The objectives of this study are to 1) qualitatively and quantitatively measure the odor-active compounds in ‘Marion’ blackberry; 2) compare the aroma profiles of advanced selections and new cultivars of thornless blackberry cultivars with ‘Marion’; 3) study the development of furaneol in ‘Marion’ during ripening and; 4) investigate the distribution...
Blackberries have been enjoyed for their delicious flavor and high nutritional value for hundreds of years. In North America, blackberries were cultivated since 1850-1860. Blackberries have their characteristic and unique aromas depending on the cultivar and growing conditions. The objective of this study was to evaluate the impact of seasonal...
The water status of grape vine throughout the growing season is a primary determinant of vine vigor and berry composition. The concentrations of volatile compounds and precursors in grape berries are highly influenced by viticultural practices. Imposing a water deficit on the vine during berry development is an important vineyard...
Cheddar Cheese samples (good cheese, weak cheese, cheese made with pasteurized milk, cheese made with heat-shocked milk, cheese from production plant A, cheese from production plant B, cheese made with adjunct culture, and cheese made without adjunct culture), were evaluated during the ripening stage. Proteolysis was studied by a fractionation...
Wine volatile composition is one of the most important components of wine quality, and it is greatly affected by multiple factors, including grape variety, viticultural practices, and winemaking procedures. Pre-fermentation cold soak is one of the winemaking techniques widely undertaken by winemakers to modify their red wine quality. Imposing a...
Three analytical methods for determination of aroma compounds in alcoholic beverages were developed and validated. These methods are sensitive and reliable that can be applied to analyze volatile phenols, stale aldehydes as well as some highly volatile aromas in alcoholic beverages. In the first study, an ethylene glycol (EG) polydimethylsiloxane...
Grapevine red blotch virus (GRBV) is a single-stranded DNA virus that causes grapevine red blotch disease (GRBD). Symptoms of GRBD include red discoloring of leaf margins and red veins on the underside of the leaves. GRBD affects the plant's metabolism and photosynthetic pathways, and disrupts carbon translocation and chlorophyll concentrations....
'Marion' and 'Thornless Evergreen' blackberry volatiles were analyzed by capillary gas chromatography-flame ionization detection (GC-FED) and GC-mass spectrometry (GC-MS). Based on total percentage of FID area 'Thornless Evergreen' contains significantly more alcohols, hydrocarbons, and phenols than the 'Marion'; 'Marion' contains more acids and esters. Both cultivars contained comparable amounts of...
It is often perceived that late maturity of grape gives a more complex aroma
profile to Pinot noir wine, however, there is little understanding of the basic flavor
chemistry of grape maturity on wine aroma. The aroma contributing compounds in
Pinot noir were first identified by aroma extract dilution analysis...
The objectives of this study were to 1) measure and compare the compositional differences of essential oil among three hop cultivars ('Centennial’, 'Citra' and 'Nelson Sauvin'), 2) identify the odor-active aroma compounds in three varieties of hops and 3) investigate the behavior of hop-derived aroma compounds in beers prepared by...
Constituents of the wine matrix, including ethanol, affect adsorption of sulfur volatiles on solid-phase microextraction (SPME) fibers, which can impact sensitivity and accuracy of volatile sulfur analysis in wine. Several common wine sulfur volatiles, including hydrogen sulfide (H2S), methanethiol (MeSH), dimethyl sulfide (DMS), dimethyl disulfide (DMDS), dimethyl trisulfide (DMTS), diethyl...
High vegetative growth of Pinot Noir vine is a common problem in most vineyards of Oregon's Willamette Valley, where sunlight exposure and heat accumulation are limited. Consequently, growers in this region commonly use vineyard management strategies to regulate vine vigor and improve grape and wine quality. Wine quality is greatly...
Wine volatile composition is one of the most important constitutes of wine quality, and it is greatly influenced by number of factors. The studies herein were conducted to evaluate the grape and wine aroma affected by different vine nutrient status, vigor and crop levels of Oregon Pinot noir.
In the...
