Uniform irrigation with a low-head bubbler system

Existing closed-conduit irrigation systems are capable of saving water by increasing application uniformity. But, because most of them require pumping to pressurize water for distribution, the water is saved often at the expense of increased energy consumption. This paper describes a new irrigation system that reduces the energy requirement by using inexpensive, thin-walled, corrugated plastic pipe of sufficient diameter that the pressure head often available from a surface ditch is sufficient. A simple installation technique, giving extremely high application uniformity, is described for the system for permanent crops. Costs for the system can be less than for comparable sprinkler or drip irrigation systems.     

The effects of DDT upon flat and vesicular bilayers studied by a fluorescent probe

The effect of DDT and several analogs upon bilayer membranes was studied, using the fluorescent dye di (octadecyl)oxycarbocyanin as a probe. It was shown in flat bilayers of Torpedo electroplax phospholipids, using fluorescence correlation spectroscopy, that neither DDT nor its physiologically inactive analog, p,p′-hydroxy-DDT, affected the fluidity of the membrane. However DDT, and not the analog, displaced half of the dye from the membrane. In studies with lecithin or Torpedo electroplax phospholipid vesicles, using simple fluorescence measurements, no displacement of the dye was observed by DDT or its analogs.     

Studies of Partial Amino Acid Sequences of γ‐40k Secalins of Rye

Though γ‐40k secalins are a major protein type within rye storage proteins, total amino acid sequences are not as well known as the gluten proteins of wheat. Well‐reputed structural features such as amino acid compositions and molecular masses indicated a close relationship between γ‐40k secalins and γ‐gliadins of wheat, but the degree of homology of amino acid sequences and the positions of intramolecular disulfide bonds are unknown. Therefore, two major components of γ‐40k secalins (R1, R2) were analyzed for partial amino acid sequences. The R1 and R2, derivatized with 4‐vinylpyridine, were isolated from the prolamin fraction of rye cultivar Danko by means of a two‐step RP‐HPLC on C₁₈ silica gel. The proteins were digested in parallel with trypsin and thermolysin, and the partial hydrolyzates were separated by RP‐HPLC. Simultaneous measurement of UV absorbance at 210 and 254 nm allowed the detection of all peptides eluted as well as the specific detection of pyridylethylated cysteine peptides. Isolated peptides were characterized by sequence analysis, and in parts by mass spectrometry, and assigned to known sequences of γ‐gliadins. The results demonstrated that the N‐terminal domain of R1 and R2 remained undigested after tryptic hydrolysis; they were in agreement with the N‐terminal domain of γ‐gliadins in their molecular masses and in the absence of cysteine residues. Most of the isolated peptides originated from the C‐terminal domains, they covered 83% (R1) and 77% (R2), respectively, of the C‐terminal domain of a known γ‐gliadin (clone pW1020). Comparison of R1 and R2 revealed differences only in a few sequence positions. The degree of homology between the C‐terminal domains present in γ‐40k secalins and γ‐gliadins was ≈85%. All eight cysteine residues of γ‐gliadins were found in R1 and R2 sequences. Remarkably, sequences close to corresponding cysteine residues were identical for γ‐40k secalins and γ‐gliadins. Therefore, it can be assumed that the positions of intramolecular disulfide links are homologous.     

Single Kernel Near‐Infrared Analysis of Tetraploid (Durum) Wheat for Classification of the Waxy Condition

Plant breeding programs are active worldwide in the development of waxy hexaploid (Triticum aestivum L.) and tetraploid (T. turgidum L. var. durum) wheats. Conventional breeding practices will produce waxy cultivars adapted to their intended geographical region that confer unique end use characteristics. Essential to waxy wheat development, a means to rapidly and, ideally, nondestructively identify the waxy condition is needed for point‐of‐sale use. The study described herein evaluated the effectiveness of near‐infrared (NIR) reflectance single‐kernel spectroscopy for classification of durum wheat into its four possible waxy alleles: wild type, waxy, and the two intermediate states in which a null allele occurs at either of the two homologous genes (Wx‐1A and Wx‐1B) that encodes for the production of the enzyme granule bound starch synthase (GBSS) that controls amylose synthesis. Two years of breeders' samples (2003 and 2004), corresponding to 47 unique lines subdivided about equally into the four GBSS genotypes, were scanned in reflectance (1,000–1,700 nm) on an individual kernel basis. Linear discriminant analysis models were developed using the best set of four wavelengths, best four wavelength differences, and best four principal components. Each model consistently demonstrated the high ability (typically >95% of the time) to classify the fully waxy genotype. However, correct classification among the three other genotypes (wild type, wx‐A1 null, and wx‐B1 null) was generally not possible.     

The effect of prednisone on histologic and gross characteristics in canine mast cell tumors

The objective of the study was to determine whether neoadjuvant prednisone therapy affects histological features of cutaneous and subcutaneous mast cell tumors. Twenty-eight dogs with a treatment naïve > 1-cm diameter mast cell tumor (MCT) were randomly assigned (Random number generator; Random.org, Dublin, Ireland) in a blinded fashion to receive either prednisone or placebo (Quality Food Center Pharmacy, Kirkland, Washington, USA). Volumes of mast cell tumors were calculated before incisional and excisional biopsies. Following incisional biopsy, patients received either prednisone (1 mg/kg body weight) daily or a placebo for 7 to 14 days leading up to excisional biopsy. Tumor grade for cutaneous MCT, and mitotic count and atypia for all tumors were reported. Perioperative treatment with prednisone had no significant effect on tumor grade, atypia, or mitotic count. Tumor volume was significantly decreased with prednisone treatment. The use of neoadjuvant prednisone to decrease MCT volume in order to facilitate tumor excision, can be considered without significant concern for change of tumor histologic features in the common population of low- to intermediate-grade MCT.     

Maturation and related aspects in clonal forestry—Part I: concepts,regulation and consequences of phase change

Progression from the juvenile to mature phase in woody plants is accompanied by changes in characteristics as diverse as adventitious rooting capacity, leaf morphology, canopy architecture, wood anatomy and reproductive development. Many concepts of phase change, the intensity and duration of changes that occur during the phase transition, and the practical consequences of plant maturation for growth and development, are poorly understood. Little is known about the physiological and environmental control of maturation in woody plants compared with herbaceous plants, and reliable markers of phase state have only been developed for a few species, mainly conifers. Understanding the mechanisms and forms of phase change is a prerequisite for achieving maturation or rejuvenation for applications such as seed production or clonal propagation. This review describes concepts, terminology and consequences of phase change, combining theoretical and practical aspects of tree maturation that relate to clonal forestry.