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Estimating egg mass-body mass relationships in birds
Abstract
The mass of a bird’s egg is a critical attribute of the species’ life history and represents a fundamental component of reproductive effort. Indeed, the tradeoff between the number of eggs in a clutch and clutch mass lies at the heart of understanding how environmental attributes such as nest predation or adult mortality influence reproductive investment. However, egg masses have not been reported for the majority of avian species. We capitalized on the strong allometric relationship between avian body mass and egg mass to produce egg mass estimates for over 5,500 species previously lacking such information. These estimates are accompanied by measures of the robustness of the regressions used to produce them (e.g., sample size, root mean square error [RMSE] of estimation, coefficient of determination, and degree of extrapolation), thus allowing independent evaluation of the suitability of any estimate to address a particular research question relating to avian life history. Most estimates (~5,000) were based on family-level egg mass–body mass regressions, with the remainder derived from other relationships such as ordinal regressions. We compared estimating regressions based on adult vs. female body masses and, after finding little difference between the 2, based our final estimates on adult masses as those were more numerous in the literature. What small differences between adult- and female-based regressions that did occur were not related to sexual size dimorphism across families. These new estimates, coupled with ~5,000 egg masses reported in the literature, provide a foundation of over 10,000 species for wider investigations assessing variation in reproductive effort in birds over a broad array of ecological and evolutionary contexts
Properties of Sequential Chromospheric Brightenings and Associated Flare Ribbons
We report on the physical properties of solar sequential chromospheric
brightenings (SCBs) observed in conjunction with moderate-sized chromospheric
flares with associated CMEs. To characterize these ephemeral events, we
developed automated procedures to identify and track subsections (kernels) of
solar flares and associated SCBs using high resolution H-alpha images.
Following the algorithmic identification and a statistical analysis, we compare
and find the following: SCBs are distinctly different from flare kernels in
their temporal characteristics of intensity, Doppler structure, duration, and
location properties. We demonstrate that flare ribbons are themselves made up
of subsections exhibiting differing characteristics. Flare kernels are measured
to have a mean propagation speed of 0.2 km/s and a maximum speed of 2.3 km/s
over a mean distance of 5 x 10^3 km. Within the studied population of SCBs,
different classes of characteristics are observed with coincident negative,
positive, or both negative and positive Doppler shifts of a few km/s. The
appearance of SCBs precede peak flare intensity by ~12 minutes and decay ~1
hour later. They are also found to propagate laterally away from flare center
in clusters at 41 km/s or 89 km/s. Given SCBs distinctive nature compared to
flares, we suggest a different physical mechanism relating to their origin than
the associated flare. We present a heuristic model of the origin of SCBs.Comment: 24 pages, 17 figure
Outcome of emergency cerclage for advanced cervical dilatation: a retrospective analysis
Background: The objective was to evaluate the outcome of late second trimester emergency cerclage in patients with advanced cervical dilatation with bulging membranes.Methods: Setting: department of obstetrics and gynaecology, PSG Institute of medical sciences & research, Coimbatore, Tamil Nadu, India. This is a retrospective study of case files of patients who underwent emergency late second trimester cerclage for advanced cervical dilatation with bulging membranes between January 2009 to January 2014. McDonald’s technique was used in all the cases.Results:Altogether, 7 patients (100%) underwent late second trimester emergency cerclage between 20-28 weeks of gestational age, out of which three patients (42.86%) had term deliveries (>37w), and 3 patients (42.86 %) carried on their pregnancies to more than 32 weeks resulting in healthy live born babies. Two of them delivered by normal vaginal delivery, 4 underwent LSCS, and one patient had severe abdominal pain with bleeding and draining per vaginum after 3 days of cerclage, in view of which the stitch was removed. Subsequently, the patient expelled a live foetus weighing 620gms, which died in the Neonatal Intensive Care Unit (NICU) after 3 hours. This procedure prolonged the duration of pregnancy in all patients with a mean duration of 70.4 days. The mean gestational age at the time of delivery was 34.33 weeks. The mean birth weight was 2.18 kg and ranged between 1.97 to 2.64 kg. The mean APGAR at one minute was 8/10 and the mean duration of stay in NICU was 1.66 days. All the new-born babies were healthy at the time of discharge. The live birth rate following emergency late second trimester cerclage in this series was 85.75%.  Conclusion:Favourable neonatal outcome can be accomplished in patients with cervical incompetence in the second trimester of pregnancy following emergency cervical suturing, even if performed when the membranes are bulging through the cervix.
CONGENITAL ATLANTO-AXIAL DISLOCATION
Atlanto-axial dislocation IS an uncommon condition. It is usually secondary to trauma, infection (tuberculous and non-tuberculous atlas and axis) and rheumatoid arthritis. Othe
Extent of Awareness of Distance Learners of Tamil Nadu Agricultural University
The present research was framed to assess the awareness level of distance learners of Tamil Nadu Agricultural University. Three certificate courses were selected based on maximum number of enrollment, viz, Gardening & landscaping, Mushroom production & Solid waste management and vermicomposting. Ex-post facto research design was employed. A total of 150 respondents were selected from the three courses by equal allocation method proportionate random sampling. A well-structured questionnaire was prepared and the information was collected by sending questionnaires through post. The 108 individuals who responded were taken as the sample for the study. The results of the research pointed out that nearly three- fourths of the respondents possessed medium level of awareness on selected technologies
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