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Search Results: 1 - 10 of 17887 matches for " Mark Goldblatt "
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A Patchy Cloud Model for the L to T Dwarf Transition
Mark S. Marley,Didier Saumon,Colin Goldblatt
Physics , 2010, DOI: 10.1088/2041-8205/723/1/L117
Abstract: One of the mechanisms suggested for the L to T dwarf spectral type transition is the appearance of relatively cloud-free regions across the disk of brown dwarfs as they cool. The existence of partly cloudy regions has been supported by evidence for variability in dwarfs in the late L to early T spectral range, but no self-consistent atmosphere models of such partly cloudy objects have yet been constructed. Here we present a new approach for consistently modeling partly cloudy brown dwarfs and giant planets. We find that even a small fraction of cloud holes dramatically alter the atmospheric thermal profile, spectra, and photometric colors of a given object. With decreasing cloudiness objects briskly become bluer in J - K and brighten in J band, as is observed at the L/T transition. Model spectra of partly cloudy objects are similar to our models with globally homogenous, but thinner, clouds. Hence spectra alone may not be sufficient to distinguish partial cloudiness although variability and polarization measurements are potential observational signatures. Finally we note that partial cloud cover may be an alternative explanation for the blue L dwarfs.
Short-Term Psychodynamic Psychotherapy in Patients with “Male Depression” Syndrome, Hopelessness, and Suicide Risk: A Pilot Study
Gloria Angeletti,Maurizio Pompili,Marco Innamorati,Chiara Santucci,Valeria Savoja,Mark Goldblatt,Paolo Girardi
Depression Research and Treatment , 2013, DOI: 10.1155/2013/408983
Abstract: Objectives and Methods. This was an observational study of the efficacy of short-term psychodynamic psychotherapy (STPP) in a sample of 35 (30 women and 5 men) patients with moderate-to-severe “male depression” (Gotland Scale for Male Depression (GSMD)?≥?13) comorbid with unipolar mood disorder (dysthymia and major depression) or anxiety disorder. Outcome measures were GSMD and BHS (Beck Hopelessness Scale) score changes from baseline. Results. Patients had a strong response to STPP on the GSMD (estimated mean score change ; partial eta squared?? ), but not on the BHS (estimated mean score change ; partial eta squared ? ). BHS score changes were significantly associated with GSMD score changes (Pearson's ; ), even when controlling for the severity of hopelessness at the baseline (partial ; ). Conclusions. STPP proved to be effective in patients suffering from “male depression” although hopelessness was only marginally reduced by this treatment which points to the need to better understand how STPP can be involved in the reduction of suicide risk. 1. Introduction The term “depression” encompasses a wide range of conditions that may occur along a continuum, ranging from milder forms of discomfort to more severe and persistent form, as in the case of major depression. Depression is the leading cause of disability and the 4th leading contributor to the global burden of disease [1, 2] and by the year 2020, it is projected to become the 2nd leading contributor to the global burden of disease in all ages and both sexes [1]. Major depression is the most frequent mental illness in the world [3–6]. For example, in the US, the Epidemiological Catchment Area (ECA) Study indicated a one-month prevalence between 1.7% and 3.4% [7], and more recently, the National Comorbidity Survey Replication (NCS-R) estimated a 12-month prevalence of 6.6% [8]. Nevertheless, prevalence of moderate- to- severe depressive symptoms could be much higher [9–11]. In 2010, the British National Institute for Health and Clinical Excellence (NICE) commissioned the development of an updated version of the guideline on the treatment and management of depression in adults [12]. The NICE guideline pointed out that people who suffer from depression usually prefer psychological treatments to medication [13] and value outcomes beyond symptom reduction [14]. The NICE guideline indicated that it was not possible to demonstrate a consistent picture of any clinically important benefit for short-term psychodynamic psychotherapy (STPP) in depression. While cognitive-behavioral therapy and interpersonal
PHYLOGENY AND CLASSIFICATION OF THE IRIDACEAE AND THE RELATIONSHIPS OF IRIS
P. GOLDBLATT
Annali di Botanica , 2000,
