5,791 research outputs found
Interviewer Attitudes about the Mentally Ill
Interviewer attitudes and expectations about respondents are known to influence data quality. When respondents are from deviant groups, such as the mentally ill, special problems could develop. Questionnaires were completed by 188 individuals from a potential pool of employable interviewers. Preferences for interviewing targets and locations, prior experience, and perceived dangerousness of the mentally ill were measured. The mentally ill are among the least preferred targets. Locations implying higher levels of control and cooperation were desired. Using a path analysis, preference for interviewing the mentally ill was most affected by diversity of prior contact and the perception of dangerousness
Law, Liberty and the Rule of Law (in a Constitutional Democracy)
In the hunt for a better--and more substantial--awareness of the ālaw,ā The author intends to analyze the different notions related to the ārule of lawā and to criticize the conceptions that equate it either to the sum of ālawā and āruleā or to the formal assertion that ālaw rules,ā regardless of its relationship to certain principles, including both ānegativeā and āpositiveā liberties. Instead, he pretends to scrutinize the principles of the ārule of law,ā in general, and in a āconstitutional democracy,ā in particular, to conclude that the tendency to reduce the ādemocratic principleā to the āmajority ruleā (or āmajority principleā), i.e. to whatever pleases the majority, as part of the āpositive liberty,ā is contrary both to the ānegative libertyā and to the ārule of lawā itself
DinamiÄko-kinetiÄka MRI kraljeÅ”nice pri uspravnom položaju i uz optereÄenje: pMRI/kMRI
The purpose of the study was to demonstrate the general utility of the first dedicated magnetic resonance imaging (MRI) unit enabling upright, weight-bearing positional evaluation of the spinal column (pMRI) during various dynamic-kinetic maneuvers (kMRI) in patients with degenerative conditions of the spine. This study consisted of a prospective analysis of cervical or lumbar imaging examinations. All studies were performed on a recently introduced whole body MRI system (IndomitableTM, Fonar Corp, Melville, NY). The system operates at 0.6T using an electromagnet with a horizontal field, transverse to the longitudinal axis of the patient\u27s body. Depending upon spinal level, all examinations were acquired with either a cervical or lumbar solenoidal radiofrequency receiver coil. This unit is configured with a top-open design, incorporating a patient-scanning table with tilt, translation and elevation functions. The unique motorized patient handling system developed for the scanner allows for vertical (upright, weight bearing) and horizontal (recumbent) positioning of all patients. The top-open construction also allows for dynamic-kinetic flexion and extension maneuvers of the spine. Patterns of bony and soft tissue change occurring among recumbent (rMRI) and upright neutral positions (pMRI), and dynamic-kinetic acquisitions (kMRI) were sought.
Depending on the specific underlying pathologic degenerative condition, significant alterations observed on pMRI and kMRI that were either more or less pronounced than on rMRI included: fluctuating anterior and posterior disc herniations, hypermobile spinal instability, central spinal canal and spinal neural foramen stenosis and general sagittal spinal contour changes. No patient suffered from the feelings of claustrophobia requiring termination of the examination.
To conclude, the potential relative beneficial aspects of upright, weight-bearing (pMRI), dynamic-kinetic (kMRI) spinal imaging on this system over that of recumbent MRI (rMRI) include: the revelation of occult disease dependent on true axial loading, the unmasking of kinetic-dependent disease, and the ability to scan the patient in the position of clinically relevant signs and symptoms. This imaging unit also demonstrated low claustrophobic potential and yielded relatively high-resolution images with little motion/chemical artifact.Cilj ispitivanja bio je pokazati opÄu korisnost prvoga ureÄaja za prikazivanje magnetskom rezonancijom (MRI) koji omoguÄuje pozicijsku procjenu kraljeÅ”nice u uspravnom položaju i pri optereÄenju (pMRI) za vrijeme razliÄitih dinamiÄko-kinetiÄkih zahvata (kMRI) u bolesnika s degenerativnim promjenama kraljeÅ”nice. Istraživanje je obuhvatilo prospektivnu analizu oslikavanja cervikalnog i lumbalnog podruÄja. Sva su istraživanja izvedena na nedavno uvedenom MRI ureÄaju za cijelo tijelo (Indomitablea, Fonar Corp, Melville, NY). Sustav radi pri 0,6 T, uporabom elektromagneta s horizontalnim poljem, popreÄnim na uzdužnu os bolesnikova tijela. Ovisno o spinalnoj razini, svi su pregledi obavljeni s cervikalnom ili lumbalnom prijemnom solenoidnom zavojnicom radiofrekvencije. UreÄaj je na vrhu otvoren, a sastoji se od stola za skeniranje koji se može naginjati, pomicati i podizati. Jedinstveni motorom pokretani sustav za namjeÅ”tanje bolesnika, konstruiran za potrebe skenera, omoguÄuje okomit (uspravan, uz optereÄenje) i vodoravan (ležeÄi) položaj svih bolesnika. Izvedba s otvorom na gornjem dijelu omoguÄuje dinamiÄko-kinetiÄke fleksijske i ekstenzijske zahvate na kraljeÅ”nici. Traženi su uzorci promjena koÅ”tanog i mekog tkiva u ležeÄem položaju (rMRI) i uspravnoj neutralnoj poziciji (pMRI), te dinamiÄko-kinetiÄkim akvizicijama (kMRI).
