2,523 research outputs found
Think Different: Applying the Old Macintosh Mantra to the Computability of the SUSY Auxiliary Field Problem
Starting with valise supermultiplets obtained from 0-branes plus field
redefinitions, valise adinkra networks, and the "Garden Algebra," we discuss an
architecture for algorithms that (starting from on-shell theories and, through
a well-defined computation procedure), search for off-shell completions. We
show in one dimension how to directly attack the notorious "off-shell auxiliary
field" problem of supersymmetry with algorithms in the adinkra network-world
formulation.Comment: 28 pages, 1 figur
Contemporary and Future Approaches to Precision Medicine in Inherited Cardiomyopathies: JACC Focus Seminar 3/5
Inherited cardiomyopathies are commonly occurring myocardial disorders that are associated with substantial morbidity and mortality. Clinical management strategies have focused on treatment of heart failure and arrhythmic complications in symptomatic patients according to standardized guidelines. Clinicians are now being urged to implement precision medicine, but what does this involve? Advances in understanding of the genetic underpinnings of inherited cardiomyopathies have brought new possibilities for interventions that are tailored to genes, specific variants, or downstream mechanisms. However, the phenotypic variability that can occur with any given pathogenic variant suggests that factors other than single driver gene mutations are often involved. This is propelling a new imperative to elucidate the nuanced ways in which individual combinations of genetic variation, comorbidities, and lifestyle may influence cardiomyopathy phenotypes. Here, Part 3 of a 5-part precision medicine Focus Seminar series reviews the current status and future opportunities for precision medicine in the inherited cardiomyopathies
Brimonidine prevents axonal and somatic degeneration of retinal ganglion cell neurons
<p>Abstract</p> <p>Background</p> <p>Brimonidine is a common drug for lowering ocular pressure and may directly protect retinal ganglion cells in glaucoma. The disease involves early loss of retinal ganglion cell transport to brain targets followed by axonal and somatic degeneration. We examined whether brimonidine preserves ganglion cell axonal transport and abates degeneration in rats with elevated ocular pressure induced by laser cauterization of the episcleral veins.</p> <p>Results</p> <p>Ocular pressure was elevated unilaterally by 90% for a period of 8 weeks post- cauterization. During this time, brimonidine (1mg/kg/day) or vehicle (phosphate-buffered saline) was delivered systemically and continuously via subcutaneous pump. Animals received bilateral intravitreal injections of fluorescent cholera toxin subunit β (CTB) two days before sacrifice to assess anterograde transport. In retinas from the vehicle group, elevated pressure induced a 44% decrease in the fraction of ganglion cells with intact uptake of CTB and a 14-42% reduction in the number of immuno-labelled ganglion cell bodies, with the worst loss occurring nasally. Elevated pressure also caused a 33% loss of ganglion cell axons in vehicle optic nerves and a 70% decrease in CTB transport to the superior colliculus. Each of these components of ganglion cell degeneration was either prevented or significantly reduced in the brimonidine treatment group.