<p>Prinos zrna predstavlja jednu od najznačajnijih i najsloženijih osobina u oplemenjivanju biljaka. Poznavanje razvića, rastenja i akumulacije suve materije, omogućava pravilan odabir genotipova i odgovarajuće tehnologije gajenja. Cilj istraživanja je bio da se izvr&scaron;i ispitivanje filohrona, akumulacije i translokacije suve materije nadzemnog dela biljaka, prinosa zrna i komponenti prinosa, različitih genotipova ozime p&scaron;enice i ječma sejanih u vi&scaron;e rokova setve i vegetacionih sezona. Zatim da se utvrdi odgovarajuća jednačina koja opisuje akumulaciju suve materije i pojavu listova na glavnom stablu ječma i p&scaron;enice u funkciji sume temperatura tokom različitih rokova setve i vegetacionih sezona. U ogled je bilo uključeno po &scaron;est genotipova ozimog dvoredog ječma i ozime p&scaron;enice različitog porekla, pedigrea i agronomskih osobina, sejanih dve sezone u četiri roka setve. Sredinom cvetanja i u punoj zrelosti, uzeto je 10 slučajno odabranih biljaka. Na uzetim biljkama određena je masa pojedinačnih organa i komponente prinosa, kao i translokacija suve materije i doprinos asimilata akumuliranih pre cvetanja u masi zrna. Za utvrđivanje filohrona i ukupnog broja listova, dva puta nedeljno se očitavao broj listova na obeleženim biljkama tokom čitave sezone. Istovremeno se uzimao i uzorak od pet biljaka u cilju praćenja akumulacije suve materije. Sezona, rok setve i sorta su imali značajan uticaj na variranje ukupnog broja listova i filohrona kod ječma i p&scaron;enice. U proseku, sorte ječma su formirale vi&scaron;e listova u odnosu na p&scaron;enicu, dok se p&scaron;enica karakteri&scaron;e dužim filohronom. Kasnija setva dovela je do značajnog smanjenja broja listova i skraćenja filohrona kod obe vrste. U zavisnosti od sezone, roka setve, sorte i njihove interakcije menjala se i biomasa biljaka u cvetanju i prinos zrna. Translokacija suve materije je bila u pozitivnoj korelaciji sa biomasom biljaka u cvetanju. Akumulacija biomase nadzemnog dela biljaka tokom sezone, pratila je tipičan sigmoidni obrazac u svim kombinacijama rokova setve i sorti. Od tri posmatrane nelinearne jednačine, Logistička jednačina se pokazala najprikladnijom za opisivanje akumulacije suve<br />materije tokom sezone kod ječma i p&scaron;enice. Rezultati istraživanja ukazuju na značaj vegetativne mase biljaka u cvetanju, koja predstavlja bitan izvor asimilata za translokaciju u zrno. Ovi rezultati ukazuju da je tokom oplemenjivanja strnih žita, neophodno stvarati genotipove sa većim brojem listova koji bolje nakupljaju biomasu, odnosno genotipove koji će u optimalnom roku setve, imati usklađen fenolo&scaron;ki razvoj sa agroekolo&scaron;kim uslovima u području Panonske nizije.</p> / <p>Grain yield is one of the most important and complex traits in plant breeding. Knowledge about crop development, growth and dry matter accumulation enables the appropriate selection of genotypes and field technology. The aims of this study were to investigate the variability of phyllochron, dry matter accumulation and translocation, grain yield and yield components of various wheat and barley genotypes, in relation to the sowing date and growing season. Furthermore, the goal was to find the equation that would appropriately describe dry matter accumulation and leaf appearance of wheat and barley. Six winter barley and six winter wheat genotypes, characterized by different origin, pedigree and agronomic traits, were sown in two growing seasons across four sowing dates. At the anthesis and physiological maturity, 10 randomly selected plants were manually cut at ground level. Dry mass of different plant organs, yield components, dry matter translocation and contribution of pre-heading dry matter to grain yield were determined. To determine the leaf number and phyllochron, measuring was done according to the Haun scale on three tagged plants per replication three times per week. Also, samples consisting of five plants were collected to determine dry matter accumulation. Growing season, sowing date and variety had significant influence on the final leaf number and phyllochron of wheat and barley. At average, barley varieties had more leaf compared to wheat, while wheat had higher phyllochron values. Late sowing reduced the final leaf number and phyllochron in both barley and wheat. Furthermore, growing season, sowing date, variety and sowing date &times; variety interaction had significant influence on crop biomass at anthesis and grain yield. Dry matter translocation was in positive correlation with dry matter content at anthesis. Dry matter accumulation across growing seasons had a typical sigmoid pattern in every combination of sowing date and variety. Among studied models, the logistic equation was the most appropriate for description of dry matter accumulation in wheat and barley. Results from this study highlight the importance of dry matter content at anthesis, which represent a significant source of assimilates for translocation into the grain. These results indicated that during the selection of small grain cereals, it is necessary to develop genotypes characterized by higher leaf number and increased biomass, i.e. genotypes that in optimal sowing dates, have an adjusted phenological development to the agro-ecological conditions of the Panonian plane.</p>

