208 research outputs found
Restoring Burnout Millenial Ministry Leaders within a Western North American Digital Society
A growing number of emerging Millennial leaders between the ages of 22 and 35 are burning out, leaving ministry, and subsequently not returning. Emotional drain, physical fatigue, and an underdeveloped formation mark these individuals. My research studies the digital age and it\u27s unique impact on Millennial burnout and the subsequent leaving of ministry. Spiritual formation is offered as a corrective and preventative lifestyle, while simultaneously being important to the restoring of young burnt out ministry leaders. Section 1 describes the landscape of burnout among Millennial leaders, highlighting the emerging generation and their unique relationship with burnout. Section 2 surveys burnout care solutions from five distinct domains of research and care, highlighting strengths and weaknesses from each domain. Section 3 defines spiritual formation and its unique contribution in creating a new formational vision for Millennial leaders. Sections 4 and 5 outline the specifications of a non-fiction book addressing the problem of burnout in Millennials, called On: The Paradox of Digital Presence and Burnout Among Millennials. Section 6 offers a postscript citing further areas of research which may be explored. The Artifact itself is a non-fiction book manuscript intended to create a new formational vision for Millennial leaders in the Digital Age
Searching for z~7.7 Lyman Alpha Emitters in the COSMOS Field with NEWFIRM
The study of Ly-alpha emission in the high-redshift universe is a useful
probe of the epoch of reionization, as the Ly-alpha line should be attenuated
by the intergalactic medium (IGM) at low to moderate neutral hydrogen
fractions. Here we present the results of a deep and wide imaging search for
Ly-alpha emitters in the COSMOS field. We have used two ultra-narrowband
filters (filter width of ~8-9 {\deg}A) on the NEWFIRM camera, installed on the
Mayall 4m telescope at Kitt Peak National Observatory, in order to isolate
Ly-alpha emitters at z = 7.7; such ultra-narrowband imaging searches have
proved to be excellent at detecting Ly-alpha emitters. We found 5-sigma
detections of four candidate Ly-alpha emitters in a survey volume of 2.8 x 10^4
Mpc^3 (total survey area ~760 arcmin^2). Each candidate has a line flux greater
than 8 x 10^-18 erg s^-1 cm^-2. Using these results to construct a luminosity
function and comparing to previously established Ly-alpha luminosity functions
at z = 5.7 and z = 6.5, we find no conclusive evidence for evolution of the
luminosity function between z = 5.7 and z = 7.7. Statistical Monte Carlo
simulations suggest that half of these candidates are real z = 7.7 targets, and
spectroscopic follow-up will be required to verify the redshift of these
candidates. However, our results are consistent with no strong evolution in the
neutral hydrogen fraction of the IGM between z = 5.7 and z = 7.7, even if only
one or two of the z = 7.7 candidates are spectroscopically confirmed.Comment: 29 pages, 5 figures, accepted to ApJ (12/11
Growth and predation activity at deep-sea hydrothermal vents along the Galápagos Rift
Growth rates of unclassified mussels collected from hydrothermal vents on the Pacific Ocean (2500 m) are among the highest recorded for deep-sea species. Mature mussels have mean growth rates of about 1 cm yr-1 which are comparable to growth rates of shallow water mussels...
Understanding the redshift evolution of the luminosity functions of Lyman-alpha emitters
We present a semi-analytical model of star formation which explains
simultaneously the observed UV luminosity function of high redshift Lyman break
galaxies (LBGs) and luminosity functions of Lyman-alpha emitters. We consider
both models that use the Press-Schechter (PS) and Sheth-Tormen (ST) halo mass
functions to calculate the abundances of dark matter halos. The Lyman-alpha
luminosity functions at z < 4 are well reproduced with only <10% of the LBGs
emitting Lyman-alpha lines with rest equivalent width greater than the limiting
equivalent width of the narrow band surveys. However, the observed luminosity
function at z > 5 can be reproduced only when we assume that nearly all LBGs
are Lyman-alpha emitters. Thus it appears that 4 < z < 5 marks the epoch when a
clear change occurs in the physical properties of the high redshift galaxies.
