double-sided phototherapy. In the weeks following, the infant showed signs of ongoing hemolysis. Laboratory tests showed very low glucose-6...

"Arubaito," or Short-Term Working Abroad in Japan: A Case Study of Brazilian University Students of Japanese Descent

Science.gov (United States)

Sasaki, Lindsey

2012-01-01

International migration between Japan and Brazil dates back to 1908, when the first group of Japanese migrated to Brazil. However, in the 1980s, a reverse flow occurred, as thousands of Brazilians of Japanese descent traveled to Japan to work in manufacturing and construction factories ("dekasegi" workers). Japanese Brazilians up until…

Factors that Enable Women of South Asian and African Descent to Succeed in Leadership Positions in Higher Education

Science.gov (United States)

Kamassah, Sharon

2010-01-01

This research study focused on the factors that enable women of South Asian and African descent to succeed as leaders in the college system. The findings were derived from online questionnaires and in-depth interviews of 16 racialized women from two Greater Toronto Area (GTA) colleges. Many factors and recommendations were shared. Some of the…

FUSION OF MULTI-SCALE DEMS FROM DESCENT AND NAVCM IMAGES OF CHANG’E-3 USING COMPRESSED SENSING METHOD

Directory of Open Access Journals (Sweden)

M. Peng

2017-07-01

Full Text Available The multi-source DEMs generated using the images acquired in the descent and landing phase and after landing contain supplementary information, and this makes it possible and beneficial to produce a higher-quality DEM through fusing the multi-scale DEMs. The proposed fusion method consists of three steps. First, source DEMs are split into small DEM patches, then the DEM patches are classified into a few groups by local density peaks clustering. Next, the grouped DEM patches are used for sub-dictionary learning by stochastic coordinate coding. The trained sub-dictionaries are combined into a dictionary for sparse representation. Finally, the simultaneous orthogonal matching pursuit (SOMP algorithm is used to achieve sparse representation. We use the real DEMs generated from Chang’e-3 descent images and navigation camera (Navcam stereo images to validate the proposed method. Through the experiments, we have reconstructed a seamless DEM with the highest resolution and the largest spatial coverage among the input data. The experimental results demonstrated the feasibility of the proposed method.

The effect of the descent technique and truck cabin layout on the landing impact forces.

Science.gov (United States)

Patenaude, S; Marchand, D; Samperi, S; Bélanger, M

2001-12-01

The majority of injuries to truckers are caused by falls during the descent from the cab of the truck. Several studies have shown that the techniques used to descend from the truck and the layout of the truck's cabin are the principal cause of injury. The goal of the present study was to measure the effects of the descent techniques used by the trucker and the layout of the truck's cabin on the impact forces absorbed by the lower limbs and the back. Kinematic data, obtained with the aid of a video camera, were combined with the force platform data to allow for calculation of the lower limb and L5-S1 torques as well as L5-S1 compressive forces. The trucker descended from two different conventional tractor cabin layouts. Each trucker descended from cabin using either "facing the truck" (FT) or "back to the truck" (BT) techniques. The results demonstrate that the BT technique produces greater ground impact forces than the FT technique, particularly when the truck does not have a handrail. The BT technique also causes an increase in the compressive forces exerted on the back. In conclusion, the use of the FT technique along with the aids (i.e., handrails and all the steps) help lower the landing impact forces as well as the lumbosacral compressive forces.

Physics-based Entry, Descent and Landing Risk Model

Science.gov (United States)

Gee, Ken; Huynh, Loc C.; Manning, Ted

2014-01-01

A physics-based risk model was developed to assess the risk associated with thermal protection system failures during the entry, descent and landing phase of a manned spacecraft mission. In the model, entry trajectories were computed using a three-degree-of-freedom trajectory tool, the aerothermodynamic heating environment was computed using an engineering-level computational tool and the thermal response of the TPS material was modeled using a one-dimensional thermal response tool. The model was capable of modeling the effect of micrometeoroid and orbital debris impact damage on the TPS thermal response. A Monte Carlo analysis was used to determine the effects of uncertainties in the vehicle state at Entry Interface, aerothermodynamic heating and material properties on the performance of the TPS design. The failure criterion was set as a temperature limit at the bondline between the TPS and the underlying structure. Both direct computation and response surface approaches were used to compute the risk. The model was applied to a generic manned space capsule design. The effect of material property uncertainty and MMOD damage on risk of failure were analyzed. A comparison of the direct computation and response surface approach was undertaken.

A conjugate gradient method with descent properties under strong Wolfe line search

Science.gov (United States)

Zull, N.; ‘Aini, N.; Shoid, S.; Ghani, N. H. A.; Mohamed, N. S.; Rivaie, M.; Mamat, M.

2017-09-01

The conjugate gradient (CG) method is one of the optimization methods that are often used in practical applications. The continuous and numerous studies conducted on the CG method have led to vast improvements in its convergence properties and efficiency. In this paper, a new CG method possessing the sufficient descent and global convergence properties is proposed. The efficiency of the new CG algorithm relative to the existing CG methods is evaluated by testing them all on a set of test functions using MATLAB. The tests are measured in terms of iteration numbers and CPU time under strong Wolfe line search. Overall, this new method performs efficiently and comparable to the other famous methods.

Crossover study of amputee stair ascent and descent biomechanics using Genium and C-Leg prostheses with comparison to non-amputee control.

Science.gov (United States)

Lura, Derek J; Wernke, Matthew W; Carey, Stephanie L; Kahle, Jason T; Miro, Rebecca M; Highsmith, M Jason

2017-10-01

This study was a randomized crossover of stair ambulation of Transfemoral Amputees (TFAs) using the Genium and C-Leg prosthetic knees. TFAs typically have difficulty ascending and descending stairs, limiting community mobility. The objective of this study was to determine the relative efficacy of the Genium and C-Leg prostheses for stair ascent and descent, and their absolute efficacy relative to non-amputees. Twenty TFAs, and five non-amputees participated in the study. TFAs were randomized to begin the study with the Genium or C-Leg prosthesis. Informed consent was obtained from all participants prior to data collection and the study was listed on clinicaltrials.gov (#NCT01473662). After fitting, accommodation, and training, participants were asked to demonstrate their preferred gait pattern for stair ascent and descent and a step-over-step pattern if able. TFAs then switched prosthetic legs and repeated fitting, accommodation, training, and testing. An eight camera Vicon optical motion analysis system, and two AMTI force plates were used to track and analyze the participants' gait patterns, knee flexion angles, knee moment normalized by body weight, and swing time. For stair descent, no significant differences were found between prostheses. For stair ascent, Genium use resulted in: increased ability to use a step-over-step gait pattern (p=0.03), increased prosthetic side peak knee flexion (pstair ascent relative to the C-Leg, by enabling gait patterns that more closely resembled non-amputees. Copyright © 2017 Elsevier B.V. All rights reserved.

in a Family of South Indian Descent

Directory of Open Access Journals (Sweden)

Muthiah Subramanian

2015-01-01

Full Text Available Inherited channelopathies are a heterogeneous group of disorders resulting from dysfunction of ion channels in cellular membranes. They may manifest as diseases affecting skeletal muscle contraction, the conduction system of the heart, nervous system function, and vision syndromes. We describe a family of South Indian descent with hypokalemic periodic paralysis in which four members also have idiopathic generalized epilepsy. Hypokalemic periodic paralysis is a genetically heterogeneous channelopathy that has been linked to mutations in genes encoding three ion channels CACNIAS, SCN4A, and KCNJ2 predominantly. Although data on specific gene in idiopathic generalized epilepsy is relatively scarce, mutations of voltage gated sodium channel subunit genes (CACNB4 and nonsense mutations in voltage gated calcium channels (CACNA1A have been linked to idiopathic generalized epilepsy in two families. We speculate that gene mutations altering the ability of the beta subunit to interact with the alpha subunit of the CaV1.1 channel and mutations in the pore-forming potassium channel subunit may be possible explanations for the combined manifestation of both diseases. Functional analysis of voltage gated calcium channel and other ion channels mutations may provide additional support and insight for the causal role of these mutations. The understanding of mutations in ion-channel genes will lead to improved diagnosis and treatment of such inherited channelopathies.

Atmospheric Risk Assessment for the Mars Science Laboratory Entry, Descent, and Landing System

Science.gov (United States)

Chen, Allen; Vasavada, Ashwin; Cianciolo, Alicia; Barnes, Jeff; Tyler, Dan; Hinson, David; Lewis, Stephen

2010-01-01

In 2012, the Mars Science Laboratory (MSL) mission will pioneer the next generation of robotic Entry, Descent, and Landing (EDL) systems, by delivering the largest and most capable rover to date to the surface of Mars. As with previous Mars landers, atmospheric conditions during entry, descent, and landing directly impact the performance of MSL's EDL system. While the vehicle's novel guided entry system allows it to "fly out" a range of atmospheric uncertainties, its trajectory through the atmosphere creates a variety of atmospheric sensitivities not present on previous Mars entry systems and landers. Given the mission's stringent landing capability requirements, understanding the atmosphere state and spacecraft sensitivities takes on heightened importance. MSL's guided entry trajectory differs significantly from recent Mars landers and includes events that generate different atmospheric sensitivities than past missions. The existence of these sensitivities and general advancement in the state of Mars atmospheric knowledge has led the MSL team to employ new atmosphere modeling techniques in addition to past practices. A joint EDL engineering and Mars atmosphere science and modeling team has been created to identify the key system sensitivities, gather available atmospheric data sets, develop relevant atmosphere models, and formulate methods to integrate atmosphere information into EDL performance assessments. The team consists of EDL engineers, project science staff, and Mars atmospheric scientists from a variety of institutions. This paper provides an overview of the system performance sensitivities that have driven the atmosphere modeling approach, discusses the atmosphere data sets and models employed by the team as a result of the identified sensitivities, and introduces the tools used to translate atmospheric knowledge into quantitative EDL performance assessments.

Cohomological descent theory for a morphism of stacks and for equivariant derived categories

International Nuclear Information System (INIS)

Elagin, Alexei D

2011-01-01

In the paper, we find necessary and sufficient conditions under which, if X→S is a morphism of algebraic varieties (or, in a more general case, of stacks), the derived category of S can be recovered by using the tools of descent theory from the derived category of X. We show that for an action of a linearly reductive algebraic group G on a scheme X this result implies the equivalence of the derived category of G-equivariant sheaves on X and the category of objects in the derived category of sheaves on X with a given action of G on each object. Bibliography: 18 titles.

Moving In and Out of Bilingualism: Investigating Native Language Maintenance and Shift in Mexican-Descent Children. Research Report: 6.

Science.gov (United States)

Pease-Alvarez, Lucinda

A study investigated patterns and influences in Mexican-American children's Spanish language maintenance and shift toward English dominance or monolingualism. Subjects were 64 Mexican-descent children, ages 8-9, of varying immigration backgrounds (Mexican-born, U.S.-born of Mexican-born parents, U.S.-born of U.S.-born parents), and their families…

Fractional-order gradient descent learning of BP neural networks with Caputo derivative.

Science.gov (United States)

Wang, Jian; Wen, Yanqing; Gou, Yida; Ye, Zhenyun; Chen, Hua

2017-05-01

Fractional calculus has been found to be a promising area of research for information processing and modeling of some physical systems. In this paper, we propose a fractional gradient descent method for the backpropagation (BP) training of neural networks. In particular, the Caputo derivative is employed to evaluate the fractional-order gradient of the error defined as the traditional quadratic energy function. The monotonicity and weak (strong) convergence of the proposed approach are proved in detail. Two simulations have been implemented to illustrate the performance of presented fractional-order BP algorithm on three small datasets and one large dataset. The numerical simulations effectively verify the theoretical observations of this paper as well. Copyright © 2017 Elsevier Ltd. All rights reserved.

Design requirements and development of an airborne descent path definition algorithm for time navigation

Science.gov (United States)

Izumi, K. H.; Thompson, J. L.; Groce, J. L.; Schwab, R. W.

1986-01-01

The design requirements for a 4D path definition algorithm are described. These requirements were developed for the NASA ATOPS as an extension of the Local Flow Management/Profile Descent algorithm. They specify the processing flow, functional and data architectures, and system input requirements, and recommended the addition of a broad path revision (reinitialization) function capability. The document also summarizes algorithm design enhancements and the implementation status of the algorithm on an in-house PDP-11/70 computer. Finally, the requirements for the pilot-computer interfaces, the lateral path processor, and guidance and steering function are described.

Preliminary test results of a flight management algorithm for fuel conservative descents in a time based metered traffic environment. [flight tests of an algorithm to minimize fuel consumption of aircraft based on flight time

Science.gov (United States)

Knox, C. E.; Cannon, D. G.

1979-01-01

A flight management algorithm designed to improve the accuracy of delivering the airplane fuel efficiently to a metering fix at a time designated by air traffic control is discussed. The algorithm provides a 3-D path with time control (4-D) for a test B 737 airplane to make an idle thrust, clean configured descent to arrive at the metering fix at a predetermined time, altitude, and airspeed. The descent path is calculated for a constant Mach/airspeed schedule from linear approximations of airplane performance with considerations given for gross weight, wind, and nonstandard pressure and temperature effects. The flight management descent algorithms and the results of the flight tests are discussed.

Beck Depression Inventory-II: Factor Analyses with Three Groups of Midlife Women of African Descent in the Midwest, the South, and the U.S. Virgin Islands.

Science.gov (United States)

Gary, Faye A; Yarandi, Hossein; Evans, Edris; Still, Carolyn; Mickels, Prince; Hassan, Mona; Campbell, Doris; Conic, Ruzica

2018-03-01

This research encompasses a factor analysis of the Beck Depression Inventory-II (BDI-II), which involves three groups of midlife women of African descent who reside in the Midwest, the South, and the U.S. Virgin Islands. The purpose of the study was to determine the factor structure of the BDI-II when administered to a sample of women aged 40-65 of African descent who reside in the three distinct geographical regions of the United States. A correlational, descriptive design was used, and 536 women of African descent were invited to participate in face-to-face interviews that transpired in community settings. Results of the factor analysis revealed a two-factor explanation. Factor one included symptoms such as punishment feelings and pessimism (cognitive), and the second factor included symptoms such as tiredness and loss of energy (somatic-affective). The application of the Beck Depression Inventory-II among the three groups of women generated specific information about each group and common findings across the groups. Knowledge gained from the research could help to guide specific intervention programs for the three groups of women, and explicate the common approaches that could be used for the three groups.

A Block Coordinate Descent Method for Multi-Convex Optimization with Applications to Nonnegative Tensor Factorization and Completion

Science.gov (United States)

2012-08-01

Sciandrone, On the convergence of the block nonlinear Gauss - Seidel method under convex constraints , Oper. Res. Lett., 26 (2000), pp. 127–136. [23] S.P...include nonsmooth functions. Our main interest is the block coordinate descent (BCD) method of the Gauss - Seidel type, which mini- mizes F cyclically over...original objective around the current iterate . They do not use extrapolation either and only have subsequence convergence . There are examples of ri

Changes in labial capillary density on ascent to and descent from high altitude [version 1; referees: 2 approved

Directory of Open Access Journals (Sweden)

Edward Gilbert-Kawai

2016-08-01

Full Text Available Present knowledge of how the microcirculation is altered by prolonged exposure to hypoxia at high altitude is incomplete and modification of existing analytical techniques may improve our knowledge considerably. We set out to use a novel simplified method of measuring in vivo capillary density during an expedition to high altitude using a CytoCam incident dark field imaging video-microscope. The simplified method of data capture involved recording one-second images of the mucosal surface of the inner lip to reveal data about microvasculature density in ten individuals. This was done on ascent to, and descent from, high altitude. Analysis was conducted offline by two independent investigators blinded to the participant identity, testing conditions and the imaging site.  Additionally we monitored haemoglobin concentration and haematocrit data to see if we could support or refute mechanisms of altered density relating to vessel recruitment. Repeated sets of paired values were compared using Kruskall Wallis Analysis of Variance tests, whilst comparisons of values between sites was by related samples Wilcoxon Signed Rank Test. Correlation between different variables was performed using Spearman’s rank correlation coefficient, and concordance between analysing investigators using intra-class correlation coefficient. There was a significant increase in capillary density from London on ascent to high altitude; median capillaries per field of view area increased from 22.8 to 25.3 (p=0.021. There was a further increase in vessel density during the six weeks spent at altitude (25.3 to 32.5, p=0.017. Moreover, vessel density remained high on descent to Kathmandu (31.0 capillaries per field of view area, despite a significant decrease in haemoglobin concentration and haematocrit. Using a simplified technique, we have demonstrated an increase in capillary density on early and sustained exposure to hypobaric hypoxia at thigh altitude, and that this remains

Descent imager/spectral radiometer (DISR) instrument aboard the Huygens probe of Titan

Science.gov (United States)

Tomasko, Martin G.; Doose, Lyn R.; Smith, Peter H.; Fellows, C.; Rizk, B.; See, C.; Bushroe, M.; McFarlane, E.; Wegryn, E.; Frans, E.; Clark, R.; Prout, M.; Clapp, S.

1996-10-01

The Huygen's probe of the atmosphere of Saturn's moon Titan includes one optical instrument sensitive to the wavelengths of solar radiation. The goals of this investigation fall into four broad areas: 1) the measurement of the profile of solar heating to support an improved understanding of the thermal balance of Titan and the role of the greenhouse effect in maintaining Titan's temperature structure; 2) the measurement of the size, vertical distribution, and optical properties of the aerosol and cloud particles in Titan's atmosphere to support studies of the origin, chemistry, life cycles, and role in the radiation balance of Titan played by these particles; 3) the composition of the atmosphere, particularly the vertical profile of the mixing ratio of methane, a condensable constituent in Titan's atmosphere; and 4) the physical state, composition, topography, and physical processes at work in determining the nature of the surface of Titan and its interaction with Titan's atmosphere. In order to accomplish these objectives, the Descent Imager/Spectral Radiometer (DISR) instrument makes extensive use of fiber optics to bring the light from several different sets of foreoptics to a silicon CCD detector, to a pair of InGaAs linear array detectors, and to three silicon photometers. Together these detectors permit DISR to make panoramic images of the clouds and surface of Titan, to measure the spectrum of upward and downward streaming sunlight from 350 to 1700 nm at a resolving power of about 200, to measure the reflection spectrum of >= 3000 locations on the surface, to measure the brightness and polarization of the solar aureole between 4 and 30 degrees from the sun at 500 and 935 nm, to separate the direct and diffuse downward solar flux at each wavelength measured, and to measure the continuous reflection spectrum of the ground between 850 and 1600 nm using an onboard lamp in the last 100 m of the descent.

Reactive Sequencing for Autonomous Navigation Evolving from Phoenix Entry, Descent, and Landing

Science.gov (United States)

Grasso, Christopher A.; Riedel, Joseph E.; Vaughan, Andrew T.

2010-01-01

Virtual Machine Language (VML) is an award-winning advanced procedural sequencing language in use on NASA deep-space missions since 1997, and was used for the successful entry, descent, and landing (EDL) of the Phoenix spacecraft onto the surface of Mars. Phoenix EDL utilized a state-oriented operations architecture which executed within the constraints of the existing VML 2.0 flight capability, compatible with the linear "land or die" nature of the mission. The intricacies of Phoenix EDL included the planned discarding of portions of the vehicle, the complex communications management for relay through on-orbit assets, the presence of temporally indeterminate physical events, and the need to rapidly catch up four days of sequencing should a reboot of the spacecraft flight computer occur shortly before atmospheric entry. These formidable operational challenges led to new techniques for packaging and coordinating reusable sequences called blocks using one-way synchronization via VML sequencing global variable events. The coordinated blocks acted as an ensemble to land the spacecraft, while individually managing various elements in as simple a fashion as possible. This paper outlines prototype VML 2.1 flight capabilities that have evolved from the one-way synchronization techniques in order to implement even more ambitious autonomous mission capabilities. Target missions for these new capabilities include autonomous touch-and-go sampling of cometary and asteroidal bodies, lunar landing of robotic missions, and ultimately landing of crewed lunar vehicles. Close proximity guidance, navigation, and control operations, on-orbit rendezvous, and descent and landing events featured in these missions require elaborate abort capability, manifesting highly non-linear scenarios that are so complex as to overtax traditional sequencing, or even the sort of one-way coordinated sequencing used during EDL. Foreseeing advanced command and control needs for small body and lunar landing

Understanding and Optimizing Asynchronous Low-Precision Stochastic Gradient Descent

Science.gov (United States)

De Sa, Christopher; Feldman, Matthew; Ré, Christopher; Olukotun, Kunle

2018-01-01

Stochastic gradient descent (SGD) is one of the most popular numerical algorithms used in machine learning and other domains. Since this is likely to continue for the foreseeable future, it is important to study techniques that can make it run fast on parallel hardware. In this paper, we provide the first analysis of a technique called Buckwild! that uses both asynchronous execution and low-precision computation. We introduce the DMGC model, the first conceptualization of the parameter space that exists when implementing low-precision SGD, and show that it provides a way to both classify these algorithms and model their performance. We leverage this insight to propose and analyze techniques to improve the speed of low-precision SGD. First, we propose software optimizations that can increase throughput on existing CPUs by up to 11×. Second, we propose architectural changes, including a new cache technique we call an obstinate cache, that increase throughput beyond the limits of current-generation hardware. We also implement and analyze low-precision SGD on the FPGA, which is a promising alternative to the CPU for future SGD systems. PMID:29391770

Pseudocode Interpreter (Pseudocode Integrated Development Environment with Lexical Analyzer and Syntax Analyzer using Recursive Descent Parsing Algorithm

Directory of Open Access Journals (Sweden)

Christian Lester D. Gimeno

2017-11-01

Full Text Available –This research study focused on the development of a software that helps students design, write, validate and run their pseudocode in a semi Integrated Development Environment (IDE instead of manually writing it on a piece of paper.Specifically, the study aimed to develop lexical analyzer or lexer, syntax analyzer or parser using recursive descent parsing algorithm and an interpreter. The lexical analyzer reads pseudocodesource in a sequence of symbols or characters as lexemes.The lexemes are then analyzed by the lexer that matches a pattern for valid tokens and passes to the syntax analyzer or parser. The syntax analyzer or parser takes those valid tokens and builds meaningful commands using recursive descent parsing algorithm in a form of an abstract syntax tree. The generation of an abstract syntax tree is based on the specified grammar rule created by the researcher expressed in Extended Backus-Naur Form. The Interpreter takes the generated abstract syntax tree and starts the evaluation or interpretation to produce pseudocode output. The software was evaluated using white-box testing by several ICT professionals and black-box testing by several computer science students based on the International Organization for Standardization (ISO 9126 software quality standards. The overall results of the evaluation both for white-box and black-box were described as “Excellent in terms of functionality, reliability, usability, efficiency, maintainability and portability”.

Machine learning for inverse lithography: using stochastic gradient descent for robust photomask synthesis

International Nuclear Information System (INIS)

Jia, Ningning; Lam, Edmund Y

2010-01-01

Inverse lithography technology (ILT) synthesizes photomasks by solving an inverse imaging problem through optimization of an appropriate functional. Much effort on ILT is dedicated to deriving superior masks at a nominal process condition. However, the lower k 1 factor causes the mask to be more sensitive to process variations. Robustness to major process variations, such as focus and dose variations, is desired. In this paper, we consider the focus variation as a stochastic variable, and treat the mask design as a machine learning problem. The stochastic gradient descent approach, which is a useful tool in machine learning, is adopted to train the mask design. Compared with previous work, simulation shows that the proposed algorithm is effective in producing robust masks

Exploration of the Trade Space Between Unmanned Aircraft Systems Descent Maneuver Performance and Sense-and-Avoid System Performance Requirements

Science.gov (United States)

Jack, Devin P.; Hoffler, Keith D.; Johnson, Sally C.

2014-01-01

A need exists to safely integrate Unmanned Aircraft Systems (UAS) into the United States' National Airspace System. Replacing manned aircraft's see-and-avoid capability in the absence of an onboard pilot is one of the key challenges associated with safe integration. Sense-and-avoid (SAA) systems will have to achieve yet-to-be-determined required separation distances for a wide range of encounters. They will also need to account for the maneuver performance of the UAS they are paired with. The work described in this paper is aimed at developing an understanding of the trade space between UAS maneuver performance and SAA system performance requirements, focusing on a descent avoidance maneuver. An assessment of current manned and unmanned aircraft performance was used to establish potential UAS performance test matrix bounds. Then, near-term UAS integration work was used to narrow down the scope. A simulator was developed with sufficient fidelity to assess SAA system performance requirements. The simulator generates closest-point-of-approach (CPA) data from the wide range of UAS performance models maneuvering against a single intruder with various encounter geometries. Initial attempts to model the results made it clear that developing maneuver performance groups is required. Discussion of the performance groups developed and how to know in which group an aircraft belongs for a given flight condition and encounter is included. The groups are airplane, flight condition, and encounter specific, rather than airplane-only specific. Results and methodology for developing UAS maneuver performance requirements are presented for a descent avoidance maneuver. Results for the descent maneuver indicate that a minimum specific excess power magnitude can assure a minimum CPA for a given time-to-go prediction. However, smaller amounts of specific excess power may achieve or exceed the same CPA if the UAS has sufficient speed to trade for altitude. The results of this study will

The effects of the diurnal atmospheric variability on entry, descent and landing on Mars

Directory of Open Access Journals (Sweden)

Marčeta D.

2014-01-01

Full Text Available Landing on Mars is extremely challenging task due to the fact that the Martian atmosphere is the most hostile environment in the Solar system to perform the entry, descent and landing (EDL process, because it is thick enough to create substantial heating of the entry vehicle but not thick enough to reduce its velocity to the one necessary for safe landing. Beside this, the atmosphere is very dynamic mainly due to high eccentricity of the Martian orbit, obliquity of the orbital to the equatorial plane and close alignment of the winter solstice and the orbital perihelion. Although seasonal variations of atmospheric parameters are significantly larger than the diurnal, it is very important to analyze diurnal cycles as they can significantly change vertical and horizontal atmospheric profiles in very short time intervals. This can present a serious threat to missions which have very precise timings and specific requirements such as the requirement for the daytime landing to enable ground images acquisition during the descent and landing phase. A 3-degrees-of-freedom trajectory integration routine was combined with the Mars Global Reference Atmospheric Model (Mars-GRAM to identify the dependence of the EDL profiles on the diurnal cycles of atmospheric parameters throughout the Martian year. The obtained results show that the influence of the diurnal cycles is the largest at the equator and decreases relatively symmetrically towards the poles with a slightly stronger influence in the northern hemisphere. Also, there is a significant influence of the orbital position of Mars on the effect of diurnal atmospheric variations which causes that, around the orbital perihelion and winter solstice, there is some kind of inversion of the dependance of optimal entry timing on latitude of the landing site comparing to the rest of the Martian year. [Projekat Ministarstva nauke Republike Srbije, br. 176002

The Mars Science Laboratory (MSL) Mast cameras and Descent imager: Investigation and instrument descriptions

Science.gov (United States)

Malin, Michal C.; Ravine, Michael A.; Caplinger, Michael A.; Tony Ghaemi, F.; Schaffner, Jacob A.; Maki, Justin N.; Bell, James F.; Cameron, James F.; Dietrich, William E.; Edgett, Kenneth S.; Edwards, Laurence J.; Garvin, James B.; Hallet, Bernard; Herkenhoff, Kenneth E.; Heydari, Ezat; Kah, Linda C.; Lemmon, Mark T.; Minitti, Michelle E.; Olson, Timothy S.; Parker, Timothy J.; Rowland, Scott K.; Schieber, Juergen; Sletten, Ron; Sullivan, Robert J.; Sumner, Dawn Y.; Aileen Yingst, R.; Duston, Brian M.; McNair, Sean; Jensen, Elsa H.

2017-08-01

The Mars Science Laboratory Mast camera and Descent Imager investigations were designed, built, and operated by Malin Space Science Systems of San Diego, CA. They share common electronics and focal plane designs but have different optics. There are two Mastcams of dissimilar focal length. The Mastcam-34 has an f/8, 34 mm focal length lens, and the M-100 an f/10, 100 mm focal length lens. The M-34 field of view is about 20° × 15° with an instantaneous field of view (IFOV) of 218 μrad; the M-100 field of view (FOV) is 6.8° × 5.1° with an IFOV of 74 μrad. The M-34 can focus from 0.5 m to infinity, and the M-100 from 1.6 m to infinity. All three cameras can acquire color images through a Bayer color filter array, and the Mastcams can also acquire images through seven science filters. Images are ≤1600 pixels wide by 1200 pixels tall. The Mastcams, mounted on the 2 m tall Remote Sensing Mast, have a 360° azimuth and 180° elevation field of regard. Mars Descent Imager is fixed-mounted to the bottom left front side of the rover at 66 cm above the surface. Its fixed focus lens is in focus from 2 m to infinity, but out of focus at 66 cm. The f/3 lens has a FOV of 70° by 52° across and along the direction of motion, with an IFOV of 0.76 mrad. All cameras can acquire video at 4 frames/second for full frames or 720p HD at 6 fps. Images can be processed using lossy Joint Photographic Experts Group and predictive lossless compression.

Negotiating the rules of chaste behaviour : re-interpretations of the symbolic complex of virginity by young women of Moroccan descent in The Netherlands

NARCIS (Netherlands)

Buitelaar, M.W.

This article investigates what narrations on the symbolic complex of virginity in the life-stories of second-generation women of Moroccan descent in The Netherlands can tell us about the ways these women construct, maintain and combine their various social identifications. It is demonstrated that

Robust Fully Distributed Minibatch Gradient Descent with Privacy Preservation

Directory of Open Access Journals (Sweden)

Gábor Danner

2018-01-01

Full Text Available Privacy and security are among the highest priorities in data mining approaches over data collected from mobile devices. Fully distributed machine learning is a promising direction in this context. However, it is a hard problem to design protocols that are efficient yet provide sufficient levels of privacy and security. In fully distributed environments, secure multiparty computation (MPC is often applied to solve these problems. However, in our dynamic and unreliable application domain, known MPC algorithms are not scalable or not robust enough. We propose a light-weight protocol to quickly and securely compute the sum query over a subset of participants assuming a semihonest adversary. During the computation the participants learn no individual values. We apply this protocol to efficiently calculate the sum of gradients as part of a fully distributed minibatch stochastic gradient descent algorithm. The protocol achieves scalability and robustness by exploiting the fact that in this application domain a “quick and dirty” sum computation is acceptable. We utilize the Paillier homomorphic cryptosystem as part of our solution combined with extreme lossy gradient compression to make the cost of the cryptographic algorithms affordable. We demonstrate both theoretically and experimentally, based on churn statistics from a real smartphone trace, that the protocol is indeed practically viable.

An Investigation of the Facilitative and Inhibitory Variables Impacting Breast Health Care Practices in Low Socioeconomic Status Black Women of African-American and Caribbean Descent

National Research Council Canada - National Science Library

LaSorsa, Kathryn

2001-01-01

.... This will be accomplished in two separate waves. In the first wave, facilitators and barriers to breast cancer-screening participation among low-SES women of African-American and Caribbean descent will be determined through qualitative interview...

Real-life experience with hydroxyurea in sickle cell disease: A multicenter study in a cohort of patients with heterogeneous descent.

Science.gov (United States)

Rigano, Paolo; De Franceschi, Lucia; Sainati, Laura; Piga, Antonio; Piel, Frédéric B; Cappellini, Maria Domenica; Fidone, Carmelo; Masera, Nicoletta; Palazzi, Giovanni; Gianesin, Barbara; Forni, Gian Luca

2018-03-01

We conducted the first nation-wide cohort study of sickle cell disease (SCD) in Italy, a Southern European country exposed to intense recent flux migration from endemic areas for SCD. We evaluate the impact of hydroxyurea on a total of 652 pediatric and adult patients from 33 Reference Centers for SCD (mean age 24.5±15years, 51.4% males). Hydroxyurea median treatment duration was 7years (range: crisis (-34.1%, p<0.001), hospitalization (-53.2%, p<0.001), and bone necrosis (-6.9%, p<0.001). New silent cerebral infarction (SCI) occurred during treatment (+42.4%, p<0.001) but not stroke (+0.5%, p=0.572). These observations were generally consistent upon stratification for age, descent (Caucasian or African), genotype (βS/βS, βS/β 0 or βS/β + ) and duration of treatment (< or ≥10years). There were no new safety concerns observed compared to those commonly reported in the literature. Our study, conducted on a large population of patients with different descent and compound state supports the benefits of hydroxyurea therapy as a treatment option. Registered at clinical trials.gov (NCT02709681). Copyright © 2017 Elsevier Inc. All rights reserved.

A variable neighborhood descent based heuristic to solve the capacitated location-routing problem

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M. S. Jabal-Ameli

2011-01-01

Full Text Available Location-routing problem (LRP is established as a new research area in the context of location analysis. The primary concern of LRP is on locating facilities and routing of vehicles among established facilities and existing demand points. In this work, we address the capacitated LRP which arises in many practical applications within logistics and supply chain management. The objective is to minimize the overall system costs which include the fixed costs of opening depots and using vehicles at each depot site, and the variable costs associated with delivery activities. A novel heuristic is proposed which is based on variable neighborhood descent (VND algorithm to solve the resulted problem. The computational study indicates that the proposed VND based heuristic is highly competitive with the existing solution algorithms in terms of solution quality.

The glucokinase mutation p.T206P is common among MODY patients of Jewish Ashkenazi descent.

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Gozlan, Yael; Tenenbaum, Ariel; Shalitin, Shlomit; Lebenthal, Yael; Oron, Tal; Cohen, Ohad; Phillip, Moshe; Gat-Yablonski, Galia

2012-09-01

Maturity-onset diabetes of the young (MODY) is characterized by an autosomal dominant mode of inheritance; a primary defect in insulin secretion with non-ketotic hyperglycemia, age of onset under 25 yr; and lack of autoantibodies. Heterozygous mutations in glucokinase (GCK) are associated with mild fasting hyperglycemia and gestational diabetes mellitus while homozygous or compound heterozygous GCK mutations result in permanent neonatal diabetes mellitus. Given that both the Israeli-Arabic and the various Israeli-Jewish communities tend to maintain ethnic seclusion, we speculated that it would be possible to identify a relatively narrow spectrum of mutations in the Israeli population. To characterize the genetic basis of GCK-MODY in the different ethnic groups of the Israeli population. Patients with clinically identified GCK-MODY and their first degree family members. Molecular analysis of GCK was performed on genomic DNA using polymerase chain reaction, denaturing gradient gel electrophoresis (DGGE), and sequencing. Bioinformatic model was preformed using the NEST program. Mutations in GCK were identified in 25 families and were all family-specific, except c.616A>C. p.T206P. This mutation was identified in six unrelated families, all patients from a Jewish-Ashkenazi descent, thus indicating an ethno-genetic correlation. A simple, fast, and relatively cheap DGGE/restriction-digestion assay was developed. The high incidence of the mutant allele in GCK-MODY patients of Jewish-Ashkenazi descent suggests a founder effect. We propose that clinically identified GCK-MODY patients of Jewish-Ashkenazi origin be first tested for this mutation. © 2011 John Wiley & Sons A/S.

Integrating Horizontal Gene Transfer and Common Descent to Depict Evolution and Contrast It with “Common Design”1

Science.gov (United States)

GUILLERMO PAZ-Y-MIÑO-C; ESPINOSA, AVELINA

2016-01-01

Horizontal gene transfer (HGT) and common descent interact in space and time. Because events of HGT co-occur with phylogenetic evolution, it is difficult to depict evolutionary patterns graphically. Tree-like representations of life’s diversification are useful, but they ignore the significance of HGT in evolutionary history, particularly of unicellular organisms, ancestors of multicellular life. Here we integrate the reticulated-tree model, ring of life, symbiogenesis whole-organism model, and eliminative pattern pluralism to represent evolution. Using Entamoeba histolytica alcohol dehydrogenase 2 (EhADH2), a bifunctional enzyme in the glycolytic pathway of amoeba, we illustrate how EhADH2 could be the product of both horizontally acquired features from ancestral prokaryotes (i.e. aldehyde dehydrogenase [ALDH] and alcohol dehydrogenase [ADH]), and subsequent functional integration of these enzymes into EhADH2, which is now inherited by amoeba via common descent. Natural selection has driven the evolution of EhADH2 active sites, which require specific amino acids (cysteine 252 in the ALDH domain; histidine 754 in the ADH domain), iron- and NAD+ as cofactors, and the substrates acetyl-CoA for ALDH and acetaldehyde for ADH. Alternative views invoking “common design” (i.e. the non-naturalistic emergence of major taxa independent from ancestry) to explain the interaction between horizontal and vertical evolution are unfounded. PMID:20021546

An Optimized Method for Terrain Reconstruction Based on Descent Images

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Xu Xinchao

2016-02-01

Full Text Available An optimization method is proposed to perform high-accuracy terrain reconstruction of the landing area of Chang’e III. First, feature matching is conducted using geometric model constraints. Then, the initial terrain is obtained and the initial normal vector of each point is solved on the basis of the initial terrain. By changing the vector around the initial normal vector in small steps a set of new vectors is obtained. By combining these vectors with the direction of light and camera, the functions are set up on the basis of a surface reflection model. Then, a series of gray values is derived by solving the equations. The new optimized vector is recorded when the obtained gray value is closest to the corresponding pixel. Finally, the optimized terrain is obtained after iteration of the vector field. Experiments were conducted using the laboratory images and descent images of Chang’e III. The results showed that the performance of the proposed method was better than that of the classical feature matching method. It can provide a reference for terrain reconstruction of the landing area in subsequent moon exploration missions.

Foot and Ankle Kinematics During Descent From Varying Step Heights.

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Gerstle, Emily E; O'Connor, Kristian; Keenan, Kevin G; Cobb, Stephen C

2017-12-01

In the general population, one-third of incidences during step negotiation occur during the transition to level walking. Furthermore, falls during curb negotiation are a common cause of injury in older adults. Distal foot kinematics may be an important factor in determining injury risk associated with transition step negotiation. The purpose of this study was to identify foot and ankle kinematics of uninjured individuals during descent from varying step heights. A 7-segment foot model was used to quantify kinematics as participants walked on a level walkway, stepped down a single step (heights: 5 cm, 15 cm, 25 cm), and continued walking. As step height increased, landing strategy transitioned from the rearfoot to the forefoot, and the rearfoot, lateral and medial midfoot, and medial forefoot became more plantar flexed. During weight acceptance, sagittal plane range of motion of the rearfoot, lateral midfoot, and medial and lateral forefoot increased as step height increased. The changes in landing strategy and distal foot function suggest a less stable ankle position at initial contact and increased demand on the distal foot at initial contact and through the weight acceptance phase of transition step negotiation as step height increases.

Estimating the degree of identity by descent in consanguineous couples.

Science.gov (United States)

Carr, Ian M; Markham, Sir Alexander F; Pena, Sérgio D J

2011-12-01

In some clinical and research settings, it is often necessary to identify the true level of "identity by descent" (IBD) between two individuals. However, as the individuals become more distantly related, it is increasingly difficult to accurately calculate this value. Consequently, we have developed a computer program that uses genome-wide SNP genotype data from related individuals to estimate the size and extent of IBD in their genomes. In addition, the software can compare a couple's IBD regions with either the autozygous regions of a relative affected by an autosomal recessive disease of unknown cause, or the IBD regions in the parents of the affected relative. It is then possible to calculate the probability of one of the couple's children suffering from the same disease. The software works by finding SNPs that exclude any possible IBD and then identifies regions that lack these SNPs, while exceeding a minimum size and number of SNPs. The accuracy of the algorithm was established by estimating the pairwise IBD between different members of a large pedigree with varying known coefficients of genetic relationship (CGR). © 2011 Wiley Periodicals, Inc.

Race, language, and mental evolution in Darwin's descent of man.

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Alter, Stephen G

2007-01-01

Charles Darwin was notoriously ambiguous in his remarks about the relationship between human evolution and biological race. He stressed the original unity of the races, yet he also helped to popularize the notion of a racial hierarchy filling the gaps between the highest anthropoids and civilized Europeans. A focus on Darwin's explanation of how humans initially evolved, however, shows that he mainly stressed not hierarchy but a version of humanity's original mental unity. In his book The Descent of Man, Darwin emphasized a substantial degree of mental development (including the incipient use of language) in the early, monogenetic phase of human evolution. This development, he argued, necessarily came before primeval man's numerical increase, geographic dispersion, and racial diversification, because only thus could one explain how that group was able to spread at the expense of rival ape-like populations. This scenario stood opposed to a new evolutionary polygenism formulated in the wake of Darwin's Origin of Species by his ostensible supporters Alfred Russel Wallace and Ernst Haeckel. Darwin judged this outlook inadequate to the task of explaining humanity's emergence. (c) 2007 Wiley Periodicals, Inc.

Does the pulse pressure in people of European, African and South Asian descent differ? A systematic review and meta-analysis of UK data

NARCIS (Netherlands)

Agyemang, C.; Bhopal, R.; Redekop, W. K.

2007-01-01

The aim of this study was to assess whether the pulse pressures (PPs) in people of African and South Asian descent differ from those of the European-origin White (henceforth, White) in the UK. A systematic literature review was carried out using MEDLINE 1966-2006 and EMBASE 1980-2006. The

Natural selection and the distribution of identity-by-descent in the human genome

DEFF Research Database (Denmark)

Albrechtsen, Anders; Moltke, Ida; Nielsen, Rasmus

2010-01-01

There has recently been considerable interest in detecting natural selection in the human genome. Selection will usually tend to increase identity-by-descent (IBD) among individuals in a population, and many methods for detecting recent and ongoing positive selection indirectly take advantage...... of this. In this article we show that excess IBD sharing is a general property of natural selection and we show that this fact makes it possible to detect several types of selection including a type that is otherwise difficult to detect: selection acting on standing genetic variation. Motivated by this......, we use a recently developed method for identifying IBD sharing among individuals from genome-wide data to scan populations from the new HapMap phase 3 project for regions with excess IBD sharing in order to identify regions in the human genome that have been under strong, very recent selection...

A Multidisciplinary Tool for Systems Analysis of Planetary Entry, Descent, and Landing (SAPE)

Science.gov (United States)

Samareh, Jamshid A.

2009-01-01

SAPE is a Python-based multidisciplinary analysis tool for systems analysis of planetary entry, descent, and landing (EDL) for Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, and Titan. The purpose of SAPE is to provide a variable-fidelity capability for conceptual and preliminary analysis within the same framework. SAPE includes the following analysis modules: geometry, trajectory, aerodynamics, aerothermal, thermal protection system, and structural sizing. SAPE uses the Python language-a platform-independent open-source software for integration and for the user interface. The development has relied heavily on the object-oriented programming capabilities that are available in Python. Modules are provided to interface with commercial and government off-the-shelf software components (e.g., thermal protection systems and finite-element analysis). SAPE runs on Microsoft Windows and Apple Mac OS X and has been partially tested on Linux.

Genetic drift. Descent, lineage, and pedigree of the Trojans in Homer's Iliad.

Science.gov (United States)

Bazopoulou-Kyrkanidou, Euterpe

2007-12-15

Homer's Iliad, is an epic poem that describes the last 70 days of the Trojan War, which was waged against the city of Troy by the Achaeans. Here, the descent, lineage, and the pedigree of the Trojans are presented. In the Illiad, they are said to have originated from Zeus. Beginning with him, the Trojan pedigree comprised 17 men in 8 generations with Dardanus, founder of Dardania in the second generation; Tros, King of the Trojans in the fourth generation; and the two heroes Hector and Aeneas in the eighth generation. In the seventh generation, Priam, as King of the Trojans, had a huge family, including 50 sons: 19 children with his wife Hecabe, other sons with many different wives, and some daughters as well. Hector, the first born, became leader of the Trojans. Hector's brother, Paris, in abducting Helen of Sparta, the wife of King Menelaus, caused the Trojan War to break out. (c) 2007 Wiley-Liss, Inc.

Do consanguineous parents of a child affected by an autosomal recessive disease have more DNA identical-by-descent than similarly-related parents with healthy offspring? Design of a case-control study

Directory of Open Access Journals (Sweden)

Cornel Martina C

2010-07-01

Full Text Available Abstract Background The offspring of consanguineous relations have an increased risk of congenital/genetic disorders and early mortality. Consanguineous couples and their offspring account for approximately 10% of the global population. The increased risk for congenital/genetic disorders is most marked for autosomal recessive disorders and depends on the degree of relatedness of the parents. For children of first cousins the increased risk is 2-4%. For individual couples, however, the extra risk can vary from zero to 25% or higher, with only a minority of these couples having an increased risk of at least 25%. It is currently not possible to differentiate between high-and low-risk couples. The quantity of DNA identical-by-descent between couples with the same degree of relatedness shows a remarkable variation. Here we hypothesize that consanguineous partners with children affected by an autosomal recessive disease have more DNA identical-by-descent than similarly-related partners who have only healthy children. The aim of the study is thus to establish whether the amount of DNA identical-by-descent in consanguineous parents of children with an autosomal recessive disease is indeed different from its proportion in consanguineous parents who have healthy children only. Methods/Design This project is designed as a case-control study. Cases are defined as consanguineous couples with one or more children with an autosomal recessive disorder and controls as consanguineous couples with at least three healthy children and no affected child. We aim to include 100 case couples and 100 control couples. Control couples are matched by restricting the search to the same family, clan or ethnic origin as the case couple. Genome-wide SNP arrays will be used to test our hypothesis. Discussion This study contains a new approach to risk assessment in consanguineous couples. There is no previous study on the amount of DNA identical-by-descent in consanguineous

A flight management algorithm and guidance for fuel-conservative descents in a time-based metered air traffic environment: Development and flight test results

Science.gov (United States)

Knox, C. E.

1984-01-01

A simple airborne flight management descent algorithm designed to define a flight profile subject to the constraints of using idle thrust, a clean airplane configuration (landing gear up, flaps zero, and speed brakes retracted), and fixed-time end conditions was developed and flight tested in the NASA TSRV B-737 research airplane. The research test flights, conducted in the Denver ARTCC automated time-based metering LFM/PD ATC environment, demonstrated that time guidance and control in the cockpit was acceptable to the pilots and ATC controllers and resulted in arrival of the airplane over the metering fix with standard deviations in airspeed error of 6.5 knots, in altitude error of 23.7 m (77.8 ft), and in arrival time accuracy of 12 sec. These accuracies indicated a good representation of airplane performance and wind modeling. Fuel savings will be obtained on a fleet-wide basis through a reduction of the time error dispersions at the metering fix and on a single-airplane basis by presenting the pilot with guidance for a fuel-efficient descent.