Abstract available in the Pharmacotherapy: The Journal of Human Pharmacology and Drug Therapy.

No description available.

Objectives The objectives of this study included developing and validating a stability-indicating high-performance liquid chromatographic (HPLC) method with ultraviolet (UV) detection for the determination of buprenorphine in a buccal solution for veterinary use, and applying that method to determine the stability of a 3 mg/ml buprenorphine preparation in room temperature and refrigerated storage conditions. This preparation, intended for buccal administration in feline patients, plays an important role in pain management in cats. Methods A stability-indicating HPLC method was developed and validated for system suitability, accuracy, repeatability, intermediate precision, specificity, linearity and robustness based on US Pharmacopeia (USP) General Chapter. The method was then applied to the study of potency changes over 90 days in a buccal buprenorphine solution stored at two temperatures. Results All HPLC-UV method data met acceptable criteria for the quantification of buprenorphine in a buccal solution formulation. The buprenorphine concentrations found in each stability sample remained within the 90–110% of label claim throughout the 90 days of study. All stability test bottles of the buprenorphine buccal solution retained their original appearance. For the room temperature bottles, some white particulate matter was noted in the threads of the container bottles starting at day 21. The pH of the preparations during the course of the study was in the range of 3.57–4.06 and 4.01–4.16 for the room temperature and refrigerated samples, respectively. Conclusions and Relevance Pharmacists have compounded a concentrated 3 mg/ml buccal solution to use easily in the home care or outpatient setting for treatment of feline pain. Prior to this investigation, pharmacists empirically assigned beyond-use dates to this formulation based on standards in USP General ChapterPharmaceutical Compounding – Nonsterile Preparations. This study of a 3 mg/ml buprenorphine buccal solution indicates stability through 90 days.

Background:Compounded vitamin K oral liquids may be useful in some patient populations, or when an appropriate solid dosage form is not available. While vitamin K oral liquid is typically prepared with sterile water for injection (SWFI), other compounding agents may be more palatable.Objective:To evaluate stability of compounded vitamin K liquids in SWFI, Ora-Sweet, simple syrup, cherry syrup, and SyrPalta stored in amber plastic oral syringes.Methods:Five types of compounded vitamin K liquids were prepared in triplicate—Ora-Sweet, simple syrup, cherry syrup, SyrPalta, and SWFI without flavoring; aliquoted into amber plastic oral syringes; and stored in a laboratory refrigerator (4.9°C to 5.4°C). On study days, 3 syringes from each batch were removed, diluted to assay concentration, and compared with a freshly prepared US Pharmacopeia reference solution. The samples and reference were analyzed using a previously validated high-performance liquid chromatography–ultraviolet method. Product stability was defined as 90% to 110% labeled amount. Results were further compared using a 2-way ANOVA (analysis of variance; P = .05) with post hoc Tukey’s correction for multiple comparisons.Results:Vitamin K in SWFI, SyrPalta, and cherry syrup was stable for 21 days, 7 days, and 24 hours, respectively, under refrigeration in amber plastic oral syringes. Vitamin K in Ora-Sweet and simple syrup demonstrated high within-day variability and low potency. Statistically significant differences were detected between the SWFI formulation and all other vehicles.Conclusion:Vitamin K in SWFI is appropriate for longer-term storage of unit-dosed vitamin K; however, SyrPalta and cherry syrup may be used for short-term storage or immediate administration of vitamin K.

