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First-Year Stand Development Of Subtropical Grass Seedlings And Influence By Initial Plant Density, Bruce Anderson, L E. Moser

IGC Proceedings (1977-2023)

Stands of subtropical grasses develop slowly in mid-continent North America and this may be due partly to initial plant density. Panicum virgatum L. and Andropogon gerardii Vitman seedlings were transplanted from a greenhouse into field plots as pure stands in equidistant spacings at initial plant densities of 2.5, S, 10, 20, 40 and 80 plants/m1. P. virgatum produced higher yields, fewer tillers/plant and leaves/tiller, less basal density and shorter plants than A. gerardii during the first year of growth. Light interception was higher and soil temperatures lower for A. gerardii. Basal density and height increased while tillers/plant decreased …

Use Of Natural 15n Abundance In Estimating Nitrogen Fixation By Centrosema Spp: Influence Of Phosphorus And Strain Of Bradyrhizobium, G Cadisch, S F. Ledgard, J Noseberger, R Sylvester-Bradley

IGC Proceedings (1977-2023)

Isotopic ¹⁵N fractionation during N2 fixation by Centrosema acutifolium, C. brasilianum and C. macrocarpum grown in N·free sand-nutrient solution was investigated as a prerequisite for the use 9f the natural ¹⁵N abundance method to estimate N2 fixation. The natural abundance of ¹⁵N was always lower in shoots than in roots and nodules, and there was little difference between species. In contrast, inoculation strongly influenced isotopic fractionation, leading to average o15N shoot values of -0.64 and -1.37 for Bradyrhizobiumstrains CIAT3101 and 1670 respectively, given adequate phosphorus. P deficiency led to a small legume x P interaction …

Importance Of Legume Nitrogen Fixation In Sustainability Of Pasture In The Cerrados Of Brazil, G Cadisch, E F. Carvalho, A R. Suhet, L Vilela, W Soares, J M. Spain, S Urquiaga, K E. Giller, R M. Boddey

IGC Proceedings (1977-2023)

A pure Andropogon gayanus sward was compared with a Stylosanthes spp.-A. gayanus mixed sward in order to assess the benefit of introducing N2-fixing legumes on the long-term sustainability of grazed pastures. There was no difference between the total dry matter and animal production of the 2 pastures, although the legumes fixed 67-117 kg/ha of N in 1991 with 80% of the legume N obtained from N2 fixation. Litter deposition was 20-35% greater in the mixed sward and the % N in this litter was also higher, leading to twice the amount of N mineralised in the 0-5 cm …

Attainment And Distribution Of Competitive Equilibrium In Tropical Grass-Legume Mixtures, P G. Tow

IGC Proceedings (1977-2023)

An experiment under controlled conditions, using the de Wit competition model, has provided an explanation of competitive relationships in mixtures of Panicum maximum var. trichoglume (green panic) cv. Petrie and Neontonia wightii cv. Tinaroo glycine. Experiments in a tropical upland environment with summer rainfall dominance (to which they ore adapted) have provided further understanding of their relationships. Over a period of 2 years for well-wafered plants in containers and 4 years in a rain-fed field experiment, competitive gains by one species alternated with-gains by the other, and neither species gained significantly overall. Gains by the grass were favoured by …

Managing Woody Weeds In Grazing Ecosystems: Application For Tropical Woodlands Of North-Eastern Australia, Joel R. Brown, John G. Mcivor, Andrew J. Ash

IGC Proceedings (1977-2023)

Shrub invasion of tropical woodlands is reducing the viability of native ecosystems as well as the livestock industry, After shrub invasion, forage supply is reduced and over-grazing and soil erosion are exacerbated. We propose a non-equilibrium model of the system and use that model to develop hypotheses and design experiments to test both competition- and disturbance-based management regimes. This model proposes that disturbance in the form of burning is the primary limiting factor in excluding and limiting shrub seedling establishment and suggests that management decisions focus on maintaining adequate herbaceous biomass for a burning regime that limits woody plant success.

