115 research outputs found
Influence of Water Mulches on Soil Temperatures and Sweet Corn and Green Bean Production
The relation between soil temperature and
crop production has been studied extensively.
Such studies resulted in a wide acceptance of
plastic mulches, asphalt mulches and other
practices designed to favorably alter the crop
environment.
Favorable qualities attributed to plastic
mulches are suppression of weed growth, reduction
of evaporation, and elevation of soil
temperatures early in the season. Experimental
evidence indicates the existence of optimum
soil temperature ranges for maximum crop
production. Wort (11), working under greenhouse
conditions, found maximum vegetive
production with Marquis wheat occurred at a
soil temperature of 72° F. Yamaguchi, et al.
(12), working with potatoes in the greenhouse,
reported that maximum foliar growth was in
the soil temperature range of 70 to 75° F.; the
optimum temperature range for tuber formation
was 60 to 75° F
Emergence and Yield of Beans Planted with a Seed-Oriented Planter
Recent observations from an unrelated bean (Phaseolus
vulgaris L.) field experiment indicated a possible relationship
between emergence and seed orientation. To
test the benefits of a "lay flat" orientation, a furrow opener
was developed that horizontally orients bean seeds at
uniform soil depths. Beans planted through this furrow
opener emerged through the soil crust sooner and in significantly
greater numbers than did those planted with
a standard two-disk furrow opener. Oriented and unoriented
plantings of dry and snap beans did not differ
in final total emergence. Nevertheless, early snap
bean yields were greater from the seed-oriented plots. Increased
yield was due to earlier emergence, and uniform
depth of planting. On uncrusted soil, seed orientation
did not significantly increase dry bean yield
Influence of Seed Orientation on Bean Seedling Emergence
Observation from an unrelated field bean experiment
indicated that certain seed orientations might reduce
emergence. Consequently, studies were initiated to determine
if orientation variations occur in planting and if
these variations influence emergence.
Orientation of bean seeds, dropped into both "V" and
flat-bottom furrows, were classified and tabulated. In
"V" furrows almost all orientations were possible; 36% assumed
the "lay-flat" orientation. In the flat-bottom furrow
85% of the beans were in the "lay-flat" position. The
influence of 11 different seed orientations on emergence
was evaluated in greenhouse studies. With crusted soils
seeds planted "hypocotyl end down" produced significantly
less emerged seedlings (1% level) and a lower emergence
rate. Orientation effects were observed to a lesser
degree in noncrusted soils.
The adverse influence of "hypocotyl end down" orientations
was attributed to seed rotation within the soil. For
controlled plantings the "lay-flat" orientation is recommended
due to both its high frequency of occurrence and
high emergence
A Simple Portable Reflectometer for Field Use
A small, portable, battery-powered field reflectometer,
which utilized an integrating sphere, was developed for
measuring reflectance from soils and intact leaves. Its
light source was a flashlight bulb; its wavelength selection
within the range of 0.4µ to 1.1µ was achieved
with interference filters. Comparison with laboratory
instruments was favorable
Trust schools and the politics of persuasion and the mobilisation of interest
This paper sets out the theoretical and methodological approach of a study of the politics of persuasion and the mobilisation of interest in relation to the Trust schools initiative in England. Drawing on the discourse theoretical approach of Laclau and Mouffe the paper argues that the politics of consensus associated with New Labour reconfigures the field of politics, closing down legitimate democratic space. Building on this approach and that of policy sociology the paper outlines how the researchers seeks to address the following questions – if the space for legitimate democratic debate is so severely constrained then how does a social democratic government deal with the kind of opposition that Labour faced in relation to Trust schools? How do governments persuade dissident citizens to support unpopular policies? How are citizens mobilised to support such policies? This also raises questions about how, in such a restricted political space, do those questioning or resisting such policies, engage in the politics of persuasion and the mobilisation of interests? The reconfiguration of the field of politics and what this means for the constitution of legitimate democratic debate is the object of study of the research
Possibility of an ultra-precise optical clock using the transition in Yb atoms held in an optical lattice
We report calculations designed to assess the ultimate precision of an atomic
clock based on the 578 nm transition in Yb atoms
confined in an optical lattice trap. We find that this transition has a natural
linewidth less than 10 mHz in the odd Yb isotopes, caused by hyperfine
coupling. The shift in this transition due to the trapping light acting through
the lowest order AC polarizability is found to become zero at the magic trap
wavelength of about 752 nm. The effects of Rayleigh scattering, higher-order
polarizabilities, vector polarizability, and hyperfine induced electronic
magnetic moments can all be held below a mHz (about a part in 10^{18}), except
in the case of the hyperpolarizability larger shifts due to nearly resonant
terms cannot be ruled out without an accurate measurement of the magic
wavelength.Comment: 4 pages, 1 figur
Novel Mutations in PTH1R Associated with Primary Failure of Eruption and Osteoarthritis