Purpose:The stability of sildenafil in combination with heparin and dopamine was evaluated. Methods:A stability-indicating high-performance liquid chromatography method with ultraviolet detection was developed for sildenafil citrate and validated. The method was applied to the investigation of sildenafil alone, sildenafil with heparin, sildenafil with dopamine, and sildenafil with heparin and with dopamine, all in 5% dextrose injection at room temperature and under refrigeration for 30 days. Samples of 100 μL were pulled from each storage bottle on each sampling day, diluted in mobile phase, and assayed in duplicate. Samples were tested on days 0, 1, 2, 3, 4, 5, 7, 9, 12, 14, 21, and 30. Each preparation was visually inspected for precipitation and color change. The percent recovery in each study sample was determined by comparing the peak area of sildenafil in the sample with the peak area of sildenafil from a freshly prepared 100-μg/mL standard in mobile phase. Results:The sildenafil alone, sildenafil with heparin, and sildenafil with dopamine remained within 90–110% of the expected sildenafil potency for at least 30 days at both temperatures. The preparation of sildenafil with both heparin and dopamine fell below 90% potency after 3 days at room temperature and 21 days in the refrigerator. Conclusion:Sildenafil prepared in 5% dextrose injection alone, with heparin, and with dopamine retained over 90% potency after 30 days of storage at room temperature and under refrigeration. Sildenafil prepared with both heparin and dopamine had a potency of

No description available.

Motivated by the Guaranteed Minimum Death Benefits (GMDB) in variable annuities, we are interested in valuing equity-linked options whose expiry date is the time of the death of the policyholder. Because the time-until-death distribution can be approximated by linear combinations of exponential distributions or mixtures of Erlang distributions, the analysis can be reduced to the case where the time-until-death distribution is exponential or Erlang. We present two probability methods to price American options with an exponential expiry date. Both methods give the same results. An American option with Erlang expiry date can be seen as an extension of the exponential expiry date case. We calculate its price as the sum of the price of the corresponding European option and the early exercise premium. Because the optimal exercise boundary takes the form of a staircase, the pricing formula is a triple sum. We determine the optimal exercise boundary recursively by imposing the “smooth pasting” condition. The examples of the put option, the exchange option, and the maximum option are provided to illustrate how the methods work. Another issue related to variable annuities is the surrender behavior of the policyholders. To model this behavior, we suggest using barrier options. We generalize the reflection principle and use it to derive explicit formulas for outside barrier options, double barrier options with constant barriers, and double barrier options with time varying exponential barriers. Finally, we provide a method to approximate the distribution of the time-until-death random variable by combinations of exponential distributions or mixtures of Erlang distributions. Compared to directly fitting the distributions, my method has two advantages: 1) It is more robust to the initial guess. 2) It is more likely to obtain the global minimizer.

To improve management and control of jointed goatgrass (Aegilops cylindrica Host.) on traditional winter wheat (Triticum aestivum L.) cropland, a better understanding of the effects spring crop and wheat planting date have on weed populations and wheat yield is needed. A study of the effects of safflower (a spring crop) and wheat planting dates (early vs late) was conducted over a 2-yr period. Long term effects will be examined over a 5-yr period. The effects these treatments had on yield, weed seed contamination, jointed goatgrass population density, and soil seedbank concentration were measured. Two identical experiments were initiated, the first beginning in 1996, the second in 1997. In experiment one, initial plant counts showed similar numbers of jointed goatgrass plants in all treatments. In experiment two, initial spring plant counts showed increased numbers of jointed goatgrass in unplanted plots prior to planting safflower, and slightly reduced population densities in October-planted wheat when compared to September-planted wheat. Winter wheat yields were 25% and 35% higher in September-planted wheat than in October-planted wheat, in 1997 in experiment one, and1998 in experiment two, respectively. Crop contamination with jointed goatgrass propagules was four times higher in early vs late-planted wheat in 1997, and 36% higher in 1998. Jointed goatgrass plants in safflower were reduced 97% compared to preplan! counts in both experiments. In experiment one, 1998 fallow season plant counts showed 55% and 75% less jointed goatgrass in fallow safflower plots than in fallow plots of September- and October-planted wheat, respectively, with fallow plots of September-planted wheat having 46% less than fallow plots of October-planted wheat. Soil seed bank concentrations were highest at the 0-5 cm depth of October-planted wheat, which had nearly a 10-fold higher concentrations compared to safflower and September-planted wheat at this depth. There were no differences at depths below 5cm. This study showed the use of safflower to be a very useful management tool for reducing jointed goatgrass populations. September-planted wheat, with similar jointed goatgrass populations, yielded higher, and had less contamination and was therefore more competitive with jointed goatgrass than wheat planted in October, observed through a reduction in jointed goatgrass propagule production. Planting wheat in October, for the purpose of controlling jointed goatgrass through additional tillage, proved ineffective. Jointed goatgrass population densities were not reduced in experiment one, and only slightly reduced in experiment two. The dramatic loss of yield, associated with the later plantings, far outweighs any benefits gained by delaying wheat planting.

