1,945 research outputs found
Bioassay of milk for estrogen content from stilbestrol-treated and non-treated cows
Call number: LD2668 .T4 1956 B37Master of Scienc
Characterization of the Marine Fish Assemblage Associated with the Nearshore Hardbottom of Broward County, Florida, USA
Some shallow (\u3c7 m, water depth) nearshore hardbottom areas of southeast Florida have been reported to function as important juvenile fish habitat. Much of this area has been impacted by one or more local beach renourishments (sand fill to offset erosion). We characterized the nearshore fish communities and compared the fish assemblages adjacent to renourished beach to those adjacent to never-renourished beach along a 30-km stretch of coastline, primarily in Broward County, using three visual census methods. Two hundred transect-counts, 100 point-counts and 98 rover-diver counts were completed during JuneâAugust 2001. In transect- and point-counts, abundance of all fish species and their sizes were recorded; the rover-diver counts consisted of a simple species list. In total, 164 species and over 72,000 fish were recorded. The highest number of species (145) was recorded with the rover-diver counts. The transects-counts had 118 species and 109 species were recorded on the point-counts. With either all the sites adjacent to renourished beach pooled and compared to the pooled never-renourished sites or individual comparisons amongst renourished and neighboring never-renourished sites, no consistent differences were noted in fish abundance or species richness (ANOVA) or among fish assemblage structure (MDS plot of BrayâCurtis dissimilarity indices). However, although the data show no obvious distinct difference between the renourished and never-renourished sites, due to several important confounding factors (e.g., census methodology, longshore movement of sand fill) and the absence of baseline data prior to any renourishment, it would be premature to translate these results into management strategies. The assemblage structure, in terms of percentage of juvenile fish (\u3c5 cm) as well as percent contributions by family, was similar for the point-counts and transect-counts. However, in mean density per m2 of substrate, greater abundance and greater species richness values were recorded with the transect-counts than with the point-counts. Newly settled and early juveniles were the dominant component (\u3e84%) of the inshore fish community, consisting primarily (\u3e90%) of grunts (Haemulidae). After the grunts, the wrasses (Labridae) at about 5%, and damselfish (Pomacentridae) at roughly 2% were the predominant families. It is clear from this study and others that the nearshore hardbottom of Broward County is an important juvenile fish habitat, especially for grunts. However, the nearshore hardbottom does not appear to be obligate habitat for these fishes as fishes associated with this area are, apparently, not unique to the nearshore hardbottom either in species or ontogenic stage
Peste des Petits Ruminants infection among cattle and wildlife in Northern Tanzania
We investigated peste des petits ruminants (PPR) infection in cattle and wildlife in northern Tanzania. No wildlife from protected ecosystems were seropositive. However, cattle from villages where an outbreak had occurred among small ruminants showed high PPR seropositivity, indicating that spillover infection affects cattle. Thus, cattle could be of value for PPR serosurveillance
Strategic toolkits: seniority, usage and performance in the German SME machinery and equipment sector
This paper examines the strategic tool kit, from a human resource management (HRM) perspective, in terms of usage and impact. Research to date has tended to consider usage, assuming to a certain extent that knowledge and understanding of particular tools suggest that practitioners value them. The research on which this paper is based builds upon the idea that usage indicates satisfaction, but develops the usage theme to investigate which decision-makers are actually engaged in both tool appliance and the strategic process. Of particular interest to the researchers are the educational background, age and seniority of the decision-makers. In addition, potential links with HRM and organizational performance are also explored. The context of the research, the German machinery and equipment sector, provides an insight into the industry's ability to sustain growth in face of increasing international competition. The paper calls for a greater awareness, from a human resource perspective, and utilization of strategic management practice and associated decision-making aids