Ovisno o specifiÄnom patoloÅ”kom degenerativnom stanju, na pMRI i kMRI su uoÄene znaÄajne promjene koje su bile viÅ”e ili manje izražene u odnosu na rMRI, obuhvaÄale su fluktuirajuÄe prednje ili stražnje hernijacije diska, hipermobilnu spinalnu nestabilnost, stenozu centralnog spinalnog kanala i spinalnog neuralnog foramena te opÄe promjene sagitalne spinalne konture. Nijedan bolesnik nije imao osjeÄaj klaustrofobije zbog koje bi se pretraga morala prekinuti. Potencijalni relativni aspekti korisnosti MRI kraljeÅ”nice u uspravnom položaju i uz optereÄenje (pMRI) te dinamiÄko-kinetiÄkog (kMRI) prikazivanja na ovom sustavu u odnosu na MRI u ležeÄem položaju (rMRI) obuhvaÄaju: otkrivanje prikrivenih bolesti ovisno o stvarno maksijalnom optereÄenju, razjaÅ”njenje bolesti ovisnih o kinetici, te moguÄnost skeniranja bolesnika u položaju pri kojemu su uoÄljivi kliniÄki važni znakovi i simptomi. Opisani ureÄaj ima mali klaustrofobiÄni potencijal te daje slike relativno visoke rezolucije, s malo artefakata vezanih uz pokrete i kemikalije
More Bang For Your Buck: Quorum-Sensing Capabilities Improve the Efficacy of Suicidal Altruism
Within the context of evolution, an altruistic act that benefits the
receiving individual at the expense of the acting individual is a puzzling
phenomenon. An extreme form of altruism can be found in colicinogenic E. coli.
These suicidal altruists explode, releasing colicins that kill unrelated
individuals, which are not colicin resistant. By committing suicide, the
altruist makes it more likely that its kin will have less competition. The
benefits of this strategy rely on the number of competitors and kin nearby. If
the organism explodes at an inopportune time, the suicidal act may not harm any
competitors. Communication could enable organisms to act altruistically when
environmental conditions suggest that that strategy would be most beneficial.