Understanding the Convolutional Neural Networks with Gradient Descent and Backpropagation

Science.gov (United States)

Zhou, XueFei

2018-04-01

With the development of computer technology, the applications of machine learning are more and more extensive. And machine learning is providing endless opportunities to develop new applications. One of those applications is image recognition by using Convolutional Neural Networks (CNNs). CNN is one of the most common algorithms in image recognition. It is significant to understand its theory and structure for every scholar who is interested in this field. CNN is mainly used in computer identification, especially in voice, text recognition and other aspects of the application. It utilizes hierarchical structure with different layers to accelerate computing speed. In addition, the greatest features of CNNs are the weight sharing and dimension reduction. And all of these consolidate the high effectiveness and efficiency of CNNs with idea computing speed and error rate. With the help of other learning altruisms, CNNs could be used in several scenarios for machine learning, especially for deep learning. Based on the general introduction to the background and the core solution CNN, this paper is going to focus on summarizing how Gradient Descent and Backpropagation work, and how they contribute to the high performances of CNNs. Also, some practical applications will be discussed in the following parts. The last section exhibits the conclusion and some perspectives of future work.

Risk-Constrained Dynamic Programming for Optimal Mars Entry, Descent, and Landing

Science.gov (United States)

Ono, Masahiro; Kuwata, Yoshiaki

2013-01-01

A chance-constrained dynamic programming algorithm was developed that is capable of making optimal sequential decisions within a user-specified risk bound. This work handles stochastic uncertainties over multiple stages in the CEMAT (Combined EDL-Mobility Analyses Tool) framework. It was demonstrated by a simulation of Mars entry, descent, and landing (EDL) using real landscape data obtained from the Mars Reconnaissance Orbiter. Although standard dynamic programming (DP) provides a general framework for optimal sequential decisionmaking under uncertainty, it typically achieves risk aversion by imposing an arbitrary penalty on failure states. Such a penalty-based approach cannot explicitly bound the probability of mission failure. A key idea behind the new approach is called risk allocation, which decomposes a joint chance constraint into a set of individual chance constraints and distributes risk over them. The joint chance constraint was reformulated into a constraint on an expectation over a sum of an indicator function, which can be incorporated into the cost function by dualizing the optimization problem. As a result, the chance-constraint optimization problem can be turned into an unconstrained optimization over a Lagrangian, which can be solved efficiently using a standard DP approach.

Atmosphere Assessment for MARS Science Laboratory Entry, Descent and Landing Operations

Science.gov (United States)

Cianciolo, Alicia D.; Cantor, Bruce; Barnes, Jeff; Tyler, Daniel, Jr.; Rafkin, Scot; Chen, Allen; Kass, David; Mischna, Michael; Vasavada, Ashwin R.

2013-01-01

On August 6, 2012, the Mars Science Laboratory rover, Curiosity, successfully landed on the surface of Mars. The Entry, Descent and Landing (EDL) sequence was designed using atmospheric conditions estimated from mesoscale numerical models. The models, developed by two independent organizations (Oregon State University and the Southwest Research Institute), were validated against observations at Mars from three prior years. In the weeks and days before entry, the MSL "Council of Atmospheres" (CoA), a group of atmospheric scientists and modelers, instrument experts and EDL simulation engineers, evaluated the latest Mars data from orbiting assets including the Mars Reconnaissance Orbiter's Mars Color Imager (MARCI) and Mars Climate Sounder (MCS), as well as Mars Odyssey's Thermal Emission Imaging System (THEMIS). The observations were compared to the mesoscale models developed for EDL performance simulation to determine if a spacecraft parameter update was necessary prior to entry. This paper summarizes the daily atmosphere observations and comparison to the performance simulation atmosphere models. Options to modify the atmosphere model in the simulation to compensate for atmosphere effects are also presented. Finally, a summary of the CoA decisions and recommendations to the MSL project in the days leading up to EDL is provided.

Chemokine Ligand 5 (CCL5 and chemokine receptor (CCR5 genetic variants and prostate cancer risk among men of African Descent: a case-control study

Directory of Open Access Journals (Sweden)

Kidd LaCreis R

2012-11-01

Full Text Available Abstract Background Chemokine and chemokine receptors play an essential role in tumorigenesis. Although chemokine-associated single nucleotide polymorphisms (SNPs are associated with various cancers, their impact on prostate cancer (PCA among men of African descent is unknown. Consequently, this study evaluated 43 chemokine-associated SNPs in relation to PCA risk. We hypothesized inheritance of variant chemokine-associated alleles may lead to alterations in PCA susceptibility, presumably due to variations in antitumor immune responses. Methods Sequence variants were evaluated in germ-line DNA samples from 814 African-American and Jamaican men (279 PCA cases and 535 controls using Illumina’s Goldengate genotyping system. Results Inheritance of CCL5 rs2107538 (AA, GA+AA and rs3817655 (AA, AG, AG+AA genotypes were linked with a 34-48% reduction in PCA risk. Additionally, the recessive and dominant models for CCR5 rs1799988 and CCR7 rs3136685 were associated with a 1.52-1.73 fold increase in PCA risk. Upon stratification, only CCL5 rs3817655 and CCR7 rs3136685 remained significant for the Jamaican and U.S. subgroups, respectively. Conclusions In summary, CCL5 (rs2107538, rs3817655 and CCR5 (rs1799988 sequence variants significantly modified PCA susceptibility among men of African descent, even after adjusting for age and multiple comparisons. Our findings are only suggestive and require further evaluation and validation in relation to prostate cancer risk and ultimately disease progression, biochemical/disease recurrence and mortality in larger high-risk subgroups. Such efforts will help to identify genetic markers capable of explaining disproportionately high prostate cancer incidence, mortality, and morbidity rates among men of African descent.

Managing Complexity in the MSL/Curiosity Entry, Descent, and Landing Flight Software and Avionics Verification and Validation Campaign

Science.gov (United States)

Stehura, Aaron; Rozek, Matthew

2013-01-01

The complexity of the Mars Science Laboratory (MSL) mission presented the Entry, Descent, and Landing systems engineering team with many challenges in its Verification and Validation (V&V) campaign. This paper describes some of the logistical hurdles related to managing a complex set of requirements, test venues, test objectives, and analysis products in the implementation of a specific portion of the overall V&V program to test the interaction of flight software with the MSL avionics suite. Application-specific solutions to these problems are presented herein, which can be generalized to other space missions and to similar formidable systems engineering problems.

Mars Science Laboratory (MSL) Entry, Descent, and Landing Instrumentation (MEDLI): Complete Flight Data Set

Science.gov (United States)

Cheatwood, F. McNeil; Bose, Deepak; Karlgaard, Christopher D.; Kuhl, Christopher A.; Santos, Jose A.; Wright, Michael J.

2014-01-01

The Mars Science Laboratory (MSL) entry vehicle (EV) successfully entered the Mars atmosphere and landed the Curiosity rover safely on the surface of the planet in Gale crater on August 6, 2012. MSL carried the MSL Entry, Descent, and Landing (EDL) Instrumentation (MEDLI). MEDLI delivered the first in-depth understanding of the Mars entry environments and the response of the entry vehicle to those environments. MEDLI was comprised of three major subsystems: the Mars Entry Atmospheric Data System (MEADS), the MEDLI Integrated Sensor Plugs (MISP), and the Sensor Support Electronics (SSE). Ultimately, the entire MEDLI sensor suite consisting of both MEADS and MISP provided measurements that were used for trajectory reconstruction and engineering validation of aerodynamic, atmospheric, and thermal protection system (TPS) models in addition to Earth-based systems testing procedures. This report contains in-depth hardware descriptions, performance evaluation, and data information of the three MEDLI subsystems.

Factors Associated with Overweight and Obesity among Children of Mexican Descent: Results of a Binational Study

Science.gov (United States)

Rosas, Lisa G.; Guendelman, Sylvia; Harley, Kim; Fernald, Lia C. H.; Neufeld, Lynnette; Mejia, Fabiola

2010-01-01

The prevalence of childhood obesity is high among young children of Mexican origin in the United States, however, the determinants are poorly understood. We conducted a binational study with a sample from California (CA) and Mexico (MX), to identify and compare the most important factors associated with overweight and obesity among children of Mexican descent. Significantly more children were classified as overweight or obese in CA compared to MX (53.3 vs. 14.9%, P obese mother was significantly associated with being overweight or obese. In MX, male gender, high socioeconomic status and very low food insecurity were associated with being overweight or obese. These data offer hypotheses for how migration may influence the high prevalence of overweight among the Mexican children in California. PMID:20217234

On the Strong Convergence of a Sufficient Descent Polak-Ribière-Polyak Conjugate Gradient Method

Directory of Open Access Journals (Sweden)

Min Sun

2014-01-01

Full Text Available Recently, Zhang et al. proposed a sufficient descent Polak-Ribière-Polyak (SDPRP conjugate gradient method for large-scale unconstrained optimization problems and proved its global convergence in the sense that lim infk→∞∥∇f(xk∥=0 when an Armijo-type line search is used. In this paper, motivated by the line searches proposed by Shi et al. and Zhang et al., we propose two new Armijo-type line searches and show that the SDPRP method has strong convergence in the sense that limk→∞∥∇f(xk∥=0 under the two new line searches. Numerical results are reported to show the efficiency of the SDPRP with the new Armijo-type line searches in practical computation.

Familial LCAT deficiency. Report of two patients from a Canadian family of Italian and Swedish descent.

Science.gov (United States)

Frohlich, J; Godolphin, W J; Reeve, C E; Evelyn, K A

1978-01-01

A 16-year-old male (S.F.) and his 21-year-old sister (D.H.) from a large family of Italian and Swedish descent had virtually identical lipoprotein pattern and complete absence of LCAT activity. Both had typical corneal opacities and mild anemia with target cells. S.F., but not D.H., presented with proteinuria, which has increased over three years of follow-up. His kidney biopsy revealed lipid deposits in the glomerular basement membrane. Ten relatives in 4 generations had normal LCAT activity and/or lipoprotein pattern. The patients and their relatives had haptoglobin type 2. Factors that might influence the different clinical presentation in our patients (previous renal disease, diet, abnormal lipoproteins), prognosis, and treatment (diet, enzyme replacement, cholestyramine) are discussed.

Multidisciplinary Tool for Systems Analysis of Planetary Entry, Descent, and Landing

Science.gov (United States)

Samareh, Jamshid A.

2011-01-01

Systems analysis of a planetary entry (SAPE), descent, and landing (EDL) is a multidisciplinary activity in nature. SAPE improves the performance of the systems analysis team by automating and streamlining the process, and this improvement can reduce the errors that stem from manual data transfer among discipline experts. SAPE is a multidisciplinary tool for systems analysis of planetary EDL for Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, and Titan. It performs EDL systems analysis for any planet, operates cross-platform (i.e., Windows, Mac, and Linux operating systems), uses existing software components and open-source software to avoid software licensing issues, performs low-fidelity systems analysis in one hour on a computer that is comparable to an average laptop, and keeps discipline experts in the analysis loop. SAPE uses Python, a platform-independent, open-source language, for integration and for the user interface. Development has relied heavily on the object-oriented programming capabilities that are available in Python. Modules are provided to interface with commercial and government off-the-shelf software components (e.g., thermal protection systems and finite-element analysis). SAPE currently includes the following analysis modules: geometry, trajectory, aerodynamics, aerothermal, thermal protection system, and interface for structural sizing.

Exploring the 3D Surfaces with Modified Method of Steepest Descent

Directory of Open Access Journals (Sweden)

Wioletta GRZENDA

2012-06-01

Full Text Available Aim: To prove expediency of the steepest descent method to divide a given cloud of (Y, X1, X2 points into the spatial clusters with purpose to estimate a simple regression model Y = f(Z|X1,X2 at each cluster. Material and Method: The exemplary data sets {Y, X1, X2} were drawn randomly from assumed 3D surface: Y = f(X1,X2, and then a random noise was added to variable Y. A polynomial model Y = f(X1,X2 and a set of models Y = f(Z|X1,X2 were estimated separately, both under Akaike information criterion (AIC, and then compared with respect to their determination coefficients R-square, and the residuals’ distributions. Results: In the artificial data set studied, the both compared methods after several iterations can provide regression models of the quite similar quality. Conclusions: Because the proposed novel method seems to be more robust to outliers, and easier to graphical presentations and to intuitive understanding than the conventional way of building a regression model, the proposed novel method can be recommended to use by non-statisticians, especially in situation when, besides usual moderate noise, the sporadic but influential measurement errors can occur.

An online supervised learning method based on gradient descent for spiking neurons.

Science.gov (United States)

Xu, Yan; Yang, Jing; Zhong, Shuiming

2017-09-01

The purpose of supervised learning with temporal encoding for spiking neurons is to make the neurons emit a specific spike train encoded by precise firing times of spikes. The gradient-descent-based (GDB) learning methods are widely used and verified in the current research. Although the existing GDB multi-spike learning (or spike sequence learning) methods have good performance, they work in an offline manner and still have some limitations. This paper proposes an online GDB spike sequence learning method for spiking neurons that is based on the online adjustment mechanism of real biological neuron synapses. The method constructs error function and calculates the adjustment of synaptic weights as soon as the neurons emit a spike during their running process. We analyze and synthesize desired and actual output spikes to select appropriate input spikes in the calculation of weight adjustment in this paper. The experimental results show that our method obviously improves learning performance compared with the offline learning manner and has certain advantage on learning accuracy compared with other learning methods. Stronger learning ability determines that the method has large pattern storage capacity. Copyright © 2017 Elsevier Ltd. All rights reserved.

Parente2: a fast and accurate method for detecting identity by descent

KAUST Repository

Rodriguez, Jesse M.; Bercovici, Sivan; Huang, Lin; Frostig, Roy; Batzoglou, Serafim

2014-01-01

Identity-by-descent (IBD) inference is the problem of establishing a genetic connection between two individuals through a genomic segment that is inherited by both individuals from a recent common ancestor. IBD inference is an important preceding step in a variety of population genomic studies, ranging from demographic studies to linking genomic variation with phenotype and disease. The problem of accurate IBD detection has become increasingly challenging with the availability of large collections of human genotypes and genomes: Given a cohort's size, a quadratic number of pairwise genome comparisons must be performed. Therefore, computation time and the false discovery rate can also scale quadratically. To enable accurate and efficient large-scale IBD detection, we present Parente2, a novel method for detecting IBD segments. Parente2 is based on an embedded log-likelihood ratio and uses a model that accounts for linkage disequilibrium by explicitly modeling haplotype frequencies. Parente2 operates directly on genotype data without the need to phase data prior to IBD inference. We evaluate Parente2's performance through extensive simulations using real data, and we show that it provides substantially higher accuracy compared to previous state-of-the-art methods while maintaining high computational efficiency.

Stochastic parallel gradient descent based adaptive optics used for a high contrast imaging coronagraph

International Nuclear Information System (INIS)

Dong Bing; Ren Deqing; Zhang Xi

2011-01-01

An adaptive optics (AO) system based on a stochastic parallel gradient descent (SPGD) algorithm is proposed to reduce the speckle noises in the optical system of a stellar coronagraph in order to further improve the contrast. The principle of the SPGD algorithm is described briefly and a metric suitable for point source imaging optimization is given. The feasibility and good performance of the SPGD algorithm is demonstrated by an experimental system featured with a 140-actuator deformable mirror and a Hartmann-Shark wavefront sensor. Then the SPGD based AO is applied to a liquid crystal array (LCA) based coronagraph to improve the contrast. The LCA can modulate the incoming light to generate a pupil apodization mask of any pattern. A circular stepped pattern is used in our preliminary experiment and the image contrast shows improvement from 10 -3 to 10 -4.5 at an angular distance of 2λ/D after being corrected by SPGD based AO.

The Unparalleled Systems Engineering of MSL's Backup Entry, Descent, and Landing System: Second Chance

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Roumeliotis, Chris; Grinblat, Jonathan; Reeves, Glenn

2013-01-01

Second Chance (SECC) was a bare bones version of Mars Science Laboratory's (MSL) Entry Descent & Landing (EDL) flight software that ran on Curiosity's backup computer, which could have taken over swiftly in the event of a reset of Curiosity's prime computer, in order to land her safely on Mars. Without SECC, a reset of Curiosity's prime computer would have lead to catastrophic mission failure. Even though a reset of the prime computer never occurred, SECC had the important responsibility as EDL's guardian angel, and this responsibility would not have seen such success without unparalleled systems engineering. This paper will focus on the systems engineering behind SECC: Covering a brief overview of SECC's design, the intense schedule to use SECC as a backup system, the verification and validation of the system's "Do No Harm" mandate, the system's overall functional performance, and finally, its use on the fateful day of August 5th, 2012.

Guidance and Control Algorithms for the Mars Entry, Descent and Landing Systems Analysis

Science.gov (United States)

Davis, Jody L.; CwyerCianciolo, Alicia M.; Powell, Richard W.; Shidner, Jeremy D.; Garcia-Llama, Eduardo

2010-01-01

The purpose of the Mars Entry, Descent and Landing Systems Analysis (EDL-SA) study was to identify feasible technologies that will enable human exploration of Mars, specifically to deliver large payloads to the Martian surface. This paper focuses on the methods used to guide and control two of the contending technologies, a mid- lift-to-drag (L/D) rigid aeroshell and a hypersonic inflatable aerodynamic decelerator (HIAD), through the entry portion of the trajectory. The Program to Optimize Simulated Trajectories II (POST2) is used to simulate and analyze the trajectories of the contending technologies and guidance and control algorithms. Three guidance algorithms are discussed in this paper: EDL theoretical guidance, Numerical Predictor-Corrector (NPC) guidance and Analytical Predictor-Corrector (APC) guidance. EDL-SA also considered two forms of control: bank angle control, similar to that used by Apollo and the Space Shuttle, and a center-of-gravity (CG) offset control. This paper presents the performance comparison of these guidance algorithms and summarizes the results as they impact the technology recommendations for future study.

Degradation of Emerald green in oil paint and its contribution to the rapid change in colour of the Descente des vaches (1834-1835) painted by Theodore Rousseau

NARCIS (Netherlands)

Keune, K.; Boon, J.J.; Boitelle, R.; Shimadzu, Y.

2013-01-01

Descente des vaches (1836) by Theodore Rousseau in the Mesdag Collection in The Hague is barely readable and its paint layers are in poor condition. The surface of the painting is strongly deformed and cracked, the whole painting has darkened and especially the greens have lost all or most of their

Two-way regularization for MEG source reconstruction via multilevel coordinate descent

KAUST Repository

Siva Tian, Tian

2013-12-01

Magnetoencephalography (MEG) source reconstruction refers to the inverse problem of recovering the neural activity from the MEG time course measurements. A spatiotemporal two-way regularization (TWR) method was recently proposed by Tian et al. to solve this inverse problem and was shown to outperform several one-way regularization methods and spatiotemporal methods. This TWR method is a two-stage procedure that first obtains a raw estimate of the source signals and then refines the raw estimate to ensure spatial focality and temporal smoothness using spatiotemporal regularized matrix decomposition. Although proven to be effective, the performance of two-stage TWR depends on the quality of the raw estimate. In this paper we directly solve the MEG source reconstruction problem using a multivariate penalized regression where the number of variables is much larger than the number of cases. A special feature of this regression is that the regression coefficient matrix has a spatiotemporal two-way structure that naturally invites a two-way penalty. Making use of this structure, we develop a computationally efficient multilevel coordinate descent algorithm to implement the method. This new one-stage TWR method has shown its superiority to the two-stage TWR method in three simulation studies with different levels of complexity and a real-world MEG data analysis. © 2013 Wiley Periodicals, Inc., A Wiley Company.

Shape tracking with occlusions via coarse-to-fine region-based sobolev descent

KAUST Repository

Yang, Yanchao

2015-05-01

We present a method to track the shape of an object from video. The method uses a joint shape and appearance model of the object, which is propagated to match shape and radiance in subsequent frames, determining object shape. Self-occlusions and dis-occlusions of the object from camera and object motion pose difficulties to joint shape and appearance models in tracking. They are unable to adapt to new shape and appearance information, leading to inaccurate shape detection. In this work, we model self-occlusions and dis-occlusions in a joint shape and appearance tracking framework. Self-occlusions and the warp to propagate the model are coupled, thus we formulate a joint optimization problem. We derive a coarse-to-fine optimization method, advantageous in tracking, that initially perturbs the model by coarse perturbations before transitioning to finer-scale perturbations seamlessly. This coarse-to-fine behavior is automatically induced by gradient descent on a novel infinite-dimensional Riemannian manifold that we introduce. The manifold consists of planar parameterized regions, and the metric that we introduce is a novel Sobolev metric. Experiments on video exhibiting occlusions/dis-occlusions, complex radiance and background show that occlusion/dis-occlusion modeling leads to superior shape accuracy. © 2014 IEEE.

Parente2: a fast and accurate method for detecting identity by descent

KAUST Repository

Rodriguez, Jesse M.

2014-10-01

Identity-by-descent (IBD) inference is the problem of establishing a genetic connection between two individuals through a genomic segment that is inherited by both individuals from a recent common ancestor. IBD inference is an important preceding step in a variety of population genomic studies, ranging from demographic studies to linking genomic variation with phenotype and disease. The problem of accurate IBD detection has become increasingly challenging with the availability of large collections of human genotypes and genomes: Given a cohort\\'s size, a quadratic number of pairwise genome comparisons must be performed. Therefore, computation time and the false discovery rate can also scale quadratically. To enable accurate and efficient large-scale IBD detection, we present Parente2, a novel method for detecting IBD segments. Parente2 is based on an embedded log-likelihood ratio and uses a model that accounts for linkage disequilibrium by explicitly modeling haplotype frequencies. Parente2 operates directly on genotype data without the need to phase data prior to IBD inference. We evaluate Parente2\\'s performance through extensive simulations using real data, and we show that it provides substantially higher accuracy compared to previous state-of-the-art methods while maintaining high computational efficiency.

Manifold regularized discriminative nonnegative matrix factorization with fast gradient descent.

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Guan, Naiyang; Tao, Dacheng; Luo, Zhigang; Yuan, Bo

2011-07-01

Nonnegative matrix factorization (NMF) has become a popular data-representation method and has been widely used in image processing and pattern-recognition problems. This is because the learned bases can be interpreted as a natural parts-based representation of data and this interpretation is consistent with the psychological intuition of combining parts to form a whole. For practical classification tasks, however, NMF ignores both the local geometry of data and the discriminative information of different classes. In addition, existing research results show that the learned basis is unnecessarily parts-based because there is neither explicit nor implicit constraint to ensure the representation parts-based. In this paper, we introduce the manifold regularization and the margin maximization to NMF and obtain the manifold regularized discriminative NMF (MD-NMF) to overcome the aforementioned problems. The multiplicative update rule (MUR) can be applied to optimizing MD-NMF, but it converges slowly. In this paper, we propose a fast gradient descent (FGD) to optimize MD-NMF. FGD contains a Newton method that searches the optimal step length, and thus, FGD converges much faster than MUR. In addition, FGD includes MUR as a special case and can be applied to optimizing NMF and its variants. For a problem with 165 samples in R(1600), FGD converges in 28 s, while MUR requires 282 s. We also apply FGD in a variant of MD-NMF and experimental results confirm its efficiency. Experimental results on several face image datasets suggest the effectiveness of MD-NMF.

Mars 2020 Entry, Descent and Landing Instrumentation (MEDLI2)

Science.gov (United States)

Bose, Deepak; Wright, Henry; White, Todd; Schoenenberger, Mark; Santos, Jose; Karlgaard, Chris; Kuhl, Chris; Oishi, TOmo; Trombetta, Dominic

2016-01-01

This paper will introduce Mars Entry Descent and Landing Instrumentation (MEDLI2) on NASA's Mars2020 mission. Mars2020 is a flagship NASA mission with science and technology objectives to help answer questions about possibility of life on Mars as well as to demonstrate technologies for future human expedition. Mars2020 is scheduled for launch in 2020. MEDLI2 is a suite of instruments embedded in the heatshield and backshell thermal protection systems of Mars2020 entry vehicle. The objectives of MEDLI2 are to gather critical aerodynamics, aerothermodynamics and TPS performance data during EDL phase of the mission. MEDLI2 builds up the success of MEDLI flight instrumentation on Mars Science Laboratory mission in 2012. MEDLI instrumentation suite measured surface pressure and TPS temperature on the heatshield during MSL entry into Mars. MEDLI data has since been used for unprecedented reconstruction of aerodynamic drag, vehicle attitude, in-situ atmospheric density, aerothermal heating, transition to turbulence, in-depth TPS performance and TPS ablation. [1,2] In addition to validating predictive models, MEDLI data has highlighted extra margin available in the MSL forebody TPS, which can potentially be used to reduce vehicle parasitic mass. MEDLI2 expands the scope of instrumentation by focusing on quantities of interest not addressed in MEDLI suite. The type the sensors are expanded and their layout on the TPS modified to meet these new objectives. The paper will provide key motivation and governing requirements that drive the choice and the implementation of the new sensor suite. The implementation considerations of sensor selection, qualification, and demonstration of minimal risk to the host mission will be described. The additional challenges associated with mechanical accommodation, electrical impact, data storage and retrieval for MEDLI2 system, which extends sensors to backshell will also be described.

Direct-to-Earth Communications with Mars Science Laboratory During Entry, Descent, and Landing

Science.gov (United States)

Soriano, Melissa; Finley, Susan; Fort, David; Schratz, Brian; Ilott, Peter; Mukai, Ryan; Estabrook, Polly; Oudrhiri, Kamal; Kahan, Daniel; Satorius, Edgar

2013-01-01

Mars Science Laboratory (MSL) undergoes extreme heating and acceleration during Entry, Descent, and Landing (EDL) on Mars. Unknown dynamics lead to large Doppler shifts, making communication challenging. During EDL, a special form of Multiple Frequency Shift Keying (MFSK) communication is used for Direct-To-Earth (DTE) communication. The X-band signal is received by the Deep Space Network (DSN) at the Canberra Deep Space Communication complex, then down-converted, digitized, and recorded by open-loop Radio Science Receivers (RSR), and decoded in real-time by the EDL Data Analysis (EDA) System. The EDA uses lock states with configurable Fast Fourier Transforms to acquire and track the signal. RSR configuration and channel allocation is shown. Testing prior to EDL is discussed including software simulations, test bed runs with MSL flight hardware, and the in-flight end-to-end test. EDA configuration parameters and signal dynamics during pre-entry, entry, and parachute deployment are analyzed. RSR and EDA performance during MSL EDL is evaluated, including performance using a single 70-meter DSN antenna and an array of two 34-meter DSN antennas as a back up to the 70-meter antenna.

En Route Descent Advisor Multi-Sector Planning Using Active and Provisional Controller Plans

Science.gov (United States)

Vivona, Robert; Green, Steven

2003-01-01

As decision support tools are developed to support controllers in complex air traffic control environments, new approaches to maintaining situation awareness and managing traffic planning must be developed to handle the ever-increasing amounts of alerting and advisory data. Within high-density metering and other environments where flight path changes are the rule, not the exception, and where interactions between these changes are required, current trial planning approaches are limited by potential increases in workload. The Enroute Descent Advisor (EDA) is a set of decision support tool capabilities for managing high-density en route traffic subject to metering restrictions. The EDA system s novel approach builds aircraft plans from combinations of user intent data and builds controller plans from combinations of aircraft plans to effectively maintain situation awareness during traffic planning. By maintaining both active (current) and provisional (proposed) controller plans, EDA supports controllers in coordinated traffic planning both within and between sectors. Ultimately, EDA s multi-sector planning approach will facilitate a transition from current sector-oriented operations to a new trajectory-oriented paradigm, enabling new levels of efficiency and collaboration in air traffic control.

Optimization of axial enrichment distribution for BWR fuels using scoping libraries and block coordinate descent method

Energy Technology Data Exchange (ETDEWEB)

Tung, Wu-Hsiung, E-mail: wstong@iner.gov.tw; Lee, Tien-Tso; Kuo, Weng-Sheng; Yaur, Shung-Jung

2017-03-15

Highlights: • An optimization method for axial enrichment distribution in a BWR fuel was developed. • Block coordinate descent method is employed to search for optimal solution. • Scoping libraries are used to reduce computational effort. • Optimization search space consists of enrichment difference parameters. • Capability of the method to find optimal solution is demonstrated. - Abstract: An optimization method has been developed to search for the optimal axial enrichment distribution in a fuel assembly for a boiling water reactor core. The optimization method features: (1) employing the block coordinate descent method to find the optimal solution in the space of enrichment difference parameters, (2) using scoping libraries to reduce the amount of CASMO-4 calculation, and (3) integrating a core critical constraint into the objective function that is used to quantify the quality of an axial enrichment design. The objective function consists of the weighted sum of core parameters such as shutdown margin and critical power ratio. The core parameters are evaluated by using SIMULATE-3, and the cross section data required for the SIMULATE-3 calculation are generated by using CASMO-4 and scoping libraries. The application of the method to a 4-segment fuel design (with the highest allowable segment enrichment relaxed to 5%) demonstrated that the method can obtain an axial enrichment design with improved thermal limit ratios and objective function value while satisfying the core design constraints and core critical requirement through the use of an objective function. The use of scoping libraries effectively reduced the number of CASMO-4 calculation, from 85 to 24, in the 4-segment optimization case. An exhausted search was performed to examine the capability of the method in finding the optimal solution for a 4-segment fuel design. The results show that the method found a solution very close to the optimum obtained by the exhausted search. The number of

Social Identity in New Mexicans of Spanish-Speaking Descent Highlights Limitations of Using Standardized Ethnic Terminology in Research.

Science.gov (United States)

Hunley, Keith; Edgar, Heather; Healy, Meghan; Mosley, Carmen; Cabana, Graciela S; West, Frankie

2017-07-01

In this study, we evaluated the extent to which regional history has shaped the social identity nomenclature in New Mexicans of Spanish-speaking descent (NMSD). We asked 507 NMSD to list the social-identity terms they used to describe themselves and their parents, and we examined the correspondence between these choices and family ties to the region, birthplace, and continental ancestry. NMSD frequently identified using the regional terms "Nuevomexicano/a" (15%) and "Spanish" (12%). These individuals reported family ties to the region that predate New Mexican statehood. They and their parents were frequently born in New Mexico, frequently chose the other of the two terms as a secondary descriptor, and frequently ascribed one of the two terms to their parents. About 10% of NMSD identified as "Mexican American" and "Mexican." About 25% of these individuals, and more than half of their parents, were born in Mexico. They also frequently chose the other of the two terms as a secondary descriptor and frequently ascribed one of the two terms to their parents. Compared to NMSD who identified as "Mexican" and "Mexican American," individuals who identified as "Nuevomexicano/a" and "Spanish" had higher European ancestry and lower Native American and African ancestry. Our results also suggest that the term "Hispanic," frequently chosen as both a primary and secondary social identity term by NMSD, may, as it continues to rise in prominence, mask more deeply rooted and potential socially relevant aspects of social identity in New Mexico. More broadly, these results indicate that regional history influences social identity nomenclatures in ways that are potentially incompatible with US Office of Management and Budget standards. This incompatibility may adversely affect the ability of researchers in the social sciences to assess the causes of social inequality and health disparities in individuals of Spanish-speaking descent in different regions of the United States. We argue that

Assessment of environments for Mars Science Laboratory entry, descent, and surface operations

Science.gov (United States)

Vasavada, Ashwin R.; Chen, Allen; Barnes, Jeffrey R.; Burkhart, P. Daniel; Cantor, Bruce A.; Dwyer-Cianciolo, Alicia M.; Fergason, Robini L.; Hinson, David P.; Justh, Hilary L.; Kass, David M.; Lewis, Stephen R.; Mischna, Michael A.; Murphy, James R.; Rafkin, Scot C.R.; Tyler, Daniel; Withers, Paul G.

2012-01-01

The Mars Science Laboratory mission aims to land a car-sized rover on Mars' surface and operate it for at least one Mars year in order to assess whether its field area was ever capable of supporting microbial life. Here we describe the approach used to identify, characterize, and assess environmental risks to the landing and rover surface operations. Novel entry, descent, and landing approaches will be used to accurately deliver the 900-kg rover, including the ability to sense and "fly out" deviations from a best-estimate atmospheric state. A joint engineering and science team developed methods to estimate the range of potential atmospheric states at the time of arrival and to quantitatively assess the spacecraft's performance and risk given its particular sensitivities to atmospheric conditions. Numerical models are used to calculate the atmospheric parameters, with observations used to define model cases, tune model parameters, and validate results. This joint program has resulted in a spacecraft capable of accessing, with minimal risk, the four finalist sites chosen for their scientific merit. The capability to operate the landed rover over the latitude range of candidate landing sites, and for all seasons, was verified against an analysis of surface environmental conditions described here. These results, from orbital and model data sets, also drive engineering simulations of the rover's thermal state that are used to plan surface operations.

The detailed measurement of foot clearance by young adults during stair descent.

Science.gov (United States)

Telonio, A; Blanchet, S; Maganaris, C N; Baltzopoulos, V; McFadyen, B J

2013-04-26

Foot clearance is an important variable for understanding safe stair negotiation, but few studies have provided detailed measures of it. This paper presents a new method to calculate minimal shoe clearance during stair descent and compares it to previous literature. Seventeen healthy young subjects descended a five step staircase with step treads of 300 mm and step heights of 188 mm. Kinematic data were collected with an Optotrak system (model 3020) and three non-colinear infrared markers on the feet. Ninety points were digitized on the foot sole prior to data collection using a 6 marker probe and related to the triad of markers on the foot. The foot sole was reconstructed using the Matlab (version 7.0) "meshgrid" function and minimal distance to each step edge was calculated for the heel, toe and foot sole. Results showed significant differences in minimum clearance between sole, heel and toe, with the shoe sole being the closest and the toe the furthest. While the hind foot sole was closest for 69% of the time, the actual minimum clearance point on the sole did vary across subjects and staircase steps. This new method, and the findings on healthy young subjects, can be applied to future studies of other populations and staircase dimensions. Copyright © 2013 Elsevier Ltd. All rights reserved.

A New Modified Three-Term Conjugate Gradient Method with Sufficient Descent Property and Its Global Convergence

Directory of Open Access Journals (Sweden)

Bakhtawar Baluch

2017-01-01

Full Text Available A new modified three-term conjugate gradient (CG method is shown for solving the large scale optimization problems. The idea relates to the famous Polak-Ribière-Polyak (PRP formula. As the numerator of PRP plays a vital role in numerical result and not having the jamming issue, PRP method is not globally convergent. So, for the new three-term CG method, the idea is to use the PRP numerator and combine it with any good CG formula’s denominator that performs well. The new modification of three-term CG method possesses the sufficient descent condition independent of any line search. The novelty is that by using the Wolfe Powell line search the new modification possesses global convergence properties with convex and nonconvex functions. Numerical computation with the Wolfe Powell line search by using the standard test function of optimization shows the efficiency and robustness of the new modification.

A Rigid Mid-Lift-to-Drag Ratio Approach to Human Mars Entry, Descent, and Landing

Science.gov (United States)

Cerimele, Christopher J.; Robertson, Edward A.; Sostaric, Ronald R.; Campbell, Charles H.; Robinson, Phil; Matz, Daniel A.; Johnson, Breanna J.; Stachowiak, Susan J.; Garcia, Joseph A.; Bowles, Jeffrey V.;

Critical Spacecraft-to-Earth Communications for Mars Exploration Rover (MER) entry, descent and landing

Science.gov (United States)

Hurd, William J.; Estabrook, Polly; Racho, Caroline S.; Satorius, Edgar H.

2002-01-01

For planetary lander missions, the most challenging phase of the spacecraft to ground communications is during the entry, descent, and landing (EDL). As each 2003 Mars Exploration Rover (MER) enters the Martian atmosphere, it slows dramatically. The extreme acceleration and jerk cause extreme Doppler dynamics on the X-band signal received on Earth. When the vehicle slows sufficiently, the parachute is deployed, causing almost a step in deceleration. After parachute deployment, the lander is lowered beneath the parachute on a bridle. The swinging motion of the lander imparts high Doppler dynamics on the signal and causes the received signal strength to vary widely, due to changing antenna pointing angles. All this time, the vehicle transmits important health and status information that is especially critical if the landing is not successful. Even using the largest Deep Space Network antennas, the weak signal and high dynamics render it impossible to conduct reliable phase coherent communications. Therefore, a specialized form of frequency-shift-keying will be used. This paper describes the EDL scenario, the signal conditions, the methods used to detect and frequency-track the carrier and to detect the data modulation, and the resulting performance estimates.

Timing of left heart base descent in dogs with dilated cardiomyopathy and normal dogs.

Science.gov (United States)

Simpson, Kerry E; Devine, Bryan C; Woolley, Richard; Corcoran, Brendan M; French, Anne T

2008-01-01

The identification and assessment of myocardial failure in canine idiopathic dilated cardiomyopathy (DCM) is achieved using a variety of two-dimensional and Doppler echocardiographic techniques. More recently, the availability of tissue Doppler imaging (TDI) has raised the potential for development of new ways of more accurately identifying a disease phenotype. Nevertheless, TDI has not been universally adapted to veterinary clinical cardiology primarily because of the lack of information on its utility in diagnosis. We assessed the application of timing of left heart base descent using TDI in the identification of differences between DCM and normal dogs. The times from the onset of the QRS complex on a simultaneously recorded electrocardiograph to the onset (Q--S'), peak (Q--peak S'), and end (Q--end S') of the systolic velocity peak were measured in the interventricular septum (IVS) and the left ventricular free wall. The duration of S' was also calculated. The Q--S' (FW), Q--end S' (FW), and duration S' (FW) were correlated with ejection fraction in the diseased group (P canine DCM and identifies new TDI parameters that can be added to the range of Doppler and echocardiographic parameters used for detecting myocardial failure in the dog.

Haplotype assembly in polyploid genomes and identical by descent shared tracts.

Science.gov (United States)

Aguiar, Derek; Istrail, Sorin

2013-07-01

Genome-wide haplotype reconstruction from sequence data, or haplotype assembly, is at the center of major challenges in molecular biology and life sciences. For complex eukaryotic organisms like humans, the genome is vast and the population samples are growing so rapidly that algorithms processing high-throughput sequencing data must scale favorably in terms of both accuracy and computational efficiency. Furthermore, current models and methodologies for haplotype assembly (i) do not consider individuals sharing haplotypes jointly, which reduces the size and accuracy of assembled haplotypes, and (ii) are unable to model genomes having more than two sets of homologous chromosomes (polyploidy). Polyploid organisms are increasingly becoming the target of many research groups interested in the genomics of disease, phylogenetics, botany and evolution but there is an absence of theory and methods for polyploid haplotype reconstruction. In this work, we present a number of results, extensions and generalizations of compass graphs and our HapCompass framework. We prove the theoretical complexity of two haplotype assembly optimizations, thereby motivating the use of heuristics. Furthermore, we present graph theory-based algorithms for the problem of haplotype assembly using our previously developed HapCompass framework for (i) novel implementations of haplotype assembly optimizations (minimum error correction), (ii) assembly of a pair of individuals sharing a haplotype tract identical by descent and (iii) assembly of polyploid genomes. We evaluate our methods on 1000 Genomes Project, Pacific Biosciences and simulated sequence data. HapCompass is available for download at http://www.brown.edu/Research/Istrail_Lab/. Supplementary data are available at Bioinformatics online.

Ethnic, racial and cultural identity and perceived benefits and barriers related to genetic testing for breast cancer among at-risk women of African descent in New York City.

Science.gov (United States)

Sussner, K M; Edwards, T A; Thompson, H S; Jandorf, L; Kwate, N O; Forman, A; Brown, K; Kapil-Pair, N; Bovbjerg, D H; Schwartz, M D; Valdimarsdottir, H B

2011-01-01

Due to disparities in the use of genetic services, there has been growing interest in examining beliefs and attitudes related to genetic testing for breast and/or ovarian cancer risk among women of African descent. However, to date, few studies have addressed critical cultural variations among this minority group and their influence on such beliefs and attitudes. We assessed ethnic, racial and cultural identity and examined their relationships with perceived benefits and barriers related to genetic testing for cancer risk in a sample of 160 women of African descent (49% self-identified African American, 39% Black-West Indian/Caribbean, 12% Black-Other) who met genetic risk criteria and were participating in a larger longitudinal study including the opportunity for free genetic counseling and testing in New York City. All participants completed the following previously validated measures: (a) the multi-group ethnic identity measure (including ethnic search and affirmation subscales) and other-group orientation for ethnic identity, (b) centrality to assess racial identity, and (c) Africentrism to measure cultural identity. Perceived benefits and barriers related to genetic testing included: (1) pros/advantages (including family-related pros), (2) cons/disadvantages (including family-related cons, stigma and confidentiality concerns), and (3) concerns about abuses of genetic testing. In multivariate analyses, several ethnic identity elements showed significant, largely positive relationships to perceived benefits about genetic testing for breast and/or ovarian cancer risk, the exception being ethnic search, which was positively associated with cons/disadvantages, in general, and family-related cons/disadvantages. Racial identity (centrality) showed a significant association with confidentiality concerns. Cultural identity (Africentrism) was not related to perceived benefits and/or barriers. Ethnic and racial identity may influence perceived benefits and barriers

Moving away from a cultural deficit to a holistic perspective: Traditional gender role values, academic attitudes, and educational goals for Mexican descent adolescents.

Science.gov (United States)

Piña-Watson, Brandy; Lorenzo-Blanco, Elma I; Dornhecker, Marianela; Martinez, Ashley J; Nagoshi, Julie L

2016-04-01

Latina/o youth lag behind Asian American and non-Latina/o White youth in many academic areas. Previous research has taken a deficit approach to understand the factors that affect academic outcomes for Latina/o youth often neglecting to highlight both the potential positive and negative contributions of gender role values. The present study took a holistic perspective to understand the affect of traditional Latina/o gender role values (i.e., marianismo, machismo, and caballerismo) on the academic attitudes and educational goals of Mexican descent youth. Structural equation models were tested to examine the associations of "positive" and "negative" gender role values on educational goals using 524 Mexican descent adolescents from a mid-sized city in southern Texas. We hypothesized that positive aspects of traditional Latina/o gender role values (i.e., "positive marianismo" and caballerismo) would be associated with more positive attitudes toward academics and higher educational goals. We further expected negative gender role values (i.e., "negative marianismo" and machismo) to have the opposite effect. Additionally, based on the theory of planned behavior and gender schema theory, academic attitudes were hypothesized to mediate the relation between gender role values and educational goals. An alternative model was tested in which educational goals mediated the relation between gender roles and academic attitudes. Results indicated that both models fit the data well, and recommendations are made for future longitudinal research aimed at disentangling the directionality of the relations in the model. Implications for research and practice are discussed. (c) 2016 APA, all rights reserved).

Acculturation, maternal cortisol and birth outcomes in women of Mexican descent

Science.gov (United States)

D’Anna, Kimberly L.; Hoffman, M. Camille; Zerbe, Gary O.; Coussons-Read, Mary; Ross, Randal G.; Laudenslager, Mark L.

2012-01-01

Objective This study investigated the effects of acculturation on cortisol, a biological correlate of maternal psychological distress, and perinatal infant outcomes, specifically gestational age at birth and birth weight. Methods Fifty-five pregnant women of Mexican descent were recruited from a community hospital and collected saliva samples at home over 3 days during pregnancy at 15–18 (early), 26–2 (mid), and 32+ (late) weeks gestation and once in the postpartum period (4–12 weeks). These values were used to determine the diurnal cortisol slope at each phase of pregnancy. Mothers also completed an acculturation survey and gave permission for a medical chart review to obtain neonate information. Results Multiple regression analyses determined that greater acculturation levels significantly predicted earlier infant gestational age at birth (R2=0.09, p=0.03). T-tests revealed that mothers of low birth weight infants weight (acculturation scores than mothers of infants with birth weight >2500g (t=−2.95, p=0.005). A blunted maternal cortisol slope during pregnancy was also correlated with low birth weight (r=−0.29, p=0.05), but not gestational age (r=−0.08, p=0.59). In addition, more acculturated women had a flatter diurnal cortisol slope late in pregnancy (R2=0.21, p=0.01). Finally diurnal maternal cortisol rhythms were identified as a potential mediator between increased acculturation and birth weight. Conclusions This study associated increased acculturation with perinatal outcomes in the US Mexican population. This relationship may be mediated by prenatal maternal diurnal cortisol, which can program the health of the fetus leading to several adverse perinatal outcomes. PMID:22366584

Phrenic Nerve Conduction Abnormalities Correlate with Diaphragmatic Descent in Chronic Obstructive Pulmonary Disease.

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El-Tantawi, Gihan A Younis; Imam, Mohamed H; Morsi, Tamer S

2015-01-01

Diaphragmatic weakness in chronic obstructive pulmonary disease (COPD) is ascribed to hyperinflation-induced diaphragm shortening as well as impairment in cellular and subcellular structures. Although phrenic neuropathy is known to cause diaphragmatic weakness, phrenic neuropathy is rarely considered in COPD. This work aimed at assessing phrenic nerve conduction in COPD and its relation to radiographic hyperinflation and pulmonary function. Forty COPD patients were evaluated. Radiographic parameters of lung hyperinflation were measured on postero-anterior and lateral chest x-ray films. Flow volume loop parameters were obtained from all patients. Motor conduction study of the phrenic nerves was performed and potentials were recorded over the xiphoid process and the ipsilateral 7th intercostal space. Twenty-seven healthy subjects were enrolled as controls. Parameters of phrenic nerve conduction differed significantly in patients compared to controls. Phrenic nerve abnormalities were detected in 17 patients (42.5%). Electrophysiological measures correlated with diaphragmatic angle of depression on lateral view films and with lung height on postero-anterior films. They did not correlate with the flow volume loop data or disease severity score. Phrenic nerve conduction abnormality is an appreciated finding in COPD. Nerve stretching associated with diaphragmatic descent can be a suggested mechanism for nerve lesion. The presence of phrenic neuropathy may be an additional contributing factor to diaphragmatic dysfunction in COPD patients.

Genetic variation in CFH predicts phenytoin-induced maculopapular exanthema in European-descent patients.