Fire And Grazing Interact To Manipulate Pasture Composition In Heteropogon Contortus (Black Speargrass) Pastures, D M. Orr, C J. Paton

IGC Proceedings (1977-2023)

Aristida spp, (wiregrasses) are invading areas of Heteropogon contortus (black speargrass) pastures in southern Queensland. Interim results from 2 field experiments indicate that increasing the frequency' of annual spring burning over 3 years, with and without grazing, results in a progressive reduction in the yield of Aristida spp. H. contortus yields also increased with increasing frequency of burning under non-grazing but not when grazed, H. contortus yields have increased after burning when grazing has been deferred or where the stocking rate has been halved after the fire. The results suggest that botanical composition in these pastures can be manipulated readily …

Impact Of Grazing Pressure On The Plant Population Dynamics Of Heterpogon Contortus (Black Speargrass) In Subtropical Queensland, D M. Orr, C J. Paton

IGC Proceedings (1977-2023)

Heteropogon contortus is a palatable pasture grass which is being threatened by , increases in grazing pressure, particularly during drought. This paper presents interim results plant population dynamics of H. contortus., as affected by stoc.1s tak. legume augmentation (mainly Stylosanthes sabra cv. Seca) and p1 Jvision of a dry-season supplement for cattle. The study began in 1%8. By 1991, basal ara of H. co11tortus was highest at the light .. Jt stocking rate of 0.187 steers/ha and declined linearly to be longest at the heaviest stocking rate of 0,5 steers/ha. Similarly, survival of the H. contortus tussocks initially present …

Seca Stylo (Stylosanthes Scabra Cv. Seca) Populations Increase Faster Under Light Grazing, D M. Orr, C J. Paton

IGC Proceedings (1977-2023)

Augmentation of native pastures with legumes such as Stylosanthes scabra can increase cattle live-weight gain relative to that from native pasture. In the longer term, however, Stylosanthes spp, density can increase and populations of native grasses may become unstable. This paper reports interim results from a study aimed al monitoring changes in the density of S. scabra cv. Seca in relation to stocking rates, The density of Seca monitored in permanent quadrats increased from 15 plants/m2 in 1988 to 100 and 25 plants/m2 in 1992 at 0.25 and 0.5 beasts/ha respectively. These increases resulted from both the survival of the …

Clover-Based Pasture Systems For Intensive Sheep Production In The Central Highlands Of Papua New Guinea, S Sivasupiramaniam, A K. Benjamin, J Pitala

IGC Proceedings (1977-2023)

This paper describes some of the studies that have been conducted since 1985 to develop clover-based pasture systems for intensive sheep production in the central highlands of Papua New Guinea. The clovers tested were Trifolium repens cv. Haifn (Haifa white clover) and Trifolium semipilosum cv. Safari (Kenya white clover). They were sown together, with setaria (Setaria sphacelata cv. Nandi) and signal grass (Brachiaria decumbens cv. Basilisk) at Menifo (1400 m asl) and with setacia and kikuyu (Pennisetum clandestinum cv. Whittet) at Tambul (2240 m) and Yogos (1950 m) in the central highlands. At Menifo, when rotationally grazed …

An Integrated Approach To Soil-Plat-Animal Interactions On Grazed Legume-Based Pastures On Tropical Acid Soils, M J. Fisher, C E. Lascano, R J. Thomas, M A. Ayarza, I M. Rao, G Rippstein, J.H M. Thornley

IGC Proceedings (1977-2023)

Legume-based pastures developed by the Tropical Pastures Program (TPP) of CIAT give spectacular increases in both stocking rates and animal live-weight gains on the savannas of Latin America, A team within the TPP is addressing the problems of their management for legume persistence and soil-plant-animal interactions, using as Its focus a grazing experiment on 2 oxisols of contrasting texture on the Colombian Llanos. The objective is to model the pastures to forecast the effect of management options on long-term persistence and nutrient cycling in grazed legume•grass associations in the Latin American savannas.