The production of high-quality wine is an important target for wineries worldwide, and low crop level (yield) has been one vineyard management criterion long believed to achieve wine quality. Low yields are most often achieved by removing clusters from the grapevine. Some studies show that cluster thinning can enhance grape...
Raspberries have been popular since the time of the ancient Greeks. Red raspberries are cultivated throughout the world, particularly in the Pacific Northwest region of the United States and Canada. The raspberry bushy dwarf virus (RBDV) causes significant reduction in yield and crumbly fruit in raspberries, blackberries and raspberry-blackberry hybrids....
Ultra high temperature (UHT) processing can extend shelf life of milk to several months without refrigeration, which is more convenient and energy saving than pasteurized milk. However, the poor acceptance caused by "cooked" flavors limits its marketing growth, especially in United States. Ohmic heating, which has a more uniform and...
Five genotypes from California (Ventana, Caniarosa, San Miguel, 13G97, and Venice) and Oregon (Totem, Puget Reliance, Puget Summer, Hood and Independence) were evaluated for quality. The volatile compounds were analyzed using head space solid phase micro extraction-gas chromatography-flame ionization detection (GGFID) and gas chromatography-mass spectrometry (GC-MS). Odor activity values of...
Milk is the first source of nutrition for all mammalian neonates. The complex matrix that constitutes milk has evolved to provide optimal nutrition for the newborn, for each species, respectively. Milk fat, originating in mammary epithelial, forms lipid droplets which are stabilized in the aqueous environment by bioactive polar lipids...
This study first investigated the developmental changes in the volatile composition and carotenoids of Pinot noir grapes. Grape berries were sampled every week from pea size to harvest during the 2011 and 2012 season. Carotenoids and organic acids were analyzed by HPLC. Volatile compounds were extracted from crushed berries using...
The milk fat globule membrane, a major component in buttermilk, contains many complex lipids known to be involved in a variety of biological processes. Phospholipids, including sphingolipids, exhibit antioxidative, anticarcinogenic, and antiatherogenic properties and have essential roles in numerous cell functions. Filtration coupled with supercritical fluid extraction (SFE) may provide...
Objective(s) of Proposed Research or Outreach Project:
1. Investigate cover crop management in commercial vineyards on aroma and aroma precursor composition in grapes.
2. Investigate cover crop management in commercial vineyards on flavor quality of wine.
3. Investigate the feasibility to use aroma and aroma precursor analysis in grapes as...
The objective of this study was to identify aroma volatiles in sweet whey powder. Volatiles were isolated by solvent extraction and solvent assisted flavor evaporation. Fractionation was followed to separate acidic volatiles from nonacidic volatiles. Gas chromatography/olfactometry and gas chromatography-mass spectrometry were used for the identification ofaroma compounds. Osme methodology...
The aroma of milk has been often defined as bland and pleasant, yet characteristic. Conventional thermal processing of milk can certainly extend shelf life, but inevitably changes its flavor. High pressure processing has been suggested as an alternative for milk pasteurization with improved fresh flavor retention. The objective of this...
Vineyard management strategies, including vineyard floor management and crop level management, can be used to influence vine vigor and fruit composition. Two studies were conducted to evaluate the impact of these practices on Pinot Noir in Oregon's Willamette Valley. Managing crop levels is common in cool climate vineyard production though...
This work set out to examine whether ethanol content can influence the human detection of volatile hop compounds in beer. Advances in chromatography have identified hundreds of chemical compounds in the essential oil of hops but only a fraction are directly associated with "hoppy" aroma. To screen compounds, sensory detection...
With the rapid growth of worldwide internet traffic in data centers and clouds, silicon photonics has been utilized to provide enormous data bandwidth and outstanding energy efficiency over electronics. Computing servers and storage servers that are connected by communication links are relying more on optical rather than electrical means mainly...
The objectives of this project were to investigate the chemical composition of five varieties of wine grape pomace (WGP) skins obtained in the Pacific Northwest of the United States with the emphasis on dietary fiber (DF) and polyphenolic compounds, and further to evaluate the feasibility of developing WGP extract based...