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McCormack, Mark; Gui, Hongsheng; Ingason, Andrés; Speed, Doug; Wright, Galen E B; Zhang, Eunice J; Secolin, Rodrigo; Yasuda, Clarissa; Kwok, Maxwell; Wolking, Stefan; Becker, Felicitas; Rau, Sarah; Avbersek, Andreja; Heggeli, Kristin; Leu, Costin; Depondt, Chantal; Sills, Graeme J; Marson, Anthony G; Auce, Pauls; Brodie, Martin J; Francis, Ben; Johnson, Michael R; Koeleman, Bobby P C; Striano, Pasquale; Coppola, Antonietta; Zara, Federico; Kunz, Wolfram S; Sander, Josemir W; Lerche, Holger; Klein, Karl Martin; Weckhuysen, Sarah; Krenn, Martin; Gudmundsson, Lárus J; Stefánsson, Kári; Krause, Roland; Shear, Neil; Ross, Colin J D; Delanty, Norman; Pirmohamed, Munir; Carleton, Bruce C; Cendes, Fernando; Lopes-Cendes, Iscia; Liao, Wei-Ping; O'Brien, Terence J; Sisodiya, Sanjay M; Cherny, Stacey; Kwan, Patrick; Baum, Larry; Cavalleri, Gianpiero L

2018-01-23

To characterize, among European and Han Chinese populations, the genetic predictors of maculopapular exanthema (MPE), a cutaneous adverse drug reaction common to antiepileptic drugs. We conducted a case-control genome-wide association study of autosomal genotypes, including Class I and II human leukocyte antigen (HLA) alleles, in 323 cases and 1,321 drug-tolerant controls from epilepsy cohorts of northern European and Han Chinese descent. Results from each cohort were meta-analyzed. We report an association between a rare variant in the complement factor H-related 4 ( CFHR4 ) gene and phenytoin-induced MPE in Europeans ( p = 4.5 × 10 -11 ; odds ratio [95% confidence interval] 7 [3.2-16]). This variant is in complete linkage disequilibrium with a missense variant (N1050Y) in the complement factor H ( CFH ) gene. In addition, our results reinforce the association between HLA-A*31:01 and carbamazepine hypersensitivity. We did not identify significant genetic associations with MPE among Han Chinese patients. The identification of genetic predictors of MPE in CFHR4 and CFH, members of the complement factor H-related protein family, suggest a new link between regulation of the complement system alternative pathway and phenytoin-induced hypersensitivity in European-ancestral patients. Copyright © 2017 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the American Academy of Neurology.

Simulations of Continuous Descent Operations with Arrival-management Automation and Mixed Flight-deck Interval Management Equipage

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Callantine, Todd J.; Kupfer, Michael; Martin, Lynne Hazel; Prevot, Thomas

2013-01-01

Air traffic management simulations conducted in the Airspace Operations Laboratory at NASA Ames Research Center have addressed the integration of trajectory-based arrival-management automation, controller tools, and Flight-Deck Interval Management avionics to enable Continuous Descent Operations (CDOs) during periods of sustained high traffic demand. The simulations are devoted to maturing the integrated system for field demonstration, and refining the controller tools, clearance phraseology, and procedures specified in the associated concept of operations. The results indicate a variety of factors impact the concept's safety and viability from a controller's perspective, including en-route preconditioning of arrival flows, useable clearance phraseology, and the characteristics of airspace, routes, and traffic-management methods in use at a particular site. Clear understanding of automation behavior and required shifts in roles and responsibilities is important for controller acceptance and realizing potential benefits. This paper discusses the simulations, drawing parallels with results from related European efforts. The most recent study found en-route controllers can effectively precondition arrival flows, which significantly improved route conformance during CDOs. Controllers found the tools acceptable, in line with previous studies.

Os fantasmas e a revolução: uma leitura de "Descente de médiums", de Nathalie Quintane

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Larissa Drigo Agostinho

2015-07-01

Full Text Available Pretendemos neste texto tratar da relação entre literatura, teoria e política na obra de Nathalie Quintane. O livro em questão, Descente de médiums, discute, a partir do espiritismo a relação entre literatura, pensamento e política, buscando criticar toda perspectiva centrada numa crença em nome de uma relação entre literatura e realidade reconfigurada. Trata-se de discutir, no interior da literatura, a relevância política desta ou pensá-la como uma decisão num cenário pós-morte do autor. Salientaremos não apenas as novidades teóricas desta escrita para a crítica literária, bem como as experiências narrativas que reconstroem uma nova literatura engajada.

Preconditioned steepest descent methods for some nonlinear elliptic equations involving p-Laplacian terms

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Feng, Wenqiang, E-mail: wfeng1@vols.utk.edu [Department of Mathematics, The University of Tennessee, Knoxville, TN 37996 (United States); Salgado, Abner J., E-mail: asalgad1@utk.edu [Department of Mathematics, The University of Tennessee, Knoxville, TN 37996 (United States); Wang, Cheng, E-mail: cwang1@umassd.edu [Department of Mathematics, The University of Massachusetts, North Dartmouth, MA 02747 (United States); Wise, Steven M., E-mail: swise1@utk.edu [Department of Mathematics, The University of Tennessee, Knoxville, TN 37996 (United States)

2017-04-01

We describe and analyze preconditioned steepest descent (PSD) solvers for fourth and sixth-order nonlinear elliptic equations that include p-Laplacian terms on periodic domains in 2 and 3 dimensions. The highest and lowest order terms of the equations are constant-coefficient, positive linear operators, which suggests a natural preconditioning strategy. Such nonlinear elliptic equations often arise from time discretization of parabolic equations that model various biological and physical phenomena, in particular, liquid crystals, thin film epitaxial growth and phase transformations. The analyses of the schemes involve the characterization of the strictly convex energies associated with the equations. We first give a general framework for PSD in Hilbert spaces. Based on certain reasonable assumptions of the linear pre-conditioner, a geometric convergence rate is shown for the nonlinear PSD iteration. We then apply the general theory to the fourth and sixth-order problems of interest, making use of Sobolev embedding and regularity results to confirm the appropriateness of our pre-conditioners for the regularized p-Lapacian problems. Our results include a sharper theoretical convergence result for p-Laplacian systems compared to what may be found in existing works. We demonstrate rigorously how to apply the theory in the finite dimensional setting using finite difference discretization methods. Numerical simulations for some important physical application problems – including thin film epitaxy with slope selection and the square phase field crystal model – are carried out to verify the efficiency of the scheme.

The Book of Life: The South African population register and the invention of racial descent, 1950-1980

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Keith Breckenridge

Full Text Available This article examines the project of racial classification under Apartheid through the operations of the population register. It follows, in particular, a shift in the determination of race from the criterion of'community acceptance' in the early 1950s to a purely administrative and bureaucratic matter of descent derived from the paperwork in the late 1960s. The study shows that the project Eben Dönges called the 'Book of Life' was at the heart of the planning and practice of the Apartheid state, but that it took two contrasting forms. The first, associated with the green identity cards issued during the 1950s and early 1960s, derived identities and races for six million people, with surprising success, on the basis of the returns to the 1951 census. The second, associated with the inconvenient 50-page Book of Life that was issued after 1970, was a pure case of unrestrained panopticism and a simple failure, failing even to re-register the original population captured by the green identity cards.

Depression and emotional reactivity: variation among Asian Americans of East Asian descent and European Americans.

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Chentsova-Dutton, Yulia E; Chu, Joyce P; Tsai, Jeanne L; Rottenberg, Jonathan; Gross, James J; Gotlib, Ian H

2007-11-01

Studies of Western samples (e.g., European Americans [EAs]) suggest that depressed individuals tend to show diminished emotional reactivity (J. G. Gehricke & A. J. Fridlund, 2002; G. E. Schwartz, P. L. Fair, P. Salt, M. R. Mandel, & G. L. Klerman, 1976a, 1976b). Do these findings generalize to individuals oriented to other cultures (e.g., East Asian cultures)? The authors compared the emotional reactions (i.e., reports of emotional experience, facial behavior, and physiological reactivity) of depressed and nondepressed EAs and Asian Americans of East Asian descent (AAs) to sad and amusing films. Their results were consistent with previous findings: Depressed EAs showed a pattern of diminished reactivity to the sad film (less crying, less intense reports of sadness) compared with nondepressed participants. In contrast, depressed AAs showed a pattern of heightened emotional reactivity (greater crying) compared with nondepressed participants. Across cultural groups, depressed and nondepressed participants did not differ in their reports of amusement or facial behavior during the amusing film. Physiological reactivity to the film clips did not differ between depressed and control participants for either cultural group. Thus, although depression may influence particular aspects of emotional reactivity across cultures (e.g., crying), the specific direction of this influence may depend on prevailing cultural norms regarding emotional expression. (c) 2007 APA

Ptychographic overlap constraint errors and the limits of their numerical recovery using conjugate gradient descent methods.

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Tripathi, Ashish; McNulty, Ian; Shpyrko, Oleg G

2014-01-27

Ptychographic coherent x-ray diffractive imaging is a form of scanning microscopy that does not require optics to image a sample. A series of scanned coherent diffraction patterns recorded from multiple overlapping illuminated regions on the sample are inverted numerically to retrieve its image. The technique recovers the phase lost by detecting the diffraction patterns by using experimentally known constraints, in this case the measured diffraction intensities and the assumed scan positions on the sample. The spatial resolution of the recovered image of the sample is limited by the angular extent over which the diffraction patterns are recorded and how well these constraints are known. Here, we explore how reconstruction quality degrades with uncertainties in the scan positions. We show experimentally that large errors in the assumed scan positions on the sample can be numerically determined and corrected using conjugate gradient descent methods. We also explore in simulations the limits, based on the signal to noise of the diffraction patterns and amount of overlap between adjacent scan positions, of just how large these errors can be and still be rendered tractable by this method.

Conflation of Short Identity-by-Descent Segments Bias Their Inferred Length Distribution

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Charleston W. K. Chiang

2016-05-01

Full Text Available Identity-by-descent (IBD is a fundamental concept in genetics with many applications. In a common definition, two haplotypes are said to share an IBD segment if that segment is inherited from a recent shared common ancestor without intervening recombination. Segments several cM long can be efficiently detected by a number of algorithms using high-density SNP array data from a population sample, and there are currently efforts to detect shorter segments from sequencing. Here, we study a problem of identifiability: because existing approaches detect IBD based on contiguous segments of identity-by-state, inferred long segments of IBD may arise from the conflation of smaller, nearby IBD segments. We quantified this effect using coalescent simulations, finding that significant proportions of inferred segments 1–2 cM long are results of conflations of two or more shorter segments, each at least 0.2 cM or longer, under demographic scenarios typical for modern humans for all programs tested. The impact of such conflation is much smaller for longer (> 2 cM segments. This biases the inferred IBD segment length distribution, and so can affect downstream inferences that depend on the assumption that each segment of IBD derives from a single common ancestor. As an example, we present and analyze an estimator of the de novo mutation rate using IBD segments, and demonstrate that unmodeled conflation leads to underestimates of the ages of the common ancestors on these segments, and hence a significant overestimate of the mutation rate. Understanding the conflation effect in detail will make its correction in future methods more tractable.

Aerodynamics of Reentry Vehicle Clipper at Descent Phase

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Semenov, Yu. P.; Reshetin, A. G.; Dyadkin, A. A.; Petrov, N. K.; Simakova, T. V.; Tokarev, V. A.

2005-02-01

From Gagarin spacecraft to reusable orbiter Buran, RSC Energia has traveled a long way in the search for the most optimal and, which is no less important, the most reliable spacecraft for manned space flight. During the forty years of space exploration, in cooperation with a broad base of subcontractors, a number of problems have been solved which assure a safe long stay in space. Vostok and Voskhod spacecraft were replaced with Soyuz supporting a crew of three. During missions to a space station, it provides crew rescue capability in case of a space station emergency at all times (the spacecraft life is 200 days).The latest modification of Soyuz spacecraft -Soyuz TMA -in contrast to its predecessors, allows to become a space flight participant to a person of virtually any anthropometric parameters with a mass of 50 to 95 kg capable of withstanding up to 6 g load during descent. At present, Soyuz TMA spacecraft are the state-of-the-art, reliable and only means of the ISS crew delivery, in-flight support and return. Introduced on the basis of many years of experience in operation of manned spacecraft were not only the principles of deep redundancy of on-board systems and equipment, but, to assure the main task of the spacecraft -the crew return to Earth -the principles of functional redundancy. That is, vital operations can be performed by different systems based on different physical principles. The emergency escape system that was developed is the only one in the world that provides crew rescue in case of LV failure at any phase in its flight. Several generations of space stations that have been developed have broadened, virtually beyond all limits, capabilities of man in space. The docking system developed at RSC Energia allowed not only to dock spacecraft in space, but also to construct in orbit various complex space systems. These include large space stations, and may include in the future the in-orbit construction of systems for the exploration of the Moon and

A flight investigation of the ultra-deep-stall descent and spin recovery characteristics of a 1/6 scale radiocontrolled model of the Piper PA38 Tomahawk

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Blanchard, W. S., Jr.

1981-01-01

Ultradeep stall descent and spin recovery characteristics of a 1/6 scale radio controlled model of the Piper PA38 Tomahawk aircraft was investigated. It was shown that the full scale PA38 is a suitable aircraft for conducting ultradeep stall research. Spin recovery was accomplished satisfactorily by entry to the ultradeep stall mode, followed by the exit from the ultradeep stall mode. It is concluded that since the PA38 has excellent spin recovery characteristics using normal recovery techniques (opposite rudder and forward control colum pressure), recovery using ultradeep stall would be beneficial only if the pilot suffered from disorientation.

Robust automatic control system of vessel descent-rise device for plant with distributed parameters “cable – towed underwater vehicle”

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Chupina, K. V.; Kataev, E. V.; Khannanov, A. M.; Korshunov, V. N.; Sennikov, I. A.

2018-05-01

The paper is devoted to a problem of synthesis of the robust control system for a distributed parameters plant. The vessel descent-rise device has a heave compensation function for stabilization of the towed underwater vehicle on a set depth. A sea state code, parameters of the underwater vehicle and cable vary during underwater operations, the vessel heave is a stochastic process. It means that the plant and external disturbances have uncertainty. That is why it is necessary to use the robust theory for synthesis of an automatic control system, but without use of traditional methods of optimization, because this cable has distributed parameters. The offered technique has allowed one to design an effective control system for stabilization of immersion depth of the towed underwater vehicle for various degrees of sea roughness and to provide its robustness to deviations of parameters of the vehicle and cable’s length.

8q24 sequence variants in relation to prostate cancer risk among men of African descent: A case-control study

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VanCleave Tiva T

2010-06-01

Full Text Available Abstract Background Human chromosome 8q24 has been implicated in prostate tumorigenesis. Methods Consequently, we evaluated seven 8q24 sequence variants relative to prostate cancer (PCA in a case-control study involving men of African descent. Genetic alterations were detected in germ-line DNA from 195 incident PCA cases and 531 controls using TaqMan polymerase chain reaction (PCR. Results Inheritance of the 8q24 rs16901979 T allele corresponded to a 2.5-fold increase in the risk of developing PCA for our test group. These findings were validated using multifactor dimensionality reduction (MDR and permutation testing (p = 0.038. The remaining 8q24 targets were not significantly related to PCA outcomes. Conclusions Although compelling evidence suggests that the 8q24 rs16901979 locus may serve as an effective PCA predictor, our findings require additional evaluation in larger studies.

Covariance Analysis Tool (G-CAT) for Computing Ascent, Descent, and Landing Errors

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Boussalis, Dhemetrios; Bayard, David S.

2013-01-01

G-CAT is a covariance analysis tool that enables fast and accurate computation of error ellipses for descent, landing, ascent, and rendezvous scenarios, and quantifies knowledge error contributions needed for error budgeting purposes. Because GCAT supports hardware/system trade studies in spacecraft and mission design, it is useful in both early and late mission/ proposal phases where Monte Carlo simulation capability is not mature, Monte Carlo simulation takes too long to run, and/or there is a need to perform multiple parametric system design trades that would require an unwieldy number of Monte Carlo runs. G-CAT is formulated as a variable-order square-root linearized Kalman filter (LKF), typically using over 120 filter states. An important property of G-CAT is that it is based on a 6-DOF (degrees of freedom) formulation that completely captures the combined effects of both attitude and translation errors on the propagated trajectories. This ensures its accuracy for guidance, navigation, and control (GN&C) analysis. G-CAT provides the desired fast turnaround analysis needed for error budgeting in support of mission concept formulations, design trade studies, and proposal development efforts. The main usefulness of a covariance analysis tool such as G-CAT is its ability to calculate the performance envelope directly from a single run. This is in sharp contrast to running thousands of simulations to obtain similar information using Monte Carlo methods. It does this by propagating the "statistics" of the overall design, rather than simulating individual trajectories. G-CAT supports applications to lunar, planetary, and small body missions. It characterizes onboard knowledge propagation errors associated with inertial measurement unit (IMU) errors (gyro and accelerometer), gravity errors/dispersions (spherical harmonics, masscons), and radar errors (multiple altimeter beams, multiple Doppler velocimeter beams). G-CAT is a standalone MATLAB- based tool intended to

Electrocardiographic patterns in African University strength and endurance athletes of Zulu descent.

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Grace, J; Duvenage, E; Jordaan, J P

2015-11-01

There is concern over the effect of training on heart function of athletes as recorded by 12-lead electrocardiography (ECG). Although ECG abnormalities with respect to ethnic origin of black athletes from the Caribbean, West Africa and East Africa have been reported, black athletes from southern Africa, specifically participating in different sports, have never been investigated before. The purpose of this study was to analyze the ECG patterns in South African students of Zulu descent, who represented our university in boxing (endurance modality) and body building (resistance modality) at a regional level. Fifteen subjects each were assigned to an endurance (E), resistance (R) or control (C) group, respectively. ECG patterns were recorded with a 12-lead ECG. Our subjects indicated no significant differences in ECG patterns in relation to whether they participate in strength or endurance related sport. However, 80% of the endurance group and 67% of the resistance displayed ECG criteria indicative of left ventricular hypertrophy (LVH), group E displays higher R5/S1-wave voltages (E=43.3 mm; R=36.8 mm; C=37.1 mm) as well distinctly abnormal ECG patterns (E=87%; R=73%; C=53%), raising clinical suspicion of structural heart disease. Our cohort presented with non-significant, marked ST-segment elevation (53% of both the E and R groups) and inverted T-waves in 27% of the E group. Similar to findings in other ethnic Africans, a large proportion of our Zulu study population displayed ECG criteria indicative of LVH on the evidence of a marked increase of R5/S1-wave voltage and ST/T-segment changes with no differences in relation to whether they participate in strength or endurance related sport.

Design optimization of single mixed refrigerant LNG process using a hybrid modified coordinate descent algorithm

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Qyyum, Muhammad Abdul; Long, Nguyen Van Duc; Minh, Le Quang; Lee, Moonyong

2018-01-01

Design optimization of the single mixed refrigerant (SMR) natural gas liquefaction (LNG) process involves highly non-linear interactions between decision variables, constraints, and the objective function. These non-linear interactions lead to an irreversibility, which deteriorates the energy efficiency of the LNG process. In this study, a simple and highly efficient hybrid modified coordinate descent (HMCD) algorithm was proposed to cope with the optimization of the natural gas liquefaction process. The single mixed refrigerant process was modeled in Aspen Hysys® and then connected to a Microsoft Visual Studio environment. The proposed optimization algorithm provided an improved result compared to the other existing methodologies to find the optimal condition of the complex mixed refrigerant natural gas liquefaction process. By applying the proposed optimization algorithm, the SMR process can be designed with the 0.2555 kW specific compression power which is equivalent to 44.3% energy saving as compared to the base case. Furthermore, in terms of coefficient of performance (COP), it can be enhanced up to 34.7% as compared to the base case. The proposed optimization algorithm provides a deep understanding of the optimization of the liquefaction process in both technical and numerical perspectives. In addition, the HMCD algorithm can be employed to any mixed refrigerant based liquefaction process in the natural gas industry.

Modified Convolutional Neural Network Based on Dropout and the Stochastic Gradient Descent Optimizer

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Jing Yang

2018-03-01

Full Text Available This study proposes a modified convolutional neural network (CNN algorithm that is based on dropout and the stochastic gradient descent (SGD optimizer (MCNN-DS, after analyzing the problems of CNNs in extracting the convolution features, to improve the feature recognition rate and reduce the time-cost of CNNs. The MCNN-DS has a quadratic CNN structure and adopts the rectified linear unit as the activation function to avoid the gradient problem and accelerate convergence. To address the overfitting problem, the algorithm uses an SGD optimizer, which is implemented by inserting a dropout layer into the all-connected and output layers, to minimize cross entropy. This study used the datasets MNIST, HCL2000, and EnglishHand as the benchmark data, analyzed the performance of the SGD optimizer under different learning parameters, and found that the proposed algorithm exhibited good recognition performance when the learning rate was set to [0.05, 0.07]. The performances of WCNN, MLP-CNN, SVM-ELM, and MCNN-DS were compared. Statistical results showed the following: (1 For the benchmark MNIST, the MCNN-DS exhibited a high recognition rate of 99.97%, and the time-cost of the proposed algorithm was merely 21.95% of MLP-CNN, and 10.02% of SVM-ELM; (2 Compared with SVM-ELM, the average improvement in the recognition rate of MCNN-DS was 2.35% for the benchmark HCL2000, and the time-cost of MCNN-DS was only 15.41%; (3 For the EnglishHand test set, the lowest recognition rate of the algorithm was 84.93%, the highest recognition rate was 95.29%, and the average recognition rate was 89.77%.

Pressure-equalizing earplugs do not prevent barotrauma on descent from 8000 ft cabin altitude.

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Klokker, Mads; Vesterhauge, Søren; Jansen, Erik C

2005-11-01

The aim of this study was to evaluate the effect of pressure-equalizing earplugs available in major airports and drugstores. No previous study has focused on preventing barotrauma using these earplugs. Blinded and double-blinded, one type of pressure-equalizing earplugs (JetEars) was studied in 27 volunteers disposed to ear barotrauma. They acted as their own controls with an active earplug in one ear and a placebo earplug in the other ear at random. All were exposed to the same well-defined pressure profile for 1 h at 8000 ft, comparable to the environment in civil commercial air travel in a pressurized cabin. Satisfaction was assessed by questionnaire and objective results were evaluated prior to and after the pressure exposure by tympanometry and otoscopy using the Teed classification. The majority of the volunteers (78%) reported a pleasant noise-reducing feeling using the earplugs. However, 75% also experienced ear pain during descent. In comparing the middle ear pressure before and after pressurization, a decrease was found in ears with both active earplugs and placebo earplugs. No difference between the active and the placebo earplugs were found. Furthermore, after evaluation of the two groups of ears using otoscopy, no prevention of barotrauma was found. In fact, the ears using an active pressure-equalizing earplug scored significantly worse (p = 0.033). Feelings of noise reduction were reported, but no prevention of barotrauma could be demonstrated with the use of pressure-equalizing earplugs. Pressure-equalizing earplugs cannot be recommended in air travel for preventing ear barotrauma.

Metabolic responses to a traditional Mexican diet compared with a commonly consumed US diet in women of Mexican descent: a randomized crossover feeding trial.

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Santiago-Torres, Margarita; Kratz, Mario; Lampe, Johanna W; Tapsoba, Jean De Dieu; Breymeyer, Kara L; Levy, Lisa; Villaseñor, Adriana; Wang, Ching-Yun; Song, Xiaoling; Neuhouser, Marian L

2016-02-01

Mexican immigrants are disproportionally affected by diet-related risk of metabolic dysfunction. Whether adhering to a traditional Mexican diet or adopting a US diet contributes to metabolic changes associated with future risk of type 2 diabetes and other chronic diseases has not been investigated. The purpose of this study was to test in a randomized crossover feeding trial the metabolic responses to a Mexican diet compared with a commonly consumed US diet. First- and second-generation healthy women of Mexican descent (n = 53) were randomly assigned in a crossover design to consume a Mexican or US diet for 24 d each, separated by a 28-d washout period. Diets were eucaloric and similar in macronutrient composition. The metabolic responses to diets were assessed by measuring fasting serum concentrations of glucose, insulin, insulin-like growth factor 1 (IGF-1), insulin-like growth factor binding protein 3 (IGFBP-3), adiponectin, C-reactive protein (CRP), and interleukin 6 (IL-6), as well as the homeostasis model assessment of insulin resistance (HOMA-IR) at the beginning and end of each period. Linear mixed models tested the intervention effect on the biomarkers, while adjusting for diet sequence, feeding period, baseline and washout biomarker concentrations, age, acculturation, and BMI. Compared with the US diet, the Mexican diet reduced insulin by 14% [geometric means (95% CIs): 9.3 (8.3, 10.3) compared with 8.0 (7.2, 8.9) μU/mL; P = 0.02], HOMA-IR by 15% [2.0 (1.8, 2.3) compared with 1.7 (1.6, 2.0); P = 0.02], and IGFBP-3 by 6% (mean ± SEM: 2420 ± 29 compared with 2299 ± 29 ng/mL; P diet. Compared with the commonly consumed US diet, the traditional Mexican diet modestly improved insulin sensitivity under conditions of weight stability in healthy women of Mexican descent, while having no impact on biomarkers of inflammation. This trial was registered at clinicaltrials.gov as NCT01369173. © 2016 American Society for Nutrition.

Tu Salud, ¡Si Cuenta!: Exposure to a community-wide campaign and its associations with physical activity and fruit and vegetable consumption among individuals of Mexican descent.

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Reininger, Belinda M; Mitchell-Bennett, Lisa; Lee, MinJae; Gowen, Rose Z; Barroso, Cristina S; Gay, Jennifer L; Saldana, Mayra Vanessa

2015-10-01

Mexican Americans along the US-Mexico border have been found to be disproportionately affected by chronic diseases particularly related to lack of physical activity and healthful food choices. A community-wide campaign (CWC) is an evidence-based strategy to address these behaviors but with few examples of implementation in Mexican descent populations facing profound health disparities. We examined exposure to a CWC, titled Tu Salud ¡Sí Cuenta!, and its association with meeting the recommended minutes of moderate and vigorous physical activity weekly and consuming more portions of fruits and vegetables daily. A cross-sectional sample of 1438 Mexican descent participants was drawn from a city-wide, randomly-selected cohort interviewed between the years 2008 and 2012. Multivariable comparisons of participants exposed and not exposed to the CWC and meeting physical activity guidelines or their fruit and vegetable consumptions using mixed effects models were conducted. The community-wide campaign components included different forms of mass media and individually-focused components such as community health worker (CHW) home visits. After adjusting for gender, age, marital status, educational attainment, language preference, health insurance, and diabetes diagnosis, the strongest association was found between meeting physical activity guidelines and exposure to both CHW discussions and radio messages (adjusted OR = 3.83; 95% CI = [1.28, 6.21]; p = 0.0099). Participants who reported exposure to both radio and TV messages consumed more portions of fruits and vegetables than those who reported no exposure (adjusted RR = 1.30; 95% CI = [1.02, 1.66]; p = 0.0338). This study provides insights into the implementation and behavioral outcomes associated with exposure to a community-wide campaign, a potential model for addressing lifestyle modifications in populations affected by health disparities. Copyright © 2015 Elsevier Ltd. All rights reserved.

Hip biomechanics during stair ascent and descent in people with and without hip osteoarthritis.

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Hall, Michelle; Wrigley, Tim V; Kean, Crystal O; Metcalf, Ben R; Bennell, Kim L

2017-07-01

Hip osteoarthritis (OA) is often associated with pain and impaired function. Understanding biomechanical alterations in patients with hip OA during challenging activities such as stair use is important to inform treatments. The aim of this study was to determine whether kinematics and kinetics during stair ambulation differed between people with hip OA and healthy controls. Fifteen participants with symptomatic and radiographic hip OA and 15 asymptomatic healthy controls underwent 3-D motion analysis during stair ascent and descent. Trunk, pelvis, and hip kinematics as well as hip kinetics were evaluated. Analyses were performed unadjusted and adjusted for speed and leg length. In both the unadjusted and adjusted analyses, participants with hip OA ascended stairs with less hip range of motion in all three planes and a lower peak external rotation moment compared to controls. In the unadjusted analysis, hip OA participants descended stairs with greater ipsilateral trunk lean, less sagittal plane range of motion, lower peak extension moment, lower peak external rotation moment, and greater hip adduction moment impulse compared to controls. In the adjusted results, peak internal rotation moment and hip adduction moment impulse were greater in hip OA participants compared to controls. Findings show that individuals with hip OA display limited range of hip joint movement, particularly during stair ascent, and overall indicate the use of strategies (e.g., trunk lean; lower peak external rotation moment; higher adduction moment impulse) that implicate altered hip abductor function. Future research is required to further understand the implications of these findings on hip OA. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:1505-1514, 2017. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

Custom genotyping for substance addiction susceptibility genes in Jordanians of Arab descent

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AL-Eitan Laith N

2012-09-01

Full Text Available Abstract Background Both environmental and genetic factors contribute to individual susceptibility to initiation of substance use and vulnerability to addiction. Determining genetic risk factors can make an important contribution to understanding the processes leading to addiction. In order to identify gene(s and mechanisms associated with substance addiction, a custom platform array search for a genetic association in a case/control of homogenous Jordanian Arab population was undertaken. Patients meeting the DSM-VI criteria for substance dependence (n = 220 and entering eight week treatment program at two Jordanian Drug Rehabilitation Centres were genotyped. In addition, 240 healthy controls were also genotyped. The sequenom MassARRAY system (iPLEX GOLD was used to genotype 49 single nucleotide polymorphisms (SNPs within 8 genes (DRD1, DRD2, DRD3, DRD4, DRD5, BDNF, SLC6A3 and COMT. Results This study revealed six new associations involving SNPs within DRD2 gene on chromosome 11. These six SNPs within the DRD2 were found to be most strongly associated with substance addiction in the Jordanian Arabic sample. The strongest statistical evidence for these new association signals were from rs1799732 in the C/−C promoter and rs1125394 in A/G intron 1 regions of DRD2, with the overall estimate of effects returning an odds ratio of 3.37 (χ2 (2, N = 460 = 21, p-value = 0.000026 and 1.78 (χ2 (2, N = 460 = 8, p-value = 0.001, respectively. It has been suggested that DRD2, dopamine receptor D2, plays an important role in dopamine secretion and the signal pathways of dopaminergic reward and drug addiction. Conclusion This study is the first to show a genetic link to substance addiction in a Jordanian population of Arab descent. These findings may contribute to our understanding of drug addiction mechanisms in Middle Eastern populations and how to manage or dictate therapy for individuals. Comparative analysis with different

Characteristics of US-Born Versus Foreign-Born Americans of African Descent With Chronic Hepatitis B.

Science.gov (United States)

Hassan, Mohamed A; Kim, W Ray; Li, Ruosha; Smith, Coleman I; Fried, Michael W; Sterling, Richard K; Ghany, Marc G; Wahed, Abdus S; Ganova-Raeva, Lilia M; Roberts, Lewis R; Lok, Anna S F

2017-08-01

Hepatitis B virus (HBV) infection is more common in African Americans than in white Americans. We compared the epidemiologic, clinical, and virological characteristics of US-born African Americans (USAAs) to those of foreign-born African Americans (FBAAs) with chronic hepatitis B. The adult cohort study of the Hepatitis B Research Network enrolls patients with HBV infection from 21 clinical sites in the United States and Canada. A total of 237 (15%) of the adult participants with chronic HBV infection that were enrolled from January 20, 2011, to October 2, 2013, were of African descent, including 57 USAAs and 180 FBAAs (76%). Compared with FBAAs, USAAs were older and more likely to have acquired HBV through sexual exposure, to be HBeAg-positive, to have higher HBV DNA levels, and to be infected with HBV genotype A2. FBAAs from West Africa were more likely to have elevated serum alanine aminotransferase (72% vs. 50%; P < 0.01) and higher HBV DNA levels (median, 3.2 log10 IU/mL vs. 2.8 log10 IU/mL; P = 0.03) compared with East African FBAAs. The predominant HBV genotype among West African FBAAs was E (67%), whereas genotypes A (78%) and D (16%) were common in East African FBAAs. Significant differences were found between USAAs and FBAAs, highlighting the need for tailored strategies for prevention and management of chronic HBV infection for African Americans. © The Author(s) 2017. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Value of MRI in the diagnosis of stress urinary incontinence in the absence of organ descent

International Nuclear Information System (INIS)

Beyersdorff, D.; Taupitz, M.; Fischer, T.; Hamm, B.; Tunn, R.; Rieprich, M.

2001-01-01

To detect pathomorphological changes of the pelvic floor, the vagina, and the urethra by MR imaging in patients with stress urinary incontinence in the absence of organ descent compared with findings in 10 healthy controls. Materials and Methods: The study included 10 healthy controls and 38 patients with stage II urinary incontinence showing no urge symptoms but a pathological stress profile on urodynamic testing. The subjects underwent MR imaging with a phased-array coil at 1.5 T in addition to urodynamic testing and gynecological examination. The following sequences were used: axial and coronal PD-weighted TSE sequences with a FOV of 20 cm and a section thickness of 4 mm; axial STIR sequence. Sagittal T 2 -weighted HASTE sequences were acquired during pelvic floor contraction, relaxation, and straining maneuvers. Results: In 22/38 cases pathomorphological changes were found by MR imaging. The pathomorphological changes were classified as lateral defects (n = 14) if the musculofascial connection between the levator muscle and the lateral vaginal wall or the butterfly shape of the vagina was absent and as central (n = 16) if changes were detected in the urethral wall. Defects of the pelvic floor muscles were detected in 8 cases. No underlying changes were identified in 16/38 cases. Conclusion: In cases of female urinary incontinence, MR imaging of the pelvic floor can detect pathomorphological changes, which are difficult to identify by clinical examination. MR imaging currently does not allow the detection of morphological changes in all forms of female urinary stress incontinence. (orig.) [de

Insulin resistance in Chileans of European and indigenous descent: evidence for an ethnicity x environment interaction.

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Celis-Morales, Carlos A; Perez-Bravo, Francisco; Ibañes, Luis; Sanzana, Ruth; Hormazabal, Edison; Ulloa, Natalia; Calvo, Carlos; Bailey, Mark E S; Gill, Jason M R

2011-01-01

Effects of urbanisation on diabetes risk appear to be greater in indigenous populations worldwide than in populations of European origin, but the reasons are unclear. This cross-sectional study aimed to determine whether the effects of environment (Rural vs. Urban), adiposity, fitness and lifestyle variables on insulin resistance differed between individuals of indigenous Mapuche origin compared to those of European origin in Chile. 123 Rural Mapuche, 124 Urban Mapuche, 91 Rural European and 134 Urban European Chilean adults had blood taken for determination of HOMA-estimated insulin resistance (HOMA(IR)) and underwent assessment of physical activity/sedentary behaviour (using accelerometry), cardiorespiratory fitness, dietary intake and body composition. General linear models were used to determine interactions with ethnicity for key variables. There was a significant "ethnicity x environment" interaction for HOMA(IR) (Mean±SD; Rural Mapuche: 1.65±2.03, Urban Mapuche: 4.90±3.05, Rural European: 0.82±0.61, Urban European: 1.55±1.34, p((interaction)) = 0.0003), such that the effect of urbanisation on HOMA(IR) was greater in Mapuches than Europeans. In addition, there were significant interactions (all pMapuches compared to Europeans, an observation that persisted after adjustment for potential confounders. Urbanisation, adiposity, physical activity and sedentary behaviour influence insulin resistance to a greater extent in Chilean Mapuches than Chileans of European descent. These findings have implications for the design and implementation of lifestyle strategies to reduce metabolic risk in different ethnic groups, and for understanding of the mechanisms underpinning human insulin resistance.

Multicenter Study of Human Papillomavirus and the Human Papillomavirus Vaccine: Knowledge and Attitudes among People of African Descent

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Elizabeth Blackman

2013-01-01

Full Text Available Objective. To compare knowledge and attitudes of human papillomavirus (HPV and the vaccine between different cultures of African descent. Methods. A cross-sectional survey of 555 African-Americans and Afro-Caribbeans residing in the US and the Bahamas (BHM was conducted. Results. General knowledge about HPV and the HPV vaccine differed between the two countries significantly. Bahamian respondents were less likely to have higher numbers of correct knowledge answers when compared to Americans (Adjusted Odds Ratio [Adj. OR] 0.47, 95% Confidence Interval [CI] 0.30–0.75. Older age, regardless of location, was also associated with answering fewer questions correctly (Adj. OR 0.61, 95% CI 0.40–0.92. Attitudes related to HPV vaccination were similar between the US and BHM, but nearly 80% of BHM respondents felt that children should not be able to receive the vaccine without parental consent compared to 57% of American respondents. Conclusions. Grave lack of knowledge, safety and cost concerns, and influence of parental restrictions may negatively impact vaccine uptake among African-American and Afro-Caribbean persons. Interventions to increase the vaccine uptake in the Caribbean must include medical provider and parental involvement. Effective strategies for education and increasing vaccine uptake in BHM are crucial for decreasing cervical cancer burden in the Caribbean.

TRW - Lunar Descent Engine. Chapter 6, Appendix H

Science.gov (United States)

Elverum, Gerard W.

2009-01-01

it came to Apollo 13, we went back into the record, and said, "Hey, we have pushed this system around up there on Apollo 5, and we have also restarted this tandem configuration." The requirements on Apollo 13 were to put it back into play. The spacecraft was out of free return to the earth at the time of the accident. It would not have come back. NASA said, "Okay, we ll use the descent engine to put the spacecraft in a free trajectory; it will go around the moon and be on free trajectory back to Earth." Then, as it came around the far side of the moon, the guys found out that they had an oxygen problem. As you remember, things were getting pretty bad in there. They said, "We ve got to get it back as fast as we can. Is it okay if we re-fire the engine? Now, we re in a free trajectory, so we want to put as much delta-v (or change in velocity) in as we can. Can we re-fire right now?" We said, "Yes, the data says it has been this period of time." We could re-fire the engine, run the rest of the duty cycle up as far as we needed while preserving enough fluids to make the final correction as the spacecraft got near Earth, and restart the engine. It was pretty fortuitous that we could give them those answers.

Optimum input leads for cryogenic apparatus; Optimisation des descentes de courant dans des enceintes cryogeniques

Energy Technology Data Exchange (ETDEWEB)

Der Nigohossian, G [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1967-02-15

The electrical leads used to introduce a current into a cryostat cause a heat influx due to thermal conduction and to Joule heating. It is very important to be able to minimize this flux. Theoretical calculation of optimized leads takes into account the varying heat and electrical conductivities of the leads as well as the heat exchange coefficient with the effluent gas. Practical results have been summarized in different tables which permit for a specific material i.e. copper, aluminium, brass, stainless steel with the intensity and end temperatures being known (i.e. 4,2 or 18,5 deg. K at the cold end; 77,295 or 320 deg. K at the warm end) to deduce the minimum heat flow and the length-cross section ratio of the optimized leads. A general method is indicated, which would allow to solve the same problem for other materials. (author) [French] Les conducteurs electriques assurant la liaison d'appareillages situes dans des cryostats apportent tant par effet Joule que par conductibilite thermique une certaine quantite de chaleur qu'il est tres important de pouvoir minimiser. L'etude theorique de l'optimisation des descentes de courant tient compte des variations des conductibilites thermique et electrique ainsi que de l'influence des echanges avec le gaz. Pratiquement les resultats ont ete resumes dans differents tableaux ce qui permet, pour un materiau donne tel que cuivre, aluminium, laiton, acier inoxydable, connaissant l'intensite et les temperatures d'extremites 4,2 et 18,5 deg. K d'une part, et 77,295 et 330 deg. K d'autre part, de deduire la consommation minimale et le rapport longueur-section d'un conducteur optimise. Une methode generale est indiquee, qui permet de resoudre le probleme pour d'autres materiaux. (auteur)

The Terminology Denoting Political Organisation and Common Descent in the Däftär-i Čingiz-nāmä

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Danka B.

2017-12-01

Full Text Available Research objective and materials: The paper examines selected lists of terminologies which define certain features (common descent and political organisation of ethnic identity in the Däftär-i Čingiz-nāmä. These words often occur in coordinate compounds in the text. Compounding is not very well researched in Turkic linguistics, nor was it being considered in earlier philological works on Turkic historical texts. The author defines the problem of identification of such compounds in the text, and offers a morpho-syntactic criterion which can be used as a tool for identification. Novelty and results of the research: Based on the semantic relation between the compound’s components, the author distinguishes two types: Those compounds, the components of which have identical meaning: These were probably used for elaborate speech. Those compounds, the components of which do not have identical meaning: These arrived at a new, different concept from the components’ meaning. Three such compounds have been identified, which more or less arrive at a similar concept to ethnos. Finally, the author compares the meaning of these compounds to that of Old Turkic bodun – ‘people’, and el – ‘realm’.

Exploring Identity-By-Descent Segments and Putative Functions Using Different Foundation Parents in Maize.

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Xun Wu

Full Text Available Maize foundation parents (FPs play no-alternative roles in hybrid breeding because they were widely used in the development of new lines and hybrids. The combination of different identity-by-descent (IBD segments and genes could account for the formation patterns of different FPs, and knowledge of these IBD regions would provide an extensive foundation for the development of new candidate FP lines in future maize breeding. In this paper, a panel of 304 elite lines derived from FPs, i.e., B73, 207, Mo17, and Huangzaosi (HZS, was collected and analyzed using 43,252 single nucleotide polymorphism (SNP markers. Most IBD segments specific to particular FP groups were identified, including 116 IBD segments in B73, 105 in Mo17, 111 in 207, and 190 in HZS. In these regions, 423 quantitative trait nucleotides (QTNs associated with 15 agronomic traits and 804 candidate genes were identified. Some known adaptation-related genes, e.g., dwarf8 and vgt1 in HZS, zcn8 and epc in Mo17, and ZmCCT in 207, were validated as being tightly linked to particular IBD segments. In addition, numerous new candidate genes were also identified. For example, GRMZM2G154278 in HZS, which belongs to the cell cycle control family, was closely linked to a QTN of the ear height/plant height (EH/PH trait; GRMZM2G051943 in 207, which encodes an endochitinase precursor (EP chitinase, was closely linked to a QTN for kernel density; and GRMZM2G170586 in Mo17 was closely linked to a QTN for ear diameter. Complex correlations among these genes were also found. Many IBD segments and genes were included in the formation of FP lines, and complex regulatory networks exist among them. These results provide new insights on the genetic basis of complex traits and provide new candidate IBD regions or genes for the improvement of special traits in maize production.

Full cyclic coordinate descent: solving the protein loop closure problem in Cα space

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Hamelryck Thomas

2005-06-01

Full Text Available Abstract Background Various forms of the so-called loop closure problem are crucial to protein structure prediction methods. Given an N- and a C-terminal end, the problem consists of finding a suitable segment of a certain length that bridges the ends seamlessly. In homology modelling, the problem arises in predicting loop regions. In de novo protein structure prediction, the problem is encountered when implementing local moves for Markov Chain Monte Carlo simulations. Most loop closure algorithms keep the bond angles fixed or semi-fixed, and only vary the dihedral angles. This is appropriate for a full-atom protein backbone, since the bond angles can be considered as fixed, while the (φ, ψ dihedral angles are variable. However, many de novo structure prediction methods use protein models that only consist of Cα atoms, or otherwise do not make use of all backbone atoms. These methods require a method that alters both bond and dihedral angles, since the pseudo bond angle between three consecutive Cα atoms also varies considerably. Results Here we present a method that solves the loop closure problem for Cα only protein models. We developed a variant of Cyclic Coordinate Descent (CCD, an inverse kinematics method from the field of robotics, which was recently applied to the loop closure problem. Since the method alters both bond and dihedral angles, which is equivalent to applying a full rotation matrix, we call our method Full CCD (FCDD. FCCD replaces CCD's vector-based optimization of a rotation around an axis with a singular value decomposition-based optimization of a general rotation matrix. The method is easy to implement and numerically stable. Conclusion We tested the method's performance on sets of random protein Cα segments between 5 and 30 amino acids long, and a number of loops of length 4, 8 and 12. FCCD is fast, has a high success rate and readily generates conformations close to those of real loops. The presence of constraints

Estimates of visibility of the surface of Venus from descent probes and balloons

Science.gov (United States)

Moroz, V. I.

2002-03-01

One of the tasks of future missions to Venus could be imaging of the surface either from a probe during its descent or from a balloon that drifts at a definite height below the main cloud deck. The undercloud atmosphere restricts capabilities of this experiment in three ways: (1) true absorption in bands of CO 2 and H 2O, (2) gaseous Rayleigh scattering, and (3) scattering and absorption by the undercloud haze. The first and second are dominant, at least below 30- 35 km. Wavelength 1.02 μm seems to be the most favorable as the centre of a window for imaging because the true (band) absorption and Rayleigh optical depth are minimal here. It is also important that this wavelength is within the range of silicon CCD spectral sensitivity. Wavelengths 0.85 and 0.65 μm are included in the analysis. A special number (the visibility factor) is introduced for the quantitative estimates of the atmospheric influence on the quality of surface images. Results of Venera 13 and 14 are used as key information about the optical properties of the atmosphere of Venus. Two cases are discussed: (1) imaging during the daytime in all three windows and (2) night imaging in 1 μm window using the thermal emission of the surface. It is shown that at daytime 3-color imaging with the use of all three windows would be difficult from heights more than a few kilometers, but in 1 μm the approximate upper limit is about 15 km. Visibility of highlands will be better. Night conditions are better for imaging: pictures in 1 μm window. Night images may have acceptable quality just after the passage of the lower boundary of the main cloud deck (48- 50 km). However, interpretation may meet difficulties due to mixing effects of temperatures and emissivity surface fields. NIR surface mapping from orbiters is possible, but it will not provide space resolution better than about 50- 100 km. This mapping will deliver information about surface temperature (linked with topography). Constraints on the mineral

A TLBO based gradient descent learning-functional link higher order ANN: An efficient model for learning from non-linear data

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Bighnaraj Naik

2018-01-01

Full Text Available All the higher order ANNs (HONNs including functional link ANN (FLANN are sensitive to random initialization of weight and rely on the learning algorithms adopted. Although a selection of efficient learning algorithms for HONNs helps to improve the performance, on the other hand, initialization of weights with optimized weights rather than random weights also play important roles on its efficiency. In this paper, the problem solving approach of the teaching learning based optimization (TLBO along with learning ability of the gradient descent learning (GDL is used to obtain the optimal set of weight of FLANN learning model. TLBO does not require any specific parameters rather it requires only some of the common independent parameters like number of populations, number of iterations and stopping criteria, thereby eliminating the intricacy in selection of algorithmic parameters for adjusting the set of weights of FLANN model. The proposed TLBO-FLANN is implemented in MATLAB and compared with GA-FLANN, PSO-FLANN and HS-FLANN. The TLBO-FLANN is tested on various 5-fold cross validated benchmark data sets from UCI machine learning repository and analyzed under the null-hypothesis by using Friedman test, Holm’s procedure and post hoc ANOVA statistical analysis (Tukey test & Dunnett test.

Insulin resistance in Chileans of European and indigenous descent: evidence for an ethnicity x environment interaction.