Persistence Of Roundleaf Cassia In Grazed Pastures - A Conceptual Model, R M. Jones, C K. Mcdonald, G A. Bunch

IGC Proceedings (1977-2023)

Roundleaf cassia (Cassia rotudifolla) cv. Wynn is a short-lived perennial that relies on seedling recruitment for long-term persistence. Its persistence is considered in terms of survival of plants from the initial sowing, seed set, seedling recruitment, run-down of reserves of soil seed, and survival of seedlings. The major factor controlling all these stages is soil moisture stress; grazing management 'is less important. A conceptual model of Wynn persistence is presented and progress in mathematical modeiling is reported.·

Variation In Hydrological Characteristics Of The Soils Associated With Grazed Patches In Granitic Landscapes In Northern Australia, M M. Sallaway, D Waters, B Bridge, F P. Wandera

IGC Proceedings (1977-2023)

Under medium to heavy grazing of black speargrass (Heteropogon contortus) landscapes of south-east Queensland, "patchiness" has developed with a change from H. contortus to Aristida spp., Cllrysopogo11 spp. or a,inual grasses. This grazed patch development is associated with changes in soil hydrological characteristics which in turn affect runoff and soil erosion. T!\e soil hydrologic properties were studied using a rainfall simulator and disc permeameter. The remnant H. contortus areas had higher infiltration characteristics mainly due to the maintenance of larger mncropores (1-3 mm). In the Arlstida patches, the contribution of those large macropores has been greatly reduced. Th is effect …

Evaluation Of Pastures For Sustained Beef Production In Subtropical New South Wales, P T. Mears, D L. Garden, R W. Dicker

IGC Proceedings (1977-2023)

Limitations of low-quality grass pastures, soil fertility, mechanisms of legume persistence and the long-term sustainability of pastures for beef production were studied in a humid subtropical environment of New South Wales, Australia. Sustainability of pastures and animal growth responses in 3 experiments (varying from 4 to 10 years' duration) al 2 sites have been analysed and described. Steers or heifers were used lo assess the effects of introducing subtropical or temperate legumes, level of superphosphate and stocking rate on natural grass pastures, Principal factors which improved the level of beef production from pasture were (i) introducing persistent legumes (ii) level …

Bothriochloa Pertusa- A Useful Grazing-Tolerant Grass For The Seasonally Dry Tropics?, R J. Jones, A Kerr

IGC Proceedings (1977-2023)

Data from 2 grazing experiments, small-plot studies, and a vegetation and soil survey showed that Bothriochloa pertusa increased relative to native tufted perennial grasses under heavy grazing pressure and was adapted to a wide range of soils in the 500-1000 mm zone of northern Australia. Ability to grow on low-P soils, lower relative palatability, strong stoloniferous development and good seed production, were features of its success. Annual steer gains on 8. pertusa pastures were similar to those on native pastures, with no species x stocking rate interaction. Steer gains on B. pertusa-Vernno stylo pastures were lower than on Urochloa …

Sustainability Of Sown Pastures In The Tropics And Subtropics, Jose M. Toledo, Daniel Formoso

IGC Proceedings (1977-2023)

Sown pastures in the tropics and subtropics are important components of production systems. Their role in and contribution to land productivity and economic development are well understood; however, their roles in sustainability and environmental protection are rather misunderstood and little known. The main constraints to sustainability of sown pastures fall into two categories: physical, biological and technical constraints include soil and climatic limitations, lack of adaptation of plants to physical and biotic stress and the limitations of farmers or ranchers to apply technology; socioeconomic factors include political instability, poorness of society and the market forces for land, inputs and products. …

Stability In Rangelands: Ecology And Economics, B H. Walker

IGC Proceedings (1977-2023)

Examples of changes in rangelands are presented relating to changes in livestock number, plant species. composition and soil changes (associated with changes in production), The mechanisms Involved are described, using examples, under the headings: event-driven change, threshold effects, non-linear and hysteresis effects, effects of spatial variation, significance of temporal variation, and interactive effects. The implications for management are presented in the form of a proposed optimal control model which maximises a complex function of welfnre based on long-term net economic benefit, in which stocking rate effects on the state of the rangeland feed back on to economic return.

Anthropological Analysis Of The Human Skeletal Remains From Naḥalat Ahim, Jerusalem (Pp. 121–124), Joe Zias

'Atiqot

The remains of 51 individuals were recovered from a Byzantine-period tomb at Naḥalat Ahim: 47% were adults, 40% were sub-adults and 4% were between 6–12 months; no neonates were identified. There was no discernible demographic pattern regarding age, sex or place of burial within the tomb. Two benign bone tumors were found in two different individuals; both types are previously unreported in excavations in Israel.