Autosomal dominant mutations in PTH1R segregate with primary failure of eruption (PFE), marked by clinical eruption failure of adult teeth without mechanical obstruction. While the diagnosis of PFE conveys a poor dental prognosis, there are no reports of PFE patients who carry PTH1R mutations and exhibit any other skeletal problems. We performed polymerase chain reaction–based mutational analysis of the PTH1R gene to determine the genetic contribution of PTH1R in 10 families with PFE. Sequence analysis of the coding regions and intron-exon boundaries of the PTH1R gene in 10 families (n = 54) and 7 isolated individuals revealed 2 novel autosomal dominant mutations in PTH1R (c.996_997insC and C.572delA) that occur in the coding region and result in a truncated protein. One family showed incomplete penetrance. Of 10 families diagnosed with PFE, 8 did not reveal functional (nonsynonymous) mutations in PTH1R; furthermore, 4 families and 1 sporadic case carried synonymous single-nucleotide polymorphisms. Five PFE patients in 2 families carried PTH1R mutations and presented with osteoarthritis. We propose that the autosomal dominant mutations of PTH1R that cause PFE may also be associated with osteoarthritis; a dose-dependent model may explain isolated PFE and osteoarthritis in the absence of other known symptoms in the skeletal system
Parenting through grief: A cross-sectional study of recently bereaved adults with minor children
Background: Grieving adults raising parentally-bereaved minor children experience persistently elevated symptoms of depression and grief. However, the factors associated with their mental health outcomes are not well understood. Aim: To investigate the psychosocial and demographic characteristics associated with grief distress and depressive symptom severity in bereaved adults with minor children. Design: Cross-sectional, web-based survey. Setting/participants: Eight hundred forty-five bereaved adults raising minor (age <18 years) children who had experienced the death of a co-parent. Primary outcomes were grief distress (Prolonged Grief Disorder-13), depressive symptoms (Patient-Reported Outcomes Measurement Information System-Depression), and widowed parenting self-efficacy (WPSES). Results: Mean grief scores were 33.5; mean depression scores were 58.3. Among the 690 individuals more than 6 months bereaved, 132 (19.3%) met criteria for prolonged grief disorder. In adjusted models, participants reporting higher grief scores were more recently bereaved, identified as mothers, non-Caucasian, had lower education and income, and had not anticipated their co-parent’s death. The statistical modeling results for depression scores were similar to grief scores except that depression was not associated with anticipation of co-parent death. Parents reporting lower WPSES scores had higher grief and depression scores. Retrospective assessments of more intense parenting worries at the time of co-parent death were also associated with higher grief and depression scores. Conclusions: For bereaved adults with minor children, unanticipated co-parent death was linked with higher grief distress but not symptoms of depression. Addressing parenting concerns may represent a common pathway for improving the mental health of parentally-bereaved families
E1 amplitudes, lifetimes, and polarizabilities of the low-lying levels of atomic ytterbium
The results of ab initio calculation of E1 amplitudes, lifetimes,and
polarizabilities for several low-lying levels of ytterbium are reported. The
effective Hamiltonian for the valence electrons has been constructed in the
frame of CI+MBPT method and solutions of many electron equation are found.Comment: 11 pages, submitted to Phys.Rev.
Separate and combined effects of advanced age and obesity on mammary adipose inflammation, immunosuppression and tumor progression in mouse models of triple negative breast cancer
Introduction: Advanced age and obesity are independent risk and progression factors for triple negative breast cancer (TNBC), which presents significant public health concerns for the aging population and its increasing burden of obesity. Due to parallels between advanced age- and obesityrelated biology, particularly adipose inflammation, we hypothesized that advanced age and obesity each accelerate mammary tumor growth through convergent, and likely interactive, mechanisms. Methods: To test this hypothesis, we orthotopically transplanted murine syngeneic TNBC cells into the mammary glands of young normoweight control (7 months), young diet-induced obese (DIO), aged normoweight control (17 months), and aged DIO female C57BL/6J mice. Results: Here we report accelerated tumor growth in aged control and young DIO mice, compared with young controls. Transcriptional analyses revealed, with a few exceptions, overlapping patterns of mammary tumor inflammation and tumor immunosuppression in aged control mice and young DIO mice, relative to young controls. Moreover, aged control and young DIO tumors, compared with young controls, had reduced abundance ofcytotoxic CD8 T cells. Finally, DIO in advanced age exacerbated mammary tumor growth, inflammation and tumor immunosuppression. Discussion: These findings demonstrate commonalities in the mechanisms driving TNBC in aged and obese mice, relative to young normoweight controls. Moreover, we found that advanced age and DIO interact to accelerate mammary tumor progression. Given the US population is getting older and more obese, age- and obesity-related biological differences will need to be considered when developing mechanism-based strategies for preventing or controlling breast cancer
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