Abstract: Iridaceae are a well defined family of some 1800 species and between 60 and 70 genera. Molecular studies of chloroplast DNA has confirmed the position of the family in the order Asparagales, contrary to earlier work that placed the Iridaceae in Liliales. The family comprises two large assemblages of species, currently regarded as subfamilies Ixioideae and Iridaceae. The relationships of the remaining seven genera, included in subfamilies Isophysidoideae and Nivenioideae, have been rendered uncertain because of the lack of congruence between molecular and morphological studies using different outgroups and/or different data sets. Ixioideae, the largest subfamily, comprises more than half the total species in the family. Largely African, with fair representation in Eurasia, the generic phylogeny of Ixioideae is poorly understood. Most genera exhibit a considerable range of floral diversity based on floral zygomorphy and the elaboration or reduction of the perianth tube. Production of floral nectar and pollination by long-tongued insects including anthophorine bees, Lepidoptera, longproboscid flies and birds is a recurring theme but reversals to actinomorphy, often accompanied by the suppression of nectar production, has occurred in species of several genera that are pollinated by hopliine beetles. Virtually worldwide in distribution, Iridoideae comprise five tribes, the Australian Diplarrheneae, the Australasian and American Sisyrinchieae, the exclusively American Trimezieae (= Mariceae) and Tigridieae, and the Old World Irideae. Iris and Moraea constitute the major genera of this last tribe, Iris a North Temperate genus and Moraea largely sub-Saharan African. Several small genera allied to Iris or Moraea are believed to have flowers modified for different pollination strategies and have been shown by molecular data to be nested with one or other of the larger genera. Vegetative diversity, especially in the leaf and rootstock, is an important variable in Iris whereas floral divergence and vegetative uniformity characterize Moraea. Genera of Irideae appear to be primarily adapted for pollination by bees foraging for nectar and pollen transfer is passive. Specialization has shifted the pollination strategy either to a generalist system using flies, bees and beetles, or a specialist system using bees foraging for pollen, or carrion flies attracted to foul odors, or hopliine beetles that use flowers as sites for assembly and mating.
Habitability of waterworlds: runaway greenhouses, atmospheric expansion and multiple climate states of pure water atmospheres
Colin Goldblatt
Physics , 2015, DOI: 10.1089/ast.2014.1268
Abstract: There are four different stable climate states for pure water atmospheres, as might exist on so-called "waterworlds". I map these as a function of solar constant for planets ranging in size from Mars size to 10 Earth-mass. The states are: globally ice covered (Ts< 245K), cold and damp (270 < Ts< 290K), hot and moist (350< Ts< 550K) and very hot and dry (Ts< 900K). No stable climate exists for 290< Ts < 350K or 550 < Ts < 900K. The union of hot moist and cold damp climates describe the liquid water habitable zone, the width and location of which depends on planet mass. At each solar constant, two or three different climate states are stable. This is a consequence of strong non-linearities in both thermal emission and the net absorption of sunlight. Across the range of planet sizes, I account for the atmospheres expanding to high altitudes as they warm. The emitting and absorbing surfaces (optical depth of unity) move to high altitude, making their area larger than the planet surface, so more thermal radiation is emitted and more sunlight absorbed (the former dominates). The atmospheres of small planets expand more due to weaker gravity: the effective runaway greenhouse threshold is about 35Wm-2 higher for Mars, 10Wm-2 higher for Earth or Venus but only a few Wm-2 higher for a 10 Earth-mass planet. There is an underlying (expansion neglected) trend of increasing runaway greenhouse threshold with planetary size (40Wm-2 higher for a 10 Earth-mass planet than for Mars). Summing these opposing trends means that Venus-size (or slightly smaller) planets are most susceptible to a runaway greenhouse. The habitable zone for pure water atmospheres is very narrow, with an insolation range of 0.07 times the solar constant. A wider habitable zone requires background gas and greenhouse gas; N2 and CO2 on Earth, which are biologically controlled. Thus, habitability depends on inhabitance.