</p> <p>Conclusions</p> <p>Continuous and systemic treatment with brimonidine by subcutaneous injection significantly improved retinal ganglion cell survival with exposure to elevated ocular pressure. This effect was most striking in the nasal region of the retina. Brimonidine treatment also preserved ganglion cell axon morphology, sampling density and total number in the optic nerve with elevated pressure. Consistent with improved outcome in the optic projection, brimonidine also significantly reduced the deficits in axonal transport to the superior colliculus associated with elevated ocular pressure. As transport deficits to and from retinal ganglion cell projection targets in the brain are relevant to the progression of glaucoma, the ability of brimonidine to preserve optic nerve axons and active transport suggests its neuroprotective effects are relevant not only at the cell body, but throughout the entire optic projection.</p
Temporal Response of Rabbits to β-Adrenergic Agonist Feeding: Tissue Weight, Calpains and Calpastatin Activities, and Nucleic Acid and Protein Concentrations
Forty-eight crossbred rabbits were used in three replications of a 2 x 4 factorial arrangement to investigate the short-term responses of tissue accretion, calpains and calpastatin activity, and nucleic acid and protein concentrations to β- adrenergic agonist (BAA) feeding. Rabbits were fed a 17% CP diet with or without 7 ppm of L644,969 and slaughtered after 1, 4, 8, or 16 d of treatment. Empty body dressing percentage and biceps femoris weight (as a percentage of empty body weight [EBWI) were significantly higher in the treated rabbits than in the controls after 16 d of treatment. Heart and liver weights (as a percentage of EBW) were higher ( P \u3c .05) after 1 d and liver weight (as a percentage of EBW) was lower (P \u3c .05) after 16 d in treated vs controls. Except for an elevation of skeletal muscle m-calpain after 16 d, BAA-supplementation did not affect the calpain-calpastatin system. Muscle RNA concentrations and RNA:DNA ratios were higher (P \u3c .05) in treated rabbits after 1 d and remained higher thereafter. Protein:RNA ratios were lower ( P \u3c .0 1) in treated than in control rabbits after 4 d and remained lower throughout the trial. Muscle DNA content was lower after 4 d and higher after 16 d; RNA content was higher after 4, 8, and 16 d; and protein content was higher after 16 d in treated vs control rabbits. Liver nucleic acid and protein concentrations were not affected by BAA treatment. Heart RNA:DNA ratios were higher ( P \u3c .0 1) after 1 d and protein:RNA ratios were lower (P \u3c .05) after 4 d in the treated rabbits than in the controls. Collectively, these data imply that BAA-induced muscle growth in rabbits occurs through hyperplasia and seems to be related to elevated protein synthetic capacity
Parenting and toddler self‐regulation in low‐income families: What does sleep have to do with it?
Toddlerhood is a sensitive period in the development of self‐regulation, a set of adaptive skills that are fundamental to mental health and partly shaped by parenting. Healthy sleep is known to be critical for self‐regulation; yet, the degree to which child sleep alters interactive child–parent processes remains understudied. This study examines associations between observed parenting and toddler self‐regulation, with toddler sleep as a moderator of this association. Toddlers in low‐income families (N = 171) and their mothers were videotaped during free play and a self‐regulation challenge task; videos were coded for mothers’ behavior and affect (free play) and toddlers’ self‐regulation (challenge task). Mothers reported their child’s nighttime sleep duration via questionnaire. Results revealed significant Sleep × Maternal Negative Affect and Sleep × Maternal Negative Control interactions. Children who did not experience negative parenting had good self‐regulation regardless of their nighttime sleep duration. For children who did experience negative parenting, self‐regulation was intact among those who obtained more nighttime sleep, but significantly poorer among children who were getting less nighttime sleep. Thus, among children who were reported to obtain less nighttime sleep, there were more robust associations between negative parenting and poorer self‐regulation than among toddlers who were reported to obtain more sleep.RESUMENLos primeros años de la niñez son un período sensible en el desarrollo de la auto‐regulación, un grupo de habilidades adaptables que son fundamentales para la salud mental y a las que en parte les da forma la crianza. Es sabido que el dormir bien es esencial para la auto‐regulación y, aun así, el nivel al que el sueño del niño altera los procesos interactivos entre progenitor y niño permanece poco estudiado. Este estudio examina las asociaciones entre la crianza observada y la auto‐regulación del niño pequeño, tomando como moderador de tal asociación el proceso de dormir del niño pequeño. Se grabó en video a niños pequeños de familias de bajos ingresos (N=171) y sus madres durante una sesión de juego libre y una tarea de auto‐regulación que suponía un reto; los videos fueron codificados en cuanto al comportamiento y afecto de las madres (juego libre) y la auto‐regulación de los niños pequeños (tarea que suponía reto). Las madres reportaron acerca del sueño nocturno de sus niños por medio de un cuestionario. Los resultados revelaron interacciones significativas en cuanto al dormir y el negativo afecto materno, así como el dormir y el negativo control materno. Los niños que no experimentaron una crianza negativa tenían una buena auto‐regulación independientemente de la duración de su sueño nocturno. En el caso de los niños que experimentaron una crianza negativa, la auto‐regulación quedó intacta en aquellos que lograban más tiempo nocturno de dormir, pero fue significativamente más pobre en los niños que tenían menos tiempo de sueño nocturno. Por tanto, en el caso de los niños indicados en el reporte con menos tiempo de dormir nocturno, se dieron asociaciones más robustas entre la crianza negativa y una más pobre auto‐regulación que entre los niños pequeños indicados en el reporte con más tiempo de dormir.RÉSUMÉLa petite enfance est une période sensible dans le développement de l’auto‐régulation, un ensemble de compétences qui sont fondamentales pour la santé mentale et en partie formées par le parentage. L’on sait qu’un sommeil sain est critique pour l’auto‐régulation et pourtant la mesure dans laquelle le sommeil de l’enfant altère les processus interactifs enfant‐parent demeure peu étudiée. Cette étude examine les liens entre le parentage observé et l’auto‐régulation du petit enfant, le sommeil de l’enfant ayant un effet modérateur dans ce lien. Des jeunes enfants de familles issues de milieux défavorisés (N=171) et leurs mères ont été filmés durant un jeu libre et un exercice de défi d’auto‐régulation. Les vidéos ont été codées pour le comportement des mères et l’affect (jeu libre) et l’auto‐régulation des jeunes enfants (exercice de défi). Les mères ont fait état de la durée de sommeil