1,690 research outputs found
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The Internal Circadian Clock Increases Hunger and Appetite in the Evening Independent of Food Intake and Other Behaviors
Objective: Despite the extended overnight fast, paradoxically, people are typically not ravenous in the morning and breakfast is typically the smallest meal of the day. Here we assessed whether this paradox could be explained by an endogenous circadian influence on appetite with a morning trough, while controlling for sleep/wake and fasting/feeding effects. Design and Methods We studied 12 healthy non-obese adults (6 male; age, 20–42 year) throughout a 13-day laboratory protocol that balanced all behaviors, including eucaloric meals and sleep periods, evenly across the endogenous circadian cycle. Participants rated their appetite and food preferences by visual analog scales. Results: There was a large endogenous circadian rhythm in hunger, with the trough in the biological morning (8 AM) and peak in the biological evening (8 PM; peak-to-trough amplitude=17%; P=0.004). Similarly phased significant endogenous circadian rhythms were present in appetite for sweets, salty and starchy foods, fruits, meats/poultry, food overall, and for estimates of how much food participants could eat (amplitudes 14–25%; all P < 0.05). Conclusions: In people who sleep at night, the intrinsic circadian evening peak in appetite may promote larger meals before the fasting period necessitated by sleep. Furthermore, the circadian decline in hunger across the night would theoretically counteract the fasting-induced hunger increase that could otherwise disrupt sleep
Simulating galaxies in the reionization era with FIRE-2: morphologies and sizes
We study the morphologies and sizes of galaxies at z>5 using high-resolution
cosmological zoom-in simulations from the Feedback In Realistic Environments
project. The galaxies show a variety of morphologies, from compact to clumpy to
irregular. The simulated galaxies have more extended morphologies and larger
sizes when measured using rest-frame optical B-band light than rest-frame UV
light; sizes measured from stellar mass surface density are even larger. The UV
morphologies are usually dominated by several small, bright young stellar
clumps that are not always associated with significant stellar mass. The B-band
light traces stellar mass better than the UV, but it can also be biased by the
bright clumps. At all redshifts, galaxy size correlates with stellar
mass/luminosity with large scatter. The half-light radii range from 0.01 to 0.2
arcsec (0.05-1 kpc physical) at fixed magnitude. At z>5, the size of galaxies
at fixed stellar mass/luminosity evolves as (1+z)^{-m}, with m~1-2. For
galaxies less massive than M_star~10^8 M_sun, the ratio of the half-mass radius
to the halo virial radius is ~10% and does not evolve significantly at z=5-10;
this ratio is typically 1-5% for more massive galaxies. A galaxy's "observed"
size decreases dramatically at shallower surface brightness limits. This effect
may account for the extremely small sizes of z>5 galaxies measured in the
Hubble Frontier Fields. We provide predictions for the cumulative light
distribution as a function of surface brightness for typical galaxies at z=6.Comment: 11 pages, 11 figures, resubmitted to MNRAS after revision for
referee's comment
Formation of Globular Cluster Candidates in Merging Proto-galaxies at High Redshift: A View from the FIRE Cosmological Simulations
Using a state-of-the-art cosmological simulation of merging proto-galaxies at
high redshift from the FIRE project, with explicit treatments of star formation
and stellar feedback in the interstellar medium, we investigate the formation
of star clusters and examine one of the formation hypothesis of present-day
metal-poor globular clusters. We find that frequent mergers in high-redshift
proto-galaxies could provide a fertile environment to produce long-lasting
bound star clusters. The violent merger event disturbs the gravitational
potential and pushes a large gas mass of ~> 1e5-6 Msun collectively to high
density, at which point it rapidly turns into stars before stellar feedback can
stop star formation. The high dynamic range of the reported simulation is
critical in realizing such dense star-forming clouds with a small dynamical
timescale, t_ff <~ 3 Myr, shorter than most stellar feedback timescales. Our
simulation then allows us to trace how clusters could become virialized and
tightly-bound to survive for up to ~420 Myr till the end of the simulation.