Wine aroma is one of the most important aspects of wine quality and yeast contribute a significant amount of the volatile aroma compounds in wine. However, our understanding of the contribution of specific yeast to Pinot noir aroma is still limited. In particular, the contribution of non-Saccharomyces yeast species present...
Color stability and flavor are two of the most important aspects of red wine quality. The development of anthocyanins and tannins in Pinot noir grapes and their relative importance in wine has been under investigation by Dr. James Kennedy. Flavor development, however, is not well understood. Several gas chromatography/olfactometry techniques...
Aroma potentials in early and late maturity Pinot noir grapes were investigated in two
consecutive vintages. The grape samples were hydrolyzed under acidic conditions and the
released odorants were studied by aroma extract dilution analysis (AEDA). Forty-nine
main odor-active compounds were detected in the AEDA. The odorants released with
high...
Developmental changes in the carotenoids and volatile compounds of Pinot noir grape berries were investigated in this study from pea size to harvest during 2012. HPLC analysis showed continued decrease of lutein, β-carotene, neochrome a and neoxanthin continued to decrease during berry development, with rapid decrease of lutein and (9′z)-neoxanthin...
While previous research has suggested that bitterness is the key determinant of vegetable disliking, it is unknown what role odor plays in vegetable hedonics. We therefore investigated the impact of odor as well as taste on liking and disliking of four vegetables (steamed asparagus and Brussels sprouts; fresh celery and...
When a person is tasting wine, they first evaluate the appearance and then the aroma. The smell of wine is a crucial part of tasting and the aromas emanating from the wine should be pleasant. Aroma quality perceived in wine is determined by multiple interactions of the components found in...
The skins of two white wine grape pomace (WWGP) and three red wine grape pomace (RWGP) from US Pacific Northwest were analyzed for their dietary fiber (DF) and phenolics composition. DF was measured by gravimetric-enzymatic method with sugar profiling by HPLC-ELSD. Insoluble DF composed of Klason lignin (7.9-36.1% DM), neutral...
'Marion' blackberry is known for having excellent aroma and flavor, yet they are susceptible to damage by freezing and they are very thorny. Thornless blackberry cultivars have been developed and show great potential. Thus, the interest of the study was in determining which of eight thornless blackberry cultivars, have similar...
This research investigated yeast populations and diversity during pre-fermentation cold maceration and alcoholic fermentation of Vitis vinifera L. cv. Pinot noir grapes from a commercial vineyard (Dayton, OR). Fermentations were conducted at the Oregon State University research winery in 100 L tanks while grapes from the same vineyard lot were...
Hops (Humulus lupulus L.) are primarily used to provide specific characteristics to beer, such as bitterness, aroma, flavor, and microbial stability. The chemical composition of hops, relative to how they are used during the brewing process, dictates the expression of these characteristics. Of the raw ingredients that go into making...
The fermentation of honey-based musts has been a feature of civilization for millennia. Typically comprised of 75-90% (w/w) simple (i.e. fermentable) sugars, the glucose and fructose present are readily fermented by either pitched or adventitious micro-organisms. Nevertheless, despite its venerable heritage, honey-based fermentations are prone to inconsistency, and it is...
This work set out to examine the methodologies of dry hopping, compare different hop materials, and look at the extraction behavior of different types of hop compounds. This work consists of two discrete studies, where the first study informed the design of the second.
The first study measured the concentrations...
Wine grape pomace (WGP), the byproduct from winemaking, is a good source of polyphenols and dietary fibers, and may be utilized as antioxidant dietary fibers (ADF) for food applications. The objectives of this thesis research were to first determine the phenolic compounds, antioxidant and antimicrobial activities in red WGP under...
Polycyclic aromatic hydrocarbons (PAHs) are environmental contaminants produced mainly from the incomplete combustion and pyrolysis of organic matter. PAHs are among the major contaminants at over 800 Superfund sites, nationwide. Thermal remediation is used as a method to remediate soils contaminated with PAHs through the use of heat to mobilize...