Overview of Intervention Programs for Parents of Young Children (0 - 6)  [PDF]
Merav Goldblatt, Rivka Yahav, Tsameret Ricon
Open Journal of Pediatrics (OJPed) , 2014, DOI: 10.4236/ojped.2014.43026
Abstract:

In most of the world’s societies and cultures, the biological mother and father bear primary responsibility to care for their child’s needs and to guide him or her through the process of entry into society [1]. The parent serves, for the most part, as the significant figure with the greatest amount of influence over the child’s life. Through his parent, the child learns the skills necessary to experience the world and function in it, whether the skills are in relation to survival needs such as eating, washing and mobility or developmental and social needs such as forming social relationships and developing the capacity to think and learn through play and supervision [2]. Thus the parent plays a critical but complex role in the development of his or her child, a role that requires development of a wide range of new behavioral, communicational, cognitive and emotional skills and capabilities in order to understand and cope with the challenges of child-rearing. Similarly, parenting styles and characteristics are influenced by a number of variables: The parent, the child, the interaction between them, and environmental variables such as culture, socio-economic status, and the existing family unit [2]

Aerobiology and Its Role in the Transmission of Infectious Diseases
Aaron Fernstrom,Michael Goldblatt
Journal of Pathogens , 2013, DOI: 10.1155/2013/493960
Abstract:
Aerobiology and Its Role in the Transmission of Infectious Diseases
Aaron Fernstrom,Michael Goldblatt
Journal of Pathogens , 2013, DOI: 10.1155/2013/493960
Abstract: Aerobiology plays a fundamental role in the transmission of infectious diseases. As infectious disease and infection control practitioners continue employing contemporary techniques (e.g., computational fluid dynamics to study particle flow, polymerase chain reaction methodologies to quantify particle concentrations in various settings, and epidemiology to track the spread of disease), the central variables affecting the airborne transmission of pathogens are becoming better known. This paper reviews many of these aerobiological variables (e.g., particle size, particle type, the duration that particles can remain airborne, the distance that particles can travel, and meteorological and environmental factors), as well as the common origins of these infectious particles. We then review several real-world settings with known difficulties controlling the airborne transmission of infectious particles (e.g., office buildings, healthcare facilities, and commercial airplanes), while detailing the respective measures each of these industries is undertaking in its effort to ameliorate the transmission of airborne infectious diseases. 1. Introduction Exposure to airborne pathogens is a common denominator of all human life [1]. With the improvement of research methods for studying airborne pathogens has come evidence indicating that microorganisms (e.g., viruses, bacteria, and fungal spores) from an infectious source may disperse over very great distances by air currents and ultimately be inhaled, ingested, or come into contact with individuals who have had no contact with the infectious source [2–5]. Airborne pathogens present a unique challenge in infectious disease and infection control, for a small percentage of infectious individuals appear to be responsible for disseminating the majority of infectious particles [6]. This paper begins by reviewing the crucial elements of aerobiology and physics that allow infectious particles to be transmitted via airborne and droplet means. Building on the basics of aerobiology, we then explore the common origins of droplet and airborne infections, as these are factors critical to understanding the epidemiology of diverse airborne pathogens. We then discuss several environmental considerations that influence the airborne transmission of disease, for these greatly impact particular environments in which airborne pathogens are commonly believed to be problematic. Finally, we discuss airborne pathogens in the context of several specific examples: healthcare facilities, office buildings, and travel and leisure settings (e.g.,
Radiative forcings for 28 potential Archean greenhouse gases
Brendan Byrne,Colin Goldblatt
Physics , 2014, DOI: 10.5194/cpd-10-2011-2014