Because the cluster's tightly-bound core was formed in one short burst, and the
nearby older stars originally grouped with the cluster tend to be
preferentially removed, at the end of the simulation the cluster has a small
age spread.Comment: 14 pages, 14 figures, Accepted for publication in the Monthly Notices
of the Royal Astronomical Society, High-resolution version of this article
also available at http://www.jihoonkim.org/index/research.html#g
Peran Lsm dalam Program Pendampingan Anak Jalanan Menuju Ketahanan Sosial Keluarga (Study Kasus Lsm Ppap Seroja di Kota Surakarta)
Bachtiar Rofi\u27i. “PERAN LSM DALAM PROGRAM PENDAMPINGAN ANAK JALANAN MENUJU KETAHANAN KELUARGA (Study Kasus LSM PPAP Seroja Di Kota Surakarta)”.Skripsi. Surakarta: Fakultas Keguruan dan Ilmu Pendidikan. Universitas Sebelas Maret 2017. Siti Rochani dan Siany Indria Liestyasari. Penelitian betujuan untuk mengetahui: (1) untuk mengidentifikasi bentuk pendampingan LSM yang mengarah pada ketahanan sosial keluarga anak jalanan; (2) untuk mengetahui kendala LSM dalam penerapan pendampingan orangtua dan anak jalanan di Kota Surakarta; (3) Untuk mengetahui dampak dari pola pendampingan LSM terhadap orangtua dan anak jalanan di Kota Surakarta.Penelitian ini termasuk dalam jenis penelitian kualitatif dengan pendekatan study kasus.Pengumpulan data berasal dari wawancara, observasi, serta dokumentasi. Wawancara dilakukan dengan enam informan, yang terdiri dari dua pengurus LSM, dua orangtua anak jalanan, dua anak dampingan LSM diantaranya ada yang masih berprofesi sebagai anak jalanan, dan mantan anak jalanan. Penelitian ini mengunakan tekhnik pengambilan informan dengan cara purposive sampling. Dalam melakukan uji validitas data, yang dilakukan yaitu dengan trianggulasi sumber dan trianggulasi metode.Tekhnik analisis data menggunakan analisis interaktif yang terdiri dari pengumpulan data, reduksi data, penyajian data, dan penarikan data (verivikasi data).Hasil penelitian menunjukan: (1) Pendampingan LSM yang mengarah pada ketahanan sosial keluarga anak jalanan adalah (a) aspek pendidikan, (b) aspek ekonomi, (c) aspek kesehatan, (d) aspek agama, (e) aspek komunikasi, (f) aspek hukum; (2) Kendala LSM dalam penerapan pendampingan orangtua dan anak jalanan di Kota Surakarta adalah (a) kendala internal, (b) kendala eksternal (3) Dampak dari pola pendampingan LSM terhadap orangtua dan anak jalanan di Kota Surakarta mencangkup (a) aspek pendidikan, (b) aspek ekonomi, (c) aspek kesehatan, (d) aspek agama, (e) aspek komunikasi, (f) aspek hukum.Kesimpulan penelitian ini adalah bahwa meningkatkan ketahanan sosial keluarga anak jalanan dianggap solusi yang tepat untuk megurangi angka anak jalanan yang ada di Kota Suarakarta. Kata Kunci : Anak Jalanan, Ketahanan Sosial Keluarg
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Implementing the 2009 Institute of Medicine recommendations on resident physician work hours, supervision, and safety
Long working hours and sleep deprivation have been a facet of physician training in the US since the advent of the modern residency system. However, the scientific evidence linking fatigue with deficits in human performance, accidents and errors in industries from aeronautics to medicine, nuclear power, and transportation has mounted over the last 40 years. This evidence has also spawned regulations to help ensure public safety across safety-sensitive industries, with the notable exception of medicine. In late 2007, at the behest of the US Congress, the Institute of Medicine embarked on a year-long examination of the scientific evidence linking resident physician sleep deprivation with clinical performance deficits and medical errors. The Institute of Medicine’s report, entitled “Resident duty hours: Enhancing sleep, supervision and safety”, published in January 2009, recommended new limits on resident physician work hours and workload, increased supervision, a heightened focus on resident physician safety, training in structured handovers and quality improvement, more rigorous external oversight of work hours and other aspects of residency training, and the identification of expanded funding sources necessary to implement the recommended reforms successfully and protect the public and resident physicians themselves from preventable harm. Given that resident physicians comprise almost a quarter of all physicians who work in hospitals, and that taxpayers, through Medicare and Medicaid, fund graduate medical education, the public has a deep investment in physician training. Patients expect to receive safe, high-quality care in the nation’s teaching hospitals. Because it is their safety that is at issue, their voices should be central in policy decisions affecting patient safety. It is likewise important to integrate the perspectives of resident physicians, policy makers, and other constituencies in designing new policies. However, since its release, discussion of the Institute of Medicine report has been largely confined to the medical education community, led by the Accreditation Council for Graduate Medical Education (ACGME). To begin gathering these perspectives and developing a plan to implement safer work hours for resident physicians, a conference entitled “Enhancing sleep, supervision and safety: What will it take to implement the Institute of Medicine recommendations?” was held at Harvard Medical School on June 17–18, 2010. This