Diversity And Distribution Of Hydrocarbon-Degrading Genes In The Cold Seeps From The Mediterranean And Caspian Seas, Yogita Warkhade, Laura G. Schaerer, Isaac Bigcraft, Terry C. Hazen, Stephen M. Techtmann

Michigan Tech Publications

Marine cold seeps are unique ecological niches characterized by the emergence of hydrocarbons, including methane, which fosters diverse microbial communities. This study investigates the diversity and distribution of hydrocarbon-degrading genes and organisms in sediments from the Caspian and Mediterranean Seas, utilizing 16S rRNA and metagenomic sequencing to elucidate microbial community structure and functional potential. Our findings reveal distinct differences in hydrocarbon degrading gene profiles between the two seas, with pathways for aerobic and anaerobic hydrocarbon degradation co-existing in sediments from both basins. Aerobic pathways predominate in the surface sediments of the Mediterranean Sea, while anaerobic pathways are favored in the …

Real-Time Cbct Imaging And Motion Tracking Via A Single Arbitrarily-Angled X-Ray Projection By A Joint Dynamic Reconstruction And Motion Estimation (Dreme) Framework, Hua-Chieh Shao, Tielige Mengke, Tinsu Pan, You Zhang

Faculty, Staff and Student Publications

Objective: Real-time cone-beam computed tomography (CBCT) provides instantaneous visualization of patient anatomy for image guidance, motion tracking, and online treatment adaptation in radiotherapy. While many real-time imaging and motion tracking methods leveraged patient-specific prior information to alleviate under-sampling challenges and meet the temporal constraint (< 500 ms), the prior information can be outdated and introduce biases, thus compromising the imaging and motion tracking accuracy. To address this challenge, we developed a framework dynamic reconstruction and motion estimation (DREME) for real-time CBCT imaging and motion estimation, without relying on patient-specific prior knowledge.

Approach: DREME incorporates a deep learning-based real-time CBCT imaging and motion estimation method into a dynamic CBCT reconstruction framework. The reconstruction framework reconstructs a dynamic sequence of CBCTs in a data-driven manner from a standard pre-treatment scan, without requiring patient-specific prior knowledge. Meanwhile, a convolutional neural network-based motion encoder is jointly trained during the reconstruction …

The Association Between Thyroid Differentiation Score And Survival Outcomes In Papillary Thyroid Carcinoma, Jennifer R Wang, Mark E Zafereo, Maria E Cabanillas, Chia Chin Wu, Li Xu, Yaoyi Dai, Wenyi Wang, Stephen Y Lai, Ying Henderson, Lauren Erasmus, Michelle D Williams, Corinne Joshu, Debashree Ray

Faculty, Staff and Student Publications

Context: Thyroid differentiation score (TDS), calculated based on mRNA expression levels of 16 genes controlling thyroid metabolism and function, has been proposed as a measure to quantify differentiation in papillary thyroid carcinoma (PTC).

Objective: The objective of this study is to determine whether TDS is associated with survival outcomes across patient cohorts.

Methods: Two independent cohorts of patients with PTC were used: (1) The Cancer Genome Atlas (TCGA) thyroid cancer study (N = 372), (2) MD Anderson Cancer Center (MDACC) cohort (N = 111). The primary survival outcome of interest was progression-free interval (PFI). Association with overall survival (OS) was …

Conservation Of The Ancient Boat From The Sea Of Galilee, Orna Cohen

'Atiqot

The Galilee or Kinneret Boat, also dubbed “Jesus’ Boat,” was found and excavated in 1986. The various degrees of deterioration of the wood, the wood species and the size of the vessel were factors that reflected on the choice of the conservation method. Iron elements, such as nails, were also treated, and biological and bacterial problems were addressed. This report describes the chemical process of the conservation treatment of the wood and iron nails; the overcoming of biological and bacterial problems; and additional technical aspects of the conservation process. The report also describes the stages of preparation of the boat …

Biodiversity And Cold Tolerance Of Dung Beetles In Cattle Pastures And Forested Habitats In Northeast Arkansas, Becca Lynn Lett

Student Theses and Dissertations

Dung beetles play vital ecological roles, including dung removal and pest reduction. They rely on environmental temperature for activity, and forest habitats typically provide more favorable temperatures. This study occurred in Northeast Arkansas and compared dung beetle diversity in forests and pastures, finding greater diversity in forests. In addition, this study looked at abundance in one pasture 15 years apart and found that abundance remained stable over 15 years, while overall diversity increased. Thermal limit assays on three Onthophagus species provided insights into temperature tolerances. These findings offer valuable information on dung beetle abundance and diversity in the region and …