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Carlos A Celis-Morales

Full Text Available BACKGROUND: Effects of urbanisation on diabetes risk appear to be greater in indigenous populations worldwide than in populations of European origin, but the reasons are unclear. This cross-sectional study aimed to determine whether the effects of environment (Rural vs. Urban, adiposity, fitness and lifestyle variables on insulin resistance differed between individuals of indigenous Mapuche origin compared to those of European origin in Chile. METHODOLOGY/PRINCIPAL FINDINGS: 123 Rural Mapuche, 124 Urban Mapuche, 91 Rural European and 134 Urban European Chilean adults had blood taken for determination of HOMA-estimated insulin resistance (HOMA(IR and underwent assessment of physical activity/sedentary behaviour (using accelerometry, cardiorespiratory fitness, dietary intake and body composition. General linear models were used to determine interactions with ethnicity for key variables. There was a significant "ethnicity x environment" interaction for HOMA(IR (Mean±SD; Rural Mapuche: 1.65±2.03, Urban Mapuche: 4.90±3.05, Rural European: 0.82±0.61, Urban European: 1.55±1.34, p((interaction = 0.0003, such that the effect of urbanisation on HOMA(IR was greater in Mapuches than Europeans. In addition, there were significant interactions (all p<0.004 with ethnicity for effects of adiposity, sedentary time and physical activity on HOMA(IR, with greater effects seen in Mapuches compared to Europeans, an observation that persisted after adjustment for potential confounders. CONCLUSIONS/SIGNIFICANCE: Urbanisation, adiposity, physical activity and sedentary behaviour influence insulin resistance to a greater extent in Chilean Mapuches than Chileans of European descent. These findings have implications for the design and implementation of lifestyle strategies to reduce metabolic risk in different ethnic groups, and for understanding of the mechanisms underpinning human insulin resistance.

Descent and mixing of the overflow plume from Storfjord in Svalbard: an idealized numerical model study

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I. Fer

2008-05-01

Full Text Available Storfjorden in the Svalbard Archipelago is a sill-fjord that produces significant volumes of dense, brine-enriched shelf water through ice formation. The dense water produced in the fjord overflows the sill and can reach deep into the Fram Strait. For conditions corresponding to a moderate ice production year, the pathway of the overflow, its descent and evolving water mass properties due to mixing are investigated for the first time using a high resolution 3-D numerical model. An idealized modeling approach forced by a typical annual cycle of buoyancy forcing due to ice production is chosen in a terrain-following vertical co-ordinate. Comparison with observational data, including hydrography, fine resolution current measurements and direct turbulence measurements using a microstructure profiler, gives confidence on the model performance. The model eddy diffusivity profiles contrasted to those inferred from the turbulence measurements give confidence on the skill of the Mellor Yamada scheme in representing sub-grid scale mixing for the Storfjorden overflow, and probably for gravity current modeling, in general. The Storfjorden overflow is characterized by low Froude number dynamics except at the shelf break where the plume narrows, accelerates with speed reaching 0.6 m s⁻¹, yielding local Froude number in excess of unity. The volume flux of the plume increases by five-fold from the sill to downstream of the shelf-break. Rotational hydraulic control is not applicable for transport estimates at the sill using upstream basin information. To the leading order, geostrophy establishes the lateral slope of the plume interface at the sill. This allows for a transport estimate that is consistent with the model results by evaluating a weir relation at the sill.

Relationship of beliefs, epistemology, and alternate conceptions to college student understanding of evolution and common descent

Science.gov (United States)

Miller, Joyce Catherine

Quantitative and qualitative methodologies were combined to explore the relationships between an understanding of evolution and 4 epistemology factors: (a) control of learning, (b) speed of learning , (c) stability of knowledge, and (d) belief in evolution/creationism. A 17-item instrument was developed that reliably measured a belief in creationism and subtle differences between this belief and an acceptance of evolution. The subjects were 45 students enrolled in a biology course at a 2-year community college. Evolution was taught in a traditional format, and common descent was taught in an inquiry-based laboratory session consisting of: (a) a comparison of hemoglobin DNA sequences of the human, chimpanzee, and gorilla; and (b) a comparison of 8 primate skull casts, including the modern human, chimpanzee, gorilla, and five prehistoric fossils. Prior to instruction the students completed an epistemology questionnaire and a knowledge test about evolution. Five weeks after instruction, the students completed a posttest. A t-test revealed no differences between the pretest and the posttest. However, the group of students that scored higher on the posttest than on the pretest was found to have a stronger belief in the uncertainty of knowledge. Pearson r was computed to check for relationships between the 4 epistemological factors and the understanding of evolution. There was a significant relationship between a belief in creationism and a lessor understanding of evolution as measured on both the pretest and the posttest (ps humans evolved from the chimpanzee. Additionally, students grouped the 8 primate skulls into just 2 categories: human and animals. Other misconceptions included a nonevolutionary use of the term, related, and the use of naive organizers leading to incorrect conclusions about the relatedness of certain organisms, such as a connection between fish and whales. These organizers included: (a) similarity of traits, (b) environment, (c) relative size, (d

A moving fluoroscope to capture tibiofemoral kinematics during complete cycles of free level and downhill walking as well as stair descent.

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Renate List

Full Text Available Videofluoroscopy has been shown to provide essential information in the evaluation of the functionality of total knee arthroplasties. However, due to the limitation in the field of view, most systems can only assess knee kinematics during highly restricted movements. To avoid the limitations of a static image intensifier, a moving fluoroscope has been presented as a standalone system that allows tracking of the knee during multiple complete cycles of level- and downhill-walking, as well as stair descent, in combination with the synchronous assessment of ground reaction forces and whole body skin marker measurements. Here, we assess the ability of the system to keep the knee in the field of view of the image intensifier. By measuring ten total knee arthroplasty subjects, we demonstrate that it is possible to maintain the knee to within 1.8 ± 1.4 cm vertically and 4.0 ± 2.6 cm horizontally of the centre of the intensifier throughout full cycles of activities of daily living. Since control of the system is based on real-time feedback of a wire sensor, the system is not dependent on repeatable gait patterns, but is rather able to capture pathological motion patterns with low inter-trial repeatability.

A moving fluoroscope to capture tibiofemoral kinematics during complete cycles of free level and downhill walking as well as stair descent.

Science.gov (United States)

List, Renate; Postolka, Barbara; Schütz, Pascal; Hitz, Marco; Schwilch, Peter; Gerber, Hans; Ferguson, Stephen J; Taylor, William R

2017-01-01

Videofluoroscopy has been shown to provide essential information in the evaluation of the functionality of total knee arthroplasties. However, due to the limitation in the field of view, most systems can only assess knee kinematics during highly restricted movements. To avoid the limitations of a static image intensifier, a moving fluoroscope has been presented as a standalone system that allows tracking of the knee during multiple complete cycles of level- and downhill-walking, as well as stair descent, in combination with the synchronous assessment of ground reaction forces and whole body skin marker measurements. Here, we assess the ability of the system to keep the knee in the field of view of the image intensifier. By measuring ten total knee arthroplasty subjects, we demonstrate that it is possible to maintain the knee to within 1.8 ± 1.4 cm vertically and 4.0 ± 2.6 cm horizontally of the centre of the intensifier throughout full cycles of activities of daily living. Since control of the system is based on real-time feedback of a wire sensor, the system is not dependent on repeatable gait patterns, but is rather able to capture pathological motion patterns with low inter-trial repeatability.

A moving fluoroscope to capture tibiofemoral kinematics during complete cycles of free level and downhill walking as well as stair descent

Science.gov (United States)

Postolka, Barbara; Schütz, Pascal; Hitz, Marco; Schwilch, Peter; Gerber, Hans

2017-01-01

Videofluoroscopy has been shown to provide essential information in the evaluation of the functionality of total knee arthroplasties. However, due to the limitation in the field of view, most systems can only assess knee kinematics during highly restricted movements. To avoid the limitations of a static image intensifier, a moving fluoroscope has been presented as a standalone system that allows tracking of the knee during multiple complete cycles of level- and downhill-walking, as well as stair descent, in combination with the synchronous assessment of ground reaction forces and whole body skin marker measurements. Here, we assess the ability of the system to keep the knee in the field of view of the image intensifier. By measuring ten total knee arthroplasty subjects, we demonstrate that it is possible to maintain the knee to within 1.8 ± 1.4 cm vertically and 4.0 ± 2.6 cm horizontally of the centre of the intensifier throughout full cycles of activities of daily living. Since control of the system is based on real-time feedback of a wire sensor, the system is not dependent on repeatable gait patterns, but is rather able to capture pathological motion patterns with low inter-trial repeatability. PMID:29016647

A novel three-dimensional dynamic anorectal ultrasonography technique for the assessment of perineal descent, compared with defaecography.

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Murad-Regadas, S M; dos Santos, D; Soares, G; Regadas, F S P; Rodrigues, L V; Buchen, G; Kenmoti, V T; Surimã, W S; Fernandes, G O da S

2012-06-01

The purpose of the study was to describe a novel three-dimensional dynamic anorectal ultrasonography technique (dynamic 3-DAUS) for assessment of perineal descent (PD) and establishment of normal range values, comparing it with defaecography. Secondarily, the study compares the ability of the two techniques to identify various pelvic floor dysfunctions. A prospective study was undertaken in 29 women (mean age 43 years) with obstructed defecation disorder. All patients underwent defaecography and dynamic 3-DAUS and the results were compared. Lee kappa coefficients (K) were used. On defaecography, PD > 3 cm was detected in 12 patients. On dynamic 3-DAUS, 10 of these patients had PD > 2.5 cm. Seventeen had normal PD on defaecography and PD ≤ 2.5 cm on dynamic 3-DAUS (K 0.85). Normal relaxation was observed in 10 patients and anismus in 14 with both techniques (K 0.65). Both techniques identified five patients without rectocele, two with grade I rectocele (K 0.89 and 1.00, respectively) and 10 with grade II and nine with grade III (K 0.72 and 0.77, respectively). Rectal intussusception was identified in six patients on defaecography. These were confirmed on dynamic 3-DAUS in addition to the identification of another seven cases indicating moderate agreement (K 0.46). Enterocele/sigmoidocele grade III was identified in one patient with both techniques, indicating substantial agreement (K 0.65). Dynamic 3-DAUS was shown to be a reliable technique for the assessment of PD and pelvic floor dysfunctions, identifying all disorders and confirming findings from defaecography. © 2011 The Authors. Colorectal Disease © 2011 The Association of Coloproctology of Great Britain and Ireland.

The single-breath diffusing capacity of CO and NO in healthy children of European descent.

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Thomas, Astrid; Hanel, Birgitte; Marott, Jacob L; Buchvald, Frederik; Mortensen, Jann; Nielsen, Kim G

2014-01-01

The diffusing capacity (DL) of the lung can be divided into two components: the diffusing capacity of the alveolar membrane (Dm) and the pulmonary capillary volume (Vc). DL is traditionally measured using a single-breath method, involving inhalation of carbon monoxide, and a breath hold of 8-10 seconds (DL,CO). This method does not easily allow calculation of Dm and Vc. An alternative single-breath method (DL,CO,NO), involving simultaneous inhalation of carbon monoxide and nitric oxide, and traditionally a shorter breath hold, allows calculation of Dm and Vc and the DL,NO/DL,CO ratio in a single respiratory maneuver. The clinical utility of Dm, Vc, and DL,NO/DL,CO in the pediatric age range is currently unknown but also restricted by lack of reference values. The aim of this study was to establish reference ranges for the outcomes of DL,CO,NO with a 5 second breath hold, including the calculated outcomes Dm, Vc, and the DL,NO/DL,CO ratio, as well as to establish reference values for the outcomes of the traditional DL,CO method, with a 10 second breath hold in children. DL,CO,NO and DL,CO were measured in healthy children, of European descent, aged 5-17 years using a Jaeger Masterscreen PFT. The data were analyzed using the Generalized Additive Models for Location Scale and Shape (GAMLSS) statistical method. A total of 326 children were eligible for diffusing capacity measurements, resulting in 312 measurements of DL,CO,NO and 297 of DL,CO, respectively. Reference equations were established for the outcomes of DL,CO,NO and DL,CO, including the calculated values: Vc, Dm, and the DL,NO/DL,CO ratio. These reference values are based on the largest sample of children to date and may provide a basis for future studies of their clinical utility in differentiating between alterations in the pulmonary circulation and changes in the alveolar membrane in pediatric patients.

The single-breath diffusing capacity of CO and NO in healthy children of European descent.

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Astrid Thomas

Full Text Available The diffusing capacity (DL of the lung can be divided into two components: the diffusing capacity of the alveolar membrane (Dm and the pulmonary capillary volume (Vc. DL is traditionally measured using a single-breath method, involving inhalation of carbon monoxide, and a breath hold of 8-10 seconds (DL,CO. This method does not easily allow calculation of Dm and Vc. An alternative single-breath method (DL,CO,NO, involving simultaneous inhalation of carbon monoxide and nitric oxide, and traditionally a shorter breath hold, allows calculation of Dm and Vc and the DL,NO/DL,CO ratio in a single respiratory maneuver. The clinical utility of Dm, Vc, and DL,NO/DL,CO in the pediatric age range is currently unknown but also restricted by lack of reference values.The aim of this study was to establish reference ranges for the outcomes of DL,CO,NO with a 5 second breath hold, including the calculated outcomes Dm, Vc, and the DL,NO/DL,CO ratio, as well as to establish reference values for the outcomes of the traditional DL,CO method, with a 10 second breath hold in children.DL,CO,NO and DL,CO were measured in healthy children, of European descent, aged 5-17 years using a Jaeger Masterscreen PFT. The data were analyzed using the Generalized Additive Models for Location Scale and Shape (GAMLSS statistical method.A total of 326 children were eligible for diffusing capacity measurements, resulting in 312 measurements of DL,CO,NO and 297 of DL,CO, respectively. Reference equations were established for the outcomes of DL,CO,NO and DL,CO, including the calculated values: Vc, Dm, and the DL,NO/DL,CO ratio.These reference values are based on the largest sample of children to date and may provide a basis for future studies of their clinical utility in differentiating between alterations in the pulmonary circulation and changes in the alveolar membrane in pediatric patients.

Some behavioral aspects of energy descent: How a biophysical psychology might help people transition through the lean times ahead

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Raymond eDe Young

2014-11-01

Full Text Available We may soon face biophysical limits to perpetual growth. Energy supplies may tighten and then begin a long slow descent while defensive expenditures rise to address problems caused by past resource consumption. The outcome may be significant changes in daily routines at the individual and community level. It is difficult to know when this scenario might begin to unfold but it clearly would constitute a new behavioral context, one that the behavioral sciences least attends to. Even if one posits a less dramatic scenario, people may still need to make many urgent and perhaps unsettling transitions. And while a robust response would be needed, it is not at all clear what should be the details of that response. Since it is likely that no single response will fix things everywhere, for all people or for all time it would be useful to conduct many social experiments. Indeed, a culture of small experiments should be fostered which, at the individual and small group level, can be described as behavioral entrepreneurship. This may have begun, hidden in plain sight, but more social experiments are needed. To be of help, it may be useful to both package behavioral insights in a way that is practitioner-oriented and grounded in biophysical trends and to propose a few key questions that need attention. This paper begins the process of developing a biophysical psychology, incomplete as it is at this early stage.

Some behavioral aspects of energy descent: how a biophysical psychology might help people transition through the lean times ahead.

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De Young, Raymond

2014-01-01

We may soon face biophysical limits to perpetual growth. Energy supplies may tighten and then begin a long slow descent while defensive expenditures rise to address problems caused by past resource consumption. The outcome may be significant changes in daily routines at the individual and community level. It is difficult to know when this scenario might begin to unfold but it clearly would constitute a new behavioral context, one that the behavioral sciences least attends to. Even if one posits a less dramatic scenario, people may still need to make many urgent and perhaps unsettling transitions. And while a robust response would be needed, it is not at all clear what should be the details of that response. Since it is likely that no single response will fix things everywhere, for all people or for all time, it would be useful to conduct many social experiments. Indeed, a culture of small experiments should be fostered which, at the individual and small group level, can be described as behavioral entrepreneurship. This may have begun, hidden in plain sight, but more social experiments are needed. To be of help, it may be useful to both package behavioral insights in a way that is practitioner-oriented and grounded in biophysical trends and to propose a few key questions that need attention. This paper begins the process of developing a biophysical psychology, incomplete as it is at this early stage.

Some behavioral aspects of energy descent: how a biophysical psychology might help people transition through the lean times ahead

Science.gov (United States)

De Young, Raymond

2014-01-01

We may soon face biophysical limits to perpetual growth. Energy supplies may tighten and then begin a long slow descent while defensive expenditures rise to address problems caused by past resource consumption. The outcome may be significant changes in daily routines at the individual and community level. It is difficult to know when this scenario might begin to unfold but it clearly would constitute a new behavioral context, one that the behavioral sciences least attends to. Even if one posits a less dramatic scenario, people may still need to make many urgent and perhaps unsettling transitions. And while a robust response would be needed, it is not at all clear what should be the details of that response. Since it is likely that no single response will fix things everywhere, for all people or for all time, it would be useful to conduct many social experiments. Indeed, a culture of small experiments should be fostered which, at the individual and small group level, can be described as behavioral entrepreneurship. This may have begun, hidden in plain sight, but more social experiments are needed. To be of help, it may be useful to both package behavioral insights in a way that is practitioner-oriented and grounded in biophysical trends and to propose a few key questions that need attention. This paper begins the process of developing a biophysical psychology, incomplete as it is at this early stage. PMID:25404926

Technical Note: FreeCT_ICD: An Open Source Implementation of a Model-Based Iterative Reconstruction Method using Coordinate Descent Optimization for CT Imaging Investigations.

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Hoffman, John M; Noo, Frédéric; Young, Stefano; Hsieh, Scott S; McNitt-Gray, Michael

2018-06-01

To facilitate investigations into the impacts of acquisition and reconstruction parameters on quantitative imaging, radiomics and CAD using CT imaging, we previously released an open source implementation of a conventional weighted filtered backprojection reconstruction called FreeCT_wFBP. Our purpose was to extend that work by providing an open-source implementation of a model-based iterative reconstruction method using coordinate descent optimization, called FreeCT_ICD. Model-based iterative reconstruction offers the potential for substantial radiation dose reduction, but can impose substantial computational processing and storage requirements. FreeCT_ICD is an open source implementation of a model-based iterative reconstruction method that provides a reasonable tradeoff between these requirements. This was accomplished by adapting a previously proposed method that allows the system matrix to be stored with a reasonable memory requirement. The method amounts to describing the attenuation coefficient using rotating slices that follow the helical geometry. In the initially-proposed version, the rotating slices are themselves described using blobs. We have replaced this description by a unique model that relies on tri-linear interpolation together with the principles of Joseph's method. This model offers an improvement in memory requirement while still allowing highly accurate reconstruction for conventional CT geometries. The system matrix is stored column-wise and combined with an iterative coordinate descent (ICD) optimization. The result is FreeCT_ICD, which is a reconstruction program developed on the Linux platform using C++ libraries and the open source GNU GPL v2.0 license. The software is capable of reconstructing raw projection data of helical CT scans. In this work, the software has been described and evaluated by reconstructing datasets exported from a clinical scanner which consisted of an ACR accreditation phantom dataset and a clinical pediatric

Examination of polymorphic glutathione S-transferase (GST) genes, tobacco smoking and prostate cancer risk among Men of African Descent: A case-control study

International Nuclear Information System (INIS)

Lavender, Nicole A; Benford, Marnita L; VanCleave, Tiva T; Brock, Guy N; Kittles, Rick A; Moore, Jason H; Hein, David W; Kidd, La Creis R

2009-01-01

Polymorphisms in glutathione S-transferase (GST) genes may influence response to oxidative stress and modify prostate cancer (PCA) susceptibility. These enzymes generally detoxify endogenous and exogenous agents, but also participate in the activation and inactivation of oxidative metabolites that may contribute to PCA development. Genetic variations within selected GST genes may influence PCA risk following exposure to carcinogen compounds found in cigarette smoke and decreased the ability to detoxify them. Thus, we evaluated the effects of polymorphic GSTs (M1, T1, and P1) alone and combined with cigarette smoking on PCA susceptibility. In order to evaluate the effects of GST polymorphisms in relation to PCA risk, we used TaqMan allelic discrimination assays along with a multi-faceted statistical strategy involving conventional and advanced statistical methodologies (e.g., Multifactor Dimensionality Reduction and Interaction Graphs). Genetic profiles collected from 873 men of African-descent (208 cases and 665 controls) were utilized to systematically evaluate the single and joint modifying effects of GSTM1 and GSTT1 gene deletions, GSTP1 105 Val and cigarette smoking on PCA risk. We observed a moderately significant association between risk among men possessing at least one variant GSTP1 105 Val allele (OR = 1.56; 95%CI = 0.95-2.58; p = 0.049), which was confirmed by MDR permutation testing (p = 0.001). We did not observe any significant single gene effects among GSTM1 (OR = 1.08; 95%CI = 0.65-1.82; p = 0.718) and GSTT1 (OR = 1.15; 95%CI = 0.66-2.02; p = 0.622) on PCA risk among all subjects. Although the GSTM1-GSTP1 pairwise combination was selected as the best two factor LR and MDR models (p = 0.01), assessment of the hierarchical entropy graph suggested that the observed synergistic effect was primarily driven by the GSTP1 Val marker. Notably, the GSTM1-GSTP1 axis did not provide additional information gain when compared to either loci alone based on a

Traditional Gymnastic Exercises for the Pelvic Floor Often Lead to Bladder Neck Descent - a Study Using Perineal Ultrasound.

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Baeßler, Kaven; Junginger, Bärbel

2017-07-01

The aims of physiotherapy in stress incontinent women are to improve pelvic floor function and the continence mechanism including bladder neck support and urethral closure pressure. In Germany, traditional conservative treatment often includes gymnastic exercises with unclear effects on the bladder neck. The aim of this study was to sonographically assess bladder neck movements during selected exercises. Fifteen healthy, continent women without previous vaginal births, who were able to voluntarily contract their pelvic floor muscels performed the shoulder bridge, the abdominal press, tiptoe and the Pilates clam exercises. The first set was performed without any additional instructions. During the second set directions were given to activate the pelvic floor before beginning each exercise and to maintain the contraction throughout the exercise. Bladder neck movement was measured on perineal ultrasound using a validated method with the pubic symphysis as a reference point. The median age of participants was 32 years, median BMI was 23. Eight women were nulliparous and seven had given birth to 1 - 2 children via caesarean section. When exercises were performed without voluntary pelvic floor contraction the bladder neck descended on average between 2.3 and 4.4 mm, and with pelvic floor contraction prior to the exercise only between 0.5 and 2.1 mm (p > 0.05 except for abdominal press p = 0.007). The Pilates clam exercise and toe stand stabilised the bladder neck most effectively. Bladder neck descent often occurs during pelvic floor gymnastic exercises as traditionally performed in Germany, and a voluntary pelvic floor contraction during the exercises does not necessarily prevent this.

Effects of mid-foot contact area ratio on lower body kinetics/kinematics in sagittal plane during stair descent in women.

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Lee, Jinkyu; Hong, Yoon No Gregory; Shin, Choongsoo S

2016-07-01

The mid-foot contact area relative to the total foot contact area can facilitate foot arch structure evaluation. A stair descent motion consistently provides initial fore-foot contact and utilizes the foot arch more actively for energy absorption. The purpose of this study was to compare ankle and knee joint angle, moment, and work in sagittal plane during stair descending between low and high Mid-Foot-Contact-Area (MFCA) ratio group. The twenty-two female subjects were tested and classified into two groups (high MFCA and low MFCA) using their static MFCA ratios. The ground reaction force (GRF) and kinematics of ankle and knee joints were measured while stair descending. During the period between initial contact and the first peak in vertical GRF (early absorption phase), ankle negative work for the low MFCA ratio group was 33% higher than that for the high MFCA ratio group (pcontact and peak dorsiflexion angle (early absorption phase+late absorption phase). The peak ankle dorsiflexion angle was smaller in the low MFCA ratio group (p<0.05). Our results suggest that strategy of energy absorption at the ankle and foot differs depending upon foot arch types classified by MFCA. The low MFCA ratio group seemed to absorb more impact energy using strain in the planar fascia during early absorption phase, whereas the high MFCA ratio group absorbed more impact energy using increased dorsiflexion during late absorption phase. Copyright © 2016 Elsevier B.V. All rights reserved.

Language contact phenomena in the language use of speakers of German descent and the significance of their language attitudes

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Ries, Veronika

2014-03-01

Full Text Available Within the scope of my investigation on language use and language attitudes of People of German Descent from the USSR, I find almost regular different language contact phenomena, such as viel bliny habn=wir gbackt (engl.: 'we cooked lots of pancakes' (cf. Ries 2011. The aim of analysis is to examine both language use with regard to different forms of language contact and the language attitudes of the observed speakers. To be able to analyse both of these aspects and synthesize them, different types of data are required. The research is based on the following two data types: everyday conversations and interviews. In addition, the individual speakers' biography is a key part of the analysis, because it allows one to draw conclusions about language attitudes and use. This qualitative research is based on morpho-syntactic and interactional linguistic analysis of authentic spoken data. The data arise from a corpus compiled and edited by myself. My being a member of the examined group allowed me to build up an authentic corpus. The natural language use is analysed from the perspective of different language contact phenomena and potential functions of language alternations. One central issue is: How do speakers use the languages available to them, German and Russian? Structural characteristics such as code switching and discursive motives for these phenomena are discussed as results, together with the socio-cultural background of the individual speaker. Within the scope of this article I present exemplarily the data and results of one speaker.

Atypical Presentation of Gelsolin Amyloidosis in a Man of African Descent with a Novel Mutation in the Gelsolin Gene.

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Oregel, Karlos Z; Shouse, Geoffrey P; Oster, Cyrus; Martinez, Freddy; Wang, Jun; Rosenzweig, Michael; Deisch, Jeremy K; Chen, Chien-Shing; Nagaraj, Gayathri

2018-03-30

BACKGROUND Gelsolin amyloidosis is a very rare systemic disease presenting with a pathognomonic triad of corneal lattice dystrophy, cutis laxa, and polyneuropathy. The disease is mostly restricted to a Finnish population with known mutations (G654A, G654T) in exon 4 of the gelsolin gene. The mutations lead to errors in protein processing and folding, and ultimately leads to deposition of an amyloidogenic fragment in the extracellular space, causing the symptoms of disease. CASE REPORT We present a case of gelsolin amyloidosis in a male of African descent with an atypical clinical presentation including fevers, skin rash, polyneuropathy, and anemia. Gelsolin amyloidosis was diagnosed based on mass spectrometry of tissue samples. Importantly, a novel mutation in the gelsolin gene (C1375G) in exon 10 was found in this patient. His atypical presentation can possibly be attributed to the presence of a novel mutation in the gelsolin gene as the likely underlying cause of the syndrome. PCR primers were used to amplify the gelsolin gene from genomic DNA. Purified PCR products were then shipped to Eton Biosciences (San Diego, CA) for sequencing. CONCLUSIONS This study carries several important lessons relevant to the practice of medicine. First, the differential diagnosis for multisystem disease presentations should always include amyloidosis. Second, despite what has been uncovered about the molecular biology of disease, there is always more that can be discovered. Finally, further work to verify the link between this mutation and the clinical syndrome is still needed, as are effective treatments for this disease.

Slow angled-descent forepaw grasping (SLAG): an innate behavioral task for identification of individual experimental mice possessing functional vision.

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Gil-Pagés, Macarena; Stiles, Robert J; Parks, Christopher A; Neier, Steven C; Radulovic, Maja; Oliveros, Alfredo; Ferrer, Alejandro; Reed, Brendan K; Wilton, Katelynn M; Schrum, Adam G

2013-08-23

There is significant interest in the generation of improved assays to clearly identify experimental mice possessing functional vision, a property that could qualify mice for inclusion in behavioral and neuroscience studies. Widely employed current methods rely on mouse responses to visual cues in assays of reflexes, depth perception, or cognitive memory. However, commonly assessed mouse reflexes can sometimes be ambiguous in their expression, while depth perception assays are sometimes confounded by variation in anxiety responses and exploratory conduct. Furthermore, in situations where experimental groups vary in their cognitive memory capacity, memory assays may not be ideal for assessing differences in vision. We have optimized a non-invasive behavioral assay that relies on an untrained, innate response to identify individual experimental mice possessing functional vision: slow angled-descent forepaw grasping (SLAG). First, we verified that SLAG performance depends on vision and not olfaction. Next, all members of an age-ranged cohort of 158 C57BL/6 mice (57 wild-type, 101 knockout, age range 44-241 days) were assessed for functional vision using the SLAG test without training or conditioning. Subjecting the population to a second innate behavioral test, Dark Chamber preference, corroborated that the functional vision assessment of SLAG was valid. We propose that the SLAG assay is immediately useful to quickly and clearly identify experimental mice possessing functional vision. SLAG is based on a behavioral readout with a significant innate component with no requirement for training. This will facilitate the selection of mice of known sighted status in vision-dependent experiments that focus on other types of behavior, neuroscience, and/or cognitive memory.

ADRB2 gene variants, dual-energy x-ray absorptiometry body composition, and hypertension in Tobago men of African descent.

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Beason, Tracey Samantha; Bunker, Clareann H; Zmuda, Joseph M; Wilson, John W; Patrick, Alan L; Wheeler, Victor W; Weissfeld, Joel L

2011-05-01

Classic tissue effects of β(2)-adrenergic receptor activation include skeletal muscle glycogenolysis and vascular smooth muscle relaxation, factors relevant to obesity and hypertension, respectively. In a population-based study, we examined 2 common amino acid substitutions in the β(2)-adrenergic receptor gene (ADRB2) in relation to body composition and blood pressure. A cross-sectional analysis of 1893 African-descent men living in Tobago and participating in a prostate cancer screening study was performed. Body mass index, waist circumference, blood pressure, dual-energy x-ray absorptiometry body composition, and ADRB2 (Arg16Gly; Gln27Glu) genotype were determined. Twenty-six percent were obese (body mass index ≥30 kg/m(2)), and 50% were hypertensive. ADRB2 Arg16Gly and Gln27Glu alleles were in linkage disequilibrium (D' = 0.96, r(2) = 0.15). ADRB2 16Gly-containing and 27Glu-containing genotypes were equally frequent in low, medium, and high tertiles of percentage of body fat mass (16Gly-containing genotypes: 73.4%, 74.4%, and 74.5%, P(trend) = .66; 27Glu-containing genotypes: 27.6%, 23.8%, and 25.4%, P(trend) = .39) and in normal blood pressure, prehypertensive, and hypertensive men (16Gly-containing genotypes: 73.4%, 72.8%, and 74.4%, P(trend) = .61; 27Glu-containing genotypes: 25.6%, 24.1%, and 26.7%, P(trend) = .50). In a high-obesity and high-hypertension risk population with ancestry in common with African Americans, genetic variation defined by 2 common ADRB2 amino acid substitutions was not associated with body composition or hypertension. Copyright © 2011 Elsevier Inc. All rights reserved.

Identity by descent fine mapping of familial adult myoclonus epilepsy (FAME) to 2p11.2-2q11.2.

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Henden, Lyndal; Freytag, Saskia; Afawi, Zaid; Baldassari, Sara; Berkovic, Samuel F; Bisulli, Francesca; Canafoglia, Laura; Casari, Giorgio; Crompton, Douglas Ewan; Depienne, Christel; Gecz, Jozef; Guerrini, Renzo; Helbig, Ingo; Hirsch, Edouard; Keren, Boris; Klein, Karl Martin; Labauge, Pierre; LeGuern, Eric; Licchetta, Laura; Mei, Davide; Nava, Caroline; Pippucci, Tommaso; Rudolf, Gabrielle; Scheffer, Ingrid Eileen; Striano, Pasquale; Tinuper, Paolo; Zara, Federico; Corbett, Mark; Bahlo, Melanie

2016-10-01

Familial adult myoclonus epilepsy (FAME) is a rare autosomal dominant disorder characterized by adult onset, involuntary muscle jerks, cortical myoclonus and occasional seizures. FAME is genetically heterogeneous with more than 70 families reported worldwide and five potential disease loci. The efforts to identify potential causal variants have been unsuccessful in all but three families. To date, linkage analysis has been the main approach to find and narrow FAME critical regions. We propose an alternative method, pedigree free identity-by-descent (IBD) mapping, that infers regions of the genome between individuals that have been inherited from a common ancestor. IBD mapping provides an alternative to linkage analysis in the presence of allelic and locus heterogeneity by detecting clusters of individuals who share a common allele. Succeeding IBD mapping, gene prioritization based on gene co-expression analysis can be used to identify the most promising candidate genes. We performed an IBD analysis using high-density single nucleotide polymorphism (SNP) array data followed by gene prioritization on a FAME cohort of ten European families and one Australian/New Zealander family; eight of which had known disease loci. By identifying IBD regions common to multiple families, we were able to narrow the FAME2 locus to a 9.78 megabase interval within 2p11.2-q11.2. We provide additional evidence of a founder effect in four Italian families and allelic heterogeneity with at least four distinct founders responsible for FAME at the FAME2 locus. In addition, we suggest candidate disease genes using gene prioritization based on gene co-expression analysis.

The 5-HTTLPR polymorphism moderates the effect of stressful life events on drinking behavior in college students of African descent.

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Kranzler, Henry R; Scott, Denise; Tennen, Howard; Feinn, Richard; Williams, Carla; Armeli, Stephen; Taylor, Robert E; Briggs-Gowan, Margaret J; Covault, Jonathan

2012-07-01

Covault et al. [Covault et al. (2007); Biol Psychiatry 61(5): 609-616] reported that the common functional polymorphism, 5-HTTLPR, in the serotonin transporter gene moderated the association between past-year stressful events and daily reports of drinking in a sample of European-American (EA) college students. We examined this effect in college students of African descent. Students recruited at a Historically Black University (n = 564) completed web-based measures of past-year stressful life experiences and daily reports of drinking and heavy drinking over a 30-day period. Participants were genotyped for the tri-allelic 5-HTTLPR polymorphism and dichotomized as low-activity S' allele carriers or high-activity L' homozygotes. Generalized linear models were used to examine the effects of life stress, genotype, and their interaction on the two drinking measures. In students who completed 15 or more daily surveys (n = 393), there was a significant interaction of past-year stressful events, 5-HTTLPR genotype, and gender on the number of drinking days (P = 0.002). Similar findings were obtained in relation to heavy drinking days (P = 0.007). Men showed a main effect of past-year stressful events on both drinking outcomes (P's life stressors on the frequency of drinking and heavy drinking days (P's stressful events were associated with more frequent drinking and heavy drinking, an effect that was moderated by the 5-HTTLPR polymorphism. However, in contrast to the findings in EA students, in the current sample, 5-HTTLPR moderated the association only among women. Copyright © 2012 Wiley Periodicals, Inc.

Application of a Gradient Descent Continuous Actor-Critic Algorithm for Double-Side Day-Ahead Electricity Market Modeling

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Huiru Zhao

2016-09-01

Full Text Available An important goal of China’s electric power system reform is to create a double-side day-ahead wholesale electricity market in the future, where the suppliers (represented by GenCOs and demanders (represented by DisCOs compete simultaneously with each other in one market. Therefore, modeling and simulating the dynamic bidding process and the equilibrium in the double-side day-ahead electricity market scientifically is not only important to some developed countries, but also to China to provide a bidding decision-making tool to help GenCOs and DisCOs obtain more profits in market competition. Meanwhile, it can also provide an economic analysis tool to help government officials design the proper market mechanisms and policies. The traditional dynamic game model and table-based reinforcement learning algorithm have already been employed in the day-ahead electricity market modeling. However, those models are based on some assumptions, such as taking the probability distribution function of market clearing price (MCP and each rival’s bidding strategy as common knowledge (in dynamic game market models, and assuming the discrete state and action sets of every agent (in table-based reinforcement learning market models, which are no longer applicable in a realistic situation. In this paper, a modified reinforcement learning method, called gradient descent continuous Actor-Critic (GDCAC algorithm was employed in the double-side day-ahead electricity market modeling and simulation. This algorithm can not only get rid of the abovementioned unrealistic assumptions, but also cope with the Markov decision-making process with continuous state and action sets just like the real electricity market. Meanwhile, the time complexity of our proposed model is only O(n. The simulation result of employing the proposed model in the double-side day-ahead electricity market shows the superiority of our approach in terms of participant’s profit or social welfare

A chromosome 10 variant with a 12 Mb inversion [inv(10)(q11.22q21.1)] identical by descent and frequent in the Swedish population.

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Entesarian, Miriam; Carlsson, Birgit; Mansouri, Mahmoud Reza; Stattin, Eva-Lena; Holmberg, Eva; Golovleva, Irina; Stefansson, Hreinn; Klar, Joakim; Dahl, Niklas

2009-03-01

We identified a paracentric inversion of chromosome 10 [inv(10)(q11.22q21.1)] in 0.20% of Swedish individuals (15/7,439) referred for cytogenetic analysis. A retrospective analysis of 8,896 karyotypes from amniocenteses in Sweden revealed a carrier frequency of 0.079% (7/8,896) for the inversion. Cloning and detailed analysis of the inversion breakpoint regions show enrichment for interspersed repeat elements and AT-stretches. The centromeric breakpoint coincides with that of a predicted inversion from HapMap data, which suggests that this region is involved in several chromosome 10 variants. No known gene or predicted transcript are disrupted by the inversion which spans approximately 12 Mb. Carriers from four non-related Swedish families have identical inversion breakpoints and haplotype analysis confirmed that the rearrangement is identical by descent. Diagnosis was retrieved in 6 out of the 15 carriers referred for cytogenetic analysis. No consistent phenotype was found to be associated with the inversion. Our study demonstrates that the inv(10)(q11.22q21.1) is a rare and inherited chromosome variant with a broad geographical distribution in Sweden. 2009 Wiley-Liss, Inc.

Breast cancer genetic counseling among Dutch patients from Turkish and Moroccan descent: participation determinants and perspectives of patients and healthcare professionals.

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Baars, J E; van Dulmen, A M; Velthuizen, M E; van Riel, E; Ausems, M G E M

2017-04-01

Lower participation rates in cancer genetic counseling are observed among different ethnic minorities. The goal of our study is to gain insight into determinants of Turkish and Moroccan patients' participation in breast cancer genetic counseling and DNA testing, from the point of view of healthcare professionals and patients. Questionnaire-based telephone interviews about awareness, perceptions, and reasons for (non-) participation in cancer genetic counseling were conducted with 78 Dutch breast cancer patients from Turkish and Moroccan descent. The interviews were held in Arabic, Berber, Turkish, or Dutch by bilingual research assistants. Additionally, 14 breast cancer patients participated in one of two focus group meetings, and two focus groups were held with 11 healthcare professionals. SPSS and QSR Nvivo were used to examine the quantitative and qualitative data, respectively. Half of the total group of patients (N = 78) and 79% of patients eligible for genetic counseling and testing (N = 33) were aware of the possibility of genetic counseling. The most important determinants for nonparticipation in genetic counseling were experienced difficulties in patient-doctor communication, cultural factors (e.g., social norms), limited health literacy, limited knowledge of the family cancer history, and anxiety about cancer. Religious beliefs and knowing personal and family members' breast cancer risks were motives to obtain genetic counseling. Despite the fact that our study showed that Moroccan and Turkish women reported several personal motives to obtain genetic counseling and testing (GCT), patients and healthcare professionals experience significant language and health literacy difficulties, which make it harder to fully access health care such as genetic counseling and testing.

Meteorological Predictions in Support of the Mars Science Laboratory Entry, Descent and Landing

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Rothchild, A.; Rafkin, S. C.; Pielke, R. A., Sr.

2010-12-01

The Mars Science Laboratory (MSL) entry, descent, and landing (EDL) system employs a standard parachute strategy followed by a new sky crane concept where the rover is lowered to the ground via a tether from a hovering entry vehicle. As with previous missions, EDL system performance is sensitive to atmospheric conditions. While some observations characterizing the mean, large-scale atmospheric temperature and density data are available, there is effectively no information on the atmospheric conditions and variability at the scale that directly affects the spacecraft. In order to evaluate EDL system performance and to assess landing hazards and risk, it is necessary to simulate the atmosphere with a model that provides data at the appropriate spatial and temporal scales. Models also permit the study of the impact of the highly variable atmospheric dust loading on temperature, density and winds. There are four potential MSL landing sites: Mawrth Valle (22.3 N, 16.5W) , Gale Crater (5.4S, 137.7E), Holden Crater (26.1S, 34W), and Eberswalde Crater (24S, 33W). The final selection of the landing site will balance potential science return against landing and operational risk. Atmospheric modeling studies conducted with the Mars Regional Atmospheric Modeling System (MRAMS) is an integral part of the selection process. At each of the landing sites, a variety of simulations are conducted. The first type of simulations provide baseline predictions under nominal atmospheric dust loading conditions within the landing site window of ~Ls 150-170. The second type of simulation explores situations with moderate and high global atmospheric dust loading. The final type of simulation investigates the impact of local dust disturbances at the landing site. Mean and perturbation fields from each type of simulation at each of the potential landing sites are presented in comparison with the engineering performance limitations for the MSL EDL system. Within the lowest scale height, winds

Interactions of dietary whole-grain intake with fasting glucose- and insulin-related genetic loci in individuals of European descent: a meta-analysis of 14 cohort studies.

Science.gov (United States)

Nettleton, Jennifer A; McKeown, Nicola M; Kanoni, Stavroula; Lemaitre, Rozenn N; Hivert, Marie-France; Ngwa, Julius; van Rooij, Frank J A; Sonestedt, Emily; Wojczynski, Mary K; Ye, Zheng; Tanaka, Tosh; Garcia, Melissa; Anderson, Jennifer S; Follis, Jack L; Djousse, Luc; Mukamal, Kenneth; Papoutsakis, Constantina; Mozaffarian, Dariush; Zillikens, M Carola; Bandinelli, Stefania; Bennett, Amanda J; Borecki, Ingrid B; Feitosa, Mary F; Ferrucci, Luigi; Forouhi, Nita G; Groves, Christopher J; Hallmans, Goran; Harris, Tamara; Hofman, Albert; Houston, Denise K; Hu, Frank B; Johansson, Ingegerd; Kritchevsky, Stephen B; Langenberg, Claudia; Launer, Lenore; Liu, Yongmei; Loos, Ruth J; Nalls, Michael; Orho-Melander, Marju; Renstrom, Frida; Rice, Kenneth; Riserus, Ulf; Rolandsson, Olov; Rotter, Jerome I; Saylor, Georgia; Sijbrands, Eric J G; Sjogren, Per; Smith, Albert; Steingrímsdóttir, Laufey; Uitterlinden, André G; Wareham, Nicholas J; Prokopenko, Inga; Pankow, James S; van Duijn, Cornelia M; Florez, Jose C; Witteman, Jacqueline C M; Dupuis, Josée; Dedoussis, George V; Ordovas, Jose M; Ingelsson, Erik; Cupples, L Adrienne; Siscovick, David S; Franks, Paul W; Meigs, James B

2010-12-01

Whole-grain foods are touted for multiple health benefits, including enhancing insulin sensitivity and reducing type 2 diabetes risk. Recent genome-wide association studies (GWAS) have identified several single nucleotide polymorphisms (SNPs) associated with fasting glucose and insulin concentrations in individuals free of diabetes. We tested the hypothesis that whole-grain food intake and genetic variation interact to influence concentrations of fasting glucose and insulin. Via meta-analysis of data from 14 cohorts comprising ∼ 48,000 participants of European descent, we studied interactions of whole-grain intake with loci previously associated in GWAS with fasting glucose (16 loci) and/or insulin (2 loci) concentrations. For tests of interaction, we considered a P value fasting glucose and insulin concentrations independent of demographics, other dietary and lifestyle factors, and BMI (β [95% CI] per 1-serving-greater whole-grain intake: -0.009 mmol/l glucose [-0.013 to -0.005], P fasting insulin (P = 0.006), where greater whole-grain intake was associated with a smaller reduction in fasting insulin concentrations in those with the insulin-raising allele. Our results support the favorable association of whole-grain intake with fasting glucose and insulin and suggest a potential interaction between variation in GCKR and whole-grain intake in influencing fasting insulin concentrations.

Continuous Descent Approach (CDA) compared to regular descent procedures : Less annoying?

NARCIS (Netherlands)

White, K.; Arntzen, M.; Bronkhorst, A.; Meeter, M.

2014-01-01

Annoyance reactions to different types of landing procedures were addressed in a controlled laboratory setting using a Virtual Community Noise Simulator (VCNS) with a head mounted display.Participants, standing on a virtual countryside road, experienced four types of descentflyovers by an A330

[Ethnic differences in forensic psychiatry: an exploratory study at a Dutch forensic psychiatric centre].

Science.gov (United States)

van der Stoep, T

Compared to the percentage of ethnic minorities in the general population, ethnic minorities are overrepresented in forensic psychiatry. If these minorities are to be treated successfully, we need to know more about this group. So far, however, little is known about the differences between mental disorders and types of offences associated with patients of non-Dutch descent and those associated with patients of Dutch descent. AIM: To take the first steps to obtain the information we need in order to provide customised care for patients of non-Dutch descent. METHOD: It proved possible to identify differences between patients of Dutch and non-Dutch descent with regard to treatment, diagnosis and offences committed within a group of patients who were admitted to the forensic psychiatric centre Oostvaarderskliniek during the period 2001 - 2014. RESULTS: The treatment of patients of non-Dutch descent lasted longer than the treatment of patients of Dutch descent (8.5 year versus 6.6 year). Furthermore, patients from ethnic minority groups were diagnosed more often with schizophrenia (49.1% versus 21.4%), but less often with pervasive developmental disorders or sexual disorders. Patients of non-Dutch descent were more often convicted for sexual crimes where the victim was aged 16 years or older, whereas patients of Dutch descent were convicted of sexual crimes where the victim was under 16. CONCLUSION: There are differences between patients of Dutch and non-Dutch descent with regard to treatment duration, diagnosis and offences they commit. Future research needs to investigate whether these results are representative for the entire field of forensic psychiatry and to discover the reasons for these differences.

Propulsion Aspects of Unmanned and Manned Lunar Landings

Directory of Open Access Journals (Sweden)

D. S. CARTON

1963-06-01

Full Text Available Direct vertical descent and descent from an intermediate
lunar parking orbit are discussed. The difference in philosophy between
langing a payload of instruments and of humans is considered in some
detail. The " human return to eartli " problem is separated from the
" mission success-failure " criteria.
Some anticipated performances are given in terms of payload ratio
for various propulsion-cehicle vcaling constants for botli forms of descent.
Manned descent from parking orbit is discussed with respect to the
general problem of maximising the probability of human return. .Minimum
impulse, high safety and long low approaches are mentioned. In conclusion
the problem of abort during the final powered descent is considered for
fixed and variable geometry vehicles.