Abstract: Despite reduced insolation in the late Archean, evidence suggests a warm climate which was likely sustained by a stronger greenhouse effect, the so-called Faint Young Sun Problem (FYSP). CO2 and CH4 are generally thought to be the mainstays of this enhanced greenhouse, though many other gases have been proposed. We present high accuracy radiative forcings for CO2, CH4 and 26 other gases, performing the radiative transfer calculations at line-by-line resolution and using HITRAN 2012 line data for background pressures of 0.5, 1, and 2 bar of atmospheric N2. For CO2 to resolve the FYSP alone at 2.8 Gyr BP (80% of present solar luminosity), 0.32 bar is needed with 0.5 bar of atmospheric N2, 0.20 bar with 1 bar of atmospheric N2, or 0.11 bar with 2 bar of atmospheric N2. For CH4, we find that near-infrared absorption is much stronger than previously thought, arising from updates to the HITRAN database. CH4 radiative forcing peaks at 10.3, 9, or 8.3 Wm-2 for background pressures of 0.5, 1 or 2 bar, likely limiting the utility of CH4 for warming the Archean. For the other 26 HITRAN gases, radiative forcings of up to a few to 10 Wm-2 are obtained from concentrations of 0.1-1 ppmv for many gases. For the 20 strongest gases, we calculate the reduction in radiative forcing due to overlap. We also tabulate the modern sources, sinks, concentrations and lifetimes of these gases and summaries the literature on Archean sources and concentrations. We recommend the forcings provided here be used both as a first reference for which gases are likely good greenhouse gases, and as a standard set of calculations for validation of radiative forcing calculations for the Archean.
The Nitrogen Budget of Earth
Ben Johnson,Colin Goldblatt
Physics , 2015, DOI: 10.1016/j.earscirev.2015.05.006
Abstract: We comprehensively compile and review N content in geologic materials to calculate a new N budget for Earth. Using analyses of rocks and minerals in conjunction with N-Ar geochemistry demonstrates that the Bulk Silicate Earth (BSE) contains \sim7\pm4 times present atmospheric N (4\times10^18 kg N, PAN), with 27\pm16\times10^18 kg N. Comparison to chondritic composition, after subtracting N sequestered into the core, yields a consistent result, with BSE N between 17\pm13\times10^18 kg to 31\pm24\times10^18 kg N. In the chondritic comparison we calculate a N mass in Earth's core (180\pm110 to 300\pm180\times10^18 kg) and discuss the Moon as a proxy for the early mantle. Significantly, we find the majority of the planetary budget of N is in the solid Earth. The N estimate herein precludes the need for a "missing N" reservoir. Nitrogen-Ar systematics in mantle rocks and basalts identify two mantle reservoirs: MORB-source like (MSL) and high-N. High-N mantle is composed of young, N-rich material subducted from the surface and is identified in OIB and some xenoliths. In contrast, MSL appears to be made of old material, though a component of subducted material is evident in this reservoir as well. Using our new budget, we calculate a {\delta}15N value for BSE plus atmosphere of \sim2\permil. This value should be used when discussing bulk Earth N isotope evolution. Additionally, our work indicates that all surface N could pass through the mantle over Earth history, and the mantle may act as a long-term sink for N. Since N acts as a tracer of exchange between the atmosphere, oceans, and mantle over time, clarifying its distribution in the Earth is critical for evolutionary models concerned with Earth system evolution. We suggest that N be viewed in the same vein as carbon: it has a fast, biologically mediated cycle which connects it to a slow, tectonically-controlled geologic cycle.
Well structured program equivalence is highly undecidable
Robert Goldblatt,Marcel Jackson
Mathematics , 2011,
Abstract: We show that strict deterministic propositional dynamic logic with intersection is highly undecidable, solving a problem in the Stanford Encyclopedia of Philosophy. In fact we show something quite a bit stronger. We introduce the construction of program equivalence, which returns the value $\mathsf{T}$ precisely when two given programs are equivalent on halting computations. We show that virtually any variant of propositional dynamic logic has $\Pi_1^1$-hard validity problem if it can express even just the equivalence of well-structured programs with the empty program \texttt{skip}. We also show, in these cases, that the set of propositional statements valid over finite models is not recursively enumerable, so there is not even an axiomatisation for finitely valid propositions.
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