White Paper is a product of a diverse group of 26 representative stakeholders bringing relevant new information and innovative practices to bear on a critical patient safety problem. Given that our conference included experts from across disciplines with diverse perspectives and interests, not every recommendation was endorsed by each invited conference participant. However, every recommendation made here was endorsed by the majority of the group, and many were endorsed unanimously. Conference members participated in the process, reviewed the final product, and provided input before publication. Participants provided their individual perspectives, which do not necessarily represent the formal views of any organization. In September 2010 the ACGME issued new rules to go into effect on July 1, 2011. Unfortunately, they stop considerably short of the Institute of Medicine’s recommendations and those endorsed by this conference. In particular, the ACGME only applied the limitation of 16 hours to first-year resident physicans. Thus, it is clear that policymakers, hospital administrators, and residency program directors who wish to implement safer health care systems must go far beyond what the ACGME will require. We hope this White Paper will serve as a guide and provide encouragement for that effort. Resident physician workload and supervision By the end of training, a resident physician should be able to practice independently. Yet much of resident physicians’ time is dominated by tasks with little educational value. The caseload can be so great that inadequate reflective time is left for learning based on clinical experiences. In addition, supervision is often vaguely defined and discontinuous. Medical malpractice data indicate that resident physicians are frequently named in lawsuits, most often for lack of supervision. The recommendations are: The ACGME should adjust resident physicians workload requirements to optimize educational value. Resident physicians as well as faculty should be involved in work redesign that eliminates nonessential and noneducational activity from resident physician dutiesMechanisms should be developed for identifying in real time when a resident physician’s workload is excessive, and processes developed to activate additional providersTeamwork should be actively encouraged in delivery of patient care. Historically, much of medical training has focused on individual knowledge, skills, and responsibility. As health care delivery has become more complex, it will be essential to train resident and attending physicians in effective teamwork that emphasizes collective responsibility for patient care and recognizes the signs, both individual and systemic, of a schedule and working conditions that are too demanding to be safeHospitals should embrace the opportunities that resident physician training redesign offers. Hospitals should recognize and act on the potential benefits of work redesign, eg, increased efficiency, reduced costs, improved quality of care, and resident physician and attending job satisfactionAttending physicians should supervise all hospital admissions. Resident physicians should directly discuss all admissions with attending physicians. Attending physicians should be both cognizant of and have input into the care patients are to receive upon admission to the hospitalInhouse supervision should be required for all critical care services, including emergency rooms, intensive care units, and trauma services. Resident physicians should not be left unsupervised to care for critically ill patients. In settings in which the acuity is high, physicians who have completed residency should provide direct supervision for resident physicians. Supervising physicians should always be physically in the hospital for supervision of resident physicians who care for critically ill patientsThe ACGME should explicitly define “good” supervision by specialty and by year of training. Explicit requirements for intensity and level of training for supervision of specific clinical scenarios should be providedCenters for Medicare and Medicaid Services (CMS) should use graduate medical education funding to provide incentives to programs with proven, effective levels of supervision. Although this action would require federal legislation, reimbursement rules would help to ensure that hospitals pay attention to the importance of good supervision and require it from their training programs Resident physician work hours Although the IOM “Sleep, supervision and safety” report provides a comprehensive review and discussion of all aspects of graduate medical education training, the report’s focal point is its recommendations regarding the hours that resident physicians are currently required to work. A considerable body of scientific evidence, much of it cited by the Institute of Medicine report, describes deteriorating performance in fatigued humans, as well as specific studies on resident physician fatigue and preventable medical errors. The question before this conference was what work redesign and cultural changes are needed to reform work hours as recommended by the Institute of Medicine’s evidence-based report? Extensive scientific data demonstrate that shifts exceeding 12–16 hours without sleep are unsafe. Several principles should be followed in efforts to reduce consecutive hours below this level and achieve safer