As Lyman-alpha escape depends on dust and gas kinematics of the inter stellar
medium (ISM), this could mean that on an average the ISM at z > 5 could be less
dusty, more clumpy and having more complex velocity field. All of these will
enable easier escape of the Lyman-alpha photons. At z > 5 the observed
Lyman-alpha luminosity function are well reproduced with the evolution in the
halo mass function along with very minor evolution in the physical properties
of high redshift galaxies. In particular, upto z = 6.5, we do not see the
effect of evolving inter galactic medium (IGM) opacity on the Lyman-alpha
escape from these galaxies.Comment: 9 pages, 4 figures, 2 tables, Accepted for publication in MNRA
Keck Spectroscopy of Faint 3<z<7 Lyman Break Galaxies: - I. New constraints on cosmic reionisation from the luminosity and redshift-dependent fraction of Lyman-alpha emission
We present results from a new Keck spectroscopic survey of UV-faint LBGs in
the redshift range 3<z<7. Combined with earlier Keck and published ESO VLT
data, our sample contains more than 600 dropouts, offering new insight into the
nature of sub-L* sources typical of those likely to dominate the cosmic
reionisation process. Here we use this sample to characterise the fraction of
strong Lya emitters within the continuum-selected dropouts. By quantifying how
the "Lya fraction" varies with redshift, we seek to constrain changes in Lya
transmission associated with reionisation. In order to distinguish the effects
of reionisation from other factors which affect the Lya fraction (e.g. dust,
ISM kinematics), we study the luminosity and redshift-dependence of the Lya
fraction over 3<z<6, when the IGM is known to be ionised. These results reveal
that low luminosity galaxies show strong Lya emission much more frequently than
luminous systems, and that at fixed luminosity, the prevalence of strong Lya
emission increases moderately with redshift over 3 < z < 6. Based on the
correlation between blue UV slopes and strong Lya emitting galaxies in our
dataset, we argue that the Lya fraction trends are governed by redshift and
luminosity-dependent variations in the dust obscuration, with likely additional
contributions from trends in the kinematics and covering fraction of neutral
hydrogen. We find a tentative decrease in the Lya fraction at z~7 based on the
limited IR spectra for candidate z~7 lensed LBGs, a result which, if confirmed
with future surveys, would suggest an increase in the neutral fraction by this
epoch. Given the supply of z and Y-drops now available from Hubble WFC3/IR
surveys, we show it will soon be possible to significantly improve estimates of
the Lya fraction using optical and near-IR spectrographs, thereby extending the
study conducted in this paper to 7<z<8.Comment: 23 pages, 15 figures, submitted to MNRA
A Robust Determination of the Time Delay in 0957+561A,B and a Measurement of the Global Value of Hubble's Constant
Photometric monitoring of the gravitational lens system 0957+561A,B in the g
and r bands with the Apache Point Observatory (APO) 3.5 m telescope during 1996
shows a sharp g band event in the trailing (B) image light curve at the precise
time predicted from the observation of an event during 1995 in the leading (A)
image with a delay of 415 days. This success confirms the "short delay," and
the lack of any feature at a delay near 540 days rejects the "long delay" for
this system, resolving a long-standing controversy. A series of statistical
analyses of our light curve data yield a best fit delay of 417 +/- 3 days (95%
confidence interval). Recent improvements in the modeling of the lens system
(consisting of a galaxy and cluster) allow us to derive a value of the global
(at z = 0.36) value of Hubble's constant H_0 using Refsdal's method, a simple
and direct distance determination based on securely understood physics and
geometry. The result is H_0 = 63 +/- 12 km/s/Mpc (for Omega = 1) where this 95%
confidence interval is dominated by remaining lens model uncertainties.Comment: accepted by ApJ, AASTeX 4.0 preprint, 4 PostScript figure
Spitzer Imaging of i'-drop Galaxies: Old Stars at z~6
We present new evidence for mature stellar populations with ages >100Myr in
massive galaxies (M_stellar>10^10M_sun) seen at a time when the Universe was
less than 1Gyr old. We analyse the prominent detections of two z~6 star-forming
galaxies (SBM03#1 & #3) made at wavelengths corresponding to the rest-frame
optical using the IRAC camera onboard the Spitzer Space Telescope. We had
previously identified these galaxies in HST/ACS GOODS images of Chandra Deep
Field South through the "i-drop" Lyman break technique, and subsequently
confirmed spectroscopically with the Keck telescope. The new Spitzer photometry
reveals significant Balmer/4000Ang discontinuities, indicative of dominant