Toward a Caribbean psychology: an African-centered approach.

Science.gov (United States)

Sutherland, Marcia Elizabeth

2011-01-01

Although the Americas and Caribbean region are purported to comprise different ethnic groups, this article’s focus is on people of African descent, who represent the largest ethnic group in many countries. The emphasis on people of African descent is related to their family structure, ethnic identity, cultural, psychohistorical, and contemporary psychosocial realities. This article discusses the limitations of Western psychology for theory, research, and applied work on people of African descent in the Americas and Caribbean region. In view of the adaptations that some people of African descent have made to slavery, colonialism, and more contemporary forms of cultural intrusions, it is argued that when necessary, notwithstanding Western psychology’s limitations, Caribbean psychologists should reconstruct mainstream psychology to address the psychological needs of these Caribbean people. The relationship between theory and psychological interventions for the optimal development of people of African descent is emphasized throughout this article. In this regard, the African-centered and constructionist viewpoint is argued to be of utility in addressing the psychological growth and development of people of African descent living in the Americas and Caribbean region.

The Descent of the Serpent: Using a Successful Ancient Solar Observatories Webcast from Chichen Itza to Highlight Space Weather Research

Science.gov (United States)

Hawkins, I.; Higdon, R.; Cline, T.

2006-12-01

Over the past seven years, NASA's Sun-Earth Connection Education Forum has sponsored and coordinated education and public outreach events to highlight NASA's heliophysics research and discoveries. Our strategy involves using celestial events, such as total solar eclipses and the Transit of Venus, as well as Sun-Earth Day during the March Equinox, to engage K-12 schools and the general public in space science activities, demonstrations, and interactions with space scientists. In collaboration with partners that include the Exploratorium and other museums, Ideum, NASA TV, NASA heliophysics missions, and others, we produce webcasts, other multi-media, and print resources for use by school and informal educators nation-wide and internationally. We provide training and professional development to K-12 educators, museum personnel, amateur astronomers, Girl Scout leaders, etc., so they can implement their own outreach programs taking advantage of our resources. A coordinated approach promotes multiple programs occurring each year under a common theme. As part of an Ancient Observatories theme in 2005, we have successfully featured solar alignments with ancient structures made by indigenous cultures that mark the equinoxes and/or solstices in cultural and historical parks in the Americas. In partnership with the Exploratorium, we produced broadcast-quality and webcast programming during the March equinox that shared heliophysics within a broad cultural context with formal and informal education audiences internationally. The program: "Descent of the Serpent" featured the light and shadow effect at sunset that takes place during the spring equinox at the Pyramid of El Castillo, in Chichén Itzá (México). This program made unique and authentic cultural connections to the knowledge of solar astronomy of the Maya, the living Mayan culture of today, and the importance of the Sun across the ages. We involved Sun-Earth Connection scientists, their missions, and research

The Descent of Math

OpenAIRE

Walker, Sara Imari

2015-01-01

A perplexing problem in understanding physical reality is why the universe seems comprehensible, and correspondingly why there should exist physical systems capable of comprehending it. In this essay I explore the possibility that rather than being an odd coincidence arising due to our strange position as passive (and even more strangely, conscious) observers in the cosmos, these two problems might be related and could be explainable in terms of fundamental physics. The perspective presented ...

Hymenobacter roseosalivarius gen. nov., sp. nov. from continental Antartica soils and sandstone: bacteria of the Cytophaga/Flavobacterium/Bacteroides line of phylogenetic descent.

Science.gov (United States)

Hirsch, P; Ludwig, W; Hethke, C; Sittig, M; Hoffmann, B; Gallikowski, C A

1998-08-01

Aseptically collected sandstone and soil samples from the antarctic Dry Valleys were inoculated into oligotrophic media and incubated under low light intensities. A total of 41 Gram-negative isolates were obtained with reddish colonies spreading on agar. A sandstone isolate and four soil strains were characterized further. They were nearly identical in morphological, physiological, biochemical and chemotaxonomic properties. They produced large amounts of extracellular polymer and utilized for growth: glucose, saccharose, mannitol, sorbitol, L-aspartate, malate and acetate, but not D-ribose, adonitol, DL-alanine, glutamate, glycolate, lactate or succinate. All strains hydrolyzed gelatin, starch, casein, xylan, Tweens 80 or 60 and dead or living yeast cells, but not cellulose or pectin. Nitrate was not reduced, ethanol was not oxidized and acid was not produced from maltose, mannitol or dulcitol. Ammonia was not produced from peptone. They were strictly aerobic. Major fatty acids were n 16:1 d 9, n 16:1 d 11, n 17:1 d 11, and i 15:0. The strains contained the quinone MK-7 and phosphatidylethanolamine as the main phospholipid. The base ratio ranged from 55 to 61 mol% G+C. A 16S rRNA sequence analysis of strains AA-688 and AA-718 showed these to be identical and to represent a special phylogenetic group within the Cytophaga/Flavobacterium/Bacteroides major line of descent. Three soil strains labeled "Taxeobacter" Txc1, Txg1, and Txo1 (Reichenbach, 1992) belonged to the same group but had lower sequence similarities (<95%). Some of their characteristics were different from those of the antarctic strains: the utilization of C-compounds, hydrolysis of polymers, temperature tolerances, major fatty acids and base ratios. Txc1 and Txg1 may later have to be considered as members of this group, possibly on the species level, while Txo1 could represent a different related genus. It is concluded that the five antarctic strains represent a new genus and species for which the name

The Spillover of US Immigration Policy on Citizens and Permanent Residents of Mexican Descent: How Internalizing ‘Illegality’ Impacts Public Health in the Borderlands

Directory of Open Access Journals (Sweden)

Samantha eSabo

2015-06-01

Full Text Available Background: The militarization of the U.S.-Mexico border region exacerbates the process of ‘Othering’ Latino immigrants—as illegal aliens. The internalization of ‘illegality’ can manifest as a sense of undeservingness of legal protection in the population and be detrimental on a biopsychological level. Objective: We explore the impacts of ‘illegality’ among a population of US citizen and permanent resident farmworkers of Mexican descent. We do so through the lens of immigration enforcement-related stress and the ability to file formal complaints of discrimination and mistreatment perpetrated by local immigration enforcement agents, including local police authorized to enforce immigration law. Methods: Drawing from cross-sectional data gathered through the National Institute of Occupation Safety and Health, Challenges to Farmworker Health at the US-Mexico Border study, a community-based participatory research project conducted at the Arizona-Sonora border, we compared Arizona resident farmworkers (N=349 to Mexico-based farmworkers (N=140 or Transnational farmworkers who cross the US-Mexico border daily or weekly to work in US agriculture. Results: Both samples of farmworkers experience significant levels of stress in anticipation of encounters with immigration officials. Fear was cited as the greatest factor preventing individuals from reporting immigration abuses. The groups varied slightly in the relative weight attributed to different types of fear. Conclusion: The militarization of the border has consequences for individuals who are not the target of immigration enforcement. These spillover effects cause harm to farmworkers in multiple ways. Multi institutional and community-centered systems for reporting immigration related victimization is required. Applied participatory research with affected communities can mitigate the public health effects of state-sponsored immigration discrimination and violence among US citizen and

Powered Flight Design and Reconstructed Performance Summary for the Mars Science Laboratory Mission

Science.gov (United States)

Sell, Steven; Chen, Allen; Davis, Jody; San Martin, Miguel; Serricchio, Frederick; Singh, Gurkirpal

2013-01-01

The Powered Flight segment of Mars Science Laboratory's (MSL) Entry, Descent, and Landing (EDL) system extends from backshell separation through landing. This segment is responsible for removing the final 0.1% of the kinetic energy dissipated during EDL and culminating with the successful touchdown of the rover on the surface of Mars. Many challenges exist in the Powered Flight segment: extraction of Powered Descent Vehicle from the backshell, performing a 300m divert maneuver to avoid the backshell and parachute, slowing the descent from 85 m/s to 0.75 m/s and successfully lowering the rover on a 7.5m bridle beneath the rocket-powered Descent Stage and gently placing it on the surface using the Sky Crane Maneuver. Finally, the nearly-spent Descent Stage must execute a Flyaway maneuver to ensure surface impact a safe distance from the Rover. This paper provides an overview of the powered flight design, key features, and event timeline. It also summarizes Curiosity's as flown performance on the night of August 5th as reconstructed by the flight team.

14 CFR 431.35 - Acceptable reusable launch vehicle mission risk.

Science.gov (United States)

2010-01-01

... applicable, and reentry or descent flight, and concludes upon landing on Earth of the RLV. (b) Acceptable... reentry or descent of the vehicle through landing, including its three-sigma dispersion. [Docket No. FAA...

Sandhoff Disease

Science.gov (United States)

... which had been particularly high in people of Eastern European and Ashkenazi Jewish descent, but Sandhoff disease ... which had been particularly high in people of Eastern European and Ashkenazi Jewish descent, but Sandhoff disease ...

SU-F-I-49: Vendor-Independent, Model-Based Iterative Reconstruction On a Rotating Grid with Coordinate-Descent Optimization for CT Imaging Investigations

International Nuclear Information System (INIS)

Young, S; Hoffman, J; McNitt-Gray, M; Noo, F

2016-01-01

Purpose: Iterative reconstruction methods show promise for improving image quality and lowering the dose in helical CT. We aim to develop a novel model-based reconstruction method that offers potential for dose reduction with reasonable computation speed and storage requirements for vendor-independent reconstruction from clinical data on a normal desktop computer. Methods: In 2012, Xu proposed reconstructing on rotating slices to exploit helical symmetry and reduce the storage requirements for the CT system matrix. Inspired by this concept, we have developed a novel reconstruction method incorporating the stored-system-matrix approach together with iterative coordinate-descent (ICD) optimization. A penalized-least-squares objective function with a quadratic penalty term is solved analytically voxel-by-voxel, sequentially iterating along the axial direction first, followed by the transaxial direction. 8 in-plane (transaxial) neighbors are used for the ICD algorithm. The forward problem is modeled via a unique approach that combines the principle of Joseph’s method with trilinear B-spline interpolation to enable accurate reconstruction with low storage requirements. Iterations are accelerated with multi-CPU OpenMP libraries. For preliminary evaluations, we reconstructed (1) a simulated 3D ellipse phantom and (2) an ACR accreditation phantom dataset exported from a clinical scanner (Definition AS, Siemens Healthcare). Image quality was evaluated in the resolution module. Results: Image quality was excellent for the ellipse phantom. For the ACR phantom, image quality was comparable to clinical reconstructions and reconstructions using open-source FreeCT-wFBP software. Also, we did not observe any deleterious impact associated with the utilization of rotating slices. The system matrix storage requirement was only 4.5GB, and reconstruction time was 50 seconds per iteration. Conclusion: Our reconstruction method shows potential for furthering research in low

SU-F-I-49: Vendor-Independent, Model-Based Iterative Reconstruction On a Rotating Grid with Coordinate-Descent Optimization for CT Imaging Investigations

Energy Technology Data Exchange (ETDEWEB)

Young, S; Hoffman, J; McNitt-Gray, M [UCLA School of Medicine, Los Angeles, CA (United States); Noo, F [University of Utah, Salt Lake City, UT (United States)

2016-06-15

Purpose: Iterative reconstruction methods show promise for improving image quality and lowering the dose in helical CT. We aim to develop a novel model-based reconstruction method that offers potential for dose reduction with reasonable computation speed and storage requirements for vendor-independent reconstruction from clinical data on a normal desktop computer. Methods: In 2012, Xu proposed reconstructing on rotating slices to exploit helical symmetry and reduce the storage requirements for the CT system matrix. Inspired by this concept, we have developed a novel reconstruction method incorporating the stored-system-matrix approach together with iterative coordinate-descent (ICD) optimization. A penalized-least-squares objective function with a quadratic penalty term is solved analytically voxel-by-voxel, sequentially iterating along the axial direction first, followed by the transaxial direction. 8 in-plane (transaxial) neighbors are used for the ICD algorithm. The forward problem is modeled via a unique approach that combines the principle of Joseph’s method with trilinear B-spline interpolation to enable accurate reconstruction with low storage requirements. Iterations are accelerated with multi-CPU OpenMP libraries. For preliminary evaluations, we reconstructed (1) a simulated 3D ellipse phantom and (2) an ACR accreditation phantom dataset exported from a clinical scanner (Definition AS, Siemens Healthcare). Image quality was evaluated in the resolution module. Results: Image quality was excellent for the ellipse phantom. For the ACR phantom, image quality was comparable to clinical reconstructions and reconstructions using open-source FreeCT-wFBP software. Also, we did not observe any deleterious impact associated with the utilization of rotating slices. The system matrix storage requirement was only 4.5GB, and reconstruction time was 50 seconds per iteration. Conclusion: Our reconstruction method shows potential for furthering research in low

Cough urethrocystography: The best radiological evaluation of female stress urinary incontinence?

International Nuclear Information System (INIS)

Varpula, M.; Maekinen, J.; Kiilholma, P.

1989-01-01

Urethrocystography and simultaneous urethrocystometry were performed on 40 women with primary urinary incontinence. The posterior urethrovesical angle, inclination angle, urethropelvic angle, and an orifice descent angle, not earlier described, were measured on radiographs obtained at rest, during coughing and during straining. The orifice descent angle was used to describe the descent of the internal urethral orifice in the cough radiographs, and was the only measurement that provided a significant correlation with urethrocystometry. The other angles measured, and radiographs obtained at rest or during straining were not useful in the evaluation of female stress urinary incontinence. The authors conclude that the best imaging method for the evaluation of female stress urinary incontinence is urethrocystography employing a single lateral view taken during coughing, with measurement of the orifice descent angle. (orig.)

Autoimmunity predominates in a large South African cohort with Addison's disease of mainly European descent despite long-standing disease and is associated with HLA DQB*0201.

Science.gov (United States)

Ross, Ian; Boulle, Andrew; Soule, Steven; Levitt, Naomi; Pirie, Fraser; Karlsson, Anders; Mienie, Japie; Yang, Ping; Wang, Hongjie; She, Jin-Xiong; Winter, William; Schatz, Desmond

2010-09-01

We sought to determine whether autoimmunity is the predominant cause of Addison's disease in South Africa and whether human leucocyte antigen (HLA) DQ association exists. We compiled a national registry of patients from primary care, referral centres and private practices. A total of 144 patients, 94 of European descent, 34 Mixed Ancestry, 5 Asian and 11 Black Africans (mean age 45.9 years, range 2.7-88 years; mean duration of disease 13.1 years, range 0-50 years) and controls were matched for gender and ethnicity. All potential causes were investigated. Fifty one per cent of cases (74 patients) were autoimmune in aetiology. Either 21-hydroxylase autoantibodies (72 patients, 50% of entire patient group) or adrenocortical autoantibodies (35 patients, 24%) were present, while 23% of patients had both. None of the Asian (n = 5) or Black (n = 11) patients had evidence of autoimmune disease. Overall 8% of patients had tuberculosis, 4% adrenoleucodystrophy, 1% adrenocorticotrophic hormone resistance syndrome and 6% X-linked adrenal hypoplasia. In those with autoimmune disease primary hypothyroidism (47%), premature ovarian failure (8%) and type 1 diabetes (7%) were the most prevalent accompanying autoimmune conditions. HLA DQB1*0201 alleles predominated in the autoimmune group (DQB1*0201: 65%vs 43% of controls P = 0.017) with the *0201/*0302 heterozygous genotype being the most prevalent (28%vs 8%P = 0.02). While autoimmunity accounts for at least half of patients with Addison's disease in South Africa and is associated with HLA DQB1*0201, none of the Black Africans or Asians in this cohort had adrenal autoantibodies. Moreover, 21-hydroxylase autoantibodies were detectable in a higher proportion than adrenocortical autoantibodies, especially in those patients with a long history after disease onset.

Identification of independent association signals and putative functional variants for breast cancer risk through fine-scale mapping of the 12p11 locus

OpenAIRE

Zeng, Chenjie; Guo, Xingyi; Long, Jirong; Kuchenbaecker, Karoline B.; Droit, Arnaud; Michailidou, Kyriaki; Ghoussaini, Maya; Kar, Siddhartha; Freeman, Adam; Hopper, John L.; Milne, Roger L.; Bolla, Manjeet K.; Wang, Qin; Dennis, Joe; Agata, Simona

2016-01-01

Background: Multiple recent genome-wide association studies (GWAS) have identified a single nucleotide polymorphism (SNP), rs10771399, at 12p11 that is associated with breast cancer risk. Method: We performed a fine-scale mapping study of a 700 kb region including 441 genotyped and more than 1300 imputed genetic variants in 48,155 cases and 43,612 controls of European descent, 6269 cases and 6624 controls of East Asian descent and 1116 cases and 932 controls of African descent in the Breast C...

Phylogenetic reconstruction of Bantu kinship challenges Main Sequence Theory of human social evolution.

Science.gov (United States)

Opie, Christopher; Shultz, Susanne; Atkinson, Quentin D; Currie, Thomas; Mace, Ruth

2014-12-09

Kinship provides the fundamental structure of human society: descent determines the inheritance pattern between generations, whereas residence rules govern the location a couple moves to after they marry. In turn, descent and residence patterns determine other key relationships such as alliance, trade, and marriage partners. Hunter-gatherer kinship patterns are viewed as flexible, whereas agricultural societies are thought to have developed much more stable kinship patterns as they expanded during the Holocene. Among the Bantu farmers of sub-Saharan Africa, the ancestral kinship patterns present at the beginning of the expansion are hotly contested, with some arguing for matrilineal and matrilocal patterns, whereas others maintain that any kind of lineality or sex-biased dispersal only emerged much later. Here, we use Bayesian phylogenetic methods to uncover the history of Bantu kinship patterns and trace the interplay between descent and residence systems. The results suggest a number of switches in both descent and residence patterns as Bantu farming spread, but that the first Bantu populations were patrilocal with patrilineal descent. Across the phylogeny, a change in descent triggered a switch away from patrifocal kinship, whereas a change in residence triggered a switch back from matrifocal kinship. These results challenge "Main Sequence Theory," which maintains that changes in residence rules precede change in other social structures. We also indicate the trajectory of kinship change, shedding new light on how this fundamental structure of society developed as farming spread across the globe during the Neolithic.

On Nonconvex Decentralized Gradient Descent

Science.gov (United States)

2016-08-01

and J. Bolte, On the convergence of the proximal algorithm for nonsmooth functions involving analytic features, Math . Program., 116: 5-16, 2009. [2] H...splitting, and regularized Gauss-Seidel methods, Math . Pro- gram., Ser. A, 137: 91-129, 2013. [3] P. Bianchi and J. Jakubowicz, Convergence of a multi-agent...subgradient method under random communication topologies , IEEE J. Sel. Top. Signal Process., 5:754-771, 2011. [11] A. Nedic and A. Ozdaglar, Distributed

Lines of Descent Under Selection

Science.gov (United States)

Baake, Ellen; Wakolbinger, Anton

2017-11-01

We review recent progress on ancestral processes related to mutation-selection models, both in the deterministic and the stochastic setting. We mainly rely on two concepts, namely, the killed ancestral selection graph and the pruned lookdown ancestral selection graph. The killed ancestral selection graph gives a representation of the type of a random individual from a stationary population, based upon the individual's potential ancestry back until the mutations that define the individual's type. The pruned lookdown ancestral selection graph allows one to trace the ancestry of individuals from a stationary distribution back into the distant past, thus leading to the stationary distribution of ancestral types. We illustrate the results by applying them to a prototype model for the error threshold phenomenon.

LHC magnets: the great descent

CERN Multimedia

2005-01-01

A first dipole magnet was delivered to its final location in the LHC tunnel on Monday, 7 March. This achievement coincides with another important milestone in the installation of the future collider, the completion of the delivery of half the dipole magnets.

CLPB Variants Associated with Autosomal-Recessive Mitochondrial Disorder with Cataract, Neutropenia, Epilepsy, and Methylglutaconic Aciduria

DEFF Research Database (Denmark)

Saunders, Carol; Smith, Laurie; Wibrand, Flemming

2015-01-01

of type IV 3-MGA-uria characterized by cataracts, severe psychomotor regression during febrile episodes, epilepsy, neutropenia with frequent infections, and death in early childhood. Four of the individuals were of Greenlandic descent, and one was North American, of Northern European and Asian descent...

Proportional cancer incidence according to selected sites: comparison between residents in the City of S. Paulo, Brazil: Japanese and Brazilian/Portuguese descent Incidência proporcional por câncer: comparação entre residentes no Município de São Paulo de diferentes origens: japonesa e brasileira

Directory of Open Access Journals (Sweden)

José Maria Pacheco de Souza

1991-06-01

Full Text Available The percentual distributions of selected sites of cancer cases according to origin, sex and age are compared. Data were obtained from the Registry of Cancer of S. Paulo (School of Public Health of the University of S. Paulo, Brazil. The reference period for inhabitants of Japanese descent was 1969/78 and for those of Brazilian descent, the period was 1969/75. Standardized Proportionate Incidence Ratios (SPIR with approximate 95% Confidence Intervals (CI were evaluated using age specific Incidence Ratios of S. Paulo, 1973, as standards. The results agree with findings of previous works on mortality, but show different patterns according to origin. The well known fact that some sub-groups of a population may be different from the overall group is once again brought to the fore. Attention should be drawn to the differences detected for stomach, skin and prostate, in males, and for stomach, skin, cervix and uterus in females.São comparadas as distribuições percentuais dos casos de câncer de algumas localizações anatômicas segundo país de nascimento, sexo e idade. Os dados foram coletados no Registro de Câncer de São Paulo da Faculdade de Saúde Pública da USP, referentes aos períodos 1969-1978, para os japoneses, e 1969-1975, para os brasileiros. Razões padronizadas de incidência proporcional e respectivos intervalos com 95% de confiança foram calculados, usando como padrão a incidência proporcional específica por idade de São Paulo, em 1973. Os resultados, consistentes com trabalhos anteriores relativos à mortalidade, mostraram haver possíveis padrões distintos de incidência de câncer em japoneses e brasileiros. Chamou atenção para o fato de que alguns sub-grupos de uma população apresentam comportamentos diferentes e, no presente caso, principalmente quanto à incidência de cânceres de estômago, próstata, pele, em homens, e estômago, pele, colo uterino e útero, em mulheres.

First stage of cosmic expedition Vega: Venus investigations

International Nuclear Information System (INIS)

Balebanov, V.M.; Moroz, V.I.; Mukhin, L.M.

1985-01-01

Main results of the first (Venus) stage of the international complex program ''Venus - Halley'' (''Vega'' for short) are presented. The program is aimed at transporting descent space vehicles to the Venus to explore its atmosphere and surface. Then automatic interplanetary stations (AIS) will be directed to the Halley's comet. In June 1985 the descent space vehicles AIS ''Vega-1'' and ''Vega-2'' have landed softly on the Venus surface, aerostat probes have been launched to the planet atmosphere. The design of the descent space vehicle, structure and chemical composition of the atmosphere, ground composition are briefly outlined

The Case of the Woman Who Did Never Dare to Fly: Headache Attributed to Imbalance Between Intrasinusal and External Air Pressure.

Science.gov (United States)

Mainardi, Federico; Maggioni, Ferdinando; Zanchin, Giorgio

2016-02-01

A new form of headache, Headache attributed to aeroplane travel (AH), has been recognized within the International Classification of Headache Disorders 3 beta (ICHD-3beta). In 8 out of 85 AH cases we identified the coexistence of a headache with identical features of AH, but appearing during the rapid descent by car from a high mountain. Pain began shortly after the rapid descent from a medium altitude of 1920 m above sea level, the maximum peak of intensity developing within a few minutes. All of the patients reported the disappearance of pain within 20 minutes of the rapid descent. We recently observed a 36-year-old woman who experienced recurrent headache attacks that were constantly triggered by rapid descent from high altitude by car. Negatively shaped by this experience, the patient never dared to fly. Headache attacks sharing the same features and occurring in three distinct conditions of pressure variations (aeroplane travel, rapid altitude mountain descent, snorkelling, or scuba diving) have already been reported, although the last two only anecdotally. If confirmed by further case series, they could be gathered together in a unique heading: Headache attributed to imbalance between intrasinusal and external air pressure within the 10th chapter: Headache attributed to disorders of the homoeostasis. © 2016 American Headache Society.

The Fact of Evolution: Implications for Science Education

Science.gov (United States)

Hofmann, James R.; Weber, Bruce H.

Creationists who object to evolution in the science curriculum of public schools often cite Jonathan Well's book Icons of Evolution in their support (Wells2000). In the third chapter of his book Wells claims that neither paleontological nor molecular evidence supports the thesis that the history of life is an evolutionary process of descent from preexisting ancestors. We argue that Wells inappropriately relies upon ambiguities inherent in the term `Darwinian' and the phrase `Darwin'stheory'. Furthermore, he does not accurately distinguish between the overwhelming evidence that supports the thesis of common descent and controversies that pertain to causal mechanisms such as natural selection. We also argue that Wells' attempts to undermine the evidence in support of common descent are flawed and his characterization of the relevant data is misleading. In particular, his assessment of the `Cambrian explosion' does not do justice to the fossil record. Nor do his selective references to debate about molecular and paleontological phylogenies constitute a case against common descent. We conclude that the fossil and molecular evidence is more than sufficient to warrant science educators to present common descent as a well-established scientific fact. We also argue that diagrams depicting the `tree of life' can be pedagogically useful as simplified representations of the history of life.

Values and Communication of Chinese, Filipino, European, Mexican, and Vietnamese American Adolescents with Their Families and Friends.

Science.gov (United States)

Cooper, Catherine R.; And Others

1993-01-01

Total of 393 American college students of Chinese, Filipino, European, Mexican, and Vietnamese descent rated their families' familistic values and their relationship with their families. Mexican, Vietnamese, and Filipino descent students endorsed most strongly values regarding mutual support among siblings, whereas all groups reported more formal…

Accuracy of administratively-assigned ancestry for diverse populations in an electronic medical record-linked biobank.

Directory of Open Access Journals (Sweden)

Jacob B Hall

Full Text Available Recently, the development of biobanks linked to electronic medical records has presented new opportunities for genetic and epidemiological research. Studies based on these resources, however, present unique challenges, including the accurate assignment of individual-level population ancestry. In this work we examine the accuracy of administratively-assigned race in diverse populations by comparing assigned races to genetically-defined ancestry estimates. Using 220 ancestry informative markers, we generated principal components for patients in our dataset, which were used to cluster patients into groups based on genetic ancestry. Consistent with other studies, we find a strong overall agreement (Kappa  = 0.872 between genetic ancestry and assigned race, with higher rates of agreement for African-descent and European-descent assignments, and reduced agreement for Hispanic, East Asian-descent, and South Asian-descent assignments. These results suggest caution when selecting study samples of non-African and non-European backgrounds when administratively-assigned race from biobanks is used.

The importance of identity-by-state information for the accuracy of genomic selection

Directory of Open Access Journals (Sweden)

Luan Tu

2012-08-01

Full Text Available Abstract Background It is commonly assumed that prediction of genome-wide breeding values in genomic selection is achieved by capitalizing on linkage disequilibrium between markers and QTL but also on genetic relationships. Here, we investigated the reliability of predicting genome-wide breeding values based on population-wide linkage disequilibrium information, based on identity-by-descent relationships within the known pedigree, and to what extent linkage disequilibrium information improves predictions based on identity-by-descent genomic relationship information. Methods The study was performed on milk, fat, and protein yield, using genotype data on 35 706 SNP and deregressed proofs of 1086 Italian Brown Swiss bulls. Genome-wide breeding values were predicted using a genomic identity-by-state relationship matrix and a genomic identity-by-descent relationship matrix (averaged over all marker loci. The identity-by-descent matrix was calculated by linkage analysis using one to five generations of pedigree data. Results We showed that genome-wide breeding values prediction based only on identity-by-descent genomic relationships within the known pedigree was as or more reliable than that based on identity-by-state, which implicitly also accounts for genomic relationships that occurred before the known pedigree. Furthermore, combining the two matrices did not improve the prediction compared to using identity-by-descent alone. Including different numbers of generations in the pedigree showed that most of the information in genome-wide breeding values prediction comes from animals with known common ancestors less than four generations back in the pedigree. Conclusions Our results show that, in pedigreed breeding populations, the accuracy of genome-wide breeding values obtained by identity-by-descent relationships was not improved by identity-by-state information. Although, in principle, genomic selection based on identity-by-state does not require

Trends in Menarcheal Age between 1955 and 2009 in the Netherlands

NARCIS (Netherlands)

Talma, H.; Schonbeck, Y.; van Dommelen, P.; Bakker, B.; van Buuren, S.; Hirasing, R.A.

2013-01-01

Aim: To assess and compare the secular trend in age at menarche in Dutch girls (1955-2009) and girls from Turkish and Moroccan descent living in the Netherlands (1997-2009). Methods: Data on growth and maturation were collected in 20,867 children of Dutch, Turkish and Moroccan descent in 2009 by

Trends in menarcheal age between 1955 and 2009 in the Netherlands

NARCIS (Netherlands)

Talma, H.; Schönbeck, Y.; Dommelen, P. van; Bakker, B.; Buuren, S. van; Hirasing, R.

2013-01-01

Aim: To assess and compare the secular trend in age at menarche in Dutch girls (1955-2009) and girls from Turkish and Moroccan descent living in the Netherlands (1997-2009). Methods: Data on growth and maturation were collected in 20,867 children of Dutch, Turkish and Moroccan descent in 2009 by

Prostate cancer disparities in Black men of African descent: a comparative literature review of prostate cancer burden among Black men in the United States, Caribbean, United Kingdom, and West Africa

Directory of Open Access Journals (Sweden)

Reams R Renee

2009-02-01

Full Text Available Abstract Background African American men have the highest prostate cancer morbidity and mortality rates than any other racial or ethnic group in the US. Although the overall incidence of and mortality from prostate cancer has been declining in White men since 1991, the decline in African American men lags behind White men. Of particular concern is the growing literature on the disproportionate burden of prostate cancer among other Black men of West African ancestry in the Caribbean Islands, United Kingdom and West Africa. This higher incidence of prostate cancer observed in populations of African descent may be attributed to the fact that these populations share ancestral genetic factors. To better understand the burden of prostate cancer among men of West African Ancestry, we conducted a review of the literature on prostate cancer incidence, prevalence, and mortality in the countries connected by the Transatlantic Slave Trade. Results Several published studies indicate high prostate cancer burden in Nigeria and Ghana. There was no published literature for the countries Benin, Gambia and Senegal that met our review criteria. Prostate cancer morbidity and/or mortality data from the Caribbean Islands and the United Kingdom also provided comparable or worse prostate cancer burden to that of US Blacks. Conclusion The growing literature on the disproportionate burden of prostate cancer among other Black men of West African ancestry follows the path of the Transatlantic Slave Trade. To better understand and address the global prostate cancer disparities seen in Black men of West African ancestry, future studies should explore the genetic and environmental risk factors for prostate cancer among this group.

Short communication

African Journals Online (AJOL)

abp

2015-05-08

May 8, 2015 ... Abstract. We explored the differences in the perceived HRQoL between children with asthma from Moroccan and Dutch descent and their parents. In total. 33 children (aged 6-18 years) from Moroccan (16) and Dutch descent (17) and their parents participated. All children were currently under treatment in a ...

Free Falling in Stratified Fluids

Science.gov (United States)

Lam, Try; Vincent, Lionel; Kanso, Eva

2017-11-01

Leaves falling in air and discs falling in water are examples of unsteady descents due to complex interaction between gravitational and aerodynamic forces. Understanding these descent modes is relevant to many branches of engineering and science such as estimating the behavior of re-entry space vehicles to studying biomechanics of seed dispersion. For regularly shaped objects falling in homogenous fluids, the motion is relatively well understood. However, less is known about how density stratification of the fluid medium affects the falling behavior. Here, we experimentally investigate the descent of discs in both pure water and in stable linearly stratified fluids for Froude numbers Fr 1 and Reynolds numbers Re between 1000 -2000. We found that stable stratification (1) enhances the radial dispersion of the disc at landing, (2) increases the descent time, (3) decreases the inclination (or nutation) angle, and (4) decreases the fluttering amplitude while falling. We conclude by commenting on how the corresponding information can be used as a predictive model for objects free falling in stratified fluids.

The cardiometabolic syndrome in persons of the African diaspora: challenges and opportunities.

Science.gov (United States)

Schuster, Dara P; Gaillard, Trudy; Osei, Kwame

2007-01-01

Unique genetic traits appear to play a role in the increased rates of hypertension (HTN), glucose dysregulation/diabetes (T2DM), and obesity in persons of African descent. Indeed, with increasing rates of westernization/urbanization and concomitant increases in obesity and T2DM, a similar predisposition to the cardiometabolic syndrome and cardiovascular disease (CVD) can be seen in Africans compared with persons of African descent, with CVD reaching epidemic proportions in many areas of Africa. In addition, the complex relationships of metabolic abnormalities that are unique to individuals of African descent have also been demonstrated in Africans. These include: (1) a dissociation of HTN to insulin resistance; (2) relative favorable lipid profile in the setting of increasing rates of CVD; (3) low levels of visceral adiposity in the setting of obesity and insulin resistance; and (4) a dissociation of insulin sensitivity and adiponectin when compared with Caucasians. Although not well understood, these unique relationships suggest that conventional parameters for CVD do not apply to Africans of persons of African descent.

Fundamental limitations on V/STOL terminal guidance due to aircraft characteristics

Science.gov (United States)

Wolkovitch, J.; Lamont, C. W.; Lochtie, D. W.

1971-01-01

A review is given of limitations on approach flight paths of V/STOL aircraft, including limits on descent angle due to maximum drag/lift ratio. A method of calculating maximum drag/lift ratio of tilt-wing and deflected slipstream aircraft is presented. Derivatives and transfer functions for the CL-84 tilt-wing and X-22A tilt-duct aircraft are presented. For the unaugmented CL-84 in steep descents the transfer function relating descent angle to thrust contains a right-half plane zero. Using optimal control theory, it is shown that this zero causes a serious degradation in the accuracy with which steep flight paths can be followed in the presence of gusts.

On Humans as Animals: Sparring with the beast in Douglas ...

African Journals Online (AJOL)

This paper draws on Charles Darwin's argument in The Descent of Man that humans are animals, and then offers a close reading of Douglas Livingstone's poem “Traffic interlude: Descent from the Tower”. It argues that the poem uses the genre of fable to tell the story of man's internal tussle between intellect and instinct, ...

Divergent mortality trends by ethnicity in Fiji.

Science.gov (United States)

Taylor, Richard; Carter, Karen; Naidu, Shivnay; Linhart, Christine; Azim, Syed; Rao, Chalapati; Lopez, Alan D

2013-12-01

To examine trends in infant mortality rate (IMR), adult mortality and life expectancy (LE) in the two major Fijian ethnic groups since 1975. Estimates of IMR, adult mortality (15-59 years) and LE by ethnicity are calculated from previously unreported Fiji Ministry of Health data and extracted from published sources. Over 1975-2008: IMR decreased from 33 to 20 deaths/1,000 live births in i-Taukei (Fiji Melanesians); and 38 to 18 in Fijians of Indian descent. Increased adult male mortality among i-Taukei and decline among Fijians of Indian descent led to an equal probability of dying in 2007 of 29%; while in female adults the probability trended upwards in i-Taukei to 25%, and declined in Fijians of Indian descent to 17%. Life expectancy in both ethnicities increased until 1985 (to 64 years for males; 68 for females) then forming a plateau in males of both ethnicities, and Fijian females of Indian descent, but declining in i-Taukei females to 66 years in 2007. Despite IMR declines over 1975-2008, LE for i-Taukei and Fijians of Indian descent has not increased since 1985, and has actually decreased in i-Taukei women, consistent with trends in adult mortality (15-59 years). Mortality analyses in Fiji that consider the entire population mask divergent trends in the major ethnic groups. This situation is most likely a consequence of non-communicable disease mortality, requiring further assessment and a strengthened response.

Descent principle in modular Galois theory

Indian Academy of Sciences (India)

Springer Verlag Heidelberg #4 2048 1996 Dec 15 10:16:45

with Drinfeld module theory see Remark 5.2 at the end of the paper. To describe the ... where the elements X1,...,Xm need not be algebraically independent over kq. When ..... In §5 we shall make some motivational and philosophical remarks.

Cocytus: Have you begun your descent?

Science.gov (United States)

Schorge, John O

2015-03-01

The vast majority of trainees entering a fellowship express a sincere interest in pursuing an 'academic career'. However, even the most dedicated souls will find their own path toward that worthy goal fraught with a number of unanticipated hazards--any one of which could result in a fullstop of professional advancement. Of interest, many of the obstacles are actually self-imposed, usually buried within the subconscious self. Without guidance of how to recognize and address these shortcomings, abandonment of one's original career trajectory may be seriously considered, and often acted upon. By the time any one of us has completed training, taken the boards, and gotten to this inflection point, we are at least in our mid- to late-30s. What then, is there to do, about this looming phenomenon, whenever it may occur? Perhaps we can draw comfort from a historical figure who has been there, and done that. His journey embodies the value of mentoring in traversing the succession of personal perils that are commonplace in today's professional environment. Copyright © 2015 Elsevier Inc. All rights reserved.

Decision Profiles of Mexican-Descent Families.

Science.gov (United States)

Baker, Georgianne

An exploratory study of decision-making in families of Mexican heritage was carried out in Phoenix, Arizona. A Normative model of decision rationality and measurement (Family Problem Instrument-FPI) was adapted from previous research. Tape-recorded data were provided by 27 families. Husbands and wives responded separately to family decision…

Anterior abdominal wall ectopic testes: A report of two cases ...

African Journals Online (AJOL)

Undescended testis (UDT) is a common anomaly of the male reproductive system affecting about 2% to 4% of male infants more commonly preterms. If the testis remains in the line of normal descent, it is classified as an UDT. If it is not in the line of normal descent, it is termed an ectopic testis. Common sites of ectopic testes ...

PENDIDIKAN KARAKTER BERBASIS AL-QUR’AN: Penerapan Pola Sistematika Nuzulnya Wahyu (SNW di Pondok Pesantren Hidayatullah Panyula Kabupaten Bone

Directory of Open Access Journals (Sweden)

Afifuddin Afifuddin

2016-07-01

Full Text Available This article discusses about the pattern of descent of revelation systematics applied in hidayatullah boarding school, Panyula, Bone regency. This research focuses on the implementation of the pattern of descent of revelation systematics in accordance with the qur’anic character building at the boarding school. The researcher collected and analized data by using descriptive qualitative. This research found that hidayatullah boarding school has successfully applied educational methods on quranic based to build students’ character. Based on the descent of revelation systematics, it has regenerated and internalized values as what have been done by the Prophet Muhammad in his first dakwah in Mecca. This research aims to give academic contribution to teachers in order to build Islamic character of the students.

RES: Regularized Stochastic BFGS Algorithm

Science.gov (United States)

Mokhtari, Aryan; Ribeiro, Alejandro

2014-12-01

RES, a regularized stochastic version of the Broyden-Fletcher-Goldfarb-Shanno (BFGS) quasi-Newton method is proposed to solve convex optimization problems with stochastic objectives. The use of stochastic gradient descent algorithms is widespread, but the number of iterations required to approximate optimal arguments can be prohibitive in high dimensional problems. Application of second order methods, on the other hand, is impracticable because computation of objective function Hessian inverses incurs excessive computational cost. BFGS modifies gradient descent by introducing a Hessian approximation matrix computed from finite gradient differences. RES utilizes stochastic gradients in lieu of deterministic gradients for both, the determination of descent directions and the approximation of the objective function's curvature. Since stochastic gradients can be computed at manageable computational cost RES is realizable and retains the convergence rate advantages of its deterministic counterparts. Convergence results show that lower and upper bounds on the Hessian egeinvalues of the sample functions are sufficient to guarantee convergence to optimal arguments. Numerical experiments showcase reductions in convergence time relative to stochastic gradient descent algorithms and non-regularized stochastic versions of BFGS. An application of RES to the implementation of support vector machines is developed.

Improving Robot Locomotion Through Learning Methods for Expensive Black-Box Systems

Science.gov (United States)

2013-11-01

in an industrial process, or the prescribed dosage of a drug during development. Definition (Environment Parameter). The environment parameter space...line indicates the deviation of this approximation from the original (right axis scale). The secondary gradient descent optimization over the linear...done through gradient descent on the representational error, cycling through all points one at a. t ime until convergence is reached. Figure 7.5 shows

Assessment of the feasible CTA windows for efficient spacing with energy-neutral CDO

OpenAIRE

Dalmau Codina, Ramon; Prats Menéndez, Xavier

2016-01-01

Continuous descent operations (CDO) with con- trolled times of arrival (CTA) at one or several metering fixes could enable environmentally friendly procedures at the same time that terminal airspace capacity is not compromised. This paper focuses on CTA updates once the descent has been already initiated, assessing the feasible CTA window (and associated fuel consumption) of CDO requiring neither thrust nor speed-brake usage alon...

Native South American genetic structure and prehistory inferred from hierarchical modeling of mtDNA.

Science.gov (United States)

Lewis, Cecil M; Long, Jeffrey C

2008-03-01

Genetic diversity in Native South Americans forms a complex pattern at both the continental and local levels. In comparing the West to the East, there is more variation within groups and smaller genetic distances between groups. From this pattern, researchers have proposed that there is more variation in the West and that a larger, more genetically diverse, founding population entered the West than the East. Here, we question this characterization of South American genetic variation and its interpretation. Our concern arises because others have inferred regional variation from the mean variation within local populations without taking into account the variation among local populations within the same region. This failure produces a biased view of the actual variation in the East. In this study, we analyze the mitochondrial DNA sequence between positions 16040 and 16322 of the Cambridge reference sequence. Our sample represents a total of 886 people from 27 indigenous populations from South (22), Central (3), and North America (2). The basic unit of our analyses is nucleotide identity by descent, which is easily modeled and proportional to nucleotide diversity. We use a forward modeling strategy to fit a series of nested models to identity by descent within and between all pairs of local populations. This method provides estimates of identity by descent at different levels of population hierarchy without assuming homogeneity within populations, regions, or continents. Our main discovery is that Eastern South America harbors more genetic variation than has been recognized. We find no evidence that there is increased identity by descent in the East relative to the total for South America. By contrast, we discovered that populations in the Western region, as a group, harbor more identity by descent than has been previously recognized, despite the fact that average identity by descent within groups is lower. In this light, there is no need to postulate separate founding

Project, Aerodynamic, Thermal and Ballistic Analysis of a Lifting-Body Reentry Vehicle

Directory of Open Access Journals (Sweden)

A. N. Eliseev

2015-01-01

Full Text Available The objective of this article is to assess the prospects for an increasingly maneuverable reentry vehicle (RV of class "lifting body". In this regard, a project aerodynamic thermal and ballistic analysis has been conducted and the results have been compared with some well-known projects of the RV of the same class, made both in our country and abroad.The project analysis begins with finding a position of the "lifting body" vehicle in the classification system. Said classification distribution allows correct formulation of requirements for the conceptual structure of an aerospace vehicle at the initial stage of design in terms of system positions, since just the initial phase of the design often determines the success of the whole program.Then the paper compares design characteristics of the RV of class "lifting body" with vehicles such as X-15 rocket plane, the orbiter "Space Shuttle», M2-F2, HL-10, SV-5, and NASP "Hermes". It also gives a comparative estimate of the "lifting body" RV mass in a wide range of dimensions. The paper shows the sustainability of various landing complexes with reference to the Russian experience in developing the RV " Soyuz", and the conditions for using the vehicles of class "lifting body" in space programs.The aerodynamic analysis uses method for the approximate Newtonian theory to calculate aerodynamic characteristics of the perspective RV of class "lifting body" in the hypersonic descent phase. To obtain the desired aerodynamic performance and reduce balancing weight is contemplated a possibility to provide balance by introducing additional boards. The ballistic analysis considers four modes of descent:1. zero roll descent;2. maximum cross-range descent without restriction;3. maximum cross-range descent with restriction of maximum overload and maximum temperature;4. ballistic descent.To calculate the RV ballistic characteristics a system of equations of the vehicle motion in the atmosphere is used. The vehicle

Haplotype analysis of TP53 polymorphisms, Arg72Pro and Ins16, in BRCA1 and BRCA2 mutation carriers of French Canadian descent

International Nuclear Information System (INIS)

Cavallone, Luca; Arcand, Suzanna L; Maugard, Christine; Ghadirian, Parviz; Mes-Masson, Anne-Marie; Provencher, Diane; Tonin, Patricia N

2008-01-01

The TP53 polymorphisms Arg72Pro (Ex4+199 G>C) and Ins16 (IVS3+24 ins16) have been proposed to modify risk of breast cancer associated with germline BRCA1 and BRCA2 mutations. Allele frequencies of these polymorphisms were investigated to determine if they modify risk in BRCA mutation carriers in breast cancer cases drawn from French Canadian cancer families, a population shown to exhibit strong founder effects. The frequencies of the TP53 alleles, genotypes and haplotypes of 157 index breast cancer cases comprised of 42 BRCA1 mutation carriers, 57 BRCA2 mutation carriers, and 58 BRCA mutation-negative cases, where each case was drawn from independently ascertained families were compared. The effect of TP53 variants on the age of diagnosis was also investigated for these groups. The TP53 polymorphisms were also investigated in 112 women of French Canadian descent with no personal history of cancer. The BRCA mutation-positive groups had the highest frequency of homozygous carriers of the 72Pro allele compared with mutation-negative group. The TP53 polymorphisms exhibited linkage disequilibrium (p < 0.001), where the 72Arg and Ins16minus alleles occurred in strong disequilibrium. The highest frequency of carriers of Ins16minus-72Arg haplotype occurred in the BRCA mutation-negative groups. The BRCA1 mutation carriers homozygous for the 72Pro allele had the youngest ages of diagnosis of breast cancer. However none of these observations were statistically significant. In contrast, the BRCA2 mutation carriers homozygous for the 72Pro allele had a significantly older age of diagnosis of breast cancer (p = 0.018). Moreover, in this group, the mean age of diagnosis of breast cancer in carriers of the Ins16minus-72Arg haplotype was significantly younger than that of the individuals who did not this carry this haplotype (p = 0.009). We observed no significant association of breast cancer risk with TP53 genetic variants based on BRCA1/2 mutation carrier status. Although the

Neonatal outcomes and operative vaginal delivery versus cesarean delivery.