Timber Harvesting Was The Most Important Factor Driving Changes In Vegetation Composition, As Compared To Climate And Fire Regime Shifts, In The Mixedwood Temperate Forests Of Temiscamingue Since Ad 1830, Daniela Robles, Yan Boulanger, Jesus Pascual, Victor Danneyrolles, Yves Bergeron, Igor Drobyshev

Aspen Bibliography

Context The vegetation composition of northeastern North American forests has significantly changed since pre-settlement times, with a marked reduction in conifer-dominated stands, taxonomic and functional diversity. These changes have been attributed to fire regime shifts, logging, and climate change.

Methods In this study, we disentangled the individual effects of these drivers on the forest composition in southwestern Quebec from 1830 to 2000 by conducting retrospective modelling using the LANDIS-II forest landscape model. The model was run based on pre-settlement forest composition and fire history reconstructions, historical timber harvest records, and climate reanalysis data. We compared counterfactual scenarios excluding individual factors …

Behavioral Ecology And Physiology Of Spotted Turtles (Clemmys Guttata) In A Fragmented And Polluted Landscape, Jessica Rojas Lindberg

Master's Theses

Turtles are one of the most threatened groups of animals across the globe. This is especially true for freshwater turtles that rely on multiple habitats to fulfill their life history requirements. Wetlands are a crucial habitat type for many freshwater turtle species, and this ecosystem has been susceptible to conversion, fragmentation, and pollution. In turn, these hazards to wetland habitats threaten already declining freshwater turtle populations. The spotted turtle (Clemmys guttata) is a species of freshwater turtle that is particularly at-risk due to life history traits as well as habitat fragmentation and pollution. This study aims to investigate the effects …

Plasmodium Berghei Subpellicular Microtubule Protein-1 (Pbspm-1) Is A Microtubule Stabilizing Protein That Affects Schizont Development, Manuel Joseph Widuch

Master's Theses

In eukaryotes, microtubules (MTs) are regulated by microtubule-associated proteins (MAP), only a few of which have been characterized in the malaria parasite to date. Here we present the functional characterization of STOP axonemal protein 1 (SAXO1) of the rodent parasite Plasmodium berghei. The protein exhibits high sequence and organizational conservation to the subpellicular microtubule protein 1 (SPM1) of the apicomplexan parasite Toxoplasma gondii and SAXO1 of Trypanosoma brucei. SAXO1 proteins are conserved in most eukaryotes where they form a protein family. We refer to this protein as PbSPM1. It is a 38 kD protein that is organized into an N-terminal …

A Novel Case Of Glial Transdifferentiation In Renal Medullary Carcinoma Brain Metastasis, Maria A Gubbiotti, Ian E Mccutcheon, Priya Rao, Giannicola Genovese, Linghua Wang, Artem Tarasov, Vladislav Putintsev, Amber Berlinski, Danil Stupichev, Kirill Kriukov, Suren Davitavyan, Basim Salem, Alexander Sarachakov, Dmitry Lebedev, Michael Hensley, Alexander Bagaev, Francesca Paradiso, Vladimir Kushnarev, Gleb Khegai, Nizar M Tannir, Pavlos Msaouel

Faculty, Staff and Student Publications

Renal medullary carcinoma is a rare undifferentiated tumor of the kidney associated with sickle cell trait and characterized by INI1 (SMARCB1) loss. Although metastasis to lungs, lymph nodes, and bone is commonly reported, distant spread to the central nervous system almost never occurs. Here we present an unusual case of a patient with renal medullary carcinoma with metastasis to the brain following treatment which included tazemetostat, an EZH2 inhibitor. The metastatic brain lesion harbored morphologic, immunohistochemical, and methylation profile supportive of a primary CNS phenotype with loss of the trimethylated lysine 27 residue of histone 3 while maintaining INI1 loss …

