The Liability Threshold Model for Censored Twin Data

Family studies provide an important tool for understanding etiology of diseases, with the key aim of discovering evidence of family aggregation and to determine if such aggregation can be attributed to genetic components. Heritability and concordance estimates are routinely calculated in twin studies of diseases, as a way of quantifying such genetic contribution. The endpoint in these studies are typically defined as occurrence of a disease versus death without the disease. However, a large fraction of the subjects may still be alive at the time of follow-up without having experienced the disease thus still being at risk. Ignoring this right-censoring can lead to severely biased estimates. We propose to extend the classical liability threshold model with inverse probability of censoring weighting of complete observations. This leads to a flexible way of modeling twin concordance and obtaining consistent estimates of heritability. We apply the method in simulations and to data from the population based Danish twin cohort where we describe the dependence in prostate cancer occurrence in twins

Optimal Harvest Time of Florida Valencia Oranges to Maximize Grower Returns

Research goals are to estimate the optimal harvest time of Florida Valencia oranges for Florida growers and calculate the economic consequences of harvesting inside or outside the optimal window. Determining the optimal fruit harvest time will help the industry anticipate how mechanical harvesting may affect deviations from this optimum.Crop Production/Industries,

Malawi’s Maize Marketing System

National food security in Malawi depends on improving the performance of maize markets. Ensuring that grain is consistently available at tolerable prices is crucial for consumers’ food security. At the same time, surplus producing farmers need to receive farm-gate prices consistently above production costs to intensify the use of fertilizer and other productivity enhancing technologies in a sustainable manner. These concerns give rise to the classic food price dilemma for policy makers in Malawi: how to keep prices low enough to ensure low income consumers’ access to food while keeping prices high enough to promote farm production incentives. These tensions cannot be avoided but they can be relieved through reducing food marketing margins, which shrink the wedge between producer and consumer prices. Moreover, Malawi faces major political and economic problems associated with food price instability especially given its dependence on rain fed agriculture in a region prone to drought. These issues show that improving the performance of maize markets is at the core of achieving sustainable food security and poverty reduction in Malawi.food security, Malawi, maize, marketing, food policy, Agricultural and Food Policy, Community/Rural/Urban Development, Food Security and Poverty, International Development, Marketing, q12, q18,

How much H and He is "hidden" in SNe Ib/c? -- II. Intermediate-mass objects: a 22 M⊙_{\odot} progenitor case study

Stripped envelope supernovae are a sub-class of core collapse supernovae showing several stages of H/He shell stripping that determines the class: H-free/He-poor SNe are classified as Type Ic, H-poor/He-rich are Type Ib, and H/He-rich are Type IIb. Stripping H/He with only stellar wind requires significantly higher mass loss rates than observed while binary-involved mass transfer may usually not strip enough to produce H/He free SNe. Type Ib/c SNe are sometimes found to include weak H/He transient lines as a product of a trace amount of H/He left over from stripping processes. The extent and mass of the H/He required to produce these lines is not well known. In this work, a 22 M$_{\odot}$ progenitor model is stripped of the H/He shells in five steps prior to collapse and then exploded at four explosion energies. Requiring both optical and NIR He I lines for helium identification does not allow much He mass to be hidden in SE--SNE. Increasing the mass of He above the CO core delays the visibility of O I 7774 in early spectra. Our SN Ib-like models are capable of reproducing the spectral evolution of a set of observed SNe with reasonable estimated $E_\mathrm{k}$ accuracy. Our SN\,IIb-like models can partially reproduce low energy observed SN IIb, but we find no observed comparison for the SN IIb-like models with high $E_\mathrm{k}$.Comment: 19 pages, 15 figures. Accepted by MNRAS, awaiting publicatio

Growth, Condition, and Trophic Relations of Stocked Trout in Southern Appalachian Mountain Streams

Stream trout fisheries are among the most popular and valuable in the United States, but many are dependent on hatcheries to sustain fishing and harvest. Thus, understanding the ecology of hatchery‐reared trout stocked in natural environments is fundamental to management. We evaluated the growth, condition, and trophic relations of Brook Trout Salvelinus fontinalis, Brown Trout Salmo trutta, and Rainbow Trout Oncorhynchus mykiss that were stocked in southern Appalachian Mountain streams in western North Carolina. Stocked and wild (naturalized) trout were sampled over time (monthly; September 2012–June 2013) to compare condition and diet composition and to evaluate temporal dynamics of trophic position with stable isotope analysis. Relative weights (Wr) of stocked trout were inversely associated with their stream residence time but were consistently higher than those of wild trout. Weight loss of harvested stocked trout was similar among species and sizes, but fish stocked earlier lost more weight. Overall, 40% of 141 stomachs from stocked trout were empty compared to 15% of wild trout stomachs (N = 26). We identified a much higher rate of piscivory in wild trout (18 times that of stocked trout), and wild trout were 4.3 times more likely to consume gastropods relative to stocked trout. Hatchery‐reared trout were isotopically similar to co‐occurring wild fish for both δ13C and δ15N values but were less variable than wild trout. Differences in sulfur isotope ratios (δ34S) between wild and hatchery‐reared trout indicated that the diets of wild fish were enriched in δ34S relative to the diets of hatchery‐reared fish. Although hatcheryreared trout consumed prey items similar to those of wild fish, differences in consumption or behavior (e.g., reduced feeding) may have resulted in lower condition and negative growth. These findings provide critical insight on the trophic dynamics of stocked trout and may assist in developing and enhancing stream trout fisheries