Cold soaking is a technique used during red winemaking to alter the aroma, flavor, and phenolic content of a wine. However, cold soaking does not come without risk, as this process can result in the production of spoilage compounds such as acetic acid and ethyl acetate if excessive growth of...
Continued interest in the development of miniaturized and portable analytical platforms necessitates the exploration of sensitive methods for the detection of trace analytes. Nanomaterials, on account of their unique physical and chemical properties, are not only able to overcome many limitations of traditional detection reagents but also enable the exploration...
The effect of deficit irrigation and a kaolin-based, foliar reflectant particle film (PF) on grape composition and volatile compounds in Merlot grapes was investigated over two growing seasons in semi-arid, south-western Idaho. Vines were provided with differential amounts of water based on their estimated crop evapotranspiration (ET[subscript c]) throughout berry...
Pre-fermentation cold soak is a winemaking technique used to alter the color, mouthfeel, and aroma of red wine. While it is still debated what impact cold soak has on these wine quality parameters, current thoughts are that resident yeast populations found in fresh grape must play a role in altering...
One of the most common problems in wine production is the formation of hydrogen sulfide (H₂S) and other volatile sulfur compounds (VSCs), which can mask positive aromas at low concentrations and result in unpleasant aromas such as rotten egg, cabbage, garlic, and rubber at higher concentrations. Despite the large body...
Hop aroma in beer is related to the unique compositional chemistry of the hops used in the brewing process. While the range of these compositions is quite diverse and primarily dependent on hop cultivar¹, other studies have also shown that cultivation, seasonality, harvesting², processing³⁴, and storage practices⁵⁶ contribute to differences...
When hops are added to beer, varying degrees of hoppy aroma persist in the finished beer as a result of a number of factors. Dry-hopping is a technique whereby hops are added to beer post-fermentation to leverage the maximum aroma potential of the hop essential oils while minimizing bitterness contribution...
Tethering fluorophores on metal nanoparticles for metal enhanced fluorescence (MEF) has attracted a lot of attention from scientists interested in fluorescence based approaches. MEF has many benefits in fluorescence related techniques, because the analytical signal increases and enables potentially lower detection limits or better sensitivity. Many types of nanoparticles have...
Malolactic fermentation (MLF) is an important step in the production of wines and is commonly performed in red or cool climate wines to reduce acidity. In this study the impact of MLF on red wine color and the ability of Oenococcus oeni to degrade compounds important to the development of...
Scombroid poisoning, caused by histamine intoxication, is one of the most prevalent illnesses associated with seafood consumption in the United States. The illness is usually accompanied with a variety of symptoms, such as rash, nausea, diarrhea, flushing, sweating, and headache. Incidence of scombroid poisoning has been consistently reported in the...
There is limited information available on production of trailing blackberry, particularly certified organic plantings, which are of interest to growers as there is increased consumer demand and a price premium over conventionally-produced fruit. Various production strategies were evaluated for their effect on yield, biomass production, carbon (C), and nutrient concentrations...
Monoterpenes are important volatile compounds to the aroma of many white wines. Many monoterpenes are chiral and found in wine as different isomers. These isomers (also known as enantiomers) are non-superimposable mirror images of each other, maintain the same molecular structure and in many instances possess different sensory characteristics. Much...
Malolactic fermentation (MLF) is important in the production of wines as it reduces acidity through the conversion of malic acid to lactic acid. However, successful MLF can be difficult to achieve due to yeast antagonism of the bacterium responsible for
the secondary fermentation, Oenococcus oeni. In particular, yeast produced sulfur...
Many pesticides, polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers
(PBDEs), and polycyclic aromatic hydrocarbons are persistent, bio-accumulative, and
toxic. These semi-volatile organic compounds (SOCs) can undergo atmospheric
transport and deposition in cold, remote ecosystems. A better understanding of their
accumulation in the fish of these ecosystems is important to better predict...
Nitrogen (N) is the most important nutrient to manage in the overall wine production system, since N has a large influence on vine productivity and fruit quality in the vineyard and also on fermentation kinetics and fermentation-derived aromas in the winery. Previous studies investigated the influence of either vineyard N...