Calcium supplements and risk of CVD: A meta-analysis of randomized trials
Background: Vitamin D supplements may only be beneficial for the prevention of osteoporotic fractures when administered with calcium and in individuals with low blood levels of 25(OH)D, but possible hazards of calcium supplements on CVD cannot be excluded. Objectives: We conducted a meta-analysis of all placebo-controlled randomized trials assessing the effects of calcium supplements alone or with vitamin D on CHD, stroke, and all-cause mortality. Methods: A meta-analysis of 11 trials included 7 comparisons of calcium alone compared with control (n = 8634) and 6 comparisons of calcium plus vitamin D compared with control (n = 46,804). Aggregated study-level data were obtained from individual trials and combined using a fixed-effects meta-analysis. The main outcomes included MI, CHD death, any CHD, stroke, and all-cause mortality. Results: Among trials of calcium alone (mean daily dose 1 g), calcium was not significantly associated with any excess risk of MI (RR, 1.15; 95% CI: 0.88, 1.51; n = 219 events), CHD death (RR, 1.24; 95% CI: 0.89, 1.73; n = 142), any CHD (RR, 1.01; 95% CI: 0.75, 1.37; n = 177), or stroke (RR, 1.15; 95% CI, 0.90, 1.46, n = 275). Among 6 trials of combined treatment, supplementation with calcium plus vitamin D was not significantly associated with any excess risk of MI (RR, 1.09; 95% CI: 0.95, 1.25; n = 854), CHD death (RR, 1.04; 95% CI: 0.85, 1.27; n = 391), any CHD (RR, 1.05; 95% CI: 0.93, 1.19; n = 1061), or stroke (RR, 1.02; 95% CI: 0.89, 1.17; n = 885). Likewise, calcium alone, or with vitamin D had no significant associations with all-cause mortality. Conclusions: This meta-analysis demonstrated that calcium supplements were not associated with any significant hazard for CHD, stroke, or all-cause mortality and excluded excess risks above 0.3%â0.5% per year for CHD or stroke. Further trials of calcium and vitamin D are required in individuals with low blood levels of 25(OH)D for the prevention of fracture and other disease outcomes
Type II Supernovae as Probes of Cosmology
- Constraining the cosmological parameters and understanding Dark Energy have
tremendous implications for the nature of the Universe and its physical laws.
- The pervasive limit of systematic uncertainties reached by cosmography
based on Cepheids and Type Ia supernovae (SNe Ia) warrants a search for
complementary approaches.
- Type II SNe have been shown to offer such a path. Their distances can be
well constrained by luminosity-based or geometric methods. Competing,
complementary, and concerted efforts are underway, to explore and exploit those
objects that are extremely well matched to next generation facilities.
Spectroscopic follow-up will be enabled by space- based and 20-40 meter class
telescopes.
- Some systematic uncertainties of Type II SNe, such as reddening by dust and
metallicity effects, are bound to be different from those of SNe Ia. Their
stellar progenitors are known, promising better leverage on cosmic evolution.
In addition, their rate - which closely tracks the ongoing star formation rate
- is expected to rise significantly with look- back time, ensuring an adequate
supply of distant examples.
- These data will competitively constrain the dark energy equation of state,
allow the determination of the Hubble constant to 5%, and promote our
understanding of the processes involved in the last dramatic phases of massive
stellar evolution.Comment: Science white paper, submitted to the Decadal committee Astro201
Type II-P Supernovae from the SDSS-II Supernova Survey and the Standardized Candle Method
We apply the Standardized Candle Method (SCM) for Type II Plateau supernovae
(SNe II-P), which relates the velocity of the ejecta of a SN to its luminosity
during the plateau, to 15 SNe II-P discovered over the three season run of the
Sloan Digital Sky Survey - II Supernova Survey. The redshifts of these SNe -
0.027 < z < 0.144 - cover a range hitherto sparsely sampled in the literature;
in particular, our SNe II-P sample contains nearly as many SNe in the Hubble
flow (z > 0.01) as all of the current literature on the SCM combined. We find
that the SDSS SNe have a very small intrinsic I-band dispersion (0.22 mag),
which can be attributed to selection effects. When the SCM is applied to the
combined SDSS-plus-literature set of SNe II-P, the dispersion increases to 0.29
mag, larger than the scatter for either set of SNe separately. We show that the
standardization cannot be further improved by eliminating SNe with positive
plateau decline rates, as proposed in Poznanski et al. (2009). We thoroughly