nocturne de leur enfant au moyen d’un questionnaire. Les résultats ont révélé que : sommeil significatif x l’affect négatif maternel et le sommeil x négatif maternel contrôle les interactions. Les enfants qui n’avaient pas fait l’expérience d’un parentage négatif avaient une bonne auto‐régulation quelle qu’ait été la durée du sommeil nocturne. Pour les enfants ayant fait l’expérience d’une parentage négatif, l’auto‐régulation était intacte chez ceux ayant plus dormi, mais bien moindre chez les enfants qui avaient moins dormi. Donc, chez les enfants ayant moins de sommeil nocturne les liens bien plus robustes ont été découverts entre le parentage négatif et une moindre auto‐régulation que chez les petits enfants dormant plus durant la nuit.ZUSAMMENFASSUNGDas Kleinkindalter ist ein sensibler Zeitraum für die Entwicklung der Selbstregulation – einer Reihe von Anpassungsfähigkeiten, die für die psychische Gesundheit grundlegend sind und teilweise durch Erziehung geprägt werden. Gesunder Schlaf ist bekanntlich entscheidend für die Selbstregulation, aber das Ausmaß, in dem der Kinderschlaf interaktive Prozesse zwischen Kind und Eltern verändert, ist bisher nur unzureichend erforscht wurden. Diese Studie untersucht Zusammenhänge zwischen beobachtetem Erziehungsverhalten und der Selbstregulation von Kleinkindern, wobei der Schlaf der Kleinkinder als Moderator dieser Assoziation fungiert. Kleinkinder aus einkommensschwachen Familien (N=171) und ihre Mütter wurden während des freien Spiels und einer herausfordernden Aufgabe zur Selbstregulation gefilmt; die Videos wurden für das Verhalten und die Affekte der Mütter (freies Spiel) und die Selbstregulation der Kleinkinder (herausfordernde Aufgabe) kodiert. Die Mütter berichteten per Fragebogen über die nächtliche Schlafdauer ihres Kindes. Die Ergebnisse zeigten signifikante Interaktionen für Schlaf und mütterlichen negativen Affekt sowie für Schlaf und mütterliche negative Kontrollinteraktionen. Kinder, die keine negative Erziehung erlebten, hatten eine gute Selbstregulation, unabhängig von ihrer nächtlichen Schlafdauer. Bei Kindern, die eine negative Erziehung erfuhren, war die Selbstregulation bei denen, die mehr Nachtschlaf erhielten, intakt und bei Kindern, die weniger Nachtschlaf erhielten, jedoch deutlich schlechter. So gab es bei Kindern, von denen berichtet wurde, dass sie weniger Nachtschlaf erhielten, robustere Assoziationen zwischen negativer Erziehung und schlechterer Selbstregulation als bei Kleinkindern, von denen berichtet wurde, dass sie mehr Schlaf erhielten.抄録低収入家庭における子育てと幼児の自己調整力:睡眠が関与するものとは何か?幼児期は、自己調整力、つまりメンタルヘルスの基礎であり、ある程度までは子育てによって形成される、一連の適応スキルの発達が影響を受けやすい時期である。健康的な睡眠は自己調整力には不可欠のものとして知られているが、子どもの睡眠が子どもと親の相互作用の過程をどの程度まで改めるかについては、いまもなお研究課題のままである。本研究は、観察によって得られた子育てと幼児の自己調整力の関連性について幼児の睡眠を仲介として検討することである。低所得家庭 (N=171) で生活している幼児と母親が自由遊びと自己調整のチャレンジタスクに取り組む間中ビデオ録画した。ビデオデータは母親の行動と感情(自由遊び)と幼児の自己調整力(チャレンジタスク)としてコード化された。子どもの夜間の睡眠時間は母親からの質問紙を通して報告された。その結果、睡眠と母親の否定的感情の間、そして睡眠と母親の否定的コントロールの間には著しい相互関連性が認められた。否定的育児を経験していない子どもは、夜間の睡眠時間に関わらず、よい自己調整力を持っていた。否定的育児を経験した子どもでは、自己調整力はより長い夜間睡眠をとっている子どもにおいては保たれていたが、より短い睡眠時間しかとっていない子どもにおいては著しく低かった。このようにより短い睡眠時間しかとっていないと報告された子どもにおいては、より長い睡眠をとっている幼児より、否定的育児とより低い自己調整力の間により確かな関連性が示された。摘要低收入家庭的育兒和幼兒自我調節:與睡眠有什麼關係?幼兒期是自我調節發展的一個敏感時期, 這是一套適應性技能, 是心理健康的基礎, 部分由養育方式塑造。眾所周知, 健康睡眠對於自我調節至關重要, 然而, 兒童睡眠如何改變兒童 ‐ 父母互動仍未得到充分研究。本研究探討觀察到的養育方式與幼兒自我調節的關聯, 及幼兒睡眠作為這種關聯的調節變數。低收入家庭的幼兒 (N = 171) 和母親在自由遊戲和自我調節挑戰任務中被錄像; 視頻被編碼為母親的行為和情感 (自由遊戲) 和幼兒的自我調節 (挑戰任務)。母親通過問卷報告孩子的夜間睡眠時間。結果顯示顯著的睡眠x母體負面情感和睡眠 x 母體負面控制相互作用。