LENUS (Irish Health Repository)

Contag, Stephen A

2010-06-01

We compared outcomes for neonates with forceps-assisted, vacuum-assisted, or cesarean delivery in the second stage of labor. This is a secondary analysis of a randomized trial in laboring, low-risk, nulliparous women at >or=36 weeks\\' gestation. Neonatal outcomes after use of forceps, vacuum, and cesarean were compared among women in the second stage of labor at station +1 or below (thirds scale) for failure of descent or nonreassuring fetal status. Nine hundred ninety women were included in this analysis: 549 (55%) with an indication for delivery of failure of descent and 441 (45%) for a nonreassuring fetal status. Umbilical cord gases were available for 87% of neonates. We found no differences in the base excess (P = 0.35 and 0.78 for failure of descent and nonreassuring fetal status) or frequencies of pH below 7.0 (P = 0.73 and 0.34 for failure of descent and nonreassuring fetal status) among the three delivery methods. Birth outcomes and umbilical cord blood gas values were similar for those neonates with a forceps-assisted, vacuum-assisted, or cesarean delivery in the second stage of labor. The occurrence of significant fetal acidemia was not different among the three delivery methods regardless of the indication.

MEMOIRS OF A GIRLHOOD AMONG GHOSTS WRITTEN BY MAXINE HONG KINGSTON

Directory of Open Access Journals (Sweden)

Desy Khrisdiyanti

2017-04-01

Full Text Available Every generation brings their own voice, no matter how rigorous the elderly retain the cultural values of their ancestors. A novel written by Maxine Hong Kingston –a Chinese American descent- entitled The Woman Warrior: Memoirs of a Girlhood among Ghosts, portraits her struggle to get her own identity between her Chinese and her American identity. A descriptive library research was conducted to reveal the reasons that the Chinese American descents struggled to survive in between both lives. Interdisciplinary approaches are employed to analyze the data in order to obtain comprehensive analysis, among others: psychological, sociological, and literary approaches. Psychological approach is to expound the emotional perspectives of the character shifts. Sociological approach is applied to discuss the socialization process and its connection to the character shift. Likewise, literary approach is to uncover the structure of the work which was the result of Kingston‘s experience and reflection of the phenomena in her real life. The research concludes that the personality change of the Chinese American descents is due to their historical, social, economical, and educational experience. Furthermore, the descents tend to transform their traits closer to the white‘s, which have been their counterpart in the new land, than to their ancestries‘.

A sampling algorithm for segregation analysis

Directory of Open Access Journals (Sweden)

Henshall John

2001-11-01

Full Text Available Abstract Methods for detecting Quantitative Trait Loci (QTL without markers have generally used iterative peeling algorithms for determining genotype probabilities. These algorithms have considerable shortcomings in complex pedigrees. A Monte Carlo Markov chain (MCMC method which samples the pedigree of the whole population jointly is described. Simultaneous sampling of the pedigree was achieved by sampling descent graphs using the Metropolis-Hastings algorithm. A descent graph describes the inheritance state of each allele and provides pedigrees guaranteed to be consistent with Mendelian sampling. Sampling descent graphs overcomes most, if not all, of the limitations incurred by iterative peeling algorithms. The algorithm was able to find the QTL in most of the simulated populations. However, when the QTL was not modeled or found then its effect was ascribed to the polygenic component. No QTL were detected when they were not simulated.

Hiperplasia epitelial focal (doença de Heck em descendente de índios brasileiros: relato de caso Focal epithelial hyperplasia (Heck's disease in Brazilian indian descent: report of a case

Directory of Open Access Journals (Sweden)

Pedro Paulo de Andrade Santos

2007-12-01

Full Text Available A hiperplasia epitelial focal, ou doença de Heck, é uma enfermidade rara, benigna, que afeta a mucosa oral de crianças e adultos jovens de diversas regiões do mundo e em diferentes grupos étnicos, como indígenas e esquimós. Apresenta correlação com o papilomavírus humano (HPV no qual os tipos 13 e 32 têm sido consistentemente detectados nessas lesões. Este artigo relata um caso de uma paciente de 18 anos de idade, descendente de índios potiguares, que compareceu ao serviço de estomatologia da Universidade Federal do Rio Grande do Norte (UFRN, exibindo lesões bem definidas, arredondadas, planas, localizadas em cavidade oral, com tempo de evolução de aproximadamente dois anos. As lesões foram submetidas a biópsias incisionais, constatado-se no exame histopatológico alterações epiteliais, como acantose, cristas epiteliais em forma de "taco de golfe" além de células mitosóides. Esses achados histopatológicos foram compatíveis com a hipótese clínica de hiperplasia epitelial focal (doença de Heck.The focal epithelial hyperplasia or Heck's disease is a benign rare pathology, that affects children and young adults oral mucosal in many world regions, and different ethnic groups, for example Indians and Eskimos. Presents correlation with the subtypes 13 and 32 of human papillomavirus (HPV. This article report a case of an 18-year-old patient, descent of potiguar indian, attended in stomatology service of Federal University of Rio Grande do Norte (UFRN, presenting well defined lesions, round, plane, localized in oral cavity with an evolution of two years. The lesions were submitted to incisional biopsies, verifying in histopathologic exam, epithelial alterations, like acanthosis, epithelial projections in "parquet block of golf" beyond mitosoid cells. These histopathological findings were compatible with clinical hypothesis of focal epithelial hyperplasia (Heck's disease.

Cultural factors in collegiate eating disorder pathology: When family culture clashes with individual culture

OpenAIRE

Tomiyama, AJ; Mann, T

2008-01-01

The authors evaluated the validity of familial enmeshment (extreme proximity in family relationships) as a risk factor for eating disorders across cultural value orientations. They tested the hypothesis that although familial enmeshment may be a risk factor for eating disorder pathology for (1) participants of non-Asian descent or (2) culturally independent participants, enmeshment will not be a risk factor for (1) participants of Asian descent or (2) culturally interdependent participants. P...

Maternal use of acetaminophen, ibuprofen, and acetylsalicylic acid during pregnancy and risk of cryptorchidism

DEFF Research Database (Denmark)

Jensen, Morten Søndergaard; Rebordosa, Cristina; Thulstrup, Ane Marie

2010-01-01

Cyclooxygenase (COX) inhibitors-acetaminophen, ibuprofen and acetylsalicylic acid-have endocrine-disruptive properties in the rainbow trout. In humans, aspirin blocks the androgen response to human chorionic gonadotropin (hCG), and, because hCG-stimulated androgen production in utero is crucial...... for normal testicular descent, exposure to COX inhibitors at vulnerable times during gestation may impair testicular descent. We examined whether prenatal exposure to acetaminophen, ibuprofen, and acetylsalicylic acid was associated with increased occurrence of cryptorchidism....

Spacecraft-to-Earth Communications for Juno and Mars Science Laboratory Critical Events

Science.gov (United States)

Soriano, Melissa; Finley, Susan; Jongeling, Andre; Fort, David; Goodhart, Charles; Rogstad, David; Navarro, Robert

2012-01-01

Deep Space communications typically utilize closed loop receivers and Binary Phase Shift Keying (BPSK) or Quadrature Phase Shift Keying (QPSK). Critical spacecraft events include orbit insertion and entry, descent, and landing.---Low gain antennas--> low signal -to-noise-ratio.---High dynamics such as parachute deployment or spin --> Doppler shift. During critical events, open loop receivers and Multiple Frequency Shift Keying (MFSK) used. Entry, Descent, Landing (EDL) Data Analysis (EDA) system detects tones in real-time.

High Altitude Headache and Acute Mountain Sickness at Moderate Elevations in a Military Population During Battalion-Level Training Exercises

Science.gov (United States)

2012-08-01

activities falling between 2,400 and 3,300m. Ascent and descent profiles were variable according to the unit to which a given Marine was attached. Because all...for full duty status. Participants had ready access to water and medical care and available interventions against AMS included descent , oxygen, and...Acetazolamide Dosage Comparison for Efficacy (PACE) trial. High Alt Med Biol 2006; 7(1): 17-27. 14. Basnyat B, Gertsch JH, Johnson EW, Castro-Marin F

Thermal and hygroscopic expansion characteristics of bamboo

OpenAIRE

Huang, Puxi; Chang, Wen-shao; Ansell, Martin P.; Bowen, Chris R.; Chew, John Y. M.; Adamak, Vana i

2017-01-01

The expansion and contraction of bamboo caused by temperature and moisture variations must be evaluated\\ud if bamboo is to be utilised as a building material. However, detailed expansion data, especially data in the ascent and\\ud descent processes of temperature and moisture are unexplored. The aim of this study is to investigate the expansion\\ud characteristics of Phyllostachys edulis (Moso bamboo) in ascent and descent processes of temperature and moisture.\\ud The measurement of linear ther...

MISSION PROFILE AND DESIGN CHALLENGES FOR MARS LANDING EXPLORATION

OpenAIRE

J. Dong; Z. Sun; W. Rao; Y. Jia; L. Meng; C. Wang; B. Chen

2017-01-01

An orbiter and a descent module will be delivered to Mars in the Chinese first Mars exploration mission. The descent module is composed of a landing platform and a rover. The module will be released into the atmosphere by the orbiter and make a controlled landing on Martian surface. After landing, the rover will egress from the platform to start its science mission. The rover payloads mainly include the subsurface radar, terrain camera, multispectral camera, magnetometer, anemometer to achiev...

Genetic variants associated with warfarin dose in African-American individuals: a genome-wide association study

OpenAIRE

Perera, Minoli A; Cavallari, Larisa H; Limdi, Nita A; Gamazon, Eric R; Konkashbaev, Anuar; Daneshjou, Roxana; Pluzhnikov, Anna; Crawford, Dana C; Wang, Jelai; Liu, Nianjun; Tatonetti, Nicholas; Bourgeois, Stephane; Takahashi, Harumi; Bradford, Yukiko; Burkley, Benjamin M

2013-01-01

Summary BackgroundVKORC1 and CYP2C9 are important contributors to warfarin dose variability, but explain less variability for individuals of African descent than for those of European or Asian descent. We aimed to identify additional variants contributing to warfarin dose requirements in African Americans. MethodsWe did a genome-wide association study of discovery and replication cohorts. Samples from African-American adults (aged ≥18 years) who were taking a stable maintenance dose of warfar...

Optimal Lunar Landing Trajectory Design for Hybrid Engine

OpenAIRE

Cho, Dong-Hyun; Kim, Donghoon; Leeghim, Henzeh

2015-01-01

The lunar landing stage is usually divided into two parts: deorbit burn and powered descent phases. The optimal lunar landing problem is likely to be transformed to the trajectory design problem on the powered descent phase by using continuous thrusters. The optimal lunar landing trajectories in general have variety in shape, and the lunar lander frequently increases its altitude at the initial time to obtain enough time to reduce the horizontal velocity. Due to the increment in the altitude,...

RITD - Re-entry: Inflatable Technology Development in Russian Collaboration

Science.gov (United States)

Heilimo, J.; Harri, A.-M.; Aleksashkin, S.; Koryanov, V.; Arruego, I.; Schmidt, W.; Haukka, H.; Finchenko, V.; Martynov, M.; Ostresko, B.; Ponomarenko, A.; Kazakovtsev, V.; Martin, S.; Siili, T.

2014-04-01

A new generation of inflatable Entry, Descent and Landing System (EDLS) for Mars has been developed. It is used in both the initial atmospheric entry and atmospheric descent before the semi-hard impact of the penetrator into Martian surface. The EDLS applicability to Earth's atmosphere is studied by the EU/RITD [1] project. Project focuses on the analysis and tests of the transonic behaviour of this compact and light weight payload entry system at the Earth re-entry.

Evidence for an autumn downstream migration of Atlantic salmon Salmo salar (Linnaeus) and brown trout Salmo trutta (Linnaeus) parr to the Baltic Sea

Science.gov (United States)

Taal, Imre; Kesler, Martin; Saks, Lauri; Rohtla, Mehis; Verliin, Aare; Svirgsden, Roland; Jürgens, Kristiina; Vetemaa, Markus; Saat, Toomas

2014-06-01

In the eastern Baltic rivers, anadromous salmonid parr are known to smoltify and migrate to the sea from March until June, depending on latitude, climate and hydrological conditions. In this study, we present the first records of autumn descent of brown trout Salmo trutta and Atlantic salmon Salmo salar from the Baltic Sea Basin. Otolith microchemistry analyses revealed that these individuals hatched in freshwater and had migrated to the brackish water shortly prior to capture. The fish were collected in 2006, 2008, 2009 and 2013 from Eru Bay (surface salinity 4.5-6.5 ‰), Gulf of Finland. This relatively wide temporal range of observations indicates that the autumn descent of anadromous salmonids is not a random event. These results imply that autumn descent needs more consideration in the context of the effective stock management, assessment and restoration of Baltic salmonid populations and their habitats.

Five polymorphisms and breast cancer risk: results from the Breast Cancer Association Consortium

DEFF Research Database (Denmark)

Gaudet, Mia M; Milne, Roger L; Cox, Angela

2009-01-01

-study heterogeneity for associations with risk for single-nucleotide polymorphisms (SNP) in CASP10, PGR, and BID. Estimates were imprecise for women of Asian and African descent due to small numbers and lower minor allele frequencies (with the exception of BID SNP). The ORs for each copy of the minor allele were...... to invasive breast cancer risk overall in women of European descent: ECCR4 per-allele OR (95% CI) = 0.99 (0.97-1.02), minor allele frequency = 27.5%; TNF 1.00 (0.95-1.06), 5.0%; CASP10 1.02 (0.98-1.07), 6.5%; PGR 1.02 (0.99-1.06), 15.3%; and BID 0.98 (0.86-1.12), 1.7%. However, we observed significant between...... rs744154, TNF rs361525, CASP10 rs13010627, PGR rs1042838, and BID rs8190315 genotypes among women of European descent....

Cross national study of leisure-time physical activity in Dutch and English populations with ethnic group comparisons.

Science.gov (United States)

de Munter, Jeroen S L; Agyemang, Charles; van Valkengoed, Irene G M; Bhopal, Raj; Zaninotto, Paola; Nazroo, James; Kunst, Anton E; Stronks, Karien

2013-06-01

Variations between countries in leisure-time physical activity (LTPA) can be used to test the convergence thesis, which expects that ethnic minority groups change towards the LTPA levels of the native population of host countries. The aim of this study was to test whether similar differences in LTPA between the native populations of England and the Netherlands are also observed among the Indian and African descent groups living in these countries. We used English and Dutch population-based health surveys that included participants aged 35-60 years of European (n(english) = 14,723, n(dutch) = 567), Indian (n(english) = 1264, n(dutch) = 370) and African-Caribbean (n(english) = 1112, n(dutch) = 689) descent. Levels of LTPA (30-minute walking, any reported cycling, gardening, dancing and playing sports) were estimated with age-sex-standardized prevalence rates. Comparisons among groups were made using adjusted Prevalence Ratios (PRs). Within both countries and compared with the European group, Indian and African groups had lower levels of gardening and cycling, whereas the African groups had higher levels of dancing. Between countries, among the European groups, the Netherlands showed higher prevalence of cycling than England, PR = 2.26 (95% CI: 2.06-2.48), and this was 2.85 (1.94-4.19) among Indian descent, and 2.77 (2.05-3.73) among African descent. For playing sports, this was PR = 1.30 (1.23-1.38), 1.43 (1.24-1.66) and 1.22 (1.10-1.34), whereas for gardening this was PR = 0.71 (0.65-0.78), 0.65 (0.52-0.81) and 0.75 (0.62-0.90), respectively. Walking and dancing showed inconsistent differences between the countries and ethnic groups. This cross-national comparison supports the expectation that LTPA of Indian and African descent groups converge towards the national levels of England and the Netherlands respectively.

Television viewing in low-income latino children: variation by ethnic subgroup and English proficiency.

Science.gov (United States)

Thompson, Darcy A; Matson, Pamela A; Ellen, Jonathan M

2013-02-01

Television viewing is associated with an increased risk for obesity in children. Latino children are at high risk for obesity and yet little is known about differences in television viewing habits within this population. The purpose of this study is to determine if hours of television viewed by young children with low-income Latina mothers differs by maternal ethnic subgroup and English language proficiency. This was a cross-sectional analysis of data from the Welfare, Children, & Families: A Three City Study. Participants were 422 low-income Latina mothers of Mexican and Puerto Rican descent with children ages 0-4 years old. The dependent variable was hours of daily television viewed by the child. The independent variable was maternal ethnic subgroup and English language proficiency. Analyses involved the use of multiple negative binomial regression models, which were adjusted for demographic variables. Multivariable regression analyses showed that compared to children with mothers of Mexican descent, children of mothers of Puerto Rican descent watch more daily television (child television viewing (IRR=1.29, 95% CI 1.04, 1.61). No relationship was found for children of Puerto Rican descent. Child television viewing varies in low-income Latino children by maternal ethnic subgroup and English language proficiency. Interventionists must consider the varying sociocultural contexts of Latino children and their influence on television viewing.

How old are chimpanzee communities? Time to the most recent common ancestor of the Y-chromosome in highly patrilocal societies.

Science.gov (United States)

Langergraber, Kevin E; Rowney, Carolyn; Schubert, Grit; Crockford, Cathy; Hobaiter, Catherine; Wittig, Roman; Wrangham, Richard W; Zuberbühler, Klaus; Vigilant, Linda

2014-04-01

Many human societies are patrilineal, with males passing on their name or descent group affiliation to their offspring. Y-chromosomes are also passed on from father to son, leading to the simple expectation that males sharing the same surname or descent group membership should have similar Y-chromosome haplotypes. Although several studies in patrilineal human societies have examined the correspondence between Y-chromosome variation and surname or descent group membership, similar studies in non-human animals are lacking. Chimpanzees represent an excellent species for examining the relationship between descent group membership and Y-chromosome variation because they live in strongly male philopatric communities that arise by a group-fissioning process. Here we take advantage of recent analytical advances in the calculation of the time to the most recent common male ancestor and a large sample size of 273 Y-chromosome short tandem repeat haplotypes to inform our understanding of the potential ages of eight communities of chimpanzees. We find that the times to the most recent common male ancestor of chimpanzee communities are several hundred to as much as over two thousand years. These genetic estimates of the great time depths of chimpanzee communities accord well with behavioral observations suggesting that community fissions are a very rare event and are similar to genetic estimates of the time depth of patrilineal human groups. Copyright © 2014 Elsevier Ltd. All rights reserved.

Television Viewing in Low-Income Latino Children: Variation by Ethnic Subgroup and English Proficiency

Science.gov (United States)

Matson, Pamela A.; Ellen, Jonathan M.

2013-01-01

Abstract Background Television viewing is associated with an increased risk for obesity in children. Latino children are at high risk for obesity and yet little is known about differences in television viewing habits within this population. The purpose of this study is to determine if hours of television viewed by young children with low-income Latina mothers differs by maternal ethnic subgroup and English language proficiency. Methods This was a cross-sectional analysis of data from the Welfare, Children, & Families: A Three City Study. Participants were 422 low-income Latina mothers of Mexican and Puerto Rican descent with children ages 0–4 years old. The dependent variable was hours of daily television viewed by the child. The independent variable was maternal ethnic subgroup and English language proficiency. Analyses involved the use of multiple negative binomial regression models, which were adjusted for demographic variables. Results Multivariable regression analyses showed that compared to children with mothers of Mexican descent, children of mothers of Puerto Rican descent watch more daily television (television viewing (IRR=1.29, 95% CI 1.04, 1.61). No relationship was found for children of Puerto Rican descent. Conclusions Child television viewing varies in low-income Latino children by maternal ethnic subgroup and English language proficiency. Interventionists must consider the varying sociocultural contexts of Latino children and their influence on television viewing. PMID:23301653

Inquiry-Based Approach to Understanding Common Descent

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Parker, Monica

2010-01-01

In this inquiry-based activity, students catalog external and internal characteristics of four different classes of animals during dissection exercises. On the basis of their accumulated data, students compare and contrast the animals, devise a phylogenetic tree, and provide reasonable characteristics for extinct transitional organisms. (Contains…

PHYSICIAN FRIDERIK PREGL, NOBELIST OF SLOVENIAN DESCENT

Directory of Open Access Journals (Sweden)

Zvonka Zupanič Slavec

2001-07-01

Full Text Available With his Nobel Prize for chemistry in 1923, Friderik (Fritz Pregl (1869–1930, a physician and a university professor for medical chemistry became a famous person both among Slovenians and world’s most eminent scientists. He did not win the Nobel Prize only for his work on the field of microanalysis of organic substances because he would have invented something very new but because he made a significant contribution to the improvement of the methodology in the quantitative organic microanalysis of that time. In his scientific work he focused on reducing the amount of substance designed for the analysis and on the improvement of the analytical scales. He improved the scales’ accuracy to a thousandth of a gram, decreased the amount of testing substance and reduced working time and the energy spared for the work considerably. Consequently, the study of substance was possible also in cases where only 3–5mg of the substance or even less were available. The same amount of substance, which had been sufficient only for one analyse, was now enough to carry out more than 50 analyses. Therefore, his improvements made the work of physiological and pathological chemists more exact and quicker. Scientific success and many publications made Pregl’s name; he became an honorary doctor of the wellknown university in Göttingen, a member of the academy of sciences and arts in Vienna and an honorary citizen of Graz

14 CFR 31.19 - Performance: Uncontrolled descent.

Science.gov (United States)

2010-01-01

... single failure of the heater assembly, fuel cell system, gas value system, or maneuvering vent system, or from any single tear in the balloon envelope between tear stoppers: (1) The maximum vertical velocity attained. (2) The altitude loss from the point of failure to the point at which maximum vertical velocity...

Quasi-coherent Hecke category and Demazure descent

DEFF Research Database (Denmark)

Arkhipov, Sergey; Kanstrup, Tina

2015-01-01

Let G be a reductive algebraic group with a Borel subgroup B. We define the quasi-coherent Hecke category for the pair (G,B). For any regular Noetherian G- scheme X we construct a monoidal action of the Hecke category on the derived category of B-equivariant quasi-coherent sheaves on X. Using the...

CARI NAIRAS: Calculating Flight Doses from NAIRAS Data using CARI

Science.gov (United States)

2014-12-01

S44 (1996). 5. O’Brien, K; Smart, DF; Shea, MA; et al. World-wide radiation dosage calculations for air crew members. Advan Space Res, 2003, 31(4...STEPMIN(I), STEPFEET(I) ENDDO WRITE(40,*) ‘RDBIGFLT RETURNS CRUISE TIME (MIN): ‘,CRUISEMIN WRITE(40,*) ‘RDBIGFLT RETURNS DESCENT TIME (MIN...USE ONE STEP PER MINUTE, CENTERED ON 1/2 STEP IF (DIAGNOSE.EQ.’YES’) WRITE(40,*) ‘CALCULATING DESCENT ’ CALL FT2KM(DALT,DEPTH(ALLSTEPS)) DT(J

Neuromuscular Activity and Knee Kinematics in Adolescents with Patellofemoral Pain

DEFF Research Database (Denmark)

Rathleff, Michael Skovdal; Samani, Afshin; Olesen, Jens L

2013-01-01

This study aimed to investigate the neuromuscular control of the knee during stair descent among female adolescents with patellofemoral pain (PFP) and to report its association with self-reported clinical status assessed by the Knee Injury and Osteoarthritis Outcome Score (KOOS).......This study aimed to investigate the neuromuscular control of the knee during stair descent among female adolescents with patellofemoral pain (PFP) and to report its association with self-reported clinical status assessed by the Knee Injury and Osteoarthritis Outcome Score (KOOS)....

A New Interpolation Approach for Linearly Constrained Convex Optimization

KAUST Repository

Espinoza, Francisco

2012-08-01

In this thesis we propose a new class of Linearly Constrained Convex Optimization methods based on the use of a generalization of Shepard\\'s interpolation formula. We prove the properties of the surface such as the interpolation property at the boundary of the feasible region and the convergence of the gradient to the null space of the constraints at the boundary. We explore several descent techniques such as steepest descent, two quasi-Newton methods and the Newton\\'s method. Moreover, we implement in the Matlab language several versions of the method, particularly for the case of Quadratic Programming with bounded variables. Finally, we carry out performance tests against Matab Optimization Toolbox methods for convex optimization and implementations of the standard log-barrier and active-set methods. We conclude that the steepest descent technique seems to be the best choice so far for our method and that it is competitive with other standard methods both in performance and empirical growth order.

Representaciones sociales sobre afrodescendientes: la aventura cultural, la violencia sexual-género y luchas multidimensionales

Directory of Open Access Journals (Sweden)

Yeison Arcadio Meneses Copete

2014-12-01

Full Text Available The women and men of African descent are represented socially as "objects of cultural adventure". There is a brand that uses gender and sexual-based violence exacerbated by the racialization of the body. it represents, objectifies and "cloisters" women of African descent into the categories of "hot bodies", "gusty", "strong": chained bodies. since social representations shape human behavior and social practices, the discourses and imaginaries of men and women of African descent generate the "disposal" of the relations that they establish with mestizos and other human groups, including their co-ethnic bonds. similarly, these representations make them more prone to sexual violence. For men, there is a continuity in the discourse of "virile male" that "discards", "objectifies" and, in turn, preforms a construction of masculinity, sexuality, sexual identity and the relationship with other sexualities. such representations lead men and women to avoid being affectionate and close in their interactions with the same sex, with their couples and in their social and family relationships.

Higher perceived HRQoL in Moroccan children with asthma and their parents.

Science.gov (United States)

Veenstra-van Schie, Monique Theodora Maria; Coenen, Kelly; Koopman, Hendrik Maria; Versteegh, Florens Gerard Adriaan

2015-01-01

We explored the differences in the perceived HRQoL between children with asthma from Moroccan and Dutch descent and their parents. In total 33 children (aged 6-18 years) from Moroccan (16) and Dutch descent (17) and their parents participated. All children were currently under treatment in a general hospital in the Netherlands. Generic and asthma specific HRQoL were assessed (DUX-25, DISABKIDS, PAQLQ). Significant differences were found on the DUX-25 subscales physical, emotional and home functioning. Children and parents from Dutch descent reported a lower HRQoL. The findings of this study are contrary with previous research. Results can be explained by the individualistic-collectivistic dimension, socially desirability, language and the feeling of miscomprehension. If this explanation makes sense health care workers have to invest in a good relationship with especially immigrant children and their parents, so they will have enough confidence to talk more openly about their physical as well as their psycho-social complaints.

Cultural differences in visual attention: Implications for distraction processing.

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Amer, Tarek; Ngo, K W Joan; Hasher, Lynn

2017-05-01

We investigated differences between participants of East Asian and Western descent in attention to and implicit memory for irrelevant words which participants were instructed to ignore while completing a target task (a Stroop Task in Experiment 1 and a 1-back task on pictures in Experiment 2). Implicit memory was measured using two conceptual priming tasks (category generation in Experiment 1 and general knowledge in Experiment 2). Participants of East Asian descent showed reliable implicit memory for previous distractors relative to those of Western descent with no evidence of differences on target task performance. We also found differences in a Corsi Block spatial memory task in both studies, with superior performance by the East Asian group. Our findings suggest that cultural differences in attention extend to task-irrelevant background information, and demonstrate for the first time that such information can boost performance when it becomes relevant on a subsequent task. © 2016 The British Psychological Society.

Multi-Modal Active Perception for Autonomously Selecting Landing Sites on Icy Moons

Science.gov (United States)

Arora, A.; Furlong, P. M.; Wong, U.; Fong, T.; Sukkarieh, S.

2017-01-01

Selecting suitable landing sites is fundamental to achieving many mission objectives in planetary robotic lander missions. However, due to sensing limitations, landing sites which are both safe and scientifically valuable often cannot be determined reliably from orbit, particularly, in icy moon missions where orbital sensing data is noisy and incomplete. This paper presents an active perception approach to Entry Descent and Landing (EDL) which enables the lander to autonomously plan informative descent trajectories, acquire high quality sensing data during descent and exploit this additional information to select higher utility landing sites. Our approach consists of two components: probabilistic modeling of landing site features and approximate trajectory planning using a sampling based planner. The proposed framework allows the lander to plan long horizons paths and remain robust to noisy data. Results in simulated environments show large performance improvements over alternative approaches and show promise that our approach has strong potential to improve science return of not only icy moon missions but EDL systems in general.

Combining information from linkage and association mapping for next-generation sequencing longitudinal family data.

Science.gov (United States)

Balliu, Brunilda; Uh, Hae-Won; Tsonaka, Roula; Boehringer, Stefan; Helmer, Quinta; Houwing-Duistermaat, Jeanine J

2014-01-01

In this analysis, we investigate the contributions that linkage-based methods, such as identical-by-descent mapping, can make to association mapping to identify rare variants in next-generation sequencing data. First, we identify regions in which cases share more segments identical-by-descent around a putative causal variant than do controls. Second, we use a two-stage mixed-effect model approach to summarize the single-nucleotide polymorphism data within each region and include them as covariates in the model for the phenotype. We assess the impact of linkage disequilibrium in determining identical-by-descent states between individuals by using markers with and without linkage disequilibrium for the first part and the impact of imputation in testing for association by using imputed genome-wide association studies or raw sequence markers for the second part. We apply the method to next-generation sequencing longitudinal family data from Genetic Association Workshop 18 and identify a significant region at chromosome 3: 40249244-41025167 (p-value = 2.3 × 10(-3)).

Incidence of pelvic organ prolapse in Nigerian women.

Science.gov (United States)

Okonkwo, J. E. N.; Obiechina, N. J. A.; Obionu, C. N.

2003-01-01

OBJECTIVE: To establish the incidence and types of utero-vaginal prolapse. METHODS: Retrospective medical records analyses of women who were subjected to reconstructive pelvic surgery for various types of pelvic relaxation at the Nnamdi Azikiwe University Teaching Hospital, Nnewi and the University Of Nigeria Teaching Hospital, Enugu, Nigeria was carried out. The study was conducted from January 1996 to December 1999 during which there were 7515 surgical admissions. The inclusion criteria were those women who complained of feeling a mass in the vagina with demonAstrable descent of the anterior and/or posterior and/or apical vaginal walls and/or perineal descent. Excluded were patients who had other symptoms other than utero-vaginal prolapse and those whose grades and sites of prolapse were not determinable from the clinical or surgical notes. Also excluded were patients with nerve injury or disease, connective tissue disorders and neuromuscular diseases. The subjects were divided into two groups. Group I consisted of 54 women (age or = 40 years). The findings between those two groups were compared with reference to sites, types and degree of prolapse. Also, coexistence of pelvic relaxation and underlying medical conditions were evaluated. RESULTS: A total of 159 subjects out of 492 charts studied met the inclusion criteria for the study. In group I, mean age was 32.839 with a standard deviation (SD) of +/- 6.012 years; and in group II the mean age was 56.543 with a SD of 8.094. Hypertrophic (elongated) cervix was determined in 15 (6.3%) subjects in group I for an incidence of 1.58% per year, cystocele (vaginal anterior wall descent) was present in 21 (8.9%) women for an incidence of 2.2% per year; rectocele (posterior vaginal wall descent) was identified in 15 (6.3%) women for an incidence of 1.58% per year; vaginal cough prolapse (apical descent) was present 21 (8.9%) women for an incidence of 2.2% per year. Perineal descent was absent in this group. In group II

Incidence of pelvic organ prolapse in Nigerian women.

Science.gov (United States)

Okonkwo, J E N; Obiechina, N J A; Obionu, C N

2003-02-01

To establish the incidence and types of utero-vaginal prolapse. Retrospective medical records analyses of women who were subjected to reconstructive pelvic surgery for various types of pelvic relaxation at the Nnamdi Azikiwe University Teaching Hospital, Nnewi and the University Of Nigeria Teaching Hospital, Enugu, Nigeria was carried out. The study was conducted from January 1996 to December 1999 during which there were 7515 surgical admissions. The inclusion criteria were those women who complained of feeling a mass in the vagina with demonAstrable descent of the anterior and/or posterior and/or apical vaginal walls and/or perineal descent. Excluded were patients who had other symptoms other than utero-vaginal prolapse and those whose grades and sites of prolapse were not determinable from the clinical or surgical notes. Also excluded were patients with nerve injury or disease, connective tissue disorders and neuromuscular diseases. The subjects were divided into two groups. Group I consisted of 54 women (age or = 40 years). The findings between those two groups were compared with reference to sites, types and degree of prolapse. Also, coexistence of pelvic relaxation and underlying medical conditions were evaluated. A total of 159 subjects out of 492 charts studied met the inclusion criteria for the study. In group I, mean age was 32.839 with a standard deviation (SD) of +/- 6.012 years; and in group II the mean age was 56.543 with a SD of 8.094. Hypertrophic (elongated) cervix was determined in 15 (6.3%) subjects in group I for an incidence of 1.58% per year, cystocele (vaginal anterior wall descent) was present in 21 (8.9%) women for an incidence of 2.2% per year; rectocele (posterior vaginal wall descent) was identified in 15 (6.3%) women for an incidence of 1.58% per year; vaginal cough prolapse (apical descent) was present 21 (8.9%) women for an incidence of 2.2% per year. Perineal descent was absent in this group. In group II, there was no hypertrophic

Effect of exercise therapy on neuromuscular activity and knee strength in female adolescents with patellofemoral pain

DEFF Research Database (Denmark)

Rathleff, Michael S.; Samani, Afshin; Olesen, Jens L.

2016-01-01

. A random subsample of 57 female adolescents was included and tested at baseline and after 3months. Neuromuscular control of the knee was quantified as the complexity of surface electromyography of the vastus lateralis and vastus medialis during stair descent. Secondary outcomes were complexity of knee...... during stair descent than those receiving patient education alone. This suggest that exercise therapy has an effect not only on self-reported outcome measures but also on objective measures of thigh muscle function in female adolescents with patellofemoral pain....

Investigating the possibility of the CONSERT instrument operating as a bi-static RADAR sounder during the seperation, descent and landing phase of the ROSETTA mission

Science.gov (United States)

Statz, C.; Hegler, S.; Plettemeier, D.; Berquin, Y. P.; Herique, A.; Kofman, W. W.

2012-12-01

The main scientific objective of the Comet Nucleus Sounding Experiment by Radiowave Transmission (CONSERT) is to determine the dielectric properties of comet 67P/Chuyurmov-Gerasimenko's nucleus. This will be achieved by performing a sounding of the comet's core between the lander "Philae" launched on the comet's surface and the orbiter "Rosetta". For the sounding the lander will receive, process and retransmit the radio signal emitted by the CONSERT instrument aboard the orbiter. With data measured during the first science phase, a three-dimensional model of the material distribution with regard to the complex dielectric permittivity of the comet's nucleus is to be reconstructed. In order to increase the scientific outcome of the experiment and to collect data beneficial for the main scientific objective, it may be considered to operate the CONSERT instrument as a bi-static RADAR sounder during the non mission-critical parts of the separation, descent and landing (SDL) phase, i.e. when the lander is launched onto the comet's surface, of the ROSETTA mission. The data measured during this phase will be mainly echoes from the comet's surface and first meters of subsurface. Based on this data, we intent to create an initial dielectric permittivity mapping of the comet's surface at and around the landing site In order to estimate the performance of the instrument in this special operational mode, simulations of a sounding in SDL configuration were performed. The simulations are based on a hybrid method-of-moments physical-optics (EFIE-DPO) approach for large dielectric bodies with consideration of the behavior of the instrument's antennas and coupling with the spacecraft as well as polarization effects. The simulated results are furthermore processed in a system-level-instrument-simulator to include effects such as a realistic sounding signal, pulse-compression and analog digital conversion in the estimation of the sounding capabilities. The main objective of the

MISSION PROFILE AND DESIGN CHALLENGES FOR MARS LANDING EXPLORATION

Directory of Open Access Journals (Sweden)

J. Dong

2017-07-01

Full Text Available An orbiter and a descent module will be delivered to Mars in the Chinese first Mars exploration mission. The descent module is composed of a landing platform and a rover. The module will be released into the atmosphere by the orbiter and make a controlled landing on Martian surface. After landing, the rover will egress from the platform to start its science mission. The rover payloads mainly include the subsurface radar, terrain camera, multispectral camera, magnetometer, anemometer to achieve the scientific investigation of the terrain, soil characteristics, material composition, magnetic field, atmosphere, etc. The landing process is divided into three phases (entry phase, parachute descent phase and powered descent phase, which are full of risks. There exit lots of indefinite parameters and design constrain to affect the selection of the landing sites and phase switch (mortaring the parachute, separating the heat shield and cutting off the parachute. A number of new technologies (disk-gap-band parachute, guidance and navigation, etc. need to be developed. Mars and Earth have gravity and atmosphere conditions that are significantly different from one another. Meaningful environmental conditions cannot be recreated terrestrially on earth. A full-scale flight validation on earth is difficult. Therefore the end-to-end simulation and some critical subsystem test must be considered instead. The challenges above and the corresponding design solutions are introduced in this paper, which can provide reference for the Mars exploration mission.

Designing of deployment sequence for braking and drift systems in atmosphere of Mars and Venus

Science.gov (United States)

Vorontsov, Victor

2006-07-01

Analysis of project development and space research using contact method, namely, by means of automatic descent modules and balloons shows that designing formation of entry, descent and landing (EDL) sequence and operation in the atmosphere are of great importance. This process starts at the very beginning of designing, has undergone a lot of iterations and influences processing of normal operation results. Along with designing of descent module systems, including systems of braking in the atmosphere, designing of flight operation sequence and trajectories of motion in the atmosphere is performed. As the entire operation sequence and transfer from one phase to another was correctly chosen, the probability of experiment success on the whole and efficiency of application of various systems vary. By now the most extensive experience of Russian specialists in research of terrestrial planets has been gained with the help of automatic interplanetary stations “Mars”, “Venera”, “Vega” which had descent modules and drifting in the atmosphere balloons. Particular interest and complicity of formation of EDL and drift sequence in the atmosphere of these planets arise from radically different operation conditions, in particular, strongly rarefied atmosphere of the one planet and extremely dense atmosphere of another. Consequently, this determines the choice of braking systems and their parameters and method of EDL consequence formation. At the same time there are general fundamental methods and designed research techniques that allowed taking general technical approach to designing of EDL and drift sequence in the atmosphere.

Assessment of patient functional performance in different knee arthroplasty designs during unconstrained squat.

Science.gov (United States)

Verdini, Federica; Zara, Claudio; Leo, Tommaso; Mengarelli, Alessandro; Cardarelli, Stefano; Innocenti, Bernardo

2017-01-01

In this paper, squat named by Authors unconstrained because performed without constrains related to feet position, speed, knee maximum angle to be reached, was tested as motor task revealing differences in functional performance after knee arthroplasty. It involves large joints ranges of motion, does not compromise joint safety and requires accurate control strategies to maintain balance. Motion capture techniques were used to study squat on a healthy control group (CTR) and on three groups, each characterised by a specific knee arthroplasty design: a Total Knee Arthroplasty (TKA), a Mobile Bearing and a Fixed Bearing Unicompartmental Knee Arthroplasty (respectively MBUA and FBUA). Squat was analysed during descent, maintenance and ascent phase and described by speed, angular kinematics of lower and upper body, the Center of Pressure (CoP) trajectory and muscle activation timing of quadriceps and biceps femoris. Compared to CTR, for TKA and MBUA knee maximum flexion was lower, vertical speed during descent and ascent reduced and the duration of whole movement was longer. CoP mean distance was higher for all arthroplasty groups during descent as higher was, CoP mean velocity for MBUA and TKA during ascent and descent. Unconstrained squat is able to reveal differences in the functional performance among control and arthroplasty groups and between different arthroplasty designs. Considering the similarity index calculated for the variables showing statistically significance, FBUA performance appears to be closest to that of the CTR group. III a.

Assessment of patient functional performance in different knee arthroplasty designs during unconstrained squat

Science.gov (United States)

Verdini, Federica; Zara, Claudio; Leo, Tommaso; Mengarelli, Alessandro; Cardarelli, Stefano; Innocenti, Bernardo

2017-01-01

Summary Background In this paper, squat named by Authors unconstrained because performed without constrains related to feet position, speed, knee maximum angle to be reached, was tested as motor task revealing differences in functional performance after knee arthroplasty. It involves large joints ranges of motion, does not compromise joint safety and requires accurate control strategies to maintain balance. Methods Motion capture techniques were used to study squat on a healthy control group (CTR) and on three groups, each characterised by a specific knee arthroplasty design: a Total Knee Arthroplasty (TKA), a Mobile Bearing and a Fixed Bearing Unicompartmental Knee Arthroplasty (respectively MBUA and FBUA). Squat was analysed during descent, maintenance and ascent phase and described by speed, angular kinematics of lower and upper body, the Center of Pressure (CoP) trajectory and muscle activation timing of quadriceps and biceps femoris. Results Compared to CTR, for TKA and MBUA knee maximum flexion was lower, vertical speed during descent and ascent reduced and the duration of whole movement was longer. CoP mean distance was higher for all arthroplasty groups during descent as higher was, CoP mean velocity for MBUA and TKA during ascent and descent. Conclusions Unconstrained squat is able to reveal differences in the functional performance among control and arthroplasty groups and between different arthroplasty designs. Considering the similarity index calculated for the variables showing statistically significance, FBUA performance appears to be closest to that of the CTR group. Level of evidence III a. PMID:29387646

Volumization of the Brow at the Time of Blepharoplasty: Treating the Eyebrow Fat Pad as an Independent Unit.

Science.gov (United States)

Vrcek, Ivan; Chou, Eva; Somogyi, Marie; Shore, John W

Loss of volume in the sub-brow fat pad with associated descent of the eyebrow is a common anatomical finding resulting in both functional and aesthetic consequences. A variety of techniques have been described to address brow position at the time of blepharoplasty. To our knowledge, none of these techniques treat the sub-brow fat pad as an isolated unit. Doing so enables the surgeon to stabilize and volumize the brow without resultant tension on the blepharoplasty wound. The authors describe a technique for addressing volume loss in the eyebrow with associated brow descent that treats the sub-brow fat pad as an isolated unit. A retrospective review of all patients undergoing brow ptosis repair by a single surgeon (J.W.S.) over an 11-month period was performed. Eighteen patients and 33 brows underwent the technique described. Patients were followed for an average of 11 weeks (range: 4 weeks to 20 weeks). All patients preoperatively displayed both visually significant dermatochalasis and brow descent below the orbital rim. Evaluation of pre- and postoperative photos demonstrates successful volumization of the brow with skin redraping without focal dimpling or undue tension on the eyelid wound. Performing a dissection that allows the sub-brow fat pad to be elevated in isolation from the overlying orbicularis and underlying periosteum allows for volumization and of the brow without compromising closure. This technique is a safe and effective means of volumizing the brow and treating secondary brow descent.

The effectiveness of ground level post-flight 100 percent oxygen breathing as therapy for pain-only altitude Decompression Sickness (DCS)

Science.gov (United States)

Demboski, John T.; Pilmanis, Andrew A.

1994-01-01

In both the aviation and space environments, decompression sickness (DCS) is an operational limitation. Hyperbaric recompression is the most efficacious treatment for altitude DCS. However, the inherent recompression of descent to ground level while breathing oxygen is in itself therapy for altitude DCS. If pain-only DCS occurs during a hypobaric exposure, and the symptoms resolver during descent, ground level post-flight breathing of 100% O2 for 2 hours (GLO2) is considered sufficient treatment by USAF Regulation 161-21. The effectiveness of the GLO2 treatment protocol is defined.

Cina Benteng: The Latest Generations and Acculturation

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Billy Nathan Setiawan

2015-05-01

Full Text Available The aim of this paper was to investigate the acculturation process encountered by the two latest generations of Cina Benteng. A Skype interview was conducted with two young Cina Benteng descents. The analysis was also supported by insightful remark from the parents of the two interviewees. This study discovers that the two generations seem to respond to the acculturation process in different ways. However, although some traditions are no longer relevant to the later generation, their identity as a Chinese descent cannot be easily removed.

A stratospheric balloon experiment to test the Huygens atmospheric structure instrument (HASI)

Science.gov (United States)

Fulchignoni, M.; Aboudan, A.; Angrilli, F.; Antonello, M.; Bastianello, S.; Bettanini, C.; Bianchini, G.; Colombatti, G.; Ferri, F.; Flamini, E.; Gaborit, V.; Ghafoor, N.; Hathi, B.; Harri, A.-M.; Lehto, A.; Lion Stoppato, P. F.; Patel, M. R.; Zarnecki, J. C.

2004-08-01

We developed a series of balloon experiments parachuting a 1:1 scale mock-up of the Huygens probe from an altitude just over 30 km to simulate at planetary scale the final part of the descent of the probe through Titan's lower atmosphere. The terrestrial atmosphere represents a natural laboratory where most of the physical parameters meet quite well the bulk condition of Titan's environment, in terms of atmosphere composition, pressure and mean density ranges, though the temperature range will be far higher. The probe mock-up consists of spares of the HASI sensor packages, housekeeping sensors and other dedicated sensors, and also incorporates the Huygens Surface Science Package (SSP) Tilt sensor and a modified version of the Beagle 2 UV sensor, for a total of 77 acquired sensor channels, sampled during ascent, drift and descent phase. An integrated data acquisition and instrument control system, simulating the HASI data-processing unit (DPU), has been developed, based on PC architecture and soft-real-time application. Sensor channels were sampled at the nominal HASI data rates, with a maximum rate of 1 kHz. Software has been developed for data acquisition, onboard storage and telemetry transmission satisfying all requests for real-time monitoring, diagnostic and redundancy. The mock-up of the Huygens probe mission was successfully launched for the second time (first launch in summer 2001, see Gaborit et al., 2001) with a stratospheric balloon from the Italian Space Agency Base "Luigi Broglio" in Sicily on May 30, 2002, and recovered with all sensors still operational. The probe was lifted to an altitude of 32 km and released to perform a parachuted descent lasting 53 min, to simulate the Huygens mission at Titan. Preliminary aerodynamic study of the probe has focused upon the achievement of a descent velocity profile reproducing the expected profile of Huygens probe descent into Titan. We present here the results of this experiment discussing their relevance in

Reconstructing the Surface Permittivity Distribution from Data Measured by the CONSERT Instrument aboard Rosetta: Method and Simulations

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Plettemeier, D.; Statz, C.; Hegler, S.; Herique, A.; Kofman, W. W.

