115 Nitrogen fertilizer effects on above ground sward characteristics and beef heifer performance from native warm-season grass blends

A 2-yr study was conducted at Black Belt Research and Extension Center in Marion Junction, AL, to evaluate the effect of nitrogen (N) fertilizer application rate on forage production characteristics, nutritive value, and animal performance of beef heifers grazing a mixture of native warm-season grasses (NWSG) including big bluestem, little bluestem, and indiangrass. Six, two-hectare plots were randomly assigned to one of two treatments (0 or 67 kg N ha-1 applied in early April; n = 3 replications per treatment). Paddocks were continuously stocked with four weaned Angus × Simmental beef heifers (initial BW 288 ± 7 kg) from late May/early June through mid-to-late August during 2018 (73 grazing d) and 2019 (70 grazing d), respectively. Put-and-take cattle were used to manage forage to a target of 38 cm. Forage mass and canopy heights were collected every two weeks during the trial. Visual ground cover ratings, canopy light interception, and botanical composition were measured at the beginning and end of the trial in each year. Hand-plucked samples were collected every two weeks during the grazing trial to determine forage nutritional value. Data were analyzed using the PROC MIXED procedure in SAS 9.4, and differences were declared significant when P ≤ 0.05. Nitrogen fertilized NWSG had greater crude protein (P < 0.0001), sward heights (P = 0.0003), and canopy light interception at the beginning of the season (P = 0.0049) compared to non-fertilized paddocks. However, there were no differences (P ≥ 0.05) among N-fertility treatments for mean forage mass, heifer ADG, or BCS across the 2-yr study. Botanical composition data indicated that indiangrass decreased from 64% to 61% (P = 0.0022) and weed pressure increased from 11% to 15% (P = 0.0064) across the summer grazing season. Canopy light interception decreased by 51% from early June to August in fertilized NWSG and 26% in unfertilized paddocks, respectively. These data illustrate that NWSG systems may provide a viable grazing system in the summer months under reduced N inputs.

Binding of inositol phosphate to DNA-PK and stimulation of double-strand break repair

In mammalian cells, double-strand breaks in DNA can be repaired by nonhomologous end-joining (NHEJ), a process dependent upon Ku70/80, DNA-PKcs, XRCC4, and DNA ligase IV. Starting with HeLa cell-free extracts, which promote NHEJ in a reaction dependent upon all of these proteins, we have purified a novel factor that stimulates DNA end-joining in vitro. Using a combination of phosphorus NMR, mass spectroscopy, and strong anion exchange chromatography, we identify this factor as inositol hexakisphosphate (IP6). Purified IP6 is bound by DNA-PK and specifically stimulates DNA-PK-dependent end-joining in vitro. The involvement of inositol phosphate in DNA-PK-dependent NHEJ is of particular interest since the catalytic domain of DNA-PKcs is similar to that found in the phosphatidylinositol 3 (PI 3)-kinase family.

Risk factors for development of first symptomatic Giardia infection among infants of a birth cohort in rural Egypt

Giardia infection is associated with diarrheal diseases among infants and young children in both industrialized and developing countries. A study was conducted to demonstrate the predisposing factors for occurrence of the first symptomatic Giardia infection among infants in rural Egypt. The study cohort was followed from birth through the first year of life. Univariate and multivariate analyses of data revealed that infants less than six months of age were at special risk for developing their first symptomatic infection compared with infants more than six months of age. Analysis of the data, furthermore, revealed an increased risk of infant Giardia infection associated with living in a household without a latrine (relative risk [RR] = 2.63, confidence interval [CI] = 1.4-4.9, P < 0.05), a mud floor in the sleeping rooms (RR = 1.79, CI = 1.O30-3.0, P < 0.05), and household exposure to more than 10 chickens (RR = 2.5, CI = 1.13-5.56, P < 0.05). In contrast, the mother's education beyond the primary level (RR = 0.28, CI = 0.09-0.85, P < 0.05), drinking water stored in metallic containers (RR = 0.33, CI = 0.11-0.98, P < 0.05), and male sex (RR = 0.52, CI = 0.3-0.89, P < 0.05) were associated with decreased risk of Giardia infection. These data suggest that in addition to age of infants, poverty, low education, gender discrimination, and certain environmental conditions potentiated the risk for developing the first symptomatic infection.

An approach to the management of children with cleft lip or palate

A number of the more common problems which may be encountered in the management of children born with cleft lip and/or cleft palate is discussed. Present-day concepts of aetiology, parental counselling and timing of surgery are referred to and contentious aspects of management are mentioned.