A Climatically Significant Abiotic Mechanism Driving Carbon Loss And Nitrogen Limitation In Peat Bogs, Alexandra B. Cory, Rachel M. Wilson, M. Elizabeth Holmes, William J. Riley, Yueh Fen Li, Malak M. Tfaily, Sarah C. Bagby, Darya Anderson, Robert M. Jones, Gareth Trubl, Nicole Irwin-Raab, Sky Dominguez, Moira Hough, Virginia I. Rich, Matthew B. Sullivan, Maria F. Fahnestock, Suzanne B. Hodgkins, Ruth K. Varner, Michael Ibba, Regis Ferriere, Ahmed Zayed, Patrick M. Crill, Jessica G. Ernakovich, Jeffrey P. Chanton

Michigan Tech Publications

Sphagnum-dominated bogs are climatically impactful systems that exhibit two puzzling characteristics: CO2:CH4 ratios are greater than those predicted by electron balance models and C decomposition rates are enigmatically slow. We hypothesized that Maillard reactions partially explain both phenomena by increasing apparent CO2 production via eliminative decarboxylation and sequestering bioavailable nitrogen (N). We tested this hypothesis using incubations of sterilized Maillard reactants, and live and sterilized bog peat. Consistent with our hypotheses, CO2 production in the sterilized peat was equivalent to 8–13% of CO2 production in unsterilized peat, and the increased formation of aromatic N compounds decreased N-availability. Numerous sterility assessments …

Fast 3d Printing Of Fine, Continuous, And Soft Fibers Via Embedded Solvent Exchange, Wonsik Eom, Mohammad Tanver Hossain, Vidush Parasramka, Jeongmin Kim, Ryan W. Y. Siu, Kate A. Sanders, Dakota Piorkowski, Andrew Lowe, Hyun Gi Koh, Michael F. L. De Volder, Douglas S. Fudge, Randy H. Ewoldt, Sameh H. Tawfick

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Nature uses fibrous structures for sensing and structural functions as observed in hairs, whiskers, stereocilia, spider silks, and hagfish slime thread skeins. Here, we demonstrate multi-nozzle printing of 3D hair arrays having freeform trajectories at a very high rate, with fiber diameters as fine as 1.5 µm, continuous lengths reaching tens of centimeters, and a wide range of materials with elastic moduli from 5 MPa to 3500 MPa. This is achieved via 3D printing by rapid solvent exchange in high yield stress micro granular gel, leading to radial solidification of the extruded polymer filament at a rate of 2.33 μm/s. …

Scaling Arctic Landscape And Permafrost Features Improves Active Layer Depth Modeling, Wouter Hantson, Daryl Yang, Shawn P. Serbin, Joshua B. Fisher, Daniel J. Hayes

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Tundra ecosystems in the Arctic store up to 40% of global below-ground organic carbon but are exposed to the fastest climate warming on Earth. However, accurately monitoring landscape changes in the Arctic is challenging due to the complex interactions among permafrost, micro-topography, climate, vegetation, and disturbance. This complexity results in high spatiotemporal variability in permafrost distribution and active layer depth (ALD). Moreover, these key tundra processes interact at different scales, and an observational mismatch can limit our understanding of intrinsic connections and dynamics between above and below-ground processes. Consequently, this could limit our ability to model and anticipate how ALD …

The Clinical Utility Of A Next-Generation Sequencing-Based Approach To Detecting Circulating Hpv Dna In Patients With Advanced Anal Cancer, Deepak Bhamidipati, Jay R Johnson, Kangyu Lin, Helene Pelicano, Cathy Eng, Ryan Huey, Robert A Wolff, Daniel M Halperin, Michael F Frumovitz, Ignacio I Wistuba, Dzifa Y Duose, Saradhi Mallampati, Rajyalakshmi Luthra, Van K Morris

Faculty, Staff and Student Publications

Background: To extend the practicality of liquid biopsy beyond the historical HPV circulating tumor DNA (ctDNA) assays, we evaluated the clinical relevance of a novel next-generation sequencing HPV ctDNA assay in patients with locally advanced and metastatic squamous cell cancer of the anal canal (mSCCA).

Methods: ctDNA isolated from the plasma of patients with mSCCA was sequenced using a 1.4 Mb hybrid-capture target-enrichment panel covering the whole genome sequences of all 193 HPV types. The HPV type, copy number (CN), and integration sites were determined using a bioinformatic pipeline.

Results: A total of 77 plasma samples from 28 patients with …