Preliminary Evaluation of AIS Spectra Along a Topographic/moisture Gradient in the Nebraska Sandhills

Six spectral plots, each summarizing single-pixel reflectance for 128 channels of Airborne Imaging Spectrometer (AIS) data, were examined. The six sample pixels were located along a topographic/moisture gradient from lake surface to dune top in the Nebraska Sandhills. AIS spectra for various moisture regimes/vegetative zones appear quite logical, with a general positive relationship between increasing elevation (i.e., decreasing access of plant roots to water) and increasing reflectance in the spectral regions diagnostic of leaf-water content (i.e., bands centered on 1.65 and 2.20 microns)

Lichen Tour of Iowa State

For my project, I have sought to bridge the disconnect between technology and the natural world though the creation of “The Iowa State Lichen Trail”, which is hosted on a mobile friendly website. The website will guide, students, staff, faulty and visitors across ISU’s campus, stopping at multiple locations. Since most of the visitors will have never learned about this organism before, I have included a “getting to know us” and “basic anatomy” page to help orient visitors. At each stop, there are multiple pictures guiding the user to locate and identify the key features of the lichen. Each stop lists the names, both scientific and common, pertinent information about its ecology, and at several spots, how to distinguish the species from similar species. I collected, identified, and chose all the lichens represented on the webpage. I intentionally chose long-living, permanent lichen to ensure the trail can be enjoyed for the years to come

Bending of Pinus jeffrey in response to wind

"Aim of study: To evaluate the degree of trunk sway in relation to wind velocity, with varying temporal integration and to compare this relation among seasons. Area of study: Sierra de Juárez, Baja California, México Materials and Methods: Displacements of a 19 m tall Jeffrey pine tree were recorded at 6 m from a three dimensional digital compass during one year, at c. 4 Hz. Adjacent wind speed at 6 m was recorded at 1 Hz. Main results: Sway was essentially unaffected by wind in the same second but increasing dependence of cumulative displacement on average sustained wind speed was found for intervals of 1 to 60 minutes (r2 up to 0.89). The relation is nerally log-linear but apparently differs in parameters between seasons. Research highlights: Wind-sway relations are clear from integration of several-to-many minutes. However, to estimate cumulative stress, sub-second data on way are essential. Sub-second, precision measurements of sway can be registered from small, inexpensive sensors.

Experiences of young adults growing up with innate or early acquired HIV infection--a qualitative study

Aim. To explore the experience of young adults growing up and living with HIV in urban Sweden. Background. HIV has become a widespread pandemic. Effective antiretroviral treatment has dramatically increased the survival rate of infected individuals such that HIV-infection is currently considered a chronic disease where treatment is available. Data concerning the experience of living with HIV since early childhood is scarce and more empirical knowledge is needed in order to direct the development of adequate care and interventions for this growing demographic. Design. Exploratory qualitative study. Method. Semi-structured interviews were conducted with ten HIV-infected young adults over the period from January to August 2008. Transcripts of the interviews were analysed using qualitative content analysis. Findings. The analysis revealed five categories illustrating the experiences of growing up and living with HIV in Sweden: 1) to protect oneself from the risk of being stigmatised, 2) to be in control, 3) losses in life but HIV is not a big deal, 4) health care/health care providers, and 5) belief in the future. Conclusion. It is essential to offer a safe, trustworthy and professional health-care environment during the upbringing of HIV-infected children. Evidence-based interventions are needed to improve care and support, particularly regarding the handling of stigma and discrimination

Increased expression of the oxidative pentose phosphate pathway and gluconeogenesis in anaerobically growing xylose-utilizing Saccharomyces cerevisiae

<p>Abstract</p> <p>Background</p> <p>Fermentation of xylose to ethanol has been achieved in <it>S. cerevisiae </it>by genetic engineering. Xylose utilization is however slow compared to glucose, and during anaerobic conditions addition of glucose has been necessary for cellular growth. In the current study, the xylose-utilizing strain TMB 3415 was employed to investigate differences between anaerobic utilization of glucose and xylose. This strain carried a xylose reductase (<it>XYL1 </it>K270R) engineered for increased NADH utilization and was capable of sustained anaerobic growth on xylose as sole carbon source. Metabolic and transcriptional characterization could thus for the first time be performed without addition of a co-substrate or oxygen.</p> <p>Results</p> <p>Analysis of metabolic fluxes showed that although the specific ethanol productivity was an order of magnitude lower on xylose than on glucose, product yields were similar for the two substrates. In addition, transcription analysis identified clear regulatory differences between glucose and xylose. Respiro-fermentative metabolism on glucose during aerobic conditions caused repression of cellular respiration, while metabolism on xylose under the same conditions was fully respiratory. During anaerobic conditions, xylose repressed respiratory pathways, although notably more weakly than glucose. It was also observed that anaerobic xylose growth caused up-regulation of the oxidative pentose phosphate pathway and gluconeogenesis, which may be driven by an increased demand for NADPH during anaerobic xylose catabolism.</p> <p>Conclusion</p> <p>Co-factor imbalance in the initial twp steps of xylose utilization may reduce ethanol productivity by increasing the need for NADP+ reduction and consequently increase reverse flux in glycolysis.</p

Comparison of heterologous xylose transporters in recombinant Saccharomyces cerevisiae