Analytical chemistry is an area of chemistry primarily focused on the study and use of instruments for separation, identification, and quantification of an analyte of interest. Specifically, separation science within analytical chemistry often refers to the process of dividing mixtures into their small component parts based on differences in their...
Many volatile compounds generated during the thermal processing of milk have been associated with cooked, stale, and sulfurous notes in milk and are considered as off-flavor by most consumers. A headspace solid-phase microextraction (HS-SPME)/gas chromatographic technique for the quantitative analysis of thermally derived off-flavor compounds was developed in this study....
The objectives of this research project are to gain a better understanding of juice/must nutrition and the production of hydrogen sulfide and other 'off' sulfide odors in Oregon wines in relationship to both viticulture and winemaking practices. Specifically, the objectives of this research project are: · To analyze commercial juices/musts...
Laboratory screening bioassays and field trapping experiments of spotted wing drosophila flies, Drosophila suzukii (Matsumura) (Diptera: Drosophilidae), were conducted to determine the attractiveness of 17 compounds as well as to compare attractant efficiency during peak fruit ripeness and postharvest captures late in the season. Compounds structurally related to each of...
Our latest edition of the OWRI Technical Newsletter contains research updates and a comprehensive list of publications summarizing research conducted by faculty of the Oregon Wine Research Institute at Oregon State University. Dr. R. Paul Schreiner, USDA-ARS Research Plant Physiologist, opens the newsletter with a research update on Pinot noir...
Our latest edition of the OWRI Technical Newsletter contains research updates, the latest Extension resources, and a comprehensive list of publications outlining research conducted by members of the Oregon Wine Research Institute at Oregon State University. Dr. Patty Skinkis, Viticulture Extension Specialist & Associate Professor, OSU opens the newsletter with...
Novel donor-typed ternary graphite intercalation compounds (GICs) are synthesized and characterized containing (1) pyrrolidinium cations with DMSO co-intercalates; (2) alkali metal cations with crown ether co-intercalates; and (3) alkali metal cations with polyethylene glycol co-intercalates. Structural and compositional data are obtained for the stable products. A new ether-amine co-intercalate exchange...
Novel graphite intercalation compounds (GICs) and associated chemistry have been explored, specifically: (1) containing alkyl- substituted imidazolium cations; (2) a series containing alkaline earth metal (Mg, Ca, Sr, Ba) cations with ethylenediamine (en) co-intercalates; (3) showing reversible intragallery M-M bonding and (4) via electrochemical intercalation of Mg cations with potential...
Novel synthetic strategies are developed to prepare new intercalation compounds and nanocomposites with several layered hosts (NiPS₃, Na-montmorillonite, MoS₂ and MoO₃). In these products, alkali metals are ionic intercalates and linear polymers, dendrimers or amines act as co-intercalates. In addition to new synthetic approaches, new structures are identified and characterized....
Substantial scientific investment has been directed towards understanding factors that influence distribution patterns and animals' remarkable ability for precise orientation and navigation, yet fundamental gaps in our knowledge remain. In my dissertation, I applied emerging genetic technologies to conduct a top-down and bottom-up investigation of animal movement and cue perception....
Forest managers of public lands in western Oregon and Washington have become increasingly interested in creating additional conifer cohorts in young, even-aged, second-growth Douglas-fir stands. The purpose of our research was to assess the establishment, survival, and growth of naturally-regenerated and underplanted conifers 10-13 years after overstory thinning and understory...
The use of size and shape tunable quantum confinement nanocrystals has many potential applications for use in semiconductors, optics and sensors. The synthesis of lead sulfide (PbS) and copper indium diselenide (CuInSe₂) nanoparticles are of particular interest for use in semiconductor, optoelectronics and bio-medical applications.
The continuous synthesis of lead...
Seeds from 30 species of grasses and forbs native to Pacific Northwest prairies were tested for physical and physiological dormancy. The physical dormancy was determined by mechanically and chemically scarifying seeds. Physiological dormancy was evaluated with cold stratification before germination. Experiments were analyzed individually with ANOVA analysis, and by seed...