2014-12-01

One of the main scientific objectives of the Comet Nucleus Sounding Experiment by Radiowave Transmission (CONSERT) aboard Rosetta is to perform a dielectric characterization of comet 67P/Chuyurmov-Gerasimenko's nucleus by means of a bi-static sounding between the lander Philae launched onto the comet's surface and the orbiter Rosetta. For the sounding, the lander part of CONSERT will receive and process the radio signal emitted by the orbiter part of the instrument and transmit a signal to the orbiter to be received by CONSERT. CONSERT will also be operated as bi-static RADAR during the descent of the lander Philae onto the comet's surface. From data measured during the descent, we aim at reconstructing a surface permittivity map of the comet at the landing site and along the path below the descent trajectory. This surface permittivity map will give information on the bulk material right below and around the landing site and the surface roughness in areas covered by the instrument along the descent. The proposed method to estimate the surface permittivity distribution is based on a least-squares based inversion approach in frequency domain. The direct problem of simulating the wave-propagation between lander and orbiter at line-of-sight and the signal reflected on the comet's surface is modelled using a dielectric physical optics approximation. Restrictions on the measurement positions by the descent orbitography and limitations on the instrument dynamic range will be dealt with by application of a regularization technique where the surface permittivity distribution and the gradient with regard to the permittivity is projected in a domain defined by a viable model of the spatial material and roughness distribution. The least-squares optimization step of the reconstruction is performed in such domain on a reduced set of parameters yielding stable results. The viability of the proposed method is demonstrated by reconstruction results based on simulated data.

Stair negotiation time in community-dwelling older adults: normative values and association with functional decline.

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Oh-Park, Mooyeon; Wang, Cuiling; Verghese, Joe

2011-12-01

To establish reference values for stair ascent and descent times in community-dwelling, ambulatory older adults, and to examine their predictive validity for functional decline. Longitudinal cohort study. Mean follow-up time was 1.8 years (maximum, 3.2y; total, 857.9 person-years). Community sample. Adults 70 years and older (N=513; mean age, 80.8 ± 5.1y) without disability or dementia. Not applicable. Time to ascend and descend 3 steps measured at baseline. A 14-point disability scale assessed functional status at baseline and at follow-up interviews every 2 to 3 months. Functional decline was defined as an increase in the disability score by 1 point during the follow-up period. The mean±SD stair ascent and descent times for 3 steps were 2.78 ± 1.49 and 2.83 ± 1.61 seconds, respectively. The proportion of self-reported and objective difficulty was higher with longer stair ascent and descent times (PRehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Intrarectal pressures and balloon expulsion related to evacuation proctography.

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Halligan, S; Thomas, J; Bartram, C

1995-01-01

Seventy four patients with constipation were examined by standard evacuation proctography and then attempted to expel a small, non-deformable rectal balloon, connected to a pressure transducer to measure intrarectal pressure. Simultaneous imaging related the intrarectal position of the balloon to rectal deformity. Inability to expel the balloon was associated proctographically with prolonged evacuation, incomplete evacuation, reduced anal canal diameter, and acute anorectal angulation during evacuation. The presence and size of rectocoele or intussusception was unrelated to voiding of paste or balloon. An independent linear combination of pelvic floor descent and evacuation time on proctography correctly predicted maximum intrarectal pressure in 74% of cases. No patient with both prolonged evacuation and reduced pelvic floor descent on proctography could void the balloon, as maximum intrarectal pressure was reduced in this group. A prolonged evacuation time on proctography, in combination with reduced pelvic floor descent, suggests defecatory disorder may be caused by inability to raise intrarectal pressure. A diagnosis of anismus should not be made on proctography solely on the basis of incomplete/prolonged evacuation, as this may simply reflect inadequate straining. PMID:7672656

Large Airborne Full Tensor Gradient Data Inversion Based on a Non-Monotone Gradient Method

Science.gov (United States)

Sun, Yong; Meng, Zhaohai; Li, Fengting

2018-03-01

Following the development of gravity gradiometer instrument technology, the full tensor gravity (FTG) data can be acquired on airborne and marine platforms. Large-scale geophysical data can be obtained using these methods, making such data sets a number of the "big data" category. Therefore, a fast and effective inversion method is developed to solve the large-scale FTG data inversion problem. Many algorithms are available to accelerate the FTG data inversion, such as conjugate gradient method. However, the conventional conjugate gradient method takes a long time to complete data processing. Thus, a fast and effective iterative algorithm is necessary to improve the utilization of FTG data. Generally, inversion processing is formulated by incorporating regularizing constraints, followed by the introduction of a non-monotone gradient-descent method to accelerate the convergence rate of FTG data inversion. Compared with the conventional gradient method, the steepest descent gradient algorithm, and the conjugate gradient algorithm, there are clear advantages of the non-monotone iterative gradient-descent algorithm. Simulated and field FTG data were applied to show the application value of this new fast inversion method.

Fetal topographical anatomy of the female urethra and descending vagina: a histological study of the early human fetal urethra.

Science.gov (United States)

Masumoto, Hiroshi; Rodríguez-Vázquez, Jose Francisco; Verdugo-López, Samuel; Murakami, Gen; Matsubara, Akio

2011-12-20

Which parts of the male urethra correspond to the female urethra? To resolve this question, we need to understand fetal topographical changes in the urethra, its external sphincter and vagina. The vagina joins the mid-course of the primitive urethra and, later "descends" to the vaginal vestibulum. We examined histological sections of 14 female and 4 male mid-term fetuses. The inferior end of the vagina was consistently embedded in the posterior wall of the urethra at 9-12 weeks. The supero-inferior level of the vaginal merging was lower in larger fetuses. Thus, the sequential variation in levels appeared to reflect the process of vaginal descent. However, in spite of penetration of the vaginal end into the posterior urethral wall, we found no sign of destruction of the urethral wall after vaginal descent in the low-merging types. Before vaginal descent, the female external sphincter extended posterolaterally around the urethra. The vaginal descent is classically regarded as a relative topographical change, but it is likely to be a result of elongation of the proximal urethra in the superior side of the vaginal merging. Conversely, the distal urethra is likely to be incorporated into the vaginal vestibulum by 15 weeks. During these processes, most of the female external sphincter seems to be expelled from the original anterior position into the vestibular wall as the urethrovaginal sphincter. The adult female urethra seems to correspond to the male prostatic urethra superior to the prostatic colliculus. Copyright © 2011 Elsevier GmbH. All rights reserved.

Hand and foot pressures in the aye-aye (Daubentonia madagascariensis) reveal novel biomechanical trade-offs required for walking on gracile digits.

Science.gov (United States)

Kivell, Tracy L; Schmitt, Daniel; Wunderlich, Roshna E

2010-05-01

Arboreal animals with prehensile hands must balance the complex demands of bone strength, grasping and manipulation. An informative example of this problem is that of the aye-aye (Daubentonia madagascariensis), a rare lemuriform primate that is unusual in having exceptionally long, gracile fingers specialized for foraging. In addition, they are among the largest primates to engage in head-first descent on arboreal supports, a posture that should increase loads on their gracile digits. We test the hypothesis that aye-ayes will reduce pressure on their digits during locomotion by curling their fingers off the substrate. This hypothesis was tested using simultaneous videographic and pressure analysis of the hand, foot and digits for five adult aye-ayes during horizontal locomotion and during ascent and descent on a 30 degrees instrumented runway. Aye-ayes consistently curled their fingers during locomotion on all slopes. When the digits were in contact with the substrate, pressures were negligible and significantly less than those experienced by the palm or pedal digits. In addition, aye-ayes lifted their hands vertically off the substrate instead of 'toeing-off' and descended head-first at significantly slower speeds than on other slopes. Pressure on the hand increased during head-first descent relative to horizontal locomotion but not as much as the pressure increased on the foot during ascent. This distribution of pressure suggests that aye-ayes shift their weight posteriorly during head-first descent to reduce loads on their gracile fingers. This research demonstrates several novel biomechanical trade-offs to deal with complex functional demands on the mammalian skeleton.

Particle swarm optimization-based automatic parameter selection for deep neural networks and its applications in large-scale and high-dimensional data.

Science.gov (United States)

Ye, Fei

2017-01-01

In this paper, we propose a new automatic hyperparameter selection approach for determining the optimal network configuration (network structure and hyperparameters) for deep neural networks using particle swarm optimization (PSO) in combination with a steepest gradient descent algorithm. In the proposed approach, network configurations were coded as a set of real-number m-dimensional vectors as the individuals of the PSO algorithm in the search procedure. During the search procedure, the PSO algorithm is employed to search for optimal network configurations via the particles moving in a finite search space, and the steepest gradient descent algorithm is used to train the DNN classifier with a few training epochs (to find a local optimal solution) during the population evaluation of PSO. After the optimization scheme, the steepest gradient descent algorithm is performed with more epochs and the final solutions (pbest and gbest) of the PSO algorithm to train a final ensemble model and individual DNN classifiers, respectively. The local search ability of the steepest gradient descent algorithm and the global search capabilities of the PSO algorithm are exploited to determine an optimal solution that is close to the global optimum. We constructed several experiments on hand-written characters and biological activity prediction datasets to show that the DNN classifiers trained by the network configurations expressed by the final solutions of the PSO algorithm, employed to construct an ensemble model and individual classifier, outperform the random approach in terms of the generalization performance. Therefore, the proposed approach can be regarded an alternative tool for automatic network structure and parameter selection for deep neural networks.

The 3D Recognition, Generation, Fusion, Update and Refinement (RG4) Concept

Science.gov (United States)

Maluf, David A.; Cheeseman, Peter; Smelyanskyi, Vadim N.; Kuehnel, Frank; Morris, Robin D.; Norvig, Peter (Technical Monitor)

2001-01-01

This paper describes an active (real time) recognition strategy whereby information is inferred iteratively across several viewpoints in descent imagery. We will show how we use inverse theory within the context of parametric model generation, namely height and spectral reflection functions, to generate model assertions. Using this strategy in an active context implies that, from every viewpoint, the proposed system must refine its hypotheses taking into account the image and the effect of uncertainties as well. The proposed system employs probabilistic solutions to the problem of iteratively merging information (images) from several viewpoints. This involves feeding the posterior distribution from all previous images as a prior for the next view. Novel approaches will be developed to accelerate the inversion search using novel statistic implementations and reducing the model complexity using foveated vision. Foveated vision refers to imagery where the resolution varies across the image. In this paper, we allow the model to be foveated where the highest resolution region is called the foveation region. Typically, the images will have dynamic control of the location of the foveation region. For descent imagery in the Entry, Descent, and Landing (EDL) process, it is possible to have more than one foveation region. This research initiative is directed towards descent imagery in connection with NASA's EDL applications. Three-Dimensional Model Recognition, Generation, Fusion, Update, and Refinement (RGFUR or RG4) for height and the spectral reflection characteristics are in focus for various reasons, one of which is the prospect that their interpretation will provide for real time active vision for automated EDL.

IMMEDIATE EFFECT OF KINESIO VERSUS MCCONNELL TAPING ON PATELLOFEMORAL PAIN SYNDROME DURING FUNCTIONAL ACTIVITIES- A COMPARATIVE STUDY

Directory of Open Access Journals (Sweden)

Sai Kumar. N

2015-12-01

Full Text Available Background: Patellofemoral pain syndrome (PFPS is a condition presenting with anterior knee pain or pain behind the patella (retro-patellar pain. The purpose of the study is to find the immediate effect of Kinesio taping versus McConnell taping in patellofemoral pain syndrome subjects during functional activities- stair ascent, stair descent and squat lift. Methods: An experimental study design with three groups, 45 subjects with patellofemoral pain syndrome was randomized. 15 subjects into each Kinesiotaping group, McConnell group and Sham group. Kinesiotaping group received patellofemoral kinesio taping technique, McConnell group received McConnell taping technique and Sham group received sham taping technique. Outcome measure pain was measured using visual analogue scale during pre and post taping pain levels that were measured during three functional activities: stair ascent, stair descent and squat lift. Results: When analysed within the group using paired ‘t’ test and wilcoxon signed rank test, there is statistically significant improvement in post pain levels in KT, MT and Sham group during stair climbing, stair descent and squat lift. When compared measuring of pre and post pain levels between three groups, there is no significant change in pain level between Kinesio taping and McConnell taping as also compared to sham taping. Conclusion: The study concluded that Kinesio taping, McConnell taping and sham taping shown immediate effect on reducing pain during functional activities such as stair climbing, stair descent and squat lift with greater percentage of pain reduction was found following Kinesiotaping and McConnell taping.

Cosmeceuticals: efficacy and influence on skin tone.

Science.gov (United States)

Draelos, Zoe Diana

2014-04-01

Cosmeceuticals are understood to be active cosmetics that are sold over-the-counter, but have profound effects on skin appearance and functioning. This term has no legal meaning in the United States, because only cosmetics and pharmaceuticals are recognized by regulatory bodies. Cosmeceuticals are carefully developed and tested by the cosmetics industry to deliver consumer-recognizable benefits, with an excellent safety profile. Persons use these products worldwide, including those of African descent, for improvement of skin tone. This article discusses the issues surrounding cosmeceutical use by persons of African descent. Copyright © 2014 Elsevier Inc. All rights reserved.

CAUSES AND CONSEQUENCES OF A CATASTROPHIC MUDFLOWS ON 28 JUNE 2014 NEAR ARSHAN VILLAGE IN THE REPUBLIC OF BURYATIA, RUSSIA

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V. K. Laperdin

2014-01-01

Full Text Available On 28 June 2014, Arshan village and its heath resort facilities suffered from a shock descent of mudflows from Tunka Goltsy in the Republic of Buryatia, Russia. In this region, the last mudflow descent was recorded in 1971. The article provides an overview of the local natural environment of the site where the mudflows descended and the Kyngarga river flooding took place. Preliminary recommendations are given to ensure protection of the local population and regional infrastructure facilities from natural hazardous phenomena that are typical of sides of riftogenic basins located in the Baikal region. 

Global Convergence of a Spectral Conjugate Gradient Method for Unconstrained Optimization

Directory of Open Access Journals (Sweden)

Jinkui Liu

2012-01-01

Full Text Available A new nonlinear spectral conjugate descent method for solving unconstrained optimization problems is proposed on the basis of the CD method and the spectral conjugate gradient method. For any line search, the new method satisfies the sufficient descent condition gkTdk<−∥gk∥2. Moreover, we prove that the new method is globally convergent under the strong Wolfe line search. The numerical results show that the new method is more effective for the given test problems from the CUTE test problem library (Bongartz et al., 1995 in contrast to the famous CD method, FR method, and PRP method.

Past and present African citizenships of slave descent

DEFF Research Database (Denmark)

Hahonou, Eric Komlavi

2011-01-01

This paper takes up the notion of citizenship and ethnicity as forms of belonging in the context of globalisation. The discussion draws on a case study focusing on a Fulfuldephone servile group from Northern Benin called the Gando. Since pre-colonial times, their servile status ascribed by birth...

Tapping the Brake for Entry, Descent, and Landing

Science.gov (United States)

Gnoffo, Peter A.; Thompson, Kyle; Korzun, Ashley

2016-01-01

A matrix of simulations of hypersonic flow over blunt entry vehicles with steady and pulsing retropropulsion jets is presented. Retropropulsion in the supersonic domain is primarily designed to reduce vehicle velocity directly with thrust. Retropropulsion in the hypersonic domain may enable significant pressure recovery through unsteady, oblique shocks while providing a buffer of reactant gases with relatively low total temperature. Improved pressure recovery, a function of Mach number squared and oblique shock angle, could potentially serve to increase aerodynamic drag in this domain. Pulsing jets are studied to include an additional degree of freedom to search for resonances in an already unsteady flow domain with an objective to maximize the time-averaged drag coefficient. In this paradigm, small jets with minimal footprints of the nozzle exit on the vehicle forebody may be capable of delivering the requisite perturbations to the flow. Simulations are executed assuming inviscid, symmetric flow of a perfect gas to enable a rapid assessment of the parameter space (nozzle geometry, plenum conditions, jet pulse frequency). The pulsed-jet configuration produces moderately larger drag than the constant jet configuration but smaller drag than the jet-off case in this preliminary examination of a single design point. The fundamentals of a new algorithm for this challenging application with time dependent, interacting discontinuities using the feature detection capabilities of Walsh functions are introduced.

On Scalable Deep Learning and Parallelizing Gradient Descent

CERN Document Server

AUTHOR|(CDS)2129036; Möckel, Rico; Baranowski, Zbigniew; Canali, Luca

Speeding up gradient based methods has been a subject of interest over the past years with many practical applications, especially with respect to Deep Learning. Despite the fact that many optimizations have been done on a hardware level, the convergence rate of very large models remains problematic. Therefore, data parallel methods next to mini-batch parallelism have been suggested to further decrease the training time of parameterized models using gradient based methods. Nevertheless, asynchronous optimization was considered too unstable for practical purposes due to a lacking understanding of the underlying mechanisms. Recently, a theoretical contribution has been made which defines asynchronous optimization in terms of (implicit) momentum due to the presence of a queuing model of gradients based on past parameterizations. This thesis mainly builds upon this work to construct a better understanding why asynchronous optimization shows proportionally more divergent behavior when the number of parallel worker...

The descent into glass formation in polymer fluids.

Science.gov (United States)

Freed, Karl F

2011-03-15

Glassy materials have been fundamental to technology since the dawn of civilization and remain so to this day: novel glassy systems are currently being developed for applications in energy storage, electronics, food, drugs, and more. Glass-forming fluids exhibit a universal set of transitions beginning at temperatures often in excess of twice the glass transition temperature T(g) and extending down to T(g), below which relaxation becomes so slow that systems no longer equilibrate on experimental time scales. Despite the technological importance of glasses, no prior theory explains this universal behavior nor describes the huge variations in the properties of glass-forming fluids that result from differences in molecular structure. Not surprisingly, the glass transition is currently regarded by many as the deepest unsolved problem in solid state theory. In this Account, we describe our recently developed theory of glass formation in polymer fluids. Our theory explains the origin of four universal characteristic temperatures of glass formation and their dependence on monomer-monomer van der Waals energies, conformational energies, and pressure and, perhaps most importantly, on molecular details, such as monomer structure, molecular weight, size of side groups, and so forth. The theory also provides a molecular explanation for fragility, a parameter that quantifies the rate of change with temperature of the viscosity and other dynamic mechanical properties at T(g). The fragility reflects the fluid's thermal sensitivity and determines the manner in which glass-formers can be processed, such as by extrusion, casting, or inkjet spotting. Specifically, the theory describes the change in thermodynamic properties and fragility of polymer glasses with variations in the monomer structure, the rigidity of the backbone and side groups, the cohesive energy, and so forth. The dependence of the structural relaxation time at lower temperatures emerges from the theory as the Vogel-Fulcher equation, whereas pressure and concentration analogs of the Vogel-Fulcher expression follow naturally from the theory with no additional assumptions. The computed dependence of T(g) and fragility on the length of the side group in poly(α-olefins) agrees quite well with observed trends, demonstrating that the theory can be utilized, for instance, to guide the tailoring of T(g) and the fragility of glass-forming polymer fluids in the fabrication of new materials. Our calculations also elucidate the molecular characteristics of small-molecule diluents that promote antiplasticization, a lowering of T(g) and a toughening of the material. © 2011 American Chemical Society

Pedestrian ascent and descent fundamental diagram on stairway

Science.gov (United States)

Chen, Juan; Lo, S. M.; Ma, Jian

2017-08-01

Due to the interaction among individuals, pedestrian walking speeds in relatively dense crowds when descending and ascending stairs may present different features from a single pedestrian moving freely. Thus, to obtain a large range of densities, a series of single-file pedestrian movement experiments under laboratory conditions were performed. The trends of the fundamental diagram in a wide pedestrian density range for staircase movement are captured. Detailed features of pedestrian speed with the increase of pedestrian density, headway, and the influence of pedestrians’ lateral sway are further discussed. It is found that with the increase of pedestrian density, the speed decrease rate varies. Meanwhile, the decrease of headway, leads to two speed regimes, i.e. free movement and linear constrained movement. We show that pedestrian speed can be described by counting the number of steps separating pedestrians in longitudinal direction. These enrichments can benefit pedestrian modelling and improve the evaluation of the evacuation performance of a staircase.

Glideslope Descent-Rate Cuing to Aid Carrier Landings

Science.gov (United States)

1980-10-01

provided a sufficiently precise indication ofdescent rate close to the ship. Sensitivity of the arrows was set at alevel that during pretesting...Washington, D.C. 20036 Alexancria, Virginia 22314 American Psychological Assoc. 1 Human Factors Society 2 Psyc. INFO Document Control Unit Attn...Research (Code 458) Behavioral & Social Sciences Psychological Sciences Division 5001 Eisenhower Avenue 800 N. Quincy Street Alexandria, Virginia 22333

Educational health disparities in hypertension and diabetes mellitus among African descent populations in the Caribbean and the USA: a comparative analysis from the Spanish town cohort (Jamaica) and the Jackson heart study (USA).

Science.gov (United States)

Bidulescu, Aurelian; Ferguson, Trevor S; Hambleton, Ian; Younger-Coleman, Novie; Francis, Damian; Bennett, Nadia; Griswold, Michael; Fox, Ervin; MacLeish, Marlene; Wilks, Rainford; Harris, E Nigel; Sullivan, Louis W

2017-02-14

Studies have suggested that social inequalities in chronic disease outcomes differ between industrialized and developing countries, but few have directly compared these effects. We explored inequalities in hypertension and diabetes prevalence between African-descent populations with different levels of educational attainment in Jamaica and in the United States of America (USA), comparing disparities within each location, and between countries. We analyzed baseline data from the Jackson Heart Study (JHS) in the USA and Spanish Town Cohort (STC) in Jamaica. Participants reported their highest level of educational attainment, which was categorized as 'less than high school' (HS). Educational disparities in the prevalence of hypertension and diabetes were examined using prevalence ratios (PR), controlling for age, sex and body mass index (BMI). Analyses included 7248 participants, 2382 from STC and 4866 from JHS, with mean age of 47 and 54 years, respectively (p hypertension and diabetes was significantly higher in the JHS compared to STC, 62% vs. 25% (p hypertension and diabetes in both studies; however, after accounting for confounding or interaction by age, sex and BMI these effects were attenuated. For hypertension, after adjusting for age and BMI, a significant education disparity was found only for women in JHS, with PR of 1.10 (95% CI 1.04-1.16) for  HS and 1.07 (95% CI 1.01-1.13) for HS vs > HS. For diabetes; when considering age-group and sex specific estimates adjusted for BMI, among men: significant associations were seen only in the 45-59 years age-group in JHS with PR 1.84 (95% CI 1.16-2.91) for  HS. Among women, significant PR comparing  HS was seen for all three age-groups for JHS, but not in STC; PR were 3.95 (95% CI 1.94-8.05), 1.53 (95% CI 1.10-2.11) and 1.32 (95% CI 1.06-1.64) for 25-44, 45-59 and 60-74 age-groups, respectively. In Jamaica, educational disparities were largely explained by age, sex and BMI, while in the USA these

Role of perineal ultrasonography in postoperative evaluation of patients with stress incontinence

International Nuclear Information System (INIS)

Ko, Seog Wan; Jeong, Yong Yeon; Kang, Heoung Keun; Chung, Tae Woong; Seo, Jeong Jin; Park, Jin Gyoon; Kwon, Dong Deuk

2001-01-01

To evaluate the effectiveness of perineal ultrasonography in the evaluation of female stress incontinence after surgical management. Perineal ultrasonography was performed in 19 patients who were surgically treated for stress incontinence and this was performed in erect position. Nineteen patients were divided into two groups, group A for 11 patients with resolved incontinent after surgery and group B for 8 patients with persistent incontinence even after surgery. Using a sagittal scan of the anterior pelvis at the level of the symphysis pubis, the posterior urethrovesical angel (PUVA) and descent of the bladder neck were measured at rest and during stress (Valsalva maneuver), and these measured values obtained before and after surgery were compared between two groups, group A and B. Postoperative PUVA and descent of the bladder neck were decreased when compared with preoperative values measured at rest and during stress in both groups. There was a statistically significant difference in the postoperative PUVA between two groups (p< 0.05). The mean increment of PUVA during stress after surgery was 6.3 ± 3.8. deg in group A and 14.6 ± 6.4. deg in group B, respectively, showing statistically significant difference (p< 0.05). There was also a statistically difference in the mean descent of the bladder neck during stress after surgery between the two groups (p<0.05). The measurement and comparison of PUVA and descent of the bladder neck by perineal ultrasonography before and after surgery in patients with stress incontinence offered useful and objective information in evaluating the effectiveness of surgical management in females stress incontinence, the stress effectiveness in the stress incontinence.

Particle swarm optimization-based automatic parameter selection for deep neural networks and its applications in large-scale and high-dimensional data

Science.gov (United States)

2017-01-01

In this paper, we propose a new automatic hyperparameter selection approach for determining the optimal network configuration (network structure and hyperparameters) for deep neural networks using particle swarm optimization (PSO) in combination with a steepest gradient descent algorithm. In the proposed approach, network configurations were coded as a set of real-number m-dimensional vectors as the individuals of the PSO algorithm in the search procedure. During the search procedure, the PSO algorithm is employed to search for optimal network configurations via the particles moving in a finite search space, and the steepest gradient descent algorithm is used to train the DNN classifier with a few training epochs (to find a local optimal solution) during the population evaluation of PSO. After the optimization scheme, the steepest gradient descent algorithm is performed with more epochs and the final solutions (pbest and gbest) of the PSO algorithm to train a final ensemble model and individual DNN classifiers, respectively. The local search ability of the steepest gradient descent algorithm and the global search capabilities of the PSO algorithm are exploited to determine an optimal solution that is close to the global optimum. We constructed several experiments on hand-written characters and biological activity prediction datasets to show that the DNN classifiers trained by the network configurations expressed by the final solutions of the PSO algorithm, employed to construct an ensemble model and individual classifier, outperform the random approach in terms of the generalization performance. Therefore, the proposed approach can be regarded an alternative tool for automatic network structure and parameter selection for deep neural networks. PMID:29236718

Chern-Simons, Wess-Zumino and other cocycles from Kashiwara-Vergne and associators

Science.gov (United States)

Alekseev, Anton; Naef, Florian; Xu, Xiaomeng; Zhu, Chenchang

2018-03-01

Descent equations play an important role in the theory of characteristic classes and find applications in theoretical physics, e.g., in the Chern-Simons field theory and in the theory of anomalies. The second Chern class (the first Pontrjagin class) is defined as p= where F is the curvature 2-form and is an invariant scalar product on the corresponding Lie algebra g. The descent for p gives rise to an element ω =ω _3+ω _2+ω _1+ω _0 of mixed degree. The 3-form part ω _3 is the Chern-Simons form. The 2-form part ω _2 is known as the Wess-Zumino action in physics. The 1-form component ω _1 is related to the canonical central extension of the loop group LG. In this paper, we give a new interpretation of the low degree components ω _1 and ω _0. Our main tool is the universal differential calculus on free Lie algebras due to Kontsevich. We establish a correspondence between solutions of the first Kashiwara-Vergne equation in Lie theory and universal solutions of the descent equation for the second Chern class p. In more detail, we define a 1-cocycle C which maps automorphisms of the free Lie algebra to one forms. A solution of the Kashiwara-Vergne equation F is mapped to ω _1=C(F). Furthermore, the component ω _0 is related to the associator Φ corresponding to F. It is surprising that while F and Φ satisfy the highly nonlinear twist and pentagon equations, the elements ω _1 and ω _0 solve the linear descent equation.

Knee joint moments during high flexion movements: Timing of peak moments and the effect of safety footwear.

Science.gov (United States)

Chong, Helen C; Tennant, Liana M; Kingston, David C; Acker, Stacey M

2017-03-01

(1) Characterize knee joint moments and peak knee flexion moment timing during kneeling transitions, with the intent of identifying high-risk postures. (2) Determine whether safety footwear worn by kneeling workers (construction workers, tile setters, masons, roofers) alters high flexion kneeling mechanics. Fifteen males performed high flexion kneeling transitions. Kinetics and kinematics were analyzed for differences in ascent and descent in the lead and trail legs. Mean±standard deviation peak external knee adduction and flexion moments during transitions ranged from 1.01±0.31 to 2.04±0.66% body weight times height (BW∗Ht) and from 3.33 to 12.6% BW∗Ht respectively. The lead leg experienced significantly higher adduction moments compared to the trail leg during descent, when work boots were worn (interaction, p=0.005). There was a main effect of leg (higher lead vs. trail) on the internal rotation moment in both descent (p=0.0119) and ascent (p=0.0129) phases. Peak external knee adduction moments during transitions did not exceed those exhibited during level walking, thus increased knee adduction moment magnitude is likely not a main factor in the development of knee OA in occupational kneelers. Additionally, work boots only significantly increased the adduction moment in the lead leg during descent. In cases where one knee is painful, diseased, or injured, the unaffected knee should be used as the lead leg during asymmetric bilateral kneeling. Peak flexion moments occurred at flexion angles above the maximum flexion angle exhibited during walking (approximately 60°), supporting the theory that the loading of atypical surfaces may aid disease development or progression. Copyright © 2016 Elsevier B.V. All rights reserved.

A time-based concept for terminal-area traffic management

Science.gov (United States)

Erzberger, Heinz; Tobias, Leonard

1986-01-01

An automated air-traffic-management concept that has the potential for significantly increasing the efficiency of traffic flows in high-density terminal areas is discussed. The concept's implementation depends on techniques for controlling the landing time of all aircraft entering the terminal area, both those that are equipped with on-board four-dimensional (4D) guidance systems as well as those aircraft types that are conventionally equipped. The two major ground-based elements of the system are a scheduler which assigns conflict-free landing times and a profile descent advisor. Landing time provided by the scheduler is uplinked to equipped aircraft and translated into the appropriate 4D trajectory by the-board flight-management system. The controller issues descent advisories to unequipped aircraft to help them achieve the assigned landing times. Air traffic control simulations have established that the concept provides an efficient method for controlling various mixes of 4D-equipped and unequipped, as well as low- and high-performance, aircraft. Piloted simulations of profiles flown with the aid of advisories have verified the ability to meet specified descent times with prescribed accuracy.

Noninvasive embryo assessment technique based on buoyancy and its association with embryo survival after cryopreservation.

Science.gov (United States)

Wessels, Cara; Penrose, Lindsay; Ahmad, Khaliq; Prien, Samuel

2017-11-01

Embryo cryopreservation offers many benefits by allowing genetic preservation, genetic screening, cost reduction, global embryo transport and single embryo transfer. However, freezing of embryos decreases embryo viability, as intracellular ice crystal formation often damages embryos. Success rates of frozen embryo transfer are expected to be 15-20% less than fresh embryo transfer. We have developed a noninvasive embryo assessment technique (NEAT) which enables us to predict embryo viability based on buoyancy. The purpose of this research was twofold. First was to determine if a NEAT, through a specific gravity device can detect embryo survival of cryopreservation. Second, it was to relate embryo buoyancy to embryo viability for establishing pregnancies in sheep. Blastocysts descent times were measured on one-hundred sixty-nine mice blastocysts before cryopreservation, according to standard protocol and post-thawing blastocysts descent times were measured again. There was a significant difference in blastocyst post-thaw descent times with NEAT in those blastocysts which demonstrated viability from those that did not (P embryos. Further studies on a larger scale commercial setting will evaluate the efficacy of NEAT. Copyright © 2017 Elsevier Inc. All rights reserved.

Influence of gamma rays irradiation to chlorphyriphos insecticides residues in grapes (vitis vinifera L.)

International Nuclear Information System (INIS)

Chairul, S.M.

2012-01-01

Simulation methods to determination of chlorphyriphos insecticides residue in grapes cause effect gamma rays, was done. Fruits of grapes soaked with chlorpyriphos insecticide solution high level concentrated (100 ppm; 200 ppm; and 300 ppm) for 3 (three minutes). The treatment of the sample was direct of extraction after soaks; extract after storage for one week after soak, and extract after soak after storage for one week after irradiation at 0.5 kGy; 1.0 kGy; and 1.5 kGy dose. Extraction methods using ethyl acetate solvent, and using sodium sulphate as to dryed water level in grapes, and then extractan was injected to chromatography gas use electron capture detector. The result indicated that occur of descent of chlorpyrifos residues from eachs soaked consequence at storage for one week was amount 7,55; 8,42; and 18,88% respectively, while of consequence irradiation of gamma ray at 0,5 kGy doses, will be descent of chlorpyrifos residues in amount 13,90; 19,16; and 52,79% respectively, and at 1,0 kGy doses irradiation will be descent in amount 34,45; 36,15 and 49,79%, respectively. (author)

Detection and mapping of polar stratospheric clouds using limb scattering observations

Directory of Open Access Journals (Sweden)

C. von Savigny

2005-01-01

Full Text Available Satellite-based measurements of Visible/NIR limb-scattered solar radiation are well suited for the detection and mapping of polar stratospheric clouds (PSCs. This publication describes a method to detect PCSs from limb scattering observations with the Scanning Imaging Absorption spectroMeter for Atmospheric CartograpHY (SCIAMACHY on the European Space Agency's Envisat spacecraft. The method is based on a color-index approach and requires a priori knowledge of the stratospheric background aerosol loading in order to avoid false PSC identifications by stratospheric background aerosol. The method is applied to a sample data set including the 2003 PSC season in the Southern Hemisphere. The PSCs are correlated with coincident UKMO model temperature data, and with very few exceptions, the detected PSCs occur at temperatures below 195–198 K. Monthly averaged PSC descent rates are about 1.5 km/month for the −50° S to −75° S latitude range and assume a maximum between August and September with a value of about 2.5 km/month. The main cause of the PSC descent is the slow descent of the lower stratospheric temperature minimum.

An Overview of Propulsion Concept Studies and Risk Reduction Activities for Robotic Lunar Landers

Science.gov (United States)

Trinh, Huu P.; Story, George; Burnside, Chris; Kudlach, Al

2010-01-01

In support of designing robotic lunar lander concepts, the propulsion team at NASA Marshall Space Flight Center (MSFC) and the Johns Hopkins University Applied Physics Laboratory (APL), with participation from industry, conducted a series of trade studies on propulsion concepts with an emphasis on light-weight, advanced technology components. The results suggest a high-pressure propulsion system may offer some benefits in weight savings and system packaging. As part of the propulsion system, a solid rocket motor was selected to provide a large impulse to reduce the spacecraft s velocity prior to the lunar descent. In parallel to this study effort, the team also began technology risk reduction testing on a high thrust-to-weight descent thruster and a high-pressure regulator. A series of hot-fire tests was completed on the descent thruster in vacuum conditions at NASA White Sands Test Facility (WSTF) in New Mexico in 2009. Preparations for a hot-fire test series on the attitude control thruster at WSTF and for pressure regulator testing are now underway. This paper will provide an overview of the concept trade study results along with insight into the risk mitigation activities conducted to date.

“Uncovering the Kink Celebrating my Black Identity: Perceptions on Afro-Costa Ricans Natural Hair”

Directory of Open Access Journals (Sweden)

Carmen Hutchinson Miller

2016-05-01

Full Text Available It is no secret the racism within the Costa Rican society especially against people of African descent. While this racism is manifested in mostly overt ways it is nonetheless present, and continues to affect people of African descent in a myriad of ways including how they feel about their natural hair. From a very early age Afro-Costa Rican children learn to look down on their natural kink reinforced verbally and through images designed for them to hide, and dislike what is naturally theirs. As a result many embraced synthetic, and other ethnic group’s natural hair, preferring to pay any amount of money besides undergoing significant hair, and scalp ill-treatment all with the objective of hiding the natural kink. The main objective of this paper is to make visible the perceptions of Afro-Costa Ricans natural hair by both Afro, and mestizo ethnic groups, and enquire about some of the effects on people of African descent in Costa Rica. The exploratory research collected data from four focus groups of teenage mestizos, 20th century newspaper, one workshop, and questionnaires filled only by Afro-Costa Ricans.

Induced Environment Contamination Monitor (IECM), air sampler - Results from the Space Transport System (STS-2) flight

Science.gov (United States)

Peters, P. N.; Hester, H. B.; Bertsch, W.; Mayfield, H.; Zatko, D.

1983-01-01

An investigation involving sampling the rapidly changing environment of the Shuttle cargo bay is considered. Four time-integrated samples and one rapid acquisition sample were collected to determine the types and quantities of contaminants present during ascent and descent of the Shuttle. The sampling times for the various bottles were controlled by valves operated by the Data Acquisition and Control System (DACS) of the IECM. Many of the observed species were found to be common solvents used in cleaning surfaces. When the actual volume sampled is taken into account, the relative mass of organics sampled during descent is about 20 percent less than during ascent.

[Analyses of clinical features and efficacy of sudden deafness with vertigo and dizziness].

Science.gov (United States)

Liu, Bo; Han, Demin; Zhang, Yi; Li, Yongxin; Gong, Shusheng; Chen, Xiuwu; Meng, Xixi; Tang, Junxiang; Xiang, Jie; Jiang, Xuejun; Yang, Ning; Tian, Ying; Hui, Lian; Feng, Shuai

2015-06-01

To investigate the clinical characteristics and the effect of drug treatment for sudden hearing loss with vertigo or dizziness. In a prospective, randomized, single blinded randomized multicenter clinical study, patients with sudden deafness, ranging in age from 18 to 65 years old, with a duration less than 2 weeks, and with no any medical treatments were collected. In accordance with the hearing curve, those patients were divided into four types, i.e., low and intermediate frequency descent type; high frequency descent type; fall flat type; and total deafness type. Each type was treated by four different treatment options, according to the unified design of the random table, and randomly selected one of the options for treatment. The efficacy of the patients with sudden deafness with vertigo and dizziness was analyzed statistically after the follow-up for 4 weeks. SPSS 13.0 software was used to analyze the data. In August 2007 to October 2011, 33 hospitals in the country included 1 024 patients with sudden deafness in line with the inclusion criteria, of whom 296 (28.91%) were accompanied by vertigo/dizziness symptoms, 126 were males and 170 were females, with an average age of (41.2 ± 13.5) years old. types of the different audiometric curves of sudden deafness, the occurrence of complete deafness with vertigo/dizziness was the highest (44.93%), followed by flat down type (25.87%), high frequency descent type (21.28%) and low intermediate frequency descent type (18.54%). After the standard treatment, the vertigo and dizziness symptoms of the sudden deafness patients could disappear, and the hearing in each group was obviously improved. The hearing curative effect on patients accompanied by vertigo/dizziness of low frequency and intermediate frequency descent type was the best, and the total efficiency can reach up to 94.74%, with the cure rate of 68.42%; followed by flat type, in which the total effective rate was 80.76%, with the recovery rate of 22.12%; and

Five Polymorphisms and Breast Cancer Risk: Results from the Breast Cancer Association Consortium

Science.gov (United States)

Gaudet, Mia M.; Milne, Roger L.; Cox, Angela; Camp, Nicola J.; Goode, Ellen L.; Humphreys, Manjeet K.; Dunning, Alison M.; Morrison, Jonathan; Giles, Graham G.; Severi, Gianluca; Baglietto, Laura; English, Dallas R.; Couch, Fergus J.; Olson, Janet E.; Wang, Xianshu; Chang-Claude, Jenny; Flesch-Janys, Dieter; Abbas, Sascha; Salazar, Ramona; Mannermaa, Arto; Kataja, Vesa; Kosma, Veli-Matti; Lindblom, Annika; Margolin, Sara; Heikkinen, Tuomas; Kämpjärvi, Kati; Aaltonen, Kirsimari; Nevanlinna, Heli; Bogdanova, Natalia; Coinac, Irina; Schürmann, Peter; Dörk, Thilo; Bartram, Claus R.; Schmutzler, Rita K.; Tchatchou, Sandrine; Burwinkel, Barbara; Brauch, Hiltrud; Torres, Diana; Hamann, Ute; Justenhoven, Christina; Ribas, Gloria; Arias, José I.; Benitez, Javier; Bojesen, Stig E.; Nordestgaard, Børge G.; Flyger, Henrik L.; Peto, Julian; Fletcher, Olivia; Johnson, Nichola; Silva, Isabel dos Santos; Fasching, Peter A.; Beckmann, Matthias W.; Strick, Reiner; Ekici, Arif B.; Broeks, Annegien; Schmidt, Marjanka K.; van Leeuwen, Flora E.; Van’t Veer, Laura J.; Southey, Melissa C.; Hopper, John L.; Apicella, Carmel; Haiman, Christopher A.; Henderson, Brian E.; Le Marchand, Loic; Kolonel, Laurence N.; Kristensen, Vessela; Alnæs, Grethe Grenaker; Hunter, David J.; Kraft, Peter; Cox, David G.; Hankinson, Susan E.; Seynaeve, Caroline; Vreeswijk, Maaike P.G.; Tollenaar, Rob A.E.M.; Devilee, Peter; Chanock, Stephen; Lissowska, Jolanta; Brinton, Louise; Peplonska, Beata; Czene, Kamila; Hall, Per; Li, Yuqing; Liu, Jianjun; Balasubramanian, Sabapathy; Rafii, Saeed; Reed, Malcolm W.R.; Pooley, Karen A.; Conroy, Don; Baynes, Caroline; Kang, Daehee; Yoo, Keun-Young; Noh, Dong-Young; Ahn, Sei-Hyun; Shen, Chen-Yang; Wang, Hui-Chun; Yu, Jyh-Cherng; Wu, Pei-Ei; Anton-Culver, Hoda; Ziogoas, Argyrios; Egan, Kathleen; Newcomb, Polly; Titus-Ernstoff, Linda; Dietz, Amy Trentham; Sigurdson, Alice J.; Alexander, Bruce H.; Bhatti, Parveen; Allen-Brady, Kristina; Cannon-Albright, Lisa A.; Wong, Jathine; Chenevix-Trench, Georgia; Spurdle, Amanda B.; Beesley, Jonathan; Pharoah, Paul D.P.; Easton, Doug F.; Garcia-Closas, Montserrat

2009-01-01

Previous studies have suggested that minor alleles for ERCC4 rs744154, TNF rs361525, CASP10 rs13010627, PGR rs1042838, and BID rs8190315 may influence breast cancer risk, but the evidence is inconclusive due to their small sample size. These polymorphisms were genotyped in more than 30,000 breast cancer cases and 30,000 controls, primarily of European descent, from 30 studies in the Breast Cancer Association Consortium. We calculated odds ratios (OR) and 95% confidence intervals (95% CI) as a measure of association. We found that the minor alleles for these polymorphisms were not related to invasive breast cancer risk overall in women of European descent: ECCR4 per-allele OR (95% CI) = 0.99 (0.97–1.02), minor allele frequency = 27.5%; TNF 1.00 (0.95–1.06), 5.0%; CASP10 1.02 (0.98–1.07), 6.5%; PGR 1.02 (0.99–1.06), 15.3%; and BID 0.98 (0.86–1.12), 1.7%. However, we observed significant between-study heterogeneity for associations with risk for single-nucleotide polymorphisms (SNP) in CASP10, PGR, and BID. Estimates were imprecise for women of Asian and African descent due to small numbers and lower minor allele frequencies (with the exception of BID SNP). The ORs for each copy of the minor allele were not significantly different by estrogen or progesterone receptor status, nor were any significant interactions found between the polymorphisms and age or family history of breast cancer. In conclusion, our data provide persuasive evidence against an overall association between invasive breast cancer risk and ERCC4 rs744154, TNF rs361525, CASP10 rs13010627, PGR rs1042838, and BID rs8190315 genotypes among women of European descent. PMID:19423537

Asymptotic Parachute Performance Sensitivity

Science.gov (United States)

Way, David W.; Powell, Richard W.; Chen, Allen; Steltzner, Adam D.

2006-01-01

In 2010, the Mars Science Laboratory mission will pioneer the next generation of robotic Entry, Descent, and Landing systems by delivering the largest and most capable rover to date to the surface of Mars. In addition to landing more mass than any other mission to Mars, Mars Science Laboratory will also provide scientists with unprecedented access to regions of Mars that have been previously unreachable. By providing an Entry, Descent, and Landing system capable of landing at altitudes as high as 2 km above the reference gravitational equipotential surface, or areoid, as defined by the Mars Orbiting Laser Altimeter program, Mars Science Laboratory will demonstrate sufficient performance to land on 83% of the planet s surface. By contrast, the highest altitude landing to date on Mars has been the Mars Exploration Rover at 1.3 km below the areoid. The coupling of this improved altitude performance with latitude limits as large as 60 degrees off of the equator and a precise delivery to within 10 km of a surface target, will allow the science community to select the Mars Science Laboratory landing site from thousands of scientifically interesting possibilities. In meeting these requirements, Mars Science Laboratory is extending the limits of the Entry, Descent, and Landing technologies qualified by the Mars Viking, Mars Pathfinder, and Mars Exploration Rover missions. Specifically, the drag deceleration provided by a Viking-heritage 16.15 m supersonic Disk-Gap-Band parachute in the thin atmosphere of Mars is insufficient, at the altitudes and ballistic coefficients under consideration by the Mars Science Laboratory project, to maintain necessary altitude performance and timeline margin. This paper defines and discusses the asymptotic parachute performance observed in Monte Carlo simulation and performance analysis and its effect on the Mars Science Laboratory Entry, Descent, and Landing architecture.