Genome sequence of an alphaherpesvirus from a beluga whale (Delphinapterus leucas)

Beluga whale alphaherpesvirus 1 was isolated from a blowhole swab taken from a juvenile beluga whale. The genome is 144,144 bp in size and contains 86 putative genes. The virus groups phylogenetically with members of the genus Varicellovirus in subfamily Alphaherpesvirinae and is the first alphaherpesvirus sequenced from a marine mammal

Variations of Steroid Hormone Metabolites in Serum and Urine in Polycystic Ovary Syndrome after Nafarelin Stimulation: Evidence for an Altered Corticoid Excretion.

To evaluate the clinical relevance of testing pituitary-ovarian responses in patients suffering from polycystic ovary syndrome (PCOS) with the GnRH agonist nafarelin, a 1.2-mg dose of nafarelin was given intranasally to 19 women with PCOS and 15 healthy premenopausal women. The subsequent analysis of steroids in both serum and urine during the test was carried out at several time points for up to 24 h. Serum levels of 17 alpha-hydroxyprogesterone were elevated at all time points of the test in PCOS patients vs. controls [at baseline, 3.5 +/- 0.2 vs. 1.8 +/- 0.1 nmol/L (P < 0.001); at 24 h, 9.9 +/- 0.9 vs. 4.9 +/- 0.3 nmol/L (P < 0.001)]. Basal levels of androstenedione were higher in the patient group, but there was no significant change during the test in either group. Serum testosterone levels were also found to differ in PCOS patients compared with the control values at baseline (2.2 +/- 0.2 vs. 1.5 +/- 0.1 nmol/L; P < 0.05) and after nafarelin treatment (at 24 h, 3.2 +/- 0.4 vs. 1.8 +/- 0.2 nmol/L; P < 0.05). Serum estradiol levels rose significantly in both groups during the test; the posttest levels were significantly higher in PCOS than in controls. The PCOS patients displayed a significant increase in androgen and gestagen metabolites as well as in glucocorticoid metabolites excreted in the urine during the 24 h. In the control subjects, except for 17 alpha-hydroxypregnanolone, which rose significantly, none of the urinary steroids investigated showed relevant changes during the nafarelin test. The posttest excretion of allo-tetrahydrocortisol (1.4 +/- 0.2 vs. 0.3 +/- 0.1 mumol/g creatinine; P < 0.001) and the increase in 17 alpha-hydroxypregnanolone excretion (1.4 +/- 0.2 vs. 0.3 +/- 0.1 mumol/g creatinine; P < 0.001) were distinctly higher in PCOS patients than in the controls; the diagnostic sensitivity of the combination of both parameters was 89% at a 93% specificity. Thus, measurements of 17 alpha-hydroxyprogesterone levels in serum and of urinary allo-tetrahydrocortisol and 17 alpha-hydroxypregnanolone after nafarelin treatment make this stimulation test a valuable diagnostic tool for identifying PCOS patients. The significant changes in the excretion of urinary androgen and gestagen metabolites, unmasked by GnRH agonist stimulation, suggest a functional alteration of the pituitary-ovarian axis. The reason for the increased excretion of glucocorticoid metabolites after nafarelin stimulation remains to be clarified

Thomas H. Riley Jr. Correspondence

Entries include brief biographical information, a lengthy typed biography on Brunswick Savings Institution, Inc., Brunswick, Maine, stationery, and a letter of receipt for several copies of the booklet Mutual Savings Banks

Identifying Advantages and Disadvantages of Variable Rate Irrigation – An Updated Review

Variable rate irrigation (VRI) sprinklers on mechanical move irrigation systems (center pivot or lateral move) have been commercially available since 2004. Although the number of VRI, zone or individual sprinkler, systems adopted to date is lower than expected there is a continued interest to harness this technology, especially when climate variability, regulatory nutrient management, water conservation policies, and declining water for agriculture compound the challenges involved for irrigated crop production. This article reviews the potential advantages and potential disadvantages of VRI technology for moving sprinklers, provides updated examples on such aspects, suggests a protocol for designing and implementing VRI technology and reports on the recent advancements. The advantages of VRI technology are demonstrated in the areas of agronomic improvement, greater economic returns, environmental protection and risk management, while the main drawbacks to VRI technology include the complexity to successfully implement the technology and the lack of evidence that it assures better performance in net profit or water savings. Although advances have been made in VRI technologies, its penetration into the market will continue to depend on tangible and perceived benefits by producers