work schedules. The recommendations are: Limit resident physician work hours to 12–16 hour maximum shiftsA minimum of 10 hours off duty should be scheduled between shiftsResident physician input into work redesign should be actively solicitedSchedules should be designed that adhere to principles of sleep and circadian science; this includes careful consideration of the effects of multiple consecutive night shifts, and provision of adequate time off after night work, as specified in the IOM reportResident physicians should not be scheduled up to the maximum permissible limits; emergencies frequently occur that require resident physicians to stay longer than their scheduled shifts, and this should be anticipated in scheduling resident physicians’ work shiftsHospitals should anticipate the need for iterative improvement as new schedules are initiated; be prepared to learn from the initial phase-in, and change the plan as neededAs resident physician work hours are redesigned, attending physicians should also be considered; a potential consequence of resident physician work hour reduction and increased supervisory requirements may be an increase in work for attending physicians; this should be carefully monitored, and adjustments to attending physician work schedules made as needed to prevent unsafe work hours or working conditions for this group“Home call” should be brought under the overall limits of working hours; work load and hours should be monitored in each residency program to ensure that resident physicians and fellows on home call are getting sufficient sleepMedicare funding for graduate medical education in each hospital should be linked with adherence to the Institute of Medicine limits on resident physician work hours Moonlighting by resident physicians The Institute of Medicine report recommended including external as well as internal moonlighting in working hour limits. The recommendation is: All moonlighting work hours should be included in the ACGME working hour limits and actively monitored. Hospitals should formalize a moonlighting policy and establish systems for actively monitoring resident physician moonlighting Safety of resident physicians The “Sleep, supervision and safety” report also addresses fatigue-related harm done to resident physicians themselves. The report focuses on two main sources of physical injury to resident physicians impaired by fatigue, ie, needle-stick exposure to blood-borne pathogens and motor vehicle crashes. Providing safe transportation home for resident physicians is a logistical and financial challenge for hospitals. Educating physicians at all levels on the dangers of fatigue is clearly required to change driving behavior so that safe hospital-funded transport home is used effectively. Fatigue-related injury prevention (including not driving while drowsy) should be taught in medical school and during residency, and reinforced with attending physicians; hospitals and residency programs must be informed that resident physicians’ ability to judge their own level of impairment is impaired when they are sleep deprived; hence, leaving decisions about the capacity to drive to impaired resident physicians is not recommendedHospitals should provide transportation to all resident physicians who report feeling too tired to drive safely; in addition, although consecutive work should not exceed 16 hours, hospitals should provide transportation for all resident physicians who, because of unforeseen reasons or emergencies, work for longer than consecutive 24 hours; transportation under these circumstances should be automatically provided to house staff, and should not rely on self-identification or request Training in effective handovers and quality improvement Handover practice for resident physicians, attendings, and other health care providers has long been identified as a weak link in patient safety throughout health care settings. Policies to improve handovers of care must be tailored to fit the appropriate clinical scenario, recognizing that information overload can also be a problem. At the heart of improving handovers is the organizational effort to improve quality, an effort in which resident physicians have typically been insufficiently engaged. The recommendations are: Hospitals should train attending and resident physicians in effective handovers of careHospitals should create uniform processes for handovers that are tailored to meet each clinical setting; all handovers should be done verbally and face-to-face, but should also utilize written toolsWhen possible, hospitals should integrate hand-over tools into their electronic medical records (EMR) systems; these systems should be standardized to the extent possible across residency programs in a hospital, but may be tailored to the needs of specific programs and services; federal government should help subsidize adoption of electronic medical records by hospitals to improve signoutWhen feasible, handovers should be a team effort including nurses, patients, and familiesHospitals should include residents in their quality improvement and patient safety efforts; the ACGME should specify in their core competency requirements that resident physicians work on quality improvement projects; likewise, the Joint Commission should require that resident physicians be included in quality improvement and patient safety programs at teaching