examine all potential systematic effects and conclude that for the SCM to be
useful for cosmology, the methods currently used to determine the Fe II
velocity at day 50 must be improved, and spectral templates able to encompass
the intrinsic variations of Type II-P SNe will be needed.Comment: Accepted for publication by ApJ; data used in this paper can be
downloaded from http://sdssdp47.fnal.gov/sdsssn/photometry/SNIIp.tgz;
citation errors correcte
Spatial and Temporal Recruitment Patterns of Juvenile Grunts (Haemulon spp.) in South Florida
Grunts (Haemulidae) are important fisheries species and represent a major component of reef fish communities in the Greater Caribbean region. To date, little is known about their recruitment pattems. Data from more than 2,000 visual fish counts from multiple natural and artificial reef studies in Broward County, Florida, over a seven-year period, were examined to identify both spatial and temporal trends in recruitment of juvenile (i.e., \u3c 5cm TL) grunts of the genus Haemulon. In general, data from these studies indicate that juvenile Haemulon spp. recruitment increases in the spring and peaks in the early summer months (i.e., June and July). Data from natural reef surveys revealed a predominantly nearshore preference for recruitment in water depths less than 8 m. However, on artificial reefs, recruitment commoniy occurred at 20 m depths. The biotic and abiotic factors determining the settlement of grunts are not clear and will be examined in future studies
Immunochip analysis identifies multiple susceptibility loci for systemic sclerosis
In this study, 1,833 systemic sclerosis (SSc) cases and 3,466 controls were genotyped with the Immunochip array. Classical alleles, amino acid residues, and SNPs across the human leukocyte antigen (HLA) region were imputed and tested. These analyses resulted in a model composed of six polymorphic amino acid positions and seven SNPs that explained the observed significant associations in the region. In addition, a replication step comprising 4,017 SSc cases and 5,935 controls was carried out for several selected non-HLA variants, reaching a total of 5,850 cases and 9,401 controls of European ancestry. Following this strategy, we identified and validated three SSc risk loci, including DNASE1L3 at 3p14, the SCHIP1-IL12A locus at 3q25, and ATG5 at 6q21, as well as a suggested association of the TREH-DDX6 locus at 11q23. The associations of several previously reported SSc risk loci were validated and further refined, and the observed peak of association in PXK was related to DNASE1L3. Our study has increased the number of known genetic associations with SSc, provided further insight into the pleiotropic effects of shared autoimmune risk factors, and highlighted the power of dense mapping for detecting previously overlooked susceptibility loci
Cortical-Bone Fragility - Insights from sFRP4 Deficiency in Pyle's Disease
BACKGROUND
Cortical-bone fragility is a common feature in osteoporosis that is linked to non
-
vertebral fractures. Regulation of cortical-bone homeostasis has proved elusive. The
study of genetic disorders of the skeleton can yield insights that fuel experimental
therapeutic approaches to the treatment of rare disorders and common skeletal
ailments.
METHODS
We evaluated four patients with Pyleâs disease, a genetic disorder that is characterized
by cortical-bone thinning, limb deformity, and fractures; two patients were examined
by means of exome sequencing, and two were examined by means of Sanger se
-
quencing. After a candidate gene was identified, we generated a knockout mouse
model that manifested the phenotype and studied the mechanisms responsible for
altered bone architecture.
RESULTS
In all affected patients, we found biallelic truncating mutations in
SFR P4
, the gene
encoding secreted frizzled-related protein 4, a soluble Wnt inhibitor. Mice deficient
in
Sfrp4
, like persons with Pyleâs disease, have increased amounts of trabecular bone
and unusually thin cortical bone, as a result of differential regulation of Wnt and
bone morphogenetic protein (BMP) signaling in these two bone compartments. Treat
-
ment of
Sfrp4-
deficient mice with a soluble Bmp2 receptor (RAP-661) or with anti
-
bodies to sclerostin corrected the cortical-bone defect.
CONCLUSIONS
Our study showed that Pyleâs disease was caused by a deficiency of sFRP4, that cortical-
bone and trabecular-bone homeostasis were governed by different mechanisms, and
that sFRP4-mediated cross-regulation between Wnt and BMP signaling was critical
for achieving proper cortical-bone thickness and stability. (Funded by the Swiss Na
-
tional Foundation and the National Institutes of Health.
- âŠ