Native plants provide many ecosystem services while also having great beauty and are a valuable component of the landscape. As use of these plants in habitat restoration, agricultural insectary plantings, and home landscapes increases so does demand for information on the basic biology of a group of species that have...
The current knowledge on the microstructural evolutions and mechanical properties of selective laser melting (SLM) produced H13 tool steel components is limited. This research is focused on optimization of SLM processing parameters for H13 tool steel and investigation of microstructure and mechanical properties of H13 tool steel components after SLM...
In this work we present a multiagent Fleet Coordination Problem (FCP). In this formulation, agents seek to minimize the fuel consumed to complete all deliveries while maintaining acceptable on-time delivery performance. Individual vehicles must both (i) bid on the rights to deliver a load of goods from origin to destination...
There are numerous techniques for improving the mixing of fuel and
oxidant species. However, many of these methods cannot be applied to combustion
systems due to material limitations. A means of mixing the reacting species without
physically invading the flow stream is therefore desired.
In this work, induced electromagnetic forces...
Marine sediments are one of the largest habitats for microbial life on earth. These microorganisms play critical roles in biogeochemical cycling both within the subsurface and between the sediment and water columns. However, microbial communities in sediments are highly heterogeneous and the factors defining microbial community structure and metabolic function...
This dissertation focused on data mining in food science research and on the technical functional properties of wheat straw-derived biorefinery-byproduct fiber preparations as related to potential applications as food ingredients. This first study evaluated the importance of electronic bibliographic database selection and multiple database usage during the information retrieval phase...
Polycyclic aromatic hydrocarbons (PAHs) are a class of contaminants ubiquitous in the environment and result from the incomplete combustion of fossil fuels. Many PAHs have been identified as procarcinogenic, and are metabolized to form DNA adducts; however, other mechanisms also may contribute to toxicity and help explain differences in toxicity...
Beer brewing, broadly speaking, consists of two stages, a hot side and a cold side. The hot side occurs in the brewhouse and consists of steeping malted grain in hot water to extract sugars, separating the steeping liquid (wort) from the solids, and boiling the wort with an addition of...
The variety of natural disasters provide different sets of characteristics and properties with unique challenges. One significant difference between hazard types is prewarning lead time, the amount of time individuals have from a potential warning to the disaster occurring. Rapid onset disasters may not provide an official warning about a...
Cnidarians, such as corals and sea anemones serve as hosts to a variety of organisms including symbiotic dinoflagellates, bacteria, virus, and apicomplexans. As corals are vital to the health and productivity of the reef ecosystem it is important to understand how these organisms interact with each component of the holobiont....
According to conventional wisdom, hops are treated in the brewery as biologically inactive ingredients, added to wort or beer primarily as a flavoring agent. In the past, hops were used in relatively small quantities, with the majority of hop additions made to boiling wort. Converse to traditional hopping practices, modern...
The seafood industry has a problem of underutilization of harvested and processed fish. Up to 60% of the weight of the fish is considered a byproduct that is typically made into fishmeal for livestock and aquaculture feed, a low-value and non-food grade product. Two species that make up major fisheries...
The human senses can be used as analytical tools to evaluate many different aspects of our daily lives. The use of our senses through organoleptic methods offers unique and powerful insights into the characteristics of different stimuli. Due to the unique function of the different sensory organs we use to...
The spatial and temporal patterning of sequence specific transcription factors (SSTFs) contributes to cell type specification and organ formation during embryogenesis. Homeodomain transcription factors are evolutionally conserved among invertebrate and vertebrate animals. They are responsible for body segmentation and organogenesis. Lbx1 and Pitx2 both are homeodomain transcription factors contributing to...
The overall goal of this study was to utilize apple pomace, the byproduct from juice processing, as a renewable source of fiber to create sustainable packaging using molded pulp technology. The goal was accomplished through two studies: 1) to modify apple pomace fibers for increasing relative cellulose composition and improving...