hospitals; hospital administrators and residency program directors should create opportunities for resident physicians to become involved in ongoing quality improvement projects and root cause analysis teams; feedback on successful quality improvement interventions should be shared with resident physicians and broadly disseminatedQuality improvement/patient safety concepts should be integral to the medical school curriculum; medical school deans should elevate the topics of patient safety, quality improvement, and teamwork; these concepts should be integrated throughout the medical school curriculum and reinforced throughout residency; mastery of these concepts by medical students should be tested on the United States Medical Licensing Examination (USMLE) stepsFederal government should support involvement of resident physicians in quality improvement efforts; initiatives to improve quality by including resident physicians in quality improvement projects should be financially supported by the Department of Health and Human Services Monitoring and oversight of the ACGME While the ACGME is a key stakeholder in residency training, external voices are essential to ensure that public interests are heard in the development and monitoring of standards. Consequently, the Institute of Medicine report recommended external oversight and monitoring through the Joint Commission and Centers for Medicare and Medicaid Services (CMS). The recommendations are: Make comprehensive fatigue management a Joint Commission National Patient Safety Goal; fatigue is a safety concern not only for resident physicians, but also for nurses, attending physicians, and other health care workers; the Joint Commission should seek to ensure that all health care workers, not just resident physicians, are working as safely as possibleFederal government, including the Centers for Medicare and Medicaid Services and the Agency for Healthcare Research and Quality, should encourage development of comprehensive fatigue management programs which all health systems would eventually be required to implementMake ACGME compliance with working hours a “ condition of participation” for reimbursement of direct and indirect graduate medical education costs; financial incentives will greatly increase the adoption of and compliance with ACGME standards Future financial support for implementation The Institute of Medicine’s report estimates that 376 million) will be required just to bring hospitals into compliance with the existing 2003 ACGME rules. Downstream savings to the health care system could potentially result from safer care, but these benefits typically do not accrue to hospitals and residency programs, who have been asked historically to bear the burden of residency reform costs. The recommendations are: The Institute of Medicine should convene a panel of stakeholders, including private and public funders of health care and graduate medical education, to lay down the concrete steps necessary to identify and allocate the resources needed to implement the recommendations contained in the IOM “Resident duty hours: Enhancing sleep, supervision and safety” report. Conference participants suggested several approaches to engage public and private support for this initiativeEfforts to find additional funding to implement the Institute of Medicine recommendations should focus more broadly on patient safety and health care delivery reform; policy efforts focused narrowly upon resident physician work hours are less likely to succeed than broad patient safety initiatives that include residency redesign as a key componentHospitals should view the Institute of Medicine recommendations as an opportunity to begin resident physician work redesign projects as the core of a business model that embraces safety and ultimately saves resourcesBoth the Secretary of Health and Human Services and the Director of the Centers for Medicare and Medicaid Services should take the Institute of Medicine recommendations into consideration when promulgating rules for innovation grantsThe National Health Care Workforce Commission should consider the Institute of Medicine recommendations when analyzing the nation’s physician workforce needs Recommendations for future research Conference participants concurred that convening the stakeholders and agreeing on a research agenda was key. Some observed that some sectors within the medical education community have been reluctant to act on the data. Several logical funders for future research were identified. But above all agencies, Centers for Medicare and Medicaid Services is the only stakeholder that funds graduate medical education upstream and will reap savings downstream if preventable medical errors are reduced as a result of reform of resident physician work hours
Star formation histories of dwarf galaxies in the FIRE simulations: dependence on mass and Local Group environment
We study star formation histories (SFHs) of dwarf galaxies
(stellar mass ) from FIRE-2 cosmological zoom-in
simulations. We compare dwarfs around individual Milky Way (MW)-mass galaxies,
dwarfs in Local Group (LG)-like environments, and true field (i.e. isolated)
dwarf galaxies. We reproduce observed trends wherein higher-mass dwarfs quench
later (if at all), regardless of environment. We also identify differences
between the environments, both in terms of "satellite vs. central" and "LG vs.