Abstract Background Baker's yeast (Saccharomyces cerevisiae) has been engineered for xylose utilization to enable production of fuel ethanol from lignocellulose raw material. One unresolved challenge is that S. cerevisiae lacks a dedicated transport system for pentose sugars, which means that xylose is transported by non-specific Hxt transporters with comparatively low transport rate and affinity for xylose. Results In this study, we compared three heterologous xylose transporters that have recently been shown to improve xylose uptake under different experimental conditions. The transporters Gxf1, Sut1 and At5g59250 from Candida intermedia, Pichia stipitis and Arabidopsis thaliana, respectively, were expressed in isogenic strains of S. cerevisiae and the transport kinetics and utilization of xylose was evaluated. Expression of the Gxf1 and Sut1 transporters led to significantly increased affinity and transport rates of xylose. In batch cultivation at 4 g/L xylose concentration, improved transport kinetics led to a corresponding increase in xylose utilization, whereas no correlation could be demonstrated at xylose concentrations greater than 15 g/L. The relative contribution of native sugar transporters to the overall xylose transport capacity was also estimated during growth on glucose and xylose. Conclusions Kinetic characterization and aerobic batch cultivation of strains expressing the Gxf1, Sut1 and At5g59250 transporters showed a direct relationship between transport kinetics and xylose growth. The Gxf1 transporter had the highest transport capacity and the highest xylose growth rate, followed by the Sut1 transporter. The range in which transport controlled the growth rate was determined to between 0 and 15 g/L xylose. The role of catabolite repression in regulation of native transporters was also confirmed by the observation that xylose transport by native S. cerevisiae transporters increased significantly during cultivation in xylose and at low glucose concentration.</p

Hur har andrahandslägenheter i Malmö kommun fördelats till hemlösa över tid? : En studie av prioriteringar och exkluderingar

Under 1980-talet började flera svenska kommuner etablera en sekundär bostadsmarknad, där socialtjänsten hyrde ut lägenheter i andra hand till hemlösa klienter som var utestängda från den ordinarie bostadsmarknaden. Orsaken var en kombination av fastighetsägares ”höga trösklar”, socialtjänstens behov av boenden för hemlösa klienter och båda parters strävan efter kontroll. Möjligheten att tilldelas en lägenhet i andra hand var och är nämligen starkt villkorad från både bostadsföretagens och socialtjänstens sida. För hyresgästen präglas boendet också av osäkerhet: frånvaron av besittningsskydd, korta hyresperioder och tilläggsbestämmelser i hyresavtalet skiljer denna boendeform från vad som normalt gäller för hyresgäster, samtidigt som den utgör det högsta steget i en föreställd ”boendetrappa”.Rapporten är den första från forskningsprojektet Skånska hem vid Socialhögskolan,Lunds universitet, och undersöker hur de skånska kommunerna arbetar för att ordna bostäder till nyanlända respektive hemlösa. Författaren redogör för och analyserar Malmö kommuns uthyrning av andrahandslägenheter till hemlösa under en fyrtioårsperiod, från 1980-talets början och fram till halvårsskiftet 2021.Hur har socialtjänstens organisation förändrats över tid och vilka implikationer har det haft för detta bostadssegment? Vilka aktörer har deltagit i urvalet av hyresgäster till dessa bostäder och hur har de interagerat? Och hur har målgruppen för kommunens andrahandslägenheter kategoriserats över tid – vilka har prioriterats och vilka har exkluderats? Det är några av de frågor som väglett rapporten, och som besvaras genom en analys av ett stort antal intervjuer, dokument och observationer

Metabolic engineering of Saccharomyces cerevisiae ethanol strains PE-2 and CAT-1 for efficient lignocellulosic fermentation

In this work, Saccharomyces cerevisiae strains PE-2 and CAT-1, commonly used in the Brazilian fuel ethanol industry, were engineered for xylose fermentation, where the first fermented xylose faster than the latter, but also produced considerable amounts of xylitol. An engineered PE-2 strain (MEC1121) efficiently consumed xylose in presence of inhibitors both in synthetic and corn-cob hydrolysates. Interestingly, the S. cerevisiae MEC1121 consumed xylose and glucose simultaneously, while a CEN.PK based strain consumed glucose and xylose sequentially. Deletion of the aldose reductase GRE3 lowered xylitol production to undetectable levels and increased xylose consumption rate which led to higher final ethanol concentrations. Fermentation of corn-cob hydrolysate using this strain, MEC1133, resulted in an ethanol yield of 0.47 g/g of total sugars which is 92% of the theoretical yield.This work was supported by the Fundacao para a Ciencia e Tecnologia (FCT) through projects RECI/BBB-EBI/0179/2012-FCOMP-01-0124-FEDER-027462, PEst-OE/EQB/LA0023/2013, "Bio-Ind - Biotechnology and Bioengineering for improved Industrial and Agro-Food processes, REF. NORTE-07-0124-FEDER-000028" Co-funded by the Programa Operacional Regional do Norte (ON.2 - O Novo Norte) QREN, FEDER, PTDC/AAC-AMB/120940/2010, EXPL/BBB-BIO/1772/2013 and the FEDER POFC-COMPETE (PEst-C/BIA/UI4050/2011). A.R. was supported by FCT fellowship [SFRH/BPD/77995/2011] and F.P. by FCT fellowships [SFRH/BD/80934/2011 and SFRH/BD/42565/2007]