Quorum sensing is a form of communication in which bacteria produce a protein
and gauge the amount of that protein around them. Quorum sensing is one means
by which bacteria sense the biotic factors around them and determine when to
produce products, such as antibiotics, that influence competition. Suicidal
altruists could use quorum sensing to determine when exploding is most
beneficial, but it is challenging to study the selective forces at work in
microbes. To address these challenges, we use digital evolution (a form of
experimental evolution that uses self-replicating computer programs as
organisms) to investigate the effects of enabling altruistic organisms to
communicate via quorum sensing. We found that quorum-sensing altruists killed a
greater number of competitors per explosion, winning competitions against
non-communicative altruists. These findings indicate that quorum sensing could
increase the beneficial effect of altruism and the suite of conditions under
which it will evolve.Comment: 8 pages, 8 figures, ALIFE '14 conferenc
Amino Acids from Icy Amines: A Radiation-Chemical Approach to Extraterrestrial Synthesis
Detections of amino acids in meteorites go back several decades, with at least 100 such compounds being reported for the Murchison meteorite alone. The presence of these extraterrestrial molecules raises questions as to their formation, abundance, thermal stability, racemization, and possible subsequent reactions. Although all of these topics have been studied in laboratories, such work often involves many variables and unknowns. This has led us to seek out model systems with which to uncover reaction products, test chemical predictions, and sited light on underlying reaction mechanisms. This presentation will describe one such study, focusing on amino-acid formation in ices
The Escherichia coli phage-shock-protein (psp) operon
The phage-shock-protein (psp) operon helps to ensure survival of Escherichia coli in tate stationary phase at alkaline pH, and protects the cell against dissipation of its proton-motive force against challenge. It is strongly induced by filamentous phage pIV and its bacterial homologues, and by mutant porins that don't localize properly, as well as by a number of other stresses. Transcription of the operon is dependent on sigma(54) and a constitutively active, autogenously controlled activator. psp-operon expression is controlled by one negatively and several positively acting regulators, none of which is a DNA-binding protein. The major product of the operon, PspA, may also serve as a negative regulator of an unusual porin, OmpG
The PspA protein of Escherichia coli is a negative regulator of sigma(54)-dependent transcription
In Eubacteria, expression of genes transcribed by an RNA polymerase holoenzyme containing the alternate sigma factor sigma(54) is positively regulated by proteins belonging to the family of enhancer-binding proteins (EBPs), These proteins bind to upstream activation sequences and are required for the initiation of transcription at the sigma(54)-dependent promoters. They are typically inactive until modified in their N-terminal regulatory domain either by specific phosphorylation or by the binding of a small effector molecule. EBPs lacking this domain, such as the PspF activator of the sigma(54)-dependent pspA promoter, are constitutively active. We describe here the in vivo and in vitro properties of the PspA protein of Escherichia coli, which negatively regulates expression of the pspA promoter without binding DNA directly
Analysis of Volatile Organic Compounds in the Apollo Next Generation Sample Analysis (ANGSA) 73002 Core Sample
Understanding the organic content of lunar regolith was an early priority upon the return of Apollo samples, with amino acids being of special interest because of their importance to life on Earth and their astrobiological relevance. Many initial studies focused on the detection of amino acids in these samples and attempts to determine the origin of those compounds. Although no consensus on the origin of the amino acids was reached in those early studies, more recent work determined that the detected amino acids originated from both terrestrial contamination and meteoritic or cometary in fall to the lunar surface. A majority of the amino acids in the Apollo samples studied originated from precursor molecules, either indigenous to the lunar samples or contaminants, that reacted during the water extraction and acid hydrolysis process for analysis in the laboratory, but the identities of the amino acid precursors still remain poorly understood. Such precursors could include hydrogen cyanide (HCN) and other volatile organic compounds such as amines, carboxylic acids, or aldehydes and ketones. The identities of these compounds, as well as the effects of years of curation on their abundances in lunar regolith samples stored at ambient temperature under nitrogen gas purge, are not clear. The specially curated samples available through the Apollo Next Generation Sample Analysis (ANGSA) program provide a unique opportunity to use state-of- the-art analytical techniques to examine previously unstudied lunar materials. The ANGSA samples include three types of samples: 1) samples stored frozen since <1 month after Earth arrival; 2) samples stored under helium; and 3) a double drive tube collected by Apollo 17 astronauts, with the bottom portion of the drive tube sealed under vacuum on the Moon and never opened. In contrast to the typically curated Apollo samples that have been kept for decades at room temperature under flowing nitrogen purge that may have significantly reduced the abundance of volatiles, the vacuum-sealed and frozen samples may have enhanced preservation of these volatiles. Our initial investigation examines amino acids and their potential volatile precursors, including hydrogen cyanide (HCN), aldehydes, ketones, amines, and mono-carboxylic acids, in a sample from the top portion of the Apollo 17 double drive tube. These results will aid in understanding the lunar abundances of these molecules and will also be compared to future analyses of other drive tube and frozen ANGSA samples
Liberal equality: political not erinaceous
Ronald Dworkinās Justice for Hedgehogs defends liberal political morality on the basis of a rich account of dignity as constitutive of living well. This article raises the Rawlsian concern that making political morality dependent on ethics threatens citizensā political autonomy. Thereafter, it addresses whether the abandonment of (erinaceous) ethical foundations signals the demise of Dworkinās liberalism and explores the possibility of laundering his conception so as to facilitate a marriage between the political philosophies of Rawls and Dworkin. The article finishes by rebutting some objections Dworkin raises against Rawlsās account of public reason
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