individual MWvs. isolated dwarf central." Around the individual MW-mass hosts,
we recover the result expected from environmental quenching: central galaxies
in the "near field" have more extended SFHs than their satellite counterparts,
with the former more closely resemble isolated ("true field") dwarfs (though
near-field centrals are still somewhat earlier forming). However, this
difference is muted in the LG-like environments, where both near-field centrals
and satellites have similar SFHs, which resemble satellites of single MW-mass
hosts. This distinction is strongest for but
exists at other masses. Our results suggest that the paired halo nature of the
LG may regulate star formation in dwarf galaxies even beyond the virial radii
of the MW and Andromeda. Caution is needed when comparing zoom-in simulations
targeting isolated dwarf galaxies against observed dwarf galaxies in the LG.Comment: Main text: 11 pages, 8 figures; appendices: 4 pages, 4 figures.
Submitted to MNRAS; comments welcom
A Silicon p-i-n detector for a hybrid CMOS imaging system
A fully depleted silicon p-i-n image sensor for a very low noise hybrid CMOS imaging system was simulated, fabricated, and electrically characterized. The image sensor was then bonded to the foundry fabricated CMOS circuitry to create the imaging system. SILVACO Atlas was used to simulate the steady state electrical operation of the device as well as the optical response. Revisions were made to an existing mask set to allow the use of both contact and projection lithography in the fabrication process. Significant process improvements were introduced to eliminate needless complexity and reduce leakage current from the previously reported 1.5x10-6 A/cm2 below the goal of 2.2x10-9 A/cm2. Following fabrication of the image sensors, electrical testing was performed to verify diode quality from leakage and lifetime measurements. A lift-off process was developed for thick metal layers used in the bump-bond hybridization process. Daisy-chain test parts were created to characterize the mechanical and electrical connections formed in the hybridization process. Fabricated p-i-n photodiode arrays were diced and hybridized to read-out integrated circuits using a flip-chip bump bond process with indium interconnects. Testing of hybridized devices is currently ongoing
Rainbow Trout (Oncorhynchus mykiss) Movement and Mortality in the Flat Brook-Roy Catch and Release Section of New Jersey
Rainbow trout are a widely distributed species for recreational angling. The state of New Jersey has 14 streams in which the Bureau of Freshwater Fisheries stocks hatchery raised Rainbow Trout. This paper focuses on the Flatbrook-Roy catch and release section of the Big Flat Brook in northwest NJ. From 2012 to 2015, electrofishing surveys conducted by the NJDEP reported significantly less fish within the Flatbrook-Roy catch and release area, compared to the state’s other catch and release area in the South Branch of the Raritan River. This study was designed to investigate and understand the fate of the trout introduced into the Flat Brook-Roy section by looking at their survivorship and movement in and/or out of the catch and release section of the stream. 79 fish were surgically implanted with radio transmitters and introduced into three separate stocking locations from April-September of 2017 and 2018. The data collected across the two years showed that the trout were not traveling outside of the catch and release designated waters. Across the summer months of each year, there was a 100% mortality rate within the sample, all credited to specific mammalian or avian predation events. Between the stocking sites, the trout both stayed longer and survived better at the site with the largest pool dimensions and most in-stream cover. The findings help fisheries management decisions by confirming that the introduced trout do in fact remain within the designated catch and release waters. Future decisions related to fish allocation and fishery regulation should consider stocking sites of adequate size that provide enough cover to increase survivorship and mitigate predation in order to maximize the recreational angling experience
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The Pseudoinflammatory Pattern Revisited
In 1973, Dr. Martin C. Mihm, Jr. presented the finding that congenital melanocytic nevi, when viewed at low magnification, resemble superficial and deep perivascular dermatitis, forming the so-called “pseudoinflammatory” pattern. One year earlier, Dr. Richard A. Sagebiel had put forward the concept of “pseudovascular spaces” in melanocytic nevi. A retrospective look at these early studies confirms that alert observation at the microscope can lead to a deeper understanding of the fundamental biology underlying melanocytic tumors
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