沒有經歷負面養育的孩子, 無論夜間睡眠時間長短, 都有良好的自我調節能力。對於那些經歷過負面養育的孩子, 在夜間睡眠較多的人中, 自我調節是完整的, 但在夜間睡眠較少的孩子中, 自我調節顯著較差。因此, 在夜間睡眠較少的兒童中, 負面育兒和較差的自我調節的關聯性強於較多睡眠的幼兒。ملخصالرعاية الوالدية والتنظيم الذاتي للطفل في الأسر ذات الدخل المنخفض: ما علاقة النوم بذلك ؟الطفولة هي فتره حساسة في تطوير التنظيم الذاتي ، والذي يمثل مجموعه من المهارات التكيفيه التي هي أساسيه للصحة النفسية وتتشكل جزئيا عن طريق الأبوه والأمومه. ومن المعروف ان النوم الصحي أمر بالغ الاهميه للتنظيم الذاتي ، ومع ذلك ، فان الدرجة التي يغير بها نوم الطفل في العمليات التفاعلية التي يقوم بها الطفل مع الوالدين لا تزال غير خاضعة للدراسة الكافية. تتناول هذه الدراسة العلاقات بين الرعاية الوالدية الملحوظة والتنظيم الذاتي للطفل الصغير ، حيث نوم الطفل يمثل المتغير الوسيط في هذه العلاقة. اشترك في الدراسة مجموعة من الأطفال الصغار في الأسر ذات الدخل المنخفض (العدد = 171) وأمهاتهم وتم تصويرهم بالفيديو اثناء اللعب الحر مع تكليفهم بمهمة تحدي التنظيم الذاتي ؛ تم ترميز تسجيلات الفيديو لسلوك الأمهات وعاطفتهم في (اللعب الحر) والتنظيم الذاتي للأطفال الصغار في (مهمة التحدي). وأبلغت الأمهات عن مده النوم الليلي لأطفالهن عن طريق الاستبيان. أظهرت النتائج تفاعلات ذات دلالة إحصائية بين النوم والعاطفة السلبية عند الأمهات وبين النوم والسيطرة السلبية للأمهات . الأطفال الذين لا يعانون من الابوه والامومه السلبية كان لديهم قدرات جيدة على التنظيم الذاتي بغض النظر عن مده النوم ليلا. بالنسبة للأطفال الذين يعانون من الابوه والامومه السلبية ، كان التنظيم الذاتي سليما بين أولئك الذين حصلوا علي المزيد من النوم ليلا ، ولكن أضعف بكثير بين الأطفال الذين كانوا يحصلون علي اقل النوم ليلا. وبالتالي ، فانه من بين الأطفال الذين ابلغ عن حصولهم علي قسط اقل من النوم الليلي ، كانت هناك رابطات اقوي بين الرعاية الوالدية السلبية والتنظيم الذاتي الأقل منها بين الصغار الذين أفيد بأنهم يحصلون علي المزيد من النوم.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/150525/1/imhj21783.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/150525/2/imhj21783_am.pd
Two 'b's in the Beehive: The Discovery of the First Hot Jupiters in an Open Cluster
We present the discovery of two giant planets orbiting stars in Praesepe
(also known as the Beehive Cluster). These are the first known hot Jupiters in
an open cluster and the only planets known to orbit Sun-like, main-sequence
stars in a cluster. The planets are detected from Doppler shifted radial
velocities; line bisector spans and activity indices show no correlation with
orbital phase, confirming the variations are caused by planetary companions.
Pr0201b orbits a V=10.52 late F dwarf with a period of 4.4264 +/- 0.0070 days
and has a minimum mass of 0.540 +/- 0.039 Mjup, and Pr0211b orbits a V=12.06
late G dwarf with a period of 2.1451 +/- 0.0012 days and has a minimum mass of
1.844 +/- 0.064 Mjup. The detection of 2 planets among 53 single members
surveyed establishes a lower limit on the hot Jupiter frequency of 3.8
(+5.0)(-2.4) % in this metal-rich open cluster. Given the precisely known age
of the cluster, this discovery also demonstrates that, in at least 2 cases,
giant planet migration occurred within 600 Myr after formation. As we endeavor
to learn more about the frequency and formation history of planets,
environments with well-determined properties -- such as open clusters like
Praesepe -- may provide essential clues to this end.Comment: 5 pages, 3 tables, 2 figures. Published in ApJ Letter
Spectroscopic Discovery of the Supernova 2003dh Associated with GRB 030329
We present early observations of the afterglow of the Gamma-Ray Burst (GRB)
030329 and the spectroscopic discovery of its associated supernova SN 2003dh.