En France, depuis plusieurs années, la surface cultivée en pois diminue notablement. Une des causes est la forte instabilité des rendements des variétés de printemps, qui représentent 90% de la sole, liée à de nombreux facteurs limitants: état structural tassé à cause de conditions trop humides au semis et, stress hydriques et thermiques de fin de cycle. Dans l'objectif de relancer cette culture, de nouvelles variétés de pois d'hiver, très réactives à la photopériode et relativement résistantes au gel, sont actuellement en cours de sélection. Ces variétés peuvent être semées dès début octobre, ce qui devrait réduire à la fois les risques de tassement du sol lors du semis et de stress hydriques et thermiques du fait d'un avancement de la période reproductrice au printemps. Ces avancements sont a priori favorables à une meilleure stabilité de la production. Cependant, le début de l'automne est une période de travail chargée dans les exploitations agricoles et il est possible que les semis de ces nouvelles variétés ne soient pas réalisés dans les conditions optimales permettant d'extérioriser leurs avantages. Le changement de dates de semis, induit par l'utilisation de ces variétés, pourrait par ailleurs avoir des répercussions sur le bilan d'azote et la consommation d'eau de la culture. L'objectif général de ce travail a été de mettre au point une méthode afin d'évaluer, avant leur mise sur le marché, les intérêts agronomiques et environnementaux de ces nouvelles variétés et de déterminer les caractéristiques qu'elles devraient réunir pour garantir ces avantages. L'étude a été conduite en trois étapes. Tout d'abord, quatre expérimentations (2 lieux x 2 années) ont été réalisées afin de déterminer les effets de l'état structural, de la période de semis et de la variété sur les fonctionnements aérien et racinaire d'une culture de pois. Dans un second temps, les résultats de ces expérimentations, associés à des jeux de données extérieurs, ont permis de compléter et d'évaluer un modèle dynamique de culture de pois simulant le rendement, la teneur en protéines des graines, la part d'azote issue de la fixation, le bilan d'azote et la consommation d'eau à l'échelle de la culture. Ce modèle a ensuite été utilisé pour évaluer différentes variétés virtuelles candidates. Dans cette dernière étape, le modèle de culture a été couplé à un modèle d'organisation du travail à l'échelle de l'exploitation agricole, afin de déterminer, en tenant compte des contraintes d'organisation du travail des chantiers d'automne, les périodes de semis possibles pour les variétés de pois. En fonction de ces périodes de semis, on a simulé, grâce à un modèle d'évolution de l'état structural du sol, les risques de tassement sous les cultures de pois et les conséquences sur la production. Des connaissances nouvelles ont été produites sur le développement du système racinaire, pour différentes conditions de semis et de structure du sol. Un modèle de culture adapté aux variétés et aux semis d'hiver, prenant en compte la variabilité de disponibilité d'azote et de la structure du sol, est maintenant disponible. Enfin, l'utilisation combinée des modèles a permis de montrer que les résultats des évaluations des variétés virtuelles sont différentes selon que l'on prend on non en compte les contraintes existant au niveau du système de culture. L'ensemble de ce travail permet de proposer aux sélectionneurs des idéotypes variétaux présentant un intérêt agronomique et environnemental dans des exploitations agricoles de grande culture