Usefulness of perineal ultrasonography after tension-free vaginal tape procedure for stress urinary incontinence

International Nuclear Information System (INIS)

Yoon, Seong Kuk

2005-01-01

To evaluate the usefulness of perineal ultrasonography after a tension-free vaginal tape (TVT) procedure in women with stress urinary incontinence. Thirty-four patients with stress urinary incontinence who underwent the TVT procedure were included in this study. We compared the perineal ultrasonography findings before and after the procedure. The mean age was 49 years (rang: 32-75 years) and the mean follow-up time was 9.5 days (range: 5-19 days). We obtained the entire sagittal image of the bladder neck, urethra, urethrovesical junction and symphysis pubis. The posterior urethrovesical angle (PUVA) and descent of the bladder neck at rest and during stress, and the diameter of proximal urethra at rest were all evaluated. We compared these ultrasonographic changes before and after the procedure. Before the TVT procedure, the PUVA was 134.7 ± 5.9 .deg. at rest and 146.8 ± 8.5 .deg. during stress, and the difference between PUVA at rest and during stress was 12.2 ± 7.3 .deg. . After the TVT procedure, the PUVA significantly decreased to 125.6 ± 7.5 .deg. at rest and 132.5 ± 8.3 .deg. during stress, and the difference also significantly decreased to 7.0 ± 5.0 .deg. (ρ < 0.01). Before the procedure, the descent of the bladder neck was 17 ± 7.0 mm, while the descent significantly decreased to 7.7 ± 4.1 mm after the procedure (ρ < 0.01). Before the procedure, the diameter of the proximal urethra was 5.6 ± 1.4 mm at rest, but the diameter was 5.5 ± 1.1 mm, without significant change, after the procedure. Follow-up perineal ultrasonography after the TVT procedure may be useful for evaluating changes including the PUVA, descent and appearance of the bladder neck

Usefulness of perineal ultrasonography after tension-free vaginal tape procedure for stress urinary incontinence

Energy Technology Data Exchange (ETDEWEB)

Yoon, Seong Kuk [Donga University College of Medicine, Busan (Korea, Republic of)

2005-07-15

To evaluate the usefulness of perineal ultrasonography after a tension-free vaginal tape (TVT) procedure in women with stress urinary incontinence. Thirty-four patients with stress urinary incontinence who underwent the TVT procedure were included in this study. We compared the perineal ultrasonography findings before and after the procedure. The mean age was 49 years (rang: 32-75 years) and the mean follow-up time was 9.5 days (range: 5-19 days). We obtained the entire sagittal image of the bladder neck, urethra, urethrovesical junction and symphysis pubis. The posterior urethrovesical angle (PUVA) and descent of the bladder neck at rest and during stress, and the diameter of proximal urethra at rest were all evaluated. We compared these ultrasonographic changes before and after the procedure. Before the TVT procedure, the PUVA was 134.7 {+-} 5.9 .deg. at rest and 146.8 {+-} 8.5 .deg. during stress, and the difference between PUVA at rest and during stress was 12.2 {+-} 7.3 .deg. . After the TVT procedure, the PUVA significantly decreased to 125.6 {+-} 7.5 .deg. at rest and 132.5 {+-} 8.3 .deg. during stress, and the difference also significantly decreased to 7.0 {+-} 5.0 .deg. ({rho} < 0.01). Before the procedure, the descent of the bladder neck was 17 {+-} 7.0 mm, while the descent significantly decreased to 7.7 {+-} 4.1 mm after the procedure ({rho} < 0.01). Before the procedure, the diameter of the proximal urethra was 5.6 {+-} 1.4 mm at rest, but the diameter was 5.5 {+-} 1.1 mm, without significant change, after the procedure. Follow-up perineal ultrasonography after the TVT procedure may be useful for evaluating changes including the PUVA, descent and appearance of the bladder neck.

Ambulatory measurement of knee motion and physical activity: preliminary evaluation of a smart activity monitor

Directory of Open Access Journals (Sweden)

Malchau Henrik

2006-09-01

Full Text Available Abstract Background There is currently a paucity of devices available for continuous, long-term monitoring of human joint motion. Non-invasive, inexpensive devices capable of recording human activity and joint motion have many applications for medical research. Such a device could be used to quantify range of motion outside the gait laboratory. The purpose of this study was to test the accuracy of the modified Intelligent Device for Energy Expenditure and Activity (IDEEA in measuring knee flexion angles, to detect different physical activities, and to quantify how often healthy subjects use deep knee flexion in the ambulatory setting. Methods We compared Biomotion Laboratory (BML "gold standard" data to simultaneous IDEEA measures of knee motion and gait, step up/down, and stair descent in 5 healthy subjects. In addition, we used a series of choreographed physical activities outside the BML to confirm the IDEEA's ability to accurately measure 7 commonly-performed physical activities. Subjects then continued data collection during ordinary activities outside the gait laboratory. Results Pooled correlations between the BML and IDEEA knee flexion angles were .97 +/- .03 for step up/down, .98 +/- .02 for stair descent, and .98 +/- .01 for gait. In the BML protocol, the IDEEA accurately identified gait, but was less accurate in identifying step up/down and stair descent. During sampling outside the BML, the IDEEA accurately detected walking, running, stair ascent, stair descent, standing, lying, and sitting. On average, subjects flexed their knees >120° for 0.17% of their data collection periods outside the BML. Conclusion The modified IDEEA system is a useful clinical tool for evaluating knee motion and multiple physical activities in the ambulatory setting. These five healthy subjects rarely flexed their knees >120°.

Remember Tolerance Differently

DEFF Research Database (Denmark)

Tønder, Lars

2012-01-01

This essay questions the linear conception of history which often accompanies the way contemporary democratic theory tends to disavow tolerance's discontinuities and remainders. In the spirit of Foucault's genealogy of descent, the idea is to develop a new sense of tolerance's history, not by inv......This essay questions the linear conception of history which often accompanies the way contemporary democratic theory tends to disavow tolerance's discontinuities and remainders. In the spirit of Foucault's genealogy of descent, the idea is to develop a new sense of tolerance's history......, not by invoking a critique external to contemporary democratic theory, but by witnessing the history of tolerance paraliptically, with an eye to what it obscures and yet presupposes....

All God's Chillun Got a Mama and a Papa?

Science.gov (United States)

Hollander, Willard F.

1972-01-01

Describes alternate methods of schematically representing genetic lines of descent, and illustrates the different patterns obtained with random mating, line breeding, parthanogentic males, cloning, and grafting. (AL)

Coupled thermal, structural and vibrational analysis of a hypersonic engine for flight test

Energy Technology Data Exchange (ETDEWEB)

Sook-Ying, Ho [Defence Science and Technology Organisation, SA (Australia); Paull, A. [Queensland Univ., Dept. of Mechanical Engineering (Australia)

2006-07-15

This paper describes a relatively simple and quick method for implementing aerodynamic heating models into a finite element code for non-linear transient thermal-structural and thermal-structural-vibrational analyses of a Mach 10 generic HyShot scram-jet engine. The thermal-structural-vibrational response of the engine was studied for the descent trajectory from 60 to 26 km. Aerodynamic heating fluxes, as a function of spatial position and time for varying trajectory points, were implemented in the transient heat analysis. Additionally, the combined effect of varying dynamic pressure and thermal loads with altitude was considered. This aero-thermal-structural analysis capability was used to assess the temperature distribution, engine geometry distortion and yielding of the structural material due to aerodynamic heating during the descent trajectory, and for optimising the wall thickness, nose radius of leading edge, etc. of the engine intake. A structural vibration analysis was also performed following the aero-thermal-structural analysis to determine the changes in natural frequencies of the structural vibration modes that occur at the various temperatures associated with the descent trajectory. This analysis provides a unique and relatively simple design strategy for predicting and mitigating the thermal-structural-vibrational response of hypersonic engines. (authors)

Elucidating the evolutionary conserved DNA-binding specificities of WRKY transcription factors by molecular dynamics and in vitro binding assays

Science.gov (United States)

Brand, Luise H.; Fischer, Nina M.; Harter, Klaus; Kohlbacher, Oliver; Wanke, Dierk

2013-01-01

WRKY transcription factors constitute a large protein family in plants that is involved in the regulation of developmental processes and responses to biotic or abiotic stimuli. The question arises how stimulus-specific responses are mediated given that the highly conserved WRKY DNA-binding domain (DBD) exclusively recognizes the ‘TTGACY’ W-box consensus. We speculated that the W-box consensus might be more degenerate and yet undetected differences in the W-box consensus of WRKYs of different evolutionary descent exist. The phylogenetic analysis of WRKY DBDs suggests that they evolved from an ancestral group IIc-like WRKY early in the eukaryote lineage. A direct descent of group IIc WRKYs supports a monophyletic origin of all other group II and III WRKYs from group I by loss of an N-terminal DBD. Group I WRKYs are of paraphyletic descent and evolved multiple times independently. By homology modeling, molecular dynamics simulations and in vitro DNA–protein interaction-enzyme-linked immunosorbent assay with AtWRKY50 (IIc), AtWRKY33 (I) and AtWRKY11 (IId) DBDs, we revealed differences in DNA-binding specificities. Our data imply that other components are essentially required besides the W-box-specific binding to DNA to facilitate a stimulus-specific WRKY function. PMID:23975197

Prevalence and Persistence of Misconceptions in Tree Thinking.

Science.gov (United States)

Kummer, Tyler A; Whipple, Clinton J; Jensen, Jamie L

2016-12-01

Darwin described evolution as "descent with modification." Descent, however, is not an explicit focus of most evolution instruction and often leaves deeply held misconceptions to dominate student understanding of common ancestry and species relatedness. Evolutionary trees are ways of visually depicting descent by illustrating the relationships between species and groups of species. The ability to properly interpret and use evolutionary trees has become known as "tree thinking." We used a 20-question assessment to measure misconceptions in tree thinking and compare the proportion of students who hold these misconceptions in an introductory biology course with students in two higher-level courses including a senior level biology course. We found that misconceptions related to reading the graphic ( reading the tips and node counting ) were variably influenced across time with reading the tips decreasing and node counting increasing in prevalence. On the other hand, misconceptions related to the fundamental underpinnings of evolutionary theory ( ladder thinking and similarity equals relatedness ) proved resistant to change during a typical undergraduate study of biology. A possible new misconception relating to the length of the branches in an evolutionary tree is described. Understanding the prevalence and persistence of misconceptions informs educators as to which misconceptions should be targeted in their courses.

Prevalence and Persistence of Misconceptions in Tree Thinking†

Science.gov (United States)

Kummer, Tyler A.; Whipple, Clinton J.; Jensen, Jamie L.

2016-01-01

Darwin described evolution as “descent with modification.” Descent, however, is not an explicit focus of most evolution instruction and often leaves deeply held misconceptions to dominate student understanding of common ancestry and species relatedness. Evolutionary trees are ways of visually depicting descent by illustrating the relationships between species and groups of species. The ability to properly interpret and use evolutionary trees has become known as “tree thinking.” We used a 20-question assessment to measure misconceptions in tree thinking and compare the proportion of students who hold these misconceptions in an introductory biology course with students in two higher-level courses including a senior level biology course. We found that misconceptions related to reading the graphic (reading the tips and node counting) were variably influenced across time with reading the tips decreasing and node counting increasing in prevalence. On the other hand, misconceptions related to the fundamental underpinnings of evolutionary theory (ladder thinking and similarity equals relatedness) proved resistant to change during a typical undergraduate study of biology. A possible new misconception relating to the length of the branches in an evolutionary tree is described. Understanding the prevalence and persistence of misconceptions informs educators as to which misconceptions should be targeted in their courses. PMID:28101265

Prevalence and Persistence of Misconceptions in Tree Thinking

Directory of Open Access Journals (Sweden)

Tyler A. Kummer

2016-12-01

Full Text Available Darwin described evolution as “descent with modification.” Descent, however, is not an explicit focus of most evolution instruction and often leaves deeply held misconceptions to dominate student understanding of common ancestry and species relatedness. Evolutionary trees are ways of visually depicting descent by illustrating the relationships between species and groups of species. The ability to properly interpret and use evolutionary trees has become known as “tree thinking.” We used a 20-question assessment to measure misconceptions in tree thinking and compare the proportion of students who hold these misconceptions in an introductory biology course with students in two higher-level courses including a senior level biology course. We found that misconceptions related to reading the graphic (reading the tips and node counting were variably influenced across time with reading the tips decreasing and node counting increasing in prevalence. On the other hand, misconceptions related to the fundamental underpinnings of evolutionary theory (ladder thinking and similarity equals relatedness proved resistant to change during a typical undergraduate study of biology. A possible new misconception relating to the length of the branches in an evolutionary tree is described. Understanding the prevalence and persistence of misconceptions informs educators as to which misconceptions should be targeted in their courses.

Efficient Sum of Outer Products Dictionary Learning (SOUP-DIL) and Its Application to Inverse Problems.

Science.gov (United States)

Ravishankar, Saiprasad; Nadakuditi, Raj Rao; Fessler, Jeffrey A

2017-12-01

The sparsity of signals in a transform domain or dictionary has been exploited in applications such as compression, denoising and inverse problems. More recently, data-driven adaptation of synthesis dictionaries has shown promise compared to analytical dictionary models. However, dictionary learning problems are typically non-convex and NP-hard, and the usual alternating minimization approaches for these problems are often computationally expensive, with the computations dominated by the NP-hard synthesis sparse coding step. This paper exploits the ideas that drive algorithms such as K-SVD, and investigates in detail efficient methods for aggregate sparsity penalized dictionary learning by first approximating the data with a sum of sparse rank-one matrices (outer products) and then using a block coordinate descent approach to estimate the unknowns. The resulting block coordinate descent algorithms involve efficient closed-form solutions. Furthermore, we consider the problem of dictionary-blind image reconstruction, and propose novel and efficient algorithms for adaptive image reconstruction using block coordinate descent and sum of outer products methodologies. We provide a convergence study of the algorithms for dictionary learning and dictionary-blind image reconstruction. Our numerical experiments show the promising performance and speedups provided by the proposed methods over previous schemes in sparse data representation and compressed sensing-based image reconstruction.

The usefulness of MR defecography in the evaluation of pelvic floor dysfunction: our experience using 3T MRI.

Science.gov (United States)

Al-Najar, Mahasen S; Ghanem, Ahmed F; AlRyalat, Saif Aldeen S; Al-Ryalat, Nosaiba T; Alhajahjeh, Sultan O

2017-09-01

To assess the usefulness of MR defecography in evaluating pelvic floor dysfunction, and to correlate several pelvic organ abnormalities with each other and with patients' symptoms and characteristics. MR defecographic examinations performed in 3T MRI machine of 95 patients (70 females, 25 males; mean age 48) were retrospectively reviewed. Pelvic organ abnormalities from all three compartments were recorded, including the anorectal junction descent, anterior rectocele, and cystocele. These were graded according to the known HMO system in relation to the pubococcygeal line. The correlation between these different abnormalities and their relation to patient symptoms and characteristics were evaluated. Anorectal junction descent and anterior rectocele were most commonly observed, predominantly manifesting in female patients. Both were associated with abnormalities from all compartments. The middle compartment was the least affected, and its abnormality of uterine/vaginal descent tended to occur in association with the anterior compartment abnormality (cystocele). Anismus was low in incidence, and was not associated with other compartments abnormalities. Both enterocele/peritoneocele and intussusception were uncommon. MR defecography is the modality of choice in assessing pelvic floor dysfunction, because it can neatly show various pelvic organ abnormalities from all compartments in a dynamic fashion, which are frequently coexistent. It can even show clinically silent or unsuspected abnormalities which can impact the management of patients.

Altered joint moment strategy during stair walking in diabetes patients with and without peripheral neuropathy.

Science.gov (United States)

Brown, Steven J; Handsaker, Joseph C; Maganaris, Constantinos N; Bowling, Frank L; Boulton, Andrew J M; Reeves, Neil D

2016-05-01

To investigate lower limb biomechanical strategy during stair walking in patients with diabetes and patients with diabetic peripheral neuropathy, a population known to exhibit lower limb muscular weakness. The peak lower limb joint moments of twenty-two patients with diabetic peripheral neuropathy and thirty-nine patients with diabetes and no neuropathy were compared during ascent and descent of a staircase to thirty-two healthy controls. Fifty-nine of the ninety-four participants also performed assessment of their maximum isokinetic ankle and knee joint moment (muscle strength) to assess the level of peak joint moments during the stair task relative to their maximal joint moment-generating capabilities (operating strengths). Both patient groups ascended and descended stairs slower than controls (pperipheral neuropathy were lower (pperipheral neuropathy compared to controls, and lower at knee only in patients without neuropathy. Operating strengths were higher (pneuropathy during stair descent compared to the controls, but not during stair ascent. Patients with diabetic peripheral neuropathy walk slower to alter gait strategy during stair walking and account for lower-limb muscular weakness, but still exhibit heightened operating strengths during stair descent, which may impact upon fatigue and the ability to recover a safe stance following postural instability. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

Optimal Lunar Landing Trajectory Design for Hybrid Engine

Directory of Open Access Journals (Sweden)

Dong-Hyun Cho

2015-01-01

Full Text Available The lunar landing stage is usually divided into two parts: deorbit burn and powered descent phases. The optimal lunar landing problem is likely to be transformed to the trajectory design problem on the powered descent phase by using continuous thrusters. The optimal lunar landing trajectories in general have variety in shape, and the lunar lander frequently increases its altitude at the initial time to obtain enough time to reduce the horizontal velocity. Due to the increment in the altitude, the lunar lander requires more fuel for lunar landing missions. In this work, a hybrid engine for the lunar landing mission is introduced, and an optimal lunar landing strategy for the hybrid engine is suggested. For this approach, it is assumed that the lunar lander retrofired the impulsive thruster to reduce the horizontal velocity rapidly at the initiated time on the powered descent phase. Then, the lunar lander reduced the total velocity and altitude for the lunar landing by using the continuous thruster. In contradistinction to other formal optimal lunar landing problems, the initial horizontal velocity and mass are not fixed at the start time. The initial free optimal control theory is applied, and the optimal initial value and lunar landing trajectory are obtained by simulation studies.

Landslide Occurrence Prediction Using Trainable Cascade Forward Network and Multilayer Perceptron

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Mohammad Subhi Al-batah

2015-01-01

Full Text Available Landslides are one of the dangerous natural phenomena that hinder the development in Penang Island, Malaysia. Therefore, finding the reliable method to predict the occurrence of landslides is still the research of interest. In this paper, two models of artificial neural network, namely, Multilayer Perceptron (MLP and Cascade Forward Neural Network (CFNN, are introduced to predict the landslide hazard map of Penang Island. These two models were tested and compared using eleven machine learning algorithms, that is, Levenberg Marquardt, Broyden Fletcher Goldfarb, Resilient Back Propagation, Scaled Conjugate Gradient, Conjugate Gradient with Beale, Conjugate Gradient with Fletcher Reeves updates, Conjugate Gradient with Polakribiere updates, One Step Secant, Gradient Descent, Gradient Descent with Momentum and Adaptive Learning Rate, and Gradient Descent with Momentum algorithm. Often, the performance of the landslide prediction depends on the input factors beside the prediction method. In this research work, 14 input factors were used. The prediction accuracies of networks were verified using the Area under the Curve method for the Receiver Operating Characteristics. The results indicated that the best prediction accuracy of 82.89% was achieved using the CFNN network with the Levenberg Marquardt learning algorithm for the training data set and 81.62% for the testing data set.

Effect of upright position on tonsillar level in adolescent idiopathic scoliosis

Energy Technology Data Exchange (ETDEWEB)

Lee, Ryan K.L.; Leung, Joyce H.Y.; Chu, Winnie C.W. [The Chinese University of Hong Kong, Department of Imaging and Interventional Radiology, Prince of Wales Hospital, Hong Kong, Shatin (China); Griffith, James F. [The Chinese University of Hong Kong, Department of Imaging and Interventional Radiology, Prince of Wales Hospital, Hong Kong, Shatin (China); The Chinese University of Hong Kong, Prince of Wales Hospital, Faculty of Medicine, Shatin, Hong Kong, SAR (China); Lam, T.P.; Ng, Bobby K.W.; Cheng, Jack C.Y. [The Chinese University of Hong Kong, Department of Orthopedics and Traumatology, Shatin (China)

2015-08-15

The aim of this study was to investigate the effect of an upright position on cerebellar tonsillar level in patients with adolescent idiopathic scoliosis (AIS). Twenty-five patients with clinically diagnosed AIS and 18 normal controls were examined in both supine and upright positions using 0.25T MRI. The position of the inferior cerebellar tonsil tip relative to a reference line connecting the basion to the opisthion (BO line) was measured in millimetres. None of the 18 normal control subjects had cerebellar tonsillar descent below the BO line in either supine or the upright position. Forty-eight percent of AIS patients had tonsillar descent in the upright position, compared to 28 % in the supine position. In the upright position, cerebellar tonsillar position was lower in AIS patients than in normal subjects (mean -0.7 ± 1.5 vs. +2.1 ± 1.7, p < 0.00001). AIS patients also had a large degree of tonsillar excursion between upright and supine positions compared to normal subjects (mean -1.9 ± 2.3 vs. -0.1 ± 0.2, p < 0.00001). When considering the theoretical likelihood that a low tonsillar position may affect spinal cord function, one should bear in mind that tonsillar descent in AIS is significantly greater in the upright position. (orig.)

U-tube steam generator empirical model development and validation using neural networks

International Nuclear Information System (INIS)

Parlos, A.G.; Chong, K.T.; Atiya, A.

1992-01-01

Empirical modeling techniques that use model structures motivated from neural networks research have proven effective in identifying complex process dynamics. A recurrent multilayer perception (RMLP) network was developed as a nonlinear state-space model structure along with a static learning algorithm for estimating the parameter associated with it. The methods developed were demonstrated by identifying two submodels of a U-tube steam generator (UTSG), each valid around an operating power level. A significant drawback of this approach is the long off-line training times required for the development of even a simplified model of a UTSG. Subsequently, a dynamic gradient descent-based learning algorithm was developed as an accelerated alternative to train an RMLP network for use in empirical modeling of power plants. The two main advantages of this learning algorithm are its ability to consider past error gradient information for future use and the two forward passes associated with its implementation. The enhanced learning capabilities provided by the dynamic gradient descent-based learning algorithm were demonstrated via the case study of a simple steam boiler power plant. In this paper, the dynamic gradient descent-based learning algorithm is used for the development and validation of a complete UTSG empirical model

RELASI BAHASA ARAB DENGAN STRATA SOSIAL MASYARAKAT DAN IMPLIKASINYA TERHADAP KEHIDUPAN SOSIAL, EKONOMI, POLITIK DAN AGAMA (Kajian Sosiolinguistik Pada Masyarakat Tutur Arab Keturunan di Kelurahan Kauman Pekalongan Timur

Directory of Open Access Journals (Sweden)

Muhandis *

2014-03-01

Full Text Available This study is categorized as sociolinguistic studies and used language variation theory based on social ranks -- they are: Akrolek, Basilek, Vulgar, Kolokial -- and interactional theory which is a process of interaction that build, maintain, and change certain habits in language and symbols. Listening, speaking, and Noting were used to collect data. unified and apportion analysis method were used to analyze data. The results were: (1 the existence of social rank within the Arab community in Kauman descent was: (a Cleric group. They were entitled Al-Jufri, Al- Hadad, Al-Ethiopia, Yahya, Shihab, Bawazier and so forth; (b Masayikh group. They were fam Bafadhal, Bahomaid, Baraja, Baharmi (Baharmus, Bawazir, Basyu'aibn, Bamozaham, Ba'abad, bin Khatib, Bin Zabdah, Basalamah; and (c Ghabili group. Those who holds Bashir, Baswedan, Sungkar, Abud, Alkatiri, Badjubier, Bafadhal, and so forth. The existence of regional variations of low and high diversity of languages based on social strata, for example قهار Gahar (angry, حريم Harim (wife, Sir سر (the streets is a slang vocabulary that includes a low range of languages. If they were categorized in the high language using word غضبان, قرينة , and .أمشى The mention of the word pilgrims for Arabs descent, call ahlul wathan for the Javanese and Chinese descent Baodeh for socially showed no difference in social status between the Javanese and Arab descent on one side, and The Chinese descent on the other side. Regional variations of low and high diversity of languages based on their economic status, usually rich people are often invoked as 'Royyes' ( ريس which has the meaning of the aristocracy, including the diversity of languages is low while the high diversity of languages is صاحب الجلالة . Low variation in the range of political language is the word Haromi ( حرمى which is Arabic kolokial have meaning 'thief' or 'Corruptor' high variety of Arabic word 'Corruptor

Hypersonic Inflatable Aerodynamic Decelerator (HIAD)

Data.gov (United States)

National Aeronautics and Space Administration — Develop an entry and descent technology to enhance and enable robotic and scientific missions to destinations with atmospheres.The Hypersonic Inflatable Aerodynamic...

Mars Molniya Orbit Atmospheric Resource Mining

Data.gov (United States)

National Aeronautics and Space Administration — Mars planetary surface access is one of NASA's biggest technical challenges involving advanced entry, descent, and landing (EDL) technologies and methods. This NASA...

Steepest descent method for set-valued locally accretive mappings

International Nuclear Information System (INIS)

Chidume, C.E.

1993-05-01

Let E be a real q-uniformly smooth Banach space. Suppose T is a set-valued locally strongly accretive map with open domain D(T) in E and that 0 is an element of Tx has a solution x* in D(T). Then there exists a neighbourhood B in D(T) of x* and a real number r 1 >0 such that for any r>r 1 and some real sequence {c n }, any initial guess x 1 is an element of B and any single-valued selection T 0 of T, the sequence {x n } generated from x 1 by x n+1 =x n -c n T 0 x n , n≥1, remains in D(T) and converges strongly to x* with ||x n -x*|| O(n -(q-1)/ q). A related result deals with iterative approximation of a solution of the equation f is an element of x+Ax when A is a locally accretive map. Our theorems generalize important known results and resolve a problem of interest. (author). 39 refs

Developing precision medicine for people of East Asian descent.

Science.gov (United States)

McAllister, Stacy L; Sun, Katherine; Gross, Eric R

2016-11-11

The goal of precision medicine is to separate patient populations into groups to ultimately provide customized care tailored to patients. In terms of precision medicine, ~540 million people in the world have a genetic variant of the aldehyde dehydrogenase 2 (ALDH2) enzyme causing a flushing response and tachycardia after alcohol consumption. The genetic variant is identified as ALDH2*2 and originates from East Asian descendants of the Han Chinese. The variant is particularly important to consider when discussing lifestyle choices with patients in terms of risk for developing specific diseases, preventative screening, and selection of medications for treatment. Here we provide examples why patients with an ALDH2*2 variant need more individualized medical management which is becoming a more standard practice in the precision medicine era.

Visually Guided Step Descent in Children with Williams Syndrome

Science.gov (United States)

Cowie, Dorothy; Braddick, Oliver; Atkinson, Janette

2012-01-01

Individuals with Williams syndrome (WS) have impairments in visuospatial tasks and in manual visuomotor control, consistent with parietal and cerebellar abnormalities. Here we examined whether individuals with WS also have difficulties in visually controlling whole-body movements. We investigated visual control of stepping down at a change of…

Screening for homozygosity by descent in families with autosomal ...

Indian Academy of Sciences (India)

Unknown

gressive, and by adulthood constriction and gradual loss ... noids, (d) transcription factors important for photorece- ptors, (e) .... Unconventional myosin present in photoreceptors and hair cells of ... Functions in isomerization of vitamin A in RPE.

Improved Rhenium Thrust Chambers for In-Space Propulsion, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — Radiation-cooled, bipropellant thrust chambers are being considered for the ascent/descent engines and reaction control systems for NASA missions such as Mars Sample...

Afro-Latinos in Latin America and Considerations for U.S. Policy

National Research Council Canada - National Science Library

Ribando, Clare M

2007-01-01

.... In recent years, people of African descent in the Spanish- and Portuguese-speaking nations of Latin America - also known as "Afro-Latinos" have been pushing for increased rights and representation...

Afro-Latinos in Latin America and Considerations for U.S. Policy

National Research Council Canada - National Science Library

Seelke, Clare R

2008-01-01

.... In recent years, people of African descent in the Spanish- and Portuguese-speaking nations of Latin America - also known as "Afro-Latinos" - have been pushing for increased rights and representation...

The teacher taught? What Charles Darwin owed to John Lubbock

Science.gov (United States)

Pearn, Alison

2014-01-01

The period around the publication of John Lubbock's Origin of civilisation in 1870 and Charles Darwin's Descent of man and selection in relation to sex the following year is key to a re-evaluation of the relationship between the two men, usually characterized as that of pupil and master. It is in the making of Descent that Lubbock's role as a scientific collaborator is most easily discerned, a role best understood within the social and political context of the time. Lubbock made Darwin—both the man and his science—acceptable and respectable. Less obvious is Darwin's conscious cultivation of Lubbock's patronage in both his private and public life, and Lubbock's equally conscious bestowal, culminating in his role in Darwin's burial in Westminster Abbey.

Hills and valleys: Understanding the under-eye

Directory of Open Access Journals (Sweden)

Milind N Naik

2016-01-01

Full Text Available Soft tissue deflation and descent have long been implicated in the pathogenesis of facial aging. In the periorbital area, the upper orbital region is thought to change by descent of the eyebrow, as well as deflation of brow fat. While the understanding of the aging changes in the upper eyelid region are relatively simple, the lower eyelid poses a myriad of aging changes, each demanding a specific management plan. These can be best described in terms of elevations, or 'Hills' and hollows, or 'Valleys'. This article simplifies the understanding of the lower eyelid in the light of anatomical knowledge, and available literature. It forms a basis of easy diagnosis and treatment of the soft tissue changes in the lower eyelid and malar region.

76 FR 11929 - Irish-American Heritage Month, 2011

Science.gov (United States)

2011-03-03

... life in a new Nation, these intrepid immigrants built strong communities and helped forge our country's... the American story. Through hard work, perseverance, and patriotism, women and men of Irish descent...

Technologies to Enable EDL of Smallsat Science and Exploration Payloads

Data.gov (United States)

National Aeronautics and Space Administration — The central objective of this research is to develop technologies for Entry, Descent, and Landing (EDL) of cubesat-sized vehicles. While current efforts tend toward...

76 FR 20831 - Pan American Day and Pan American Week, 2011

Science.gov (United States)

2011-04-13

... myriad ways that men and women of African descent have strengthened our countries and enriched our... interconnected world. Together, we will continue to build on our partnerships of equality and shared...

Hypervelocity Expansion Tube Studies of Blunt Body Aerothermodynamics in CO2

Data.gov (United States)

National Aeronautics and Space Administration — According to Technology Area 09, the Entry, Descent, and Landing Roadmap, "current estimates on the extensibility of the MSL architecture indicate that it is limited...

Thalassemia

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... Mediterranean (Greek, Italian and Middle Eastern), Asian, or African descent. Diagnosis & Tests How is thalassemia diagnosed? If your doctor thinks you or your child might have thalassemia, he’ll do a physical ...

14 CFR 121.419 - Pilots and flight engineers: Initial, transition, and upgrade ground training.

Science.gov (United States)

2010-01-01

... necessary to ensure his competence. (2) For each airplane type— (i) A general description; (ii) Performance...) Normal and emergency communication procedures; (vii) Visual cues prior to and during descent below DA/DH...

Pivotal role of the muscle-contraction pathway in cryptorchidism and evidence for genomic connections with cardiomyopathy pathways in RASopathies

KAUST Repository

Cannistraci, Carlo; Ogorevc, Jernej; Zorc, Minja; Ravasi, Timothy; Dovc, Peter; Kunej, Tanja

2013-01-01

genetic factors and molecular pathways underlying testis descent. Methods. Literature mining was performed to collect genomic loci associated with cryptorchidism in seven mammalian species. Information regarding the collected candidate genes was stored

Locomotion mode identification for lower limbs using neuromuscular and joint kinematic signals.

Science.gov (United States)

Afzal, Taimoor; White, Gannon; Wright, Andrew B; Iqbal, Kamran

2014-01-01

Recent development in lower limb prosthetics has seen an emergence of powered prosthesis that have the capability to operate in different locomotion modes. However, these devices cannot transition seamlessly between modes such as level walking, stair ascent and descent and up slope and down slope walking. They require some form of user input that defines the human intent. The purpose of this study was to develop a locomotion mode detection system and evaluate its performance for different sensor configurations and to study the effect of locomotion mode detection with and without electromyography (EMG) signals while using kinematic data from hip joint of non-dominant/impaired limb and an accelerometer. Data was collected from four able bodied subjects that completed two circuits that contained standing, level-walking, ramp ascent and descent and stair ascent and descent. By using only the kinematic data from the hip joint and accelerometer data the system was able to identify the transitions, stance and swing phases with similar performance as compared to using only EMG and accelerometer data. However, significant improvement in classification error was observed when EMG, kinematic and accelerometer data were used together to identify the locomotion modes. The higher recognition rates when using the kinematic data along with EMG shows that the joint kinematics could be beneficial in intent recognition systems of locomotion modes.

Biomechanical compensations of the trunk and lower extremities during stepping tasks after unilateral transtibial amputation.

Science.gov (United States)

Murray, Amanda M; Gaffney, Brecca M; Davidson, Bradley S; Christiansen, Cory L

2017-11-01

Lower extremity movement compensations following transtibial amputation are well-documented and are likely influenced by trunk posture and movement. However, the biomechanical compensations of the trunk and lower extremities, especially during high-demand tasks such as step ascent and descent, remain unclear. Kinematic and kinetic data were collected during step ascent and descent tasks for three groups of individuals: diabetic/transtibial amputation, diabetic, and healthy. An ANCOVA was used to compare peak trunk, hip and knee joint angles and moments in the sagittal and frontal planes between groups. Paired t-tests were used to compare peak joint angles and moments between amputated and intact limbs of the diabetic/transtibial amputation group. During step ascent and descent, the transtibial amputation group exhibited greater trunk forward flexion and lateral flexion compared to the other two groups (Pbiomechanical compensations of the trunk and lower extremities in individuals with dysvascular transtibial amputation, by identifying low back, hip, and knee joint moment patterns unique to transtibial amputation during stepping tasks. In addition, the results suggest that some movement compensations may be confounded by the presence of diabetes and precede limb amputation. The increased and asymmetrical loading patterns identified may predispose individuals with transtibial amputation to the development of secondary pain conditions, such as low back pain or osteoarthritis. Copyright © 2017 Elsevier Ltd. All rights reserved.

An Adaptive Orientation Estimation Method for Magnetic and Inertial Sensors in the Presence of Magnetic Disturbances

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Bingfei Fan

2017-05-01

Full Text Available Magnetic and inertial sensors have been widely used to estimate the orientation of human segments due to their low cost, compact size and light weight. However, the accuracy of the estimated orientation is easily affected by external factors, especially when the sensor is used in an environment with magnetic disturbances. In this paper, we propose an adaptive method to improve the accuracy of orientation estimations in the presence of magnetic disturbances. The method is based on existing gradient descent algorithms, and it is performed prior to sensor fusion algorithms. The proposed method includes stationary state detection and magnetic disturbance severity determination. The stationary state detection makes this method immune to magnetic disturbances in stationary state, while the magnetic disturbance severity determination helps to determine the credibility of magnetometer data under dynamic conditions, so as to mitigate the negative effect of the magnetic disturbances. The proposed method was validated through experiments performed on a customized three-axis instrumented gimbal with known orientations. The error of the proposed method and the original gradient descent algorithms were calculated and compared. Experimental results demonstrate that in stationary state, the proposed method is completely immune to magnetic disturbances, and in dynamic conditions, the error caused by magnetic disturbance is reduced by 51.2% compared with original MIMU gradient descent algorithm.

MODEL JARINGAN SYARAF TIRUAN UNTUK MEMPREDIKSI PARAMETER KUALITAS TOMAT BERDASARKAN PARAMETER WARNA RGB (An artificial neural network model for predicting tomato quality parameters based on color

Directory of Open Access Journals (Sweden)

Rudiati Evi Masithoh

2013-03-01

Full Text Available Artificial neural networks (ANN was used to predict the quality parameters of tomato, i.e. Brix, citric acid, total carotene, and vitamin C. ANN was developed from Red Green Blue (RGB image data of tomatoes measured using a developed computer vision system (CVS. Qualitative analysis of tomato compositions were obtained from laboratory experiments. ANN model was based on a feedforward backpropagation network with different training functions, namely gradient descent (traingd, gradient descent with the resilient backpropagation (trainrp, Broyden, Fletcher, Goldfrab and Shanno (BFGS quasi-Newton (trainbfg, as well as Levenberg Marquardt (trainlm.  The network structure using logsig and linear (purelin activation function at the hidden and output layer, respectively, and using  the trainlm as a training function resulted in the best performance. Correlation coefficient (r of training and validation process were 0.97 - 0.99 and 0.92 - 0.99, whereas the MAE values ​​ranged from 0.01 to 0.23 and 0.03 to 0.59, respectively. Keywords: Artificial neural network, trainlm, tomato, RGB   Jaringan syaraf tiruan (JST digunakan untuk memprediksi parameter kualitas tomat, yaitu Brix, asam sitrat, karoten total, dan vitamin C. JST dikembangkan dari data Red Green Blue (RGB  citra tomat yang diukur menggunakan computer vision system. Data kualitas tomat diperoleh dari analisis di laboratorium. Struktur model JST didasarkan pada jaringan feedforward backpropagation dengan berbagai fungsi pelatihan, yaitu gradient descent (traingd, gradient descent dengan resilient backpropagation (trainrp, Broyden, Fletcher, Goldfrab dan Shanno (BFGS quasi-Newton (trainbfg, serta Levenberg Marquardt (trainlm. Fungsi pelatihan yang terbaik adalah menggunakan trainlm, serta pada struktur jaringan digunakan fungsi aktivasi logsig pada lapisan tersembunyi dan linier (purelin pada lapisan keluaran. dengan 1000 epoch. Nilai koefisien korelasi (r pada tahap pelatihan dan validasi

Intimate partner violence among African American and African Caribbean women: prevalence, risk factors, and the influence of cultural attitudes

Directory of Open Access Journals (Sweden)

Jamila K. Stockman

2014-09-01

Full Text Available Background: Women of African descent are disproportionately affected by intimate partner abuse; yet, limited data exist on whether the prevalence varies for women of African descent in the United States and those in the US territories. Objective: In this multisite study, we estimated lifetime and 2-year prevalence of physical, sexual, and psychological intimate partner abuse (IPA among 1,545 women of African descent in the United States and US Virgin Islands (USVI. We also examined how cultural tolerance of physical and/or sexual intimate partner violence (IPV influences abuse. Design: Between 2009 and 2011, we recruited African American and African Caribbean women aged 18–55 from health clinics in Baltimore, MD, and St. Thomas and St. Croix, USVI, into a comparative case-control study. Screened and enrolled women completed an audio computer-assisted self-interview. Screening-based prevalence of IPA and IPV were stratified by study site and associations between tolerance of IPV and abuse experiences were examined by multivariate logistic regression analysis. Results: Most of the 1,545 screened women were young, of low-income, and in a current intimate relationship. Lifetime prevalence of IPA was 45% in St. Thomas, 38% in St. Croix, and 37% in Baltimore. Lifetime prevalence of IPV was 38% in St. Thomas, 28% in St. Croix, and 30% in Baltimore. Past 2-year prevalence of IPV was 32% in St. Thomas, 22% in St. Croix, and 26% in Baltimore. Risk and protective factors for IPV varied by site. Community and personal acceptance of IPV were independently associated with lifetime IPA in Baltimore and St. Thomas. Conclusions: Variance across sites for risk and protective factors emphasizes cultural considerations in sub-populations of women of African descent when addressing IPA and IPV in given settings. Individual-based interventions should be coupled with community/societal interventions to shape attitudes about use of violence in relationships and to

Airplane Ear

Science.gov (United States)

... your eardrum during ascents and descents. You can purchase these at drugstores, airport gift shops or your ... a man older than age 50, you may experience serious side effects after taking decongestants containing pseudoephedrine ( ...

Preventing and Treating Blood Clots

Science.gov (United States)

... Pacific Islander descent. A condition that is inherited, meaning it is passed down from parent to child ... Enoxaparin (Lovenox) Fondaparinux (Arixtra) Tinzaparin (Innohep) Warfarin (multiple brand names). Some of these drugs are taken orally ...

Oxcarbazepine

Science.gov (United States)

... the doctor if you are of Chinese, Thai, Malaysian, Korean, Indian, or Filipino descent.tell your doctor ... this medication.you should know that your mental health may change in unexpected ways and you may ...

Insulin-like factor 3 levels in cord blood and serum from children: effects of age, postnatal hypothalamic-pituitary-gonadal axis activation, and cryptorchidism

DEFF Research Database (Denmark)

Bay, Katrine; Virtanen, Helena E; Hartung, Stefan

2007-01-01

The Leydig cell hormone insulin-like factor 3 (INSL3) is important for testicular descent. Currently INSL3 levels in cord blood, in serum throughout childhood, and in relation to congenital cryptorchidism are unknown....

For People of African, Mediterranean, or Southeast Asian Heritage: Important Information about Diabetes Blood Tests

Science.gov (United States)

... Urodynamic Testing Virtual Colonoscopy Diabetes Blood Tests for People of African, Mediterranean, or Southeast Asian Descent Introduction ... care. What are some common hemoglobin variants? Most people have only one kind of hemoglobin, called hemoglobin ...

Takayasu arteritis

Science.gov (United States)

... common in people of East Asian, Indian or Mexican descent. However, it is now being seen more ... arteritis is difficult. However, people who have the right treatment can see improvement. It is important to ...

Part I: Houtermans

Science.gov (United States)

Frenkel, Victor Ya.

The following sections are included: * PROFESSOR FRIEDRICH HOUTERMANS: WORKS, LIFE, FATE * Introduction * Beginnings * Göttingen * Berlin * 1933 * London * Impressions of Kharkov * Kharkov: 1935-1937 * Arrests * Last Months in the USSR (From Charlotte Houtermans' Diary) * Descent into the Prisons: 1937-39 * From Desperation to Hope (Continuation of Charlotte Houtermans' Diary) * Fighting for Freedom * Descent into the Prisons: 1939-40 * The Bridge over the River Bug * On the Other Shore * Back in Berlin * The Plutonium Report * "They should Accelerate!" * Back in Kharkov * Kharkov Trace (What Happened at the Session of the Academy of Sciences) * Who are Beck and Godin? * War's End * The Age of the Earth * Friends on Houtermans * Chronology * Appendices (Compiled by the Editor) * Last Diary * Odessa 1930 * Chronological Report of my Life in Russian Prisons * Alexander Weissberg's Letter * After the War

Mars Science Laboratory Heatshield Flight Data Analysis

Science.gov (United States)

Mahzari, Milad; White, Todd

2017-01-01

NASA Mars Science Laboratory (MSL), which landed the Curiosity rover on the surface of Mars on August 5th, 2012, was the largest and heaviest Mars entry vehicle representing a significant advancement in planetary entry, descent and landing capability. Hypersonic flight performance data was collected using MSLs on-board sensors called Mars Entry, Descent and Landing Instrumentation (MEDLI). This talk will give an overview of MSL entry and a description of MEDLI sensors. Observations from flight data will be examined followed by a discussion of analysis efforts to reconstruct surface heating from heatshields in-depth temperature measurements. Finally, a brief overview of MEDLI2 instrumentation, which will fly on NASAs Mars2020 mission, will be presented with a discussion on how lessons learned from MEDLI data affected the design of MEDLI2 instrumentation.

Development of the automatic control rod operation system for JOYO. Verification of automatic control rod operation guide system

International Nuclear Information System (INIS)

Terakado, Tsuguo; Suzuki, Shinya; Kawai, Masashi; Aoki, Hiroshi; Ohkubo, Toshiyuki

1999-10-01

The automatic control rod operation system was developed to control the JOYO reactor power automatically in all operation modes(critical approach, cooling system heat up, power ascent, power descent), development began in 1989. Prior to applying the system, verification tests of the automatic control rod operation guide system was conducted during 32nd duty cycles of JOYO' from Dec. 1997 to Feb. 1998. The automatic control rod operation guide system consists of the control rod operation guide function and the plant operation guide function. The control rod operation guide function provides information on control rod movement and position, while the plant operation guide function provide guidance for plant operations corresponding to reactor power changes(power ascent or power descent). Control rod insertion or withdrawing are predicted by fuzzy algorithms. (J.P.N.)

Comparative study of dental cephalometric patterns of Japanese-Brazilian, Caucasian and Mongoloid patients

Directory of Open Access Journals (Sweden)

Renata Sathler

2014-08-01

Full Text Available INTRODUCTION: The objective of this study was to identify the patterns of dental variables of adolescent Japanese-Brazilian descents with normal occlusion, and also to compare them with a similar Caucasian and Mongoloid sample. METHODS: Lateral cephalometric radiographs were used to compare the groups: Caucasian (n = 40, Japanese-Brazilian (n = 32 and Mongoloid (n = 33. The statistical tests used were one-way ANOVA and ANCOVA. The cephalometric measurements used followed the analyses of Steiner, Tweed and McNamara Jr. RESULTS: Statistical differences (P < 0.05 indicated a smaller interincisal angle and overbite for the Japanese-Brazilian sample, when compared to the Caucasian sample, although with similar values to the Mongoloid group. CONCLUSION: The dental patterns found for the Japanese-Brazilian descents were, in general, more similar to those of the Mongoloid sample.

Magnetotelluric inversion via reverse time migration algorithm of seismic data

International Nuclear Information System (INIS)

Ha, Taeyoung; Shin, Changsoo

2007-01-01

We propose a new algorithm for two-dimensional magnetotelluric (MT) inversion. Our algorithm is an MT inversion based on the steepest descent method, borrowed from the backpropagation technique of seismic inversion or reverse time migration, introduced in the middle 1980s by Lailly and Tarantola. The steepest descent direction can be calculated efficiently by using the symmetry of numerical Green's function derived from a mixed finite element method proposed by Nedelec for Maxwell's equation, without calculating the Jacobian matrix explicitly. We construct three different objective functions by taking the logarithm of the complex apparent resistivity as introduced in the recent waveform inversion algorithm by Shin and Min. These objective functions can be naturally separated into amplitude inversion, phase inversion and simultaneous inversion. We demonstrate our algorithm by showing three inversion results for synthetic data

An application of results by Hardy, Ramanujan and Karamata to Ackermannian functions

Directory of Open Access Journals (Sweden)

Andreas Weiermann

2003-06-01

Full Text Available The Ackermann function is a fascinating and well studied paradigm for a function which eventually dominates all primitive recursive functions. By a classical result from the theory of recursive functions it is known that the Ackermann function can be defined by an unnested or descent recursion along the segment of ordinals below ω ω (or equivalently along the order type of the polynomials under eventual domination. In this article we give a fine structure analysis of such a Ackermann type descent recursion in the case that the ordinals below ω ω are represented via a Hardy Ramanujan style coding. This paper combines number-theoretic results by Hardy and Ramanujan, Karamata's celebrated Tauberian theorem and techniques from the theory of computability in a perhaps surprising way.

Adaptive filtering primer with Matlab

CERN Document Server

Poularikas, Alexander D

2006-01-01

INTRODUCTIONSignal ProcessingAn ExampleOutline of the TextDISCRETE-TIME SIGNAL PROCESSINGDiscrete Time SignalsTransform-Domain Representation of Discrete-Time SignalsThe Z-TransformDiscrete-Time SystemsProblemsHints-Solutions-SuggestionsRANDOM VARIABLES, SEQUENCES, AND STOCHASTIC PROCESSESRandom Signals and DistributionsAveragesStationary ProcessesSpecial Random Signals and Probability Density FunctionsWiener-Khinchin RelationsFiltering Random ProcessesSpecial Types of Random ProcessesNonparametric Spectra EstimationParametric Methods of power Spectral EstimationProblemsHints-Solutions-SuggestionsWIENER FILTERSThe Mean-Square ErrorThe FIR Wiener FilterThe Wiener SolutionWiener Filtering ExamplesProblemsHints-Solutions-SuggestionsEIGENVALUES OF RX - PROPERTIES OF THE ERROR SURFACEThe Eigenvalues of the Correlation MatrixGeometrical Properties of the Error SurfaceProblemsHints-Solutions-SuggestionsNEWTON AND STEEPEST-DESCENT METHODOne-Dimensional Gradient Search MethodSteepest-Descent AlgorithmProblemsHints-Sol...