We obtained spectra of the afterglow of GRB 030329 each night from March 30.12
(0.6 days after the burst) to April 8.13 (UT) (9.6 days after the burst). The
spectra cover a wavelength range of 350 nm to 850 nm. The early spectra consist
of a power-law continuum (F_nu ~ nu^{-0.9}) with narrow emission lines
originating from HII regions in the host galaxy, indicating a low redshift of
z=0.1687. However, our spectra taken after 2003 Apr. 5 show broad peaks in flux
characteristic of a supernova. Correcting for the afterglow emission, we find
the spectrum of the supernova is remarkably similar to the type Ic `hypernova'
SN 1998bw. While the presence of supernovae have been inferred from the light
curves and colors of GRB afterglows in the past, this is the first direct,
spectroscopic confirmation that a subset of classical gamma-ray bursts
originate from supernovae.Comment: published by ApJ Letters; additional material avilable at
http://cfa-www.harvard.edu/cfa/oir/Research/GRB
Deep Photometry of GRB 041006 Afterglow: Hypernova Bump at Redshift z=0.716
We present deep optical photometry of the afterglow of gamma-ray burst (GRB)
041006 and its associated hypernova obtained over 65 days after detection (55
R-band epochs on 10 different nights). Our early data (t<4 days) joined with
published GCN data indicates a steepening decay, approaching F_nu ~t^{-0.6} at
early times (<<1 day) and F_nu ~t^{-1.3} at late times. The break at
t_b=0.16+-0.04 days is the earliest reported jet break among all GRB
afterglows. During our first night, we obtained 39 exposures spanning 2.15
hours from 0.62 to 0.71 days after the burst that reveal a smooth afterglow,
with an rms deviation of 0.024 mag from the local power-law fit, consistent
with photometric errors. After t~4 days, the decay slows considerably, and the
light curve remains approximately flat at R~24 mag for a month before decaying
by another magnitude to reach R~25 mag two months after the burst. This
``bump'' is well-fitted by a k-corrected light curve of SN1998bw, but only if
stretched by a factor of 1.38 in time. In comparison with the other GRB-related
SNe bumps, GRB 041006 stakes out new parameter space for GRB/SNe, with a very
bright and significantly stretched late-time SN light curve. Within a small
sample of fairly well observed GRB/SN bumps, we see a hint of a possible
correlation between their peak luminosity and their ``stretch factor'', broadly
similar to the well-studied Phillips relation for the type Ia supernovae.Comment: ApJ Letters, accepted. Additional material available at
ftp://cfa-ftp.harvard.edu/pub/kstanek/GRB041006
Hat-P-28b and Hat-P-29b: Two Sub-Jupiter Mass Transiting Planets
We present the discovery of two transiting exoplanets. HAT-P-28b orbits a V = 13.03 G3 dwarf star with a period P = 3.2572 days and has a mass of 0.63 ± 0.04 M_J and a radius of 1.21^(+0.11)_(–0.08) R_J yielding a mean density of 0.44 ± 0.09 g cm^(–3). HAT-P-29b orbits a V = 11.90 F8 dwarf star with a period P = 5.7232 days and has a mass of 0.78^(+0.08)_(–0.04) M_J and a radius of 1.11^(+0.14)_(–0.08) R_J yielding a mean density of 0.71 ± 0.18 g cm^(–3). We discuss the properties of these planets in the context of other known transiting planets
Photometry and Spectroscopy of GRB 030329 and Its Associated Supernova 2003dh: The First Two Months
We present extensive optical and infrared photometry of the afterglow of
gamma-ray burst (GRB) 030329 and its associated supernova (SN) 2003dh over the
first two months after detection (2003 March 30-May 29 UT). Optical
spectroscopy from a variety of telescopes is shown and, when combined with the
photometry, allows an unambiguous separation between the afterglow and
supernova contributions. The optical afterglow of the GRB is initially a
power-law continuum but shows significant color variations during the first
week that are unrelated to the presence of a supernova. The early afterglow
light curve also shows deviations from the typical power-law decay. A supernova
spectrum is first detectable ~7 days after the burst and dominates the light
after ~11 days. The spectral evolution and the light curve are shown to closely
resemble those of SN 1998bw, a peculiar Type Ic SN associated with GRB 980425,
and the time of the supernova explosion is close to the observed time of the
GRB. It is now clear that at least some GRBs arise from core-collapse SNe.Comment: 57 pages, 13 figures, accepted by ApJ, revised per referee's
comments, includes full photometry table. Data available at
ftp://cfa-ftp.harvard.edu/pub/kstanek/GRB030329 or through WWW at
http://cfa-www.harvard.edu/cfa/oir/Research/GRB
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