In short, the brewing process uses hot water to extract fermentable sugars from malt to make a wort that is bittered by hops and finally fermented by yeast to produce beer. The four key ingredients in brewing are malt, water, hops, and yeast. Malt is perhaps the key ingredient, as...
Only two genome-wide significant loci associated with longevity have been identified so far, probably because of insufficient sample sizes of centenarians, whose genomes may harbor genetic variants associated with health and longevity. Here we report a genome-wide association study (GWAS) of Han Chinese with a sample size 2.7 times the...
Full Text:
, Han-Ming Wang
8
, Jie Dong
8
, Gu-Yan Zheng
8
, Li Lin
5
, Feng Qian
5
, Yanwei
Qi
3,9
, Xiao
Only two genome-wide significant loci associated with longevity have been identified so far, probably because of insufficient sample sizes of centenarians, whose genomes may harbor genetic variants associated with health and longevity. Here we report a genome-wide association study (GWAS) of Han Chinese with a sample size 2.7 times the...
Full Text:
Christiansen20,
Kaare Christensen20, Claudio Franceschi21, Michael W. Lutz15, Jun Gu16, Qihua Tan20,
Thomas
Only two genome-wide significant loci associated with longevity have been identified so far, probably because of insufficient sample sizes of centenarians, whose genomes may harbor genetic variants associated with health and longevity. Here we report a genome-wide association study (GWAS) of Han Chinese with a sample size 2.7 times the...
The enantioselective total synthesis of quinolizidine-containing natural product cermizine D and formal syntheses of senepodine G and cermizine C has been achieved. These natural products are members of the lycopodium alkaloids, which have attracted significant attention due to their exciting biological activities and the diverse structural scaffolds. Key steps in...
Parasitic infections and immune challenges can affect host reproductive fitness and, ultimately, the evolution of host populations in a myriad of ways. The fitness implications of parasitic infections range from increased host mortality to subtle changes in reproductive investment. From alterations of behaviors, sexual signaling, and competitive ability to changes...
The synthesis of isoindazoles bearing α-ketoester and α-hydroxyester groups via the coarctate cyclization of ester terminated azo-ene-yne precursors is described. Whereas previous studies on isoindazole formation have shown the reaction to proceed through a kinetic coarctate pathway, functionalization of the terminal acetylene with a methyl ester sufficiently stabilizes the carbene...
H13 components with a relative density of ∼99% were additively manufactured using the selective laser melting (SLM) process. The highest density part (relevant density 99%) with the lowest level of porosity (<0.01%) was made with a volumetric energy density of 760 J/mm3 (152 W laser power, 100 mm/s scanning speed,...
In a multilevel study to determine limits to underplanted conifer seedling growth, Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco), grand fir (Abies grandis (Dougl. ex D. Don) Lindl.), western redcedar (Thuja plicata Donn ex D. Don), and western hemlock (Tsuga heterophylla (Raf.) Sarg.) seedlings were planted beneath second-growth Douglas-fir stands that had...
Vertically shoot positioned (VSP) training systems are common in Oregon's Willamette Valley, where deep fertile soils and high regional precipitation task growers with curbing vegetative vigor within this system. Management strategies, such as canopy hedging and cluster-zone leaf removal, are used to improve microclimate within the canopy and around the...
The development of a transient electric birefringence (TEB) apparatus for macroparticle characterization is herein discussed. The experimental difficulties encountered were related largely to poor data resolution. Misalignment and strain birefringence in optical components further complicated results. Improved data digitization methods were developed, and precise mathematical models were derived in order...
Azaspiracid has generated an enormous amount of scientific interest in the fourteen years since its initial discovery. The structure contains a 6,5,6 bis-spiroketal, a [3.3.1] bicyclic ketal and a 6,5-spiroaminal linkage as key moieties. With 9 rings, 20 stereocenters and three alkenes, the azaspiracid immediately attracted the interest of the...
Oxidative stress occurs when the balance between reactive oxygen species and antioxidant defense mechanisms in the body becomes tipped heavily in favor of the reactive oxygen species. Reactive oxygen species can be present in excess due to elevated O2 levels, radiation, infection, smoking, or even excessive exercise. It is also...