stellar populations with ages >100Myr. Fitting a range of population synthesis
models (for normal initial mass functions) to the HST/Spitzer photometry yields
ages of 250-650Myr and implied formation redshifts z~7.5-13.5 in
presently-accepted world models. Remarkably, our sources have best-fit stellar
masses of 1.3-3.8x10^10M_sun (95% confidence) assuming a Salpeter initial mass
function. This indicates that at least some galaxies with stellar masses >20%
of those of a present-day L* galaxy had already assembled within the first Gyr
after the Big Bang. We also deduce that the past average star formation rate
must be comparable to the current observed rate (SFR_UV~5-30M_sun/yr),
suggesting that there may have been more vigorous episodes of star formation in
such systems at higher redshifts. Although a small sample, limited primarily by
Spitzer's detection efficiency, our result lends support to the hypothesis
advocated in our earlier analyses of the Ultra Deep Field and GOODS HST/ACS
data. The presence of established systems at z~6 suggests long-lived sources at
earlier epochs (z>7) played a key role in reionizing the Universe.Comment: Accepted for publication in MNRAS (minor corrections made
Examples of Risk Tools for Pests in Peanut (Arachis hypogaea) Developed for Five Countries Using Microsoft Excel
Suppressing pest populations below economically-damaging levels is an important element of sustainable peanut (Arachis hypogaea L.) production. Peanut farmers and their advisors often approach pest management with similar goals regardless of where they are located. Anticipating pest outbreaks using field history and monitoring pest populations are fundamental to protecting yield and financial investment. Microsoft Excel was used to develop individual risk indices for pests, a composite assessment of risk, and costs of risk mitigation practices for peanut in Argentina, Ghana, India, Malawi, and North Carolina (NC) in the United States (US). Depending on pests and resources available to manage pests, risk tools vary considerably, especially in the context of other crops that are grown in sequence with peanut, cultivars, and chemical inputs. In Argentina, India, and the US where more tools (e.g., mechanization and pesticides) are available, risk indices for a wide array of economically important pests were developed with the assumption that reducing risk to those pests likely will impact peanut yield in a positive manner. In Ghana and Malawi where fewer management tools are available, risks to yield and aflatoxin contamination are presented without risk indices for individual pests. The Microsoft Excel platform can be updated as new and additional information on effectiveness of management practices becomes apparent. Tools can be developed using this platform that are appropriate for their geography, environment, cropping systems, and pest complexes and management inputs that are available. In this article we present examples for the risk tool for each country.Instituto de PatologĂa VegetalFil: Jordan, David L. North Carolina State University. Department of Crop and Soil Sciences; Estados UnidosFil: Buol, Greg S. North Carolina State University. Department of Crop and Soil Sciences; Estados UnidosFil: Brandenburg, Rick L. North Carolina State University. Department of Entomology and Plant Pathology; Estados UnidosFil: Reisig, Dominic. North Carolina State University. Department of Entomology and Plant Pathology; Estados UnidosFil: Nboyine, Jerry. Council for Scientific and Industrial Research. Savanna Agricultural Research Institute; GhanaFil: Abudulai, Mumuni. Council for Scientific and Industrial Research. Savanna Agricultural Research Institute; GhanaFil: Oteng-Frimpong, Richard.Council for Scientific and Industrial Research. Savanna Agricultural Research Institute; GhanaFil: Brandford Mochiah, Moses.Council for Scientific and Industrial Research. Crops Research Institute; GhanaFil: Asibuo, James Y. Council for Scientific and Industrial Research. Crops Research Institute; GhanaFil: Arthur, Stephen. Council for Scientific and Industrial Research. Crops Research Institute; GhanaFil: Paredes, Juan AndrĂ©s. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Unidad de FitopatologĂa y ModelizaciĂłn AgrĂcola (UFyMA); ArgentinaFil: Paredes, Juan AndrĂ©s. Instituto Nacional de TecnologĂa Agropecuaria (INTA). Instituto de PatologĂa Vegetal; ArgentinaFil: Monguillot, JoaquĂn Humberto. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Unidad de FitopatologĂa y ModelizaciĂłn AgrĂcola (UFyMA); ArgentinaFil: Monguillot, JoaquĂn Humberto. Instituto Nacional de TecnologĂa Agropecuaria (INTA). Instituto de PatologĂa Vegetal; ArgentinaFil: Rhoads, James. University of Georgia. Feed the Future Innovation Lab for Peanut; Estados Unido
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